Decoupled Reference-Voltage-Based Active DC-Link Stabilization for PMSM Drives With Tight-Speed Regulation

Abstract

Reference-current-based active compensation techniques are widely used to actively damp the negative admittance effect associated with constant power loads in power electronic systems. These methods, however, yield strong coupling among the active compensator, speed, and current control dynamics when applied to motor drives. To overcome these difficulties, a new reference-voltage-based active compensator (RVC) is proposed to mitigate the negative admittance effect in permanent-magnet synchronous motor drives with tight-speed regulation. The proposed RVC suppresses the interaction dynamics between the compensator and motor drive dynamics in the low- and medium-frequency regions and maintains stability and effective damping performance along the whole loading trajectory of the motor drive. In addition, the proposed compensator has a very simple structure, and it can easily be augmented to existing motor drives with minimal interactions with existing drive control strategy and parameters. A theoretical comparative analysis and test results are provided to demonstrate the validity and effectiveness of the proposed technique.