5. Motor Side Beat Phenomenon Suppression Method

This chapter delves into the motor side beat phenomenon in electrolytic capacitorless drives, focusing on the significant fluctuation in DC-link voltage that results in additional harmonics in the motor current. The interaction between the fundamental component and harmonics of the motor current produces the beat phenomenon, increasing operating noise. The text analyzes current harmonics caused by DC-link voltage fluctuations and the influence of DC-link voltage sampling delay. It proposes beat suppression methods based on delay compensation and impedance reshaping to improve motor operation quality. The chapter also explores the beat phenomenon caused by the interaction of harmonics and fundamental currents, providing a detailed analysis of the beat frequency phenomenon under different ratios of harmonic and fundamental currents. Experimental results demonstrate the effectiveness of the proposed strategies in suppressing the beat phenomenon and improving power quality on the motor side.