Power transformer failure management on the Eskom distribution network in Limpopo

M.Ing. (Engineering Management)Abstract: Electricity is a crucial key component in the everyday life influencing the economy, safety, health, productivity and comfort of the people. Power utilities continue to make the continuity of electricity supply to the consumers their first priority. Power transformers are the crucial part of the power system network because they regulate the voltage either up or down on the electrical network for safe use by the consumers. Their reliable operation on the network is very critical because it directly impacts the reliability and stability of the entire electrical network connected to it. One of the major challenges power utilities face is the failure of substation power transformers on the distribution network. Sudden failures of these transformers cause the interruption of supply to the customers. For the utility, it causes high transformer repair costs and revenue loss. The power utility is also forced to replace the failed power transformers in order to reduce the outage time for the affected customers. Although power transformers have become the heart of the distribution network, the success rate for these transformers to complete their full life cycle is not a guarantee. The performance of the power transformers on the Limpopo distribution network has not reached the projected target set by the plant performance department in the past four years and this is cause for great concern. There was a number of power transformer failures recorded in the substations. After investigations were conducted, it was found that the major causes for these failures were aging, overloading, improper maintenance schedule, internal faults and insufficient security measures in substations in remote areas. This dissertation looks at the methodologies that are currently being implemented to ensure that the installed substation power transformers approach or complete their full life cycle. It further proposes the improvement of the methodologies currently being implemented. The conclusion reached in this study is that in order for the substation power transformer failures on the Eskom distribution network in Limpopo to decrease, the methods that can alleviate the problem include: installation of an online monitoring system on the power transformers; improvement of the maintenance schedule; installation of a backup transformers in single transformer substations; improvement of the security measures in substations that are located in remote areas; putting asset replacement plans in place for transformers that are approaching their..