Frequency converter is the power supply (50Hz or 60Hz) into a variety of frequency ac power supply, in order to achieve the variable speed operation of the motor equipment.Among them, the control circuit completes the control of the main circuit, the rectifying circuit transforms the alternating current into the direct current, the dc intermediate circuit carries on the smooth filter to the rectifying circuit's output, and the inverter circuit reversely transforms the direct current into the alternating current (and the core control circuit realization: the process of ac-direct-alternating).And frequency conversion technology is in response to the need of ac motor stepless speed regulation and the birth
