Failure of modern hydro alternator windings insulation and their root causes

The soul part of an alternator is current carrying part that is winding. It passes through electrical, thermal and mechanical stresses during the life span of a rotatory machine. Due to prolong duration of these stresses, the insulation of a machine may deteriorate. The failure of either armature winding or field winding of an alternator makes it out of service. In result, it requires a huge amount of payment in order to replace it or repair it. In this regard, manufacturers have developed several new techniques of winding insulation in order to produce more reliable products. There are different companies who provide alternators to fulfill the customers' requirements in a tough market competition. Due to this tough market competition, each manufacture tries to provide best possible products with reasonable rate. This market competition (rate), complexity of newly developed design and customers' special requirements brought pressure over the companies which sometime result in premature failure of winding insulation. Therefore, this research work will cover in depth investigation about the insulation's failures of modern alternator windings (generators and motors).