Adaptive Voltage Feedback Controllers on the Non-Salient Permanent Magnet Synchronous Machine

The voltage feedback controller used in the flux-weakening region has gained popularity in practical applications due to its standard control structure and robustness against deviations of machine parameters. However, due to that the voltage loop exhibits highly nonlinear behavior in the flux-weakening region, a constant control parameter lacks flexibility and normally requires more time for tuning to balance the stability and dynamics in the whole flux-weakening region. This paper analyzes the voltage loop in both motoring and generating modes for a non-salient permanent-magnet synchronous machine (PMSM). An adaptive control parameter method is proposed for the voltage feedback controller, which can not only ensure the stability in the whole-flux weakening range but also can be well applied to the machine with different characteristic current ratios. Finally, the effectiveness of the adaptive control parameter method is demonstrated by the experimental results.