Research on the DSP Based Servo System for the Permanent Magnet Synchronous Motor

　　Research on the DSP Based Servo System for the Permanent Magnet Synchronous Motor
　　Servo System is a sort of advanced control systems,whose output can respond the external input rapidly and accurately.Servo systems are ever-increasingly utiized in many fields,including industrial controllers,household appliances and Aeronautics and Astronautics. Modern industrial manufacturing requires more excellent performance of servo equipments, therefore,it is quite important to study and develop AC servo system with high performance and high reliability.In the field of servo,In the structure characteristic and operation,the permanent magnet synchronous motor is more outstanding performance and broader scope than other types of traditional servo motor. http://www.999magnet.com/products/112-neodymium-standard-state   Permanent Magnet Synchronous Motot(PMSM) is applied more and more in AC servo system.Digital controlled AC servo systems will be the trend,which uses Permanent Magnet Synchronous Motors(PMSM) as power units and high quality control strategy,based on DSP.Based on the research of operation theory of the PMSM,the details of the field-orientation vector control theory are presented in this paper,the i_d=0 scheme and the Space Vector Pulse Width Modulation(SVPWM) method is chosen.The digital signal processor(DSP) TMS320LF2407 made by TI Company is adopted as core of the control system in this paper.A full-digital PMSM servo system is developed based on DSP.The design and debugging of all of the control system circuits and periphery assistant circuits is also explained,including the power driving circuit,the power supply circuit and the sensor circuit etc.The software,programmed by Assembly program under the CCStudio2.2 Integrated Development Environment(IDE) provided by TI Company,Complete the main program modules and subroutine module design,Realizing the current A/D sampling, Switching model,speed PI adjuster,etc.Two close loop vector control with feedback of position,speed and current are realized.The flow charts of main program and Each subroutine module are given in the paper.The experimental results show that the servo control system designed in this thesis has the response speed,small over-correction,speed,torque,wide range of speed etc,has good dynamic and static characteristic and high precision,so it achieves the expectative effect basically.Prove the feasibility of the design of the system. 更多还原

Study on Nonlinear Control Strategy for the Permanent Magnet Synchronous Motor

　　Study on Nonlinear Control Strategy for the Permanent Magnet Synchronous Motor
　　Permanent Magnet Synchronous Motors(PMSM) have been widely used in industrial and agricultural production and the field of Aeronautics and Astronautics for their advantages, such as compactness,high efficiency,reliability and adaptability to the environment.Along with the continuous development of these areas,the speed control system for PMSM urgently needs to have http://www.999magnet.com/products/142-neodymium-price better precision,wider speed-regulating range and faster response.Based on the overview of PMSM speed control system development,this thesis firstly presents the process of building the mathematic model for an Interior Permanent Magnet Synchronous Motors (IPMSM),and then we mainly develop a few nonlinear control algorithms of PMSM for the speed regulation and tracking based on this model.PMSM is a highly nonlinear and coupling,structure varying,and multivariable object. Firstly,the mathematical model of PMSM is built under the d-q coordinates.After analysis of vector control strategies,we chose i_d=0 control strategy to decouple the system.For the highly nonlinear characteristics of PMSM,backstepping control method is adopted.This method has fewer design parameters and can be easily realized,furthermore the design rule of backstepping makes global asymptotical stabilization with Lyapunov function.Taking into account the variability of the parameters in PMSM,adaptive parameter estimation method is introduced into the backstepping control under Lyapunov stability.With the promotion of applications and different requirements in different areas,the speed is asked to be changed over time.This thesis designs a new backstepping controller to make the speed control system effectively and closely track the varying speed.Because the presence of speed sensor is undesirable for cost,maintenance and reliability reasons,a kind of sensorless backstepping control based on a speed estimator is designed in this thesis.All the above controllers are proved to be effective by the theory and simulation.The thesis is summarized at the end and some conclusions and future works are pointed out. 更多还原

Intelligent Variable-Structure Position Control of Permanent Magnet Linear Synchronous Motor

　　Intelligent Variable-Structure Position Control of Permanent Magnet Linear Synchronous Motor
　　Compared with conventional rotary motor and scroll lever, a linear motor servo system has removed the bad effects which are caused by mechanical gearings. But it adds the difficulties in the aspect of electrical control. We should stand in a higher level and take deeper http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php consideration about some disturbs or some uncertain factors in situation of higher precision and tinier process. Otherwise, zero mechanical gearing makes nonsense.Above all, this thesis introduces the basic principle and related control strategy of linear motor. The permanent magnet linear synchronous motor smathematics model based on space vector transform laws is established. After deducing the dq model and thrust equations, the control method and principle of PMLSM field oriented control are obtained.Focused on the limitations of traditional PID strategy, a variable-structure controller, using a recurrent fuzzy neural network (RFNN) to control the mover position of PMLSM servo drive is developed. To further improve the rate of convergence of the estimation, a variable structure controller using an RFNN is investigated, in which the RFNN is utilised to estimate the real time uncertainties. With external disturbances, position error and speed perturbation are apparently reduced, and the system is robust to external disturbances. The proposed algorithm and its stability are analyzed in details. The simulation based on MATLAB/Simulink is concluded. The system prototype based on dual DSPs and dual windings are developed. The experimental and some possible improved methods are also discussed. 更多还原

Sensorless Control of Surface Permanent Magnet Synchronous Motor at Low Speed

　　Sensorless Control of Surface Permanent Magnet Synchronous Motor at Low Speed
　　Permanent magnet synchronous motors (PMSM) are widely used in servo control fields. The traditional servo system needs high precision position and velocity sensors. However, these position sensors or rotational transducers not only increase complexity and cost, but also impair reliability of the system. With this background, the research on sensorless control has become an attractive prospect. At present, there have been numerous achievements on sensorless operation, http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php but most of the techniques only rely on machine fundamental equations which limit the operation at zero and low speeds of the machine and are sensitive to machine parameters. Therefore, this thesis focuses on the sensorless control at low speeds.In this thesis, the work concentrates on the study of surface permanent magnet synchronous motor (SPMSM) drive system without mechanical sensors. Firstly, mathematical model of SPMSM is set up based on motor electromagnetism. The principle of i_d = 0 control method is analyzed systematically based on vector control technique of PMSM. Vector control system is set up. Space vector PWM technology (SVPWM) is introduced.Based on the saliency tracking idea, the fluctuating high frequency voltage signal injection method is discussed. For the nonsalient magnetic structure of SPMSM, principle of developing saliency is introduced.
　　The basic principle of rotor position self-sensing using fluctuating high frequency signal injection method are presented and the simulation model for sensorless vector control systems of a permanent magnet synchronous motor was established and analyzed. Simulation results indicate that the salient pole tracking system that using fluctuating high frequency voltage signal injection method has more advantages, which has simple structure, good static and dynamic performances and easy realization. This method can effectively detect rotor’s position and velocity at low speeds .The sensorless vector control system has good static and dynamic performances, and is insensitivity to motor parameter variation. At last, the hardware and software were designed for the sensorless vector control systems of PMSM. Elementary experimentation was studied. DSP was used to confirm the accuracy of high frequency voltage signal method. 更多还原

permanent magnet actuator,intrinsic

关键词:low voltage control,permanent magnet actuator,intrinsic

safety,vacuum contactor
摘要:This paper reports a new application of permanent magnet

actuator for vacuum contactors.A novel permanent magnet(PM)

actuator to drive a vacuum contactor Neodymium Magnets with intrinsically safe and

low supply voltage is proposed.PM is mounted on the static iron

of the contactor to enhance its holding force and

reliability.While only one coil is used to break the vacuum

contactor,two series coils http://www.999magnet.com/products/110-sintered-neodymium-magnets are deployed to yield a high

magnetomotive force to realize the making operation.The

electrical circuit equation,mechanical equation and magnetic

field are all coupled in the simulation.A prototype is

manufactured and tested to validate and showcase the performance

of the contactor which is equipped with the proposed PM actuator.

magnetic field properties

作者:孙献静;邓昌东;康文;
关键词:CSNS, RCS, transient electromagnetic simulation, thermal

analysis
单位:Institute of High Energy Physics,Chinese Academy of

Sciences;
摘要:Due to the large eddy currents at the ends of the quadrupole

magnets for CSNS/RCS, the magnetic field magnetic materials properties and the heat

generation are of great concern. In this paper, we take transient

electromagnetic simulation and make use of the eddy current loss

from the transient electromagnetic http://www.999magnet.com results to perform thermal

analysis. Through analysis of the simulated results, the magnetic

field dynamic properties of these magnets and a temperature rise

are achieved. Finally, the accuracy of the thermal analysis is

confirmed by a test of the prototype quadrupole magnet of the

RCS.

phosphating;ultrasonic

关键词:sintered NdFeB magnet;phosphating;ultrasonic

wave;corrosion resistance
摘要:The corrosion behavior of a NdFeB magnet obtained at room

temperature,with and without ultrasonic were investigated.The

corrosion resistance was investigated by neodymium standard state corrosion immersion

tests in 3 wt%neutral NaCl solutions,potentiodynamic polarization

tests and electrochemical impedance spectroscopy(EIS).The

morphology of the conversion coatings on NdFeB surface were

analyzed by scanning electron http://www.999magnet.com/products/112-neodymium-standard-state microscopy(SEM).And the forming

mechanism of coatings was studied by potential-time curves.The

tests of corrosion resistances show that the combination of

phosphating treatment with ultrasonic will further improve the

corrosion resistance of the NdFeB.The SEM also confirms that

phosphating coating under ultrasonic is more homogeneous and

compact.

