Design of a current controller for symmetrical six‐phase fault‐tolerant PMSM under fault conditions

Abstract

To achieve the fault-tolerant operation of motor drives, many control algorithms have been proposed. Among them, it is more flexible and intuitive to find solutions to phase current at phase coordinate. Then it is necessary to track the given phase current. Up to now, several current controllers have been proposed. A hysteresis controller suffers from the drawback of the variable switching frequency. Proportional–integral control cannot track ac signals with zero error. As to the proportional resonant controller, its performance is highly dependent on the accuracy of motor speed detection. Considering this, a current controller is based on the adaptive filter. The adaptive filer is worked as the current controller by adjusting its structure, in which the motor model is extra introduced. The controller updates the tap weight in each control cycle until it outputs the optimal voltage to track the given phase current. Besides, the adaptive algorithm is improved by adding a feedforward term to gain a higher dynamic response. Moreover, to ensure the stability of the controller, the control parameter selection principles are analysed and acquired accordingly. Finally, several groups of experiments are conducted. The experiment results coincide with the analysis.