Computations of Magnetic Field Anomalies in Synchronous Generator Due to Rotor Excitation Coil Faults

The paper presents an approach to model shorted turns in rotor excitation winding of synchronous generator using finite element analysis. It enables detailed examination of magnetic field at several operating conditions under healthy and faulty states which are difficult or even impossible to carry out by available measurement methods in industrial environment. It is confirmed that an extensive analysis should be performed to assure accurate healthy/faulty state predictions, since the level of diagnostic signal is considerably influenced by a combination of many machine design and operating parameters.