Studies on Control Technology of Brushless DC Motor in Railway Switch

　　Studies on Control Technology of Brushless DC Motor in Railway Switch
　　The dissertation proposes control technology of rare earth permanent magnet brushless DC motor (BLDCM) in railway switch. Railway switch is one of important railway electrical signal devices. Generally, it is used to change the switch of railway tracks at cross ways and indicate the switch’s position.First, the dissertation summarizes the properties, developing state and application fields of BLDCM, then its fundmental structure; operation principle and Block neodymium magnet control strategy is also presented. On the base of roundly analyzing all kinds of the drive motor in electromotion type railway switch, BLDCM is proposed to replace the formerly traditional DC motor in railway switch. Second, the whole design scheme and key technology of control system is put forward based on analyse of the technical parameters and requirements. Then the whole system has been designed in detail according to five circuit function modules respectively: main power and drive circuit, PWM and logic synthesize circuit, forward & reverse auto recognize circuit, high-frequency DC/DC switching-mode power supply and protection against lightning strike of system. Finally, a prototype instrument is developed, the experiments of switching-mode power supply and BLDCM are accomplished and experimental results and its analysis are also presented.It can be seen from experimental results, that the control http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php system reaches all the qualities required by the railway point switch. The motor starts fast and operating well in forward and reverse working condition, at the same time, it has higher efficiency and has more powerful protections against electromagnetic interfere and lightning strike. The technology is used not only in the railway switch but also can be used in other drive control equipments and has extensive prospect.

Studies on Control Technology of Dual Redundancy Brushless DC Motor

　　Studies on Control Technology of Dual Redundancy Brushless DC Motor
　　This dissertation is based on the project —the research of servo controller for dual redundancy rear earth permanent brushless DC motor (BLDCM).The main focus is to develop the technology about servo control and fault-tolerant for dual redundancy BLDCM used in the aviation realm.Beginning with the dundamental properties of dual redundancy Ball Neodymium Magnets BLDCM, the mathematic model of dual redundancy BLDCM and servo system is established. It studies the rules of current、back electromotive force、speed and torque of dual redundancy BLDCM and simulates the servo system of dual redundancy BLDCM with triple-loops which includes position loop, speed loop and current loop in Matlab. Base on theoretical research, the triple-loops servo control circuit with DSP and CPLD of dual redundancy BLDCM is designed for electric actuation system, then the algorithm routine and strategy of redundancy management are proposed.After classifying different fault-types of servo system, this dissertation analyzes the performance of motor influenced by some main fault and presents the methods for motor fault detection and protection. Then, the concept、 selection、 http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php configuration and design of redundancy system are introduced and the redundancy management techniques such as fault protection, redundancy switch, and system rebuilt are discussed. At last , a current equalization method for dual-redundancy BLDCM is proposed for the problem of torque distributing disequilibrium by the influence of discrepancies in system parametersFinally, a prototype instrument is developed, the experimental work and the experimental results are accomplished. The achievements of the research have very important reference for continual research.

Research on Mixed-Excitation Electromagnetic Actuator and Its Control System

　　Research on Mixed-Excitation Electromagnetic Actuator and Its Control System
　　Electromagnetic actuators are widely applied in the fields of civilian and military industry, aviation and aerospace etc. With the development of application technology, electromagnetic actuator is required to be miniaturized, fast and high precise controlled, or to realize close-loop control with feedback of some parameters which users are interested in. For example, in the application of multi-fingered or apery robot hand, small size, high output force and fast precise position control are needed. For solenoid valves applied in fluid control field, it is necessary to realize proportional or servo control of press, flux or speed parameters. On this background, the investigation of mixed-excitation electromagnetic actuator and control system are put forward in the paper.Firstly, Neodymium Magnets the paper has reviewed the domestic and foreign development of electromagnetic actuator and its control techniques, and pointed out the problems and hot issues. The paper has discussed the related theory including the working characteristic of permanent magnetic, servo control techniques and techniques of electropneumatic proportional and servo valves. Then after the analysis of direct action solenoid valve with permanent magnetic and electromagnetic force, hydrokinetic force and resistance, the motion equation of the spool is deduced, and the proportional control is brought forward. Then a novel linear electromagnetic actuator system for position servo applications is described. The actuator is made of an NdFeB permanent magnetic moving part, which can return to equilibrium point and have hold force during the excitation power off, a stator with double excitation coils and two operating gaps. By changing the combination of the two electromagnetic excitations, the actuator can run in four quadrants of acceleration or http://www.999magnet.com/products/110-sintered-neodymium-magnets braking in duel direction. Changing the coil current can regulate the acceleration/deceleration and the hold force. Also the magnetic field distribution of the actuator is calculated using finite element analysis. Also the position control system of the actuator is developed. Its controller is based on a single chip processor with high accurate A/D converter to realize position information conversion. The electromagnetic excitation can be regulated by PWM driving module. The LED display and keyboard input modules are also

The Research of Coreless DC Motors for Traction Robot in Horizontal Well

　　The Research of Coreless DC Motors for Traction Robot in Horizontal Well
　　The control motors in the well traction robot require high temperature resistant, quick response, small volume and large power density. Because Coreless DC motors uses ironless-rotor, the inertia and inductance is very small, mechanical time constant is less than 28 milliseconds, several products can attain in less than 10 milliseconds. Its weight and size are 1/3 - 1/3 less when compared with an iron core motor of same power.Because Coreless DC motors’s structure is special, it’s difficult to manufacture, the research on the Coreless DC motors is very lack.With the neodymium prices use of rare-earth magnet and the application of finite element method (FEM) in the magnetic field analyse, the tradition design method of electric motor should be modification. A new design and optimization method was generated.According to the performance technical requirement and the key dimension relation, select the key dimension and outer magenet structure. The motor’s magnetic field is analyzed with finite element method (FEM) by ANSYS software. The EMF and electro-magnetic torque are calculated with path method base on the air gap magnetic flux density(B).The influence on the electromagnetic parameters, by the change of air ply, permanment magnet length and the magnetic pole arc http://www.999magnet.com/products/142-neodymium-prices coefficient, are calculated by the ANSYS software. The optimum parameter of the magnetic pole is obtained by solving the magnetic field.The vibration characteristic of the rotor is calculated by the ANSYS software. The first ten natural frequencies and mode shapes are calculated. The utmost velocity of the rotor can be calculated.

Study on Structure and Magnetic Properties of Rare Earth Transition Metal Intermetallic Compounds

　　Study on Structure and Magnetic Properties of Rare Earth Transition Metal Intermetallic Compounds
　　The new class of R(rare earth)-T(transition metal) intermetallics namely,R3(Fe,M)29 (R =Ce, Pr,Nd, Sm, Gd, Tb,Dy, Y; M =Ti,V,Cr,Mn,Mo,Nb,W ) are of current interest in the field of permanent magnet materials. Based on the study on R-T permanent-magnet material Nd3(Fe,Ti)29, this thesis deals with a study of the structural and magnetic properties as well as the the magnetocrystalline anisotropy. Below, the main experimental results and conclusions are summarized:1. A rare-earth-transition metal intermetallic compound is a candidate for excellent permanent Block Ceramic Magnets materials when it fulfills the following conditions: it must has a large spontaneous magnetization, a strong uniaxial magnetocrystalline anisotropy and a high magnetic ordering temperature . Since the R3(Fe,M)29 phase is an intermediate phase between the ThMn12 and Th2Zn17-type structures, production of the single R3(Fe,M)29 is difficulty and time consuming. For example,the Nd3(Fe,Ti)29 phase is usually produced by annealing of Nd–Fe–Ti alloy ingots at a high temperature of 1373K for a long period of 72–130h. The annealed Nd–Fe–Ti alloy still contains a small amount ofα-Fe phase.
　　We study the structure and magnetic properties of Nd–Fe–Ti alloy abtained by annealing of Nd–Fe–Ti ribbons produced by the melt-spinning technique. The XRD patterns and thermomagnetic curves show that the melt-spinning ribbons and the alloys annealed at a low temperature contain a large amount of Nd2(Fe,Ti)17 phase together withα-Fe phase. Substitution of Ti for Fe does not lead to a change of crystal structure, all alloys are in Th2Zn17-type structures. With increasing Ti content Curie temperature TC decrease monotonously . The Tc decrease from 503K to 483K for as-spun ribbons and 493K to 463K for 873K annealed alloys, respectively. Substitution of Ti for Fe may reduce the amount of magnetic ion, therefore the Tc decrease monotonously.2. In order to improve the intrinsic magnetic properties of Nd3(Fe,Ti)29 type compounds, such as saturation, magnetization, Curie temperature, and magnetocrystalline, anisotropy, in addition to formation of nitrides of these compounds, ion substitution is also an effective method. Recently some investigations of substitution of Co for Fe http://www.chinamagnets.biz/Ceramic/Block-Ceramic-Magnets.php have been carried out. It has been found that substitution of Co for Fe leads to a transition of magnetocrystalline anisotropy compounds. From basal plane to uniaxial in Gd3( Fe,Co) 25Cr4. In this thesis we study on substitution of Co for Fe in Nd3(Fe,Ti)29 alloys produced by melt-spinning technique.
　　XRD patterns and thermomagnetic curves show that the melt-spinning ribbons contain a large amount of Nd2(Fe,Ti)17 phase together withα-Fe phase. Substitution of Co for Fe does not lead to a change of crystal structure, all alloys are in Th2Zn17-type structures. It is worth noting that the saturation magnetization increases monotonically with Co concentra tion. But due to the smaller atomic radius of the Co atom compared wit Fe, TC of Nd3Fe27.6-xCoxTi1.4 compounds increases strongly with increasing Co content. It is 453K when x=0 and in increase to 675K when x=6.0.3. In order to find out the effect that Gd substitute Nd in Nd3(Fe, Ti)29 compound, we investigate the structure and magnetic properties of (Nd1-xGdx)Fe27.31Ti1.69 compounds by XRD and magnetic measurements. All compounds with x in the range of x≤0.6 crystallize in Nd3(Fe, Ti)29-type structure. Substitution of Gd for Nd leads to a contraction of unit-cell volume. That’s because the smaller atomic radius of the Gd atom compared wit Nd .The Curie temperature Tc of (Nd1-xGdx)Fe27.31Ti1.69 compounds increases monotonically with increasing Gd content. We think it’s due to the Gd-Gd exhange interaction. Saturation magnetization Ms and spin reorientation temperature Tsr of(Nd1-xGdx)Fe27.31 http://www.chinamagnets.biz/Ceramic/Block-Ceramic-Magnets.php  Ti1.69 compounds decrease with increasing Gd content. As temperature falls from room temperature to 5K, a spin reorientation from easy plane to the easy cone occurs for (Nd1-xGdx)Fe27.31Ti1.69 compounds.4. To find out the change of magnetocrystalline anisotropy for Er substitute Nd in Nd3(Fe, Ti)29 , (Nd1-xErx)Fe27.31Ti1.69 compounds were investigated by XRD and VSM and magnetic measurements. Substitution of Er for Nd does not lead to a change of crystal structure, All compounds with x in the range of x≤0.5 crystallize in Nd3(Fe, Ti)29-type structure. As temperature decreases from room temperature to 5K, a spin reorientation from easy plane to the easy cone occurs for (Nd1-xErx)Fe27.31Ti1.69 compounds.

