This classification covers inverters (frequency converters) that provide variable control of motor rotation speed and output in manufacturing sites. It includes general-purpose inverters, vector control inverters, and servo inverters that provide speed control, energy-saving operation, and soft start functions for three-phase induction motors. Used for drive control of pumps, fans, conveyors, machine tool spindles, and other equipment to achieve efficient production facility operation through power conversion. Distinguished from motor units and PLC control panels, this category specializes in inverter devices with frequency conversion functionality.