Phase shift controlled modular DC/DC converter with input voltage auto balance ability

A novel phase shift controlled modular DC/DC converter is proposed in this paper by integrating the full-bridge converters and three-level flying-capacitor circuit. Due to the series connection of the full-bridge modules, the high switch voltage stress in the primary side is effectively reduced. Therefore, the low-voltage rated power devices can be employed to obtain the benefits of low conduction losses. Moreover, the voltage auto-balance ability among the modules is achieved by the inherent flying capacitor, which removes the additional possible active components or control loops. In additional, zero-voltage-switching (ZVS) performance for all the active switches can be provided by the phase shift control scheme, which can reduce the switching losses. The circuit operation and converter performance are analyzed in detail. Finally, the performance of the presented converter is verified by the simulation and experimental results from a 2kW prototype.