Structure and Magnetic Properties of Co-Zr Alloys

　　Structure and Magnetic Properties of Co-Zr Alloys
　　Magnetic materials occupies important position in society in the nowadays , catch hitherto unknown attention right away once third generation rare earth permanent magnetism Nd-Fe-B appearing in the market,proprietor’s making joint efforts also makes development of Nd-Fe-B series permanent magnetism very swift and violent , very quick, and the function using latent energy one empty space to be enearth, changeable function difficulty continuing improving Nd-Fe-B , self contain abuse of rare earth easy to oxidize also being difficult to solve more well. People starts appearing that hopes in another one kind of much better permanent magnetic materials.Co-Zr base the Block neodymium magnet series alloy is beginning to study in 1964, the initial stage it is exceeded high anisotropy field above metal permanent magnetic materials, quickness quenches material having very good suppleness , this is that reality very suitable applies a characteristic of the Co-Zr base series alloy. People are discovered, Co-Zr base series alloy hard magnetism properties is controlled by Co5Zr phase , this one phase finds that on 1986 by Z.Altounian first in amorphous alloy, Co5Zr phase has fcc structure, space group F43m or F23 , crystal lattice constant a = 6.7A; ,Curie temperature Tc=500℃. Often, the existence has fcc Co phase, Co11Zr2 phase and Co23Zr6 phase in Co-Zr base alloy. in Nature fcc Co only stabilize existence in all above 425℃,
　　but it can be discover often all various smelting and quenching quickly in Co-Zr series alloy.Co11Zr2. Co11Zr2 phase has Pcna space group orthogonality crystal structure, crystal lattice constant a = 4.8A,b = 8.2A,c = 36A ,Curie temperature 490℃. Co23Zr6 phase has fcc structure,space group Fm3m, crystal lattice constant a=11.56A. A important condition having uniaxial anisotropy, being that magnetic materials is able to apply.We have studied the Co80+xZr20-x(0≤x≤4)alloy structure and magnetism properties:Co80+xZr20-x(0≤x≤4)smelting alloys have taking form rough crystal structure by arc stove. Most probably, smelting alloy middle mainly contains fcc Co phase, Co5Zr phase two kinds from the X-ray diffraction result having the broad diffraction peak, the broad diffraction peak is in a process changing each other being indicating a sample per se right away , http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php liquid state changes to fcc Co phase, Co5Zr phase from ebullition metal state, crystal particle being are rough by cooled speed effect. Sample has saturation magnetization 71 emu/g , as a result of Co5Zr phase existence. In the smelting sample, rough crystal particle of Co5Zr phasee also pointing out that we, exercise direct heat treatment of smelting sample may become acquisition the Co5Zr compound.Quench the technology progress quickly , make this one handicraft become important means for study of science and production. Speed of melt-spun, to Co80+xZr20-x(0≤x≤4) alloys quench the effect bringing structure and the function along slightly quickly very big.To Co80+xZr20-x(x=1、3、4) alloy, quickness quenches having dried as well as with 40 m/s speed , the Co84Zr16 alloy quickly quenches sample having being amorphism state very well, saturation magnetization intensity 61 emu/g , coercive force 90 Oe ,
　　magnetic moment per atom 1.10μB. Electric charge between Co atom 3d energy bands and Zr atom metastasis.Co80+xZr20-x(x=0、2) alloys with 25m/s speed melt-spun quickness quenches strip, manily have fcc Co and Co5Zr phase structure, have approximately 0.5 kOe coercive force, it totally different from alloys strip with 25m/s speed melt-spun quickness quenches. With the increase of Zr content x in the Co-Zr alloys, coercive force increase, saturation magnetization intensity increase, magnetic moment per atom increase, content of the Co5Zr phase also increases in melt-spun quickness quenches Co-Zr alloys. Therefore, continued changing the alloy component and melt-spun speed, be able to obtain Co5Zr compounds and more good magnetism properties , it opens up a road to clearer know characterof the Co5Zr compound.Heat treatment Co80+xZr20-x(x=1、3、4) alloys, that melt-spun with 40 m/s speed, the heat treatment temperature is 550℃, 650℃, 750℃, http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php heat treatment time is 2 hours. Sample after heat treatment, saturation magnetize intensity and magnetic moment per atom increase with the heat treatment temperature enhance. X-ray diffraction result of heat treatment Co81Zr19 quickness quenches strip point out that, fcc Co occupies main position, and a few Co23Zr6 phase, and with the heat treatment temperature increase, crystal spend gradually changeable completeness. Therefore, fcc Co appearing, is playing decisive role to the magnetism of quickness quenches alloys, crystal is spent gradually perfect, the crystal particle growth has produced effect also to magnetism. Electricity mirror result demonstrates , the strain of quickness quenches alloys has effect and inhibitory action to the crystal particle growth certain.In sum, we have known hard magnetism phase——Co5Zr phase can come true by two kinds approach in Co-Zr alloy, this have provided for this gaining the Co5Zr compound to facilitate. Various clear cognition Co5Zr compound physical property, further improve Co-Zr series alloy magnetism.

基于dsPIC的无刷直流电机控制器设计及齿槽转矩削弱方法研究

　　基于dsPIC的无刷直流电机控制器设计及齿槽转矩削弱方法研究
　　This thesis firstly explains the composing structure and operating principles of brushless DC motor and then discusses the relevant control strategies of it. The brushless DC motor (BLDCM) is set as the control target. The design of hardware of control system is conducted on the basis of dsPIC30F2010 microprocessor. And a digital processing Ball Neodymium Magnets is realized by the combination of digital signal processing with relevant circuit. The hardware system contains dsPIC external circuit, position detection circuit, bridge power drive circuit, protective circuit, etc. Software system which is compiled by C programming language contains main routine, service subroutine and interrupt subroutine. The main routine is used for initialization of slug and the variable, while service subroutine is used for A/D transition, software phase conversion, PWM production, and so on. The interrupt subroutine is triggered by Hall position signal.Based on the analytical method of energy approach and Fourier expansion, the analysis of cogging torque of permanent magnet motor equipped with parallel-magnetized surfaced mounted magnets has been conducted. A further study on several kinds of weakening methods of cogging torque has been made, including cogging torque weakened by choosing proper pole arc coefficient, by asymmetric distribution of permanent magnet, by combination of different polar arc coefficients, or by changing the shape of permanent magnet. Meanwhile, determination methods http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php of motor parameters in different ways of torque weakening are deducted. Finally, the results in different motor models are calculated and tested with finite element method, which proves the validity of the mentioned determination methods above.At last the 24V 500W BLDC prototype based on design intention is made. The prototype is then used for the experiment of control system designed in this thesis. It is proved by the experiment that the system is stable and efficient and the prototype runs well.

基于DSP的数字无刷直流电机调速系统的研究

　　基于DSP的数字无刷直流电机调速系统的研究
　　This paper describes a control system of sensorless permanent magnet brushless DC motor (BLDC) based on digital signal processor (DSP) after analyses and summarize the problem of the existing control system of sensorless permanent magnet BLDC, Based on study of the all the running method of sensorless permanent magnet BLDC, The principle and method of Back-EMF zero-crossing detection, phase judgement and phase-delay compensation are neodymium prices presented. The digital close-loop control technique is used to improve rotation speed characteristic wide scope of speed adjustment. This system used TMS320F2812, a DSP that made by TI, as the microprocessor. Thus it can easily output 6 PWM signals, Implement 12 bit A/D convertion, detect the position of rotor, compensate the phase-delay, switch smoothly between inner and outer synchronization and implement the speed close-loop control.The system is designed for the compressor of refrigeratory. On the view of the result of experiment, the motor started stably and quickly with small toque pulsant and http://www.999magnet.com/products/142-neodymium-prices had wide scope of speed adjustment. It can content all of the request of the compressor of refrigeratory. It also have the characteristic of simplicity, good adaptability and security, tc. So it would have wide scope of application.

