Taking the section between Dengjiashan Substation and Liaojiatian section post power supply on Changsha-Kunming High Speed Railway as the research object,this paper establishes a all-parallel AT power supply system simulation model for high-speed railway with PSCAD/EMTDC component to set relevant parameters and conducts simulation calculation of various short circuit faults of substation and traction network based on equivalent calculation according to the actual connection mode and system parameters. The a...