Cost effective reliability improvements in 332kV/11kV electricity distribution networks - a case study in western province south 1, Ceylon Electricity Board, Sri Lanka.

Abstract

Electricity Distribution system in Sri Lanka consists of 33kV, 11kV and Low Voltage (400V/230V) networks. Providing reliable supply to the end user is a challenging task to any utility. Therefore, utility is trying to develop their network to provide a highly reliable supply to user by investing in system developments. In this research, a method is introduced for selecting a cost-effective solution to improve the reliability of the 33kV and 11kV distribution systems among different proposals. Improvement of conductor, its insulation and protection of short duration faults are focused to develop in this research. Part of the method developed in this research, includes the software tool (DisFeeRIA) to analyze the reliability indices and cost for the relevant proposal. Data Base of the DisFeeRIA software tool includes failure rate improvement, mean time to repair, costing of each option considered etc. The analysis is done using user input of the particular feeder, data base of the software which are the part of outcome of the research. Medium Voltage Underground cable (MVUGC), Medium Voltage Aerial Bundle Conductor (MVABC), Medium Voltage Covered Conductor (MVCC), Room Temperature Vulcanizing (RTV) Si-R coating on existing bare line ceramic insulators are considered as options for improving conductor and it’s insulation. One of the latest & innovative technologies used in distribution network, Pulse closing technology is used to reduce momentary interruptions and enhance the life time of the equipment which used in distribution network. Developed software and method were tested by case study done for Distribution network in Western Province South – 01 of Ceylon Electricity Board (CEB). Three (03) feeders were selected in different areas from Urban, Coastal & Rural. The method that is introduced in this research is very important to utilities for planning of Electricity Distribution network.