Determination of Induced Antenna Voltage for DC–AC Converter on Electric Vehicles at High Frequencies

Development in complex electrification systems could potentially result in different EMI levels between component and vehicle assessments. This study investigates the determination of induced voltages at antennas during $\mathrm{DC}-\mathrm{AC}$ conversion in a bidirectional on-board charger on an electric vehicles (EV) in the FM radio band. First, correlations between conducted currents on power cables and antenna voltages in the vehicle were investigated experimentally. Subsequently, a system-level configuration was developed to replicate equivalent currents in the vehicle. Additionally, coupling coefficients between power cables and antennas in the vehicle were measured using two current probes. The results demonstrate similar tendencies of frequency-dependent conducted currents on AC and DC charging cables to inlets and antenna voltages in the vehicle were observed. A common mode current on DC inlet cable in the system-level configuration was almost identical to that in the vehicle, with a difference of 3 dB around frequencies with peak values. Finally, an estimated antenna voltage in the vehicle, derived from common mode currents in the vehicle using coupling coefficients, shows a7 dB difference at the frequency of maximum value compared to the actual antenna voltage. Further exploration of antenna coupling coefficients is recommended for effective EMI noise mitigation in the early design phase.