Effects of broken glass insulator on charge distribution along insulator strings

Ability of overhead insulators to insulate the power lines and carrying the weight of the line conductor are considered to be of basic importance to the transmission system. However, these insulators can be broken for various reasons during their service life. Although research studies shows that the existence of broken glass insulator or stub as part of complete string may alter the local voltage distribution, the knowledge on the stub insulator is still insufficient. The insufficiency is particularly on the charge distribution on the stub insulator. Therefore, this paper investigates the charge distribution pattern on the stub insulator in a string insulator. The results reveal that the distribution of charge is positively distributed for the stub insulator located at any locations in a string except near to high voltage electrode; while perfect insulator still possess negative charge distribution. This outcomes can be used to detect the presence of stub in the string so that immediate action can be taken.