Illustration of a water turbine and generator.
When a power plant gets a new generator, it comes with some spare parts, usually spare stator rods. These spare rods are often stored for decades before they are needed. Then they can be exposed to both moisture and temperature fluctuations, which affect the rods' electrical properties.
If the stator rods in the generator need to be replaced, the spare rods are often inserted without testing their condition. In the worst case, a defective spare rod can lead to a shutdown. It threatens security of supply and can cause major financial losses for the power plant.
No established standard
Despite the extensive consequences that bad or defective spare rods can cause, there is currently no established standard for testing spare rods.
The results from HydroCen can do something about that. In the project "Turbine and Generator Lifetime", the researchers have developed a proposal for a test procedure that can be used to distinguish spare rods with good electrical properties from those with poor ones. The method is both simple and fast.
The researchers Arne Nysveen, Henrik Enoksen, Espen Eberg and Emre Kantar asked Norwegian power plants how they store their spare rods and found that there was great variation. They therefore tested how different storage conditions affect the electrical properties of the rods. In addition, they have looked at the lifetime of the rods in relation to the increasing use of power driving, which is production with a lot of start/stop.