The relay protection system in intelligent substations ensures the safety and stable operation of power grids. While redundancy configurations enhance reliability, excessive redundancy compromises economic efficiency. The reasonable redundancy of the relay protection system in the station needs to be considered. In this paper, a multiobjective optimization configuration model is proposed for the intelligent substation relay system considering both reliability and economy, where Markov state space is adopted to determine the reliability and the impact of economic factors such as equipment costs, operation and maintenance costs, and fault losses. In addition, the coupling relationship between reliability and economic factors are used. Then, the entropy weight method is adopted to transform the multiobjective optimization problem into a single objective one. An improved particle swarm optimization algorithm is designed to achieve the optimal configuration of the intelligent substation relay protection system. The proposed optimization configuration method is validated on an actual substation, and the benefits of the substation relay protection system under different redundant configurations are analyzed. The results indicate that the configuration should avoid no redundancy or excessive redundancy. This work provides a theoretical basis for relay protection configuration schemes of the intelligent substation in the future.
Wang et al. (Thu,) studied this question.