Fault Analysis of 600MW Generator Stator Bars in a Power Station

The stator bar, as the component connecting the coils in the generator to the external circuit, is the main carrier of current and electric field. It is hailed as the "heart" of the generator and plays a crucial role in it. Based on the specific fault phenomena of the stator bar of a 600MW large power station generator under complex operating conditions, this paper analyzes the fault causes in combination with the disassembly inspection. The direct cause of the fault is determined to be the grounding of the stator bar and the iron core. Furthermore, a three-dimensional numerical model of the stator bar is constructed based on the high-precision finite element analysis method, focusing on internal defects and their mechanism of partial discharge characteristics. It is pointed out that internal defects caused by different reasons will lead to increased partial discharge at the defects, and the main insulation will deteriorate due to the continuous influence of partial discharge during operation. The research and analysis results can provide a reference for the operation, maintenance, and fault diagnosis of the same type of stator bars to a certain extent, and have positive significance for promoting the continuous optimization, improvement, and professional management of the same type of equipment.