Measured Winding Impedances of a Large A-C Motor

This paper presents measured R, L, C, G parameters of the stator winding of a large A-C motor. The values of these parameters were determined within the frequency range from 100 Hz up to 10 MHz with a high quality impedance analyzer. Twenty different measurements of the R, L, C, G parameters of turns, coils and phases are reported. The results should be of help to utility engineers concerned with turn insulation breakdown and surge protection of large A-C motors. The presented data can be used as an aid in development and calibration of wave propagation models needed for computation of electromagnetic transients in the windings of rotating machines. Ontario Hydro's assistance in this work and EPRI's funding are gratefully acknowledged.