Effect of power system harmonic on degradation process of transformer insulation system

Harmonic is one of common phenomenon occurred during power system operation, especially when the non linear load applied within the power system. These harmonic will affect to the transformer, such as increasing hysteresis losses (magnetization) on steel and iron of transformer core, where the value is temperature depended. Degradation of transformer insulation can be driven by this temperature increasing. The harmonic that monitored continuously can be use as a reference parameter of degradation level of transformer insulation. To determine the actual condition of transformer insulation we developed Dissolved Gas Analysis (DGA) to enrich data analysis and using power quality monitoring to determine the power condition. This paper will discuss the possibility effect of harmonic phenomenon due to degradation process of transformer insulation system based on DGA and power quality analysis.