Setting Optimization of Distribution Network Current Protection Based on Constrained Multi-Objectives Backbone Particle Swarm Optimization

With the increase in residential electricity consumption, the number of branch lines connected to the 10 kV main line and the load all increase. When the main line is segmented into several shorter lines, the current protections of these lines are difficult to coordinate with each other. This condition may cause the number of protection mal-operation increases, the power outage scope expands, and the reliability of the power supply decreases. Therefore, this paper studies the setting optimization method of distribution network current protections. First, a mathematical model of protection setting optimization is established with three objective functions keeping the fault clearing time minimal, the protection sensitivity highest, and the outage load minimal. Some constraints are considered, such as the cooperation between the protections of the adjacent lines. Second, the multi-objective backbone particle swarm optimization algorithm is used. The problems of the traditional particle swarm optimization algorithm that lacks population diversity and easily falls into local optimization are solved by adopting the time-varying variation and linear decreasing dynamic allocation strategy. Finally, the K-means clustering algorithm is used to get the most representative optimal solution providing a variety of feasible solutions for the practical application. This paper takes a 10 kV line as an example to test the setting optimization method and compares the optimized settings with the traditional ones. The results show that the setting optimization method based on the constrained multi-objective backbone particle swarm can effectively reduce the protection mal-operations and improve the overall performance of distribution network protections. (c) 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.