Loss balancing SVPWM for active NPC converters

This paper presents a novel loss balancing modulation method for more evenly distributing semiconductor losses in multilevel active neutral-point-clamped (ANPC) converters. The presented method is achieved by optimally utilizing the redundant switching states of space vector pulse width modulation (SVPWM) in ANPC converters. A comparison of the effect of losses distribution between the proposed loss balancing SVPWM (LB-SVPWM) method and the conventional phase-shifted PWM (PS-PWM) methods is carried out in simulation. The effectiveness of the presented LB-SVPWM method is also verified in ANPC converters based on all-SiC MOSFETs. The results show that the proposed method can distribute the device losses more evenly, especially for all-SiC based ANPC converters, which can in turn improve the output power capacity and switching frequency. In addition, with utilization of the introduced loss balancing SVPWM method in ANPC converters, 15% higher output voltage and lower harmonic distortion can be achieved compared to PS-PWM modulated ANPC converters.