Characteristic Impedance of Stator Bars to Study Partial Discharge Pulse Propagation in Generators

Partial discharge (PD) test is one of the most commonly used methods for monitoring the status of generator insulation system. Despite the major use of this method, the interpretation of its results faces many challenges. Therefore, it is necessary to study and recognize the PD pulse propagation process in the stator winding. In this study, the characteristic impedance of a generator bar is calculated to increase the accuracy of modeling the stator winding. Depending on how the bar positioned in the stator core, the characteristic impedances of the slot part and the end winding are obtained using finite element method. Finally, based on the results obtained, a suitable model for PD pulse propagation is implemented in EMTP software to compare the simulation results with the previous experimental studies.