3. Power Quality Improvement Methods on the Grid Side

This chapter delves into the challenges and solutions for improving power quality in electrolytic capacitorless Permanent Magnet Synchronous Motor (PMSM) drives. The focus is on addressing LC resonance issues that arise due to reduced DC-link capacitance, which deteriorates grid-side power quality. The chapter introduces two main perspectives for improving grid-side current quality: virtual admittance and inductor current control. It also explores resonance suppression methods for drives with low DC-link inductance. The text provides a detailed analysis of the impedance model of electrolytic capacitorless PMSM drives and presents experimental results that validate the effectiveness of the proposed methods. Additionally, it compares traditional damping control methods with novel approaches, highlighting the advantages of the latter in suppressing harmonics and improving overall power quality. The chapter concludes with a discussion on the practical implications and benefits of the proposed strategies for industrial applications.