Influences of Ground Connection and Cable Length on the EMC behavior of Electric Vehicles during Conductive Charging Operations

In this paper, the conducted electromagnetic compatibility (EMC), in particular the emission of electric vehicles (EVs) during conductive charging, is investigated. For this purpose, a second reference plane is used in the laboratory setup of a modified CISPR 25 setup to replicate the vehicle body. This introduces a variable stray capacitance regarding the reference potential. In addition, the length of the charging cable and the connection of both ground planes are systematically varied and their effects on the interference disturbance level are investigated. The analysis is performed with measurements of the disturbance voltages, disturbance currents, impedance, and circuit simulations. In the second step, the influences of the ground connection are also examined for the first time on an electric vehicle. Comparing both setups yields a first estimation of how well a component test can emulate EMC influences during conductive charging.