A Fast and Accurate Field–Circuit Cosimulation Method in Time Domain Based on Model Order Reduction Technique

A critical challenge faced by conventional time-domain algorithms is that for models with slow energy decay (requiring long simulation times to reach steady states), even implicit time-stepping schemes inevitably lead to a large number of time iterations. For problems with millions or even tens of millions of degrees of freedom (DOFs), the computational cost of time-stepping in traditional implicit time-domain algorithms becomes prohibitively high. In this letter, a fast and accurate field–circuit cosimulation method based on model order reduction (MOR) technique in the time domain is proposed. The advantage of MOR techniques in the time domain lies in their ability to accelerate the time-stepping process. A key challenge in this method arises from the frequency-dependent nature of the impedance boundary condition (IBC) used for modeling the conductor loss, which requires specialized handling in time-domain MOR algorithms. In addition, the field–circuit cosimulation is implemented by calling the SPICE software.