The Influence of DC Household Electrical Appliances on Series Arc Fault Characteristics

There are multiple kinds of sources and loads in dc microgrids, leading coupling system noise interferences to series arc fault signals. In order to meet load operation requirements of the proper voltage level and electrical energy form, multiple involved power electronic components would also have a significant influence on series arc fault characteristics. To guarantee the effective arc fault protection, series arc fault experiments and characteristic analysis are important to be conducted in this situation. At first, an experimental setup of a typical dc microgrid is designed with three voltage levels (750V, 400V, 48V) in this paper. Then the series arc fault electrical signals are acquired through three kinds of current sensors with different kinds of single dc household electrical appliance. Arc fault current profile would not show significant variations with some dc household electrical appliances such as a dc induction cooker. Next, the series arc fault current would display different behaviors due to the unique operation characteristic of household electrical appliances, resulting in arc fault detection difficulties. After processing the arc fault current through the time-frequency transformation, distribution patterns of arc fault information are summarized in another domain. Finally, normal operations of household electrical appliances are compared to understand differences between the system transitions and arc faults, which lays the foundation of the accurate arc fault detection.