Which internal filling material is better for power compensation capacitors?

Power compensation capacitors are widely used in industrial, commercial, and residential sectors to improve system power factor and reduce losses. Their performance, lifespan, and safety depend not only on their external structure and electrical characteristics but also on the selection of internal filling materials. So, what are the criteria for selecting internal filling materials for power compensation capacitors?

 

I. Basic requirements for selecting internal filling materials for capacitors:

 

1.High electrical insulation: The filling material must possess excellent electrical insulation properties to ensure that internal electrical faults do not occur.

 

2.Good thermal conductivity: Capacitors generate a certain amount of heat during operation. The filling material must have sufficient thermal conductivity to aid in heat dissipation and prevent overheating.

 

3.Corrosion resistance and anti-aging properties: Power compensation capacitors are often exposed to harsh environments. Therefore, the filling material must be corrosion-resistant to extend the equipment's service life.

 

II. Common types of filling materials for power compensation capacitors:

 

1.Oil-impregnated paper or oil-impregnated polyester film
Oil-impregnated paper and oil-impregnated polyester film are traditional filling materials for power compensation capacitors and are widely used in high-voltage capacitors. Their main characteristics include excellent electrical insulation and good thermal stability. The oil offers outstanding insulation performance, effectively preventing internal electrical faults such as flashovers.

 

2.Dry filling materials
Dry capacitor fillings generally refer to solid insulating materials (such as epoxy resin, polyester film, etc.) used as internal filling materials. This type of capacitor has a relatively simple structure and contains no oil, thereby avoiding issues like oil leakage or contamination.

 

3.Polypropylene film
As a new type of capacitor filling material, polypropylene film has gained widespread application in high-frequency, high-power scenarios in recent years. Polypropylene film exhibits high electrical insulation and thermal stability, along with a low dielectric constant, enabling it to maintain high performance under high-frequency currents.