Abstract: With the development of power electronics, microelectronics, and large-scale integrated circuits, variable frequency speed control is increasingly being adopted in industry. Keywords : frequency converter; AC; installation and testing. In human scientific exploration and production activities, instruments and meters have gradually formed a specialized discipline and a specialized industry. They support technological progress, provide experimental and observational means for scientific exploration in many fields, and provide necessary technical guarantees for orderly production activities and normal social life. This change is an important symbol of civilizational progress and a significant characteristic of the scientification of human labor. In recent years, with the development of power electronics, microelectronics, and large-scale integrated circuits, the emergence of new discoveries in natural sciences, the appearance of new inventions in engineering technology, improvements in production processes, and the reduction in the price of power semiconductor devices, variable frequency speed control is increasingly being adopted in industry. A frequency converter is a control device that uses the switching action of power semiconductor devices to convert power frequency power into electrical energy of another frequency. The frequency converters we use now mainly adopt an AC-DC-AC method (VVVF frequency conversion or vector control frequency conversion), first converting the power frequency AC power into DC power through a rectifier, and then converting the DC power into AC power with controllable frequency and voltage to supply the motor. A frequency converter's circuit generally consists of four parts: rectification, intermediate DC link, inversion, and control. The rectification section is a three-phase bridge uncontrolled rectifier, the inversion section is an IGBT three-phase bridge inverter with a PWM waveform output, and the intermediate DC link serves for filtering, DC energy storage, and reactive power buffering. [b][align=center]For more details, please click: A Brief Discussion on the Use of Frequency Converters[/align][/b]