A novel ZCS back-to-back current source converter for high power applications

This paper focuses a novel Zero Current Switched (ZCS) back-to-back current source converter for high power applications. A single DC link auxiliary circuit with a new commutation scheme helps to achieve soft switching for rectifier, inverter side and auxiliary switches. Two different switching algorithm (namely, Type-I and Type-II) are proposed depending upon the relative switching instants of rectifier and inverter side devices. Type-II switching algorithm helps to reduce effective switching frequency of auxiliary circuit and maintains improved pulse accuracy over type-I switching counter-part. Design and analysis of the power circuit for 2MVA/4160V system, simulation results from a back-to-back current source converter are presented.