Pattern Recognition of Inter-Turn Short Circuit Fault in Wound Field Synchronous Generator via Stray Flux Monitoring

Abstract

This paper provides a novel approach to discriminate the Inter-Turn Short Circuit fault (ITSC) in salient pole synchronous generator based on the use of non-invasive sensors. A stray magnetic field is used as a non-invasive signal that could provide valuable data regarding the condition of the synchronous machine. The captured signal under different severity of the ITSC fault is examined by using a classical signal processing tool based on Fast Fourier Transform. A unique feature based on extracted sub harmonics from the stray magnetic field is used to demonstrate the sensitivity of the signal to fault severity increment. It has been shown that the nominated feature do not have any sensitivity to the load variation. The theoretical hypothesis which is supported by using finite element method analysis is tested and verified by experimental results.