Chemistry, Peking University

作者:顾菡珍,吴念祖,叶于浦
关键词:切吸:4375,北京大学:3789,新金属材料:3777,翻台:3299,钢铁研究

:2975,万宁:2803,化学系:2785,剑兰:2783,角门:2573,百万:1580
单位:Department of Chemistry, Ball Neodymium Magnets
http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php Peking University





,Department

of Chemistry, Peking University





,Department of Chemistry,

Peking University
摘要:<正> In the preceding article, the approach was made mainly

to the effect of various factors on the magnetic performance in

the preparation of SmCo_5 by the Reduction-Diffusion Process.

Some of the samples were produced using water pulvermation and

solid phase sintering, which gave rather satisfactory results. In

order to make this technology applicable to production on a

larger scale it is

Engieering, Academia Sinica,

作者:韩朔,张超骥,旷远达,冯之鑫,罗昆崙,宋守森,黄惠志,高志远,李克文

,陈月莲
单位:Institute of Electrical Engieering, Block neodymium magnet
http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php Academia Sinica,

Beijing





,Institute of Electrical Engieering, Academia

Sinica, Beijing





,Institute of Electrical Engieering,

Academia Sinica, Beijing





,Institute of Electrical

Engieering, Academia Sinica, Beijing





,Institute of

Electrical Engieering, Academia Sinica, Beijing





,Institute

of Electrical Engieering, Academia Sinica, Beijing





,

Institute of Electrical Engieering, Academia Sinica, Beijing







,Institute of Electrical Engieering, Academia Sinica, Beijing







,Institute of Electrical Engieering, Academia Sinica, Beijing







,Institute of Electrical Engieering, Academia Sinica, Beijing
摘要:<正> Superconducting dipole and quadrapole magnets with high

field homogeneity and high gradient are required in high energy

physics experiments.There are two types of dipole magnet, one has

iron shield and the other has not. The latter is dangerous

Free piston (FP), Linear alternator (LA),

关键词:Free piston (FP), Linear alternator (LA), Internal combustion engine (ICE), Finite element method (FEM)
摘要:We proposed the flat-type permanent magnetic materials
http://www.999magnet.com magnet linear alternator (LA) for free piston linear alternators (FPLAs) instead of the tubular one. Using the finite element method (FEM), we compare these two kinds of LAs. The FEM result shows that the flat-type permanent magnet LA has higher efficiency and larger output specific power than the tubular one, therefore more suitable for FPLAs, and that the alternator design can be optimized with respect to the permanent magnet length as well as the air gap.

Jointly supported by the National Natural Scien

摘要:<正>Jointly supported by the National Natural Science Foundation of China,Ministry of Science and Technology and Chinese Academy of Sciences,Ma Xucun's group in CAS Institute of Physics Neodymium Magnets
http://www.999magnet.com/products/110-sintered-neodymium-magnets and Condensed Matter Physics National Lab,in cooperation with Xue Qikun's research team in the Department of Physics of Tsinghua University,studied the super exchange mechanism in cobalt phthalocyanine(CoPc)thin films


关键词:sintered NdFeB permanent magnet; Ni-P/TiO2 composite film; sodium chloride solution; corrosion resistance
摘要:The Ni-P/TiO2 composite film on sintered NdFeB permanent magnet was investigated by X-ray diffraction (XRD),environmental scanning electron microscopy (ESEM),and energy dispersive X-ray spectrometer (EDX). The corrosion resistance of Ni-P/TiO2 film coated on NdFeB magnet,in 0.5 mol/L NaCl solution,was studied by potentiodynamic polarization,salt spray test and electrochemical impedance spectroscopy (EIS) techniques. The self-corrosion current density (icorr) and the polarization resistance (Rp) of Ni-P/TiO2 film are 0.22 μA/cm2 (about 14% of that of Ni-P coating),and 120 kΩ·cm2 (about 2 times of that of Ni-P coating),respectively. The anti-salt spray time of Ni-P/TiO2 film is about 2.5 times of that of the Ni-P coating. The results indicate that Ni-P/TiO2 film has a better corrosion resistance than Ni-P coating,and the composite film increases the corrosion resistance of NdFeB magnet markedly.

Elevator door system, Tubular permanent magnet linear

关键词:Elevator door system, Tubular permanent magnet linear synchronous motor (TPMLSM), Finite element analysis(FEA)
摘要:A novel elevator door driven by tubular permanent magnet linear synchronous motor (TPMLSM) is presented. This TPMLSM neodymium price
http://www.999magnet.com/products/142-neodymium-price applies axial magnet array topology of the secondary rod, air-cored armature windings and slotless structure of the forcer to improve the stability of the thrust. The influence of two major dimensions, the pitch and radius of the permanent magnet (PM), on magnetic field was studied and the best values were given by the finite element analysis (FEA). The magnetic field, back EMF and thrust of the motor were analyzed and the PM size was optimized to reduce the harmonic components of the magnetic field and improve the performance of the motor. Predicted results are validated by the experiment. It is shown that the performance of the motor and the novel elevator door system is satisfying.

Permanent Magnet Synchronous Motor

关键词:Permanent Magnet Synchronous Motor, Passive system, State observer
摘要:Passive system theory was applied to propose a new passive control method with nonlinear observer of the Permanent Magnet Synchronous Motor chaotic system. Through constructing a Lyapunov function, neodymium price
http://www.999magnet.com/products/142-neodymium-price the subsystem of the Permanent Magnet Synchronous Motor chaotic system could be proved to be globally stable at the equilibrium point. Then a controller with smooth state feedback is designed so that the Permanent Magnet Synchronous Motor chaotic system can be equivalent to a passive system. To get the state variables of the controller, the nonlinear observer is also studied. It is found that the outputs of the nonlinear observer can approximate the state variables of the Permanent Magnet Synchronous Motor chaotic system if the system’s nonlinear function is a globally Lipschitz function. Simulation results showed that the equivalent passive system of Permanent Magnet Synchronous Motor chaotic system could be globally asymptotically stabilized by smooth state feedback in the observed parameter convergence condition area.

permanent magnet

关键词:rare earths; permanent magnet; settling; separation
摘要:Mechanism and characteristics of magnetic particle′s solid-liquid separation in rare earth magnetic Neodymium Magnets
http://www.999magnet.com/products/110-sintered-neodymium-magnets field were studied. Magnetic force resulted from magnet is a function of magnet′s magnetization M and particle′s position x. It weakens significantly with increase of spatial distance x. Two groups of comparative experiments were carried out. It was found out that presence of Nd-Fe-B magnet gives much shorter free settling and pressing time in gravitational separation and shorter pressing time in centrifugal separation. Expressions for effective acting distance of permanent magnetic field in gravitational settling and centrifugal settling were summarized based on the analysis and experiments.

NdFeB magnets; alloying; coercivity

作者:宋晓平,杨森,王献辉,孙占波,孙军
关键词:rare earths; NdFeB magnets; alloying; coercivity
摘要:Alloying elements Cu and Ti were added to the intergranular regions of sintered NdFeB magnets and their effects magnetic materials
http://www.999magnet.com on microstructure and magnetic properties were investigated. The results show that small amounts of Cu/Ti additives can enhance the coercivity greatly and have little effect on the remanence of the magnets, while Ti content is less than 1  2%. The improvement of the coercivity can be attributed to the segregation of Cu and Ti on the surface of main phase, which inhibits the growth of main phase grains during sintering. At the same time, segregation of Cu and Ti can also prevent the magnetic coupling of Nd  2Fe    14  B grains to a certain degree and impede effectively the propagation of reversed domain walls through the magnetic phase grains. As the Ti content increased above 1  2% a strip  like Ti  rich phase appears in the intergranular region, resulting in the dramatic reduction of the remanence of Nd  Fe  B magnets. Compared with the single alloying method, the combined alloying of intergranular regions is more efficient to modify the properties of NdFeB magnets.

