Simplified Test Method for DC Charging Communication Immunity to Switching Noise considering Cable Crosstalk

The Power Line Communication (PLC) is used in combination with the Control Pilot (CP) as a method of wired communication between charging stations and Electric Vehicles (EV). Its susceptibility to conducted interference has been shown in previous studies, due to the installation of unscreened signal cables in the same harness as the charging power cables, which carry RF noise originating from the power electronic components of the EV and the station. Although it is well-known that RF coupling of these cables is the dominant noise source on the communication signals, the amount of coupling has yet to be quantified. Considering also that charging stations with different power ratings exist and, consecutively, cables with various lengths and cross-sections are used, a study on the amount of coupling between these two circuits is needed. This paper presents crosstalk measurements of typical charging harnesses, which are also modelled analytically. The final aim is to present a new simplified test method for evaluating the conducted immunity of the on-board communication system, without the need of using any bulky and expensive high-voltage charging cables during the test. Compared to previous presented methods, all the resultant coupling and RF noise of the charging cables are modelled analytically through a novel RF test pulse equation, which is experimentally verified on a prototype vehicle setup.