Modified Chopper with Asymmetrical Control Strategy for High Power Applications

Abstract

- In this paper an asymmetrical duty cycle control strategy was proposed to the TPTL dc/dc converter. The modified converter remains all the advantages of original control strategy; meanwhile, soft-switching can be achieved using the energy stored in output filter inductance and leakage inductances of transformers (or resonant inductances).Three-phase three-level (TPTL) dc/dc converter has the advantages of lower voltage and current stress on switches, which is suitable for high power and high input voltage applications. Adopting a symmetrical control strategy, the ripple frequency of input and output current can be increased significantly, resulting in a reduced filter requirement. To further reduce the current stress on switches for higher power. The improved resonant converter features zero-voltage-switching (ZVS) realization under wide load range and higher conversion efficiency. The proposed concept can be implemented with five level topology using Matlab/simulink software.