Particle size, Particle

关键词:Rare earths, NdFeB neodymium standard state
http://www.999magnet.com/products/112-neodymium-standard-state powder, Particle size, Particle









distribution, Magnetic properties
摘要:ＰｏｌｙｍｅｒｂｏｎｄｅｄＮｄＦｅＢｐｅｒｍａｎｅｎｔｍａｇｎｅｔ，ｆｉｒｓｔｌｙａｐｐｅａｒｅｄｉｎ１９８０ｓ，ｉｓａｎｅｗｔｙｐｅｏｆｐｅｒｍａｎｅｎｔｍａｇｎｅｔｉｃｃｏｍｐｏｓｉｔｅ，ｗｈｉｃｈｃｏｎｓｉｓｔｓｏｆＮｄＦｅＢｐｅｒｍａｎｅ...


作者:刘湘涟,何建平,董清飞,周寿增
关键词:rare earths; NdFeB-type magnet; sintering; grain growth kinetics
摘要:The Nd  2Fe    14  B grain growth kinetics in sintered NdFeB magnets with nominal compositions of   Nd    30+x  Dy    1.5  Fe    67.08-x  Al    0.4  B    1.02     (%, x=0, 3) was studied. The grain size parameters were determined by means of the linear intercept method on SEM secondary electron images. It is observed that the grain growth process is more sensitive to sintering temperature than to sintering time although the grain size rises with both sintering temperature and time. It is also found that magnets prepared from the pre-alloy powder with a higher oxygen content exhibit a lower grain growth rate and magnets made from the pre-alloy powder with a broader particle size distribution demonstrate a higher grain growth rate. It is believed that the presence of appropriate amounts of Nd oxides effectively impedes the grain growth process and a larger difference in sizes between pre-alloy powder particles significantly accelerates the grain growth process. On the basis of experimental results, the grain growth exponent and the corresponding activation energy were obtained. A possible grain growth mechanism in NdFeB magnets during sintering was briefly discussed.

microstructure; magnetic force microscope

作者:吕友胜;陈翌庆;苏勇;成问好;熊永飞;依晓飞;周庆涛;
关键词:NdFeB; microstructure; magnetic force microscope; domain structure; rare earths
单位:School of Materials Science magnetic materials
http://www.999magnet.com and Engineering  Hefei University of Technology,School of Materials Science and Engineering Hefei University of Technology,School of Materials Science and Engineering Hefei University of Technology,Earth Wind Advance Magnetic Material Co. Ltd.,Earth Wind Advance Magnetic Material Co. Ltd.,Earth Wind Advance Magnetic Material Co. Ltd.,School of Materials Science and Engineering Hefei University of Technology,,Hefei 230009 China,Hefei 230009 China,Hefei 230009 China,Lujiang,Anhui,China,Lujiang,Anhui,China,Lujiang,Anhui,China,Hefei 230009 China
摘要:A new alloy of Nd33.5Dy0.99Febal.Al0.52Cu0.1B1.15 (%, mass fraction) was fabricated by powder metallurgy. The effects of Dy, Al and Cu additions on the microstructure and magnetic properties of sintered NdFeB magnet were investigated. The additions of Dy, Al and Cu are effective to refine grains and improve coercivity. Moreover, suitable amounts of Dy, Al and Cu lead to a demagnetization curve with good rectangularity. It is found that the sintered NdFeB magnet has relatively high magnetic performance of Br=12.17 kGs, jHc=13.52 kOe and (BH)max=34.71 MGOe. The sintered NdFeB sample was examined by magnetic force microscope which revealed the domain structures at the surface. It is revealed that the mean Nd2Fe14B grain size is significantly larger than the average scale of the magnetic contrast. An explanation about this is that most Nd2Fe14B grains in sintered NdFeB alloy are dominated with the multidomain structures when the magnet is in thermally demagnetization state.

sintered NdFeB permanent magnet

作者:于升学;陈玲;
关键词:sintered NdFeB permanent magnet; Zn-Cr coating; magnet property; anticorrosion property; rare earths
单位:Department of Applied Chemistry  Yanshan University Qinhuangdao 066004 China,Department of Applied Chemistry Yanshan University Qinhuangdao 066004 China,
摘要:Zn-Cr coating was prepared Neodymium Magnets
http://www.999magnet.com/products/110-sintered-neodymium-magnets on the surface of sintered NdFeB permanent magnet samples and preparation parameters were established. The anticorrosive property of Zn-Cr coating on NdFeB was studied by whole-immersion test in NaCl solution and compared with that of zinc plating and nickel plating on NdFeB. Open-circuit potential and self-corrosion current of NdFeB samples with and without Zn-Cr coating were measured. The micro-morphology and composition of Zn-Cr coating were analyzed through SEM, XPS, EDS and XRD. The effect of Zn-Cr coating on magnetic property of NdFeB magnet was also investigated. It is exposed that Zn-Cr coating is anodic type coating for NdFeB magnet, and provided substrate electrochemical protection, barrier protection and passivation protection. The anticorrosion property of NdFeB magnet is obviously enhanced by Zn-Cr coating while the magnet property of NdFeB magnet changed little.

nanocomposite magnets; melt spinning

作者:王伟,倪建森,徐晖,周邦新,李强,王占勇
关键词:nanocomposite magnets; melt spinning; exchange coupling; rare earths
单位:Institute of Materials, neodymium prices
http://www.999magnet.com/products/142-neodymium-prices Research Center of Nano-Science and Nano-Technology, Shanghai University, Shanghai 200072, China








,Institute of Materials, Research Center of Nano-Science and Nano-Technology, Shanghai University, Shanghai 200072, China








,Institute of Materials, Research Center of Nano-Science and Nano-Technology, Shanghai University, Shanghai 200072, China








,Institute of Materials, Research Center of Nano-Science and Nano-Technology, Shanghai University, Shanghai 200072, China








,Institute of Materials, Research Center of Nano-Science and Nano-Technology, Shanghai University, Shanghai 200072, China








,Institute of Materials, Research Center of Nano-Science and Nano-Technology, Shanghai University, Shanghai 200072, China
摘要:Nd_(11)Fe_(71)Co_8V_(1.5)Cr_1B_(7.5) magnet was prepared by melt-spinning and subsequently annealed. The effects of the wheel speed on the magnetic properties and microstructure were studied. The results reveal that fine nanocomposite microstructure consisting of Nd_2Fe_(14)B and α-Fe phases can be developed at an optimum wheel speed of about 21 m·s~(-1). After optimal annealing (640 ℃×4 min), magnetic properties of B_r=0.64 T, (()_jH_c)=903.5 kA·m~(-1) and (BH)_(max)=71 (kJ·m~(-3)) were obtained for the bonded magnets. The addition of Cr element significantly reduces grain size, increasing the intrinsic coercivity and maximum magnetic energy product.

Calibration,Commissioning

关键词:Booster,Magnet,Calibration,Commissioning
摘要:The Shanghai Synchrotron Radiation Facility (SSRF) is a low

emittance third-generation synchrotron radiation light source

under commissioning. The excitation Neodymium Magnets curve calibration for the

booster magnets is important to provide the magnet current

configurations as reference. Calibration studies give the

polynomial coefficients of each type of magnets and provide the

magnet current configurations under different beam energies as

beam is ramped at speed of 2 Hz. http://www.999magnet.com/products/110-sintered-neodymium-magnets The applications of calibration

in booster commissioning which show the accuracy of the magnetic

excitation curve calibration are also discussed.

rare earth permanent magnets

者:彭龙;杨青慧;张怀武;徐光亮;张明;王敬东;
关键词:rare earth permanent magnets; SmCo alloys; coercivity;

temperature coefficient
单位:State Key Laboratory of Electronic Thin Films and Integrated

Devices  University of Electronic Science and Technology of

China,State Key Laboratory of neodymium prices Electronic Thin Films and

Integrated Devices University of Electronic Science and

Technology of China,State Key Laboratory of Electronic Thin Films

and Integrated Devices University of Electronic Science and

Technology of China,Shcool of Materials Science and Engineering

Southwest University of Science and Technology,Southwest

Institute of Applied Magnetics,Southwest Institute of Applied

Magnetics,,Chengdu 610054,China,Chengdu 610054,China,Chengdu

610054,China,Mianyang 621010 China,Mianyang 621000 China,Mianyang

621000 China
摘要:Sintered Sm(CobalFexCu0.1Zr0.03)7.5 (x=0.09-0.21) permanent

magnets with higher Fe content were found to have higher

remanence Br and maximum energy http://www.999magnet.com/products/142-neodymium-prices product (BH)max at room

temperature. Br and (BH)max reached maximum of 0.96 T and 176.7

kJ/m3, respectively at room temperature when the Fe content x

reached 0.21. However, the intrinsic coercivity Hci at room

temperature increased gradually when the Fe content x increased

from 0.09 to 0.15, but when x further increased to 0.21, Hci

decreased. Hci attained its peak value of 2276.6 kA/m with Fe

content x=0.15 at room temperature. For magnets with x=0.15, Br,

(BH)max and Hci reached 0.67 T, 81.2 kJ/m3 and 509.4 kA/m at 500

°C, respectively, showing good high temperature stability, which

could be used in high temperature applications.

