The fundamental purpose of the transducer was not to save energy, but to replace the DC drive, and to meet the requirements of process control. The technology of frequency converter is a mature and advanced technology in today's automation technology. It is the product of the high development of electric power technology, microelectronic technology and control technology. The main principle is: through microelectronic devices, power electronics and control technology, the AC power supply of motor stator through the diode rectifier into DC, then by IGBT inverter for AC power frequency and voltage are adjustable, the power drive motor and load.
       In the early 80s of last century, the development of variable frequency speed control technology, in line with the requirements of the development of industrial automation, creating a new era of intelligent motor. Change the old mode of general motors running only in constant speed mode, the motor and its load drag in the case without any changes that can be in accordance with the requirements of the production process to adjust the output speed, thereby reducing the power consumption of motor, to achieve efficient operation of the system. At present, it has been applied in electric power, metallurgy, petroleum, iron and steel, chemical industry, water supply and drainage and other industries. It has become one of the main development direction of modern power transmission technology.
        AC asynchronous motor power saving measures can be used in different ways of energy saving. In general, the more commonly used speed control methods are hydraulic coupler speed regulation, cascade speed control, electromagnetic speed control and frequency conversion speed of four. In contrast, the frequency conversion speed saving effect is remarkable, especially in the fan, water pump.