Research on Traction System for a Permanent Magnet Maglev Vehicle
Congestion of public transportation has always being an intractable problem especially in metropolises of China as it has the largest population.The primary shortcoming of automobile,which has always being the significant means of road transport, is its severe tail gas contamination. Electric vehicle has been considered as an ideal solution to environmental pollution but it is battery that hinders the popularization of electric vehicle. So far, there is no battery with all the advantages Tile magnets of high specific energy, high specific power, long cycle life, lower prices, security and pollution-free. In addition, another inevitable problem is traffic jam. No matter how wide the highroads are, how fast the highways are constructed, it is still riot sufficient for the rapidly increasing speed of China’s automobiles steering on roads for the moment.The advantages of permanent magnet maglev vehicle include lower capital cost estimate, high-speed & reliable operation, reduced environmental impact, excellent ride quality, lower energy consumption, reduced noise etc. It is the advantages that make permanent magnet maglev vehicle become one of the preferred solution to urban public transportation. Travel time of passengers can be guaranteed and there is no traffic jam because permanent magnet maglev vehicle operating at the speed of 160km/h operates on elevated guideway.As one of the key technologies of permanent magnet maglev vehicle, traction system implements power distribution and control that vehicle operation needs.
The research content of this dissertation is the preliminary exploration of traction technique of permanent magnet maglev vehicle. First of all, the author compares Germany’s maglev TR08 and Japan’s maglev MLX01 with permanent magnet maglev vehicle in the aspects such as suspension mechanism, capital cost estimate, maximum speed, acceleration, power consumption, capacity etc and consequently determines the scope of application of permanent magnent maglev vehicle. And then the author constitutes propulsion strategy according to the operation characteristic http://www.chinamagnets.biz/Neodymium/Tile-magnets.php of permanent magnet maglev vehicle. At the same time, the author also determines the configuration of propulsion and power supply system, the length of stator section, feeding strategy of multiple stator section and operation strategy of multiple vehicles etc. The power rating of traction system is calculated according to the requirements on the propulsion system. Subsequently, permanent magnet maglev vehicle traction system composed of 30 degree phase-shifting dual series connection thyristor rectifier and IEGT inverter is designed. In this dissertation, power semiconductor devices are also selected on the basis of the capacity of traction system. Besides the designed rectifier is analyzed and IEGT and its gate driver unit circuit are also introduced. Finally, simulation work is done on the basis of constituted simulation model of traction system of permanent magnet maglev vehicle. The simulation results prove that designed traction system meets the requirements on operation of permanent magnet maglev vehicle.
2012年10月31日星期三
The Permanent Magnet Synchronous Motor Line-starting Research
The Permanent Magnet Synchronous Motor Line-starting Research
Along with the new material, specially rare earth permanent-magnet material being published as well as unceasingly consummates, and the electric power electronic technology development cause the people to see the permanent magnet synchronous motor more and more. The permanent magnet synchronous motor has the structure to be simple, the movement reliable, the Block neodymium magnet volume small, the weight is light, loses slightly, the efficiency high and so on many merits. So its starting performance receives more and more electrical machinery user’s attention. At many conditions, the line-starting performance of permanent magnet synchronous motor becomes main index.
The line-starting process is complex.The torque includes not only asynchronous torque but also generation brake torque and single-axis torque. Except for them, there is pulsating torque during process. Because the line-starting process of the permanent magnet synchronous motor is very complex, this article researches the process from motion equation, electromagnetic field calculation and experiment test.At first, this article from permanent magnet synchronous motor line-start process, establishes permanent magnet synchronous motor dynamic process mathematical model; http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php Analyzes each parameter change situation in the line-start process as well as to permanent magnet synchronous machine influence; Establishes the dynamic process the equation of motion as well as the equivalent circuit. Uses the Runge-Kutta method to the equation of motion solution; Carries on the simulation using the Matlab language compilation procedure to permanent magnet synchronous motor line-start process.Then, using time-stepping finite element electromagnetic field analysis software Ansoft simulates the line-start process and generated electricity the brake torque for permanent magnet synchronous motor. Analyzes the position which maximum of the electricity generation brake torque appeared and permanent magnet synchronous motor the influence. Finally has conducted the experimental to permanent magnet synchronous motor line-start process. surveys permanent magnet synchronous motor the rotational speed, the torque and the phase current along during line-start process. And compares the measurement result to simulation curve.
Along with the new material, specially rare earth permanent-magnet material being published as well as unceasingly consummates, and the electric power electronic technology development cause the people to see the permanent magnet synchronous motor more and more. The permanent magnet synchronous motor has the structure to be simple, the movement reliable, the Block neodymium magnet volume small, the weight is light, loses slightly, the efficiency high and so on many merits. So its starting performance receives more and more electrical machinery user’s attention. At many conditions, the line-starting performance of permanent magnet synchronous motor becomes main index.
The line-starting process is complex.The torque includes not only asynchronous torque but also generation brake torque and single-axis torque. Except for them, there is pulsating torque during process. Because the line-starting process of the permanent magnet synchronous motor is very complex, this article researches the process from motion equation, electromagnetic field calculation and experiment test.At first, this article from permanent magnet synchronous motor line-start process, establishes permanent magnet synchronous motor dynamic process mathematical model; http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php Analyzes each parameter change situation in the line-start process as well as to permanent magnet synchronous machine influence; Establishes the dynamic process the equation of motion as well as the equivalent circuit. Uses the Runge-Kutta method to the equation of motion solution; Carries on the simulation using the Matlab language compilation procedure to permanent magnet synchronous motor line-start process.Then, using time-stepping finite element electromagnetic field analysis software Ansoft simulates the line-start process and generated electricity the brake torque for permanent magnet synchronous motor. Analyzes the position which maximum of the electricity generation brake torque appeared and permanent magnet synchronous motor the influence. Finally has conducted the experimental to permanent magnet synchronous motor line-start process. surveys permanent magnet synchronous motor the rotational speed, the torque and the phase current along during line-start process. And compares the measurement result to simulation curve.
Main Parameter Computation and Analysis of Disc Type Permanent Magnet Motor
Main Parameter Computation and Analysis of Disc Type Permanent Magnet Motor
Permanent magnet motor is a new style motor which take permanent magnet for excitation. However the shape and position of permanent magnet is various, and the magnetic structure is complicated, the computation and analysis of permanent magnet motor Ball Neodymium Magnets is more complicated than normal motor. The structure of disc type permanent magnet synchronous motor (PMSM) is different from traditional motor; its magnetic field problem is more complex. Therefore, it is necessary to research and investigate the effective method to analyze electromagnetic field of disc type permanent magnet motor, and it is significant and practical to improve the designing level of disc type permanent magnet motor.
The magnetic field distribution of disc type motor is axial, the computation of disc motor has to use 3D model. However 3D computation requires higher disposition of computer, it cannot be satisfied under normal conditions. In this paper, the 3D model of disc motor is simplified, and it can be equivalent into 2D steady and transient field to compute electromagnetic field. The simplified model can be testified right through experiment. Meanwhile, the thesis proposes the existing of zigzag leakage in multiple poles few slots PMSM, and summarizes the computation method of leakage factor. The leakage factor calculated by this method is identical to experiment value, whatever the structure of motor is radial or axial. On the basis of equivalent 2D model of disc type motor, the method to compute armature reaction reactance of radial PMSM has brought into computing steady state reactance of disc type motor, and it is tested to be practicable by experiment.When permanent motor http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php work on the state of starting, locked rotor and suddenly stalling etc., armature reaction of winding current will exert strong demagnetized action, and it will descend the work-point of permanent magnet outstandingly. The software Ansoft has been used to simulate 3-phase suddenly short-circuit process. A transient method has been submitted to check maximal demagnetize work point of permanent magnet, and it has been used to check two structure shape, radial and disc type, permanent magnet motor. Through experiment of radial permanent magnet motors, the method has been proved feasible, and it will supply a reliable base for permanent magnet motor designing.
Permanent magnet motor is a new style motor which take permanent magnet for excitation. However the shape and position of permanent magnet is various, and the magnetic structure is complicated, the computation and analysis of permanent magnet motor Ball Neodymium Magnets is more complicated than normal motor. The structure of disc type permanent magnet synchronous motor (PMSM) is different from traditional motor; its magnetic field problem is more complex. Therefore, it is necessary to research and investigate the effective method to analyze electromagnetic field of disc type permanent magnet motor, and it is significant and practical to improve the designing level of disc type permanent magnet motor.
The magnetic field distribution of disc type motor is axial, the computation of disc motor has to use 3D model. However 3D computation requires higher disposition of computer, it cannot be satisfied under normal conditions. In this paper, the 3D model of disc motor is simplified, and it can be equivalent into 2D steady and transient field to compute electromagnetic field. The simplified model can be testified right through experiment. Meanwhile, the thesis proposes the existing of zigzag leakage in multiple poles few slots PMSM, and summarizes the computation method of leakage factor. The leakage factor calculated by this method is identical to experiment value, whatever the structure of motor is radial or axial. On the basis of equivalent 2D model of disc type motor, the method to compute armature reaction reactance of radial PMSM has brought into computing steady state reactance of disc type motor, and it is tested to be practicable by experiment.When permanent motor http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php work on the state of starting, locked rotor and suddenly stalling etc., armature reaction of winding current will exert strong demagnetized action, and it will descend the work-point of permanent magnet outstandingly. The software Ansoft has been used to simulate 3-phase suddenly short-circuit process. A transient method has been submitted to check maximal demagnetize work point of permanent magnet, and it has been used to check two structure shape, radial and disc type, permanent magnet motor. Through experiment of radial permanent magnet motors, the method has been proved feasible, and it will supply a reliable base for permanent magnet motor designing.
2012年10月29日星期一
Study on PMSM Servo System Algorithms and System Design
Study on PMSM Servo System Algorithms and System Design
Permanent magnet synchronous motor (PMSM) has become the developing direction of servo drive in servo drive field. In order to obtain permanent magnet synchronous servo system with high performance and wide speed range, and to make the system posses better neodymium magnets flexibility and strengthen anti-jamming, new control strategies and control measures should be studied and applied in the system. This paper is aiming at high performance, wide speed range permanent magnet synchronous servo system.The control strategies of the vector control technique is analyzed and reached in this paper. The analyses show that the parameters in d and q axe are decoupling, the torque control characteristic is linear, output torque steady, the speed range wide when the vector control technique is applied in motion control system. To meet the demand of servo drive system, the vector control technique is chosen as the control strategy of permanent magnet synchronous servo system.Based on automation theory and PID control theory, the configuration and mathematical model of all parts of permanent magnet synchronous servo system are analyzed carefully. The three loops of the system are designed with the help of engineering design method of automation system regulator. The simulation of the system is taken; parameters of system regulator are analyzed in detail, joined with the influence of load and parameters disturbance on all the pats of the system.Sliding mode control strategy (SMC) is introduced, and several problems of SMC were also analyzed carefully. The position loop and speed http://www.chinamagnets.biz loop of servo system are redesigned, with the SMC and PID control strategy. In this case, we can improve the robustness of system. According to the experiment results, this new strategy can make the systems robust to the influence of load and parameters disturbance.This paper programmed based on the experimental apparatus and control algorithm, studied on the special functions including linear acceleration and deceleration, S-shape acceleration and deceleration, DC braking, parameter detecting, diagnosis and response of mal-function, finally the paper carried out solutions.
