PMSM Control System Based on Digital Signal Processor

Transcription

1 9 JOURNAL OF NETWORKS, VOL. 8, NO., ARIL MSM Control System Base on Digital Signal rocessor Zhu Jun, Li Wankui, Han Lili Henan olytechnic University, College of Electrical Engineering an Automation, Henan Jiaozuo, China Abstract For the high power ensity of MSM, esigne the corresponing rive controller to improve the servo efficiency of MSM servo system. Accoring to the theory of math moel of MSM uner the q coorinate system, applie i = vector control metho as a MSM control strategy, establishe MSM controller moel base on vector control. Taking DS TMSF8 as controller core, built a powerriven circuit, control circuit an the main etection protection circuit. The algorithm of control program was complete on the harware platform to present its software processes. The simulation results show that: the control system response is fast, can track the given spee an position quickly an accurately. The spee fluctuation, overshoot an steay state error are very small. The esigne controller is reasonable, which has better ynamic an static characteristics, an be benefit to improve the efficiency of MSM servo system. Inex Terms MSM, Overall Control system, DS, Controller I. INTRODUCTION With the rapi evelopment of permanent magnet materials, power electronics an control theory, base on vector control of MSM its excellent control performance, high power ensity an high efficiency, more an more use in a variety of highperformance servo systems an other fiels of inustrial prouction []. In recent years, the evelopment of various control metho [] an vector control theory an methos become mature graually, the progress of integrate circuits an computer technology, the MSM vector control system has been a great evelopment. The vector control of MSM base on the mathematical moel in the q coorinate system, through conversion of vector moel; realize that it has completely ecouple control of stator current. It has like a DC motor control performance, an thus more wiely applie [5]. This paper introuces the mathematical moel of MSM in the q coorinate system, moeling an analysis of MSM vector control strategies base on the i =, for DS TMSF8 as controller core, built a powerriven circuit, control circuit, feeback circuit an the main auxiliary circuit. The algorithm of control program was complete base the harware platform, an presente its software processes. Constitute a highperformance MSM vector control system, an through experimental results emonstrate the superiority of the system. II.SYSTEM MODEL A.The Mathematical Moel of the MSM By the assumption of the esire motor, can be euce from the mathematical moel of MSM in q coorinate system []: Stator flux equation: ψ = Li ψ f () ψ q= Li q q () In the formula, i, i q is the qaxis stator current; ψ, ψ q is the qaxis stator flux; L, L q is the q axis stator inuctance; ψ f is the magnetic potential generate by the permanent magnets on the rotor. Stator voltage equation: ψ u = R i ω ψ () s r q t ψ q u = R i ω ψ () q s q r t In the formula, u, uq is the qaxis stator voltage; ω r is the rotor angular velocity; R s is the stator resistance. Electromagnetic torque equation: Te= pn( ψiq ψqi)= pn[ ψ fiq( Lq L) iiq] (5) In the formula, Te is the electromagnetic torque; n is the number of pole pairs. Equations of motion: ωr J = T Bω T () e r L t In the formula, J is a moment of inertia( kg m ); T L is the loa torque( N m ), T e is the output torque( N m ); B is the viscous friction coefficient. B. The Basic rinciple of MSM Vector Control In the fiel oriente coorinates, MSM vector control ACADEMY UBLISHER oi:./jnw.8..99

2 JOURNAL OF NETWORKS, VOL. 8, NO., ARIL 95 simulates the DC motor torque control law, the current vector is ecompose into the excitation current component to prouce magnetic flux an the generate torque of the torque current component, the two current components are ajuste respectively, so that ecoupling control is realize to control torque component an flux component of MSM respectively [79]. Accoring to the same principle of magnetic potential an power, the coorinate transformation is mae to threephase voltage, current an flux for MSM. Stationary coorinate system of the threephase ABC transforms into q rotating coorinate system, stator current vector is ecompose into the rotor fiel oriente two mutually orthogonal current component, they are excitation component i an torque component i q of stator current []. Set i =,the component i q is controlle, it is equivalent to control the torque irectly. Electromagnetic torque T e an i q are linear relationship, so that the system has goo mechanical properties an ynamic performance. i q Regulating reference volume is given by the spee controller, the qaxis