Relay protection and automation devices selectivity assessment procedure with consideration for labor protection and 6(10) kV cables insulation durability improvement

Nonselectivity and reserve areas of outgoing cables, distribution points, and transformer substations are determined in this article, as exemplified by city 6(10) kV cable network schemes with various short-circuit currents. An algorithm of fault finding which reduces personnel residence time in electrically hazardous areas is introduced. Temperature conditions of insulation are assessed using a model designed in ANSYS according to the relay protection and automation setting selection procedure.