An Adaptive-Frequency Harmonic Suppression Strategy Based on Vector Reconstruction for Current Measurement Error of PMSM Drives

The errors of gain and offset caused by the current sensor measurement can lead to the first and second harmonics in dq-axis currents of the permanent magnet synchronous motor (PMSM) drives. An adaptive-frequency harmonic suppression strategy based on the vector reconstruction for current measurement error is proposed. The dq-axis current vector is recoordinate transformed using the division-frequency position as the transformation matrix angle. Thus, the frequency of the fundamental component can be decoupled from that of the harmonics in the current vector. In this way, the single-frequency harmonic suppressor can be established in the reconstructed coordinate frame. The current vector error is converged by adaptively adjusting the filtering weight and frequency so as to eliminate the harmonics. In view of the change of fundamental frequency, the variable step of the convergence is used to obtain the ideal filtering effect at different speeds and reduce the negative impact of current sensor measurement errors. The effectiveness of the proposed method is verified on the 11.7-kW PMSM drive platform.