Full Soft Switching Dual DC/DC Converter With Four-Quadrant Switch for Systems With Battery Energy Storage System

This paper describes topology and control algorithm for a two-stage bidirectional isolated converter with controlled semiconductors with the voltage-fed (VF) and current-fed (CF) stages. A four-quadrant bidirectional switch is connected in series with the transformer winding in the CF stage. For the energy transfer mode from the CF stage to the VF stage, a separated-commutation switching algorithm that provides a zero-current switching turn-off mode and an inductive snubber turn-on mode for the CF switches, and a zero-voltage-switching and capacitive snubber turn-off mode for the VF switches is described. Leakage inductance of the transformer is used as an inductive snubber. The influence of resonant phenomena on the VF transistors snubber switching-off process is taken into account. The topology is proposed for high power battery energy storage systems. The proposed ideas are verified with simulations in MATLAB.