voltage components are output after current loop ajustment, which are u, u q. The component u α an u β are obtaine through antiarke transform for u an u q in the α β coorinate system. Accoring to the value size of u α an u β an SVWM space vector metho, the output of the vector control is obtaine to achieve the purpose of vector Control. It is i = vector control block iagram as shown in Figure. * osition osition Controller /s * ω r Spee ω r Spee Controller ω r i = ref ω r i i qref i q I I U q U Figure. MSM Vector Control Block Diagram III. SYSTEM DESIGN U α U β i β i α SVWM generator ark Transformation Anti ark Transformation Clark Transformation i a Optical encoer Inverter A. The Harware Structure of the Controller The controller system inclues a main power circuit, control circuit an the motor. The control loop is mainly compose by the master DS chip an sampling etection circuit. The most avance chip TMSF8 DS which frequency is 5MHz was use as core controller. The control chip is use wiely in the high precision servo control, variable frequency power supply an other areas, while it is the best choice of motor an igital control []. i b i c System harware block iagram is shown in Figure, the V AC is rectifie, an filter capacitor filter to obtain a smooth DC output, an finally the alternating current supply was obtaine for MSM through the inverter circuit to convert. C IO Interface Circuits Keyboar an Display Circuit I C S O I G I S S M T F 8 T N I D M W C D A E Q n to pi Ot a l o s i Detection an rotection Circuit Current Detection Spee an osition Detection Rectifier Circuit Figure. MSM Control System of the Block Diagram IM MSM The stator phase current signal etecte by hall current sensor is sent to DS through the ADC moule, it constitutes the current closeloop control system. The rotor spee an position signal etecte by optical encoer are sent to DS through the QE moule, it constitutes the spee an position control loop. In the DS, corresponing op conversion is mae applying the soft program for the etecte signal, SVWM pulse rives signal is generate which is require in the control. It rives the IM intelligent power moule through optoisolation circuit, controls the turnon an turnoff time of IGBT an generates the corresponing voltage signal which controls the motor running. When the system etects fault signal, it is transmit to the DS power protection input interrupt pins (DITNT) through the optoisolation circuit, so that the power protection interrupt signal is generate to turn off the channel WM signal output pulse signal achieving the protection of system failure. In aition, the DA converter, C connection an other external auxiliary circuits are realize through the DS's SI, SCI, an GIO interface. B. Main ower Circuit Design The system's main power circuit consists of a rectifier circuit, filter circuit an the IM moule. The rectifier circuit part uses singlephase uncontrolle rectifier moule GBJ5M. AC is rectifie DC, the maximum voltage is = V, GBJ5M rectifier moules are fully able to meet the requirements. The pressure of the filter capacitor is at least as 75V, so the paper selecte two µ f / 5V capacitors in parallel with a ecrease of the ESR of the capacitor, the pressure value is 5V, the capacitance is µ f. This paper inverter circuit part aopts IM S9, it integrates highvoltage power transistor rive circuit in their own internal, an owns builtin overvoltage, overcurrent an overheating fault etection circuit, so that it can ensure the safe operation an reliable operation for the controller. Its rate voltage is V, rate current is 5A for the ACADEMY UBLISHER

3 9 JOURNAL OF NETWORKS, VOL. 8, NO., ARIL S9, an the inverter output power is: = V I cosϕ (7) out out out In the formula, V is the output voltage rams out value; Iout is the output current rms value; cosϕ is the power factor. When inverter operates, taking into account the requirements of motor overloa, inverter takes power rating of.5 times margin, the power factor is.7 [], so the maximum output power of the inverter is: = =.KW (8) max It has the ability to rive KW motor. C. hase Current Detection Circuit The control loop in orer to achieve the current loop, spee loop an position loop three closeloop control, DS will etect the current signal, spee signal, an location of the signal after the program operation processing, Event Manager EVA an EVB prouce channel WM signal to control the inverter turnon an turnoff. MSM vector control system with i = control strategy must be timely etection the size of the stator phase current value. In this paper, TKC takes as closeloop hall current sensor. Motor using a Yshape connection can only etect two phase currents, shown in Figure, in orer to achieve the current closeloop control. 