Shaft current in AC induction machine. An online monitoring system and prediction rules

Author

Ong, Raymond ; Dymond, J.H. ; Findlay, Raymond D. ; Szabados, Barna

Author_Institution

GE Ind. Syst., Peterborough, Ont., Canada

Volume

37

Issue

4

fYear

2001

Firstpage

1189

Lastpage

1196

Abstract

This paper looks at a system for online shaft current monitoring. The proposed method of shaft current monitoring is noninvasive, reliable, portable, and low cost. Causes of the shaft current are described and prediction rules introduced. Fault conditions such as air-gap eccentricity, slot harmonics and broken rotor bars or end rings result in an asymmetrical flux pattern around the shaft, hence, resulting in shaft voltage. Bearing failures can occur when the voltage level exceeds the threshold of the oil film. The importance of the oil film is described

Keywords

asynchronous machines; electric current measurement; electrical faults; harmonics; machine testing; machine theory; machine windings; magnetic flux; monitoring; AC induction machine; air-gap eccentricity; asymmetrical flux pattern; bearing failures; broken end rings; broken rotor bars; fault conditions; oil film threshold; online shaft current monitoring system; shaft current prediction rules; shaft voltage; slot harmonics; Assembly systems; Bars; Condition monitoring; Costs; Industry Applications Society; Lubrication; Petroleum; Shafts; Testing; Voltage;

fLanguage

English

Journal_Title

Industry Applications, IEEE Transactions on

Publisher

ieee

ISSN

0093-9994

Type

jour

DOI

10.1109/28.936413

Filename

936413