Experimental study of inter-laminar core fault detection techniques based on low flux core excitation

• Published in: IEEE transactions on energy conversion Vol. 21; no. 1; pp. 85 - 94
• Main Authors: Sang Bin Lee, Kliman, G.B., Shah, M.R., Dongwook Kim, Mall, W.T., Nair, N.K., Lusted, R.M.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.03.2006; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: AC machines; Electrical fault detection; Fault detection; Inspection; Insulation; inter-laminar insulation failure; Iron; Maintenance; Probes; regular maintenance; Signal to noise ratio; stator core fault; stator core inspection; Stator cores; Testing
• ISSN: 0885-8969; 1558-0059
• DOI: 10.1109/TEC.2005.853759

A comparison between two inter-laminar stator core insulation failure detection techniques for generators based on low flux core excitation is presented in this paper. The two techniques under consideration are: 1) the iron core probe based method developed recently and 2) the existing air core probe based method. A qualitative comparison of the two techniques is presented along with an experimental comparison on a 120-MW generator stator core. The test results are compared in terms of fault detection sensitivity, signal to noise ratio, and ease of interpretation, which are the main requirements for stator core inspection. In addition to the comparison, the performance of the iron core probe technique for machines with short wedge depression depth is presented along with the recent improvements in the algorithm. It is shown that the main requirements for stator core inspection are significantly enhanced with the new iron core probe-based core fault detector.