PMSM Sensorless Speed Control System Design

PMSM control system uses speed sensor to detect motor speed, but the speed sensor installation makes the motor internal system more complex and the price will be increased. Speed sensor measurement result is prone to error, because PMSM speed tends to be smaller or sudden disturbance. The production and energy cost of PMSM control system in industrial production needs to be reduced. Speed and current double closedloop control system of PMSM is established. The vector control method, which is a component of the direct axis, has zero current component, and the motor has no direct axis armature reaction.With the change of stator current, the torque can improve the performance of the system. Sigmoid function is used to instead the switching function,weakening the chattering effect. Digital filter is applied to enhance the real-time performance of the system, improve the accuracy and flexibility, speed up the processing speed and reduce production costs.The influence of the high frequency components on the angle estimation is reduced by using the phase locked loop structure. SVPWM method is used to control the amplitude of the motor voltage and to improve the stability of the system.Simulation result shows that the sliding mode observer system can reduce the influence of the environmental disturbance and other uncertainties. The chattering is obviously weakened, and the speed of the motor can be estimated accurately.PMSM speed sensorless control system is divided into many modules. VHDL is used to realize SVPWM and SMO.The simulation is carried out in Quartus II software environment. The program is downloaded to the FPGA test box for verification and debugging. Experimental result shows that the control system of PMSM without speed sensor can be operated simultaneously. The high harmonics of the load current can be reduced greatly, and the torque ripple decreases. The peripheral components of the system are cut down, and the transmission speed is improved. PMSM control system can run stably and high efficiently.