Boost Control Strategy of Bidirectional Series Resonant Converter Based on Impedance Regulation and Charging of Resonant Network

The bidirectional series resonant converter (BSRC) is widely used in numerous DC/DC power conversion applications due to its advantages such as simple structure and topological symmetry. Traditional control strategies for BSRC include PFM, PWM, and phase-shift control, among others. However, under traditional control strategies, the maximum output gain of BSRC is limited to 1. A boost control strategy for BSRC that combines resonant network equivalent impedance regulation with resonant network charging is proposed in this paper. The equivalent impedance of the resonant network is adjusted by varying the operating frequency, while resonant network charging is achieved through a combination of phase shifting and PWM. Therefore, boost functionality of the SRC can be achieved without the need for additional auxiliary components. The effectiveness and practicality of the proposed control strategy were validated on a prototype with a rated power of 500W.