On a request from the water sewage plant Gryaab in Gothenburg a power quality survey was performed. The voltages and currents have continuously been sampled in the incoming 10 kV substation HSP01 from April-August 2008. Power quality measurements were also performed in Gryaabs other 10 kV substation HSP04 fed from HSP01 and at the terminals of the induction motor IN_PU4040 of 1.3 MW which controls one of the four large inflow pumps to the plant. The reason for the latter measurement was due to registered negative transients each time the motor was connected to the grid. The cause of the transients could be explained by the coupling in the substation, the ageing of the motor which could result in damage of the bearings or resonance in the motor circuit which amplifies high frequency harmonics.

On a request from the water sewage plant Gryaab in Gothenburg a power quality survey wasperformed. The voltages and currents have continuously been sampled in the incoming 10 kVsubstation HSP01 from April-August 2008. Power quality measurements were also performedin Gryaabs other 10 kV substation HSP04 fed from HSP01 and at the terminals of theinduction motor IN_PU4040 of 1.3 MW which controls one of the four large inflow pumps tothe plant. The reason for the latter measurement was due to registered negative transients eachtime the motor was connected to the grid. The cause of the transients could be explained by thecoupling in the substation, the ageing of the motor which could result in damage of thebearings or resonance in the motor circuit which amplifies high frequency harmonics.

On a request from the water sewage plant Gryaab in Gothenburg a power quality survey was performed. The voltages and currents have continuously been sampled in the incoming 10 kV substation HSP01 from April-August 2008. Power quality measurements were also performed in Gryaabs other 10 kV substation HSP04 fed from HSP01 and at the terminals of the induction motor IN_PU4040 of 1.3 MW which controls one of the four large inflow pumps to the plant. The reason for the latter measurement was due to registered negative transients each time the motor was connected to the grid. The cause of the transients could be explained by the coupling in the substation, the ageing of the motor which could result in damage of the bearings or resonance in the motor circuit which amplifies high frequency harmonics.

On a request from the water sewage plant Gryaab in Gothenburg a power quality survey was performed. The voltages and currents have continuously been sampled in the incoming 10 kV substation HSP01 from April-August 2008. Power quality measurements were also performed in Gryaabs other 10 kV substation HSP04 fed from HSP01 and at the terminals of the induction motor IN_PU4040 of 1.3 MW which controls one of the four large inflow pumps to the plant. The reason for the latter measurement was due to registered negative transients each time the motor was connected to the grid. The cause of the transients could be explained by the coupling in the substation, the ageing of the motor which could result in damage of the bearings or resonance in the motor circuit which amplifies high frequency harmonics.

On a request from the water sewage plant Gryaab in Gothenburg a power quality survey wasperformed. The voltages and currents have continuously been sampled in the incoming 10 kVsubstation HSP01 from April-August 2008. Power quality measurements were also performedin Gryaabs other 10 kV substation HSP04 fed from HSP01 and at the terminals of theinduction motor IN_PU4040 of 1.3 MW which controls one of the four large inflow pumps tothe plant. The reason for the latter measurement was due to registered negative transients eachtime the motor was connected to the grid. The cause of the transients could be explained by thecoupling in the substation, the ageing of the motor which could result in damage of thebearings or resonance in the motor circuit which amplifies high frequency harmonics.

On a request from the water sewage plant Gryaab in Gothenburg a power quality survey wasperformed. The voltages and currents have continuously been sampled in the incoming 10 kVsubstation HSP01 from April-August 2008. Power quality measurements were also performedin Gryaabs other 10 kV substation HSP04 fed from HSP01 and at the terminals of theinduction motor IN_PU4040 of 1.3 MW which controls one of the four large inflow pumps tothe plant. The reason for the latter measurement was due to registered negative transients eachtime the motor was connected to the grid. The cause of the transients could be explained by thecoupling in the substation, the ageing of the motor which could result in damage of thebearings or resonance in the motor circuit which amplifies high frequency harmonics.

On a request from the water sewage plant Gryaab in Gothenburg a power quality survey wasperformed. The voltages and currents have continuously been sampled in the incoming 10 kVsubstation HSP01 from April-August 2008. Power quality measurements were also performedin Gryaabs other 10 kV substation HSP04 fed from HSP01 and at the terminals of theinduction motor IN_PU4040 of 1.3 MW which controls one of the four large inflow pumps tothe plant. The reason for the latter measurement was due to registered negative transients eachtime the motor was connected to the grid. The cause of the transients could be explained by thecoupling in the substation, the ageing of the motor which could result in damage of thebearings or resonance in the motor circuit which amplifies high frequency harmonics.

