Exploring the effect of an asset management system on the efficiency and reliability of transformers in a power utility

Abstract

The research presents an analysis of Eskom’s transmission transformer performance in support of the company’s Asset Management System. Eskom Transmission is currently implementing an Asset Management approach to making investment decisions. Literature review revealed that the grid adopted PAS 55, currently considered the best practice in Asset Management in the industry, in 2010. The results from this analysis can be used to decide on appropriate asset strategies on whether to extend the life span of an asset or to replace it. This will ensure that most effective investment decisions are made in order to improve the reliability and lifespan of company’s networks. Eskom is experiencing the pressures of operating and maintaining older transmission substations with reductions in their work force and operating budgets. The Grids have established a maintenance plan to perform scheduled maintenance to assess the condition of equipment which mainly follows the time based management in order to maintain reliable and cost-effective operation of plant. Time based maintenance and condition based maintenance are the main strategies used in Eskom Transmission. There is an increase in transformer maintenance defects due to network constraints, in sufficient maintenance teams, reduced skills, insufficient network contingencies etc. Substations need to be inspected on a regular basis by experienced substation personnel to effectively maintain continuous operation. The data used in this study was collected by means of interviews and questionnaires of a sample group within the North Grid. More percentages of people in the Grid were not interviewed instead were issued with questionnaires. This was done in order to ensure that the sample group is a fair representation of the Grid. The results of this research confirm that there is in fact a real requirement to train the artisans and supervisors in terms of asset management principles to increase equipment reliability and performance.