Existing models to predict surge voltage distribution withinstator windings have been modified to take into account the effect ofall three phases of the winding simultaneously. Furthermore, a methodhas been proposed which is capable of predicting voltage distributionwithin the winding, when the machine is faced with a train of repetitivesurges from the supply end. The advantage of the proposed method is thatit does not require considerable computing power as compared to the casewhere the winding is subjected to a single surge and thereby enablingon-line calculations required for condition monitoring of the machineunder load conditions. It has become evident that reducing therepetition rate further from a critical value has a strong influence onthe resulting interturn voltage distribution within the winding. Thiscould be used by both machine and switchgear manufacturers to ensurebetter coordination between breaker switching characteristics andmachine winding insulation strength, and thereby reduce considerably theprobability of insulation failures
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