On a request from the water sewage plant Gryaab in Gothenburg a power quality survey wasperformed. The voltages and currents have continuously been sampled in the incoming 10 kVsubstation HSP01 from April-August 2008. Power quality measurements were also performedin Gryaabs other 10 kV substation HSP04 fed from HSP01 and at the terminals of theinduction motor IN_PU4040 of 1.3 MW which controls one of the four large inflow pumps tothe plant. The reason for the latter measurement was due to registered negative transients eachtime the motor was connected to the grid. The cause of the transients could be explained by thecoupling in the substation, the ageing of the motor which could result in damage of thebearings or resonance in the motor circuit which amplifies high frequency harmonics.

On a request from the water sewage plant Gryaab in Gothenburg a power quality survey wasperformed. The voltages and currents have continuously been sampled in the incoming 10 kVsubstation HSP01 from April-August 2008. Power quality measurements were also performedin Gryaabs other 10 kV substation HSP04 fed from HSP01 and at the terminals of theinduction motor IN_PU4040 of 1.3 MW which controls one of the four large inflow pumps tothe plant. The reason for the latter measurement was due to registered negative transients eachtime the motor was connected to the grid. The cause of the transients could be explained by thecoupling in the substation, the ageing of the motor which could result in damage of thebearings or resonance in the motor circuit which amplifies high frequency harmonics.

I de nordliga regionerna förekommer kallt klimat under vinterhalvåren. Som en följd bildas is i älvarna vilket kan påverka produktionen för ett vattenkraftverk negativt. Vattenfall AB äger en mängd vattenkraftverk som årligen drabbas av produktionsförluster under vintertiden. Syftet med detta examensarbete är därför att kvantifiera och analysera Vattenfalls isrelaterade produktionsförluster inom de svenska gränserna. Huvudsakligen behandlar denna rapport de fallförluster som isen orsakar över intagsgrindarna och i älvsträckorna nedströms Vattenfalls vattenkraftstationer.

On a request from the water sewage plant Gryaab in Gothenburg a power quality survey wasperformed. The voltages and currents have continuously been sampled in the incoming 10 kVsubstation HSP01 from April-August 2008. Power quality measurements were also performedin Gryaabs other 10 kV substation HSP04 fed from HSP01 and at the terminals of theinduction motor IN_PU4040 of 1.3 MW which controls one of the four large inflow pumps tothe plant. The reason for the latter measurement was due to registered negative transients eachtime the motor was connected to the grid. The cause of the transients could be explained by thecoupling in the substation, the ageing of the motor which could result in damage of thebearings or resonance in the motor circuit which amplifies high frequency harmonics.

On a request from the water sewage plant Gryaab in Gothenburg a power quality survey was performed. The voltages and currents have continuously been sampled in the incoming 10 kV substation HSP01 from April-August 2008. Power quality measurements were also performed in Gryaabs other 10 kV substation HSP04 fed from HSP01 and at the terminals of the induction motor IN_PU4040 of 1.3 MW which controls one of the four large inflow pumps to the plant. The reason for the latter measurement was due to registered negative transients each time the motor was connected to the grid. The cause of the transients could be explained by the coupling in the substation, the ageing of the motor which could result in damage of the bearings or resonance in the motor circuit which amplifies high frequency harmonics.

Optimization of soil tillage and crop rotation is important in many aspects, but particularly in maximizing profit margins. Since the economic outcome is usually decisive, it can be interesting to study different combinations of soil tillage systems and crop rotations in order to identify the maximum economic outcome. How a crop functions in a particular tillage system determines whether it is profitable to grow that crop. Different tillage systems affect the soil and its processes in different ways. Reduced tillage often works best on weak-structured heavy clays and on silty clays.

Modern sawmills are using the raw-material and the production-capacity more efficiently today, due to rising raw-material prices and higher production costs. Log sweepness has a negative effect on the sawn yield, for sawmills with straight-sawing. It is desirable that these logs could be sorted based on more criteria, if it increases value-yield and consequently the utilization of raw-material. Bow-heights over 1 cm have a negative effect on sawn yield, since the surface of the mantle cuts down in the sawn pattern. Some of these small bow-heights reduce the logs yield of value which affects the production planning negatively. Nearly half of all the Swedish logs have a bow-height over 1 cm.

Glaciologer har under en längre tid observerat förändringar av glaciärer på Svalbard, att några minskar i storlek och att vissa växer. Avsmältning med ökade havsnivåer och potentiellt ändrad havscirkulation till följd är ett scenario som berör människor över hela värden. Dessa förändringar kan eventuellt förklaras genom att koppla de meteorologiska förhållandena i området till större cirkulationsförändringar.De meteorologiska förhållandena över Svalbard har simulerats med en regional klimatmodell, WRF (Weather Research Forecasting), för tre domäner med upplösningarna 24 km, 8 km och 2,7 km. Modellen har testats i två versioner, standard-WRF med förvalda processbeskrivningar och WRF med processbeskrivningar anpassade för polärt klimat och har drivits med ERA-Interim data, som är en återanalys av de globala väderförhållandena framtagen av ECMWF. Resultaten från WRF har verifierats mot observationer uppmätta av AWS-stationer (Automatic Weather Station).