Current Measurement Offset Error Compensation Scheme Considering Saturation of Current Controller in SPMSM Drives

Abstract

A current measurement offset error compensation method for surface-mounted permanent magnet synchronous motor (SPMSM) drives that shows stable operating characteristics under the saturation of the current controller is proposed. For this purpose, an equivalent current control system including a synchronous frame proportional-integral (PI) current regulator with anti-windup control, current measurement offset errors, and the voltage model of SPMSM is derived to see the effect of the saturated output of the current regulator on the measured synchronous frame currents. The analysis results show that the saturated output of the current controller can interfere with the correction of the current measurement offset error. Based on this, we propose a current measurement offset error correction method that guarantees stable operation even under the saturation of the current regulator by reflecting the error between the output of the current controller and the actual output voltage to the current measurement offset error compensator. The effectiveness of the proposed method is verified through simulation tests and experiments.