Johannes H. J. Potgieter

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This paper deals with the modeling, the design, and the construction of a new concept slip-synchronous permanent-magnet (PM) wind generator for direct-drive direct grid connection. This generator is a variation of the conventional PM induction generator concept as proposed and analyzed in literature. The use of nonoverlap windings is proposed for the first(More)
The main focus of this paper is cost-effective techniques to reduce the cogging torque in permanent magnet (PM) wind generators. However, there are also certain limits with which other machine design aspects need to comply. These aspects include ease of manufacturing, mass, load torque ripple, and voltage quality. In this paper, a low-cost single layer PM(More)
Due to the short end windings of nonoverlap winding permanent-magnet (PM) machines, the end-winding inductance component is generally ignored in the design. In most cases, the end-flux fringing effects in PMs are also not taken into account. It is shown in this paper that these end effects have a significant influence on the performance parameters of the(More)
In order to simplify and increase the reliability of wind generators, a new type of a direct-drive directly grid-connected wind generator known as a slip-synchronous permanent-magnet generator (SS-PMG) is proposed. It consists of two integrated generating units, i.e., a directly turbine-connected slip PMG unit and a directly grid-connected PM synchronous(More)
With eddy-current couplings proposed for and applied in several industrial applications, it is essential that these types of electrical machines be more thoroughly evaluated. In this paper, the feasibility of replacing the classical eddy-current coupling topology with a toothed slip permanent magnet coupling (PMC) is investigated. The case study application(More)
The focus of the study in this paper is on the design of unconventional directly grid-connected PM wind generators without power electronic converters. As a case study, this analysis is based on a novel direct-drive wind generator system known as a slip-synchronous permanent-magnet (PM) wind generator. Attention is given to the definition of the design(More)
The double rotor, toothed, toroidal-winding permanent-magnet (PM) machine is not a well known concept and has received very limited attention in literature. In this study, the concept is proposed for use as a direct-drive wind generator. Due to the varying design requirements of wind generators over the different power ranges, the PM generator is optimized(More)
This paper forms part of a broader study on the design optimisation of a high speed switched reluctance motor for automotive traction applications. Due to the high speed operation and resulting high electrical frequency it is of extreme importance that the different loss components of this motor are accurately calculated. In this study several effects are(More)
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