Symmetrical Nine-Phase Drives with a Single Neutral-Point: Common-Mode Voltage Analysis and Reduction

Power converters generate switching common mode voltage (CMV) through the pulse width modulation (PWM). Several problems occur in drive systems due to generated CMV. These can be dangerous insulation and bearings of electric machine windings. In recent years, many methods have been developed reduce CMV multiphase machines. Symmetrical nine-phase machines with single-neutral are considered this paper. case, conventional PWM uses eight active vectors different magnitudes combination two zero states a cycle, generates maximum This paper proposes schemes such system. The first scheme is called state (AZS). It replaces suitable opposite vectors. second ten large during SVM-10L. Compared strategies, AZS reduces peak by 22.2%, SVM-10L 88.8%. Moreover, presents carrier-based implementation proposed simplify implementation. assessed using simulations experimental studies for an induction motor load under case studies.