Hybrid Modulation-Based Semi Dual Active Half Bridge Converter With Coupled Inductor

A semi dual active half bridge (DAHB) converter with coupled inductor is proposed for unidirectional low-power applications. This topology comprises three active switches and a diode, reducing the number of required active switches compared with the conventional DAHB converters. Additionally, a coupled inductor is integrated to provide both isolation and energy transfer, eliminating the need for separate input and leakage inductors as well as the transformer. To optimize performance, a hybrid modulation strategy employing a seamless control law by combining pulse width modulation (PWM) and PWM plus phase shift (PPS) modes is also proposed. PWM mode allows the converter to have low current stress, while PPS mode enhances power transfer capability. The proposed control law ensures a seamless transition between the two modes and decouples control variables to simplify implementation. Furthermore, the converter is capable of achieving zero voltage switching on for active switches and zero current switching off for the diode across the full load range and a wide voltage range. Finally, the experimental prototype confirms the validity and effectiveness of the proposed topology and control strategy.