A numerical study of the coupling coefficients for pot core transformers
- Kansas State Univ., Manhattan, KS (United States)
When a circuit containing a transformer is to be simulated, one must know the coupling coefficient or equivalent leakage inductances in addition to the other transformer properties. When other inductances in series with a transformer winding are large compared to the leakage inductance the leakage inductance may be neglected in a simulation. Otherwise, the coupling coefficient must be known or the simulation will be inaccurate. Since the degree of coupling depends on the nature of the winding as well as the core, and is difficult to estimate accurately, the authors have used numerical techniques to study the trends in coupling with geometric parameters for cores having cylindrical symmetry. Magnetic vector potential has been found using the TOPAZ2D finite element code, and then correspondingly interpolated numerical integration has given the inductances for an equivalent circuit. Results from the calculations show that although the magnetizing inductance changes greatly as a core saturates, the coupling coefficient changes slowly so long as some reasonable effective permeability remains. Actual values depend on the turns ratios and any air gaps present. For a typical pot core geometry without an air gap the coupling coefficient ranges from 0.997 to 0.999 for effective permeabilities from 600 to 1,800. With air gaps the coupling coefficient drops, but stays even more constant with permeability.
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 64577
- Journal Information:
- IEEE Transactions on Magnetics, Vol. 31, Issue 3Pt2; Other Information: PBD: May 1995
- Country of Publication:
- United States
- Language:
- English
Similar Records
NEW METHOD OF CONSTRUCTING A MULTILIMB MAGNET CORE OF A BETATRON
A three-phase three-winding core-type transformer model for low-frequency transient studies