Multiphase DC-DC Converters Using a Boost-Half-Bridge Cell for High-Voltage and High-Power Applications

In this paper, multiphase dc-dc converters are proposed for high-voltage and high-power applications. A generalized converter is configured such that the boost-half-bridge (BHB) cells and voltage doublers are connected in parallel or in series to increase the output voltage and/or the output power. In addition to reduced device voltage and current ratings by the connection, the proposed converter has the following features: high-step-up voltage gain with significantly reduced transformer turn ratio, low-input current ripple due to interleaving effect, zero-voltage switching turn-ON of switches and zero-current switching turn-OFF of diodes, no additional clamping and start-up circuits required, high-component availability and easy thermal distribution due to the use of multiple small components, and flexibility in device selection resulting in optimized design. A design guideline of determining the optimum circuit configuration for given output voltage and power level is presented. Experimental results are also provided to validate the proposed concept.