An Active Damping Method for IPMSM Drive with Small Film DC-Link Capacitor Based on Rectifier Side Current Reconstruction

The LC resonance generated by the grid side inductor and the dc-link capacitor is a significant concern for the interior permanent magnet synchronous motor (IPMSM) drives with small film capacitor, which degrades the grid side power quality such as grid side current harmonics and input power factor. In this paper, an active damping method based on the rectifier side current is proposed to deal with the concern. The circuit model of the drive has been established to investigate the LC resonance and the instability issue. Different feedback variables are analyzed in detail and the rectifier side current is chosen, which is consistent with the LC resonance component in the grid side current. Meanwhile, a rectifier side current reconstruction method is proposed without adding extra sensors or sampling circuit hardware. The grid current harmonics can be suppressed and the input power factor is further improved. Experiments on an IPMSM drive have been carried out to verify the effectiveness of the proposed method.