Comprehensive study of fast load modulation with volt-second balance in a dual-active-bridge converter

The procedure of load transition in a dual-active-bridge converter is expected to be fast and spike free. To achieve such a goal, the total required adjustment of phase-shift angles should be assigned to different switch arms properly. This study discusses all possible combinations of two switch arms and their related phase-shifts, which could result in several different solutions. By forcing a zero algebraic variation of the volt-second product, all solutions can keep the volt-second balance of the power inductor so that no risk of magnetic saturation in the transient state exists. The possibility of temporal overshoot current can be checked by verifying the monotonicity of the intermediate volt-second product. A comparison of all solutions is made to give a suggestion for their feasibility. Experimental tests are included at last which validated the theoretical analysis.