Frequency effect: 

 Integrated high-voltage power inverter transistor technology and electronic control technology, widely used. The role of the inverter AC power supply is to change the frequency and amplitude of the magnetic field and thus change its movement cycle, to the purpose of smoothing the control motor speed. The emergence of the drive, making the complicated simple speed control, inverter + AC squirrel-cage induction motor combination can replace most of the previous work done with the DC motor, reduce the volume, reduced the maintenance rate, the transmission technology into a new stage. 

 Inverter consists of: 

 Inverter is usually divided into 4 parts: rectifier unit, high-capacity capacitors, inverters and controllers. 

 □ rectifier unit to a fixed frequency alternating current is converted to direct current. 

 □ high-capacity storage capacitor after the conversion of electrical energy. 

 □ inverter power switching transistor array formed by the electronic switch, the DC into a different frequency, width and amplitude of the square wave. 

 □ controller program works by setting to control the output square wave amplitude and pulse width, the superposition approximation of the AC sine wave to drive AC motor.