Simplified Closed-Form Optimized Trajectories Control for a Dual Active Bridge Converter with ZVS Implementation over Whole Domain

A dual active bridge converter is widely used in electric vehicle charging systems and other fields for its excellent features. Despite the diversity of relevant studies on the triple-phase-shift (TPS) modulation, the existing investigations fail in the zero-voltage-switching (ZVS) implementation over the whole voltage and load domains, especially in the transition process between different modes. To address the current state of research, the magnetic current is introduced to bridge the ZVS gap between different modes in this article. A simpler method of the acceptable maximal magnetic inductance design in view of the current stress and the transformer's turns ratio is presented. Afterward, the evaluation method of system efficiency over the full voltage range is raised. Most critically, the simplified optimal control trajectories considering the impact of the magnetic current are proposed for the first time for the TPS modulation, eliminating the nonmonotonicity and leapfrogging of the control variables. Compared with the existing works, the method proposed in this article accomplishes ZVS over the whole domain, thereby reducing potential electromagnetic interference and enhancing the efficiency. Eventually, the proposed method is verified by a 1.0-kW prototype.