Modeling and Optimal Control of Modified Pulsewidth Modulation on Series Resonant-Based Dual Active Bridge

This article presents a numerical analysis and performance comparison of different modulation techniques on the series resonant dual active bridge (SR-DAB). The SR-DAB is a widely accepted dc-dc converter that provides bidirectional power flow and is utilized in numerous applications. However, it suffers from issues, such as high reactive power circulation and loss of soft switching, during switch turn-on at nonunity voltage gain of the converter. The modulation techniques employed predominantly affect the performance and efficiency of SR-DAB. Thus, detailed analysis and comparison of different modulation techniques, such as single phase shift, extended phase shift, and dual phase shift, are performed on SR-DAB. A modified pulsewidth modulation (M-PWM) technique with optimal control is proposed to enhance performance, such as extended soft switching and reduced reactive power circulation. The control based on minimum current trajectory (MCT) is implemented to optimize and achieve maximum efficiency of the M-PWM technique with SR-DAB. The numerical analysis and performance comparison are verified using simulation results. A prototype of 500 W is built, and experimental results are reported to verify the M-PWM with the MCT technique.