Computation of breakdown voltage of long rod-plane air gaps in large temperature and humidity range under positive standard switching impulse voltage

The 50% breakdown voltage of the air gap is an important basis for the design of the external insulation of the high voltage power systems, and the atmospheric conditions have a large impact on the breakdown voltage of the air gap. The temperature and humidity of the operating environment of the high voltage power systems have a wide range. The breakdown voltages of the gaps obtained in the laboratory are mostly near the standard atmospheric conditions, and there is no good way to calculate the discharge voltage outside the standard atmospheric conditions. This paper established a 50% positive switching impulse breakdown voltage prediction model based on the cuckoo search algorithm optimized support vector regression for the rod-plane air gap. This calculation model is used to predict the selected prediction data. The predicted results are basically consistent with the experimental results, and the effect is better than the atmospheric correction results. Finally, the method was used to calculate the 50% positive impulse breakdown voltage of the rod-plane air gap under the extreme temperature and humidity conditions in Beijing. This method provides a new idea for obtaining the air gap breakdown voltage under different atmospheric conditions.