Predicting Transformer Temperature Rise in the Presence of Harmonics

Power transformers represent the largest portion of capital investment in transmission and distribution substations. One of the most important parameters governing a transformer¿s life expectancy is the hot spot temperature value. Temperature rise in a transformer depends on variety of parameters such as ambient temperature, output current and type of the core. The significance of harmonics in power systems has increased substantially due to the use of solid state controlled loads and other high frequency producing devices. An important consideration when evaluating the impact of harmonics is their effect on power system components and loads. Supplying non linear loads by transformer leads to higher losses, early fatigue of insulation, and reduction of the useful life of transformer.