Optimised High Frequency Transformer Design with Arbitrary Current Waveforms

John Breslin, Prof. W. G. Hurley

Switching circuits, operating at high frequencies, have led to considerable reductions in the size of magnetic components and power supplies. Non-sinusoidal voltage and current waveforms and high frequency skin and proximity effects contribute to transformer losses. Traditionally, transformer design has been based on sinusoidal voltage and current waveforms operating at low frequencies. The physical and electrical properties of the transformer form the basis of a anew design methodology while taking full account of the type of current and voltage waveforms and high frequency effects. Core selection is based on the optimum throughput of energy with minimum losses. The optimum core is found directly from the transformer specifications: frequency, power output and temperature rise. The methodology is suitable for use in a computer application in conjunction with a database of core and winding materials. High frequency AC loss effects must then be taken into account. The AC losses due to non-sinusoidal current waveforms have traditionally been found by calculating he losses at harmonic frequencies when the Fourier coefficients are known. An optimised foil or layer thickness in a winding may be found by applying the Fourier analysis over a range of thickness value. New methodologies have been developed to find the optimum foil or layer thickness for any periodic waveshape, without the need for calculation of AC losses at harmonic frequencies. The first methodology requires the RMS value of the current waveform and RMS value of its derivative. The second methodology makes use of regression analysis and some harmonic summations.

Start date: 1st of September 1994. This project has been completed.

Project collaborators: Enterprise Ireland

Project Publications

Journal
J. Breslin, W. G. Hurley, "Critical Choices in a System for Optimized Design of Arbitrary Waveform Transformers", Journal of Circuits, Systems, and Computers, vol. 13, no. 4, pp. 919-928, August 2004
W. G. Hurley, E. Gath, J. Breslin, "Optimizing the A.C. Resistance of Multilayer Transformer Windings with Arbitrary Current Waveforms", IEEE Trans. on Power Electronics, vol.15, no. 2, pp. 369-376 (Transaction Prize Paper) also in 30th IEEE Power Electronics Specialists Conference, PESC'99, Charleston, SC, vol. 1, pp. 580-585, June 1999, March 2000.
W. G. Hurley, W. Wolfle, J. Breslin, "Optimized Transformer Design: Inclusive of High Frequency Effects", IEEE Trans. on Power Electronics, vol. 13, no. 4, pp. 651-659, July 1998.

Conference
J. Breslin, W. G. Hurley, "A Web-Based System for Transformer Design", Proceedings of the 7th International Conference on Knowledge-Based Intelligent Information and Engineering Systems, KES'2003, University of Oxford, pp. 715-721, September 2003.
J. Breslin, W. G. Hurley, "Computer Aided High Frequency Transformer Design Using an Optimized Methodology", Proceedings of the 7th IEEE Workshop on Computers in Power Electronics, COMPEL 2000, Blacksburg, Virginia, pp. 268-271, July 2000.
J. Breslin, W. G. Hurley, "Derivation of Optimum Winding Thickness for Duty Cycle Modulated Current Waveshapes", 28th IEEE Power Electronics Specialists Conference, PESC'97, St. Louis, MO, vol. 1, pp. 655-661, June 1997.
J. Breslin, W. G. Hurley, "A Novel Optimisation Scheme for Designing High Frequency Transformer Windings", 31st Universities Power Engineering Conference, UPEC'96, Crete, vol. 1, pp. 465-468, September 1996.
J. Breslin, W. G. Hurley, "Design of Magnetic Components Using a Graphical Interface: Inclusive of High Frequency Effects", 30th Universities Power Engineering Conference, UPEC'95, University of Greenwich, London, vol. 1, pp. 347-350, September 1995.

• Disclaimer
• Privacy
• Copyright
• Accessibility