WYLLIE, PETER,BRUCE (2014) Electrothermal Modelling for Doubly Fed Induction Generator Converter Reliability in Wind Power. Doctoral thesis, Durham University.
Increased reliance upon renewable energy sources, chiefly wind, places a growing emphasis on the reliability of the technology used in Wind Turbines. The current Wind Turbine fleet is dominated by the Doubly Fed Induction Machine WT, which utilises a partially rated power electronic converter to vary the speed of the rotor and thus ensure the maximum energy capture available from the wind. This converter is associated with a significant percentage of WT failures. This thesis examines the low frequency temperature cycling occurring in one half of the back to back converter which results in a high failure rate of the rotor side converter as compared to the grid side converter. To this end a MATLAB/PLECS model was constructed to demonstrate the temperature cycling occurring in a 2.5MW DFIG WT. Lifetime of the semiconductor devices was extrapolated. An adaptation to the standard Maximum Power Point Tracking control method was suggested in which the lowest operating frequencies (less than 2.33Hz) were avoided. In doing so, lifetime was observed to increase at a minor cost to energy yield from the WT.
|Item Type:||Thesis (Doctoral)|
|Award:||Doctor of Philosophy|
|Keywords:||Wind Energy, DFIG, Power electronics, Reliability, thermal modelling, lifetime modelling|
|Faculty and Department:||Faculty of Science > Engineering and Computing Science, School of|
|Copyright:||Copyright of this thesis is held by the author|
|Deposited On:||12 Dec 2014 10:29|