Detection of faults in rotor-windings of turbogenerators using sweep frequency response analysis (SFRA) method

Summary

A new approach for fault detections within rotor windings is the “Sweep Frequency Response Analysis” (SFRA) method that is also widely used in diagnosis of power transformers. This paper gives an overview about the possible use of this measurement method and explains the principal functionality in detail. Comprehensive measurement results from standstill as well as during rotation in a spin pit are shown and discussed. Advantages and disadvantages of the measurement technique are summarized and compared to other well-established diagnostic methods. To determine the effectiveness of the SFRA for rotors of turbo-generators multiple measurements with artificial faults are carried out. It has been shown by measurement in standstill and in a spin-pit that permanent and speed-dependent winding shorts change the signal response. Especially the value of the first resonance frequency shows promising evaluation results for assessment of inter-turn, coil-to-coil or winding-to-ground shorts.

Additional informations

Authors

KASHIWAGI, CISSE, HADJADJ, AMBROISE

Keywords

Rotor diagnosis, Inter-turn short, SFRA, RSO