A non-linear coupled 3D model for magnetic field and electric circuit equations

The authors propose a 3-D numerical model in which the magnetic field and electric circuit equations in the absence of eddy currents are solved simultaneously. To consider the magnetic equations, use is made of a magnetic vector potential formulation with the gauge condition (A.w=0) which makes it possible to reduce the number of unknowns. To take into account the magnetic and electric nonlinearities, the Newton-Raphson algorithm has been used. Two applications have been considered: an iron core coil fed by sinusoidal voltage through a diode and a current transformer. For the latter example the results obtained from the simulation are compared with experimental ones