Permanent magnet synchronous motor (PMSM) has become the developing direction of servo drive in servo drive field. In order to obtain permanent magnet synchronous servo system with high performance and wide speed range, and to make the system posses better neodymium magnets flexibility and strengthen anti-jamming, new control strategies and control measures should be studied and applied in the system. This paper is aiming at high performance, wide speed range permanent magnet synchronous servo system.The control strategies of the vector control technique is analyzed and reached in this paper. The analyses show that the parameters in d and q axe are decoupling, the torque control characteristic is linear, output torque steady, the speed range wide when the vector control technique is applied in motion control system. To meet the demand of servo drive system, the vector control technique is chosen as the control strategy of permanent magnet synchronous servo system.Based on automation theory and PID control theory, the configuration and mathematical model of all parts of permanent magnet synchronous servo system are analyzed carefully. The three loops of the system are designed with the help of engineering design method of automation system regulator. The simulation of the system is taken; parameters of system regulator are analyzed in detail, joined with the influence of load and parameters disturbance on all the pats of the system.Sliding mode control strategy (SMC) is introduced, and several problems of SMC were also analyzed carefully. The position loop and speed http://www.chinamagnets.biz loop of servo system are redesigned, with the SMC and PID control strategy. In this case, we can improve the robustness of system. According to the experiment results, this new strategy can make the systems robust to the influence of load and parameters disturbance.This paper programmed based on the experimental apparatus and control algorithm, studied on the special functions including linear acceleration and deceleration, S-shape acceleration and deceleration, DC braking, parameter detecting, diagnosis and response of mal-function, finally the paper carried out solutions.
2012年10月25日星期四
Research on Explosive-proof Intelligent Vacuum Feed Switch Based on Permanent Magnetic Actuator
Research on Explosive-proof Intelligent Vacuum Feed Switch Based on Permanent Magnetic Actuator
Vacuum switch is widely used in the switch system and some other fields. It can be used for switching on and off the power system, monitoring the system to protect it from the malfunctions. Permanent magnetic actuator, synchronous closing and single chip technique are Ball Neodymium Magnets applied in the protection of vacuum switch. Using the principle of computer’s protective relaying in power system, a new kind of vacuum feed switch based on permanent magnetic actuator is developed, carrying out the functions of protecting, controlling, measuring, displaying, fixing, communication and self-diagnosis. This intelligent supervisory device with systems of communication and malfunction search has some functions such as earth leakage, short circuit，overload，phase failure，http://www.chinamagnets.biz over-voltage，under-voltage and so on, displaying the operating and failure status by LCD, and installing the system of error inquiry and communication. This paper analyzes the problem of magnetic compatibility for the device. The intelligent supervisory device applies in vacuum switch, improves the whole performance of the electrical equipment highly and makes a bright future for the intelligent supervisory computer used in power system.
Vacuum switch is widely used in the switch system and some other fields. It can be used for switching on and off the power system, monitoring the system to protect it from the malfunctions. Permanent magnetic actuator, synchronous closing and single chip technique are Ball Neodymium Magnets applied in the protection of vacuum switch. Using the principle of computer’s protective relaying in power system, a new kind of vacuum feed switch based on permanent magnetic actuator is developed, carrying out the functions of protecting, controlling, measuring, displaying, fixing, communication and self-diagnosis. This intelligent supervisory device with systems of communication and malfunction search has some functions such as earth leakage, short circuit，overload，phase failure，http://www.chinamagnets.biz over-voltage，under-voltage and so on, displaying the operating and failure status by LCD, and installing the system of error inquiry and communication. This paper analyzes the problem of magnetic compatibility for the device. The intelligent supervisory device applies in vacuum switch, improves the whole performance of the electrical equipment highly and makes a bright future for the intelligent supervisory computer used in power system.
The Research of Control System of Permanent Magnetic Synchronous Motors Applied in Ship Electric Propulsion
The Research of Control System of Permanent Magnetic Synchronous Motors Applied in Ship Electric Propulsion
In the near decades, with the rapid development of power electronic elements, high power converters as well as the advent of poded propulsion systems, ship electric propulsion has gradually become the main steam of future ships with several advantages such as higher flexibility of space arrangement, better maneuverability, higher driving efficiency and reduced fuel consumption.The research background in this paper was based on some domestic electric ship. Firstly, the neodymium magnets characteristics of thrust force and torque of poded propellers were analyzed, as well as the resistive characteristics of electric ship. Mathematical models and SIMULINK models were then established and treated as the main load of the whole system. A permanent magnetic synchronous motor (PMSM) was chosen as the driving motor of the system and hence the direct study object because of its excellent performance in variable speed of high power system. After that, mathematical models of a PMSM in different coordinate systems were analyzed here, as well as the basic principle and the implement method of direct torque control (DTC).
And then, a stator linkage observer which is based on the PID adaptive close-loop compensate method was also presented in order to effectively restrain the impact of observing linkage caused by DC offset.Three-level strategy was introduced here in order to cope with the problems of high torque ripple encountered in the traditional DTC systems. Firstly, http://www.chinamagnets.biz the basic principle of diode- clamped three-level inverter was given and the special problems aroused by DTC technique when it was applied in variable speed systems were also discussed. A simple feasible voltage vector selection scheme was provided in order to solve the problems of neutral voltage balance and restriction of voltage limitations and get a better control over them. At the end of the paper, the propeller model, the ship model and the three-level DTC model of PMSM were integrated. The whole simulation model of ship electric propulsion system based on three-level DTC technique was then established in the SIMULINK environment. Benefiting from the successful experiences of the Marine Automation and Simulator Research Institute of DMU, the author developed a distributed simulation system of ship electric propulsion system in VC++ environment. The comparisons of the results show that the three-level DTC has a better dynamic and static performance than traditional two-level DTC and hence validate the presented scheme.
In the near decades, with the rapid development of power electronic elements, high power converters as well as the advent of poded propulsion systems, ship electric propulsion has gradually become the main steam of future ships with several advantages such as higher flexibility of space arrangement, better maneuverability, higher driving efficiency and reduced fuel consumption.The research background in this paper was based on some domestic electric ship. Firstly, the neodymium magnets characteristics of thrust force and torque of poded propellers were analyzed, as well as the resistive characteristics of electric ship. Mathematical models and SIMULINK models were then established and treated as the main load of the whole system. A permanent magnetic synchronous motor (PMSM) was chosen as the driving motor of the system and hence the direct study object because of its excellent performance in variable speed of high power system. After that, mathematical models of a PMSM in different coordinate systems were analyzed here, as well as the basic principle and the implement method of direct torque control (DTC).
And then, a stator linkage observer which is based on the PID adaptive close-loop compensate method was also presented in order to effectively restrain the impact of observing linkage caused by DC offset.Three-level strategy was introduced here in order to cope with the problems of high torque ripple encountered in the traditional DTC systems. Firstly, http://www.chinamagnets.biz the basic principle of diode- clamped three-level inverter was given and the special problems aroused by DTC technique when it was applied in variable speed systems were also discussed. A simple feasible voltage vector selection scheme was provided in order to solve the problems of neutral voltage balance and restriction of voltage limitations and get a better control over them. At the end of the paper, the propeller model, the ship model and the three-level DTC model of PMSM were integrated. The whole simulation model of ship electric propulsion system based on three-level DTC technique was then established in the SIMULINK environment. Benefiting from the successful experiences of the Marine Automation and Simulator Research Institute of DMU, the author developed a distributed simulation system of ship electric propulsion system in VC++ environment. The comparisons of the results show that the three-level DTC has a better dynamic and static performance than traditional two-level DTC and hence validate the presented scheme.
2012年10月22日星期一
Research of Permanent Magnet Synchronous Motor Direct Torque Control Based on Fuzzy Logic
Research of Permanent Magnet Synchronous Motor Direct Torque Control Based on Fuzzy Logic
With the development of high performance permanent-magnet material, power electronic technique, large scale integrated-circuit and computer technology, the permanent magnet synchronous motor (PMSM) is widely used because of its small volume, high power density, high efficiency and power factor. Direct torque control (DTC) was put forward aiming at induction motor in the 1980s, it is another high performance control strategy for ac motor after vector control. Magnetic lifter With the solving of DTC strategy’s theoretical foundation in PMSM, the direct torque control of permanent magnet synchronous motor was concerned more and more.In this paper, the principle of coordinate transformation was introduced at first, and then the basic theory of PMSM DTC was discussed and the space voltage vector switching table of traditional DTC strategy was derived according to the model of PMSM.
Improved vector switching table of traditional DTC and introduced zero-voltage vector, which made torque keeping invariant, decreased action frequency of switching devices and improved control performance of system. Aiming at the fault of traditional DTC easily produced torque pulsation, the model of PMSM DTC based spaced vector modulation was given according to the foundation of space voltage vector modulation. Then the basic principle of fuzzy logic is introduced to the PMSM DTC. According to the feature that the flux hysteresis and torque hysteresis are fuzzy themselves, they can be fuzzified and the repository can be organized classically to complete the choice of space voltage vector.On the premise of theory analysis above, the simulation modules of flux and torque calculator, electromagnetic torque hysteresis, stator flux linkage hysteresis, sector http://www.999magnet.com choice and fuzzy controller of PMSM have been set up under the MATLAB/Simulink. The simulation of DTC control strategy with space vector modulation and fuzzy control are presented which demonstrate the fundamental theory of DTC control strategy for PMSM. The DTC of fuzzy control strategy and traditional control strategy are compared, the simulation results shows that fuzzy control strategy can decrease torque pulsation, improve dynamic and static performance of systems.On the basic of theoretical derivation and simulation verification, the hardware and software are designed for the digital signal processor (DSP)-based system. Furthermore, the DTC control system platform for PMSM is constructed. The hardware system of this paper includes main circuits, control circuits, drive circuits and measurement circuits. Then a driving experiment based SPWM and SVPWM is completed with drive board, to lay a foundation for further improvement.
With the development of high performance permanent-magnet material, power electronic technique, large scale integrated-circuit and computer technology, the permanent magnet synchronous motor (PMSM) is widely used because of its small volume, high power density, high efficiency and power factor. Direct torque control (DTC) was put forward aiming at induction motor in the 1980s, it is another high performance control strategy for ac motor after vector control. Magnetic lifter With the solving of DTC strategy’s theoretical foundation in PMSM, the direct torque control of permanent magnet synchronous motor was concerned more and more.In this paper, the principle of coordinate transformation was introduced at first, and then the basic theory of PMSM DTC was discussed and the space voltage vector switching table of traditional DTC strategy was derived according to the model of PMSM.
Improved vector switching table of traditional DTC and introduced zero-voltage vector, which made torque keeping invariant, decreased action frequency of switching devices and improved control performance of system. Aiming at the fault of traditional DTC easily produced torque pulsation, the model of PMSM DTC based spaced vector modulation was given according to the foundation of space voltage vector modulation. Then the basic principle of fuzzy logic is introduced to the PMSM DTC. According to the feature that the flux hysteresis and torque hysteresis are fuzzy themselves, they can be fuzzified and the repository can be organized classically to complete the choice of space voltage vector.On the premise of theory analysis above, the simulation modules of flux and torque calculator, electromagnetic torque hysteresis, stator flux linkage hysteresis, sector http://www.999magnet.com choice and fuzzy controller of PMSM have been set up under the MATLAB/Simulink. The simulation of DTC control strategy with space vector modulation and fuzzy control are presented which demonstrate the fundamental theory of DTC control strategy for PMSM. The DTC of fuzzy control strategy and traditional control strategy are compared, the simulation results shows that fuzzy control strategy can decrease torque pulsation, improve dynamic and static performance of systems.On the basic of theoretical derivation and simulation verification, the hardware and software are designed for the digital signal processor (DSP)-based system. Furthermore, the DTC control system platform for PMSM is constructed. The hardware system of this paper includes main circuits, control circuits, drive circuits and measurement circuits. Then a driving experiment based SPWM and SVPWM is completed with drive board, to lay a foundation for further improvement.
Study on the Rare Earth Permanent Magnet Synchronous Motor by FEM
Study on the Rare Earth Permanent Magnet Synchronous Motor by FEM
This dissertation develops partial contents of national 863 projects "The High Speed Highly Effective Explosion-proof Rare Earth Permanent Magnet Synchronous Motor". In order to improve the efficiency of rare earth permanent magnet synchronous motor (REPMSM), the paper combined FEM (Finite Element Method) with experiment methods, and studied on the copper losses of rotor of REPMSM in the steady-state, the starting process simulation of REPMSM, and the harmonic in air-gap magnetic field at no-load of REPMSM.The paper has calculated accurately a 22kW Segment neodymium magnets REPMSM in oil field for pumping with the FEM software MagNet. At the fist time, the copper losses of rotor in the steady-state of REPMSM because of the harmonic analyzed thoroughly, the direct and indirect method to measure the efficiency of the 22kW REPMSM is disposed for the harmonic losses. Compared the simulation and experiment result, the copper losses of rotor in steady-state of REPMSM existed actually. The idea is different from the traditional theory of REPMSM in the steady-state.The starting process simulation for the 22kW of the REPMSM with the FEM software of the MagNet is searched deeply. And the starting process experiment at no-load is completed, the measurement result proved the exactness of the simulation results. Simultaneously, the simulation result http://www.999magnet.com by the MagNet provided the reference to optimize REPMSM.The air-gap magnetic field at no-load of 370W REPMSM has simulated by the FEM software MagNet, the simulation results of THD (Total Harmonic Distortion) of back electromotive force at no-load was 6.23%. In order to prove the result of simulation, two 370W REPMSM had towed each other, the measurement results of THD was 3.26%.The damping effect to air gap harmonic was found by the rotor squirrel-cage bar.
