Analysis of Relay Protection for Distribution Networks in Small Resistance Grounded Substations

This study briefly introduces the characteristics of small resistance grounded systems. Two retrofitted 110 kV substations in Xuzhou are selected as case studies. The protection range and tripping logic for their 10 kV distribution network relays are compared. The substation operation and maintenance operators can back-trace fault locations based on protection tripping signals. The results provide practical guidance for rapid fault location in substation of 10 kV distribution networks.