What is the working principle of frequency converter?

When the frequency converter is working, the control unit controls the main circuit, and the rectifier unit converts alternating current into direct current. Then it combs the direct current and outputs smooth filtering. Finally, the inverter converts the direct current back into controllable alternating current. Through this series of operations, the speed can be adjusted. At that time, the motor can output the amount of electricity it needs to avoid waste.

Let’s take a look at the expression of the synchronous speed of the AC motor:


in this expression

N: speed of asynchronous motor;

F: frequency of asynchronous motor;

S: motor slip;

P: Number of motor pole pairs.

From this formula, we can see that the rotational speed and frequency are directly proportional. The rotational speed of the motor can be adjusted by changing the frequency. If the frequency is in the range of 0-50Hz, the rotational speed has a wide range of adjustment. The frequency converter can adjust the power frequency of the motor to achieve speed regulation. This speed regulation method is highly efficient and has good performance, which is particularly ideal.