Application of three-phase modular multilevel converter (MMC) in co-phase traction power supply system

Abstract

Co-phase traction power supply system was proposed for supplying the long-distance electrified railway without neutral sections. Active power conditioner (APC) is required in each substation, so that the traction loads are supplied without deteriorates the power quality at the grid side. The back-to-back converter was used to implement the APC in the past studies. However, bulky and costly coupling transformers have to be used. In this paper, the APC is implemented by using a three-phase modular multilevel con…