NdFeB magnets; intergranular addition; magnetic

作者:莫文剑;张澜庭;刘琼珍;单爱党;吴建生;Komuro Matahiro;沈丽萍;
关键词:NdFeB magnets; intergranular addition; magnetic

properties; corrosion resistance; microstructure; rare earths
单位:School of Materials Science and Engineering  Shanghai Jiao

Tong University,School of Materials Science and Engineering

Shanghai Jiao Tong University,School Block neodymium magnet of Materials Science and

Engineering Shanghai Jiao Tong University,School of Materials

Science and Engineering Shanghai Jiao Tong University,School of

Materials Science and Engineering Shanghai Jiao Tong

University,Advanced Research Laboratory Hitachi Ltd. Hitachi-shi

Ibaraki-ken 319-1292 Japan,http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php Hitachi (China) Research & Development

Corporation Shanghai Branch,,Shanghai 200240 China,Shanghai

200240 China,Shanghai 200240 China,Shanghai 200240 China,Shanghai

200240 China,Shanghai 200020 China
摘要:Microstructure and corrosion resistance of sintered

Nd15Dy1.2Fe77Al0.8B6 and Nd22Fe71B7 magnets modified by

intergranular addi- tion of MgO and ZnO were investigated. Both

the remanence and sintering density of the magnets increased

slightly with intergranular addi- tions of MgO and ZnO. There was

a remarkable increase in coercivity of Nd22Fe71B7 after addition.

Besides, the effects on magnetic proper- ties and an improved

corrosion resistance were observed. Compared with the native

magnets without addition, corrosion potential of the magnets with

MgO and ZnO additives was more positive and the current density

in the anodic branch of the polarization curve was reduced.

Corrosion resistance resulting from autoclave testing (2×105 Pa

of steam pressure, 120 °C) showed that the corrosion rate of

NdFeB magnets reduced with the increase of additive amount.

Microstructure observation revealed that MgO and ZnO additives

were incorporated into the intergranular phases in the magnets.

With the introduction of MgO and ZnO, more intergranular phase

with high oxygen content was formed while keeping the volume

fraction of all the intergranular phases almost unchanged, which

may contribute to improved corrosion resistance. Furthermore,

addition of MgO and ZnO refined the grain size of Nd22Fe71B7.

strip casting technique; rare earth permanent magnet

作者:韩卫平;郭炳麟;喻晓军;祝景汉;程星华;
关键词:strip casting technique; rare earth permanent magnet

material; rare earth hydrogen storage alloy; columnar crystal
单位:Functional Material Division Advanced Technology & Materials

Co.,Ltd,Functional Material Division,Ball Neodymium Magnets Advanced Technology &

Materials Co.,Ltd,Functional Material Division,Advanced

Technology & Materials Co.,Ltd,Functional Material

Division,Advanced Technology & Materials Co.,Ltd,Functional

Material Division,Advanced Technology & Materials

Co.,Ltd,,Beijing 100081 China,Beijing 100081 China,Beijing 100081

China,Beijing 100081 China,Beijing 100081 China
摘要:The SC technique is now being applied widely in material

preparation, especially in rare earth functional materials in

virtue of its advanced process and high performance product. The

applications of SC technique in rare earth permanent magnet

alloys and hydrogen storage alloys http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php were analyzed integrative, on

the basis of summary of SC technique development in this paper.

The paper mainly includes development history of SC technology,

effect of SC technology on alloy microstructure, application of

SC technology in RE storage hydrogen alloy and sintered Nd-Fe-B

alloy, development of SC equipment and SC product industry. At

the same time, the paper points out the existing problem of SC

products.

nanocomposite; temperature coefficient; magnetic

作者:张士岩;徐晖;谭晓华;倪建森;董远达;
关键词:nanocomposite; temperature coefficient; magnetic

properties; Zr addition
单位:Institute of Material Science  Shanghai University,Institute

of Material Science Shanghai University,Institute of Material

Science Shanghai University,Institute of Neodymium Magnets Material Science

Shanghai University,Institute of Material Science Shanghai

University,,Shanghai 200072,China,Shanghai 200072,China,Shanghai

200072,China,Shanghai 200072,China,Shanghai 200072,China
摘要:The influence of Zr addition on magnetic properties and

temperature coefficient for nanocomposite Nd10Fe78.5-xCo5ZrxB6.5

(x=0～4) bonded magnets was investigated. It was found that the

room-temperature magnetic properties were remarkably improved

with Zr addition due to the grain refinement and increasing

volume fraction of the hard magnetic phase. The optimal magnetic

properties of Jr=0.689 T, iHc=769.4 kA·m-1 and (BH)max=84 kJ·m

-3 were obtained for 2.5% Zr http://www.999magnet.com/products/110-sintered-neodymium-magnets addition. The temperature

coefficient of remanence (α) increases slightly and the

temperature coefficient of coercivity (β) decreases obviously

with increasing Zr content for nanocomposite Nd10Fe78.5-

xCo5ZrxB6.5 (x=0～4) bonded magnets.

Application of Neural Networks PID Algorithm in Rotation and Location Control for the Crucible

Application of Neural Networks PID Algorithm in Rotation and Location Control for the Crucible

 A new method of controlling the rotation and location of the single crystal furnace crucible is present in the dissertation, which bases on the technology of single crystal silicon growth, and designs the hardware circuit according and program to the require. It respectively controls the rotation and location of the single crystal furnace by a piece of single-chip micyoco 80C196KC. The drive motor of the single crystal furnace crucible is the permanent magnetism direct-current servo motor, and the drive neodymium standard state of the motor adopts MOSFET which is as the master element in the control. There are many merits of the permanent magnet direct-current servo motor, such as the volume is small, the weight is light, the output power is big, the efficacy is high, the structure is simple, the initiating performance is good, operation is smooth, and it can control the speed in the extensive range. In the growth of the single crystal silicon, it adopts the signal of diameter and weight that are detected by the sensors of diameter and weight as the controlling data of diameter. The way can improve the accuracy of the diameter.Because the controlling object has the characters of nonlinearity, time-varying, time delay, the general PID controller is difficult to come to the exact controlling. It adopts the calculation of PWM space ratio by the combination of ANN and traditional PID algorithm, and then adjusting the output of the PWM of the single-chip computer, to realize the adjustment http://www.999magnet.com/products/112-neodymium-standard-state of armature voltage of the motor, and to control the rotation and location of the single crystal furnace crucible. The system can ensure the stability and robustness in the process of the crystal growth, and make the error of the diameter much smaller than the present standard +/-1 mm, it also can improve the quality of the crystal growth and the rate of finished products. 更多还原

无刷直流鱼雷推进电机控制器设计

无刷直流鱼雷推进电机控制器设计

 The thesis discusses the state-of-the-art of BLDCM and the pending further study of the main issue. The thesis discusses the key-technology about a control system project which applied to a large power capacity rare earth permanent magnet brushless DC motor (BLDCM), neodymium prices

http://www.999magnet.com/products/142-neodymium-prices designs the hardware and software of the BLDCM control system.The thesis analyzes the causes of the torque ripple BLDCM and the commutation current. Building the BLDCM model under the conditions of the magnetic circuit which is not saturated, eddy current and hysteresis loss which is not consider, the three-phase windings of the brushless DC motor which is completely symmetrical. Compare with the torque in non-commutation interval, analyzing the torque formula in different current slopes. Derivation different torque ripple in different current slopes. Combining the formula was derived and references, then bringing up the method which is based on the hysteresis current law to restrain torque ripple. Next, the method of regulating the speed of BLDCM is studied detailedly. On the basis of fuzzy control, Fuzzy controller regulate the speed with hysteresis current regulator bicyclic current regulation governing system PID controller and with the use of speed adjustment current hysteresis current regulator with the adjustment bicyclic systems in MATLAB simulation speed, proved its superiority in less torque ripple and less speed change; On the basis of the above, TMS320LF2407A control subsystem based on the complete hardware design: The clock module, memory modules, etc. According to the hardware design, the main program flow, speed adjustment, the current regulation, and commutation logic are completely designed by DSP. 更多还原

Study on Back-EMF Method and Starting Technique of BLDCM

Study on Back-EMF Method and Starting Technique of BLDCM

 Brushless DC motor(BLDCM) is a kind of electromechanical integration machinery, and it has been rapidly developing in recent years with the help of the Neodymium Magnets

http://www.999magnet.com/products/110-sintered-neodymium-magnets development of power electronic technique and the appearance of new type of permanent magnet material. With it’s widely used in many fields, sensorless control especially back-EMF method is more useful than sensor control in many applications.In this paper the common methods of sensorless control of BLDCM are introduced, and the principle of back-EMF method is illustrated in detail. The control system adopts high capability chip dsPIC30f2010. In this paper every circuit is introduced, the AD sampling circuit and hardware filter are carefully introduced. Based on the hard circuit the design of software is explained.The back-EMF amplitude is direct ratio with the speed of motor, so we can not get the position of rotor when the motor is still. Because of this we have to use special starting method. After discuss "three-step" starting procedure which is locating, accelerating and switching, we discuss a new starting method which is locating, switching. We clearly explain this method and the conditions whether this method can be used. The test proved that this method is resultful. We discuss the effect to the phase which turned off when use different PWM modulating way. We design software filters to induce the disturb and the impulse cased by the diode.The results of the experiment show that this system , which is made on the base of the theory above, can control the sensorless BLDC motor to complete the exact commutation. The system presents good static and dynamic performance. 更多还原

