Air-insulated switchgear is a crucial component of power transmission and distribution networks. To observe the insulation status of switchgear by detecting the components of air decomposition during partial discharge, the decomposition components of air under partial discharge conditions were analyzed through switchgear simulation experiments and theoretical calculations.
The air decomposition components detected during the experiment were CO and NO2 gases. When the relative humidity was 70% RH%, and the discharge voltage increased from 6kV to 7.5kV in a 0.5kV gradient, the concentrations of both CO and NO2 increased with increasing voltage. When the discharge voltage was 6.5kV, and the air humidity was 50% RH, 7% RH, and 9% RH, the CO concentration increased with increasing humidity, while the NO2 concentration decreased significantly with increasing humidity. Under different voltages and humidity levels, CO showed a linear increasing trend; however, due to the reaction with water molecules in the air, the NO2 concentration showed a gradually decreasing growth rate and a saturation trend over time.
Switchgear equipment plays a crucial role in power transmission and distribution. It ensures the stable operation of the power system and disconnects interconnected equipment in the event of a system fault, effectively protecting the safety of power operators and electrical equipment.
However, insulation defects are unavoidable during the manufacturing and operation of switchgear. These defects can trigger partial discharge, sparks, flashover, and other discharge phenomena within the equipment during continuous operation, leading to further insulation degradation and operational failures, ultimately causing system power outages and paralysis.
Among the various discharge phenomena in switchgear, partial discharge is difficult to detect during its discharge process, easily developing gradually and ultimately leading to serious consequences. Therefore, finding an effective method to detect partial discharge within switchgear is crucial. Since partial discharge is accompanied by physical phenomena such as light emission, heat generation, sound waves, and strong electromagnetic fields, these physical characteristics can be used for partial discharge detection.
Hertzman Power's 10kV compact atmospheric pressure sealed air-insulated switchgear adopts an innovatively designed atmospheric pressure GIS air-insulated sealed enclosure, using a fixed circuit breaker structure instead of a withdrawable trolley structure. The vacuum interrupter assembly, three-position isolating/grounding switch, horizontal busbar, and incoming busbar, among other main conductors, are housed within a sealed enclosure. A patented technology utilizes a slight positive pressure release to achieve a stable atmospheric pressure state during energized operation. This effectively isolates dust, contaminants, and humid air from the operating environment. Operation and maintenance do not affect the sealing and insulation levels, fundamentally preventing flashover faults caused by contamination and moisture in the main conductors within the sealed enclosure. This technology has been applied in island defense projects. Atmospheric pressure air insulation possesses self-healing capabilities within GIS structures, achieving the same environmental adaptability as gas-filled products, while fundamentally eliminating the risk of insulation degradation caused by air leakage from pressurized enclosures.
The enclosure features an IP65-rated sealed design. The modified metal enclosure, combined with imported specialized sheet metal sealant, forms a clean atmospheric pressure air sealed enclosure with an air filter. This effectively isolates dust, contaminants, and moisture, eliminating the risk of surface creepage flashover damage caused by contaminants covering the insulation material in humid environments. This ensures that the product's insulation strength does not decrease throughout its lifespan. The air chamber features a balanced atmospheric pressure design, a C-GIS design that eliminates the need for pressure detection, and an air filter that protects the pressure balance. This effectively isolates salt molecules and small particles, ensuring clean air and reducing discharge phenomena.