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Your search keyword '"Ferreira, Jan A."' showing total 328 results
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328 results on '"Ferreira, Jan A."'

120. Trends in Wind Turbine Generator Systems

Author

Polinder, Henk, primary, Ferreira, Jan Abraham, additional, Jensen, Bogi Bech, additional, Abrahamsen, Asger B., additional, Atallah, Kais, additional, and McMahon, Richard A., additional

Published
2013
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148. Analysis and Neutral Voltage-Based Detection of Interturn Faults in High-Speed Permanent-Magnet Machines With Parallel Strands.

Author

van der Geest, Martin, Polinder, Henk, Ferreira, Jan Abraham, Veltman, Andre, Wolmarans, Johan J., and Tsiara, Nefeli

Subjects
ALTERNATING current machinery, FINITE element method, PERMANENT magnets, SHORT circuits, PERMANENT magnet generators
Abstract

This paper analyzes short circuits in high-speed permanent-magnet (PM) machines. Analytical models are used to estimate the consequences of single-strand, parallel-strand, and phase-to-phase turn-to-turn short circuits, as well as open-circuit faults. The parameters for the analytical models are obtained from 3-D finite-element simulations and consider the actual position of each strand inside the slot. It is shown that parallel-strand short circuits are less severe than single-strand short circuits, both before and after fault mitigation actions. The potential for large fault current densities in high-speed PM machines is also demonstrated, with measured rms current densities up to 450 \A/mm^2 . A simple fault detector based on the synchronous detection of the machine and inverter neutral voltage difference is proposed, which is suitable for hardware implementation and can function as an independent observer of a drive system. The dependence of the detectability on the short circuit location and the effects of natural imbalances on the detector output are investigated. Experiments are performed to demonstrate the concept, showing that faults of at least 0.4% can be detected. [ABSTRACT FROM PUBLISHER]

Published
2015
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150. A novel and simple method to distinguish winding loss from inductor loss under practical excitations.

Author

Wenbo Wang, de Haan, Sjoerd, Ferreira, Jan A., and Pansier, Frans

Abstract

Previous methods for measuring magnetic core loss are either only suitable for sine wave excitations or cannot separate winding loss from inductor loss. In this paper, we present a new method to distinguish winding loss from inductor loss under practical excitations. This method utilizes a converter to generate the actual excitation waveforms and uses a calorimetric setup to quantify the losses. By splitting up the inductor in a converter into an air core inductor and a magnetic core inductor, both equipped with exactly the same winding structure, the air core inductor loss can be used as the reference of the magnetic cored inductor winding loss. In this way, magnetic core losses can be determined in the actual operation condition of a converter in which the inductor is to be used. The method requires simple setup and is easy to execute. It worked well in assessing different magnetic core materials. [ABSTRACT FROM PUBLISHER]

Published
2013
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