Exploration of the Impact of High Voltage Ground Fault in an Electric Vehicle Connected to Earthing Systems Worldwide

Vehicle safety is of paramount importance when it comes to plugging the vehicle into the electric utility grid. The impact of high voltage ground fault has been neglected or, if not, addressed by guidelines extracted from general practices, written in international standards. The agile accretion in Electric Vehicle (EV) development deems an exhaustive study on safety risks pertaining to fault occurrence. While vehicle electrification offers a vital solution to oil scarcity, it is essential that the fast development of the number of electric vehicles on the road does not compromise safety. Meanwhile, the link between technology and demands of society must be governed by vehicle safety. In this paper, a comprehensive study on high voltage (HV) fault conditions occurring in an EV will be conducted. In the next decade, EVs are expected to be prevalent worldwide. Ground fault characteristics are significantly dependent on the earthing system. The state of neutral, supplied by the utility company, in different grounding systems differ from country to country. Moreover, one country could have multiple grounding systems. As will be demonstrated in this paper, each grounding system has a unique implementation. An analytical model describing the theory of the impact of an HV ground fault on a vehicle connected to the TT and TN earthing systems will be developed. Lastly, Safety risks are quantified and assessed for the operation of non-isolated chargers.