A novel phase angle modulation strategy applied to dual active bridge converter in bidirectional energy storage system

Aiming at solving the problem of low efficiency of energy transmission in bidirectional energy storage system under the condition of large voltage difference between DC bus and battery, a novel phase angle modulation control strategy based on dual active bridge DC-DC converter is proposed in this paper. Under the control strategy, the energy stored in the inductor reaches the maximum during each switching cycle, and the energy transmission efficiency of the converter can be improved effectively under the same voltage level. At the same time, since the inductor current works in continuous mode, the soft-switching can be realized in a certain power range, and the current stress of the power devices can be reduced. Finally, the novel phase angle modulation strategy proposed in this paper is simulated and verified in simulink, when the output power is 5kW, the dual active bridge bidirectional DC-DC converter maintains a high conversion efficiency in charge and discharge mode, stable operation of the converter at constant voltage closed loop and constant current closed loop can be realized respectively.