A zvs bidirectional inverting buck-boost converter using coupled inductors

Abstract

The bidirectional inverting buck-boost converter (BIBBC) has a simple structure and a wide voltage ratio. It can be used in the battery supercapacitor hybrid energy storage system (BSHESS) and the motor drive system. However, the traditional continuous conduction mode (CCM) BIBBC will have severe switching loss. The triangular current mode (TCM) BIBBC can reduce the switching loss, but it will increase core loss and filter capacitance. To solve these problems, this paper proposes a new zero voltage switching (ZVS) BIBBC using a coupled inductor. This ZVS BIBBC will provide ZVS conditions for both transistors whether in positive operation or negative operation. Meanwhile, this ZVS BIBBC has small core losses and filter capacitance, and can be used simply. Finally, experimental results obtained from these BIBBC experimental prototypes are presented to validate the soft-switching achieving and the efficiency improvement performance. Experimental results show that both transistors of the ZVS BIBBC achieve ZVS turn-on conditions. The efficiency of the ZVS BIBBC increased by up to 10 percent compared to the traditional CCM BIBBC at heave load, and by up to 1.5 percent compared to the TCM BIBBC at a light load.