Energy storage technology mainly refers to the storage of electrical energy. The stored energy can be used as emergency energy, or it can be used to store energy when the grid load is low, and output energy when the grid load is high, for peak shaving and valley filling, to mitigate grid fluctuations. On the energy storage equipment system, the high-voltage main DC relay is mainly used in the DC side, the DC switching of the battery and inverter. The general voltage range of 750-1200VDC, the current range of 100-400ADC. energy storage is mainly used in the field of photovoltaic and wind more widely.