Importance of Interface Variables for Closed-Loop Circuit EMC Co-Simulation Using WR Method

This article highlights the importance of interface variables (IVs) for closed-loop co-simulating power converter controllers and electrical circuits using waveform relaxation (WR). The method enhances co-simulation performance and stability by adjusting relaxation parameters in parallel with the behavioral source. Testing is conducted on a buck converter circuit with an input voltage ranging from 4 to 6 V and an output voltage of 3.3 V. Comparative analysis with conventional WR indicates a voltage difference of less than 1.8% between direct and measured values after 24 iterations and 38.25 s elapsed time. An assessment of the suitability of this method to evaluate the conducted electromagnetic immunity of the converter is also provided. These results highlight the proposed method's ability to achieve faster and more accurate convergence compared to traditional WR methods.