Impact evaluation of series dc arc faults in dc microgrids

This paper evaluates possible impacts of series dc arc faults to dc microgrids. Series dc arc can happen at various locations of a dc microgrid and is associated with high impedance and low fault current level, which adds difficulty to detection and protection. This paper firstly presents dc arc fault modeling of both dc component and high frequency noise component. With the dc arc model, the impact of dc arc faults at various locations of a dc microgrid are then studied. Two different controllers are adopted to study the interaction between dc arc faults and microgrid controllers. It is found that current and voltage control strategies can have adverse impact to dc arc faults and dc arc faults at certain locations can be very difficult to detect with existing dc microgrid protection strategies. Additional dc arc fault detectors are of necessity to improve the overall safety of the microgrid.