Analysis and Handling of A Generator Stator Ground Fault

Stator ground fault protectionaction occurred during commissioning of a 600 MW generator in a certain power plant.According to the fault wave graphics and data,the paper analyzes generator voltage variation characteristic when the stator winding was grounded,and found that the main cause was the water pipe leakage at exciter end,which leads to the phase A stator grounded by high impedance through generator start-up test.The fault handling measures and the experience lessons were advised.