Effect of inductance in series with polluted high voltage insulators on lightning impulse withstand

Flashover due to pollution in high voltage insulators can cause power interruptions through short circuits. This situation has a negative impact on the continuity of the system's supply and economic losses. Pollution flashover in high voltage insulators is a subject that researchers have been working on for many years, but it still continues to be a critical and special issue from technical and economic perspectives. In this thesis, it is aimed to examine the flashover behavior of insulators through theoretical, experimental and simulation studies. For experimental studies, lightning impulse voltage generator and water column test system were established and flashover tests were carried out under impulse voltages. With the help of the water column mechanism, the conductivity value can be easily changed to represent the pollution on the insulator. Experiments were carried out with different conductivity values and column lengths and the results were analyzed. In addition, the method of adding series inductance to the insulator, which is a new approach in the studies of pollution flashover in insulators, was applied on the water column test set and its effect on the pulse flashover performance was investigated. In the experiments, different dirt conductivity and inductance values were used. The experiments were carried out under positive impulse voltage. During the experiments, the pulse voltages and currents that do not cause or cause flashover in different water column lengths were recorded and their graphs were drawn. The data obtained at different inductance values were compared with each other and with the case without inductance. As a result of the experiments, the effect of inductance on reducing the flashover, that is, increasing the flashover voltage has been shown. The increase in column length had an effect on increasing the initial flashover voltage. Pulse characteristic curves are extracted for a given conductivity, column length and inductance values. Mathematical expressions were derived for the obtained characteristics and it was possible to estimate the flashover times occurring at impulse voltages with different peak values.