Diagnosis of inter‐turn short circuit in excitation winding of pumped storage unit based on frequency‐resolved circulation spectrum

The online monitoring of inter-turn short-circuit (ITSC) faults in excitation windings pumped storage units is easily affected by static air-gap eccentricity (SAGE) and armature response, the early fault characteristics cannot be identified effectively. To address these problems, this study proposes a frequency-resolved circulation spectrum (FRCS) diagnosis method for ITSC windings. Firstly, equation same phase multi-branch under SAGE compound conditions derived based on structural electromagnetic induction relations, obtains characteristic harmonics loop current caused faults. Secondly, introduces implementation FRCS, considering unit with generation capacity 334 MVA as research object. This develops two-dimensional finite element simulation model, calculates magnitude in-phase branch at different levels, extracts corresponding time frequency domain verifies effectiveness proposed comparative experiments. Finally, MJF-30-6 Synchronous Generator Experimental Platform Power System Dynamic Simulation Laboratory, operation levels simulated, data are collected FRCS analysis. experimental results demonstrate that can effectively eliminate reaction interference, identify weak visualise severity form pixel dots.