RF coupling behaviour between the high and low voltage levels in automotive power networks

By using highly efficient electrical drive systems in modern vehicles, different voltage levels for the drive system and other electronic devices are applied. In the most automotive HV components which contain sensors or contactors, e.g. in a HV-battery device, both voltage levels are interconnected and concentrated in a small space. Regarding Electromagnetic Compatibility (EMC) aspects, the decoupling of the HV and the LV system is very important for a safe and reliable function of the component itself and the whole overall vehicle system. In this contribution the measurement of the coupling behavior between the HV and the LV part of a HV battery system and of a complete vehicle system is described. The measurement is done by feeding RF power into the HV connection in common respectively differential mode and measuring the injected power at LV wiring harnesses or interfaces of the component.