This dissertation develops partial contents of national 863 projects "The High Speed Highly Effective Explosion-proof Rare Earth Permanent Magnet Synchronous Motor". In order to improve the efficiency of rare earth permanent magnet synchronous motor (REPMSM), the paper combined FEM (Finite Element Method) with experiment methods, and studied on the copper losses of rotor of REPMSM in the steady-state, the starting process simulation of REPMSM, and the harmonic in air-gap magnetic field at no-load of REPMSM.The paper has calculated accurately a 22kW Segment neodymium magnets REPMSM in oil field for pumping with the FEM software MagNet. At the fist time, the copper losses of rotor in the steady-state of REPMSM because of the harmonic analyzed thoroughly, the direct and indirect method to measure the efficiency of the 22kW REPMSM is disposed for the harmonic losses. Compared the simulation and experiment result, the copper losses of rotor in steady-state of REPMSM existed actually. The idea is different from the traditional theory of REPMSM in the steady-state.The starting process simulation for the 22kW of the REPMSM with the FEM software of the MagNet is searched deeply. And the starting process experiment at no-load is completed, the measurement result proved the exactness of the simulation results. Simultaneously, the simulation result http://www.999magnet.com by the MagNet provided the reference to optimize REPMSM.The air-gap magnetic field at no-load of 370W REPMSM has simulated by the FEM software MagNet, the simulation results of THD (Total Harmonic Distortion) of back electromotive force at no-load was 6.23%. In order to prove the result of simulation, two 370W REPMSM had towed each other, the measurement results of THD was 3.26%.The damping effect to air gap harmonic was found by the rotor squirrel-cage bar.
Study on the Key Technique in Design of Permanent Magnet Synchronous Motor for Metro
Study on the Key Technique in Design of Permanent Magnet Synchronous Motor for Metro
The thesis is devoted to exploiting study on the key technique in design of permanent magnet synchronous motor (PMSM) for metro. Three parts are included as follows:At first, the leakage coefficient of PMSM is accurately calculated by three-dimension finite element method (FEM). The leakage coefficient of PMSM is analyzed with factors change such as rotor structure, permanent magnet size, air-gap length and magnetic bridge size, and summarized the rule of leakage coefficient with structural parameter change. Which is useful for the rotor structure choice of PMSM for metro, Block Neodymium magnets as well as the leakage coefficient selection in electromagnetic calculation.ANSOFT is used to calculate the reactance parameters of PMSM in the second part. On the basis of the reactance parameters calculations of many permanent magnet synchronous motors, the change law and influencing factor of the reactance parameters with different rotor structure are analyzed, and the rule of the reactance parameters of PMSM is given. Which is good for selecting appropriate rotor structure, as well as enhancing the characteristics of motor.At last, the research work of PMSM for metro is carried out. The influence of motor type to the thermal load and the effective material peak-value power http://www.999magnet.com density is analyzed, and the dimensions of the motor are selected. The influence of different rotor structure to the reluctance torque is analyzed, and given the selection principle of the rotor structure. The influence of air-gap length to the permanent magnet quantity and the togging torque is analyzed, and given the select principle of air-gap length. The requirement for leakage reactance on stator of PMSM supplied by voltage type inverter is analyzed, and some parameters are selected, such as electromagnetic load, slots shape of stator and so on. The common method of enhancing the efficiency is given, such as decreasing the iron loss, copper loss and machine loss. Given some cautions on how to decrease the noise and vibration. From above all, a PMSM for metro isdesigned by field-circuit coupled method, and then the motor is analyzed and calculated by ANSOFT.
The thesis is devoted to exploiting study on the key technique in design of permanent magnet synchronous motor (PMSM) for metro. Three parts are included as follows:At first, the leakage coefficient of PMSM is accurately calculated by three-dimension finite element method (FEM). The leakage coefficient of PMSM is analyzed with factors change such as rotor structure, permanent magnet size, air-gap length and magnetic bridge size, and summarized the rule of leakage coefficient with structural parameter change. Which is useful for the rotor structure choice of PMSM for metro, Block Neodymium magnets as well as the leakage coefficient selection in electromagnetic calculation.ANSOFT is used to calculate the reactance parameters of PMSM in the second part. On the basis of the reactance parameters calculations of many permanent magnet synchronous motors, the change law and influencing factor of the reactance parameters with different rotor structure are analyzed, and the rule of the reactance parameters of PMSM is given. Which is good for selecting appropriate rotor structure, as well as enhancing the characteristics of motor.At last, the research work of PMSM for metro is carried out. The influence of motor type to the thermal load and the effective material peak-value power http://www.999magnet.com density is analyzed, and the dimensions of the motor are selected. The influence of different rotor structure to the reluctance torque is analyzed, and given the selection principle of the rotor structure. The influence of air-gap length to the permanent magnet quantity and the togging torque is analyzed, and given the select principle of air-gap length. The requirement for leakage reactance on stator of PMSM supplied by voltage type inverter is analyzed, and some parameters are selected, such as electromagnetic load, slots shape of stator and so on. The common method of enhancing the efficiency is given, such as decreasing the iron loss, copper loss and machine loss. Given some cautions on how to decrease the noise and vibration. From above all, a PMSM for metro isdesigned by field-circuit coupled method, and then the motor is analyzed and calculated by ANSOFT.
Studys of the Sm3(Fe,M)29Nx/α-Fe(M=Cr,V) Nanocomposite Permanent Magnetic Materials Prepared by Melt-Spun
Studys of the Sm3(Fe,M)29Nx/α-Fe(M=Cr,V) Nanocomposite Permanent Magnetic Materials Prepared by Melt-Spun
After the apearance of the nanocomposite permanet magnetic materials, with it’s perfect internal magnetism, it initiate a new power for the research of magnetic materials. The permanent magnetism is beyond the NdFeB, and the Curie temperature increased greatly, which provide optimistic foreground for the permanent materials. The amorphous band was perpared Ball Neodymium Magnets using the melt-spun method, and Sm3(Fe,M)29Nx/α-Fe (M=Cr,V) powders were carried out through the processing of crystalization and nitrification etc. The pocessing> detection and analysis method for Sm3(Fe,M)29Nx/α-Fe (M=Cr,V) magnetic materials were stuied detailedly. Adopting advanced detection method, author analysizes the microstructure and magnetic performance. The effect of addition element on microstructure and magnetic performance were stuied http://www.chinamagnets.biz basically.The minor elements were added befittingly, while the atom rate of addition element is below the 3.3% such as Sm3(Fe26.5Cr2V0.5)> Sm3(Fe26Cr2V1), the minor elements were steady in Sm3(Fe, M)29 phase and the rate of Sm3(Fe, M)29 and α-Fe was perfect. So the homogeneous amorphous made out by the melt spun, then the unanimous amorphous alloy was carried out. The uniform grain was fabricated out by crystalization. We got an advanced magnetic performance far-beyond the alloy in other component. When the atom rate of addition element is beyond the 3.3% as Sm3(Fe25.5Cr2V1.5) 、 Sm3(Fe25Cr2V2), the added elements enhance α-Fe phase consumingly, and debase the liquidity acutely, thus depress the magnetic performace.
After the apearance of the nanocomposite permanet magnetic materials, with it’s perfect internal magnetism, it initiate a new power for the research of magnetic materials. The permanent magnetism is beyond the NdFeB, and the Curie temperature increased greatly, which provide optimistic foreground for the permanent materials. The amorphous band was perpared Ball Neodymium Magnets using the melt-spun method, and Sm3(Fe,M)29Nx/α-Fe (M=Cr,V) powders were carried out through the processing of crystalization and nitrification etc. The pocessing> detection and analysis method for Sm3(Fe,M)29Nx/α-Fe (M=Cr,V) magnetic materials were stuied detailedly. Adopting advanced detection method, author analysizes the microstructure and magnetic performance. The effect of addition element on microstructure and magnetic performance were stuied http://www.chinamagnets.biz basically.The minor elements were added befittingly, while the atom rate of addition element is below the 3.3% such as Sm3(Fe26.5Cr2V0.5)> Sm3(Fe26Cr2V1), the minor elements were steady in Sm3(Fe, M)29 phase and the rate of Sm3(Fe, M)29 and α-Fe was perfect. So the homogeneous amorphous made out by the melt spun, then the unanimous amorphous alloy was carried out. The uniform grain was fabricated out by crystalization. We got an advanced magnetic performance far-beyond the alloy in other component. When the atom rate of addition element is beyond the 3.3% as Sm3(Fe25.5Cr2V1.5) 、 Sm3(Fe25Cr2V2), the added elements enhance α-Fe phase consumingly, and debase the liquidity acutely, thus depress the magnetic performace.
The Exploration of Nd-Fe-B Permanent Magnetic Materials
The Exploration of Nd-Fe-B Permanent Magnetic Materials
In this thesis, Nd-Fe-B permanent magnets are prepared by the means of vacuum sintering process. Otherwise, the influence of different additives and texture on performance are respectively studied.The samples are prepared as the element proportion (Pr-Nd)33.5Fe64.85B1.15A10.5 by smelting and casting, pneumatic milling for powder, doping and mixing sufficiently, orientation and forming, vacuum sintering, mechanical treatment and etc.
The experimental results shows: (1) In the same progress Neodymium Magnets of sintering, the coercivity of sintering magnet is firstly increased and then decreased with the increasing of A1N addition amount, whose maximum occurs in the point of 0.55%. but the remnant magnetism and magnetic energy product declined with its increasing. (2) The addition of Cu makes the same trend of coercivity with AIN, but the maximum appears in the point of 0.3%. (3) The maximum working temperature Tm of Nd-Fe-B has been computed by the theoretical formula and experimental parameter, through which the theoretical value of coercivity also has been computed indirectly.The crystal texture of magnetic body inevitably exists some difference by molding in different magnetic fields, which reflects the regular changes of mechanical properties in macro. As a result that Nd-Fe-B material belongs to the brittle material and has the high hardness, its mechanical properties may be improved by changing its http://www.999magnet.com crystal texture. The experimental result shows: (1) In different magnetic fields, the intensity of X-Ray diffraction peak of different crystal face perpendicular to the c-axis direction changes, in which the changes of (004), (105), (006) and (008) faces are obvious. (2) The magnetic properties of Nd-Fe-B change with different orientation of samples, in which the remanence falls, but the coercivity remain changeless.(3)The hardness of sample decreases with the increasing of orientation intensity, which shows some relationship between crystal texture and mechanical properties.This paper adopt Hitachi S-3400N SEM, DGN-3 DC Magnetic Testing Instrumentation, BDX3200 XRD, HV-120 Vickers Hardness, Hv-1 Micro-hardness to test the crystal phase, magnetic properties, orientation degree and hardness. The results show that the addition of AIN and Cu makes different effects on the coercivity and maximum working temperature of Nd-Fe-B permanent-magnetic material. In addition, the hardness and remnant magnetism of magnetic body exist some relationship with the crystal texture.
In this thesis, Nd-Fe-B permanent magnets are prepared by the means of vacuum sintering process. Otherwise, the influence of different additives and texture on performance are respectively studied.The samples are prepared as the element proportion (Pr-Nd)33.5Fe64.85B1.15A10.5 by smelting and casting, pneumatic milling for powder, doping and mixing sufficiently, orientation and forming, vacuum sintering, mechanical treatment and etc.
