A Phase-Clamped Proportional Duty Decoupled SVPWM Technique for a Four-Level Open-End Winding Induction Motor Drive

A dual two-level inverter fed an open-end winding induction motor (OEW-IM) can provide four-level inversion if the inverter's DC-link voltages are in a 2:1 ratio. Centre Spaced Decoupled Space Vector Pulse Width Modulation (CSDSVPWM) techniques were proposed for this drive to avoid the problem of overcharging the lower DC-link capacitor voltage. In this paper, a Phase Clamped Decoupled Proportional Duty SVPWM (PCDPD_SVPWM) technique is proposed for this drive, wherein the null vector combination is placed at the extreme edge of the sampling time period. This PWM technique clamps one phase of each inverter, lowering the switching frequency and, hence, the switching power loss. The motor phase voltage and current spectral performance are evaluated for the drive and compared between the proposed PCDPD-SVPWM and CSDSVPWM techniques.