Condition monitoring of brushless three-phase synchronous generators with stator winding or rotor circuit deterioration

This paper presents experimental and theoretical analyses used to establish electrical features that can be utilized as indicators of armature winding, field winding or rectifier diode deterioration in brushless three-phase synchronous generators before the imperfection progresses to become a ground fault. The paper begins with the description of a 5 kVA synchronous generator specifically designed and constructed to allow for simulation of armature winding, field winding or rectifier diode deterioration in a brushless machine. Subsequently, a description of the experimental methodology and the results of experiments are presented. Specific features that can be used as indicators of the deterioration are described and a theoretical basis for them is provided. The proposed features can be obtained continuously during normal generator operation. As such, they can be used as a basis for both winding brushless and brush-fed synchronous generator health monitoring applications.