Design Concepts for High-Voltage Variable-Capacitance DC Generators

• Published in: IEEE transactions on industry applications Vol. 45; no. 5; pp. 1778 - 1784
• Main Authors: O'Donnell, R., Schofield, N., Smith, A.C., Cullen, J.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.09.2009; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: AC-DC power converters; Costs; DC generators; Density; Electrostatic machines; Generators; HVDC generator; HVDC transmission; Marine technology; off-shore wind generation; Offshore; Offshore engineering; Offshore structures; Power generation; Proposals; Underwater cables; variable-capacitance dc generator; variable-capacitance machines; Wind energy generation; Wind farms; Wind power generation
• ISSN: 0093-9994; 1939-9367
• DOI: 10.1109/TIA.2009.2027545

The transmission requirements of the next generation of offshore wind farms, such as the Round Two U.K. offshore development proposals, may rely on high-voltage direct current (HVDC) technology for at least a part of their power collection and transmission requirements. HVDC technology is particularly suited for the transmission of high powers through large lengths of submarine cables; however, its application is limited by the high cost of offshore ac-dc converter stations. This paper therefore investigates the feasibility of the direct generation of HVDC power using a novel generator topology, as an alternative solution to the generation-transmission requirements of large offshore wind farms. A variable-capacitance generator uses electrostatic fields to generate an HVDC output with a minimum of power conditioning and is based on a previous work that suggests system power densities comparable with the conventional generator-transformer-rectifier systems to be achievable.