Inverter is used in machinery, petroleum, chemical industry, metallurgy, mining, building materials, paper making, textile, printing and dyeing, cement plant, power plant, water supply company, plastic machinery plant, boiler drum, induced draft fan, central air conditioning system and other industries and equipment. Replacing backward speed regulation, rectifier speed regulation, DC speed regulation, slip speed regulation and manual control of manipulator, the flow rate, flow rate and pressure of liquid and gas are adjusted, and the effect is remarkable, and the power saving rate is as high as 20%-70%; At the same time, it has obvious benefits in improving equipment operation performance, prolonging equipment service life, improving product quality, reducing non-production delay time and reducing equipment operation and maintenance cost.