Research on Coordination of Distribution Network Relay Protection and Online Setting Technology Oriented to the FA Process

With the development of smart distribution networks, Feeder Automation (FA) has become a key means to improve power supply reliability. However, the traditional fixed relay protection settings struggle to adapt to the rapid topological changes during the FA process, which can easily lead to protection miscoordination. To address this, this paper proposes a distribution network relay protection coordination and online setting technology oriented towards the FA process. Firstly, the FA process—including fault location, isolation, and restoration—is decomposed into sequential stages to clarify the protection requirements at each stage. Secondly, a closed-loop “perception-decision-execution“ coordination architecture is designed. Based on real-time interaction between the FA master station and protection devices, a dynamic setting model is constructed to achieve adaptive switching of protection settings according to the FA stages. Furthermore, a multi-stage adaptive setting algorithm based on real-time topology and fault current is proposed, solving the problems of logic blocking and smooth transition during setting switching. Simulation tests based on MATLAB/Simulink and Python show that, in a modified IEEE 33-node system, the proposed technology—compared to traditional fixed-setting protection—can increase the correct operation rate of protection during the FA process by 18.7% and reduce the average fault recovery time by 22.4%, effectively enhancing the selectivity, speed, and reliability of protection.