Time-periodic finite element method for nonlinear diffusion equations

A new numerical calculation method, the time-periodic finite element method, for the nonlinear diffusion equation is proposed. In the method, the equation is closed by the periodic-time of electrical characteristics and is solved by the numerical procedure which is used not for the initial value problem but for the boundary value one. The method is applied to the calculations of the voltage across the nonlinear corona shield region of a rotating machine. The results demonstrate that the method extensively reduces the computing time without losing the accuracy compared to the conventionally used methods.