Research on Similarity of Brushless DC Linear Motor

　　Research on Similarity of Brushless DC Linear Motor
　　The research on similarity of a series of motors which have a similar structure and different sizes is to seek for the intrinsic relationship and laws from their structure and characteristic. The application of these laws has great referenced worthiness for motor design, such as shortening period of design, reducing cost of examination. Based on the combination approach of analysis method and finite element simulation, This paper has researched the similarity of structure and thrust characteristic of Brushless D.C. Linear Motor (BLDCLM).Firstly, the cogging force similarity of BLDCLM is analyzed by the way of analysis method. And based on expounding variety approaches Neodymium Magnets for slot effect, this paper uses area function and monopole function to set up model for slot effect from the thrust fluctuation perspective, and then the cogging force ratio expression of two motors which have similar structure and different sizes is educed based on the detailed analysis of this model. What is more, this expression provides theoretical bases for analyzing Permanent Magnetic Linear Motor similarity.Secondly, this paper builds two finite element simulation models of BLDCLM, and then alveolus ratio, slot coefficient and pole embrace coefficient which are three influencing cogging force factors are respectively simulated by Ansoft software. Based on the simulation result, the similarity law of respective factor which has influenced cogging force and thrust characteristic is analyzed. Pole embrace coefficient which influences cogging force is analyzed by Fourier Series. The method of impairing cogging http://www.999magnet.com/products/110-sintered-neodymium-magnets force, from the aspect of choosing proper pole embrace coefficient, is educed by analyzing effect of pole embrace coefficient to fourier decomposition coefficient.Finally, the combination of field with circuit is feasible to analyze the structure similarity of BLDCLM. The ratio expression of yoke thickness to polar distance is educed, and this ratio range is also gained by finite element simulation, which provides referenced bases for analyzing the structure similarity of Permanent Magnet Linear Motor. The performance parameters of motors of different types and different volumes get a fluctuation within a certain range on

Study on Eddy Current in Discal Magnetic Driver

　　Study on Eddy Current in Discal Magnetic Driver
　　According as the basal theory of modern magnetism ,the magnetic driving is a new technology which realizes the contactless transfer of force or torque (power) by the magnetic force function produced through permanent magnet material or electromagnet .The equipment which can achieve the technology is named magnetic driver or magnetic transmission device, magnetic coupling and so on . With the magnetic driver in the industrial application of the gradual promotion, people driver to improve its efficiency with higher requirements. Scientific computing and control the eddy current in the magnetic driver, can effectively improve the transmission efficiency of the magnetic driver .Block Ceramic Magnets The essential different between the magnetic driving and mechanical driving is that magnetic force driving transfer the torque using the thin wall of distance sleeve or the working clearance produced while magnetic field permeate magnetic circuit when it transfer torque and force to driving parts .For example the magnetic force driving pump and stirred autoclave are taken the seal gland driven by magnetic force instead of traditional shaft contacted kinematical seal equipment adopted by mechanical pump and kettle .At the same time it change kinematical seal to static seal.So the leak produced in the sealed place of transmission shaft is eliminated radically and the problems such as spill ,emiting ,dripping ,leak and the heat and abrasion of mechanical seal being in the equipments like industrial pump and kettle are solved . http://www.chinamagnets.biz/Ceramic/Block-Ceramic-Magnets.php   All of these create qualifications for transportation safely or the agitation of mediums like being poisonous in reaction ,flammable ,easy-explosive,corrodent and valuable .Now the main problems existed in the technology of magnetic force driving are the lifetime of bearing ,
　　vortex ,high temperature and monitoring .The issue of vortex on magnetic driver has been investigated by many scholar but there are few people research on discal magnetic driver which is being vortex analysis in the paper .Discal magnetic driver is composed of inside and outside magnetic rotor and distance sleeve .Both the inside and outside magnetic rotor are made up of permanent magnet which is axial-magnetization and has been charged magnetism in opposite directions .The permanent magnet is arrayed alternately along the circumference in term of different polarities and fixed on yoke iron of mild steel to form siamesed magnetic open circuit .The distance sleeve is an important part of magnetic seal gland .If it is made of metallic material ,the metallic distance sleeve is in the alternating magnetic field whose direction and size change as specifically rule quickly when the inside and outside magnetic rotor do isochronous whirligig .In other words ,the flux in the thin wall of distance sleeve changes as time ,which will produce eddy current changed along the flux , current ring .The eddy current can heat permanent magnet and result in part irreversible demagnetization .So it is necessary to analyse the eddy current of magnetic force driver .The eddy current in the distance sleeve is arosen by the variational magnetic field ,so the research on the distributing and rule of magnetic field in the distance sleeve is the precondition to the study on the problem of eddy current in magnetic force driver .The basal theory of electromagnetic field is the springboard of this paper .Firstly ,the magnetic field of disk magnetic force driver is analysed by the numbers using the analytic method and finit element method .Then the farther analysis of the problem on the eddy current in the distance sleeve is done after getting the correct conclusion.The detailed content is as follows :(First).The theory of magnetic phenomenon is researched based on mass literatures of magnetism and magnetic force driving .The ultimate principle and character of the technology on magnetic force driving are introduced concisely .The developed history and actuality ,the key and developed orientation of the technology on magnetic force driving and the character of magnetic driver are analysed in a round .(Second). Firstly ,the structure and working mechanism of the magnetic driver are expatiated .
　　Then the vocabulary of terms often used in magnetic driver are introduced .At last ,the problem of eddy current being attention to the research on magnetic driver is discussed amply .All of these become the theoretical basis in the research on the eddy current of the discal magnetic driver .(Third).Two equivalent models of permanent magnet ,namely ,equivalent electrical current model and equivalent magneticcharge model often used in the theoretical arithmetic of electromagnetic field are introduced amply.The formula of theoretical arithmetic on air-gap field of magnetic force driver is deduced applying on equivalent electrical current model and based on the model of disk magnetic force driver researched in the paper.Then the formula of theoretical arithmetic is solved in MATLAB and the influence on air-gap field caused by the parameters such as the thickness of magnetic rotor ,the radius of magnetic rotor ,the thickness of air-gap is analysed .The three-dimensional model in finite element of the magnetic field of the discal magnetic driver is created by the soft of the finite element and the arithmetic solution of air-gap field is solved .The correctness of the formula of theoretical arithmetic built in the paper is proved when the results of finite element and theory are contrasted in a suitable bound .Then the validity in the formula of theoretical arithmetic in the distributing of eddy current is ensured .(Four).Firstly the formulas of arithmetic in eddy current often used in projects are introduced in list,which supply theoretical bases for the analysis and controlling of the eddy current in the distance sleeve of discal magnetic driver .
　　Then the formulas of theoretical arithmetic of the density distribution of the eddy current in the distance sleeve of discal magnetic driver with twelve magnetic poles is deduced based on the MAXWELL equation set of electromagnetic field and the formulas of http://www.chinamagnets.biz/Ceramic/Block-Ceramic-Magnets.php arithmetic about the spoilage of the eddy current is obtained .After that ,the formulas of arithmetic is solved by MATLAB and the influence on the spoilage of the eddy current caused by the structural parameters of the magnetic driver is analysed .At last the planar model in finite element of the eddy current is created in the soft of the finite element aiming at the character of the discal magnetic driver and the influences on the distribution of the eddy current caused by the parameters of the distance sleeve such as the electric conductivity, magnetic conductivity and the rotate speed relativing to the magnetic rotor are analysed.The formula and result of theoretical arithmetic in the paper are proved to be right when the results in finite element and theoretical arithmetic are compared under six different speeds .The steps on reducing the spoilage of the eddy current in the distance sleeve is analysed aiming at the solved results.These supply theoretical help for the controlling on the spoilage of the eddy current and increase on the transmission efficiency of magnetic force. This paper analyses show that:reducing the pole radius, increasing material strength of isolation sets, reducing the materials conductivity and magnetic conductivity of isolation sets neither is impact the effective amplitude of the axial magnetic field of the magnetic driver and effectively reduce eddy current losses ,these works has a very important significance for the control eddy current losses of magnetic driver and increase the transmission efficiency of the driver in the future.

超导磁力轴承悬浮力的有限元分析

　　超导磁力轴承悬浮力的有限元分析
　　A high temperature superconducting magnetic bearing, constructed by high temperature superconductors and permanent magnetic material, is a new kind of bearing, which is untouched between it’s stators and rotors. Since it is a stable system and doesn’t need controllers, so the high-temperature superconducting magnetic bearing is used in some rotating Block neodymium magnet machinery.Based on the electromagnetic field theory and the critical state model of high-temperature superconductor material, an analysis system for the high-temperature superconducting bearings using VB language on commercial FEM soft ANSYS, is developed in this paper. The static characteristics of the high temperature superconducting bearing are analysed and the flux density vector, magnetic field intensity and levitation force are obtained. The effect of bearing’s type and bearing’s structure parameters on the characteristics of the high temperature superconducting bearings is discussed.Levitation force is a function of distance between permanent magnet and superconductor, which is related with the bearing’s construction. For a thrust superconducting magnetic bearing, the levitation force is the largest when http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php permanent magnet’s diameter or width approximates superconductor’s diameter. For a radial superconducting magnetic bearing, axial levitation force is correlative to superconductor’s axial displacement and radial levitation force is correlative to the radial displacement between the stator and the rotator. Results show that at the same distance between permanent magnet and superconductor, the levitation force is larger when the permanent magnet is approaching to superconductor than that when the permanent magnet is leaving superconductor.