The experimental results shows: (1) In the same progress Neodymium Magnets of sintering, the coercivity of sintering magnet is firstly increased and then decreased with the increasing of A1N addition amount, whose maximum occurs in the point of 0.55%. but the remnant magnetism and magnetic energy product declined with its increasing. (2) The addition of Cu makes the same trend of coercivity with AIN, but the maximum appears in the point of 0.3%. (3) The maximum working temperature Tm of Nd-Fe-B has been computed by the theoretical formula and experimental parameter, through which the theoretical value of coercivity also has been computed indirectly.The crystal texture of magnetic body inevitably exists some difference by molding in different magnetic fields, which reflects the regular changes of mechanical properties in macro. As a result that Nd-Fe-B material belongs to the brittle material and has the high hardness, its mechanical properties may be improved by changing its http://www.999magnet.com crystal texture. The experimental result shows: (1) In different magnetic fields, the intensity of X-Ray diffraction peak of different crystal face perpendicular to the c-axis direction changes, in which the changes of (004), (105), (006) and (008) faces are obvious. (2) The magnetic properties of Nd-Fe-B change with different orientation of samples, in which the remanence falls, but the coercivity remain changeless.(3)The hardness of sample decreases with the increasing of orientation intensity, which shows some relationship between crystal texture and mechanical properties.This paper adopt Hitachi S-3400N SEM, DGN-3 DC Magnetic Testing Instrumentation, BDX3200 XRD, HV-120 Vickers Hardness, Hv-1 Micro-hardness to test the crystal phase, magnetic properties, orientation degree and hardness. The results show that the addition of AIN and Cu makes different effects on the coercivity and maximum working temperature of Nd-Fe-B permanent-magnetic material. In addition, the hardness and remnant magnetism of magnetic body exist some relationship with the crystal texture.
Research on Explosive-proof Intelligent Vacuum Feed Switch Based on Permanent Magnetic Actuator
Research on Explosive-proof Intelligent Vacuum Feed Switch Based on Permanent Magnetic Actuator
Vacuum switch is widely used in the switch system and some other fields. It can be used for switching on and off the power system, monitoring the system to protect it from the malfunctions. Permanent magnetic actuator, synchronous closing and single chip technique are Ball Neodymium Magnets applied in the protection of vacuum switch. Using the principle of computer’s protective relaying in power system, a new kind of vacuum feed switch based on permanent magnetic actuator is developed, carrying out the functions of protecting, controlling, measuring, displaying, fixing, communication and self-diagnosis. This intelligent supervisory device with systems of communication and malfunction search has some functions such as earth leakage, short circuit，overload，phase failure，http://www.chinamagnets.biz over-voltage，under-voltage and so on, displaying the operating and failure status by LCD, and installing the system of error inquiry and communication. This paper analyzes the problem of magnetic compatibility for the device. The intelligent supervisory device applies in vacuum switch, improves the whole performance of the electrical equipment highly and makes a bright future for the intelligent supervisory computer used in power system.
Vacuum switch is widely used in the switch system and some other fields. It can be used for switching on and off the power system, monitoring the system to protect it from the malfunctions. Permanent magnetic actuator, synchronous closing and single chip technique are Ball Neodymium Magnets applied in the protection of vacuum switch. Using the principle of computer’s protective relaying in power system, a new kind of vacuum feed switch based on permanent magnetic actuator is developed, carrying out the functions of protecting, controlling, measuring, displaying, fixing, communication and self-diagnosis. This intelligent supervisory device with systems of communication and malfunction search has some functions such as earth leakage, short circuit，overload，phase failure，http://www.chinamagnets.biz over-voltage，under-voltage and so on, displaying the operating and failure status by LCD, and installing the system of error inquiry and communication. This paper analyzes the problem of magnetic compatibility for the device. The intelligent supervisory device applies in vacuum switch, improves the whole performance of the electrical equipment highly and makes a bright future for the intelligent supervisory computer used in power system.
The Research of Control System of Permanent Magnetic Synchronous Motors Applied in Ship Electric Propulsion
The Research of Control System of Permanent Magnetic Synchronous Motors Applied in Ship Electric Propulsion
In the near decades, with the rapid development of power electronic elements, high power converters as well as the advent of poded propulsion systems, ship electric propulsion has gradually become the main steam of future ships with several advantages such as higher neodymium magnets flexibility of space arrangement, better maneuverability, higher driving efficiency and reduced fuel consumption.The research background in this paper was based on some domestic electric ship.
Firstly, the characteristics of thrust force and torque of poded propellers were analyzed, as well as the resistive characteristics of electric ship. Mathematical models and SIMULINK models were then established and treated as the main load of the whole system. A permanent magnetic synchronous motor (PMSM) was chosen as the driving motor of the system and hence the direct study object because of its excellent performance in variable speed of high power system. After that, mathematical models of a PMSM in different coordinate systems were analyzed here, as well as the basic principle and the implement method of direct torque control (DTC). And then, a stator linkage observer which is based on the PID adaptive close-loop compensate method was also presented in order to effectively restrain the impact of observing linkage caused by DC offset.Three-level strategy was introduced here in order to cope with the problems of high torque ripple encountered in the traditional DTC http://www.chinamagnets.biz systems. Firstly, the basic principle of diode- clamped three-level inverter was given and the special problems aroused by DTC technique when it was applied in variable speed systems were also discussed. A simple feasible voltage vector selection scheme was provided in order to solve the problems of neutral voltage balance and restriction of voltage limitations and get a better control over them. At the end of the paper, the propeller model, the ship model and the three-level DTC model of PMSM were integrated. The whole simulation model of ship electric propulsion system based on three-level DTC technique was then established in the SIMULINK environment. Benefiting from the successful experiences of the Marine Automation and Simulator Research Institute of DMU, the author developed a distributed simulation system of ship electric propulsion system in VC++ environment. The comparisons of the results show that the three-level DTC has a better dynamic and static performance than traditional two-level DTC and hence validate the presented scheme.
In the near decades, with the rapid development of power electronic elements, high power converters as well as the advent of poded propulsion systems, ship electric propulsion has gradually become the main steam of future ships with several advantages such as higher neodymium magnets flexibility of space arrangement, better maneuverability, higher driving efficiency and reduced fuel consumption.The research background in this paper was based on some domestic electric ship.
Firstly, the characteristics of thrust force and torque of poded propellers were analyzed, as well as the resistive characteristics of electric ship. Mathematical models and SIMULINK models were then established and treated as the main load of the whole system. A permanent magnetic synchronous motor (PMSM) was chosen as the driving motor of the system and hence the direct study object because of its excellent performance in variable speed of high power system. After that, mathematical models of a PMSM in different coordinate systems were analyzed here, as well as the basic principle and the implement method of direct torque control (DTC). And then, a stator linkage observer which is based on the PID adaptive close-loop compensate method was also presented in order to effectively restrain the impact of observing linkage caused by DC offset.Three-level strategy was introduced here in order to cope with the problems of high torque ripple encountered in the traditional DTC http://www.chinamagnets.biz systems. Firstly, the basic principle of diode- clamped three-level inverter was given and the special problems aroused by DTC technique when it was applied in variable speed systems were also discussed. A simple feasible voltage vector selection scheme was provided in order to solve the problems of neutral voltage balance and restriction of voltage limitations and get a better control over them. At the end of the paper, the propeller model, the ship model and the three-level DTC model of PMSM were integrated. The whole simulation model of ship electric propulsion system based on three-level DTC technique was then established in the SIMULINK environment. Benefiting from the successful experiences of the Marine Automation and Simulator Research Institute of DMU, the author developed a distributed simulation system of ship electric propulsion system in VC++ environment. The comparisons of the results show that the three-level DTC has a better dynamic and static performance than traditional two-level DTC and hence validate the presented scheme.
2012年10月15日星期一
The Design and Research of Servo System for Fin-Stabilizer Based on Permanent-Magnet Synchronal Motor
The Design and Research of Servo System for Fin-Stabilizer Based on Permanent-Magnet Synchronal Motor
The main work of this dissertation is to design the Electro-servo system of Fin-Stabilizer ,and to study the controller of the system by experiment.Due to it is a redesigned system, it must be debugged and experiment to make it accord with the design target. Alnico magnets At first, makes design of the Electro-servo system based on the design of Fin-Stabilizer and experiment system target. Designed and realized a system include with actuating unit, detection unit, monitoring equipment and control unit. Realized the function of servo-control, detection and data register.System model is needed by design of controller. In the dissertation, system model is found by system identification of step response. At first, order of model is decided through theory of electro-servo system transfer function. The closed loop transfer function is found by the system identification experiment of step http://www.999magnet.com response, and the open loop transfer function is found by it. In order to the need of identification experiment, PC Based PLC is used as a controller and an unit of data register.Based on the model of identification , PID controller is designed by Root Locus Rule and Ziegler—Nichol Rule. Through test of experiment step response, the system is meet the design requirements.
The main work of this dissertation is to design the Electro-servo system of Fin-Stabilizer ,and to study the controller of the system by experiment.Due to it is a redesigned system, it must be debugged and experiment to make it accord with the design target. Alnico magnets At first, makes design of the Electro-servo system based on the design of Fin-Stabilizer and experiment system target. Designed and realized a system include with actuating unit, detection unit, monitoring equipment and control unit. Realized the function of servo-control, detection and data register.System model is needed by design of controller. In the dissertation, system model is found by system identification of step response. At first, order of model is decided through theory of electro-servo system transfer function. The closed loop transfer function is found by the system identification experiment of step http://www.999magnet.com response, and the open loop transfer function is found by it. In order to the need of identification experiment, PC Based PLC is used as a controller and an unit of data register.Based on the model of identification , PID controller is designed by Root Locus Rule and Ziegler—Nichol Rule. Through test of experiment step response, the system is meet the design requirements.
Increment Information Predictive Control of Permanent Magnet Synchronous Motor
Increment Information Predictive Control of Permanent Magnet Synchronous Motor
Increment motion control is a kind of optimize control method under dynamic and uncertain conditions. For complex non-linear control problems, it is difficult to gain a satisfactory solution using classical linear control theory. Increment motion control is a multi-state control process. During the whole control time-field area, the system represents different states such as position, rate, neodymium magnets acceleration and so on. The control methods include step control, constant frequency control and rise-drop frequency control. Only under different states and reaching high precision control, the system could attain whole optimization.Predictive control is an advanced control system based on the model developing with the industry control practice.
The basic principle is based on predictive model with quadratic online to optimize the performance, then feedback emendate the predictive model. So predictive model, roll optimization and feedback emendation are basic factors of predictive control, which are also the key technologies for using it in practice successfully.Developing with the electronic and the micro-electronics technology, the basal mode of modern drive control has developed from continuous analog control to "DSP-IPM-motor" discrete digital control. The hypostasis of discrete control is accord with predict control. The uncertainty of the system can be overcome through predicting the change of the system and getting the corresponding control method based on the optimized performance, then correcting the http://www.chinamagnets.biz model using the practiced process dates. The application of predictive control could make the control object and control performance get implementing and optimization, parameters of system model get proper correction in every cycle.Increment motion control system refers to microsecond even nanosecond electronic apparatus switch transient process、 millisecond digital controller adjust process and second motor transition process. In unify time-order control, the system has discrete control characteristic. Because of the system complicacy, it make us have to range our research to find a better control method, which could against the control character and need lower requirement to math model, more convenient online calculation, better control effect and easier to integration. In this paper, presents the non-parameters modeling issue about increment motion system for the first time, use the dynamic matrix control (DMC) technique and obtain well control effect. It presents position-speed-current predictive control, and makes basic research in this area.
Increment motion control is a kind of optimize control method under dynamic and uncertain conditions. For complex non-linear control problems, it is difficult to gain a satisfactory solution using classical linear control theory. Increment motion control is a multi-state control process. During the whole control time-field area, the system represents different states such as position, rate, neodymium magnets acceleration and so on. The control methods include step control, constant frequency control and rise-drop frequency control. Only under different states and reaching high precision control, the system could attain whole optimization.Predictive control is an advanced control system based on the model developing with the industry control practice.
