Adaptive Stability Control Strategy for Electrolytic Capacitor-less Permanent Magnet Motor Drives

The slim film capacitor driving mode can prolong the operating life of the PMSM system and reduce the system volume. However, the small DC-link capacitor and the grid-side filter inductor are prone to LC resonance. Many stability control methods have been investigated, but they cannot work well under the situation of the grid impedance change. An adaptive stability control strategy is proposed to improve the power quality of the grid side for the electrolytic capacitor-less motor drive in this paper. Through the analysis of the phenomenon of the LC resonance on the grid side, the active damping control strategy based on DC-link voltage feedback is designed with the detection of the THD of the grid current. and the control parameters are adaptively changed. Then, the harmonics of the gird currents can be suppressed effectively. Finally, the simulation results verify the feasibility of the strategy.