Vector Control System Of Position Sensorless Permanent Magnet Synchronous Motor

At present, most of the permanent magnet synchronous motor driving systems adoptsthe open loop variable voltage variable frequency strategy, which shows unsatisfyingperformance of slow torque response, poor steady-state behavior and low control accuracy.The closed loop vector control strategy can achive great performance of improved torqueresponse, steady-state behavior and high control accuracy of the system. The positionsensorless permanent magnet synchronous motor vector control strategy, while retaining thegreat performance of the closed loop vector control strategy, can lower system cost, improvethe reliability and accuracy of the system and further expand the application of the permanentmagnet synchronous motor control system.This paper first discussed the different structures and characteristics of permanentmagnet synchronous motor and analyzed its mathematical model at different coordinatesbased on vector transformation. Then the vector control vector strategy of permanent magnetsynchronous motor was established and the principle and realization of the space vector PWMmethod was elaborated. After that, the simulation module of the permanent magnetsynchronous motor vector control system was built and its performance was verified.Based on the analyzation above, this paper introduced the realization of the positionsensorless permanent magnet synchronous motor vector control system. The design of thehardware system, based on IRMCF341, was consisted of the main circuit and the controlcircuit.The main circuit includes the design of the rectifying and filtering circuit and thepower drive circuit. The control circuit includes the design of the EEPROM circuit, serialcommunication circuit, power supply circuit, DC bus voltage sampling circuit and singleshunt current sampling circuit, in which the single shunt current sampling method wasthoroughly studied and adopted. The design of the software system includes the design of thesensorless vector control algorithm and the design of main program, timer initializationprogram, timer initialization interruption service program, MCE startup program, motorcontrol program for the host computer control of the motor.Based on the platform designed, this paper carried out the debugging of the positionsensorless permanent magnet synchronous motor vector control system and analyzed thewaveforms of phase current, motor speed, rotor flux, rotor angle and space vector PWM.The results show that this design meets the application requirement of the control system.