An Adaptive Angle Error Compensator for IPMSMs With Periodic Loads in the Flux Weakening Region

When the load of a motor changes periodically with the mechanical angle, the speed also changes. There are obvious amplitude attenuation and phase shift in the high-frequency band of the phase-locked loop, resulting in the periodic angle error between the estimated angle and the real angle when the motor is in the high-speed flux weakening region. The periodic angle error easily leads to the deterioration of the flux weakening control performance, and causes greater speed and current fluctuations. In this article, an adaptive angle error compensator (AAEC) is proposed to reduce the angle error caused by the periodic load and improve the performance of the flux weakening control. In order to avoid the influence of the angle error direct-current drift in the speed dynamic process on the AAEC iteration, the switch mode AAEC (SMAAEC) is proposed to replace the AAEC. The experimental results show that in the flux weakening region, the SMAAEC can greatly reduce the fluctuations of the speed, angle error, and currents, and improve the steady-state performance of the controller.