Detection of inter-coil short circuits in synchronous machine armature winding on the basis of analysis of machine magnetic field

This paper deals with detection of inter-coil short circuits in the synchronous machine armature winding, for the machines having the armature winding with coils, based on the analysis of the magnetic field present in the machine. Applying FEM (finite element method) [4] to the generator model, magnetic field wave forms in the machine have been calculated for every point of interest, under correct and faulty conditions. Selection of the stated points has been planned with the intention to reach a correspondence of the points of interest for flux density among the calculated points and points accessible for measuring with Hall sensors in the actual machine. Comparison of results shows changes in magnetic fields in the machine caused by analyzed faults. The results of calculations are confirmed by measurements on a real machine that is altered in a way that it is possible to simulate inter-coil short circuits of one or more coil turns of the armature winding. The aim of this study is creation of a contribution to the knowledge portfolio pertaining to detection of rotation machines failures and faults, or, in other words development and improvement of monitoring systems in charge of surveillance of rotation machine condition.