A systematic debugging methodology for identifying electric vehicle level EMC issues

Electric two and three-wheelers present unique challenges in electromagnetic compatibility testing due to compact packaging, high-frequency switching, and low shielding practices. This paper presents a systematic debugging methodology for identifying and mitigating radiated emission and radiated immunity issues in these EV platforms. A comprehensive approach is outlined, covering radiated emission measurement, Bulk Current Injection based immunity simulation, and near-field probing techniques. For RI evaluation, BCI testing in the 20 MHz to 400 MHz range is used to simulate radiated threats on the vehicle's power and signal harnesses. For RE diagnosis, conducted emission measurements on vehicle harnesses are performed using current probes to capture high-frequency currents. Additionally, near-field electric probes are used at the component to identify dominant noise sources such as DC-DC converters, Motor control unit, and improperly grounded shielding. Case studies on 2W and 3W EVs highlight common failure modes and demonstrate successful mitigation strategies, including filtering, grounding improvements, and layout changes. This practical diagnostic workflow provides an efficient toolkit for EMC engineers to accelerate compliance readiness, reduce test iterations, and enhance system-level EMC performance for small-format electric vehicles.