A Simple Triple Phase Shift Control to Minimize Inductor RMS Current Maintaining ZVS for Dual Active Bridge Converter

This paper proposes a novel approach for triple phase shift control (TPS) of dual active bridge (DAB) converter using frequency domain-based fundamental harmonic analysis (FHA), which is more convenient and straightforward. The proposed algorithm features the calculation of optimal control points that offer minimum inductor RMS current while maintaining soft switching at different output power levels. The closed loop control architecture features a PI controller and two look-up tables, offering precise and efficient control. The PI controller controls the external phase shift ratio based on the desired output power level. The look-up tables control the internal phase shift ratios of the twin H-bridges to modify the shape of the AC inductor current. A 3 kW DAB converter with input and output voltage ratings of 280 V and 300 V respectively verifies the proposed TPS control algorithm. The results also verify the effectiveness of the closed loop control strategy for the proposed TPS control. The control scheme is implemented in MATLAB Simulink.