A New Modulation Strategy to Operate Bidirectional Resonant Converter Under Extended Input Range

Conventional bidirectional resonant converters can transfer the power in both forward and backward directions, but their usage is limited due to a narrow input voltage range. In this paper, we propose a new modulation strategy to operate the bidirectional resonant converter under the extended input voltage range. In the forward direction, the converter operates as a PWM resonant boost converter. In the backward direction, it operates as a pulse-width-modulation (PWM) resonant buck converter. The use of bidirectional switch enables the circuit operate in both the PWM resonant boost converter and the PWM resonant buck converter. The proposed converter achieves the wide input voltage range with a small number of power components. At 250-415 V, 1.65 kW/400 V prototype of the proposed converter has been built and tested to demonstrate its circuit design.