A power converter is an electrical device that changes the voltage, frequency, number of phases, and other electrical quantities or characteristics of the power system; early technologies used rotary converters, and they were used after power electronics technology matured. Instead, it is called a static inverter made of thyristor (electronic valve) circuit control technology. The name is based on the mechanical classification of motors into rotating motors and stationary motors.
Rectifiers (rectifiers), inverters (inverters), choppers (choppers) and variable frequency drives (VFDs) are all types of inverters. Among them, Inverter is also used as a product name in Japan, and its function is equivalent to VFD.