흡습된 수냉각 발전기 고정자 권선의 전기적 특성

Abstract

Insulation breakdown of water-cooled generator stator windings occurs frequently due to leakage of cooling water and absorption into the insulation material. Leakage and absorption problems of water-cooled stator windings are often found during regular preventive maintenance. To evaluate cooling water leakage and absorption, diagnostic tests were performed on two water-cooled turbine generators, which have been in service for 13 and 17 years, respectively. The test results of the measured electrical properties such as dissipation factor(<TEX>$tan{\delta}$</TEX>), capacitance and AC leakage current for water-cooled generator stator windings with wet bars are reported in this paper.