Application of ${p}$-Cycle Protection for the Substation Communication Network Under SRLG Constraints

In order to improve the security and stability of the intelligent substation communication networks, a novel shared risk link group (SRLG) weighted p-cycle algorithm (SWCA) is proposed by considering the diversity of different substation links and the associated fiber core. The proposed approach is dedicated to solve the problems of multiple failures by sharing risk analysis. Hybrid integer linear programming and heuristic algorithm implementation are presented to reduce the complexity of optimizing bandwidth allocation under SRLG constraints. The performance of bandwidth utilization, service reject rate, and protection resource redundancy is investigated under the dynamic traffic environment, and the optimum SRLG number is discussed. The experimental results from two demonstration networks with randomly set SRLGs show that SWCA can reserve more bandwidths and, therefore, more service requests can be served at the expense of protection redundancy. Completely separated SRLG protection will decrease simultaneous failure probability of the working path and protection path and, thus, improve the survivability of the substation communication network compared with the classical capacitated iterative design algorithm-grow and shortest path pair protection method. Meanwhile, the approach can restore multiple failures within intelligent substation communication networks, and can therefore enhance the survivability of the electric power communication network.