What causes abnormal temperature rise of power capacitors?

Abnormal temperature rise of power capacitors caused by poor ventilation conditions or prolonged overcurrent in the operating environment:

1. Unreasonable space design and ventilation device installation location, resulting in poor ventilation and heat dissipation;

2. Long term overvoltage operation leads to increased heating of capacitor overcurrent;

3. Overcurrent heating of capacitors may also be caused by high-order harmonics generated by rectification.

4. Aging of capacitor dielectric, insulation moisture, internal component failures, etc. can also cause abnormal temperature rise of capacitors.

Abnormal temperature rise in power capacitors can lead to high body temperature, further exacerbating the thermal aging of the internal insulation medium, resulting in a decrease in the insulation strength of the capacitor body, and even causing local discharge faults inside the capacitor body. The service life of power capacitors roughly follows the 8 ° C rule compared to their operating temperature, that is, after exceeding the design allowable operating temperature, the actual operating temperature of power capacitors is halved for every 8 ° L increase in service life.

So when choosing power capacitors, overcurrent, overvoltage, and temperature control protection devices should be selected to effectively avoid capacitor faults caused by abnormal temperature rise of power capacitors.