The compensation capacitor is connected to the phase power supply. When the capacitor is broken down, it will not cause a direct short circuit of the capacitor, but a transient gasification discharge. When other capacitors are broken down, it will cause a short circuit between phases.

The self-healing capacitor uses a single layer of polypropylene film as the medium and a thin layer of metal as the conductive electrode. When the applied voltage is too high, the electrical weakness of polypropylene film is broken down, the impedance of the breakdown point is obviously reduced, the current density is increased sharply, the metallized coating produces high heat, the metal conductor around the breakdown point evaporates rapidly, forming the blank area of the metal coating, and the breakdown point automatically recovers the insulation.

Therefore, this kind of automatic recovery capacitor is called self - Healing capacitor