Fault-Tolerant Placement of Phasor Measurement Units and Communication Infrastructure in SDN-Enabled Wide-Area Monitoring Systems

Software-defined networking (SDN) separates the control plane from the data plane, features flexible configuration and dynamic programmability, and can enhance the survivability of networks during faults. SDN has been widely applied in wide-area monitoring systems (WAMSs) to enhance their fault defense capabilities. This study investigated the fault-tolerant placement problem of phasor measurement units (PMUs) and communication infrastructure of SDN-enabled WAMSs. First, a hidden Markov model was established to describe the recovery process of observable states of power nodes when the failures of power lines and communication networks occur. Based on the hidden Markov model, the availability of synchrophasors of the power node was calculated. Second, a mathematical model for the simultaneously optimal placement of the PMUs and SDN infrastructure was formulated to minimize the construction cost of the WAMS. The mathematical model was calculated using a particle swarm optimization (PSO) algorithm. Finally, simulation experiments were performed on an IEEE 30-bus system and an IEEE 118-bus system to verify the effectiveness of the proposed method. Experimental results indicate that the proposed method can effectively improve the accuracy of the state estimation, which enhances the ability of WAMSs to mitigate failure risks.