The diffusion characteristics and mechanism of O3 caused by corona discharge under the coupling of temperature and humidity conditions

High-voltage switchgear is an indispensable core equipment in power distribution networks. Its interior is susceptible to corona discharge, which inevitably leads to substantial energy loss and degradation of equipment insulation performance. In this paper, experimental verification and simulation modeling methods were employed to investigate the generation, diffusion patterns of O 3 caused by corona discharge within the high-voltage box under various temperature and humidity conditions, as well as the correlation characteristics between O 3 production and the degree of discharge. By establishing an O 3 diffusion simulation model, the evolution characteristics of O 3 over time and space under the influence of different temperature and humidity were calculated and analyzed, and the influence mechanism of multiple factors on O 3 diffusion was revealed. The results show that for the actual process of O 3 generation, the concentration of O 3 shows a saturation trend in the later stage of discharge. An increase of 20 °C in ambient temperature leads to an approximate 60% rise in O 3 content, while a 20% rise in relative humidity results in an around 80% reduction in O 3 content. With the increase of applied voltage, the concentration of O 3 generated by discharge rises significantly. Under the same temperature and humidity conditions, the O 3 concentration at an applied voltage of 15 kV is approximately three times that at 10 kV. During the process of ozone diffusion and decomposition. The concentration of O 3 declines significantly as temperature rises and shows a decreasing trend with increasing humidity. The O 3 concentration at 40 °C is 50% lower than that at 20 °C, and the concentration at 80%RH is about 20% lower than that at 40%RH. The research can provide theoretical and experimental references for the monitoring of corona discharge O 3 and the status assessment of high-voltage switchgear cabinet type box-type equipment.