M.Ing (Electrical and Electronic Science) / High frequency magnetic components have significant advantages related to cost and physical size compared to their low frequency counterparts. The advent of high frequency power switch technology made the transformer frequency a variable and recent advances in this field have been ever pushing the switching frequency of higher power converters. Although high frequency inductors and transformers have been used and applied extensively to an increasingly broad range of applications over recent decades, analysis and design of these devices involves certain difficulties, related to extra losses due to eddy currents as well as smaller cooling surfaces, to the developer and designer. Numerical simulations of eddy currents in windings are slow, if not impossible in many cases, due to the large mesh impositions required in order to converge. Eddy currents and thermal constraints impose limitations on flux- and current densities, complicating the design. As yet, a convenient means of design, analysis and optimization of the physical magnetic topology does not exist. In this study, a method for analysing eddy currents in windings, usmg a combined analytical and numerical approach, is presented and implemented in a CAD tool. The one dimensional solutions for eddy currents in strip conductors are written in a more flexible form. A new approach to magnetic component design, called scant modelling, is presented and applied to two practical examples. The scant model comprises a minimum number of functional and form parameters in analysing and optimizing a design, but considers eddy current effects, thermal constraints and the effects of physical size and shape of core and windings at high frequencies.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uj/uj:4327 |
| Date | 13 March 2014 |
| Creators | Odendaal, Willem Gerhardus |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
| Rights | University of Johannesburg |
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