Triple Phase Shift Modulation Scheme of DAB Converter with LCL Resonant Tank

In this article, an optimized triple-phase shift (TPS) modulation scheme is proposed for the dual active bridge (DAB) converter with an inductor-capacitor-inductor (LCL) resonant tank. By using the fundamental harmonic analysis (FHA), the working modes and the conduction loss are analyzed. The conduction loss is associated with the equivalent resistance of the components and the voltage conversion ratio. On the premise of the zero-voltage-switching (ZVS), the control scheme for optimizing the conduction loss is proposed with three degrees of freedom. The control law and the closed-loop control are analyzed for bidirectional power flow. Furthermore, the conduction loss is analyzed and compared with the previous dualphase shift (DPS) control strategies. It demonstrates the lower conduction loss in the optimized TPS modulation scheme. Finally, the performance of the control strategy is verified by a 1kW experimental prototype.