Analysis and Application of SDN Based Dynamic Optimal Route Strategy for Cyber Layer in Cascading Failures of Cyber-Physical Power System; [基于SDN的动态优化路由策略在信息物理融合电力系统连锁故障中的研究与应用]

Delay in cyber layer plays a critical role in cascading failure propagation in cyber-physical power system (CPPS). To mitigate cascading failure risk in CPPS, it is imperative to focus on the strategy to decrease the delay and analyze its effects. This paper firstly describes cyber layer structure of CPPS in soft defined network (SDN) perspective, and proposes a dynamic optimal route strategy for the cyber layer based on SDN to decrease the delay and congestion. Then, data transmission delay and cyber node data congestion situations under various cases are compared. The cases include small-world cyber layer topology and scale-free cyber layer topology, also the static data route strategy and SDN based dynamic data route strategy. At last, going back to the cascading failures in CPPS, the cascading failures for various initial failures and data route strategies are simulated and compared. For both small-world and scale-free cyber layer topologies, the dynamic data route strategy based on SDN mitigates data congestion for nodes and decreases both the longest delay and mean delay for data transmission. Simulation of cascading failures demonstrates that the dynamic data route strategy improves security control accuracy and mitigates cascading failure vulnerability in CPPS. © 2018, Power System Technology Press. All right reserved.