Single coupled-inductor dual output soft-switching DC-DC converters with improved cross-regulation and reduced components

Single inductor dual-output (SIDO) DC-DC converters are attractive in diverse applications such as renewable energy systems and electric vehicles, due to its favourable advantages of reduced magnetic core and high-power density. However, in conventional SIDO converters, severe cross-regulation problem is caused by the multiplex of inductor current, resulting in deteriorated dynamic performance. To alleviate the cross-regulation problem, a new family of dual-output DC-DC converters is proposed in this paper, which employs a coupled inductor to substitute the inductor in SIDO converters. The proposed converters can achieve improved dynamic performance while keeping the advantage of reduced magnetic core. Moreover, the number of semiconductor devices is also reduced in comparison with conventional SIDO converters, and soft-switching operation of switches is also achieved. Therefore, lower cost and higher power density are obtained. Topology derivation of proposed converters from conventional SIDO converters is firstly demonstrated in detail. After that, the operation principle, steady-state characteristics and small-signal model are provided. Finally, design example and experiment results are given to validate the merits of the proposed topology.