Reactive Power Optimization Control for Bidirectional Dual-Tank Resonant DC–DC Converters for Fuel Cells Systems

Compared to the traditional LC-type dual active bridge (DAB) series resonant converter, the DAB series resonant converter with dual tanks has a larger power transmission range, wider voltage gain, and broader soft switching range. However, this new proposed converter has a larger reactive power than the traditional one, so its efficiency is affected. Therefore, the model of the reactive power is first derived, the control object is defined as the minimum reactive power, and then, a new control scheme for reactive power optimization based on function monotonicity is proposed in this article. At the same time, all switches operate with the zero voltage switching, so the efficiency of the converter is improved. At last, a 500-W prototype is built, and the simulation results and experimental results verify the feasibility of the optimal control scheme.