Analysis of abnormal short circuit between turns of generator rotor windings

Abstract

In December 2018, during the normal operation of the NO.1 generator in a power plant, the online monitoring device of interturn-to-turn short circuit of the rotor #5 coil showed a suspected interturn-to-turn short circuit phenomenon. Check the rotor voltage, current, vibration and other data, are not found abnormal. The monitoring results of the on-line monitoring device for inter-turn short circuit in rotor of NO.1 generator show that there is some abnormal situation in NO.5 coil. After checking the test reports of RSO, ac impedance and power loss of generator rotor, no abnormal data was found. The correlation between the vibration of the rotor and the reactive power and the excitation current was checked. In addition, the rotor vibration of NO.1 generator does not increase during operation. It is suggested that the relationship between the vibration and the reactive power and the excitation current of the rotor rotor should be monitored, and the correlation analysis should be done.