Forces and vibrations in a Modular HVDC Generator

MSc thesis of Casper Klop

This thesis studies the forces and vibrations in a Modular HVDC Generator, designed to improve the integration of offshore wind farms into the electricity grid. By segmenting the stator of a 10 MW Direct-Drive generator, and connecting a Power Electronic Converter to each insulated segment, HVDC can be produced directly inside the nacelle. Using both analytical methods and COMSOL, this segmentation was found to increase the cogging torque and several low-order force harmonics. Furthermore, using modal analysis, it was found that the structural integrity of the stator is significantly reduced. Combining the electromagnetic and mechanical analysis, several design recommendations are given to enable a feasible design.