Research On Sensorless Control System Of PMSM Based On Dead-time Compensation

At the present time,the technical development of new energy electric vehicles has been paid more and more attention.In its core motor control technology,there are various types of control algorithms in large aspects,as well as algorithms about performance optimization in many small details.If Problems of these algorithms are left unsolved,serious consequences will be caused in some cases.This paper studies the two aspects of no position control and dead zone effect.Due to cost control and in order to meet the needs of harsh actual working conditions,motor algorithm for sensorless control was proposed and developed.This paper analyzes the mathematical implementation of two typical sensorless control schemes.Then use it as the basis for the design plan.In actual PWM inverter application,in order to avoid the situation that two power devices of a phase bridge arm are turned on and short-circuited at the same time,and the device is damaged,a delay time,or,a dead time,needs to be added to the two devices in a specific way.In addition to the effects of fundamental and harmonics waves on the system voltage,current,and torque,the dead zone effect also causes the problem of zero current clamping,which aggravates the current distortion,affects the normal operation of the system,and the effect of the traditional compensation scheme depended on current polarity detection is greatly deviated.In view of the above problems,this paper constructs an experimental platform with the help of simulink software.Then we measured the waveforms of the motor-related quantities with and without dead time,and verified the theoretical analysis of the effects of the dead-time effect on the motor control system in the article.An appropriate theoretical scheme based on observer technology is designed and the compensation algorithm is simulated.The simulation results show that the method proposed in this paper reduce the zero current clamping phenomenon and distortion of the voltage and current waveforms caused by the dead time effect.The pulsation of the torque and speed curve obtained from the simulation is also reduced,and it is also smoother.This shows that the dead-time compensation method proposed in this paper is feasible.Finally,the error of the theoretical position and the actual position is compared through the output angle simulation waveform.It is found that this positionless solution can better follow the angle,so that complete the verification of the overall algorithm.