Studies on Transdermal Delivery System of Electret Meloxicam Patch

　　Studies on Transdermal Delivery System of Electret Meloxicam Patch
　　Transdermal drug delivery system (TTDS) is a new formulation which treats or prevents diseases by the skin administration. TTDS can maintain drug blood level, avoid hepatic first-pass elimination, decrease side effects, and extend drug effective time, facilitate and enhance long-term treatment of patients with compliance. However, there are only limited number of chemicals, which have low molecular weight (<500), low melting point (<200℃), low-dose (≤20mg·d-1) and high lipophilicity (log P = 1～3), are neodymium standard state suitable for TDDS due to the barrier function of the outmost layer of the skin.Meloxicam is a small molecule and lipophilic drug with the molecular weight of 351.41 and LogP=1.01. Its daily dose is less than 10mg and melting point, determined in our experiment, is 247.1℃.As a whole, meloxicam is suitable for TDDS.However, it is difficult for some drug to achieve therapeutic effect because of physiological barrier function of the stratum corneum. Therefore, it is of much importance to overcome barrier effect of skin and to promote penetration amount of drugs within a certain period of time.Some strategies, consisting of chemical and physical enhancers, have been investigated and developed in order to overcome the barrier properties of the skin and thus enhance drug transdermal absorption.
　　Penetration enhancers, such as Azone, ethyl oleate, menthol, propylene glycol, dimethyl sulfoxidend are commonly used. On the other hand, iontophoresis is an enhancement technique that improves transdermal drug transport through the application of a low-level electric current.Eelectret is the electrostatic equivalent of a permanent magnet and can generate internal and external electric fields. Our previous studies indicated that electret can improve the circulation of blood, enhance the wound healing, regulate the cell growth and apoptosis, modify the electret state of skin, and enhance the transdermal drug delivery.The primary aim of this paper was to characterize enhancing effect of electret on the maloxicam transdermal absorption through rat skin as compared with chemical enhancers, to understand in detail the magnetic materials possible mechanisms by which electret enhances molecular transport across the skin, to investigate the possible synergic effect of the application of chemical enhancers and electret, to prepare a meloxicam electret patch formulation and to study its pharmacodynamics for inflammation and pain.
　　The solubilities of meloxicam in octanol or phosphrte buffer solution (PBS) with different pH were determined by UV method and the partition coefficient was calculated accordingly. The results showed that (1) The octanol-water partition coefficient of meloxicam logP was 0.97 which is similar to the reported value. (2) The solubility of meloxicam increased with the increasing of pH of the buffer solution. The in vitro permeation study indicated that (1) 1%, 3% and 5% azones show a 1.18, 1.33, 1.26 times increase of the cumulated permeation amount of meloxiam in 10h as compared with that of in control group(p<0.05).The enhancing effect was ranged in following order: 3% azone >5% azone >1% azone; (2) Most of the chemical enhancers used in this study were shown to have enhancing effects except for 20% propylene glycol. Among them, 10% ethyl oleate was proved to be the most effective one, showing a 1.86 times increase of the cumulated permeation amount of meloxiam in 10h as compared with that of in control group(p<0.05); (3) Negative electret was more effective than the chemical enhancers used in this study in meloxicam trasdermal delivery, showing a 2.16 times increase of the cumulated permeation amount of meloxiam in 10h as compared with that of in control group(p<0.05); (4) Electret can improve the enhacing effect of chemical enhancers in this study. The cumulated permeation amount of meloxicam for chemical enhancer with electret patchs in 10h were 1.14 to 2.89 times that of the meloxicam patchs with chemical enhancers only(p<0.05); (5) The cumulated permeation amounts of meloxicam for 10% ethyl oleate with negative electret patch was the largest in all of the patchs, showing a 4.53 times increase as compard with that of in control group ( p<0.01). In order to explain and explore the electret enhancing mechanism, electron microscopy specimen was used to observe the rat skin’s ultrastructural change and confocal laser scanning microscopy (CLSM) was used to study the mechanisms of drug skin permeation enhancement after the rats skin was treated with electret for 2h. The studies revealed that the enhancing effect of electret on meloxicam transdermal delivery was not only through changing the structure of the stratum corneum cells to achieve, but also to a large extent through broadening the hair follicle to obtain.Based on the above findings, we prepared meloxicam patch combining 10% ethyl oleate with negative electret. The effects of the plasticizer and drug content on adhension of the patches were observed. The study showed that the more the content of plasticizer, the stronger the tack of the patch was, but the waker the cohesion of the patch was. The effect of meloxicam was opposite to plasticizer.
　　Optimal formulation was achieved by orthogonal experiment on considering the factors of cohesion of the patch and cumulated released amount of meloxicam from the patch. The methodology for determination the quality of electret meloxicam patch was studied. The results showed that electret meloxicam patch was of uniform thickness, moderate adhension. The releasing rate, stability, toxicity and irritability studies indicated that electret meloxicam patch was a safe, nontocix and non irritant formulation.In addition, the mice retortion pain models induced by acetic acid and mice auriculate tumefaction models caused by xylene were established in the paper. The results showed that the inhibitory ratio of retortion of mice induced by acetic acid in electret meloxicam patch was 63.30% (p<0.01), which was higher than that in meloxicam patch (55.85%) and oral meloxicam suspension (54.25%). the inhibitory ratio of auriculate tumefaction of mice caused by xylene in electret meloxicam patch was 34.20% (p<0.05), which was also higher than that in meloxicam patch (22.14%) and oral meloxicam suspension (24.60% ).In this paper, the electret meloxicam patch combined both the physical and chemical enhacing methods. Electret demonstrated its unique effect as a new, non-toxic, safe physical method in this Neodymium Magnets paper. The studies proved that electret could be used as excellent enhancer in transdermal permeation of meloxicam. Meanwhile, electret meloxicam patch was a kind of multiple effective anti-inflammatory analgesic patch, which integrated chemical and physical treatment into a one. It took advantage of the pharmacological effects of meloxicam and characteristics of electret which can adjust skin in biological electret state and weakened pain caused by injure and improved the effect of the analgesic drug.

直线式自发电技术探索研究

　　直线式自发电技术探索研究
　　With the development of intelligent and smart munitions, the demand of anti-highoverloading, transient high power, ten-year’s storage or longer and miniaturization poweron munitions is extremely urgent. The physics power not only has nondestructive testingand reusable characters but also has advantage in long storage and using of high and lowtemperature. And because of the use of the high quality permanent magnetic materials,more neodymium standard state and more military experts in the world pay attention to the micro physics power onmunitions.This article discusses how to transform high overload line inertial force to theelectricity generation driving force in artillery launch process. First the article makes thebasic theory of magnetic circuit about straight line electric power facility, in thisfoundation establishes magnetic circuit computation matfiematical model, makes theequivalent magnetic circuit graph, and also infers magnetic circuit equation about how tosolve straight line electric power facility, then makes the use of ’matlab’ solving air gapmagnetic flux and electromotive force, thus realizes the ’circuit ’simulation about thestraight line electric power facility. Second, magnetic materials the article makes the use of maturecomputation magnetic field software ’ANSYS’ to the thorough research, considers manykinds of factors which affect the magnetic field, obtains mass data and curves. And makesthe comparison of magnetic circuit computed results, fits various parameters how toinfluent the electromotive force, after optimization obtains the referenced parameters.

