Optimal communication-aided protection of meshed smart grids considering stability constraints of distributed generations incorporating optimal selection of relay characteristics

Abstract

The optimized protective systems for smart grids and microgrids have received much attention in recent years. However, besides other selectivity constraints, less attention has been paid to synchronous generators’ stability concerns. The stability challenges are intensified in meshed grids compared to radial configurations. The literature review shows that a knowledge gap exists in introducing a communication-aided protective scheme for meshed smart grids, considering the stability constraints. This study tries to fill such a research gap by proposing an optimal protection system using the communication links between directional overcurrent relays on both sides of protection zones/distribution lines. Assigning the optimum standard characteristics to protective relays is another contribution. The introduced study is applied to the distribution portion of the IEEE 30-bus test system. The proposed method is implemented in DIgSILENT and MATLAB to perform the power system simulations and solve the optimization problem. The comparative test results infer that the proposed communication-aided scheme results in a 49.57% improvement in speed of the protection system, while there is no stability constraint violation compared to conventional communication-free schemes. Test results highlight the advantages of this research to meet the stability constraints of distributed generations and selectivity constraints simultaneously.