Operational Limits of a Large Hydro Generator with Bypassed Coils and Circuits

This paper presents the analysis of the performances of an existing hydro generator of 22.5 MVA, 6.6 kV, 60 Hz, 60 poles, 396 stator slots, with 6 parallels circuits per phase. The generator is operating with 5 bypassed stator coils and 2 removed circuits. The first objective of this paper is to determine the capability of this studied generator to operate safely with rated MVA or reduced load. Analytical computations based on LABC model are carried out and the obtained results are compared to the site measured parameters.