Circulating current analysis in the parallel-connected windings of synchronous generators under abnormal operating conditions

In large synchronous generators, the windings are usually parallel-connected in order to deliver the normal characteristics at the terminals of the machines. Under normal conditions, there is no circulating current between the windings of one phase. But when a failure occurs like an eccentricity or some other faults, the symmetry between parallel windings is broken and a circulating current will occur. The aim of this paper is to compute the current that circulates under faulty conditions like eccentricity and short-circuits in the rotor winding. A comparison with measurements made in a laboratory machine is also presented