Recurrent Fuzzy Neural Network Variable Structure Position Controller Based on Vector Control of PMLSM

　　Recurrent Fuzzy Neural Network Variable Structure Position Controller Based on Vector Control of PMLSM
　　Position control of permanent magnet linear synchronous motor (PMLSM) is realized by MATLAB/SIMULINK software in this thesis. Based on the mathematics model of PMLSM which is analyzed in chapter 2, the simulation model of vector control system with SVPWM is built up, and the simulation results show that it has fast dynamic response and easy to realize, but has the disadvantages of big ripples of both thrust and current, and less robustness Ball Neodymium Magnets when external load disturbances exist.In order to reduce the ripples, and improve robust performance, variable structure control which belongs to modern control strategy is introduced. A variable structure adaptive (VSA) position controller is adopted, where a simple adaptive algorithm is utilized to estimate the uncertainty bounds. The simulation results demonstrate that its dynamic response and position track performance are greatly improved, and they have much smaller thrust and current ripples. With the external disturbance, position error and speed perturbation are apparently reduced, and the system is robust to parameter variations. However, the convergence rate of adaptive http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php mechanism is quite slow, it can not deal with the external disturbance effectively.To compensate the disadvantages, the combination of variable structure and intelligent control is expected. By means of the nonlinear adaptive and learning ability of fuzzy neural network (FNN), a recurrent fuzzy neural network (RFNN) variable structure position controller is investigated, in which the RFNN is utilized to estimate the real-time lumped uncertainty. Comparing with the VSA controller, RFNN has nearly zero thrust and current ripples, less position error and no speed perturbation, the rate of estimation convergence is further improved, and the chattering is reduced. It is proved that RFNN has high dynamic characteristics and is robust to parameter variations and external disturbance.

The Study of PMSM Servo Control System Based on TMS320F2812

　　The Study of PMSM Servo Control System Based on TMS320F2812
　　AC permanent magnet synchronous motor (PMSM) has the advantages of small inertia, small time constant, large torque, greater power per unit volume, and is very suitable for being implementation motor of AC servo control system. Therefore, the theoretical and applied research of PMSM servo control system has become the focus of AC servo control field. This paper investigates vector control, current closed-loop and speed closed-loop control of PMSM servo control Neodymium Magnets system using TMS320F2812 DSP as the core controller,which is manufactured by TI corporation and special for motor control. The main research works are as follows:The mathematical model of PMSM in two-phase synchronous rotating coordinate system is presented based on Clark and Park transform. PMSM vector control technique is described, and then this paper gives profound analysis of the principle of the PMSM servo control system using specific vector control with id = 0and space vector pulse width modulation (SVPWM) technique, which applies current closed-loop control and speed closed-loop control. In addition, the principle and realization of SVPWM, rotor position and speed measurement using optical encoder is discussed.The simulation model of PMSM servo control system is http://www.999magnet.com/products/110-sintered-neodymium-magnets established using Matlab/Simulink, to which SVPWM simulation module is critical. Simulation experiments are implemented, and the simulation waveforms of current, speed and torque of electromagnetic verify the correctness of the control system.The control system software module’s data and functions are packaged reasonably using C structure data type. Then, PMSM servo control system’s object-oriented software is realized based on TMS320F2812 DSP, which simplifies organization, debugging and expansion of the software, and offers a convenient software platform.PMSM servo control system software is debugged on the hardware platform, and related experiments are done. The results and problems are discussed and analyzed. All of these lay the necessary foundation for the follow-up study.

Research on Sensorless Control System of the Low Speed and High Torque PMSM

　　Research on Sensorless Control System of the Low Speed and High Torque PMSM
　　This paper select the typical application example in the low speed and high torque drive system—gearless elevator traction machine drive system. On the background of this system, the low speed and high torque PMSM was took as the research object, this paper has researched and accomplished the sensorless vector control of the low-speed and high-torque PMSM. The control system is supplied with spatial vector pulse width modifying (SVPWM) inverter can directly drive elevator without decelerator. This direct drive of elevator has not only simplified the construction of transmission neodymium standard state mechanism which improved transmit power density and efficiency of the drive system, but also increased precision and reliability of the control system.Firstly, the sensing method of the rotor position of PMSM is analyzed in detail. After that, an estimated method based on SMO is designed which has a strong robustness, simple control algorithm and easy, implementation of engineering application.Secondly, on the basis of analyzing the mathematical model and vector control principle of PMSM, the system model of the sensorless control of PMSM based on SMO is established, which provides a theoretical basis for carrying out simulation and experiment. This paper uses the simulation software http://www.999magnet.com/products/112-neodymium-standard-state MATLAB/Simulink to simulate the drive system of low speed and high torque PMSM and the results show that the system models are rightly built and control strategy is feasible.Finally, this paper choose TMS320LF2407 as the controller and composes the complete control software using assembly language, it realizes stator phrase current sampling, rotor speed/position observation and output of drive signal. On the design experimental platform, the sensorless control strategy was research. The result indicated the system performance meets the design requirements.

Study of the Four-Quadrant Control System of PMSM Based on DSP

　　Study of the Four-Quadrant Control System of PMSM Based on DSP
　　Permanent magnetic synchronous motor (PMSM) has the advantage such as the high power density and good operation performance; its adjustable speed drives (ASDs) control system has been applied widely in CNC, robot, aero, space, marine and other fields. However, the diode rectifier in the traditional ASDs control system has the inherent shortage of current cannot flow bi-directionally, producing harmonic pollution, and uncontrollable DC bus voltage, leading its restricted adopted in the industry.With the development of electronic and computer technology, the rectifier composed of fully controlled devices appears as the iceberg, and the PWM rectifier is most noticeable. Alnico Magnets The PWM rectifier has many advantages, such as the sinusoidal current input, controllable power factor, bi-directional current flow, controllable DC bus voltage, and the most important is its good performance in harmonic restriction and can act as an reactive-load compensation equipment. It covers the shortage of the diode rectifier, and is the inexorable trend of modern rectifier.As for the shortage of the traditional ASDs control system, replacing the diode rectifier with PWM Voltage Source Rectifier (PWM-VSR), this paper put up a new kind of four-quadrant control system of PMSM, with the hope to improve the power factor of the power grid and solve the four-quadrant operation of PMSM.
　　In the first part of this paper, the theoretical analysis of the four quadrant operation of the PMSM is discussed; and the emphasis have been put on the mechanism analysis of the energy regeneration when PMSM operated in quadrantⅡandⅣ, and the detailed quantitative analysis of the regenerated energy, which provides the theoretical support of the http://www.999magnet.com/products/108-alnico-magnets design of the four-quadrant control system of PMSM.In the second part of this paper, the hardware and software structure of the four-quadrant control system of PMSM have been designed. As for the hardware design, the emphases are put on the main circuit design and the synchronous circuit design. According to the properties of the power grid, this paper adapts the combination of the hardware and software to quantities the oriented angle. Using the TMS320F2812DSP as the core controller, the interface between the DSP and the main circuit is designed, realizing the controlling on the PWM-VSR system.In the last part of this paper, a test platform based on the TMS320F2812DSP is designed, bringing the four-quadrant operation of PMSM come true. And the simulation results and the experimental results show the designed control system can improve the current power factor of the power grid significantly, realizing the current flow bi-directionary with a high power factor.

Analysis and Calculation of the Magnetic Field of the Disc Coreless PMSM with Load

　　Analysis and Calculation of the Magnetic Field of the Disc Coreless PMSM with Load
　　Disk permanent magnet synchronous motor is a kind of permanent magnet motor, which is the high performance servo motor developing recently. It has many advances such as small volume, low weight, close structure, low moment of inertia of rotor, steady operation and so on. It has been made use of widely for military affairs, spaceflight, agriculture and daily life refered to rubber magnetic sheet as new drive device. Being one part of the national project 863“Design and integration technology of new rare PM motor”, the study object of this paper is the disk coreless PMSM based on Halbach array. Because of the coreless structure, the motor has less mass, lower loss and noise so that power is improved.Owing to the especial structure of the motor, the magnetic circuit of the disk coreless PMSM is different from the other common radial motors so that the former methods can’t be used to design this motor.In the paper, we build the 2D and 3D model of the armature and load magnetic field according to the structure of the motor. Then making use of the 2D and 3D finite element method to http://www.chinamagnets.biz/rubber/rubber-magnetic-sheet.php compute and analyze the magnetic field distributing with load. The influence of the armature magnetic field to the main field and the differences between the 2D and 3D FEM are discussed.Both the radial and axial magnetic field of the disk coreless PMSM are variational in that the motor belongs to the axial magnetic field motor. So some of the electromagnetic parameters are computed with the help of the FEM magnetic field numerical calculation. In the paper, some methods for the parameters calculation are introduced.The analysis of the armature reaction of the motor is an accessorial effect on the motor designation and improves the development of it. The disk coreless PMSM based on Halbach array could be used widely in many fields so that the motor was manufactured successfully could promote the development of interrelated product.

Auto Disturbance Rejection Control of PMSLM Based on Expanded State Observer

　　Auto Disturbance Rejection Control of PMSLM Based on Expanded State Observer
　　Direct thrust is produced and mechanical abrasion is reduced by linear motor without any conversion device.High gain and precise feed-forward are maintained by the system, the given processing path can be accurately tracked with high speed.However the system servo performance and precision machining are seriously affected when the motor internal parameters,end-effects and nonlinear factors are changed.
　　Therefore,adopting a reasonable and effective control Block Ceramic Magnets strategy to make linear motor "fast and stable" is an important thing in the industrial scene.Auto disturbance rejection control(ADRC) technique is a new type of digital control technique in which system model is not relied on,the algorithm in ADRC is simple,fast without overshoot,and the identification of accuracy is precise;the capabilities of tracking and anti-parameter disturbances are strong.Real-time estimation and compensation of system exterior and interior disturbances can be realized by ADRC with special nonlinear feedback structure to achieve good quality.In this thesis,ADRC is adopted to control permanent magnet synchronous linear motor(PMSLM) in order to harmonize the conflict issues between fast running and stability of PMSLM.Firstly,the mathematical model of permanent magnet synchronous linear motor is cleared.Secondly,theoretical foundation of auto disturbance rejection controller is researched,at the same time,the conception of "nonlinear" and "inverse control" http://www.chinamagnets.biz/Ceramic/Block-Ceramic-Magnets.php can be introduced to control PMSLM forwardly.Tracking-differentiator, expanded state observer and nonlinear state error feedback are analyzed deeply,the significance of internal nonlinear function and parameters are all understood strongly. Again,ADRC schematic diagram of PMSLM is constructed,auto disturbance rejection controller of excitation current and speed for PMSLM are designed,at the same time, torque current controller is also designed.Then,after simplifying the part of system structure,the various parameters are tuned dynamically based on the practical experience and theoretical analysis.Abrupt change of external disturbances and internal parameters change disturbances of PMSLM are recognized as a total disturbance,and then can be observed and compensated dynamically through expanded state observer.Finally,a specific PMSLM is simulated by MATLAB.The results of simulation test indicate that the anti-disturbance ability and robustness of PMSLM are strong while the speed of start-up is rapid and the stable performance is excellent.Thus,the control effectiveness and feasibility of ADRC are proved.

