The Generation Mechanism and Elimination Strategy of Narrow- and Error-Pulse for Cascaded H-Bridge NL-PWM Modulation

There is a wide application prospect of Nearest level pulse width modulation (NL-PWM) in cascaded H-bridge (CHB) converter, however, it will produce narrow- and error-pulse the process implementation, which has negative impact on CHB efficiency, output voltage quality safe operation power devices. In this paper, NL-PWM strategy improved based round function to solve narrow traditional NL-PWM, step wave delay update proposed NL-PWM. This paper analyzes basic principle its ability avoid device, shows harmonic characteristics generation mechanism error pulse, calculates caused by strategy. The correctness theoretical analysis effectiveness method are verified simulation experiment. research that can effectively prevent while maintaining good characteristics, little