Monitoring of magnetic saturation level of a synchronous generator under load

This paper presents a new method to monitor magnetic saturation level of a synchronous generator operating in an electric power system. The proposed method makes use of air-gap permeance distributions, which can be derived from air-gap flux distributions measured by a search coil wound around a stator tooth of a generator. Tests were conducted on a laboratory-model power system to verify the validity of the proposed monitoring method. Test results under various operating conditions are presented to show a wide range of change in saturation level inside the generator. Its effects on generator performance in the power system and the benefits of the monitoring method are also discussed