Abstract: In high humidity environment, the switchgear is easy to get damp and form condensation, resulting in a sharp decline in the insulation performance of the electrical equipment in the switchgear. In order to improve the ability of switchgear to cope with humid environment, this paper takes 12 kV high-voltage switchgear as an example to propose a comprehensive evaluation method of heater layout which considers temperature rise level, temperature rise uniformity and dehumidification capacity. Firstly, based on the comprehensive evaluation method of heater layout, the optimal heater layout test is carried out to select the optimal heater layout scheme. Then, the decondensation test is carried out on the basis of the optimal configuration test of the heater to verify the dehumidification performance of the heater layout scheme in the high humidity environment. Finally, combined with the numerical simulation of temperature-fluid multi-physical field, the distribution of temperature and flow field under the condition of heater installation is studied. The results show that the three 50W heater schemes are the best among the two selection strategies. The optimal heater arrangement scheme can completely remove condensation within 4.5h without causing excessive heating of insulation parts.

Key words: high voltage switchgear, moisture condensation, heater arrangemen, multi-physical field simulation