A comparison of the ladder and full-order magnetic models

Predictions of the reduced-order ladder model and the full-order extended cantilever model are compared with the measured behavior of an experimental multiple-output flyback converter. The flyback transformer geometry was chosen to closely follow the idealizing assumptions that lead to the ladder approximation, including use of a pot core with full-width copper foil windings. In spite of this, the ladder model fails to predict the observed waveforms and the mode of operation. The full-order extended cantilever model does indeed correctly predict the operating mode and the observed waveforms. Model parameters are measured using a network analyzer. Conditions on the validity of these measurements are derived using Middlebrook's extra element theorem.

[1]  Dragan Maksimovic,et al.  Modeling of cross-regulation in multiple-output flyback converters , 1999, APEC '99. Fourteenth Annual Applied Power Electronics Conference and Exposition. 1999 Conference Proceedings (Cat. No.99CH36285).

[2]  William M. Polivka.  Applications of Magnetics to Problems in Switched-Mode Power Conversion , 1984 .

[3]  Abraham Dauhajre,et al.  Modelling and estimation of leakage phenomena in magnetic circuits , 1986, 1986 17th Annual IEEE Power Electronics Specialists Conference.

[4]  Robert W. Erickson,et al.  A multiple-winding magnetics model having directly measurable parameters , 1998, PESC 98 Record. 29th Annual IEEE Power Electronics Specialists Conference (Cat. No.98CH36196).

[5]  Robert W. Erickson,et al.  Modeling of cross-regulation in converters containing coupled inductors , 2000 .

[6]  F. M. Starr.  Equivalent circuits , 1932, Electrical Engineering.

[7]  R. D. Middlebrook,et al.  Null double injection and the extra element theorem , 1989 .

[8]  Slobodan Cuk,et al.  Isolation and multiple output extensions of a new optimum topology switching DC-to-DC converter , 1978, 1978 IEEE Power Electronics Specialists Conference.

[9]  Robert W. Erickson,et al.  Modeling of cross-regulation in converters containing coupled inductors , 1998, APEC '98 Thirteenth Annual Applied Power Electronics Conference and Exposition.