DIRECT CURRENT POWER SUPPLY SYSTEM FOR URBAN RAIL TRANSIT CASCADED DIRECT-HANGING STATIONS

The present invention discloses a direct current power supply system for urban rail transit cascaded direct-hanging stations, belonging to the field of power electronic technologies. The power supply system includes a 110 kV high-voltage power grid, a 35 kV medium-voltage power grid, a cascaded H-bridge medium-voltage direct-hanging converter, a 650V-800V common direct current bus, a standby power supply and direct current electric loads. The cascaded H-bridge medium-voltage direct-hanging converter is formed by 3n modules in cascade, and each module is formed by an H-bridge converter and an isolated DC/DC converter connected in series. The present invention can replace an alternating current load power supply system based on a power frequency transformer, improve the efficiency and power density of the load power supply system of a subway station, reduce the no-load loss and extra cost introduced by the power frequency transformer, and achieve the purposes of energy saving, emission reduction and cost saving.