On-line generator condition assessment using rotor-mounted sensor technology

Tennessee Valley Authority (TVA) utilizes rotor-mounted sensor technology installed on its Chickamauga 3 hydroelectric generator as a predictive maintenance tool and as a continuous operations monitor. The majority of the sensors are mounted between two poles on the salient pole generator rotor; these sensors scan the stator with each shaft rotation. Parameters continuously monitored include air gap at two axial locations, stator core temperature (using infrared sensors), partial discharge location (PDL), and magnetic flux density in both the direct and quadrature axis. This paper describes the process and results of an in-service inspection conducted on Chickamauga 3 hydrogenerator utilizing the scanner