High-voltage switchgear is indispensable for power system. Condensation of the switchgear occurs frequently due to water vapor infiltration and water accumulation in cable trench, which may cause large-scale blackout of the power system. Effective dehumidification measures are crucial to safe and stable operation of the switchgear. In this paper, an air-conditioning based dry-air dehumidification measure is proposed for anti-condensation of the switchgear. Different airflow distributions are studied by numerical simulation of the thermal-humidity environment within the switchgear. Results show that the performance of the proposed dehumidification system is satisfactory. The switchgear wall temperature can be up to 7.6 °C higher than the return air dew point temperature, and the moisture content differences between the supply and return air can be more than 3.4 g/kg. Besides, some optimization measures for improving the dehumidification effect are proposed. After the optimization of the airflow distribution, the relative humidity and the temperature of the return air are reduced by 3.3% and 1.3 °C, respectively.

高压开关柜是电力系统必不可少的。由于电缆沟内水汽渗入和积水，开关柜经常结露，可能造成电力系统大面积停电。有效的除湿措施对于开关柜的安全稳定运行至关重要。在本文中，提出了一种基于空调的干空气除湿措施，以防止开关柜的结露。通过对开关柜内的热湿环境进行数值模拟，研究了不同的气流分布。结果表明，所提出的除湿系统的性能是令人满意的。开关柜壁温最高可比回风露点温度高7.6℃，送回风水分含量差异可达3.4g/kg以上。此外，还提出了一些提高除湿效果的优化措施。气流分布优化后，回风相对湿度和温度分别降低3.3%和1.3℃。