Abstract: Static converters have seen major advancements in efficiency and compactness, but remain a primary source of conducted and radiated electromagnetic disturbances, particularly during semiconductor switching events. These disturbances propagate through parasitic elements and must comply with electromagnetic compatibility (EMC) standards to ensure safe coexistence with other systems. This work presents a detailed experimental investigation of conducted electromagnetic interference (EMI) in a series chopper, with a focus on distinguishing and quantifying common-mode (CM) and differential-mode (DM) noise. Unlike studies that rely mainly on simulation or analytical modeling, this research emphasizes precise measurement techniques to capture both CM and DM emissions over the 150 kHz–30 MHz range, following EN55022 requirements. The effects of duty cycle and MOSFET switching characteristics on EMI levels are systematically examined. Results show that DM emissions dominate over CM across the measured spectrum, with certain configurations exceeding EN55022 Class A limits at low frequencies. The findings highlight the critical role of component selection and operating parameters in achieving EMC compliance, and provide practical insights for optimizing chopper design to mitigate conducted emissions.

Keywords: Static Converters, Chopper Series, Conducted EMI, Measurements, Common Mode, Differential Mode, EN55022 Compliance, Experimental Measurements

Pages: 168-180