"Overvoltage protection"in frequency converters is a commonly encountered issue during their operation.So,what causes overvoltage protection?
I have summarized four common scenarios:
1.Excessively High Input Voltage
When the input voltage exceeds the overvoltage protection threshold of the frequency converter,it triggers an overvoltage fault.This situation is relatively rare,as the protection threshold is typically set quite high,making it unlikely for standard input voltages to surpass it.
2.Fast Deceleration Time Under Heavy Load Without Braking Resistor or Unit
This is the most common cause of overvoltage protection.When the load is heavy,and no braking resistor or braking unit is installed,setting the deceleration time too short can lead to overvoltage issues.
3.Lightning Strikes
If lightning enters through the power line,it can generate an extremely high transient voltage,resulting in overvoltage protection activation.
4.Malfunction in the Hardware Detection Circuit
The DC bus voltage is sampled via resistors and processed by the MCU.If this part of the circuit malfunctions,it may cause inaccurate voltage readings,leading to false overvoltage protection triggers.