Impact of work environment

Here mainly refers to the temperature, humidity, rain, dust, small animals and other external factors. There are three kinds of installation forms of reactive power compensation device, namely the compensation cabinet in the distribution room, the compensation equipment of box type transformer, and the column compensation box of line common distribution transformer. Among them, the first two can be regarded as indoor installation, while the column compensation box of public distribution transformer belongs to outdoor installation, and its working environment is the worst.

The outdoor installation of the device box is directly in contact with the external air environment, the heat insulation effect is poor, the temperature inside the box changes violently, the condensation phenomenon is easy to appear, and it is easy to be interfered by the external temperature, humidity, rain, dust and small animals. All these factors affect the reliability and life of the device.

a. Temperature. In recent years, in the product technical parameters provided by the manufacturer, the expression of environmental temperature is different, including 40 ℃, 55 ℃, 60 ℃, 65 ℃, etc. The author has done the temperature test experiment in the hottest summer: when the temperature is 37 ℃ on a sunny day, the temperature of the metal shell of the compensation box can reach 59 ℃, the temperature of the air in the box can reach 45 ℃, and the temperature of the fixings in the box can reach 48 ℃. Obviously, the device with ambient temperature of 40 ℃ can not meet the requirements, and the device with ambient temperature of 55 ℃ has insufficient margin. As the most sensitive components affected by temperature are electronic circuit components, and the working temperature of industrial electronic devices is generally 25-75 ℃, the device temperature parameters of 60 ℃ and above are more suitable under the principle of fully considering the ambient temperature and leaving a certain margin.

b. Humidity. In the product technical parameters provided by the manufacturer in recent years, the expression of relative humidity is also different, some are expressed as "the relative humidity does not exceed 50% when the temperature is 20 ℃, the relative humidity does not exceed 90% when the temperature is 40 ℃", some are expressed as "the relative humidity does not exceed 90% when the temperature is 40 ℃, and some are expressed as" the relative humidity does not exceed 80% ". According to the situation that the column compensation device is used as outdoor equipment, the above requirements of relative humidity are low, especially in southern Jiangsu, the humidity is very high in summer Meiyu season, so the parameter of relative humidity should be 95%.

c. Rainproof, dustproof and condensation proof. The performance of rainproof, dustproof and anti condensation is related to the structure and sealing of the box. In principle, there is a contradiction between the measures to prevent rain and dust and the measures to prevent condensation. Under relative conditions, the better the sealing measures are, the better the rain proof and dust-proof effect will be, and the worse the anti condensation effect will be. This is because: in the case of non absolute sealing, due to the poor breathing of the box, when the temperature and humidity changes greatly, the humid air inside the box can not be convective, and it is easy to condense inside the box. Therefore, there should be higher technical requirements in the production of the device box. It is necessary to properly grasp the relationship between rainproof, dustproof and anti condensation, and reasonably improve the protection level standard of the box, so that these two problems can be properly solved.