Reflections on the Upgrading of Distribution Network Induced by a Hierarchical Tripping Accident

With the development of cities, cable equipment has been extensively utilized in distribution networks, and the compensation capacity of arc suppression coils in 10 kV distribution networks has gradually become insufficient to meet the compensation demands. Neutral grounding through the low resistor is a common solution to solve the problem in some regions. Along with the change in neutral grounding, the corresponding relay protection should also be adjusted accordingly. However, due to the complexity of the distribution network structure, a single adjustment in protection often fails to fully satisfy the coordination requirements between superior and subordinate protections. This paper begins with a typical hierarchical tripping accident, analyzes the causes of such accidents under this distribution network, and proposes corresponding measures to prevent hierarchical tripping accidents and to optimize this network structure. It offers feasible suggestions for the construction of a new type of power system, thereby effectively enhancing the reliability of power supply in distribution networks.