Simulation Comparison of DTC and SVPWM for PMSM

　　Simulation Comparison of DTC and SVPWM for PMSM
　　Permanent Magnet Synchronous Motor (PMSM) has characteristics of small volume, light, efficient, small inertia and reliability. It is widely used in servo , underwater propulsion. There were lots of papers about Direct Torque Control(DTC) and Space Vector Pulse Width Modulation (SVPWM) method to control the PMSM in the past, but there were few papers about the differences and advantages and disadvantages of the two technologies.Firstly, the paper Block neodymium magnet discusses general outline of speed control methods and control strategies of PMSM. The paper introduces the main developing directions of PMSM. The purpose and the main content of the project are given in this dissertation, too. Then according to the mathematical models of PMSM, paper analyses DTC and SVPWM control strategies ,which are advanced methods. The DTC gets rid of circumrotating coordinate conversion and decreases dependence of system on motor parameter. According to current and voltage of stator, to calculate amplitude of torque and flux linkage. So to reach the aims of direct control torque and flux linkage. By detecting the current , voltage and rotor’s angle. then through space coordinate conversion , we get expectation of stator flux linkage vector. Then we http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php modulate the expectation of stator flux linkage vector to control torque and rotation speed of motor. Using MATLAB/SIMULINK mathematic tool ,we construct the two models.Digital simulation technique always is useful tool in analysis and calculation of ac adjustable speed drive system. We use MATLAB/SIMULINK mathematic tool to simulate the two control strategies and obtain the torque, current, flux linkage ,etc curve. By comparing two systems, We can get the result——DTC system has excellent torque dynamic control characteristic but it also results in large ripples of torque , current and flux linkage. SVPWM system’s ripples of torque , current and flux linkage are smaller than DTC’s, but the control system is more complex.

Research and Realization of PMSM Vector Control System Based on TMS320F2812

　　Research and Realization of PMSM Vector Control System Based on TMS320F2812
　　Recently, with the development of high performance magnetic material,modern power electronic component and technology, control theory,furthermore, the special use MCU and simulation, it becomes possible inrecent years to make PMSM to be widely used. Thus, PMSM is a new type ofmotor involving in many subjects. Its advantages are high speed, highefficiency, high dynamic response, high temperature bearing capacity andreliability. It also has a long life and low noise characteristics than others. It iswidely applied to each domain, such as the computer system, householdappliances, Industrial production, Transportation vehicle, medical equipmentand so on. So it worth to studying and it also become hot topic.The DSP device depends upon DSP theory and algorithm to develop. It isused to dealing with different real digital signal’s processing. It be used in theVC Ball Neodymium Magnets system of PMSM to improve it Automation, precision and reliability,TMS320F2812 is newest CPU which is use for motor servo control systemuntil now. It basically satisfies the system request.The thesis is about Research and Realization of PMSM Vector ControlSystem Based on TMS320F2812.It realized fully digital-controlled and doubleclosed-loop control system.The thesis mainly discusses the vector control principle of PMSM, andthen gives the whole plan of the system, include the hardware circuit and thesoftware part .finally it gives the test results of the system. The full text isdivided into seven chapters altogether.
　　Chapter 1: This part introduces the background and meaning of thesubject research, related technology, main basic exchange frequencyconversion technology and its respective characteristic.Chapter 2: Introduce the basic principle of the vector control with PMSMand the necessary knowledge, mainly including the work principle of PMSM,Mathematical model base on d,q,0 Coordinate system, Coordinate conversionand the whole system, and emphatically introduced the SVPWM waveproduction principle.Chapter 3: Give the total project and the http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php hardware structure of the system.It include the TM320F2812 and its small system broad, Power drivemodule-DR15A and its interface circuit, Position examination circuit anMan-machine interactive part and so on ,it is the base of the whole system.Chapter 4: Give the software design of the system. First, it is the briefintroduction of CCS, and then it is relatively the detail of software system,which includes the SVPWM wave subprogram, the position subprogram, thecurrent collection subprogram, the Coordinate conversion subprogram and picontroller etc.Chapter 5: Introduce the Realization of PMSM Vector Control System in MATLAB/SIMULINK platform .Give the main program,other subprogramand its simulation result, and realized the pro and con speed adjusting ofPMSM,At the same time, through the simulation we have Deeper and morevivid comprehend about the vector control system of PMSM.It is helpful toreal system and makes me avoid some unnecessary trouble.Chapter 6: It is the experiment result .first is SVPWM waveform, thephase circuit waveform, speed controlling curve. And then analyze it withtheory. All of those test result prove the VC system of PMSM.Chapter 7: Summarize the full text. It summarizes the research work andachievement, analyzes the way to make improved, and gives the suggestion ofthe future work. The mainly achievements of the thesis includes the totaldesign of PMSM control system, the research of the key technique and therealization of system.

Simulation Comparison of DTC and SVPWM for PMSM

　　Simulation Comparison of DTC and SVPWM for PMSM
　　Permanent Magnet Synchronous Motor (PMSM) has characteristics of small volume, light, efficient, small inertia and reliability. It is widely used in servo , underwater propulsion. There were lots of papers about Direct Torque Control(DTC) and Space Vector Pulse Width Modulation (SVPWM) method to control the PMSM in the past, but there were few papers about the differences and advantages and disadvantages of the two technologies.Firstly, the paper Block neodymium magnet discusses general outline of speed control methods and control strategies of PMSM. The paper introduces the main developing directions of PMSM. The purpose and the main content of the project are given in this dissertation, too. Then according to the mathematical models of PMSM, paper analyses DTC and SVPWM control strategies ,which are advanced methods. The DTC gets rid of circumrotating coordinate conversion and decreases dependence of system on motor parameter. According to current and voltage of stator, to calculate amplitude of torque and flux linkage. So to reach the aims of direct control torque and flux linkage. By detecting the current , voltage and rotor’s angle. then through space coordinate conversion , we get expectation of stator flux linkage vector. Then we modulate the expectation of stator flux linkage vector to control torque and rotation speed of motor. http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php Using MATLAB/SIMULINK mathematic tool ,we construct the two models.Digital simulation technique always is useful tool in analysis and calculation of ac adjustable speed drive system. We use MATLAB/SIMULINK mathematic tool to simulate the two control strategies and obtain the torque, current, flux linkage ,etc curve. By comparing two systems, We can get the result——DTC system has excellent torque dynamic control characteristic but it also results in large ripples of torque , current and flux linkage. SVPWM system’s ripples of torque , current and flux linkage are smaller than DTC’s, but the control system is more complex.

The Research and Development of the Speed Regulating System of Automotive Air-condition Fan

　　The Research and Development of the Speed Regulating System of Automotive Air-condition Fan
　　With the development of the technology and the improvement of the people’s life level, people have more requirement to the comfort of automobile. Therefore, many kinds of automotive air-conditions system come out rapidly. The speed regulating system of the air-condition fan influences the air-condition system’s performance of adjusting the temperature in a large extent. The engineer all over the world are studying the better speed regulating system of air-condition fan.According to the change of the environment’s temperature and people’s different requirements to the automotive inner temperature, comfort and saving power, it is necessary for air-condition fan regulating the speed in all kinds of situations in order that it can adjust the exchange ratio of the inner rubber magnetic sheet air temperature and wind speed of the exit of air-condition fan, thereupon, the different requirements of passengers are satisfied, consequently, it is necessary for air-condition fan to regulate speed, and then it appears many varieties of the speed regulating system of air-condition fan.DC motor has the high running efficiency and benign performance of speed regulating, therefore, the early speed regulating systems of automotive air-condition fan mostly adopt DC motor to regulate the speed. DC motor adopt the brush to change direction, so the reliability and life-span of the system is being reduced, in the mean time, it can lead strong electromagnetic interference, as a result of that, the other electrical system of the automobile and environment can also be influenced.With the maturity of the technology of the AC frequency conversion, asynchronous motor speed regulating system has a extensive application in each industrial field.
　　This kind of speed regulating system has the merits such as simple framework, credibility of working, without mechanical abrasion and less electromagnetic interference, thereby, it gradually replace the DC motor speed regulating system. On the other hand, the power factor of the asynchronous motor is low, so it faces the trend that it will be replaced by the brushless DC motor speed regulating system whose performance is much better than former system.At present, research personnel put more energy on the study on the permanent brushless DC motor speed regulating system of air-condition fan, in order that the speed regulating system of automotive air-condition whose performance is better than before face to the world as early as possible. Permanent brushless DC motor can be divided into two kinds. The one has position sensor, the other has not position sensor, it is called sensorless one. The research on the latter one is hotspot.The detecting system of position sensorless does not need mechanical position sensor. At the present time, the research core and key on position sensorless brushless DC motor controlling is detecting circuitry of the framework rotor position signal. The rotor position signal can be gained from software and hardware credibly, and then touch off the corresponding power apparatus, later, the motor run.Recent years, there appears a lot of the method of detecting rotor position worldwide. There are several kinds in general below: the method of inverted-electromotive force,the method of using inductance, the method of state observer,the method of vortex, the method of Kalman filter, the method of estimating magnetic chain.
　　The aim of this dissertation is the study on the speed regulating system of automotive air-condition fan, the content and conclusion is below:1.Introduce the developing status quo of speed regulating system of automotive air-condition fan, analyze the merits http://www.chinamagnets.biz/rubber/rubber-magnetic-sheet.php and defects of three kings of speed regulating system of automotive air-condition fan, indicate the research significance and content of dissertation.2.Analyze the base framework and working theory of brushless DC motor, demonstrate the rotor position detecting and switch circuitry case of brushless DC motor. This article adopt a newly detecting method to achieve the rotor position detecting, it is called the method of G (θ) function. The result proves that this method is a effective one.3.Analyze the working theory and feature of the PID control system, introduce the theory and composing of the fuzzy control and double fuzzy control specially and feasibility and advantage of using former theory in the speed regulating system of air-condition fan. Finally, choose the method of fuzzy PID control to apply to the speed regulating system of air-condition fan control.4.Setup the mathematic model and simulating model of speed regulating, analyze by simulating, evaluate the control strategy. Through comparing with the double PI adjusting simulation, the advantage of the fuzzy PI control strategy is obvious. Fuzzy PI control strategy has benign steady precision , less steady error and strong ability of countering the http://www.chinamagnets.biz/rubber/rubber-magnetic-sheet.php interference. Thereby, with the development of modern control technology, fuzzy PI control will apply in variety of speed regulating in a large extent.5.Finish the software design of speed regulating system of automotive air-condition fan. As the limit of condition, this article does not finish the hardware design of the system, this is the main direction of next step work.Position sensorless permanent brushless DC motor speed regulating system of automotive air-condition fan will realize in the late future, produce in many batches and apply in the real car. The study on this system will promote the development of the motor controlling, and naissance more applied method of detecting.

