* Question
| What is the role of the inverter? |
* Answer
| The frequency converter is a device that converts a commercial frequency power supply (50 Hz or 60 Hz) into an AC power source of various frequencies to realize variable speed operation of the motor, wherein the control circuit completes control of the main circuit, and the rectifier circuit converts the alternating current into direct current, and the middle of the direct currentThe circuit smoothes the output of the rectifier circuit,The frequency conversion technology was born in response to the need for stepless speed regulation of AC motors.Power electronics have experienced SCR (thyristor), GTO (gate turn-off thyristor), BJT (bipolar power transistor), MOSFET (metal oxide field effect transistor), SIT (static induction transistor), SITH (electrostatic induction thyristor), MGT (MOS Control Transistor), MCT (MOS Control Thyristor), IGBT (Insulated Gate Bipolar Crystal)In the 1980s, the PWM mode optimization problem as the core of the frequency conversion technology attracted people’s strong interest, and many optimization modes were obtained, among which the saddle-wave PWM mode was the best.
Since the second half of the 1980s, VVVF inverters from developed countries such as the United States, Japan, Germany and Britain have been put into the market and have been widely used.It can be divided into V/f control inverter, slip frequency control inverter and vector control inverter; according to the purpose classification, it can be divided into general inverter, high performance special inverter, high frequency inverter, single phase inverter andThree-phase inverters, etc.VVVF: Change voltage, change frequency CVCF: constant voltage, constant frequency.In order to generate a variable voltage and frequency, the device first converts the alternating current of the power source to direct current (DC).A frequency converter for motor control that changes both voltage and frequency. |
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