Why does the low-voltage parallel self-healing capacitor make a buzzing sound when it is just running?

During the initial operation stage, the low-voltage parallel self-healing capacitor emits a "buzzing" sound, which is a common abnormal phenomenon in power system operation. This sound could either be a normal indication of vibration or could be a sign of potential faults. So, what causes the buzzing sound when the low-voltage parallel self-healing capacitor is just operating?

Ⅰ. Normal vibration phenomenon






II. Electrical Abnormal Factors

Partial discharge: A micro-discharge phenomenon occurring at the weak point of insulation.


Self-healing reaction: The energy release when defect points in the medium self-heal

III. Mechanical Structure Issues

Fixation loosening: The support frame was not fully tightened during installation.




IV. Environmental Impact Factors