5V Uo OUT V GND O/ Ui 5 V R IN TKC 5 5 R C R LM58 5 R LM58 R R7 Figure. Current Sensing Circuit R8 LM58. BAV99 ADCINAI The system utilizes TMSF8 has highresolution of the AD converter, to improve the accuracy an timeliness of the current sampling. DS's ADC input voltage range is to.v, the hall current sensor output current is a bipolar signal, it nees convert the etecte current signal into the voltage signal through converter circuit, so that the DS can ientify the signal. The current sensor etects the current signal of the first through the RC filter, an then through a voltage follower, then is mae DC bias through the op amp circuit, finally a proportion of operations is mae, the output signal range from to.v is obtaine. Bias voltage of, the op amp circuit uses a highspee ual op amp chip LM58. Use switching ioe BAV99 as the voltage clamp circuit to prevent voltage excees.v. D. osition Detection Circuit osition etection is achieve by using the optical encoer, the article selecte the hybri optical encoer, its single ring pulse number is.signal output aopts ifferential river, It can reuce the common moe interference of the signal transmission. The rotor position etection circuit is shown as in Figure. U R C 5 5. R MM7HC. R 7HC R N7 R C Figure. Rotor osition Detection Circuit.. BAV99 7HC Accoring to U,V,W ege of the trigger signal to etermine the initial position of the rotor in which the motor is starte. Encoer output U,V,W signal after 7HC, output for the threeway interaction ifference of electrical angle, the with of 8 electrical angle of the square wave signal, then after the isolation of highspee optocouplern7,shaping the signal through the Schmitt trigger MM7HC, to ensure the accuracy of position etection. Finally, through the QE moule is input to TMSF8. E. Spee Detection Circuit Optical encoer output is sixway ifferential signals A ±,B ±,Z ±, its output voltage range is from to 5v, the signal nee to be converte by using the ifferential receiver. Rotor spee etection circuit is shown as in Figure 5. A A R R C R C C 5 C DS8 R 5. N7 R R7 C5 Figure 5. Spee Detection Circuit. 7HC. BAV99 In this paper, the encoer pulse signals are converte into a single output signal by DS8, an then isolate by the optocoupler N7, shaping the signal through the Schmitt triggers 7HC. Finally, the signals are input to TMSF8 through the QE moule. F.The Design of Limiting the Current Starting Circuit The auxiliary circuit of the system by limiting the current starting circuit, DC bus overcurrent protection circuit, voltage etection circuit, braking circuit, power circuit, chip voltage monitor circuit, the serial communication interface circuit an its peripheral circuits. Limit the current starting circuit in orer to prevent the starting current is too large, while amage to the brige rectifier, uring the motor starter. The main circuit will prouce a very high current when power is connecte, at this point relays no action, 5 V supply is not turne on, current through the thermostat flow into the filter capacitor, thermostat to play the role of limit the current. Delay in secons, normal both ens of the filter capacitor QE QE ACADEMY UBLISHER

4 JOURNAL OF NETWORKS, VOL. 8, NO., ARIL 97 voltage, DC bus current is reuce, at this time5 V power supply connecte, the normally open relay contact pull, the thermostat shortcircuit, en of the limit the current starting. Limit the current starting circuit shown in Figure. K DC R C R R A TLV7ID C R 5 C.V D ADC D D TC R C Figure 8. Voltage Detection Circuit Diagrams Figure. Limit the Current Starting Circuit G.DC Bus Overcurrent rotection Circuit When the DC bus current is too large, IM moule can easily be burne, therefore esigne a DC bus overcurrent protection circuit, Shown in Figure. In the filter circuit an IM moules in series one.ω sampling resistor, the overcurrent protection circuit to monitor the pressure rop across the sampling resistor. Overcurrent etection signal is active low, when the DC bus current is normal, the transistor Q5 is turne off, the comparator LM9 inverting input is groune, 5 V power input access the same phase, LM9 output invali high signal; When the DC bus overcurrent, transistor Q5 turns on, comparator LM9 output low flow signal through optocoupler to DINT pins. Immeiately cut off the WM signal output an LED alarm instructions after DS receive overcurrent signal. R Q R R C C LM9.V R7 DINT I. Dynamic Braking Circuit When the servo river brakes frequently with a large inertia loa, servo motor will in the power generation state, but rectifier part of the system is uncontrollable rectifier circuit, the energy can t be fe back into the gri, DC bus voltage of the system will rapily increase. It is easier to be amage for the energy storage capacitors, power moule, so the ynamic