Nonlinear time-domain formulation of the method of moments

In this paper a time domain formulation of the method of moments for the analysis of nonlinear materials is presented. The magnetization vector M and the nonlinear constitutive equation H=H(B) are used in order to express the magnetic vector potential as a function of conduction currents only. The Lorentz gauge is used in order to express the scalar potential as a function of the vector potential. By combining the electric field definition and Ohm´s law an integral equation in the conduction current unknowns is obtained. The method of moments is then applied to this equation. The use of pulse functions as subsection bases allows a quick matrix set up especially when regular volume shapes are selected. Calculated results are compared with results obtained with other methods relating to benchmark problems