2-D FEM Tuned Analytical Approximation for Fringing Permeances
This paper presents an analytical approach for calculating fringing permeances in gapped inductors. For most of the gapped inductors, the permeance of other field paths out of the air gap (the fringing paths) is not negligible. Existing three-dimensional modelling techniques using finite element analysis for magnetic components are accurate, but require prohibitive amount of simulation time. Twodimensional models are often used, but the accuracy is low as a 2D simulation fails taking into account important 3D effects. We present analytical approximations for fringing permeance calculation for the most usual field patterns, denoted as basic cases. The proposed fringing coefficients can be used to present all symmetrical cases and cases with multiple air gaps. The derived equations are sufficient for a normal engineering accuracy.
KeywordsBasic Case Finite Element Method Simulation Gapped Inductor Flux Path Carter Fact
Unable to display preview. Download preview PDF.
- 1.Chew, W.M., Evans, P.D.: High-frequency inductor design concepts, in Proc. IEEE PESC’91, (1991) pp. 673–678.Google Scholar
- 2.Nysveen, A., Hernes, M.: Minimum loss design of a 100kHz inductor with foil windings, EPE93, Brighton, September 13-16, 1993, pp. 106–111.Google Scholar
- 3.Leonavicisius, V., Duffy, M., Mathuna, C.O., Boeke, U.: Comparison of different techniques to realise PFC boost inductor, APEC 2002, Dallas, USA, 10-14 March 2002, pp. 1183–1189.Google Scholar
- 5.Evans, P.D., Saied, B.M.: Calculation of effective inductance of gapped core assemblies, IEE Proceeding, vol. 133-1, (1986) pp. 41–45.Google Scholar
- 6.Chandler, P.L., Yan, X., Paterson, D.J.: Novel high-power ferrite inductor design with improved design accuracy and overall performance, IEEE 32nd Annual PESC-2001, Vol. 4, pp. 2090–2094.Google Scholar
- 7.Rahmi-Kain, A., Keyhani, A., Powell, J.: Minimum loss design of 100kHz inductor with litz wire, IEEE IAS Annual Meeting, New Orleans, October 5-9, 1997, pp. 1414–1420.Google Scholar
- 8.Hoke, A.F., Sullivan, C.R.: An improved two-dimensional numerical modeling method for E-core transforms, APEC 2002, Dallas, USA, 10-14 March 2002, pp. 151–157.Google Scholar
- 10.Kofler, H.: Force and torque in single phase pole induction motors with eccentric rotor: an attempt to include slot effects due the eccentricity, ICEM 2000, Espoo, Finland, 20-28 August 2000, pp. 1825–1828.Google Scholar
- 11.Kulda, J., Adam, J.: The magnetic field in air-gap slotted on side, Elektrotechnische Zeitschrift ETZ A, vol 91-2, (1970) pp. 109–113Google Scholar
- 12.Col. McLyman: Transformer and inductor design handbook, Marcel Dekker (1988).Google Scholar
- 13.Van den Bossche, A., Valchev, V., Filchev, T.: Improved approximation for permeances of gapped inductors, IEEE-IAS 37th Annual Meeting, Pittsburgh, PA, USA, 13-18 October, 2002Google Scholar
- 14.Meeker, D.: Finite Element Method Magnetics (FEMM), http://femm.berlios.de/.