High-power multi-unit grid-connected rectifier for ship and rail transit power supply system

The invention discloses a high-power multi-unit grid-connected rectifier for a ship and rail transit power supply system, which comprises a first power supply circuit, a second power supply circuit, a third power supply circuit, a fourth power supply circuit, a fifth power supply circuit and a sixth power supply circuit, the system is formed by sequentially connecting an AC looped network power supply line 2, an incoming line control circuit, a second rectifier unit and an outgoing line control circuit. The third power supply circuit is formed by sequentially connecting an alternating current looped network power supply line I, an alternating current looped network power supply line II, an interlocking circuit, an incoming line control circuit, a third rectifier unit and an outgoing line control circuit; and the input end of the third rectifier unit is connected to the alternating-current looped network power supply line I and the alternating-current looped network power supply line II through the incoming li