Safety Design of Electric Vehicle Charging Equipment

Besides cost issue, the charging infrastructures popularization and charging safety assurance are two major concerns for promoting electric vehicles (EVs). Several pilot-run programs, such as in the U.S., Europe, Japan, China, and Taiwan as well, enforce the safety compliance of EVs and infrastructures as an implementation policy. To be part of the players, it is essential to have the comprehensive understanding of the standard differences among IEC, SAE/UL, GB and JEVS. The way to compile the issued standards in different regions, however, is time consuming and may get limited helpful hints until tried and tested. Based on above-mentioned standards, this study summarized an overview in aspects of construction, function, performance and safety for charging equipments. To facilitate as a competent safety design, key requirements of electrical safety were presented. These crucial design rules included functional requirements, constructional requirements, personal protection against electric shock, insulation coordination, electromagnetic compatibility and charging control. The rationale and compliance requirements were highlighted to assist as design guidelines. In addition, learning from the past is always a good approach to build confidence to comply with the safety requirements. Based on the standards—follow most IEC and some SAE/UL—for pilot-run project in Taiwan, a case study of an AC charging stand provided the safety faults encountered and solutions in designing a new product that can meet safety requirements effectively. With these design guidelines and the case study, this paper provided a solid basis of safety design for electric vehicle charging equipments.