Inductance Computation for 2D and 3D Transient Solutions

Because both 2D and 3D transient solutions are nonlinear, for inductance computation, Maxwell provides two options: apparent inductance and incremental inductance. After the FEA normal solution is completed at each timestep, the permeability associated with apparent inductance, or the differential permeability associated with incremental inductance, of each element, is frozen – which is equivalent to freezing the coefficient matrix (the left side of the equation to be solved). In order to obtain winding self-inductance and mutual inductance, the solver sets an excitation current of 1 A in the first winding, while setting all other winding currents to zero (permanent magnet effects are excluded). This excitation assignment corresponds to one source vector on the right-hand side of the equation to be solved. As a result, the calculated flux linkage provides the self-inductance for the first winding with 1 A excitation current, and the calculated flux linkages represent mutual inductance for all other windings with zero current. Next, the solver excites the second winding with a current of 1 A, while setting all other winding currents to zero (permanent magnet effects are excluded). This excitation assignment corresponds to another source vector on the right-hand side of the equation to be solved. The solver continues this process until all windings have been assigned 1 A current in turn.

Related Topics 

Matrix Computation Tab Settings for Transient Solutions