基于改进自抗扰控制的共直流母线开绕组永磁同步电机转矩脉动抑制策略

The open-end winding permanent magnet synchronous motor (OW-PMSM)with common DC bus can generate zero-sequence current (ZSC) due to the existence of the zero-sequence path, which can reduce the system efficiency and produce the torque ripple. The traditional ZSC suppression based on closed-loop control and modified modulation method has limited modulation range, thus cannot make full use of the speed range of dual-inverter system. Moreover, considering the cross coupling and dead-time, the ZSC cannot be completely eliminated. In order to suppress the torque ripple caused by the interaction between the ZSC and the third-harmonic back-EMF, a torque ripple suppression method based on modified active disturbance rejection control (ADRC) is proposed. Torque ripple is regarded as a part of the disturbance and estimated by a general-integral extended state observer (GI-ESO). Then a control law based on ADRC is designed to compensate the torque ripple. This method can effectively suppress the torque ripple generated by the ZSC and the third-harmonic back-EMF, especially with the high modulation ratio, so constant-torque speed range was extended. The proposed method is verified on an OW-PMSM drive platform through experimental tests.