Segmentation Effects in the Modular HVDC Offshore Wind Generator and its Impact on Losses

Abstract

Worldwide wind power capacity jumped from 7.5 GW in 1997 to 564GW by 2018, according to IRENA. Many regions of the world have strong wind speeds, but the best locations for generating wind power are often remote, where offshore wind power offers tremendous potential. This paper presents a concept to remove the use of offshore platforms/substations, constituting the energy conditioning element for the high voltage direct current (HVDC) transmission. Instead, it connects converters in a series of modules for a segmented HVDC generator, which limits the number of conversion steps. Our work focuses on the impact of segmentation on loss and is validated numerically using finite element analysis (FEA) and analytical solutions. The machine’s geometry, design constraints, design procedure, loss calculations, and numerical analysis are included. Three different methods are presented and used to determine the core losses. The paper highlights the increase in core losses due to airgap segmentation. We show that Zhang’s method yield the largest deviation in the loss calculations, i.e., 15.812 %, 16. 410% and 15. 894% increase in core losses for 10, 20 and 30mm segment airgaps, respectively.