Increasing electrical safety of a 10/0.38 kV network by clarifying the settings of protection devices in the event of a break in the 10 kV overhead line

A wire break is a common accident in distribution networks operating with an isolated neutral. Failure to shut down such an situation results in the risk of electric shock. For proper operation of protective devices in the event of a wire break, it is necessary to select the correct setting of the information parameter. The negative sequence voltage can serve as such a parameter. This paper presents the results of studies of the influence of different operating modes of a 10/0.38 kV electrical network (both emergency and normal) on changes in the negative sequence voltage. The influence of the fault location and the parameters of the 10/0.38 kV network on the negative sequence voltage was also studied in order to clarify the negative sequence voltage setting for protective devices that respond to a wire break in the 10 kV overhead line. This minimizes false alarms and increases electrical safety in the 10 kV network.