Voltage stress reduction for distribution line covered conductor
Putu Agus Aditya Pramana, Anindita Satria Surya, K. G. H. Mangunkusumo, Handrea Bernando Tambunan, Dhandis Rito Jintaka, Kemas M. Tofani, Muhammad Ridwan

PLN Research Institute

Abstract

Most of distribution line in Indonesia is surrounded by the vegetation, and it causing frequent interruptions of temporary ground phase when bare conductors are used to distribute power. To face this problem, the distribution utility replaced the bare conductor by using a covered conductor, which in the current standard, covered conductor has only one insulation layer, that is XLPE. During its operation, many covered conductors are found broken. The phenomenon is started by the occurrence of pinholes which is caused by cable degradation by voltage stress. When the lightning strikes, it cause over voltage and short-circuit current flowing from the phase to the ground through the pinhole. Under the mechanical tension, if the short-circuit current has sufficient energy, the covered conductor broken. To reduce the voltage stress and probability of pinhole occurrence, this paper proposed the novel design of covered conductors and it accessories. The study was conducted through simulations using finite element simulation tools. The simulation results show that voltage stress reduction can be done by adding semiconductor layer into the XLPE insulation, replacing the insulator material from ceramic to polymer, placing the bonding tip at the top, and modifying the binding method using the special clamp method.

Keywords: covered conductor, pinhole, stress reduction

Topic: Electrical Engineering