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Finite Elements in Electromagnetics 3. Eddy currents and skin effect. Oszkár Bíró IGTE, TU Graz Kopernikusgasse 24Graz, Austria email: biro@igte.tu-graz.ac.at. Overview. Eddy current problems Formulations in eddy current free regions Formulations in eddy current regions
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Finite Elements in Electromagnetics3. Eddy currents and skin effect Oszkár Bíró IGTE, TU Graz Kopernikusgasse 24Graz, Austria email: biro@igte.tu-graz.ac.at
Overview • Eddy current problems • Formulations in eddy current free regions • Formulations in eddy current regions • Coupling of formulations • Skin effect problems • Voltage excitation, A,V-A formulation • Current excitation, T,F-F formulation
Typical eddy current problem Wn: nonconducting region Air Coil J(r,t) = 0 J(r,t) known Wc: eddy current region J(r,t) unknown
Voltage excitation (1) , in in , , in in , , on on on or and are continuous on
Boundary value problem for A,V (1) Differential equations: in Wc, in Wn,
Boundary value problem for A,V (2) Boundary conditions: , on , on . on or Interface conditions: . are continuous on and
Current excitation (1) , in . in , in , in or , on . on are continuous and and F
Properties of T0 , in is continuous on
A possible choice of T0 Solve the static current field in Wc
Boundary value problem for T,F (1) Differential equations: in Wc, in Wn,
, on Boundary value problem for T,F (2) Boundary conditions: on . on . or Interface conditions: . are continuous on and