Loss Optimization Method Based on the Main Circuit of T-type SVPWM

Abstract

To reduce the switching loss of power devices and improve the efficiency, an effective method is to reduce the switching loss by optimizing the modulation strategy of the control algorithm. Traditionally, the amount of on-off times is used to qualitatively estimate the amount of switching losses, but the estimation error is large. In this paper, based on a T-type three-level topology, the 7-segment and 5-segment SVPWM strategies were analyzed theoretically, the calculation methods were set, and an experiment is carried out on a high-power frequency conversion system. It is proved that the reduction amount of switching losses of power devices is not only determined by the reduction amount of switching times under different modulation strategies.