The purpose of this thesis work was to develop an automatic fault detection system for surveillance of bearing temperature in hydropower turbines. The parameters used except the bearing temperature were cooling water temperature and cooling water flow. A simple static model based on data sampled every minute was developed to estimate the bearing temperature. Then a detector for detection of change in bearing temperature based on the CUSUM-algorithm was designed. Since the amount of data was very small the developed model was too uncertain to be used in a working system.The designed fault detection system showed to work well for the available data.

Det här examensarbetet är gjort åt Vattenfall Service Nord AB som har hand om driften för 54 vattenkraftverk i Sverige tillsammans med Vattenfall Service Syd AB. I arbetsuppgifterna för driftpersonalen ingår även jourtjänstgöring. Varje vaktutryckning som görs är kostsam. Undersökning av larm som medfört vaktutryckningar av driftpersonal till vattenkraftverk mellan 2004-01-01 ? 2005-06-30 på axel, lager och turbinsystem har gjorts.

This thesis is an evaluation of a new design concept for statorfeets in Gallejaur hydro power plant. Founder of the work is Vattenfall AB Vattenkraft. During the 70- and 80´s nuclear power began to be phased in to the Swedish grid, which meant that hydropower became an important source of rules. The generators began running in so called intermittent operations instead of basic operations, which meant 300-600 start/stop per year instead of one-ten numbers start/stop per year. In order to deal with the thermal forces that arise at every start and stop suppliers began to mount so called sliding joints, which is to take advantage of these forces and maintain the stator shape.