Introduction to Different Types of Faults in Synchronous Generators

Condition monitoring in electrical machines, particularly in synchronous generators, has increased considerably in recent years. This chapter investigates the different fault types encountered in synchronous generators and the reasons for the creation of these faults. The health of a synchronous generator, and the origins of the faults depend on the materials used, the types of mechanical and electrical stresses, and the machine's operating conditions. Different stresses that act as major factors in the stator winding destruction are categorized as follows: thermal stresses, electrical stresses, mechanical stresses, and ambient stresses. The following are the main factors leading to mechanical stresses: winding displacement, eccentricity fault, and rotor stator collision. The rotor of the salient pole synchronous machine consists of two windings: rotor field winding and damper winding. Rotor misalignment faults in an electric machine represent the worst case of eccentricity fault, as the air gap length varies along the longitude axis of the machine.