Influence of IGBT Switching Behavior on Conducted and Radiated Emissions below 30 MHz

This study examines the influence of switching behavior on conducted and radiated emissions below 30 MHz. A prototype buck converter with a 300 A / 1200 V IGBT module is used, and its switching behavior is modified using a resistive active gate control driver. Time-domain measurements reveal a direct relationship between switching behavior and conducted emissions, as well as magnetic and electric radiated emissions in the frequency range from 10 MHz to 30 MHz. S-shape gate control using an active gate control method effectively reduces initial dV/dt and voltage oscillations. S-shape gate control achieves 22% to 27% reduction in switching loss without increasing conducted and radiated emission levels. However, this reduction is not observed from dV/dt-switching loss trade-off. These results show the limitations of using dV/dt only as an EMI indicator. Therefore, this paper proposes a new trade-off indicator, the EMI-switching loss trade-off indicator. The results highlight the importance of advanced control strategies to meet standardized electromagnetic compatibility requirements while optimizing the performance of semiconductor power devices.