Substation compensation focuses on reactive power balance of power grid, and centralized compensation is carried out in substation. Compensation devices include shunt capacitors, synchronous cameras, static compensators, etc. The main purpose is to balance the reactive power of the power grid, improve the power factor of the power grid, improve the bus voltage of the terminal substation of the system, and compensate the reactive power loss of the main transformer and high-voltage transmission lines in the substation. These compensation devices are generally connected to the 10kV bus in the substation, so they have the advantages of simple management and convenient maintenance. Among them, the parallel capacitor banks are installed in the high and low voltage distribution lines for centralized compensation, the parallel compensation capacitors are installed in the low voltage side of the distribution transformer and the distribution panel of the user workshop for group compensation, and the parallel capacitors are installed in a single motor for local compensation. Installing reactive power compensation equipment can not only reduce power consumption and improve power factor, but also fully tap the potential of equipment to transmit power.