Analysis of stator winding breakdown fault in a large pumped storage generator-motor
HUANG Hanyi1, ZHOU Xiaojun1, GUO Lianheng1, WANG Bogong2, FU Qiang3
1. Datang Xizang Energy Development Co., Ltd, Chengdu 610000; 2. Harbin Electric Machinery Company Limited, Harbin 150040; 3. Harbin Research Institute of Large Electric Machinery Company Limited, Harbin 150040
Abstract：This paper deeply analyzes the stator winding breakdown fault occurres in a large pumped storage generator-motor. First of all, the insulation material properties of the stator bars, the electrical properties of the stator bars before leaving the factory and the anti-corona properties are analyzed. Then, the properties of the removed stator bars are tested and analyzed, and the insulation layer is dissected and the bonding state is detected. Finally, the cause of stator winding damage is analyzed according to the on-site inspection. The analysis results show that the breakdown of the stator winding is caused by a bolt falling into the stator winding when the bolt of the stator ventilate plate is not locked tightly during installation. When the generator-motor operates, the bolt grinds the insulation layer of the stator winding, leading to the stator winding breakdown. This paper provides a technical basis for improving the installation quality of large generator-motor stator windings and avoiding the similar significant safety accidents.
2025, Vol. 26 