The basic principle is based on predictive model with quadratic online to optimize the performance, then feedback emendate the predictive model. So predictive model, roll optimization and feedback emendation are basic factors of predictive control, which are also the key technologies for using it in practice successfully.Developing with the electronic and the micro-electronics technology, the basal mode of modern drive control has developed from continuous analog control to "DSP-IPM-motor" discrete digital control. The hypostasis of discrete control is accord with predict control. The uncertainty of the system can be overcome through predicting the change of the system and getting the corresponding control method based on the optimized performance, then correcting the http://www.chinamagnets.biz model using the practiced process dates. The application of predictive control could make the control object and control performance get implementing and optimization, parameters of system model get proper correction in every cycle.Increment motion control system refers to microsecond even nanosecond electronic apparatus switch transient process、 millisecond digital controller adjust process and second motor transition process. In unify time-order control, the system has discrete control characteristic. Because of the system complicacy, it make us have to range our research to find a better control method, which could against the control character and need lower requirement to math model, more convenient online calculation, better control effect and easier to integration. In this paper, presents the non-parameters modeling issue about increment motion system for the first time, use the dynamic matrix control (DMC) technique and obtain well control effect. It presents position-speed-current predictive control, and makes basic research in this area.
Study on In-Wheel Transverse-Flux Permanent Magnet Machine (TFPMM) for EV
Study on In-Wheel Transverse-Flux Permanent Magnet Machine (TFPMM) for EV
On the background of energy crisis and pollution, Research on Electric Vehicle is very popular. Our country has spend a lot of money and manpower on it. neodymium magnets Transverse-Flux Permanent Magnet Machine (TFPMM) is a new type of machines with special magnetic topology developed in recent years. And TFPMM has high efficiency and high torque density which makes it suitable for the low speed and high torque application. The purpose of this thesis is to design an In-Wheel motor for EV base on a novel axial magnetized TFPMM. The main contents of this thesis are as follows:1. Background, meaning and advantages of the research.2. An overview on TFPMM, including operation principle, structure, topologies, equivalent circuit, present research and developing, disadvantages, etc.3. Study on magnet field of TFPMM by use of ANSYS. No-load operation, magnetizing http://www.chinamagnets.biz curve, flux leakage coefficient, additional air gap and the influences of different dimensions on flux are calculated.4. Mechanical design and manufacture of a new TFPMM prototype.5. Experimental test and analysis of the TFPMM. Tested data of the TFPMM such as no-load, loaded, Generator and synchronous motor are all obtained, and analyzed to evaluate performance the of TFPMM in detail.6. Modeling and simulating of TFPMM using Matlab/Simulink. In this way, the efficiency curve of TFPMM is drawn out by taking into account of the influence of the asymmetry EMF and the friction between the rotor and stator.Finally, we tempt to give a modified design proposal of TFPMM base on the results mentioned above.
On the background of energy crisis and pollution, Research on Electric Vehicle is very popular. Our country has spend a lot of money and manpower on it. neodymium magnets Transverse-Flux Permanent Magnet Machine (TFPMM) is a new type of machines with special magnetic topology developed in recent years. And TFPMM has high efficiency and high torque density which makes it suitable for the low speed and high torque application. The purpose of this thesis is to design an In-Wheel motor for EV base on a novel axial magnetized TFPMM. The main contents of this thesis are as follows:1. Background, meaning and advantages of the research.2. An overview on TFPMM, including operation principle, structure, topologies, equivalent circuit, present research and developing, disadvantages, etc.3. Study on magnet field of TFPMM by use of ANSYS. No-load operation, magnetizing http://www.chinamagnets.biz curve, flux leakage coefficient, additional air gap and the influences of different dimensions on flux are calculated.4. Mechanical design and manufacture of a new TFPMM prototype.5. Experimental test and analysis of the TFPMM. Tested data of the TFPMM such as no-load, loaded, Generator and synchronous motor are all obtained, and analyzed to evaluate performance the of TFPMM in detail.6. Modeling and simulating of TFPMM using Matlab/Simulink. In this way, the efficiency curve of TFPMM is drawn out by taking into account of the influence of the asymmetry EMF and the friction between the rotor and stator.Finally, we tempt to give a modified design proposal of TFPMM base on the results mentioned above.
2012年10月10日星期三
Reseach of Direct-Drive Permanent Magnet Synchronous Wind Turbine Generation Control System
Reseach of Direct-Drive Permanent Magnet Synchronous Wind Turbine Generation Control System
People widely pay more attention on wind energy because it is a regenerated energy. The variable-speed constant-frequency wind generation is very important in modern wind power system. It’s very suitable for wind generation because it can capture as much energy as possible. At present, direct-drive technology is the development trend of wind power generation system, but the electricity generated by direct-drive wind power generator has many problems, Such as voltage amplitude and frequency are changing with wind speed, the power is also unstable and so on.In order to solve these problems,The paper has done full-scale study on the direct-dirve variable-speed constant-frequency Block Neodymium magnets wind power generation from theory to simulation. The author has done thoroughly description on the characteristic of the direct-drive wind power generation and based on the existent Maximum Power Point Tracking Algorithm, established the topology configuration of Trapezoidal Permanent Synchronous Generator, three-phase uncontrolled Rectifier, DC-DC boost circuit, full-bridge Inverter circuit. A new Maximum Power Point Tracking Algorithm and speed-estimated control was put forward to increase the response of the system.The phase current of the generator is trapezoidal just for the inductance exit in the DC-DC boost circuit, in order to make the output power more stabilization, and reduce torque ripple, then EMF should be trapezoidal. The three-phase voltage is trapezoidal by the Trapezoidal Permanent Synchronous Generator, being commuted by the bridge of rectifier; Pulse is a series of smaller wave flattened. After was filter by large inductor, obtaining more flattered DC http://www.999magnet.com voltage.The generator and wind turbine can be coupled directly that has gained renewed attention on Large-Scale low speed wind power system;
Three-phase uncontrolled Rectifier has high realiability, simple hardware circuitry; DC-DC boost circuit can step up the DC link voltage to meet the Invert circuit, then connecting to the gird; Wind power generation vary with the change of the wind speed using Maximum Power Point Tracking algorithm, Maintain optimal tip-speed ratio, maximum power is captured from wind by the wind turbine.MATLAB/Simulink tool box is employed to construct the dynamic simulation modules for whole stall regulation wind turbine generator system so that the dynamic operation of the system may be simulated,Maximum Power Point Tracking algorithm is tested. The result of the simulation and experiment all validated the validity and feasibility of theoretical model and control strategy.
People widely pay more attention on wind energy because it is a regenerated energy. The variable-speed constant-frequency wind generation is very important in modern wind power system. It’s very suitable for wind generation because it can capture as much energy as possible. At present, direct-drive technology is the development trend of wind power generation system, but the electricity generated by direct-drive wind power generator has many problems, Such as voltage amplitude and frequency are changing with wind speed, the power is also unstable and so on.In order to solve these problems,The paper has done full-scale study on the direct-dirve variable-speed constant-frequency Block Neodymium magnets wind power generation from theory to simulation. The author has done thoroughly description on the characteristic of the direct-drive wind power generation and based on the existent Maximum Power Point Tracking Algorithm, established the topology configuration of Trapezoidal Permanent Synchronous Generator, three-phase uncontrolled Rectifier, DC-DC boost circuit, full-bridge Inverter circuit. A new Maximum Power Point Tracking Algorithm and speed-estimated control was put forward to increase the response of the system.The phase current of the generator is trapezoidal just for the inductance exit in the DC-DC boost circuit, in order to make the output power more stabilization, and reduce torque ripple, then EMF should be trapezoidal. The three-phase voltage is trapezoidal by the Trapezoidal Permanent Synchronous Generator, being commuted by the bridge of rectifier; Pulse is a series of smaller wave flattened. After was filter by large inductor, obtaining more flattered DC http://www.999magnet.com voltage.The generator and wind turbine can be coupled directly that has gained renewed attention on Large-Scale low speed wind power system;
Three-phase uncontrolled Rectifier has high realiability, simple hardware circuitry; DC-DC boost circuit can step up the DC link voltage to meet the Invert circuit, then connecting to the gird; Wind power generation vary with the change of the wind speed using Maximum Power Point Tracking algorithm, Maintain optimal tip-speed ratio, maximum power is captured from wind by the wind turbine.MATLAB/Simulink tool box is employed to construct the dynamic simulation modules for whole stall regulation wind turbine generator system so that the dynamic operation of the system may be simulated,Maximum Power Point Tracking algorithm is tested. The result of the simulation and experiment all validated the validity and feasibility of theoretical model and control strategy.
Electromagnetic Analysis of Low Speed Permanent Magnet Synchronous Motor
Electromagnetic Analysis of Low Speed Permanent Magnet Synchronous Motor
High torque performance permanent magnetic synchronous motor is a new typical electrical machine. Multipoles, low speed and high torque is its distinct characters. The technique of pole-slot match is applied to the motor, it can decrease the number of stator’s slot, and reduce motor’s volume, and raise motor’s power every volume.Along with the rapid scientific and technological development, and in some systems, such as: electric, machine of feed system and lift devices, the lower output of the electric motor speed is hoped. Moreover, the traditional AC motor is rotating at Neodymium Magnets a high speed, and they have 90% of the slowdown with the huge body matching can be used.
Gear motor, it will not increase the system size and weight, but also make noise and inertia increase, furthermore reduce efficiency and service life. Because of the precision gear meshing restrictions and the requirement in positive and steady and rapid response, gear rotational often affect system performance.The motor equips with Modular fractional slot windings. The concentrated winding of each phase is separately wound on consecutive teeth so that the phase windings don’t have overlap. This is not only a convenience of manufacture, but also the end of winding is shorter. The amount of copper and copper loss is reduced, so efficiency is high. It adopts this stator structure so that it can be made into relatively more pole number.Finite elment method is a numerical method, which is used to analyse structure or field. Its main idea that structure or field, which is made of consective dielectric, is http://www.999magnet.com discreted into elements that connected by limited nodal points to analyse. The method, which based on the theory of variation and the measure of discretizational resolver, invert conditional variation into object to resolve inner electromagnetic of the machine. The inner electromagnetic of high torque permanent brushless motor is resolved in this paper.From this study the basic structure of the electrical and basic theory, this paper discusses the steady-state performance of the motor, and analyzes the electromagnetic parameters impacting performance of motor. Through the air gap length, pole-arc coefficient, rotor magnets thickness, width of stator teeth and slot, the paper analyzes the impact of electromagnetic and Back Electromotive Force of the motor, summed up a different structure of the electrical parameters of the magnetic field distribution.
High torque performance permanent magnetic synchronous motor is a new typical electrical machine. Multipoles, low speed and high torque is its distinct characters. The technique of pole-slot match is applied to the motor, it can decrease the number of stator’s slot, and reduce motor’s volume, and raise motor’s power every volume.Along with the rapid scientific and technological development, and in some systems, such as: electric, machine of feed system and lift devices, the lower output of the electric motor speed is hoped. Moreover, the traditional AC motor is rotating at Neodymium Magnets a high speed, and they have 90% of the slowdown with the huge body matching can be used.
Gear motor, it will not increase the system size and weight, but also make noise and inertia increase, furthermore reduce efficiency and service life. Because of the precision gear meshing restrictions and the requirement in positive and steady and rapid response, gear rotational often affect system performance.The motor equips with Modular fractional slot windings. The concentrated winding of each phase is separately wound on consecutive teeth so that the phase windings don’t have overlap. This is not only a convenience of manufacture, but also the end of winding is shorter. The amount of copper and copper loss is reduced, so efficiency is high. It adopts this stator structure so that it can be made into relatively more pole number.Finite elment method is a numerical method, which is used to analyse structure or field. Its main idea that structure or field, which is made of consective dielectric, is http://www.999magnet.com discreted into elements that connected by limited nodal points to analyse. The method, which based on the theory of variation and the measure of discretizational resolver, invert conditional variation into object to resolve inner electromagnetic of the machine. The inner electromagnetic of high torque permanent brushless motor is resolved in this paper.From this study the basic structure of the electrical and basic theory, this paper discusses the steady-state performance of the motor, and analyzes the electromagnetic parameters impacting performance of motor. Through the air gap length, pole-arc coefficient, rotor magnets thickness, width of stator teeth and slot, the paper analyzes the impact of electromagnetic and Back Electromotive Force of the motor, summed up a different structure of the electrical parameters of the magnetic field distribution.