Simulation and Study on Power Train of ZH Micro-Hybrid Electric Vehicle

　　Simulation and Study on Power Train of ZH Micro-Hybrid Electric Vehicle
　　Hybrid Electric Vehicle (HEV) is the vehicle that is powered by internal combustion engine (ICE) and motor together. It makes full use of the two power sources and can optimally match their power, So that it can enlarge the efficiency of the overall system. At present HEV has been researched hotly inland and oversea. With deep research of 863 Electric Vehicle huge projects, HEV will be next vehicle. Now some automotive works have been released their sample of HEV inland. For example, the First Automotive Work group has been released their HEV of middle bus and Hongqi HEV; and Dongfeng group has been released HEV of middle bus and Dongfeng HEV; and Qirui has been neodymium prices released its BSG and ISG and so on.This paper is research on the power system of Zhonghua mild HEV that based on“Research on technology keys about Zhonghua HEV”(2005AA501770)of“863 Electric Vehicle huge project”. To achieve aim of the mild HEV, firstly researching on theory about reducing fuel and choosing parts of the power system, secondly compiling control strategy and applying ADVISOR simulation soft, finally simulating and analysis on power system.Firstly this paper researched advantage of 42 voltage vehicle electrical source system, and analyzed energy distribution of the conventional vehicle. Through analyzing the micro HEV、the mild HEV and the full HEV, a 42 voltage power system of the mild HEV that based on ISG(integrated starter/generator).
　　The power system is composed: engine is mature gasoline 4G63; motor is permanent magnet direct current brushless motor that starter coil and assistant coil are different; battery is mature http://www.999magnet.com/products/142-neodymium-prices lead-acid battery; gearbox is five speeds. Secondly through researching on theory about reducing fuel and configuration foundation, this paper designed the mild HEV control　 strategy suiting to this power system, and designed hardware and software of this control system. Basing on standard and protocol of CAN(controller area network) bus, designing the protocol、hardware and software correction to CAN.Finally under the environment of MATLAB/Simulink, regarding ADVISOR as the simulation platform, the 42 voltage power system’s simulation models are constructed based on modification of“Insight”simulation modules of ADVISOR. Including control strategy module engine open-closed module motor controller module and battery module. According to test data and result of every parts of the power system, then the dynamic performance and fuel economy on the ECE-EUCD, UDDS and Japan 10-15 driving cycle are simulated by ADVISOR soft. Compared with the conventional vehicle of similar dynamic performance, the fuel economy and dynamic of the mild HEV are greatly improved.Conclusion: The whole design, modeling and simulation have reached the anticipated design object.

Magnetic Compression Ostomy as New Cystostomy Technique in the Rat: Magnacystostomy

　　Magnetic Compression Ostomy as New Cystostomy Technique in the Rat: Magnacystostomy
　　Ibrahim Uygun , Mehmet Hanifi Okur , Hasan Cimen , Aysenur Keles , Ozben Yalcin , Hayrettin Ozturk , Selcuk Otcu
　　Department of Pediatric Surgery and Pediatric Urology , Medical Faculty of Dicle University , Diyarbakir , Turkey , Department of Pathology , Medical Faculty of Dicle University , Diyarbakir , Neodymium Magnets
http://www.999magnet.com/products/110-sintered-neodymium-magnets Turkey , Department of Pathology , Hospital of Children , Diyarbakir , Turkey , Department of Pediatric Surgery and Pediatric Urology , Medical Faculty of Abant Izzet Baysal University , Bolu , Turkey
　　Objective To report the first creation of magnetic compression cystostomy (magnacystostomy) using an easy and simple new technique in rats. Magnetic compression anastomoses (magnamosis) have been previously described for gastrointestinal, biliary, urinary, and vascular anastomoses. Methods Female rats were randomized into 2 groups (n = 10 each): a magnetic cystostomy group and a formal surgical cystostomy group as the control group. In the magnetic cystostomy group, a very small cylindrical magn ...et was inserted into the bladder. The external magnetic ball was placed subcutaneously into the suprapubic region, and the 2 magnets were coupled together strongly. On postoperative day 20 in the magnetic cystostomy group and day 10 in the surgical cystostomy group, the rats were killed, and the cystostomies were evaluated macroscopically, histopathologically, and by mechanical burst testing. Results In the surgical cystostomy group, 3 rats died. In the remaining rats, no evidence of complications was observed. However, mild adhesion in 1 rat in the magnetic cystostomy group and moderate adhesions in all the rats in the surgical cystostomy group were observed. No significant difference was found in burst pressure between the 2 groups (mean 162 mm Hg in the magnetic cystostomy group [n = 6] and 185 mm Hg in the surgical cystostomy [n = 5] group). However, the procedure time between the magnetic cystostomy group (7.70 ± 1.64 minutes) and surgical cystostomy group (18.50 ± 2.01 minutes) was significantly different ( P < .001). Conclusion Magnacystostomy is easy and safe in the rat model and could be useful for some suprapubic cystostomy procedures in humans.

Study and Design of Brushless DC Motor Control System Based on DSP

　　Study and Design of Brushless DC Motor Control System Based on DSP
　　With the development of high permanent magnetic material, modern power electronic technology, computer control technology , furthermore, the emergence of MCU and high performance DSP specially Cast Alnico Magnet used to control motors, it becomes possible in recent years to make a typical model of brushless DC motor and to be widely used. Thus, brushless DC motor is a new device involving in many subjects. It has advantages of high speed, high efficiency, high dynamic response, high temperature bearing capacity and reliability. It also behaves a long life and low noise characteristics. There are extensive applications at many realms, such http://www.chinamagnets.biz/Alnico/Cast-Alnico-Magnet.php as computer system, electrical home appliances, Industry, traffic and the medical equipment and so on. The research of brushless DC motor is an important topic now in China,.DSP is developing in the foundation of variable theories and arithmetic,

Study on Digital Magnetic Measurement Method and System Based on Electromagnetic Induction

　　Study on Digital Magnetic Measurement Method and System Based on Electromagnetic Induction
　　During the past 30 years, the magnetic technology which is represented by the electromagnetic actuator, the permanent magnet technology and their applications has been developed greatly. The magnetic technology has many applications. In this case, the magnetic measurement technology has also been advanced and becomes the research hotspots in the related field. In our country, the traditional analog measuring devices are not satisfied. Therefore, it is urgent to develop a digital magnetic measuring system which can satisfy the need of the industry and scientific research.Based on the Faraday’s neodymium prices law of electromagnetic induction, the thesis presents a digital magnetic measuring system with human operation interface whose core is the MSP430F149 single chip, and studies the theories and technology referring to the sensor and inspecting, the data treatment and the results output in the system. Then series of measuring experiments are carried out with the system, and the results indicate that this magnetic measuring system can meet the prospective requirements.Firstly, the paper reviewed the development and research status quo of the magnetic measurement technology in and out of the country, and pointed out that the magnetic application and magnetic measurement technology’s mutual promotion accelerated the appearance of some new ways and technology in related field and deepened the magnetic measurement theory http://www.999magnet.com/products/142-neodymium-prices and technology.
　　The research focus on the digital minitype magnetic measurement device and the 3D digital middletype one are the research hot issues. Then, the related theory and technique of magnetic measurement based on electromagnetic induction are presented. The referring magnetic laws, the digital techniques and the measurement methods for absolute time-changing field, the position-changing field and the time-position-changing field are all included in this chapter. Besides, measuring different system’s magnetic field, the coil sensors with various shapes and the data treatment method are studied. In the following chapter, the paper has discussed the problems of magnetic measurement using Helmholtz coils, setting up the Helmholtz coils model, analyzing the magnetic field with finite element

Research on the Control System of Double-Side Linear Electrical Oil Pumping Unit

　　Research on the Control System of Double-Side Linear Electrical Oil Pumping Unit
　　The energy transformation and delivery of traditional beam pumping unit power equipment are so complex that the efficiency and reliability of beam pumping unit are poor. Linear electrical pumping unit is a revolution of the energy transformation and delivery mode, can improve the efficiency of pumping unit, can realizes the smooth pumping parameters and the suspension center movement variation with pumping situation, and gives a good foundation for intelligent pumping unit. The linear electrical pumping unit is a revolution of pumping unit structure. The driver and control system in Neodymium Magnets the paper is an important part of the special linear electrical pumping unit, which is the first the double sides permanent magnetic brushless DC linear motor applied in the pumping unit.First, with the information of the oil pumping equipment in nation and abroad, the pretend of the oil pumping equipment is proposed, which indicates that it is good choice to apply the linear motor in the oil pumping, because the characteristic of linear motor is suit for the oil pumping.Then the working process of the linear electrical pumping unit is introduced. Three phase double-side linear brushless motor is chosen for the great force characteristic, high efficiency, simple structure and control characteristic.The drive and control system is the main body of the paper.Hardware of the drive and control system is based on TMS320LF2407A with powerful functions, transforms the power energy into PWM to drive and control the motor and realize the protective function by protective circuit. Software of the http://www.999magnet.com/products/110-sintered-neodymium-magnets drive and control system realizes the current and speed closed-loop control, which contain PI adjuster.
　　The control system could realize the step stroke variation and commutation by switch signal and corresponding software. Otherwise, we have got the way to realize smooth stroke variation based on the phase change signal count.Speed detection is one of the key technologies of speed control, but the traditional Hall position sensor’s way applied in the first experiment has poor precision at low speed, then we propose a novel speed detection way, which changes the traditional speed detection mode, gets the speed by induced electromotive force produce by a coil moving with the mover. The novel way could improve the

Wind Force Solar and Gas Supplementary Heating System Design and Simulation

　　Wind Force Solar and Gas Supplementary Heating System Design and Simulation
　　Today energy sources dried up and environmental pollution is more and more serious, the people are long for that renewable energy sources take the place of rule energy resources, the pollution environment conventional energy source. It is indicated that the solar energy and wind force can be richest renewable energy in the research and the practice, they distribute widely, may regenerate, does not pollute the environment, are the neodymium prices internationally recognized ideal substitution energy sources.This paper is take the renewable energy comprehensive utilization as the guiding ideology, can has the good complementarity according to the solar energy in the resources condition and the technical application characteristic, carries on the integrated system design and the simulation.In the paper through to the wind force and solar hybrid heating system and originally heating system cost accounting comparison, has confirmed the wind force and solar hybrid heating system energy conservation feasibility, and according to the heating system structure, has determined the system principle of work, the movement way and the function; Has designed a set in this foundation take the AT89S53 monolithic http://www.999magnet.com/products/142-neodymium-prices integrated circuit as the control core, by the sensor, changes delivering, the signal recuperates the intelligence control system which, component and so on monolithic integrated circuit, functional element, monitor and keyboard is composed, and to the control system in each module function, the principle of work has made the detailed narration; Also elaborated the wind energy basic theory, established the wind speed, has straight driven the type permanent magnetism synchronous generator the mathematical model.Finally, utilizing Matlab7.1/Simulink5.0 simulation software, the wind force generation system each constituent simulation model is established, and the simulation model has been carried on. It is known through the simulation graphs the simulation model established is correct.