微型电动汽车驱动控制系统研究

　　微型电动汽车驱动控制系统研究
　　To reduce energy consumption and decrease the hazardous tail pipe emission, significant efforts have been accumulated globally to push the Electric Vehicle (EV) and Hybrid Electric Vehicle (HEV) program into mass-production stages. Consequently, it is expected that the internal combustion engine powered vehicles will eventually be replaced Block Ceramic Magnets by electric ones.The thesis is focused on the study of the permanent magnet brushless DC motor (BLDCM) drive with application to Electrical Vehicles. The main work is the design of a high performance control system based on a TMS320LF2407 DSP.Firstly, based on the comprehensive review of the characteristics and control methods of BLDCM, the operating states and control strategies of a BLDCM with applications in EV are proposed with respect to Power electronics, Electronic technology, Micro Electric technology, special integrated chips and the theory of Motor control theory.The velocity closed-loop control system for a BLDCM based on DSP TMS320F2407 is then designed. Thirdly, the performances of the control system are numerically studied by using Simulink. Finally, the designed control http://www.chinamagnets.biz/Ceramic/Block-Ceramic-Magnets.php system is experimentally investigated on a prototype motor. Both numerical and experiment results show good agreements with each other, which positively confirms the feasibility and practicability of the proposed control system.

注射成型粘结稀土永磁体的研制

　　注射成型粘结稀土永磁体的研制
　　This article discusses in the foundation of the injection rare earth permanentmagnet compounded lnaterials, and pointing out main problems which exists in thedevelopment and the production areas. The rare earth magnetic powder’s surface,composition for rare earth bond magnet, and property of the injection rare earth permanentmagnet compounded materials were studied. Furthermore, the relationship between theflow of the injection and the property of the materials was discussed.The surface properties of rare earth magnetic powder and polymer resin areentirely different, so their compatibility is very bad. In order to get two unions togetherwell, their compatibility must be changed firstly. The surface impact between the rareearth magnetic powders and the polymer resin was weak, and the dispersity of themagnetic powders in resin was bad when the content of the Block neodymium magnet rare earth magnetic powderswere in high fills. How to improve the rare earth magnetic powder’s dispersivity inpolymer, and how to enhance the surface contact, were studied in the paper. The use ofdifferent types of the coupling could improve the rare earth magnetic powder’s surface,and enhance the compatibility between the magnetic powder and the polymer. Theresults of experiment indicated that under the suitable dosage and the flow condition,use of the KH-550 coupling could modify the magnetic powder’s surface, enhancecompatibility between the rare earth magnetic powder and the polymer substrate, andimprove the dispersity of magnetic powder in polymer, so the compound materialdisplayed high longitudinal strength and high elongation ratio. Simultaneously, theresults of experiment showed that the KH-550 coupling could also improve the anti-oxidized ability of the magnetic powder under high temperature.In order to obtain high magnetism performance product, the content of magneticpowder in compound materials was very high; meanwhile, the mixture of grains waschanged to be difficult, and the dispersity of the magnetic powder was changed to bebad. If the fluidity of the injection was bad, the appearance of the product would berough, brittle, and very difficult to satisfy the actual application.
　　In order to improve thefluidity of the melting-body in full filling condition, different types of lubricant function were used in the paper. Though the metallic soap might enhance the fluidity of themelting-body, the dosage was huge, which might cause drops on the mechanics intensityof the product, and cause magnet to be crisp and easy to crack. EBS might enhance http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php thefluidity on melting-body and keep mechanic intensity of the compound materials to behigh. EBO could not only enhance the fluidity of melting-body, but also enhance themechanic intensity of the compound materials。In order to acquire different properties of the rare earth magnet, the relationshipbetween the content of magnetic powders and properties of the compound materials wasstudied. The magnetic property of the compound materials would be high if thecontent of the powders is high. While, high content of the magnet powders may causethe fluidity to become bad and hard to forming and process, and the mechanic intensityto drop sharply. When the neodymium iron boron (NdFeB) magnetic powder content is94 wt %, or the samarium cobalt (SmCo) magnetic powder content is 95 wt %, idealinjection bond magnets might be obtained.In conclusion, the influence of the flow condition to the magnetism performance,and emphases of the injection flow condition to the aeolotropism samarium cobaltmagnet were studied in the paper. In order to obtain the injection samarium cobaltmagnets with high performance, high injection temperature, mould temperate andquickly injection speed must be needed.

Research and Implementation of Doubly Salient Electro-magnet Starter-Generator System

　　Research and Implementation of Doubly Salient Electro-magnet Starter-Generator System
　　Doubly Salient Electro-magnet Machine is a new type Machine that derived from Doubly Salient Permanent-magnet Machine, it inherited the advantages of simple structure, high reliability and being fit to high speed operation from DSPM.In the mean time, the problems of voltage regulating and eliminating magnetism under fault state were solved owing to the advent of DSEM. At the present time, the engineering of 270V high voltage DC generator Ball Neodymium Magnets system using DSEM has appeared. In addition, DSEM has the characteristic of high torque-current ratio and good performance when it’s used as motor. So DSEM has become one of candidates applying to future starter-generator technology for aeronautics, study on forming starter-generator system based on DSEM is very necessary.This paper introduces the structure and magnetic characteristics of DSEM starter-generator firstly, and describes mathematic model and operation principle of DSEM starter-generator in succession, finally,the characteristics of DSEM starter-generator are summarized. These contents are foundation of following research.Experiment validation is important step of subject research, this paper establishes experiment platform of DSEM starter-generator system,this system constitutes of power converters and corresponding hardware and software based on DSP & CPLD.The work process of DSEM starter-generator system consists of starting process, starting-to-generating state conversion process and generating process, this paper establishes the simulation models using http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php MATLAB based on different work processes, and fulfills theoretical analysis and digital simulation of control methods under different work processes.
　　DSEM starter-generator system do exists different fault states during different work processes, include power converter faults and electric machine faults, theoretical analysis and digital simulation of fault states and partial experiment validation based on starting process is done in this paper. And results prove that DSEM starter-generator system has good fault-tolerance under certain fault states.This paper finally introduces the configuration of DSEM starter-generator experiment system and partial experiment results under different work processes, the experiment results prove the validity of design and feasibility of DSEM starter-generator system.

空压机用永磁电机控制系统的研发

　　空压机用永磁电机控制系统的研发
　　Reciprocating compressor plays an important role in the national economy for it’s advantages like wide-range use and so on. In our country, reciprocating compressor is mainly droved by asynchronous induction machine, which leads the fact that the efficiency is very low. At present ordinary Permanent Magnet Control system usually accept PI control arithmetic with the velocity and torque feedback equipment as its controller. However rubber magnetic sheet the price of this controller is still high comparing with the low-cost compressor, meanwhile air force in the compressor is varying according to the motor’s rotation, which means the load of the motor has periodical ripple. In this situation, the character that stability is in contradiction with response velocity of PI parameter integration method is obvious.
　　In some critical situation where sophisticated control is needed, the Permanent Magnet Synchronous Motor is usually used as the air compressor driver. However, the control is quite complicated and expensive. In order to solve this contradiction, a low-cost control especially for reciprocating compressor was proposed.In the dissertation, reciprocating compressor’s torque characteristics on the condition of single compression, double compression in the same pressure rate and double compression in different pressure rate were analyzed in detail from the viewpoint of compressor design. Research on optimizing the resistance characteristic of the compressor was done to facilitate the control development.Theories for Brushless DC Motor and the direct torque control of the Permanent Magnet Motor were presented. On the basis of the idea of direct torque control as reference, and took the reciprocating compressor’s torque into consideration, varying duty-cycle control method was put forward. Simulink toolbox and simulation programs written in MATLAB were used to http://www.chinamagnets.biz/rubber/rubber-magnetic-sheet.php verify the feasibility of this method.Torque ripple due to untimely phase conversion was analyzed in detail. Mathematical models for back-EMF current and torque ripple in untimely phase conversion were developed. An experimental circuit board was built for the proposed control system, including the rectification circuit, power driver circuit, back EMF detection circuit and so on. PIC programs were written to implement functions like phase conversion jump-start, back EMF detection and so on.A proper curve obtained through experiment, which represents the relation between voltage and frequency, was presented to guarantee that the motor could jump-start steadily. Experiment verified that capacitance, duty-cycle and frequency would affect the detection of back EMF; and that the varying duty-cycle control method is necessary and feasible, which provides a novel design way for the Brushless DC Motor used as compressor driver.

