Susceptibility of 100Base-T1 Communication Lines to Coupled Fast Switching High-Voltage Pulses

With the electrification of the traction system in current vehicle architectures, operating voltages of up to 850 V are introduced. Alongside with these fast switched voltages comes an increase of electromagnetic interference (EMI) inside the vehicle which may affect other in-vehicle systems. Especially with regard to the immunity of the latest communication and sensor systems, the in-vehicle electromagnetic compatibility (EMC) becomes a challenging aspect. This work focuses on the coupling effects between the high-voltage (HV) system and a 100Base-T1 two-wire Ethernet communication and the impact of pulse disturbances on the communications performance. Therefore, a test setup is presented which approximates the in-vehicle situation. It primarily consists of an electric vehicle traction system, which can be driven in different operating modes. An unshielded twisted pair (UTP) cable, terminated with passive load networks routed in parallel, is used to measure and analyze the coupled disturbance signal at its termination networks. Subsequently, in a second setup, immunity tests on an active communication line are performed in order to determine the impact of the coupled pulse disturbance on the performance of the communication channel.