What are the effects of air pressure changes on different types of electrical components?

The impact of air pressure changes on different types of electrical components is mainly reflected in the following aspects:

The internal vacuum environment of VTZ-12 vacuum circuit breaker is not affected by altitude-related air pressure changes, but attention must be paid to sealing to prevent leakage. High-altitude environments may actually reduce the sealing requirements due to the reduced internal and external pressure difference.

SF6 circuit breakers rely on SF6 gas for insulation, and their casing must withstand external air pressure changes to maintain internal gas pressure. As altitude increases, the internal and external pressure difference increases, potentially increasing the strength requirements for the casing.

Clearance and Insulation Strength: In low-pressure environments, the dielectric strength of air decreases, leading to a drop in breakdown voltage. In high-altitude areas, phase spacing and clearance need to be adjusted according to the altitude coefficient to ensure insulation safety.

Insulation Medium Stability: The insulating oil in oil-immersed transformers has stable properties and is unaffected by changes in external air pressure. However, the tank's sealing must be ensured to prevent leakage due to pressure differences.

Heat Dissipation and Temperature Rise: Decreased air pressure may affect heat dissipation efficiency (e.g., convection), leading to increased temperature rise with altitude. Temperature rise control is necessary.

Decreased Heat Dissipation Performance: In low-pressure environments, air density decreases, weakening the effect of forced convection cooling and leading to a significant increase in equipment temperature rise (e.g., the temperature rise of motors and transformers is approximately linearly correlated with altitude).

Sealing and Material Aging: Lower atmospheric pressure accelerates the aging of sealing materials, potentially causing gas or liquid leaks; simultaneously, ultraviolet radiation and temperature fluctuations accelerate the aging of insulation materials.

Theoretical Relationship: According to gas breakdown theory, as gas pressure decreases, the mean free path of charged particles increases, and the breakdown voltage decreases. In practical applications, the characteristic index n needs to be determined experimentally to correct for the external insulation discharge voltage.

 

 

Summary

The impact of gas pressure changes on electrical components varies depending on the component type and operating environment, and must be comprehensively considered in conjunction with factors such as sealing performance, insulation performance, and heat dissipation.