braking circuit must be ae for the servo rive system. The TMSF8 chip GIOA pins sens out the brake signal, first through optoisolation, an then through ioe NVIDT7 to be amplifie 5V level signal, it rives the power transistor Q to be turn on, the power is consume in the resistor R. When the DC bus voltage is less than v, the riven power transistor Q is turn off, the braking process is ene The brake circuit is shown as in Figure 9. C C GIOA R.V R NC N5 5 C C R R 5 Q MMDT7 DC D Q DC R D R C C Figure 7. DC Bus Overcurrent rotection Circuit H. Voltage Detection Circuit The DC bus voltage etection circuit uses a closeloop hall voltage sensor, the etecte voltage signal is connecte to voltage follower circuit through the TLV7 of precision op amp. It is sent into DS chip by the A/D converter. When the bus voltage is larger than 8V, the controller sens a brake signal. When the bus voltage is less than V, DS takes as uner voltage state, its principle is same as over voltage. The voltage etection circuit is shown as in Figure 8. Figure 9. Dynamic Braking Circuit J. ower Management Circuit C C TS77D 8 DS_RST 7 5 SENSE DS_RST Figure. ower Management Circuit C R R C5 C C.8V.V The circuit voltage is.v for TMSF8 peripheral interface, its core voltage is.8v. In the aper, power management chip TS77Dis selecte, output ACADEMY UBLISHER

5 98 JOURNAL OF NETWORKS, VOL. 8, NO., ARIL twoway power are.8v an.v, so that the DS chip can normal work. DS has ADC moule, the voltage output must istinguish the igital voltage an analog voltage, so the igital groun an analog groun are connecte by beas. The circuit is shown as in Figure. K. Serial Communication Interface Circuit TMSF8 chip has a serial communication interface (SCI) moule, the serial port is configure as RS port to connect with the C easy. Because the DS level an RS level cannot match, a external circuit must be constitute by using power level conversion chip MAXD to meet the communication functions between the control panel an C. MAXD uses a.v supply voltage, its external four small capacitor rise the voltage from V to 5V. The serial communication interface circuit is shown as in Figure. after the stage circuit electrical isolation, but also has a level conversion function. The IM moule fault etection circuit iagram is shown in Figure. M. Temperature etection protection circuit IM moule S9 controller uses normal working temperature oes not excee, the heat sink is not only to the esign of the controller, but also the esign temperature etection an protection circuit, to prevent overheating burne chip an other circuit. aper, the temperature change of the temperature sensor T55 etecting controller, the temperature sensor T55 is reflecte by the change in resistance to temperature change, the higher the temperature, the smaller the resistance of the temperature sensor T55.The typical o value of the temperature sensor T55: R(5 C)=5.KΩ..V C C C SCITXDA SCIRXDA SCITXDB SCIRXDB 9 VCC V V C 5 GND TIN ROUT TIN ROUT MAX TOUT RIN TOUT RIN C5 C J T55.V.V R.K R K C8 fault R 5.K Figure. Temperature Detection rotection Circuit DINT Figure. Communication Interface Circuit N. The Software Structure of the Controller Start L.IM moule fault etection circuit The initialization of the system clock.v The timer is initialize FO R K R K Q NN R C8 fault R 5.K DINT Initialize the system parameters The software moule initialization Timer overflow interrupt an capture interrupt enable Figure. Temperature Detection rotection Circuit This article uses the IM moule S9, internal integrate overvoltage, overcurrent, overheating protection function, IM moules work properly, the S9 No. pin fault etection signal output terminal of the high level of 5 V,NN type transistor C9 an optocoupler C8 in the conuction state, the optocoupler output of.v high. When the IM moule fails, the fault etection signal output terminal output current of ma, low pulse with of.8ms signal, the NN type transistor C9 are in the OFF state an optocoupler C8 output is low, that is, a fault signal is active low. The optocoupler use not only before an To etect the position of the rotor initialization N Interrupt latency N Figure. Main rogram Flow Chart Y Y Rotor initial position etection subroutine Interrupt service routine A complete software system shoul inclue function subroutine, system initialization proceure, the timer main interrupt program, position etection interrupt program an protection interrupt program. Software ACADEMY UBLISHER