Numerical Analysis of Hysteresis Characteristic of Permanent Magnetic Materials in High Magnetic Field
Numerical Analysis of Hysteresis Characteristic of Permanent Magnetic Materials in High Magnetic Field
With the rapid improvement of the characteristics of permanent magnetic material, it is a kind of trend to use permanent magnetic material making permanent magnetic mechanism with high magnetic field strength. There is a kind of special permanent magnetic mechanism—magic ring which is made up of permanent magnet segments with different magnetization direction. A Ball Neodymium Magnets magnetic flux density level several times as much as the remanence B_r of permanent magnet material can be achieved, if we design the size of the magic ring properly.
The assembling process of magic ring is very complex. In the process of assembling the permanent magnetic structure, there exists a magnetization pattern in which the direction of local magnetic field varies arbitrarily due to the interaction of the magnet segments, and the demagnetization or saturation might occur at certain positions of the segments. The assembly process refers to rotational magnetization and vector hysteresis problem. There is a very little information available on the arbitrary two-dimensional magnetization case to permanent magnetic materials.The hysteresis characteristic of isotropic permanent magnetic materials under arbitrary applied field is numerically analyzed in this paper. As a result of the complexity of the assembly process of magic ring, the permanent http://www.chinamagnets.biz magnet segments are constrained to move according to predetermined mode. The paper analyzes numerically the assembly process of permanent magic ring combining Preisach hysteresis model with FEM, and applies hysteresis loop including minor loop to the numerical computation. The program is designed on the basis of FEM program using FORTRAN language. It is supposed that the normal component of the applied field has no effect on magnetization in the paper. Under this hypothesis hysteresis process with rotational magnetization is simulated.The paper analyzes the assembling process of magic ring which uses NdFeB and AlNiCo permanent magnetic materials with the new method presented. Also, the paper analyzes the assembling process of enhanced magic ring configuration proposed by our group. Compared with the traditional simplified method such as current sheet model, the new computation method has obtained the results with much more higher accuracy to simulate the actual properties of permanent magnetic material in high magnetic field.
With the rapid improvement of the characteristics of permanent magnetic material, it is a kind of trend to use permanent magnetic material making permanent magnetic mechanism with high magnetic field strength. There is a kind of special permanent magnetic mechanism—magic ring which is made up of permanent magnet segments with different magnetization direction. A Ball Neodymium Magnets magnetic flux density level several times as much as the remanence B_r of permanent magnet material can be achieved, if we design the size of the magic ring properly.
The assembling process of magic ring is very complex. In the process of assembling the permanent magnetic structure, there exists a magnetization pattern in which the direction of local magnetic field varies arbitrarily due to the interaction of the magnet segments, and the demagnetization or saturation might occur at certain positions of the segments. The assembly process refers to rotational magnetization and vector hysteresis problem. There is a very little information available on the arbitrary two-dimensional magnetization case to permanent magnetic materials.The hysteresis characteristic of isotropic permanent magnetic materials under arbitrary applied field is numerically analyzed in this paper. As a result of the complexity of the assembly process of magic ring, the permanent http://www.chinamagnets.biz magnet segments are constrained to move according to predetermined mode. The paper analyzes numerically the assembly process of permanent magic ring combining Preisach hysteresis model with FEM, and applies hysteresis loop including minor loop to the numerical computation. The program is designed on the basis of FEM program using FORTRAN language. It is supposed that the normal component of the applied field has no effect on magnetization in the paper. Under this hypothesis hysteresis process with rotational magnetization is simulated.The paper analyzes the assembling process of magic ring which uses NdFeB and AlNiCo permanent magnetic materials with the new method presented. Also, the paper analyzes the assembling process of enhanced magic ring configuration proposed by our group. Compared with the traditional simplified method such as current sheet model, the new computation method has obtained the results with much more higher accuracy to simulate the actual properties of permanent magnetic material in high magnetic field.
Studies on Manufacture Techniques for Sintered Nd-Fe-B Permanent Magnetic Materials with Low Production Cost and High Mechanical Properties
Studies on Manufacture Techniques for Sintered Nd-Fe-B Permanent Magnetic Materials with Low Production Cost and High Mechanical Properties
As a type of important functional material,sintered Nd-Fe-B permanent magnetic materials have outstanding magnetic properties, but its strength and toughness are poor which not only make it hard to machining, but also limit the applications. With the vehement market competition and low sale price,sintered Nd-Fe-B permanent magnetic materials have been given a lot of attention with the question of improving manufacture techniques to enhance production efficiency neodymium magnets and reduce production cost.In this paper, sintered Nd-Fe-B magnet samples with various magnetic properties have been manufactured on the mass-production line, and bending strength, impact toughness as well as fracture toughness has been tested, respectively. The fracture behavior and fracture mechanism have been studied by analyzing macroscopic and microcosmic characteristics of the magnets. The study shows that the formation, propagation and connection of micro-cracks lead to the fracture of sintered Nd-Fe-B materials. The micro-crack forms at grain boundary and propagates along grain boundary generally, while meet the grains with abnormal large size it will propagate through the matrix. The micro-cracks propagate through the matrix accelerate the fracture of the material.In this paper, the effects of sintering on magnetic and mechanical properties of Nd-Fe-B permanent magnetic materials have been investigated.
The effects of alloy element and microstructures on magnetic and mechanical properties of Nd-Fe-B permanent magnetic materials have been analyzed. Optimizing alloy compositions and sintering parameters to obtain Nd-Fe-B permanent magnetic materials with a microstructure of high compaction, homogeneous Nd-rich phase distribution, and fine well-knit http://www.chinamagnets.biz matrix grains can improve the magnetic and mechanical properties.N30 and N35 sintered Nd-Fe-B magnets which have a large sell market have been successfully mass-manufactured by adjusting alloy compositions and optimizing sintering and tempering processes parameters. It is proved that the products have steady magnetic properties and fine consistency. The magnets have fine microstructure with few holes and fine matrix grains. Bending strength of N30 and N35 magnets is about 316MPa and 327MPa, respectively. The magnets didn’t break or crack during machining, so the approved ratio is improved. Manufacture cost is reduced remarkably. Manufacture cost of N30 and N35 magnets is reduced by 35% and 4%, respectively.
As a type of important functional material,sintered Nd-Fe-B permanent magnetic materials have outstanding magnetic properties, but its strength and toughness are poor which not only make it hard to machining, but also limit the applications. With the vehement market competition and low sale price,sintered Nd-Fe-B permanent magnetic materials have been given a lot of attention with the question of improving manufacture techniques to enhance production efficiency neodymium magnets and reduce production cost.In this paper, sintered Nd-Fe-B magnet samples with various magnetic properties have been manufactured on the mass-production line, and bending strength, impact toughness as well as fracture toughness has been tested, respectively. The fracture behavior and fracture mechanism have been studied by analyzing macroscopic and microcosmic characteristics of the magnets. The study shows that the formation, propagation and connection of micro-cracks lead to the fracture of sintered Nd-Fe-B materials. The micro-crack forms at grain boundary and propagates along grain boundary generally, while meet the grains with abnormal large size it will propagate through the matrix. The micro-cracks propagate through the matrix accelerate the fracture of the material.In this paper, the effects of sintering on magnetic and mechanical properties of Nd-Fe-B permanent magnetic materials have been investigated.
The effects of alloy element and microstructures on magnetic and mechanical properties of Nd-Fe-B permanent magnetic materials have been analyzed. Optimizing alloy compositions and sintering parameters to obtain Nd-Fe-B permanent magnetic materials with a microstructure of high compaction, homogeneous Nd-rich phase distribution, and fine well-knit http://www.chinamagnets.biz matrix grains can improve the magnetic and mechanical properties.N30 and N35 sintered Nd-Fe-B magnets which have a large sell market have been successfully mass-manufactured by adjusting alloy compositions and optimizing sintering and tempering processes parameters. It is proved that the products have steady magnetic properties and fine consistency. The magnets have fine microstructure with few holes and fine matrix grains. Bending strength of N30 and N35 magnets is about 316MPa and 327MPa, respectively. The magnets didn’t break or crack during machining, so the approved ratio is improved. Manufacture cost is reduced remarkably. Manufacture cost of N30 and N35 magnets is reduced by 35% and 4%, respectively.
2012年10月8日星期一
Study and Design of Permanent Magnet Synchronous Motor Controller for Hybrid Electric Vehicle (HEV)
Study and Design of Permanent Magnet Synchronous Motor Controller for Hybrid Electric Vehicle (HEV)
In order to protect the environment that, the automotive green technique has become the hot mankind relies on, nowadays issue of the world. Especially current petroleum resources face to dry up, so the research and development of the green automobile has become the main direction of the world. The motor driving system is the one of the automotive key techniques, so it is profound to solve this key technique.This paper has investigated the basic principle of the direct torque neodymium magnets contro(lDTC) and studied the fuzzy zero vector distribute scheme for PMSM. Two novel DTC strategies that based on reference voltage vector scheme and reference flux linkage space voltage vector modulation scheme for PMSM are proposed. DTC strategy for asynchronous AC motor was proposed by the DTC scheme has resolved the complex problems that completely decoupled control of rotator magnet field orient in vector control scheme for ac motor .based DTC scheme the torque and stator flux linkage of the AC motor is controlled directly by selecting the voltage space vector properly, which http://www.chinamagnets.biz shows the better performances in high dynamic and steady state operation. DTC scheme has been widely used in the induction motor drive system.An Experimental system that using Motolola Company MC56F8367 as controller is designed. The main structures of the software and hardware parts of the control system are introduced. Principles and realization of the main functional blocks of these two parts are illuminated. On the hardware of the system, parts of control circuit and the design and debugging of peripheral circuits are discussed thoroughly. Based on the hardware circuit, the software is programmed with C language. Dual close loop vector control with feedback of speed and current are realized.
In order to protect the environment that, the automotive green technique has become the hot mankind relies on, nowadays issue of the world. Especially current petroleum resources face to dry up, so the research and development of the green automobile has become the main direction of the world. The motor driving system is the one of the automotive key techniques, so it is profound to solve this key technique.This paper has investigated the basic principle of the direct torque neodymium magnets contro(lDTC) and studied the fuzzy zero vector distribute scheme for PMSM. Two novel DTC strategies that based on reference voltage vector scheme and reference flux linkage space voltage vector modulation scheme for PMSM are proposed. DTC strategy for asynchronous AC motor was proposed by the DTC scheme has resolved the complex problems that completely decoupled control of rotator magnet field orient in vector control scheme for ac motor .based DTC scheme the torque and stator flux linkage of the AC motor is controlled directly by selecting the voltage space vector properly, which http://www.chinamagnets.biz shows the better performances in high dynamic and steady state operation. DTC scheme has been widely used in the induction motor drive system.An Experimental system that using Motolola Company MC56F8367 as controller is designed. The main structures of the software and hardware parts of the control system are introduced. Principles and realization of the main functional blocks of these two parts are illuminated. On the hardware of the system, parts of control circuit and the design and debugging of peripheral circuits are discussed thoroughly. Based on the hardware circuit, the software is programmed with C language. Dual close loop vector control with feedback of speed and current are realized.
Design of MW Grade Direct-Driven Permanent-Magnet Synchronous Generators for Wind Turbines
Design of MW Grade Direct-Driven Permanent-Magnet Synchronous Generators for Wind Turbines
Without the typical gearbox in wind-generating system and the disadvantages caused by gearbox, the PMSG (permanent magnetic Synchronous generator) is directly driven by the wind turbine at low speed, which makes the operation of the generator more liable. PMSG is different with salient pole Synchronous generator and its poles are made of the rare earth material with Neodymium Magnets high BH product, which avoids the excitation losses, makes the generator structure simpler with high efficiency.Direct-driven PMSG works at low speed and its size is generally big. In this paper, the inner-rotor structure is selected for the convenient transportation and good cooling. Firstly the design goal is proposed and it is to improve the generator liability and lower the cost on the precondition that match with the basic generator parameter requirements. Then a program is developed http://www.999magnet.com on the theory of EMCM (equivalent magnetic circuit method) and it is used in the pre-design of the PMSG. Thirdly generator characterizes are analyzed on different working condition with FEA (finite element analyze). Finally, the air-cooling system is designed and air rate is calculated.
