Determination of Hot Spot Temperature using IEEE Thermal Model

Abstract

Failure of transformer in grid is one of the major concerns. In India the failure of distribution transformer is around 25% per annum, which is higher compared to developed nations. It is necessary to keep transformer in service for uninterrupted power supply. For uninterrupted operation of the Transformer it is necessary for effective Monitoring of the transformers health. The major factor that affects the transformers health is the thermal loading. The most important parameter in determining the transformer loading capability is winding Hot spot temperature. This paper presents two different Thermal models to determine the winding hot spot temperature. Simulation of the thermal models done in MATLAB. It compares the simulation results of both the thermal models. Both the thermal model uses Load current, different Temperatures, and Ambient temperature as an inputs and calculate the hot spot Temperature. The winding hot spot temperature can be used to find insulation ageing.