The impact of turn-to-turn short circuits of synchronous generator rotor winding based on wavelet analysis of leakage flux

Abstract

The relevance of the work is conditioned by the lack of proven methods of functional diagnostics of turn-to-turn short circuits in synchronous generator windings, but an occurrence of this damage in high power generators causes large economic losses. The main aim of the study is to determine the diagnostic criterion of turn-to-turn short circuit occurrence based on the wavelet analysis of EMF at a magnetic field sensor output in the area of the generator end plate. The methods used in the study: The analysis of the experimental data meant for obtaining the scale-time spectrum which allows detecting local nonuniformities of an analyzed signal is carried out on the basis of the continuous wavelet transform. The results: The algorithm is finally presented as a computer code. The algorithm is tested for three input signals from the magnetic scattering sensor installed in the generator end plate area. The authors determined the criterion of the turn-to-turn short circuit occurrence by variation value of the continuous wavelet transform spectrogram of the magnetic flux scattering sensor signal. The paper introduces the results of experimental data analysis on the basis of the proposed algorithm which indicates the event of a turn-to-turn short circuit.

Keywords

• synchronous generator rotor
• magnetic leakage flux
• coiled rotor circuit
• integral wavelet spectrum
• wavelet coefficients variance