Conference Agenda

Electromagnetic interference (EMI) analysis is essential to optimize circuit designs to meet regulatory standards, especially as switching speeds in modern power electronics continue to increase. However, identifying which circuit components contribute most to EMI remains challenging. Methods like Monte Carlo simulations require thousands of runs, making them impractical for early-stage design. In this work, we demonstrate that Morris global sensitivity analysis (GSA) provides a computationally efficient alternative for screening EMI contributors. We apply Morris GSA to a buck converter simulated in LTspice with 39 variable circuit components, using the frequency-domain EMI spectrum as the output parameter. We found that only 12 optimized trajectories (480 simulations) are sufficient to obtain stable sensitivity rankings in order to identify dominant contributors to conducted emissions (differential- and common-mode) across frequency. Although Morris GSA cannot resolve higher-order interactions, our findings suggest that Morris GSA can support EMC engineers to quickly prioritize impactful design changes early in the development process.

Knowing the impedance of power converters is crucial for designing effective Electromagnetic Interference (EMI) filters and predicting EMI behaviour in system-level investigations. This paper introduces a novel impedance characterization device for power converters, designed to operate while the converter is in its active state. The device employs transformer-based injection of predefined arbitrary waveforms to capture real-time impedance measurements of the converter. A key innovation of the device is the development of a compact and cost-efficient digital amplifier, which enhances the overall efficiency of the characterization process. The device has been thoroughly tested and shown to provide accurate measurements, with performance extending up to 150 kHz, limited by the specific characteristics of the injection transformer. It has been successfully utilized to characterize both the AMN impedance and the differential-mode (DM) impedance of a single-phase converter, achieving precise and reliable results.

In this paper, we introduce an innovative methodology that combines advanced measurement techniques with 3D simulation to analyze the performance of a three-phase four-wire AC input filter from EV on-board charger (OBC). This approach not only provides a deeper understanding of filter effectiveness but also enables to identify key parameters influencing the filter's behavior in real-world applications and to propose design changes for its improvement. The performance of AC filter is evaluated for both single-phase and three-phase operation through an analysis of the common-mode (Scc21) and differential-mode (Sdd21) S-parameters. The impact of the OBC housing on filter effectiveness is thoroughly investigated and discussed.

Power electronic converters produce conducted electromagnetic interferences (EMI) on a wide frequency band. To prevent the perturbation of the electrical grid and ensure compliance of the static converter with electromagnetic compatibility (EMC) standards, EMI filters must be installed at the input of the converter. To design these filters by simulations, a high-frequency model of the entire energy conversion system is required. The model type selection is determined by whether or not the conversion system is already operational or in the design phase. For systems that are already implemented, the “Terminal Modeling” (TM) approach, which considers the converter and its load as a black-box or gray-box model, is particularly well-suited. In this study, due to the drawbacks of the “black box” model, we propose to use a “gray box” model for a DC-DC conversion system. The aim is to improve methods for experimental identification of parameters for these models. The simulation results of the conducted emissions will be compared with those measured in the frequency band from 1 MHz to 100 MHz.