Analysis of Flashover Voltage of Porcelain and Glass Insulators under Different Temperatures with Various Levels of Pollution and Humidity

Insulators of overhead transmission lines are continuously exposed to various environmental conditions. Factors such as pollution, humidity, temperature, and electrical stress negatively affect their performance. Environmental stresses can reduce surface resistance, increase leakage current, and ultimately lead to the flashover voltage of insulators. As a result, overhead transmission lines and some electrical equipment become disconnected from the power network. This can cause interruptions in energy transmission and reduce electrical grid reliability. In this paper, the flashover voltage of porcelain and glass insulators with artificial/natural pollution, as well as under clean conditions (non-pollution) and different levels of humidity and temperature, is measured, and the results are evaluated and analyzed. The experimental findings show that there is a mathematical correlation between the flashover voltage of the polluted insulators and the various levels of humidity and temperature. The coefficients of the model are determined in such a way that the results of the presented model are in good agreement. Besides, the experimental results indicate that the increase in temperature has a significant effect on the behavior of the insulators examined under different pollution and humidity conditions. The results show that the flashover voltage of the insulators decreases between ۴% and ۴۱% under constant pollution and humidity with different temperatures. It was also revealed that it is possible to estimate the flashover voltage of the insulators under different humidities using the correction factor of the flashover voltage.

Keywords:

Porcelain and glass insulators , flashover voltage , Pollution , Humidity , temperature