Estimating Lifetimes for Stator Windings in Hydropower Generators

Today the availability of a hydropower plant is more important than ever. In a high voltage power generator one of the most critical components is the stator winding. The cost of a stator winding breakdown is extensive, both when it comes to restoration and outage in production. However, nobody wants to change the stator winding if it is not necessary. During the last decades intermittent operation has increased, which has lead to greater strains on the stator windings. Combined with the increased need for availability, this means that a good estimation of the lifetime of a stator winding is crucial. In this broad investigation, several methods are presented, such as an algorithm based on Bayesian method, multiple regression analysis, and various diagnostic methods. It has been found that generator design, diagnostic data, and power plant operation all are important parameters when estimating lifetimes, thus must several methods be considered