What fill medium makes low-voltage power capacitors more durable

The durability of low-voltage power capacitors is closely related to their fill medium. Common capacitor fill media include different types such as oil, solid, and gas, and their durability is closely linked to factors like environmental conditions, operating temperature, load, and voltage fluctuations.

Here are several common fill media for capacitors and their durability characteristics:

 

1. Oil-immersed Capacitors

Characteristics: Traditional oil-immersed capacitors use mineral oil as the fill medium. The oil not only provides insulation but also has a cooling effect, helping to improve the thermal and electrical stability of the capacitor.

Durability:

Suitable for high-temperature and high-voltage environments, effectively suppressing discharge and breakdown.

Oil-immersed capacitors have strong oxidation resistance and self-healing capabilities. If minor local breakdown occurs, the self-healing effect of the oil can restore the capacitor's insulating performance.

Disadvantages: Performance is significantly affected by ambient temperature. Long-term use may lead to oil degradation. In environments requiring higher safety, regular oil quality checks may be necessary.

 

2. Solid Capacitors

Characteristics: Solid capacitors generally use solid materials such as polymers or ceramics as the fill medium. Compared to oil-immersed capacitors, solid capacitors eliminate concerns about liquid leakage and can provide higher mechanical strength.

Durability:

Suitable for high-vibration and harsh environments; their structure is more robust, with strong resistance to mechanical shock and vibration.

In terms of heat resistance, solid capacitors generally perform better than oil-immersed types and can adapt to a wider temperature range.

Disadvantages: Solid capacitors are typically larger in size and often more expensive than oil-immersed capacitors.

 

3. Dry-type Low-voltage Capacitors

Characteristics: Dry-type power capacitors usually use modified black gel as the internal filling instead of liquid or gas media. Dry insulating materials like modified black gel and resin have good insulating properties and flame retardancy, preventing the capacitor from catching fire under normal operating conditions.

Durability: Dry-type capacitors have stable electrical performance and are not affected by external factors such as temperature and humidity, ensuring circuit stability.

Disadvantages: Although dry-type capacitors have strong environmental adaptability, their lifespan may be slightly shorter than that of oil-immersed and solid capacitors under prolonged high-temperature, high-humidity, or high-pressure conditions.