Adaptive Virtual Admittance Reshaping-Based Resonance Suppression Strategy for PMSM Drives With Small DC-Link Capacitor

Active damping strategies can suppress the LC resonance for electrolytic capacitorless permanent magnet synchronous motor (PMSM) drives, yet it is difficult for the fixed damping coefficient to achieve optimal performance under different operating states. In this article, a novel adaptive virtual admittance reshaping-based resonance suppression strategy is proposed. The influence regularity of the virtual admittance amplitude and angle on the suppression capability of the LC resonance is analyzed. Furthermore, the relationship between the total harmonic distortion of the grid current and the harmonic factor of the dc-link current is established. According to the variation tendency of the harmonic factor, the optimal control of the grid current quality under different operating states can be realized by adaptively adjusting the virtual admittance amplitude. Aiming at the open-loop characteristics of the active damping strategy, an adaptive mechanism for the comprehensive adjustment of the time and admittance optimization steps is constructed. Experimental results validate the effectiveness of the proposed method in reduced dc-link capacitance PMSM drives.