Research on Power Control Technology for Stand-alone Small Wind Power Generation Systems

　　Research on Power Control Technology for Stand-alone Small Wind Power Generation Systems
　　For stand-alone small wind power generation systems, the Maximum Power Point Tracking (MPPT) control is an important method of improving power conversion efficiency, and the reasonable management and control of battery is an important means of prolonging their life. A power control strategy, which combines MPPT control and charging and discharging control of batteries with load tracking control, is given to make the small wind power generation systems to operate in both optimal and reliable conditions in this Cast Alnico Magnet thesis. Firstly, the background of research work is introduced, and the domestic and oversea development of wind power is summarized. The configuration of small wind power generation systems with simple structure, which consists of wind turbine, PMSG, diode rectifying bridge, Buck converter, batteries, and controller, is put forward to realize the power control strategy.
　　Based on the analysis of work principle of the system, the mathematic model of components and simulation model of entire system are established, and the relationship between output power of turbine and duty of Buck converter is calculated and drawn.Secondly, after analyzing several MPPT methods such as the small sine perturbation, optimum torque curve and perturbation observation, a variable step perturbation MPPT method is http://www.chinamagnets.biz/Alnico/Cast-Alnico-Magnet.php given, and the charging and discharging control of batteries is discussed. Based on analyzing the relationship between output power of turbine, and load power and batteries state, a power control strategy which integrates variable step perturbation MPPT, charging and discharging control of batteries and load tracking control is given for the small wind power generation systems. The simulation results show that, compared with the fixed step size MPPT, the variable step perturbation MPPT achieves better performance in precision and rapidity for the small wind power generation systems.Finally, the structure and parameters of main circuit for power control is designed in detail, and the inductor and Buck converter are made and tested in lab. The experimental results prove that the main circuit is feasible and correct.

ICP-MS测定镝铁合金中杂质元素的分析方法研究

　　ICP-MS测定镝铁合金中杂质元素的分析方法研究
　　Dysprosium-iron alloy is an important additive of Nd-Fe-B permanent magnetic alloy. Dysprosium-iron alloy is requested to be more and more pure in order to meet the demand of final products. There are limited reports on analytical method of Dysprosium-iron alloy except Arc Atomic Emission Spectrometry and ICP-AES which possess such disadvantages as low sensitivity of partial elements , short of prime standard, labor intensity and rubber magnetic sheet limited application range. Methods have been proposed for the determination of impurities in dysprosium-iron alloy by ICP-MS in this paper. The methods, which are simple and rapid with accurate results, can highly meet the requirements of product inspection. In addition, economic and social benefits can also be achieved.The method has been developed for determination of rare earth impurities in dysprosium -iron alloy by ICP-MS, and the operation condition of the instrument was optimized and the correction equation was established.
　　The reliable quantitation limit are 0.2μg/g for La, Ce, Eu, Er, Tm, Yb, Y; and 0.4μg/g for Pr, Nd, Sm, Gd, Tb, Ho, Lu. The recovery of standard addition is 93-102%, RSD is less than 5%.The accuracy of the results obtained is confirmed by the determination of elements after standard addition procedure. The method is accurate, rapid and applicable to routine analysis.The method has been developed for determination of nonrare earth impurities (A1, Mg , Ni, Mn, Cr, Cu, Pb, Co, Zn, As, Cd, V) in dysprosium-iron alloy by ICP-MS. The limits of determination are all less than 1μg/g, The recovery of standard addition is 95---109%,RSD is less than 10%.The method has been developed for determination of refractory mental impurities (Ta, Nb, Zr, Hf, W, Ti, Mo) by ICP-MS after the complexation of hydrofluoric acid. The interference http://www.chinamagnets.biz/rubber/rubber-magnetic-sheet.php of salts deposition and dysprosium fluoride and the function of internal standard method have been investigated. The limits is less than 0.5μg/g. The recovery of standard addition is 93～105%.RSD is less than 10%.The influencing factors on uncertainty of measurement result for tungsten in dysprosium-iron alloy are studied by ICP-MS. The components of uncertainty of measurement result are analyzed and calculated. The expanded uncertainty of measurement result for tungsten is 12.28μtg/g when mass fraction of tungsten in the dysprosium-iron alloy is 97.5μg/g.The interference of dysprosium-iron alloy has been studied .The mass and non-mass spectra interferences of dysprosium-iron alloy have been discussed. The reasons why interferences occur as well as the removal methods have been presented.

Research on AC Servo Control Computation Simulation and Experiment Platform Build

　　Research on AC Servo Control Computation Simulation and Experiment Platform Build
　　With the demand of high-powered AC servo product increasing, the AC servo system based on SCM (single-chip microcontroller) is more and more widely used. For digitized AC servo system, it needs software to support it’s closed-loop control. Its control quality is decided by the program of control computation directly. So the program should be tested strictly and time after time when developing it. For the test is long, unefficient and costly with hardware, it’s adverse for the AC servo product to compete Neodymium Magnets
http://www.999magnet.com/products/110-sintered-neodymium-magnets in the intense market.The present paper’s goal is to put forward a new way to test the program by means of multi-cyclical closed-loop control computation simulation. For this paper, it’s an exploration for the improvement of the program test. In this paper, a new idea of the program test is put forward. Its concrete method is: Firstly, precondition the program code. Secondly, collect information which will be put use to simulate. Lastly, make use of the information collected to simulate to compute, and associate with the controlled object’s program module to carry out the multi-cyclical closed-loop simulation. This method‘s realization will make the time and cost of A.C. servo system’s development reduce greatly, so it will make sense for the research and http://www.999magnet.com/products/110-sintered-neodymium-magnets the practical application. In this paper, the AC servo system for experiment is based on SCM UPD70F3184, V850 series which produced by NEC. This equipment will be used to validate the new way of program test. Not only, this system provides the experiment platform for the method of simulating to confirmed, but it makes author to strengthen to understand the AC servo system. The research and summary for AC servo system will laid the rationale for the simulation of control computation.Based on above work, an emulator used to carry out the multi-circle closed–loop simulation for the control computation program., and the AC servo system is put use to confirm its feasibility.

基于Rogowski线圈12KV电流传感器研制

　　基于Rogowski线圈12KV电流传感器研制
　　Current transformers are important component for current measurement and relaying protection in power system. With the development of power system, on one hand, the capacity of the power system is increasing very rapidly and the system current becomes larger and larger. On the other hand, with the optimization of the administration and allocation of the power energy, the traditional CT can’t meet the demand. Our company’new product(VSM) is very urgent to develop a new type of CT to meet such requirement.neodymium prices
http://www.999magnet.com/products/142-neodymium-prices According to the actuality of the present research on CT, this paper introduces the measurement principle of Rogowski coil and analyzes the factor that influence the precision of measurement, we bring forward a new design scheme based on the Rogowski coil. In this design, the protection in short circuit failure and the measurement in normal condition are both fulfilled. It can also communicate with the computer through the communicating interface, sending the parameter of the system current and accepting the instruction.In order http://www.999magnet.com/products/142-neodymium-prices to validate the rationality of study, the rogowski coil was designed and manufactured. The controller based on STC89C51, including the hardware and the software, are designed according to the measurement and control demand of system. The CT worked well through the experimental test. According to the causation of the error, the adjustment part is adopted in the design. For instance, the screen cover for rogowski coil are designed. In the processing of signal, the adjustment part is adopted. In the programming of software we put forward the methods to solve these problems. This can make the system more secure and reliable.Based on the research in theory, the prototype of rogowski coil CT was manufactured and tested, the practicability was validated.

