Research On Direct Torque Control Algorithm Of Permanent Magnet Synchronous Motor

In twenty-first Century,the new energy development has attracted much attention and invested extencively.The use of car sharing and the development of the motor will broad people's vision again,the permanent magnet synchronous motor(Permanent Magnet Synchronous Motor,PMSM)is widely used in the practical condition because of its fast dynamic response and steady state performance.In order to improve the overall performance of the motor,the direct torque control strategy(DTC)is applied to the PMSM,and the basis of the existing DTC algorithm will be improved.Based on the structure of motor body,the following research is carried out for the direct torque control algorithm problem in the paper:Firstly,studies during the introduction of the motor control strategy and the development status of PMSM at home and abroad shows that the performance of the motor,through the algorithm analysis and simulation modeling of the PMSM-DTC system,shows that it has fast response,strong anti-interference ability,and high stability.Secondly,considering the inverter relationship between time space vector and switching frequency from each cycles,starting switch voltage time by using carrier signal reduce the torque ripple,improve the control performance of the inverter by the designed torque regulator;To get better control result in a high strength load,first: using the zero vector,followed by using SVPWM and finally,using two order sliding mode control on the basis of SVPWM and the super twisting algorithm(Super-twisting)analysis of the flux and torque controller makes it applicable in traditional DTC system based on sliding mode control.Finally,according to the traditional DTC observation,stator resistance error of stator flux and electromagnetic torque at low speed due to the larger value changes will result in poor performance of the control system.Because of the resistance change of influence on stator flux and electromagnetic torque observer control system,a new perspective on the analysis of the stator has been made to solve these problems,using the variation of current to track stator resistance changes,reducing the stator flux and torque errors caused by the variation of the stator resistance due to system operation improved the system robustness.