Power frequency power supply (50Hz or 60Hz) is converted into AC power supply with various frequencies to realize variable speed operation of the motor. The control circuit controls the main circuit, the rectifier circuit converts AC power into DC power, the DC intermediate circuit smoothes the output of the rectifier circuit, and the inverter circuit converts DC power into AC power.
For frequency converters that need a lot of operations, such as vector-controlled frequency converters, sometimes a CPU for torque calculation and some corresponding circuits are needed. Frequency conversion speed regulation is to achieve the purpose of speed regulation by changing the power supply frequency of motor stator winding.
The extended data converter is mainly composed of rectifier (AC to DC), filter, inverter (DC to AC), braking unit, driving unit, detection unit and microprocessor unit.
The inverter can adjust the voltage and frequency of the output power supply by switching the internal IGBT, and provide the required power supply voltage according to the actual needs of the motor, so as to achieve the purpose of energy saving and speed regulation. In addition, the inverter also has over-current, over-voltage, overload protection and other protection functions. With the continuous improvement of industrial automation, frequency converters have been widely used.
The typical inverter system diagram is shown below, which mainly includes operation panel, VFD controller, motor and other parts.
Wuxi echo electric co., ltd.