Saudi Arabia Self-Healing Capacitors

What is self healing metallized capacitor?

Self- healing is the ability of a metallized capacitor to clear a fault area where a momentary short occurs due to dielectric breakdown under voltage. The conditions that lead to a fault vary. In the production of the dielectric film, contamination can occur or a process control problem can result in compromised dielectric strength.

Which dielectric has a low potential for self-healing?

PPS is an example of a dielectric which does not have high surface oxygen content and therefore has a very low potential for self-healing. The deposition thickness of the metallized electrode directly influences the self-healing characteristics of the capacitor.

What is self-healing for capacitors?

The intense heat generated by this arc causes the metallization in the vicinity of the arc to vaporise (figure 2). Simultaneously it re-insulates the electrodes and maintains the operation and integrity of the capacitor (figure 3).

What are the advantages of metallized capacitors?

Metallized capacitors offer the advantages of volume efficiency and self-healing. Self- healing is the ability of a metallized capacitor to clear a fault area where a momentary short occurs due to dielectric breakdown under voltage. The conditions that lead to a fault vary.

Can a metallized capacitor clear a fault?

The ability of the metallized capacitor to clear a fault is influenced by several factors. The type of dielectric influences the ability to clear. Dielectrics such as polycarbonate and polypropylene have high surface oxygen contents. This is an important factor since oxygen is necessary to vaporize or “burn-off” the electrode around the fault area.

What happens if a capacitor is operated at 60 arms?

If the capacitor is operated with 60 ARMS or at 90 0 C, the core temperature of the capacitor will exceed the maximum operating temperature. The excessive temperature will lead to decreased voltage strength and eventual voltage breakdown and shorting.