The Development of PMSM Servo Drive Controller

　　The Development of PMSM Servo Drive Controller
　　This project is consigned by GSK CNC Equipment Co., Ltd, in cooperation to develop the high-speed and high-precision machine tool servo drive controller. According to Computer Numerical Control (CNC) Machine Tool Feeding Control, using the sensored Field Oriented Control (FOC) and Feed-forward Compensation Control Theory, designs the Permanence Magnet Synchronous Motor (PMSM) servo drive controller base on the TMS320F2812 DSP controller.The mathematical model of the PMSM and the vector decoupling control neodymium standard state strategy are analyzed. Coordinates transform equation are given. Compare several realizations of vector control method, and id=0 method is chosen. Trandsducer control of servo motor driver based on SVPWM is realized.This system includes TI’s DSP-TMS320F2812 and TS5668M21 17-bit absolute encoder, that make a great improvement in Real-time processing capability and the Positioning accuracy. Design software system using modularization thinking. Following the principle of "functional independence" optimization program structure, System software modules are into Main program and vector control. Using the anti-windup PID controller and the with speed and acceleration feed forward position controller,increasing the steady and Positioning accuracy.This paper analyzed the Parameter setting of current loop, speed loop and position loop ,The proportion degree method is used in rectification the PI parameter. Its http://www.999magnet.com/products/112-neodymium-standard-state validity is verified in simulating experiment and it is reference for real system turning. In this paper the relationship of current with loss of permanent magnet synchronous motor is achieved by considering the copper loss and iron loss. and the control algorithm of current vector minimizing the electrical loss is proposed .Simulation result have shown that the proposed loss minimization control significantly minimizes the motor electrical losses and greatly improves the efficiency compared with the conventional control method.

Research on the DSP Based Sensorless PMSM Vector Control System

　　Research on the DSP Based Sensorless PMSM Vector Control System
　　The dissertation researches on the PMSM vector control system using Extended Kalman Filtering (EKF) algorithm. The main contents are as follows:Firstly, briefly introducing Coordinate transformation thought, PMSM Model in the static coordinate system and the revolving coordinate system and Vector Control principle. Based on the model, the sensorless PMSM vector control speed adjustment is discussed.Secondly, the thesis emphasizes the illustration of the principle of the EKF and it’s application in the system, deduced the EKF Alnico Magnets equations of PMSM in the static coordinate system and the revolving coordinate system. The control diagram is provided, and some optimized methods are proposed. The simulation model of the Vector Control system of PMSM based on the EKF is established and the application of the sensorless in motor control is successfully realized. The reasonability and validity of the EKF programmer in the motor control have been testified by the simulation results.Lastly, this paper uses the Motorola 56F8346 Digital Signal Processor (DSP) as the core of the motor control. The main structures of the software and handware are introduced. The http://www.999magnet.com/products/108-alnico-magnets main functional blocks are illustrated. To the hardware, each part of the control circuit and the design of the peripheral circuits are thoroughly discussed. The control software is being programmed with C. The flow charts of main program and PWM interrupt service routine are given.The program is being debugged in the IDE of Metrowerks Codewarrior so as to test the correctness of the system design.

Study on Low-Speed and High-Torque Gearless Drive System

　　Study on Low-Speed and High-Torque Gearless Drive System
　　Nowadays, permanent magnetic synchronous motors (PMSM) are used very widely in many industry fields, especially in elevators and high precision servo systems, because of their advanced performances beyond other motors. What’s more, Block neodymium magnet permanent magnet material-rare earth is very rich in our nation;therefore, doing research on the control system for PMSM has great science significance and application value.This paper introduces a novel gearless drive system of low-speed and high-torque (LSHT) PMSM for elevator. It that supplied with spatial vector pulse width modifying (SVPWM) inverter can directly drive elevator without decelerator. This direct drive of elevator has not only simplified the construction of transmission mechanism which improved transmit power density and efficiency of the drive system, but also increased precision and reliability of the control system. In this system, rotor position observation is innovative point which avoids a lot of questions caused by mechanic sensor.
　　On the theory, according to the mathematic model of PMSM, the paper presents and realizes i_d = 0 control strategy after analyzing the advantage and disadvantage of diversifiedcontrol strategies. Based on low-speed motor drive system, the design adopts a novel approach of rotor speed/position estimation based on adaptive control. Furthermore, it introduces http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php SVPWM technology in order to reduce harmony of the system. This paper uses the simulation software MATLAB/Simulink to simulate the drive system of low speed and high torque PMSM and the results show that the system models are rightly built and control strategy is feasible. On the basis of hardware TMS320LF2407 of PMSM control system, the paper composes the complete control software using assembly language and realizes stator phrase current sampling, phrase voltage calculation, rotor speed/position observation and output of drive signal. Finally, the inverter-motor model drive system of 1 lkW PMSM is successfully designed and the data of experiment verifies that the proposed vector control scheme is valid, and the dynamic and static performances are quite well. Furthermore, the propose strategy has stronger robustness.

The Research on Control System of Sensorless PMSM

　　The Research on Control System of Sensorless PMSM
　　Permanent magnet synchronous motor (PMSM) have no exciting current in the rotor, and are of high efficiency and power density. But motion control of permanent magnet synchronous motors requires accurate position and velocity signals to accomplish field orientation. In conventional motion control systems, optical encoders or rotary transformer Ball Neodymium Magnets are used for these purposes. However, these additional sensors increase the costs of the system and reduce the reliability. With this background, the research based on the abolishment of these sensors to increase the reliability and decrease the costs is becoming popular.International Rectifier Co. offers a new controller family referenced IRMCF341, which is specifically designed for the needs of sensorless digital motor control. In a single chip application, this device combines a fixed point core with micro-controller peripherals, which combines high-speed signal processing and the ability to optimize motor control peripheral integrated circuits, drive control can provide a reliable and efficient high-performance signal processing and control.On the basis of the summary for the development and application of PMSM motor http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php speed-variable system, this dissertation introduces a control system, which uses IRMCF341 to control the commutation and speed of PMSM. The basic structure, operational principle and design method of this system are set forth in this dissertation. The thought of hardware design and software programming is introduced as well. At last, the experimental results presented are reasonable, feasible,so that the effect of motor control is well.

Electromagnetic Field Analysis of a DSPM Based on Finite Element Method

　　Electromagnetic Field Analysis of a DSPM Based on Finite Element Method
　　The Doubly Salient Permanent Magnet Motor (DSPM) is a new kind of AC variable-speed drives motor,it was introduced in 1990s with the developing of power-electronics and micro-electronics.Recently, more ana mor attention and research having been paid to this motor because of its advantages,such as simple structure,flexible control,quick response,high reliability, high efficiency, etc. At present, in our country and oversea , the research on DSPM is mainly focuses on two directions: one is the basic theory of the DSPM, another is control system neodymium standard state development.On the base of reviewing the development history of DSPM motor, introducing its research situation in our country and overseas,understanding its components, A novel 12/8-pole stator located PM motor is designed according to DSPM theory, in this paper, The main contents are as follows:At first,the paper briefly introduces the fundamental structure, operation principle and mathematical model of the DSPM motor; secondly,the static-state characteristics of the model DSPM are analyzed based on two-dimensional (2D) whole field finite element analysis (FEA) in ANSYS, including flux linkage characteristic, inductance characteristic and torque characteristic,as a result the magnetic field distribution at http://www.999magnet.com/products/112-neodymium-standard-state different rotor positions is found; at last, the influence of air-gap on the DSPM’s static characteristics is analyzed in this paper, The calculation results show the airgap is great influence to the DSPM torque size and the torque ripple,And this offer an important theoretic underground for the research deeply and design of DSPM .

High-Order Sliding Mode Control of PM Synchronous Motor

　　High-Order Sliding Mode Control of PM Synchronous Motor
　　Permanent Magnet Synchronous Motor (PMSM) has been widely used in aerospace, numerical control machine, robots and so on, due to its desirable features of compact structure, high torque/inertia ratio and low power losses. However, PMSM is a multivariable, strong coupling and nonlinear system, suffering from plant parameters variations and load disturbances. In order to improve the performance of PMSM servo system, the research of control strategy is challenging.Sliding Mode Control (SMC), which is strongly robust to system parameters variations and external disturbances, has a desirable perspective in PMSM control field. To eliminate Neodymium Magnets chattering phenomena in SMC, this paper firstly studies a kind of High Order Slding Mode (HOSM) control method for nonlinear systems. By designing the nonsingular terminal sliding mode functions, robust differentiation estimator and corresponding control algorithm, the chattering-free HOSM control of system is realized. Then, integrating with vector control technique, double loop HOSM control of PMSM speed/position servo system is achieved. Meanwhile, sensorless vector control technique for PMSM is studied and an improved estimation method of rotor position/speed based on sliding mode observer is proposed. Finally, a load torque estimation method is proposed for speed controller and the problem http://www.999magnet.com/products/110-sintered-neodymium-magnets of robust control for systems with unknown load disturbances is sovled. For the current cotroller, an adaptive compensation strategy is designed to compensate the nonlinear disturbances of PWM inverter.The simulation results indicate that, the proposed control method in this paper is correct. The designed HOSM controller for PMSM system can eliminate chattering and guarantee the robustness. The improved sliding mode observer can enhance the estimation precision for rotor position/speed. The adaptive HOSM controller against nonlinear disturbances can improve the performance of motor control.

