Current harmonics compensation strategy for vector-controlled SPMSM via enhanced adaptive notch filter

The article presents a harmonic voltage compensation strategy based on an enhanced adaptive notch filter (EANF) for eliminating dq-axis current ripples caused by current measurement errors (CMEs) in a current vector-controlled surface permanent magnet synchronous motor (SPMSM). Initially, a novel harmonic reference frame (HRF) is introduced to ensure harmonic currents are further decoupled from the fundamental current. And an EANF technique with a dynamic adaptive factor is developed, which is responsible for the performance of dynamic response and steady-state accuracy. In this way, the dq-axis harmonic currents in the HRF can be extracted quickly and accurately, and they are then compensated into the reference voltage supplied by the current regulator using a proportional-integral controller to achieve harmonic current suppression. Ultimately, the effectiveness of the method is validated by the SPMSM test platform. Experimental results indicate that the proposed CMEs compensation approach can considerably reduce the dq-axis currents and speed oscillations in comparison to the traditional method.