Research of Fuzzy Self-tuning 2DOF-PID Controller for PMSM

　　PMSM的模糊自调整二自由度控制器的研究
　　Research of Fuzzy Self-tuning 2DOF-PID Controller for PMSM
　　The PMSM servo-system is widely applied to high performace driven field,such as flexible manufacture,CNC machinary tools,elevator adjust-speed etc. the PMSM has many individual features because of its structure and operation. A this paper the mathematical model and controller of PMSM are studied.The traditional PID control is abroad used to magnetic materials
http://www.999magnet.com  the motion control field for its simple mechanism and its flexible structure.But between the system tracking and the anti-disturbance performance,it can not find the better balance, an its parameters adjustment depend on the accurate model of the controlled process: the more clear machanism analysis of the controlled process is recognized, the more accurate mathematical model is developed, the more appropriate parameters are tuned, and the better control results are reached.However, the PMSM variables have been strongly coupled,at this time the system is non-linear, time varying process, it is difficult to describe the system with mathematical model. For these features of PMSM, in this thesis, the two-degree-of-freedom(2-DOF)PID control is introduced, one of the intelligent control-Fuzzy technique is added. Several control schemes are introduced and presented as follows:(1) To improve the traditional PID control which can not keep the system tracking and the anti-disturbance performance in good condition simultaneously, the necessity to use the new type of 2-DOF PID control in drive systems is illustrated. furthermore, the advanced-two-degree-of-freedom PID and the super-two-degree-of-freedom PID are provided. The simulation results demonstrate that these two methods solved the mentioned problem of the conventional PID control.(2) Integrate the Super-two-degree-of-freedom PID control with fuzzy techniques, a self-tuning PID controller bassed on fuzzy inference is designed. On-line automatically tuned parameters are realized at different states. Many simulation experiments have done are proven the controller can overcome model mismatch, and it is strongly adaptability and robustness.

Study of Ring Linear Motor Direct Drive Control System Used in Roller Coaster

　　Study of Ring Linear Motor Direct Drive Control System Used in Roller Coaster
　　With the improvement of living standards, the quality of recreational demands higher .The roller coaster is the recreational facilities that are necessary for large playground. Traditional roller coaster wide area, the high cost of the launch is not controllable. In order to pursue the roller coaster the efficiency and the strong irritating quality, the people continuously are seeking a better structure and the launch technology. This article proposed one kind of new structure and the launch Neodymium Magnets http://www.999magnet.com/products/110-sintered-neodymium-magnets  technology ring-like roller coaster permanent magnetism brushless the direct current straight line motor-driven the ring-like roller coaster. The article mainly study the roller coaster launch technology and the ring-like straight line brushless the direct current machine the design and the control technology.The principal elements are as follows :The article first consulted and summarized the straight line electrical machinery characteristic as well as function in the transportation application, obtained that the brushless direct current straight line electrical machinery is suit to actuate the roller coaster theconclusion.In explaining ring linear brushless DC motor based on the basic structure and principles. Ring design based on ring linear brushless DC motor driven roller coaster of the structure and section power supply.In explaining the basic http://www.999magnet.com/products/110-sintered-neodymium-magnets principles of infinite element method based on using ANSYSsoftware to ring DC linear motors modeling, analysis of the magnetic field distribution and thrust. Followed by the establishment of a ring linear brushless DC motor linear mathematical model.PID algorithm is the most widely used and most mature industries algorithm. In the PID operation, the output has the possibility to surpass thescope, moreover differentiator to deviation sudden change is very sensitive, and easy to create the control performance the instability, this article uses the advanced version PID algorithm - to meet limit weaken the integration and differential equation.The control system of the roller coaster with DSPTM320LF2407, introduces double closed-loop (velocity loop and current loop) control, the speed control circuit design, the current detection circuit, the motor electrical power supply circuit. and has compiled complete software, then unified the hardware to carry on the debugging, initially has realized the electrical machinery change phase operation and the electrical machinery subsection control strategy.

回旋速调管中的电子枪的设计

　　回旋速调管中的电子枪的设计
　　Gyro-devices are important sources for millimeter wave and sub-millimeter withthe characteristics of high peak power, high average power, high efficiency andsuitability bandwidth and so on. Especially gyrotron has the superiorities high peakpower and high average power with other apparatus. So gyrotron is vastly applied inmany areas, such as power source of millimeter wave high capability radar, millimeterwave weapons system, millimeter wave communication plasma heating, electroncountermeasure. Especially in later thirty years, gyrotron has been played much respectin magnetic materials America, Russia, England, France, Japan, German and so on. Interiorly, the UESTCHigh Power Microwave Laboratory has studied gyrotron since the late 1970s. At2001, our group leaded has successfully developed the first Ka band third harmonicgyrotron with permanent magnetic field system in the world and reach advanced levelinternationally. Gyrotron electron gun provides the helical ring beam,
　　The beamcharacteristics affect interaction output power and efficiency directly. Combinging withthe prospect of our laboratory, design the small-orbit electron gun and the large-orbitelectron gun, Especially stress the design and study of the large-orbit electron gun.The main works of the dissertation are listed as following:First, know the theoretical basis and software use of EGUN, MAGIC. Representthe theory and calculation method of electron optics.Second, represent the http://www.999magnet.com operation principle of the gyrotron electron gun and makethe detailed analyse. Represent the initial design method and optimization means.Third, modulate the small-orbit electron gun and obtain a series of significativeinclusions. Study shows finishing initial design of gun we can optimize the beamperformance by adjusting magnetic field distribution, gun geometry, cathode magneticfield, magnetic field compression ratio, anode voltage and so on.Fourth, set up the model of the large-orbit electron gun, and make theoreticalanalysis and design of the large-orbit electron gun. Due to applying large-orbit electrongun, the velocity spread is lower because of smaller influence of space charge compared with small-orbit electron gun. In the interaction region this beam is easy to startoscillation and reject mode competition effectively.

Study of Motion Controller Based on TMS320F2812

　　Study of Motion Controller Based on TMS320F2812
　　In the latest years, with the appearance of some control methods such as vector control and direct torque control, the dynamic and static performance of motion control system have got great improvements. Because complicated real-time computing is needed for those new control theories including fuzzy control, neural networks control, sliding mode variable structure control, adaptive control and expert control, the microprocessor with higher performance is necessary for the system realization. TMS320F2812 is the most advanced DSP chip applying to motion control which is recently produced by TI. TMS320F2812 is compatible with the F24x/240 series DSP chips. In Neodymium Magnets addition, the computing speed is more quickly, the memory capacity of data and program is bigger, the integration degree is higher and the A/D transition is more accurate and rapid.The system characteristic of vector control and direct torque control is analyzed, and the dynamic and static performance is researched in this paper. Then the AC stepping drive theory is deeply analyzed and studied on these bases. The AC stepping drive is a new research branch which is formed with the development of motion control. It is a new-type mode of drive which is powered by static frequency converter under the control of microprocessor to make the stator magnetic motive force motion discretely and then the http://www.999magnet.com/products/110-sintered-neodymium-magnets position and speed output is got from the axis of motor. The AC stepping drive control combine different modes of drives such as position control, speed control, servo control and etc. so that the AC stepping drive control system with high performance is realized.
　　A new-type motion control system is researched and designed in the paper. The controller applies TMS320F2812 which is a powerful 32-bit fixed point DSP chip as its control core, and can apply AC stepping control theory. First introduces the hardware design and construction of the system. Then illuminates the software realization of the step-motion control, C language is used for designing the software. Experimental results are presented, and it is confirmed that the new control system based on TMS320F2812 is able to achieve complex arithmetic, has nice control performance.

A Design of Test and Analysis System of Servo Control

　　A Design of Test and Analysis System of Servo Control
　　This thesis introduced the design on a servo control system performance analysis and on-line system model identification. With the fast development of modern science, motion control, especially, the high speed high precision servo control is widely used in many fields of high technology. In order to improve the performance of servo control system, it is necessary to acquire the accurate system model and analyze system’s performance. Generally, the analysis of magnetic materials on-line system with the load is harder than off-line. But on-line analysis is helpful for application to set up proper parameter.First, the model of typical speed servo system is set up. The time and frequency domain index of servo control system and their influence on system testing is analyzed, and a method of frequency analysis-Fourier Transform and it’s fast arithmetic-FFT are introduced. Then the theory of correlative identification and how to use it in identifying the pulse response of servo control system is introduced. Finally, a hardware platform is established for data sampling and processing. Based on Ti’s CCS as development environment, C language is used to code the main program. In software the whole test system is http://www.999magnet.com separated into three parts, which are the time and frequency domain analysis of servo control system, the harmonic analysis of line voltage and the identification of pulse response of servo control system.In experiment, a high speed and high precision servo control system formed by Huazhong numeric control company’s motor driver HSV-16D-050 and Wuhan Dengqi company’s permanent magnet motor GK-7080-6AC61-FE is chosen as test object. The experiment results show that this test system can perform the desired analysis and test function.