DocumentCode :
949825
Title :
Method of detecting and modelling presence of shorted turns in DC field winding of cylindrical rotor synchronous machines using two airgap search coils
Author :
Stoll, R.L. ; Hennache, A.
Author_Institution :
University of Southampton, Department of Electrical Engineering, Southampton, UK
Volume :
135
Issue :
6
fYear :
1988
fDate :
11/1/1988 12:00:00 AM
Firstpage :
281
Lastpage :
294
Abstract :
A method is described for detecting the loss of one or more turns in a concentric coil of the rotor field winding of a synchronous machine using two search coils in the airgap. This back-to-back method yields an EMF proportional to the rate of change of the `missing¿ flux linking the search coils, and is sufficiently sensitive for the coils to be positioned close to the stator surface. A two-dimensional linear analysis of the airgap field is used to model the method with good accuracy, and includes an estimate of the resulting unbalanced magnetic pull. A simple one-dimensional analysis predicts the EMF harmonics that are introduced by static or dynamic rotor eccentricity. Results from a small four-pole experimental machine are presented, including the effect of a known amount of static eccentricity. Calculations for a larger two-pole machine are also included, and a possibly useful method of fault location detection using the ratio of the magnitudes of only two harmonics taken from the search coil output is discussed.
Keywords :
fault location; harmonics; machine testing; rotors; synchronous machines; turbogenerators; DC field winding; EMF; airgap field; airgap search coils; back-to-back method; concentric coil; cylindrical rotor; dynamic rotor eccentricity; fault location detection; four pole machine; harmonics; modelling; one-dimensional analysis; shorted turns; static eccentricity; synchronous machine; turbogenerator; two-dimensional linear analysis; two-pole machine; unbalanced magnetic pull;
fLanguage :
English
Journal_Title :
Electric Power Applications, IEE Proceedings B
Publisher :
iet
ISSN :
0143-7038
Type :
jour
DOI :
10.1049/ip-b:19880031
Filename :
4648699
Link To Document :
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