Statistical analysis of Australian and New Zealand Power Transformer Catastrophic Fires

Modelling fires or explosions of power transformers is necessary to assist a utility determine the level of risk incurred from operating their network. However, a challenge is to collect enough data to establish a robust model when these events occur so rarely. Consequently, to collect such a large volume of usage data the Australian and New Zealand utilities were surveyed for information on their power transformers, and on those which had failed catastrophically (either fire or explosion). Approximately 88,000 service-years of operation were collected from 6,637 power transformers operated by 28 utilities between 2000 and 2016. Twenty-one fire or explosion events were identified over this period. Certain power transformer voltage groups appeared to be more likely to fail catastrophically as their age increased. The Poisson distribution was used to provide a method to determine in how many years a fire might be expected, as this can help plan asset replacement