# Multirate PWM balance method for the efficient field-circuit coupled simulation of power converters

## TL;DR

This paper introduces the multirate PWM balance method, an efficient simulation technique for power converters that separates different time scales using new PWM eigenfunctions, reducing computational cost in field-circuit coupled simulations.

## Contribution

The paper presents a novel multirate PWM eigenfunction approach that decouples equations, enabling more efficient field-circuit coupled simulations of power converters with idealized switches.

## Key findings

- Significantly reduces simulation time for power converters.
- Accurately captures steep transients with larger time steps.
- Demonstrates effectiveness through numerical examples.

## Abstract

The field-circuit coupled simulation of switch-mode power converters with conventional time discretization is computationally expensive since very small time steps are needed to appropriately account for steep transients occurring inside the converter, not only for the degrees of freedom (DOFs) in the circuit, but also for the large number of DOFs in the field model part. An efficient simulation technique for converters with idealized switches is obtained using multirate partial differential equations, which allow for a natural separation into components of different time scales. This paper introduces a set of new PWM eigenfunctions which decouple the systems of equations and thus yield an efficient simulation of the field-circuit coupled problem. The resulting method is called the multirate PWM balance method.