Grounding fault location of large turbo generator based on stator winding distribution

Abstract

Stator grounding is the most common fault of a large generator. If the accurate coil of the fault can be located quickly and effectively, the maintenance progress of the generator can be greatly sped up, and the fault generator can be put back into use as soon as possible. For this purpose, a stator grounding fault location method for a large steam generator is proposed, which takes the distribution of winding potential into account. Firstly, the fault characteristics and the influence of winding potential distribution are analyzed when a single-phase ground fault occurs in a large generator, and the amplitude equation and phase equation of zero sequence voltage are constructed. On this basis, the potential distribution of stator winding can be analytically expressed, so the fault location can be directly calculated by the numerical solution method. Simulation analysis verifies the effectiveness of the proposed method.