The General Carrier-based PWM Implementation based on Space Vector Analysis for Three-phase Three-level T-type NPC Inverter

The three-phase three-level T-type NPC (3LT2NPC) inverter is a good alternative to conventional NPC inverter due to it can be specified as the elimination of the diode requirement. This paper comprehensively evaluates the general carrier-based PWM (CBPWM) schemes on 3LT2NPC, regarding switching loss, neutral point balancing and harmonic distortion. The analysis of the proposed CBPWM method is based on the space vector analysis approach, where the relationship between CBPWM and space vector pulse width modulation (SVPWM) methods is described. Different CBPWM methods are built according to the distribution of zero vectors and redundant small vectors in the switching pattern of the SVPWM method. In this paper, a prototype of 3LT2NPC is built and tested, where both of SiC and Si Mosfet are used. The simulation and experimental results are provided to validate the feasibility of the proposed method.