Without the typical gearbox in wind-generating system and the disadvantages caused by gearbox, the PMSG (permanent magnetic Synchronous generator) is directly driven by the wind turbine at low speed, which makes the operation of the generator more liable. PMSG is different with salient pole Synchronous generator and its poles are made of the rare earth material with Neodymium Magnets high BH product, which avoids the excitation losses, makes the generator structure simpler with high efficiency.Direct-driven PMSG works at low speed and its size is generally big. In this paper, the inner-rotor structure is selected for the convenient transportation and good cooling. Firstly the design goal is proposed and it is to improve the generator liability and lower the cost on the precondition that match with the basic generator parameter requirements. Then a program is developed http://www.999magnet.com on the theory of EMCM (equivalent magnetic circuit method) and it is used in the pre-design of the PMSG. Thirdly generator characterizes are analyzed on different working condition with FEA (finite element analyze). Finally, the air-cooling system is designed and air rate is calculated.
Preparation and Properties of Sintered Sm(Co0.717Fe0.15Cu0.10Zr0.033)7.2 Permanent Magnets with ZrB2 Addition
Preparation and Properties of Sintered Sm(Co0.717Fe0.15Cu0.10Zr0.033)7.2 Permanent Magnets with ZrB2 Addition
New-type 2:17 SmCo permanent magnets are the best choice in high tempweature application area because of its high magnetic properties,good temperature stability, high curie temperature(about 825℃)and low temperature coefficient.But its low strength and toughness leads to poor machinability and costly fabrication, and limit its use in some rigorous area.Up to now, there is quite few studies on strength and toughness of this materials and the mechanism of fracture is not Ball Neodymium Magnets determined. The systematic investigations on the improvement of sintered SmCo permanent magnetic materials have been rarely reported.In this paper,the magnets were prepared by powder metallurgy .Powders of ZrB2 wereadded during ball milling process.The effect of ZrB2 addition on the sinter and heat treatment technics, magnetics and mechanics properties were intensively studied.
The magnetic properties and fracture toughness were measured, the microstructure and fracture surfaces were observed by SEM.The results showed that the sintering and heating treatment technics, magnetics and mechanics properties were affectted in different degree by the addition of ZrB2.Some of the ZrB2 particles distributed uniformly in the alloy,and the others decomposed to combine with Fe、Co to form low-melting point Co-Zr-Fe-B phase,which was helpful to accelerate the pyknosis process of the alloy,beacause of the change from solid-phase sintering to liquid-phase sintering,and lower the optimal sintering and heat treatment temperatures.With the http://www.chinamagnets.biz addition of ZrB2, the room-temperature magnetic properties of the magnets were increased sharply than the magnets without ZrB2 addition. The optimal sinter and heat treatment processes of the alloy with 0.5%ZrB2was sintered at 1190℃for 15min, heat treated at 1150℃for 2h. The magnetic properties of this magnet were Br≈0.906T, Hcb≈618kA/m, Hci≈1976 kA/m, (BH)m≈140 kJ/m3,and the temperature coefficientα(27-200℃)≈-0.028%/℃、β(27-200)℃≈-0.031%/℃of magnet with 0.5%ZrB2 was achieved.At the same time, the fracture toughness were increased obviously with the addition of ZrB2, however, the fracture mechanism of magnets still was cleavage fracture. The improvement of the fracture toughness could be attributed partly to the increase of grain boundary thickness and bond strength, and the other to the dispersion strengthening of ZrB2 particlesIn addition, The method of ball milling with refractory powerders was introduce to improve the mechanical propertie of the sintered SmCo permanent magnets, andimprovement of toughness was obtained without hazard to the magnetic properties.
New-type 2:17 SmCo permanent magnets are the best choice in high tempweature application area because of its high magnetic properties,good temperature stability, high curie temperature(about 825℃)and low temperature coefficient.But its low strength and toughness leads to poor machinability and costly fabrication, and limit its use in some rigorous area.Up to now, there is quite few studies on strength and toughness of this materials and the mechanism of fracture is not Ball Neodymium Magnets determined. The systematic investigations on the improvement of sintered SmCo permanent magnetic materials have been rarely reported.In this paper,the magnets were prepared by powder metallurgy .Powders of ZrB2 wereadded during ball milling process.The effect of ZrB2 addition on the sinter and heat treatment technics, magnetics and mechanics properties were intensively studied.
The magnetic properties and fracture toughness were measured, the microstructure and fracture surfaces were observed by SEM.The results showed that the sintering and heating treatment technics, magnetics and mechanics properties were affectted in different degree by the addition of ZrB2.Some of the ZrB2 particles distributed uniformly in the alloy,and the others decomposed to combine with Fe、Co to form low-melting point Co-Zr-Fe-B phase,which was helpful to accelerate the pyknosis process of the alloy,beacause of the change from solid-phase sintering to liquid-phase sintering,and lower the optimal sintering and heat treatment temperatures.With the http://www.chinamagnets.biz addition of ZrB2, the room-temperature magnetic properties of the magnets were increased sharply than the magnets without ZrB2 addition. The optimal sinter and heat treatment processes of the alloy with 0.5%ZrB2was sintered at 1190℃for 15min, heat treated at 1150℃for 2h. The magnetic properties of this magnet were Br≈0.906T, Hcb≈618kA/m, Hci≈1976 kA/m, (BH)m≈140 kJ/m3,and the temperature coefficientα(27-200℃)≈-0.028%/℃、β(27-200)℃≈-0.031%/℃of magnet with 0.5%ZrB2 was achieved.At the same time, the fracture toughness were increased obviously with the addition of ZrB2, however, the fracture mechanism of magnets still was cleavage fracture. The improvement of the fracture toughness could be attributed partly to the increase of grain boundary thickness and bond strength, and the other to the dispersion strengthening of ZrB2 particlesIn addition, The method of ball milling with refractory powerders was introduce to improve the mechanical propertie of the sintered SmCo permanent magnets, andimprovement of toughness was obtained without hazard to the magnetic properties.
Electromagnetic Field Analyse of Modular Stator Structure Low Speed Permanent Magnet Bureshless Direct Cuurent Motor
Electromagnetic Field Analyse of Modular Stator Structure Low Speed Permanent Magnet Bureshless Direct Cuurent Motor
Modular stator structure low speed permanent magentic brushless direct current motor is a new topology of electrical machine. Multipoles, low speed and high torque is its distinct characters. It adopts modular stator structure so that it can be made into relatively more pole number. There are several small armature projections whose dimension is 1/3 of pole pitch in the stator, which cause others stator teeth pitch is full pole pitch and induced electromotive force waveform neodymium magnets of each phase is approach trapeze wave. The tooth width of the motor is one full pole pitch and armature windings is full pole pitch concentrated windings so that winding coefficient is 1 and utility efficient of windings is higher. The concentrated winding of each phase is separately wound on consective teeth so that the phase windings don’t have overlap.
This is not only a convenience of manufacture, but also the end of winding is shorter. The aount of copper and copper loss are reduced, so efficiency is high.Finite elment method is a numerical method, which is used to analyse structure or field. Its main idea that structure or field, which is made of consective dielectric, is discreted into elements that connected by limited nodal points to analyse. The method, which based on the theory of variation and the measure of discretizational resolver, invert conditional variation into object to resolve inner electromagnetic of the machine. The inner electromagnetic of modular stator structure low speed permanent brushless motor is resolved in this paper.The structure of the machine is mainly discussed in this paper. The relation between topology structural parameter and poles number of the machine is brought forward and cogging torque and http://www.chinamagnets.biz corresponding induced electromotive force are concluded. After the calculation and analysis of different dimensional air-gap magnetic field of this machine, design data of the machine is presented and structure design and magnetic circuit calculation of the machine is completed. The resolve result indicate that phase induced electromotive force waveform of three phase stator winding is trapezoidal wave, and the flat-topping is approach to 2π/3 electrical angel. The result also approved that there are only three and triple cogging torque in the machine; the others cogging torque is eliminated. Beause of the merits above-mentioned, this kind of stator strcture permanent magnetic electrical machine is especially suited to be low speed and high torque direct cuurent brushless motor or direct drive wind generator.
Modular stator structure low speed permanent magentic brushless direct current motor is a new topology of electrical machine. Multipoles, low speed and high torque is its distinct characters. It adopts modular stator structure so that it can be made into relatively more pole number. There are several small armature projections whose dimension is 1/3 of pole pitch in the stator, which cause others stator teeth pitch is full pole pitch and induced electromotive force waveform neodymium magnets of each phase is approach trapeze wave. The tooth width of the motor is one full pole pitch and armature windings is full pole pitch concentrated windings so that winding coefficient is 1 and utility efficient of windings is higher. The concentrated winding of each phase is separately wound on consective teeth so that the phase windings don’t have overlap.
This is not only a convenience of manufacture, but also the end of winding is shorter. The aount of copper and copper loss are reduced, so efficiency is high.Finite elment method is a numerical method, which is used to analyse structure or field. Its main idea that structure or field, which is made of consective dielectric, is discreted into elements that connected by limited nodal points to analyse. The method, which based on the theory of variation and the measure of discretizational resolver, invert conditional variation into object to resolve inner electromagnetic of the machine. The inner electromagnetic of modular stator structure low speed permanent brushless motor is resolved in this paper.The structure of the machine is mainly discussed in this paper. The relation between topology structural parameter and poles number of the machine is brought forward and cogging torque and http://www.chinamagnets.biz corresponding induced electromotive force are concluded. After the calculation and analysis of different dimensional air-gap magnetic field of this machine, design data of the machine is presented and structure design and magnetic circuit calculation of the machine is completed. The resolve result indicate that phase induced electromotive force waveform of three phase stator winding is trapezoidal wave, and the flat-topping is approach to 2π/3 electrical angel. The result also approved that there are only three and triple cogging torque in the machine; the others cogging torque is eliminated. Beause of the merits above-mentioned, this kind of stator strcture permanent magnetic electrical machine is especially suited to be low speed and high torque direct cuurent brushless motor or direct drive wind generator.
Research on the High-Precision Control of Permanent Magnet Linear Servo System
Research on the High-Precision Control of Permanent Magnet Linear Servo System
In modern machining industry, laser-cutting, high-speed milling and scanning machines require fast and accurate linear motions. But traditional drives need to use rotational motors and lead screw or toothed belts to obtain linear motions, which leads to some mechanical problems such as backlash, large frictional, inertial loads and structural flexibilities. With the development of linear motors, recently, they are becoming increasingly popular in such applications. Due to the direct-drive technology, linear motor exhibits the property of high accuracy, high speed and excellent dynamic neodymium magnets responsivity, which just satisfies the requirement of high speed machining (HSM). In order to explore the linear motor applications in machining tools, here, we designed a linear servo system via selecting a permanent magnet synchronous linear motor (PMSLM) and a linear encoder. Our aim is to develop some algorithms to realize high accuracy and high performance control for this linear servo system.First, we applied field-oriented principle and the strategy of i_d = 0 to the state space model of PMSLM in d-q coordinates, and obtained a decoupling model and an approximate linearization model in frequency domain of the motor and driver system. Based on these models, we designed a robust PID controller of speed-loop by means of H_∞closed-loop gain shaping techniques.
