Series and parallel connection of ZVS-ZCS push-pull DC/DC converter module

This article presents a standardized modular converter that is an output unregulated push-pull DC/DC converter which performs zero voltage switching (ZVS) and zero current switching (ZCS). This modular converter has open-loop control. By way of the inherent voltage drop characteristic of the proposed modular converter, the input current of the modular converter increases as the output voltage decreases. A standardized modular converter can be connected either in series or in parallel to increase its rated capacity. The input current of each modular converter can autonomously distribute the load current uniformly, without any communication control signals originating in the modular converter, whether the standardized modular converter output is connected in series or in parallel. To verify the feasibility of the proposed circuit structure and modular connection, three 200W ZVS-ZCS push-pull DC/DC modular converter prototypes were developed with both in-series and in-parallel connections for the experimental verification of load sharing.