Research of AC and DC Discharge Characteristics of Rod-Rod Air Gap Under Low Temperature

As temperature decreases, the movement of molecules in air slows down, which is not conducive to the generation of impact ionization, so that the insulation strength of the air gap increases. However, in practical engineering, the influence of temperature is often overlooked, especially concerning discharge characteristics of air gaps under low-temperature conditions, which remains scarcely investigated. In this study, rod-rod air gaps discharge experiments were conducted to investigate the AC and DC discharge characteristics under temperature conditions ranging from −42 ℃ to 30 ℃. Experimental data and discharge characteristic curves were obtained, and the influence of temperature on the AC and DC discharge voltages in the rod-rod air gaps was analyzed. The results indicate that with the increase in temperature, both AC and DC discharge voltages in the rod-rod gaps gradually decrease. Additionally, the impact of temperature on the discharge voltages becomes more pronounced with larger gap distances. The research results have certain guiding significance for the design and optimization of the external insulation structure of power transmission and transformation equipment under low temperature conditions. Furthermore, this study provides important reference value for ensuring the safe operation of power grids, enhancing the stability of electrical equipment, and reducing operation and maintenance costs.