Structural and Magnetic Study of Melt-spun CeCo5 Ribbons

　　Structural and Magnetic Study of Melt-spun CeCo5 Ribbons
　　RCo5 (R = Y, Ce, Pr, Sm)-type intermetallic compounds with CaCu5 structure have attracted considerable attention due to their large anisotropy fields HA, relatively high saturation magnetizations MS and high Curie temperatures TC. But only SmCo5 magnet has been widely used because there are some technical difficulties in fabrication of several other materials, and no easy access to high-coercivity requested by the fine micro-structure. Rapid quenching (melt-spun) possess controllable rapid cooling speed, which is easy to fabricate small and fine micro-structure. Rapied quenching (melt-spun) has been widely used in Bonded NdFeB Magnets fabrication also for its convenience and low energy consumption. Many researchers have fabricated melt-spun neodymium prices YCo5, PrCo5 and SmCo5 magnet, but the magnetic properties still could not satisfy the practical requirements. Recently, obvious grain orientation of melt-spun RCo5 has been reported, which makes use of melt-spun RCo5 anisotropic bonded magnets possible. CeCo5 posses similar inherent magnetic properties as SmCo5, especially that Ce is much cheaper than Sm in price due to its rich reseves, these make the study on anisotropic melt-spun CeCo5 permanent magnet so significant.In this work, melt-spun CeCo5 ribbons have been made, and the effect of ingredient and cooling speed on gain orientation and magnetic properties have been investigated. In addition, magnetic properties of ribbons have been improved by Cu and Fe doping and annealing treatment. At the same time, the magnetization reversal mechanism has also been discussed and analyzed. The main activities include as following:I. Structure and magnetic properties of CeCo5 binary alloy ribbons 1. melt-spun CeCo5.4 ribbonsR-rich phase has been found in arc-melt Ce-Co alloy with the ratio of 1:5 beside CeCo5 phase, which could be inhibited by increasing Co content, Ce-Co alloy with single CeCo5 phase has been obtained at the ratio of 1:5.4 finally.With surface velocities http://www.999magnet.com/products/142-neodymium-prices (Vr) of the Cu roll are 5 m/s, 15m/s, 25m/s and 35m/s, ribbons have been fabricated. XRD study on no-contact surface of CeCo5.4 ribbons shows that: The existence of the (111) strong peaks in 5m/s ribbons indicates that the crystal grains near no-contact surface have strong axis orientation, most crystal grains’(111) plane parallel to the surface
　　of the ribbons, that is, [111] axis perpendicular to the surface of the ribbons, with the C-axis distributed in the [111] axis angle of about 50o of a cone. The (111) peaks of 15m/s, 25m/s and 35m/s ribbons gradually weakened, the (110) and (200) peaks gradually increased, thus, most C-axis changed to parallel to the surface of the ribbons.Magnetic properties of CeCo5.4 ribbons were tested along the ribbon length, ribbon width and perpendicular to the ribbon plane by Vibrating Sample Magnetometer (VSM), ribbon length direction is always easy magnetization direction. Thinking over the test results of XRD, we can figure out that C-axis should prefer to arrange along the ribbon length direction. For the ribbons spun at Vr=5m/s, the difficult magnetization direction is along ribbon width, and for those spun at Vr=15m/s, 25m/s and 35m/s the difficult magnetization direction perpendicular to the ribbon plane, consistent with the crystallographic texture evident in the XRD pattern’s comparison. Using magnetic moments in three directions and Vr curve to describe the changing trends of magnetic anisotropy as Vr change, we can find out that magnetic anisotropy weakens as Vr increases.Large numbers of angle stripes were observed by scanning electron microscopy (SEM) in the sections of ribbons, which exist in most ribbons. Ares contain stripes shrink as Vr increase, and magnetic anisotropy weaken, so we can relate the stripes with magnetic anisotropy. In addition, scanning electron micrographs for the non-contact surfaces of ribbons show that grain size decrease as Vr increase. On the other hand, coercivity increase as grain size decrease, therefore, it is an effective way to increase coercivity by decreasing grain size.2. melt-spun CeCo5 and CeCo4.6ribbonsAlthough orientated textures exist in melt-spun CeCo5.4 ribbons, the coercivities are too low to satisfy the practical requirements. For the reason that the magnetic anisotropy field of Rare Earth - Transition alloy increases as the rare-earth content increases, we fabricated melt-spun CeCo5 and CeCo4.6 ribbons as well. Besides crystal axis orientation and magnetic anisotropy we find out that, with Ce content increase, the magnetic anisotropy of ribbons spun at low Vr enhanced, and the trend of isotropy with Vr increased enhenced. The coercivities increased as well.II. Structure and magnetic properties of CeCo4.5Cu0.9 ternary alloy ribbons For sintered CeCo5 permanent magnet, precipitation hardening effect could be caused by dropping
　　Cu element, which will improve coercivity. Thus, CeCo4.5Cu0.9 ribbons were fabricated. XRD and VSM test showed that for the ribbons spun at Vr=5m/s and 15m/s strong rystal-axis orientation existed; for the ribbons spun at Vr=25m/s and 35m/s tended to isotropic. Precipitation hardening effect performed good in the ribbons spun at 5m/s for coercivity improved notablely, and hardly performed in the ribbons spun at 25m/s and 35m/s for most Cu solute in Ce(Co,Cu)5, which reduce the anisotropy field and decrease the coercivity.Heat treatments were prepared to further enhance the coercivity. Large numbers of Cu separated out after 15min 400℃anneal, which was test by SEM and EDX. At the same time, hysteresis loop appeared serious Fengyao phenomenon. We conjecture that 400℃anneal process led to Ce (Co, Cu) 5→Ce2 (Co, Cu)17 + Ce5 (Co, Cu)19 + Cu decomposition reaction, the emergence of low coercivity 2:17 phase caused Fengyao phenomenon. After 15min 500℃anneal, less Cu seperated out and Fengyao phenomenon gradually disappeared. Anneal promoted the formation of CeCu5, precipitation-hardening effect caused further improvement of coercivity.III. http://www.999magnet.com/products/142-neodymium-prices Structure and magnetic properties of CeCo4Fe0.5Cu0.9 quaternary alloy ribbonsDropping Cu element can increase the coercivity but decrease the magnetic moment. Therefore, Fe element was dropped to increase magnetic moment without decrease coercivity. Crystal axis orientation existed in CeCo4Cu0.9Fe0.5 ribbons, (111) strong peaks existed in the ribbons spun at low Vr, and crystal-axis orientation existed. Ribbons spun at high Vr trended to isotropy. Dropping Fe element increased magnetic moment and decrease coercivity slightly. Structure and magnetic properties of CeCo4Cu0.9Fe0.5 ribbons could also be imporved by heat treatment. Excellent magnetic properties have been obtained by 500℃anneal for 15 min. On the one hand, coercivity improved significantly, especially for the ribbons spun at Vr=5m/s, the coercivity has reached 4200 Oe, which is far more than CeCo5.4 ribbons’300 Oe. On the other hand, magnetic moment decreased slightly. Furthermore, the coercivity decreased notablely and magnetic moment increased after 600℃anneal for 15 min.

Research and Design on PMSM AC Servo Control System

　　Research and Design on PMSM AC Servo Control System
　　Servo System is a sort of advanced control systems, whose output can respond the external input rapidly and accurately.Due to the great development of the microprocessor technique, modern power electronic technique, control technique and the manufacture technics for the permanent magnet material of motors.higher control performance of Cast Alnico Magnet servo products with lower cost is being a subject of great interest worldwide. Digital controlled AC servo systems, based on Permanent Magnet Synchronous Motors (PMSM) as power converters with advanced control strategies, implemented in Digital Signal Processor (DSP), will be a trend.In this thesis, a set of practical PMSM speed-adjustment system based on DSP controller is developed, especially for the inverter’s, The improved SVPWM pattern was realized in order to decrease the motors torque ripple and http://www.chinamagnets.biz/Alnico/Cast-Alnico-Magnet.php enhance the system’s high speed and accuracy. basing on which a relevant method of control strategy is also advanced. analyzing the principle in detail, a software system for putting the method in practice is further developed.At last, the designed controller is simulated under MATLAB/SIMULINK, and the results are gived.

水下航行器推进用永磁电机工作状态热分析

　　水下航行器推进用永磁电机工作状态热分析
　　The advantage of permanent magnet motor is simple structure, mini volume and higher efficiency, so it is used as a propel motor in electric under-water vehicle. In this paper, a study on steady temperature field of a DC permanent magnet motor used in under-water vehicle is presented, and, the effect of the motor efficiency caused by the increase of rubber magnetic sheet temperature is analyzed.First, the heat resource and the limit of the increase of temperature are presented based on normal theory of motor’s temperature increase. Then, the boundary condition of motor’s heat transfer is analyzed, on the theory about heat transfer. And, the motor’s temperature field is calculated by a finite element software, ANSYS, the temperature of motor’s parts is confirmed. In the last place, the decrease of motor’s efficiency is ascertained, and the author brings some advice. http://www.chinamagnets.biz/rubber/rubber-magnetic-sheet.php All of this presents a theory foundation on motor design and improve.In addition, based on the finite element analyze of motor composed nearly by fifty parts, a method of finite element analyze in multi-part system is founded, which indicates the function of finite element technology in the study on field.