reduction on the outpower of one water turbine generator

[181273]

hello, here´s Jose from sunny Spain, and I got another question relative to the generation thing... I got one generator 1000 kw at full output power, and after ten hours more or less, the output start to decrease, and stay on 960 kw....

The customer tell me that in other power plants, there´s a trick, consisting on mantein the output power less as posible, and then go again to full power, and this is like a "group cleaning", something relative to magnetism...

On my opinion this is stupid, but i´ll like to know your opinion.

 

[jraef]

What type of generator is it?

 

[181273]

It´s a syncronous generator, 1000 rpm,1000 kw, cos 0,9, and the regulator is a basler decs 125....and the turbine is a Kaplan one..... does somebody knows something about the cleaning of the generator flux????

 

[waross]

I would forget flux cleaning and look for water restrictions or a low water level. Another possibility is trash buildup that clears under low flow conditions (low output).
It may be that some trash has started cavitation which then continues until it is interupted by a low flow. The machine would then deliver 100% until another tramp object in the water flow re-started cavitation.
respectfully