A dual-capacitor resonant circuit for adaptive resonant energy to be used in quasi-resonant ZCS dc-dc converters has been created. Specifically, the full-bridge (FB) boost-type dc-dc converters were developed for quasi-resonant ZCS operation and smooth current commutation by utilizing L-C resonance between leakage inductance of high frequency transformer and a resonant capacitor. In the new design, two capacitors (i.e. series-resonant and shunt-resonant) are implemented. The converter architecture is suitable for voltage step-up applications such as renewable energy integration with Medium-Voltage Direct Current (MVDC) grids and has substantial advantages over the existing types of resonant capacitor connections (within FB-ZCS converter family).