6 JOURNAL OF NETWORKS, VOL. 8, NO., ARIL 99 mainly achieve SVWM control algorithm, the coorinate transformation, igitize I regulator an current / position signal etection, they are all implemente in the main interrupt program []. The first three o not nee to control the harware, the rest requires software an harware properly fit in orer to achieve accurate control effect. The introuction of interference in the signal etection will irectly affect the control performance of the system. After control system start plus power, the first nee to o is the initialization of system input an output moule classes an ata processing moule class, an system resources, an then is the etection of the initial position angle of the MSM. After get the initial position angle information of the rotor an then carry on backstage processing program, an wait for interrupt hanling signal is use to access the system subroutine in orer to control MSM []. The system main program flow chart is shown in Figure. IV. SIMULATION RESULTS Matlab/simulink can accurately establish MSM vector control system simulation moel which base on magnetic fiel orientation. Three closeloop control system control process: through position regulator seek the velocity comman value after position instruction value an feeback value compare; through velocity regulator get current (vector) size of the comman value after the spee instruction value an the spee feeback value [5]. Accoring to the current comman value an the actual position value calculate threephase instantaneous current comman value, the stator current is close to the comman value after the current close loop control. Current regulator output value through SVWM moule, output of WM wave controlle inverter moule, prouce the esire phase current supply MSM. MSM three closeloop vector control simulation moel system iagram as shown in figure 5. This paper chooses the rate spee of the motor is ra/s, pole number is, the position reference value is set to ra, the simulation time is set to.5s.the rotating spee response waveform is shown in Figure,can see motor noloa can quickly reach the maximum spee, after slight fluctuations stabilize rate spee in ra/s, when.s loa N m, spee fluctuate somewhat, but soon was stable in ra/s. When arrive at a set position ra, motor spee ecrease rapily, while unloa N m loa, uring escening process the spee is corresponing rapily, with slight fluctuations, finally spee stabilize in ra/s an parking at.5s. n(ra/s) t/s Figure. Response of Spee Torque an excitation component of current waveforms are shown in Figure 7, Torque an excitation component of the stator have fluctuation when the motor start an stop, when the motor operate stably,the fluctuation is small; At.s joine the loa, torque component corresponing rapily, operate stably after a greater fluctuation; the motor spee ecreases an eventually stop the rotation, uring the motor brake process the torque an the excitation component of current has a bigger wave motion, finally the two components are reuce to A. Figure 5. The Block Diagram of the Control System of MSM ACADEMY UBLISHER

7 JOURNAL OF NETWORKS, VOL. 8, NO., ARIL I Iq/A Figure 7. The Torque an the Excitation Component of Current Electromagnetic torque an loe torque waveforms are shown in Figure 8. t/s I Iq operation,.s ae loa, threephase current value rose rapily; when the spee rop suenly, an eventually reuce to r/s, the current of each phase of the stator, first there are small fluctuations, an then stabilize an, ultimately, the phase current values own to. By the simulation waveforms visible, motor starts fast, an can quickly an accurately track a given spee. In the case of loa increase, spee after shortterm volatility can track the given spee, the spee fluctuation is very small. In the ebugging system, the spee of the motor starter stop process curve shows that motor by the rate spee quickly arrive at the esignate location an is able to accurately locate parking. The control system can rapily reach steay state, overshoot, an steaystate error is very small, an the experimental results show that the controller esign is reasonable an has a goo ynamic an static performance. Te TL(N*m) t/s Figure 8. Electromagnetic Torque an Loe Torque We can see that electromagnetic torque of the motor change always aroun the loa torque; electromagnetic torque has greater fluctuating prouce starting torque as motor start, at.s joine N m, electromagnetic torque rapily achieve N m, motor spee ecreases an eventually stops rotating, electromagnetic torque rops rapily an prouce a reverse braking torque, eventually stabilizing at N m. I/A t/s Figure 9. Stator Current Waveform The threephase stator current waveform as shown in Figure 9, as can be seen from the graph, when starting the motor current has fluctuation; the current value is very small close to A when the motor unloae stable TL Te V. CONCLUSION This article use avance igital signal processing chip an esigne a MSM igital controller. By analyzing the moel an control strategy of MSM, ropose the main harware