An Experimental Study on Water Absorbtion Characteristics of Generator Stator Bar Insulation by Cooling Water Temperature in 500MW Capacity Power Plant

The mechanical integrity of generator stator windings is one of the critical point because the electric power is generated and conducted to power system through these windings. De-mineralized water is used to cool stator bars during the normal operation of generator in large power plants because the water cooled method has highest cooling efficient. Water absorption of bar insulation is progressed by several causes such as generation of water leak path by corrosion, delamination of insulation by vibration, and inadequate water treatment, etc.. Reliable water absorption diagnostics of generator stator bar is important to ensure the availability of power plant and to reduce maintenance cost by generator accident. It is described that the water absorption characteristics for generator stator bar insulation used in 500MW capacity standard fossil power plant by cooling water temperature. It is verified that the management of stator cooling water temperature is one of the important factors to decrease water absorption rate of generator stator bars.

500MW급 화력 발전기 냉각수 온도에 따른 고정자 권선 절연재의 흡습 특성에 관한 실험적 연구