| In recent years,the interconnected energy system(IES)has often been suffered from cooperative cyber-physical attacks(CCPAs),which threaten the security and economy of the system.Therefore,it is of great importance to consider the impact of CCPAs on the optimization scheduling of IES.For the gas-electricity IES,the optimal attack strategy,which includes the coordination of load redistribution attack and physical attack destroying the energy supply network,is studied from the attacker’s perspective in the paper.And the optimal defense strategy considering system reserve capacity and alternative load is studied from the defenders’ perspective.The main research contents include:(1)Research on the optimal scheduling strategy of gas-electricity IES without attack.The paper uses the grid direct-current(DC)flow equation and the natural gas network Weymouth flow equation to calculate the system steady-state flow.Considered the output constraints of various equipment,the optimal scheduling model of gas-electricity IES is established which the objective is to minimize the total cost including the coal expenses,the natural gas expenses and the load shedding cost.The model is solved by Yalmip.The solution provides a reference when evaluating the attack-defensive policy in later chapters.(2)Research on the gas-electricity IES attack strategy of CCPAs from the perspective of attackers.Firstly,from the perspective of attackers,the attack difficulty function and the attack effect function of CCPAs are proposed.Based on these two functions,a single-objective bi-level attack model without the attacking difficulty function and a multi-objective bi-level attack model are established.Secondly,based on the improved particle swarm optimization(PSO),the optimal solution of the single-objective model and the optimal Pareto set of the multi-objective model are obtained separately.Finally,the optimization results of these two models are analyzed and mutually confirmed so that the optimal attack strategy can be obtained.The optimal attack strategy makes the gas-electricity IES in the worst running status and bears the maximum cost loss.(3)Research on the optimal scheduling strategy of gas-electricity IES with system reserve capacity and alternative load from the defenders’ perspective.The reserve capacity and alternative load,which are used as defense measures,are incorporated into the optimal scheduling model.The optimal defense strategy model with the total cost of the system spinning operating expenses,reserve expenses,and alternative load expenses is established and solved by Yalmip.The optimal defense strategy indicates that the reasonable arrangement of the reserve capacity is more conducive to the interaction with alternative load to achieve better defense effects and enhance the economics of the system.The paper uses the improved IEEE 14-node system and the improved natural gas 9-node system as the platform to optimize scheduling.The scheduling results verify the effectiveness of the model and strategy. |
