Frequency conversion energy saving is a power control device that uses the on-off function of power semiconductor devices to convert power frequency power supply to another frequency.

Protection function of frequency converter

The protection functions can be divided into the following two categories:

⑴ After detecting the abnormal state, automatically carry out correction actions, such as over-current stall prevention and regeneration over-voltage stall prevention.

⑵ Lock the PWM control signal of the power semiconductor device after detecting the abnormality to make the motor stop automatically. Such as over-current cut-off, regeneration over-voltage cut-off, semiconductor cooling fan overheating and instantaneous power failure protection.

How converter protection works

Why does the protection function of the frequency converter act when the clutch is used for continuous load?

When the clutch is used to connect the load, at the moment of connection, the motor changes sharply from the no-load state to the area with large slip, and the large current flowing causes the converter to trip due to overcurrent and cannot operate.

Frequency converter termination reason

In the same factory, large motors move together, and the frequency converter stops during operation. Why?

When the motor starts, it will flow the starting current corresponding to the capacity. The transformer at the stator side of the motor will produce a voltage drop. When the motor capacity is large, this voltage drop will also have a great impact. The frequency converter connected to the same transformer will make a judgment of undervoltage or instant stop. Therefore, sometimes the protection function (IPE) acts, causing the shutdown.