Inverter energy saving is mainly reflected in the application of fans and pumps. In order to ensure the reliability of production, all kinds of production machinery have a certain surplus when they are designed with power drives. When the motor cannot run under full load, in addition to reaching the power drive requirements, the excess torque increases the consumption of active power, resulting in a waste of electrical energy. The traditional speed regulation method of fans, pumps and other equipment is to adjust the air supply and water supply by adjusting the opening and closing of the baffle and valve of the inlet or outlet. Its input power is large, and a large amount of energy is consumed in the blocking process of the baffle and valve. If the flow requirements are reduced, the requirements can be met by reducing the speed of the pump or fan when using frequency control.