DC electric vehicle charging station, commonly known as "fast charging", is a power supply device that is fixed outside the electric vehicle, connected to the AC power grid, and can provide DC power for the power battery of the off-board electric vehicle. The input voltage of the DC charging pile adopts three-phase four-wire AC380V±15%, the frequency is 50Hz, and the output is adjustable direct current, which directly charges the power battery of the electric vehicle. Since the DC charging pile adopts three-phase four-wire power supply, it can provide sufficient power, and the output voltage and current adjustment range is large, which can realize the requirements of fast charging.