DC Arc Flash: Expanded Incident Energy Equation for 125 V Substation Battery Backup Systems

Arc-flash is one of two hazards primarily associated with electrical systems. Due to its prevalence, the majority of arc-flash research has been dedicated to alternating-current (ac) electrical systems. However, direct-current (dc) electrical systems are becoming increasingly common, such as energy storage systems, solar photovoltaic panels, and dc microgrids. Thus, more research is needed to address the arc-flash hazards posed by dc electrical systems. Current dc arc-flash models are theoretical and lack empirical data compared with ac arc-flash models. This article presents models developed through empirical testing utilizing low-voltage (LV) station batteries. Furthermore, this article investigates possible interactions between dc arc-flash within LV battery systems and atmospheric conditions, such as temperature and relative humidity. In the end, this article provides information regarding the implementation of these models within American Electric Power's (AEP's) safety practices regarding batteries and dc panelboards.