Optimisation of recloser placement methods on medium voltage distribution networks

Abstract

Re-evaluating methods in any business is essential, as it reinforces knowledge and improves methodologies. Improving the reliability of electrical distribution networks is key for a utility like Eskom. Having fewer customers without electricity during an outage and more income for the utility is the focus of this study. Eskom’s standard for placing reclosers (automatic breakers) focuses on reaching their performance targets and not on the financial costs and benefits thereof. The purpose of this study is to present a method to optimise the placement of reclosers on the distribution networks. Eskom could, by focusing on the financial benefits of recloser placement, improve their performance targets as well as save more money on fault conditions. A method using cost-benefit analysis (CBA) is used and explained to analyse the placement of reclosers on an electrical distribution network. Mathematical calculations and a matrix table are used to determine the maximum number and sequence of placement of the reclosers to be installed on the networks. The findings of this study show that placing reclosers on the network using this method will pay for itself in a short period. The results show the financial benefits as well as performance improvements. By using the proposed method, the exact placements for reclosers may be indicated and less guesswork will be required from the engineers. The study was done using data from actual distribution networks. Possible future studies can be done by combining recloser placements with other protection-sensing equipment such as Fault Path Indicators or Current Voltage Monitors.