Arcing-fault models for low-voltage power systems

An arcing fault is a dangerous form of short circuit that may have a low current magnitude. In the case of such faults, the magnitude of the current is limited by the resistance of the arc and may also be limited by the impedance of a ground path. This lower level fault current is often insufficient to immediately trip overcurrent devices, resulting in the escalation of the arcing fault, increased system damage, tremendous release of energy, and threat to human life. Despite modern advances in system protection, people are critically injured or killed each year when they are in the vicinity of an arcing fault that is either accidentally physically initiated or initiated through a glow-to-arc transition. The initial phase of an ongoing arcing-fault research project was to review the pioneering work, dating back to the 1920s. The historical evolution of arc modeling for low-voltage systems and a summary of the electrical aspects and the physics involved in arcing faults were reviewed in a companion paper (1999). After a comprehensive literature search was completed, today's better analytical tools facilitated the development of new arc models with current-dependent arc voltages. A current-dependent arc voltage better represents the arcing phenomenon than the assumed arc voltage associated with previous instantaneous arc models.