There are many types of inverters, which can be divided into voltage-type and current-type inverters based on the working method of the main circuit. According to the switching mode, they can be categorized into PAM-controlled inverters, high-frequency PAM-controlled inverters, and others. Based on their working principle, they include V/F controlled inverters, slip control inverters, vector control inverters, and more. Classified by application, they are general-purpose inverters, high-performance inverters, high-frequency inverters, single-phase inverters, and three-phase inverters.

恒压恒频。The alternating current (AC) power used in each country, whether for household or industrial use, typically operates at 400V/50Hz or 200V/60Hz/50Hz. Generally, the device that converts a constant voltage and frequency AC power to a variable voltage or frequency AC power is called a "variable frequency drive" (VFD). To produce variable voltage and frequency, the device first converts the AC power from the source to direct current (DC). VFDs used for controlling motors can alter both voltage and frequency.