Moreover, a speed feed-forward block could be obtained easily from the frequency domain model of PMSLM and its driver. The robust PID controller exhibits good robustness against external disturbances and internal parameter perturbation by simulation results. When the feed-forward block is added, the responsive speed and control accuracy of the system will be improved more. Moreover, a pseudo derivative feed-forward (PDFF) method is analyzed in this thesis. As a type of PI control with feed-forward, PDFF can be designed independently from the plant model which is very suitable for engineering applications. Due to the pseudo derivative item of speed feedback, the dynamic performance and noise control of PDFF is improved greatly.In order to realize the high accurate http://www.chinamagnets.biz position control, firstly, we made a speed plan through which a speed curve can be obtained from a displacement order. According to speed loop control, we design a P/PI position and speed control system with speed and acceleration double feed-forward path. The feed-forward paths provide the main control signals, speed order signal to the input terminal of speed loop and acceleration signal to the input terminal of current loop, and the main path controls the error of position and speed. Simulation results show that the double closed-loop system has strong robustness and excellent control performance with the dynamic error less than 10μm and static error near to zero. There are five major control parameters in this system, here, these parameters are optimized with genetic algorithm and the satisfied results are achieved. Furthermore, the method of PDFF is investigated, but its accuracy is less than that of above method.This thesis has completed the main design work of the linear servo system from the selections and installations of equipments to the design of control algorithms and the optimization of their parameters. After these work, we will continue to apply these algorithm to the experiment system and realize the design target of system.
In modern machining industry, laser-cutting, high-speed milling and scanning machines require fast and accurate linear motions. But traditional drives need to use rotational motors and lead screw or toothed belts to obtain linear motions, which leads to some mechanical problems such as backlash, large frictional, inertial loads and structural flexibilities. With the development of linear motors, recently, they are becoming increasingly popular in such applications. Due to the direct-drive technology, linear motor exhibits the property of high accuracy, high speed and excellent dynamic neodymium magnets responsivity, which just satisfies the requirement of high speed machining (HSM). In order to explore the linear motor applications in machining tools, here, we designed a linear servo system via selecting a permanent magnet synchronous linear motor (PMSLM) and a linear encoder. Our aim is to develop some algorithms to realize high accuracy and high performance control for this linear servo system.First, we applied field-oriented principle and the strategy of i_d = 0 to the state space model of PMSLM in d-q coordinates, and obtained a decoupling model and an approximate linearization model in frequency domain of the motor and driver system. Based on these models, we designed a robust PID controller of speed-loop by means of H_∞closed-loop gain shaping techniques.
Moreover, a speed feed-forward block could be obtained easily from the frequency domain model of PMSLM and its driver. The robust PID controller exhibits good robustness against external disturbances and internal parameter perturbation by simulation results. When the feed-forward block is added, the responsive speed and control accuracy of the system will be improved more. Moreover, a pseudo derivative feed-forward (PDFF) method is analyzed in this thesis. As a type of PI control with feed-forward, PDFF can be designed independently from the plant model which is very suitable for engineering applications. Due to the pseudo derivative item of speed feedback, the dynamic performance and noise control of PDFF is improved greatly.In order to realize the high accurate http://www.chinamagnets.biz position control, firstly, we made a speed plan through which a speed curve can be obtained from a displacement order. According to speed loop control, we design a P/PI position and speed control system with speed and acceleration double feed-forward path. The feed-forward paths provide the main control signals, speed order signal to the input terminal of speed loop and acceleration signal to the input terminal of current loop, and the main path controls the error of position and speed. Simulation results show that the double closed-loop system has strong robustness and excellent control performance with the dynamic error less than 10μm and static error near to zero. There are five major control parameters in this system, here, these parameters are optimized with genetic algorithm and the satisfied results are achieved. Furthermore, the method of PDFF is investigated, but its accuracy is less than that of above method.This thesis has completed the main design work of the linear servo system from the selections and installations of equipments to the design of control algorithms and the optimization of their parameters. After these work, we will continue to apply these algorithm to the experiment system and realize the design target of system.
Research of the Permanent Magnet Synchronous Motor AC Servo System Based on Direct Torque Control
Research of the Permanent Magnet Synchronous Motor AC Servo System Based on Direct Torque Control
Direct torque control (DTC) method is a new control strategy after vector control method. Permanent magnet synchronous motor (PMSM) driven by triphase sinusoidal current is research object in this paper. On the basis of analysis of the structure, movement principle and Ball Neodymium Magnets math model of PMSM, Fundamental theories and structure of the system of PMSM alternating current (AC) servo systems based on DTC are discussed. Then Simulation models of traditional PMSM DTC and PMSM DTC based on vectors subdivision are established separately. Compared with the traditional PMSM DTC, Simulation results show PMSM DTC based on vectors subdivision not only keep the advantage of quick torque response of traditional PMSM DTC but also reduce the electromagnetic torque ripples. At last, The controller hardware and software of PMSM AC http://www.chinamagnets.biz servo system based on the DSP (TMS320F2812) is designed . Experiment results prove that this control system is feasible and the three-loop control strategy can be realized. The performance of the designed AC servo system based on DTC can meet the needs of applications.
Direct torque control (DTC) method is a new control strategy after vector control method. Permanent magnet synchronous motor (PMSM) driven by triphase sinusoidal current is research object in this paper. On the basis of analysis of the structure, movement principle and Ball Neodymium Magnets math model of PMSM, Fundamental theories and structure of the system of PMSM alternating current (AC) servo systems based on DTC are discussed. Then Simulation models of traditional PMSM DTC and PMSM DTC based on vectors subdivision are established separately. Compared with the traditional PMSM DTC, Simulation results show PMSM DTC based on vectors subdivision not only keep the advantage of quick torque response of traditional PMSM DTC but also reduce the electromagnetic torque ripples. At last, The controller hardware and software of PMSM AC http://www.chinamagnets.biz servo system based on the DSP (TMS320F2812) is designed . Experiment results prove that this control system is feasible and the three-loop control strategy can be realized. The performance of the designed AC servo system based on DTC can meet the needs of applications.
Research on a PI Estimator with Parameters Updated in Direct Torque Control of Permanent Magnet Synchronous Motor
Research on a PI Estimator with Parameters Updated in Direct Torque Control of Permanent Magnet Synchronous Motor
In 1985, M.Depenbrock proposed the Direct Torque Control (DTC) method of asynchronous motor.DTC is very simple and has high control performance. After the successful application of DTC into servosystem of asynchronous motor, DTC has become one of the pop research point of AC servo systems. Butmost researches of DTC are focused on asynchronous motors and until recent years some researches areimplemented on the application of DTC into PMSM. For the research is still in its primary stage, manyquestions need to be solved. In this paper, the application of DTC into PMSM is discussed first, and thensimulation of PMSM DTC is implemented using MATLAB Block Neodymium magnets software. Influence of stator resistance variationon the performance of permanent magnet synchronous motor in direct torque control(DTC) system isanalyzed, followed by a technique for stator resistance estimation using a proportional-integral (PI) estimatorwith parameters updated, and is simulated through MATLAB
software. The simulation results demonstratethat this estimator is very effective in tracking the stator resistance, and is robust and has short response time,high accuracy. It is also seen that the compensator based on the PI estimator can overcome the probleminstability caused by a large mismatch between the stator resistance in control algorithm and the actual statorresistance. The foundation on the above method, another similar one is put forward. This scheme mainly http://www.999magnet.com usesa PI estimator which is based on the error between the actual torque and the estimated torque. It is seenthrough simulation results that the estimator may minish the influence of the stator resistance change, reducethe ripple of the flux and the torque, and improve the performance of the control system. At the end of thispaper, a DTC scheme based on flux error vector estimation (FEVE-DTC) was proposed to reduce torque andflux ripples. Model results shows that the torque and flux ripples were significantly reduced, currentdistortion is also reduced with a lower sample frequency compared that of basic DTC,So it is of superiorrunning performance.
In 1985, M.Depenbrock proposed the Direct Torque Control (DTC) method of asynchronous motor.DTC is very simple and has high control performance. After the successful application of DTC into servosystem of asynchronous motor, DTC has become one of the pop research point of AC servo systems. Butmost researches of DTC are focused on asynchronous motors and until recent years some researches areimplemented on the application of DTC into PMSM. For the research is still in its primary stage, manyquestions need to be solved. In this paper, the application of DTC into PMSM is discussed first, and thensimulation of PMSM DTC is implemented using MATLAB Block Neodymium magnets software. Influence of stator resistance variationon the performance of permanent magnet synchronous motor in direct torque control(DTC) system isanalyzed, followed by a technique for stator resistance estimation using a proportional-integral (PI) estimatorwith parameters updated, and is simulated through MATLAB
software. The simulation results demonstratethat this estimator is very effective in tracking the stator resistance, and is robust and has short response time,high accuracy. It is also seen that the compensator based on the PI estimator can overcome the probleminstability caused by a large mismatch between the stator resistance in control algorithm and the actual statorresistance. The foundation on the above method, another similar one is put forward. This scheme mainly http://www.999magnet.com usesa PI estimator which is based on the error between the actual torque and the estimated torque. It is seenthrough simulation results that the estimator may minish the influence of the stator resistance change, reducethe ripple of the flux and the torque, and improve the performance of the control system. At the end of thispaper, a DTC scheme based on flux error vector estimation (FEVE-DTC) was proposed to reduce torque andflux ripples. Model results shows that the torque and flux ripples were significantly reduced, currentdistortion is also reduced with a lower sample frequency compared that of basic DTC,So it is of superiorrunning performance.
The Research on Permanent Magnet Synchronous Generator Rectifing System
The Research on Permanent Magnet Synchronous Generator Rectifing System
As the means of the green environmental protection traffic, electric vehicle (EV) has been regarded by every developed countries. The EV technology is growing rapidly. The principal task is to research and design a PWM rectifier system used in Intergrated Starter/Alternator (ISA) system of hybrid electric vehicle (HEV).Firstly, this paper analyses the research status of HEV and ISA at home and abroad and the operating principle of Permanent Magnet Synchronous Alnico magnets Genetator with rectifing load. Secondly, the topological structure of the Permanent Magnet Synchronous Genetator is devised. And the feasibility of equivalent between the rectifier system with Permanent Magnet Synchronous Genetator and the three-phase voltage source rectifier (VSR) is confirmed.Subsequently, the design of the system parameters in main loop are analyzed in this paper. Specially we focused on the design of the
The DC-side capacitance and AC-side inductance.Besides,the specific parameters is proposed. Then the designing of regulators in double-loop VSR system are analyzed in detail. A modified PID control algorithm used in voltage loop is proposed, which guarantees both the response time and the overshoot. The results of system simulation with MATLAB/SIMULINK proved the advantage of the proposed algorithm and the validity of the parameter chosen. The results of http://www.999magnet.com experiment confirmed the validity of theory analysis too.Texas Instruments digital signal processor (DSP), TMS320F2407A, is used as the controller, and the full digital vector controlling system is achieved, which is used in the ISA of HEV for energy feedback. The controlling system can meet the requirement of subject improved by the experimental results, which manifest the adjustable of output voltage and current, the rapidity of the dynamic response, the high accuracy of controlling, the good stability and the high efficiency of the rectifier system.
As the means of the green environmental protection traffic, electric vehicle (EV) has been regarded by every developed countries. The EV technology is growing rapidly. The principal task is to research and design a PWM rectifier system used in Intergrated Starter/Alternator (ISA) system of hybrid electric vehicle (HEV).Firstly, this paper analyses the research status of HEV and ISA at home and abroad and the operating principle of Permanent Magnet Synchronous Alnico magnets Genetator with rectifing load. Secondly, the topological structure of the Permanent Magnet Synchronous Genetator is devised. And the feasibility of equivalent between the rectifier system with Permanent Magnet Synchronous Genetator and the three-phase voltage source rectifier (VSR) is confirmed.Subsequently, the design of the system parameters in main loop are analyzed in this paper. Specially we focused on the design of the
The DC-side capacitance and AC-side inductance.Besides,the specific parameters is proposed. Then the designing of regulators in double-loop VSR system are analyzed in detail. A modified PID control algorithm used in voltage loop is proposed, which guarantees both the response time and the overshoot. The results of system simulation with MATLAB/SIMULINK proved the advantage of the proposed algorithm and the validity of the parameter chosen. The results of http://www.999magnet.com experiment confirmed the validity of theory analysis too.Texas Instruments digital signal processor (DSP), TMS320F2407A, is used as the controller, and the full digital vector controlling system is achieved, which is used in the ISA of HEV for energy feedback. The controlling system can meet the requirement of subject improved by the experimental results, which manifest the adjustable of output voltage and current, the rapidity of the dynamic response, the high accuracy of controlling, the good stability and the high efficiency of the rectifier system.
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