Topology Study of Advanced Co-Phase Traction Power Supply System Based on Multilevel Three-Phase to Single-Phase Converter

The single phase power frequency traction power supply system is widely used in electrified railways of China, which inevitably brings negative sequence problem, and slope stop accidents may occur when trains pass through the phase separation area due to the existence of electric phase separation. The Advanced co-phase traction power supply system based on multilevel three-phase to single-phase converter can effectively solve the above problems through three-phase-single-phase symmetrical transformation. Firstly, the existing multilevel three-phase to single phase converters for advanced co-phase traction power supply system are analyzed in terms of topology and operating characteristics, and concludes that the three-phase to single-phase converter based on the modular multilevel converter (MMC) structure has significant advantages, which is verified by simulation in PSCAD. Finally, under the background of high proportion of new energy sources connected to the power grid, a new energy hybrid multi-terminal advanced co-phase traction power supply system based on MMC is proposed. The research in this paper can provide reference for the development of advanced traction power supply system.