structure part an the software program of the MSM controller, an built a simulation moel of the controller. Through the simulation experimental stuy on MSM servo system startup, operation an parking, you can get the conclusion: the whole process of the system, spee is running smoothly, the torque ripple is small, small overshoot an precise positioning, an controller esigne reasonably an has goo ynamic an static performance. ACKNOWLEDGEMENTS The paper is supporte by Key rojects of Henan rovincial Department of Eucation Science an Technology Research (A7), Laboratory of Fun Colleges Control Engineering Key Disciplines of Henan rovince (KG), Science an Technology Research of China Coal Inustry Association (MTKJ7) an Dr. Founation of Henan olytechnic University uner Gran (B). REFERENCES [] Miao H, Zhenhua L, Design of Sensorless MSM Controllers Base on DS. Small & Special Electrical Machines,vol. 8, no., pp.5,. [] Wen D, Lin G, Deliang L, ing S, Moeling an Simulation of Vector Control System for ermanent Magnet Synchronous Motors. Micromotors,vol., no., pp.7, 9. [] Bin Chen, Hongzhen Yang, Liwen Wang, Single Neuron ID Control of Aircraft Deicing Fluis Rapi Heating System. Journal of Networks. vol. 8, no., pp.5,. [] Tengyue Mao, Zhengquan Xu, Rui Hou, Min eng, Efficient Satellite Scheuling Base on Improve Vector Evaluate Genetic Algorithm. Journal of Networks. Vol.7, no., ACADEMY UBLISHER

8 JOURNAL OF NETWORKS, VOL. 8, NO., ARIL 9 [5] Jianhong L, Yangzhong Z, The Design for a ermanent Magnet Synchronous Motor Servo Control System Base on DS. ower Electronics, vol., no., pp.798,. [] Xiaoli C, Linna H, The Design of Drives System for MSM Base on DS. ower Electronics, vol. 5, no., pp.57,. [7] Bingqiang L, Hui L, Direct Control of Current Vector for Surfacemounte ermanent Magnet Synchronous Motor. roceeings of the CSEE, vol., no., pp.889,. [8] Tiebing L, Chunjiang L, Yuejin Z, Huichen M, The Stuy of MSM Vector Control System Base on DS. Micromotors, vol., no., pp.8,. [9] Liu Yanping, Liu Shuhong, Wang Huajun. DS control implement of permanent magnet synchronous AC servo motor base on vector control. 9 IEEE International Conference on Mechatronics an Automation, pp. 887, 9. [] Hui Z, Chao L, The Research of Control Strategy for MSM Base on SVWM. Electrical Measurement & Instrumentation, vol., no. 7, pp.8, 9. [] Naiqing X, Jishen, Jian L, Servo Drive Control of MSM Research Base on IM. Control & Automation, vol. 7, no. 5, pp.55,. [] Junfeng J, Xuejuan T, Digital Vector Control System of ermanent Magnet Synchronous Motor Base on DS. Electric Machines & Control Application, vol. 7, no., pp.,. [] Yannan X, Research on Servo Vector Control System Base on TMSF8. Micromotors, vol., no., pp.777,. [] Junmei Guo,Yiwei Zhao, DS ractical Solutions for Motor Control Using DSController. IEEE International Conference on Networking an Digital Society, pp. 9,. [5] Murat Karabacak,Halil Ibrahim, Design, moelling an simulation of a new nonlinear an full aaptive backstepping spee tracking controller for uncertain MSM.Applie Mathenatical Moelling, vol. 7, no., pp.5,. Li Wankui, male, born in Xinyang City, Henan rovince, China, in August, 988. He is stuying at the college of Electrical Engineering an Automation, Henan olytechnic University, China, since. His research fiels are special motor rive, MSM control an motion control. He obtaine bachelor's egree in college of Electrical Engineering an Automation, Henan olytechnic University, China, in.his research works mainly engage in novel control theory research an the new control system evelopment of MSM.In recent years, he publishe one acaemic paper. Han Lili, female, born in uyang City, Henan rovince, China, in August, 987. She is a postgrauate stuent at Henan olytechnic University. Her research fiels are ermanent magnet synchronous motor control Kalman filter algorithm. Jun Zhu, male, born in Wulanchabu City, Inner Mongolia Autonomous Region, China, in October, 98. He obtaine H.D egree in college of Mechanical an Electrical Engineering, Inner Mongolia Agricultural University, China, in. His research fiels are special motor rive, nonlinear motor control an motion control. He has been working at Henan olytechnic University since, an is interesting in teaching an scientific research. He is a researcher of Special Electric Machines & Drives (SEMD) in Henan olytechnic University. His research works mainly engage in novel control theory research an the new control system evelopment of special motor. Dr. Zhu is a member of Henan rovince institute of special electric machine an rives. In recent years, he presie provincial an one country research projects, an publishe more than acaemic papers. He obtaine national invention patents, an provincial acaemic rewars. ACADEMY UBLISHER