High ambient temperature

In hot summer, the temperature in the switch room is as high as 48℃, the ventilation condition is poor and the ambient temperature is too high, which is one of the reasons for the capacitor explosion.

The voltage is extremely unstable

It can be seen from the formula QC=2πfCV2 that the reactive capacity of the capacitor is directly proportional to the square of the voltage. When the voltage decreases, the reactive capacity of the capacitor will decrease in direct proportion to the square of the voltage, that is, the capacity of the capacitor will not be fully utilized. When the working voltage rises, the temperature rise of the capacitor will increase, even destroy the thermal balance of the capacitor and make the capacitor explode.

The existence of harmonic current

Due to the use of nonlinear load in power system, a large number of harmonics are generated, which causes the waveform distortion of circuit voltage and current. The existence of harmonic current will often make the capacitor produce abnormal noise, which will lead to the capacitor expansion in serious cases.