Performance Analysis of Synchronous Generators under Stator Windings Ground Faults near the Star Point - Experimental Verification

In this article, a comprehensive mathematical model for synchronous generators under stator winding faults near the star point is described. The model is developed using the Modified Winding Function. The model includes space harmonics and their effects on windings inductances. The model is verified using electromagnetic analysis through 2D Finite Element Analysis simulation and experimental testing. The results prove the accuracy of the proposed mathematical model in reflecting the features of synchronous generators under stator windings ground faults in different parts of the winding and specifically near the star point. The developed modeling technique can be used for designing protections schemes for the very challenging 100% stator winding ground fault protection. The model enables protection designers to obtain rich set of data for protection relays designing and testing.