Working principle and function application of frequency converter

Frequency converter （Variable-frequency Drive,VFD） Is the application of frequency conversion technology and microelectronics technology , The power control equipment that controls the AC motor by changing the frequency of the motor's working power supply .

The frequency converter is mainly composed of rectifier （ AC to DC ）、 wave filtering 、 Inversion （ DC to AC ）、 brake unit 、 Drive unit 、 Detection unit, micro processing unit, etc . The frequency converter depends on the inside IGBT To adjust the voltage and frequency of the output power supply , Provide the required power supply voltage according to the actual needs of the motor , So as to save energy 、 The purpose of speed regulation , in addition , The frequency converter also has many protection functions , If it's over current 、 Overvoltage 、 Overload protection and so on .

The working principle of the frequency converter is to control the main circuit through the control circuit , The rectifier in the main circuit converts alternating current into direct current , The DC intermediate circuit smoothes and filters the DC current , The inverter finally converts the DC into the AC of the required frequency and voltage , Some frequency converters will also add CPU Etc , To perform the necessary torque calculation .

The frequency converter converts the power frequency into any frequency 、 An electrical device of AC power supply with arbitrary voltage , The use of frequency converter is mainly to adjust the power of motor 、 Realize the variable speed operation of the motor . The composition of frequency converter mainly includes control circuit and main circuit , The main circuit also includes rectifier, inverter and other components .

The power frequency power supply of frequency converter is generally 50Hz or 60Hz, Whether in the field of household or production , The frequency and voltage of power frequency power supply are constant . When the motor works with power frequency power supply, the power may decrease , Through the adjustment of frequency converter , The power loss can be reduced when the motor is adjusted .

The frequency converter adjusts the voltage and frequency of the power supply , To achieve energy saving 、 The purpose of speed regulation , Besides , The frequency converter also has many protection functions , If it's over current 、 Overvoltage 、 Overload protection and so on . With the continuous improvement of the requirements of industrial automation and the advocacy of energy conservation , The application of frequency converter is also more and more widely .

Frequency converters are mainly used in ： Variable frequency energy saving 、 Automation system 、 Improve the process level and product quality 、 Realize soft start of motor .