Novel Pre-diagnosis Strategies for Medium-Low Voltage Arc Flash

With the development of distribution networks in modern power system, the high-power density featured electrical equipment has become more concentrating in medium-low voltage level, which may lead serious safety risks such as serious arc faults or arc flash incidents. To better protect personnel and equipment from dangers, a fast and reliable arc detecting and locating method is thus essentially to be developed. However, due to the issues such as low sensitivity, delayed detection, complex structure, susceptible to interference by other sources, the application of traditional approaches, especially in weak system source and high arcing resistance featured medium-low voltage arc flash, are severely restricted. To avoid those limitation, a spatial magnetic field analysis based hybrid preemptive detection method of arc flash is fully investigated in the work. With the categorizing analysis of geometric configuration, mathematical modeling incorporated MHD approach is developed, which can be effective fast identification of vertical structure and parallel structure of the arc due to the insulation breakage or aging. With a series actual cases based simulations, the transient dynamics of arcing current, and the relationship among arc fault location, discharge types and magnetic field is derived, which offered valuable information for medium-low arc mitigation and hazard prevention.