Analysis and Design of a Nonisolated Bidirectional DC-DC Converter Based on CLC Network

This article proposes a nonisolated bidirectional dc-dc converter based on the π type resonant network for renewable energy sources. The circuit consists of a front-stage boost inverter, a CLC resonant network and a poststage voltage doubled rectifier. The proposed converter has simple structure and smaller volume without conventional transformer, easier to achieve modularity and integration. Under bidirectional power flow, the switches can achieve zero voltage turn-ON and the rectifier diodes can achieve zero current turn-OFF with the wide load range. In this article, the operation modes, output power characteristics, soft-switching conditions, and the optimization design of the circuit are analyzed. A 200 W prototype based on GaN device is implemented and tested to verify validity of the proposed converter. The prototype can achieve a peak efficiency 95.4% in boost mode and 94.1% in buck mode.