Analysis of Power Transformer Maintenance for Improved Reliability and Cost Efficiency: A Case Study in South Africa

Power transformer maintenance is critical to electricity utilities. Transformer failure results in electricity outages and replacement costs. In this study, both qualitative and quantitative research methods were used to determine maintenance factors which contribute to transformer failures. Semi-structured interviews and archival data collection methods were used. A total of 10 participants within the transformer maintenance field were interviewed and 30 previous transformer investigation failure reports were analysed in terms of their direct and root cause of failures. The aim of this research was to investigate the impact of inadequate transformer maintenance on transformer failures. It was found that skills, training and failure to follow maintenance procedures are some of the critical factors that contribute to inadequate transformer maintenance. Investment in the continuous training of maintenance personnel and the use of online monitoring diagnostic tools, will improve maintenance, which will reduce unplanned cost due to transformer failure.