Inverter is a device that converts power frequency power supply (50Hz or 60Hz) into AC power supply with various frequencies to realize variable speed operation of 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.

Function of frequency converter Direct function of frequency converter:

1. By changing the voltage and frequency of the motor, the speed of the motor can be adjusted steplessly.

2, soft start energy saving, power factor compensation energy saving.

Indirect function of frequency converter:

1, save energy (electricity). The traditional speed regulation method of fans, pumps and other equipment is to adjust the air supply and water supply by adjusting the opening of inlet or outlet baffles and valves, which has a large input power and consumes a lot of energy in the process of intercepting baffles and valves. When variable frequency speed regulation is adopted, if the flow requirement is reduced, the requirement can be met by reducing the speed of pump or fan, and the power consumption can be reduced.

2. Improve the automation of production equipment. At present, there are many inverter brands.

Inverter wiring diagram

Working principle of frequency converter The main circuit is the power conversion part that provides voltage regulation and frequency modulation power supply for asynchronous motor. The main circuit of the frequency converter can be roughly divided into two types: the voltage type is a frequency converter that converts the DC of the voltage source into alternating current, and the filtering of the DC loop is a capacitor. Current mode is a frequency converter that converts DC of current source into AC, and its DC loop filter is inductance. It consists of three parts: rectifier for converting power frequency power supply into DC power, smoothing circuit for absorbing voltage pulsation generated by converter and inverter,