Cascading Failure Models Against The Optimal Strategy Of Power System Attacks

When the power system is exposed to various physical threats such as extreme events,technical failures,and intentional damage,cascading failures can occur,leading to large-scale power outages in the transmission system.Therefore,this thesis considered the power system cascading failures model and the allocation of attack and defense resources to obtain the optimal attack strategy.In this thesis,the cascading failures of power system are studied and the algorithm of power system cascading failures model based on optimal tide analysis method is given.Three attack scenarios are also considered: random target attack,the fixed target attack and dynamic attack,and simulation experiments are conducted.The results show that the fixed target attack is more advantageous than the random attack,and attacking more nodes connected to the branch circuit will make the system collapse faster;multiple attacks are more effective than one attack;in the dynamic attack scenario,the reliability of the power system decreases with the increase of the number of attacks.The previous cascading failures model only considered the case that the attack must be successful,and this thesis further considered the case that the attack is not necessarily successful.By introducing the attack success probability,two strategic attack scenarios are considered: a)no-attack resource scenario.The relationship between defense resources and attack success probability is described using an exponential function,and the optimal attack strategy based on defense resources is analyzed,i.e.,when the attack success probability of each node is greater than or equal to 0.5,the node with the most branches is chosen to attack more effectively,and the defender will allocate more defense resources to such nodes;b)with attack resources scenario.The effect of attack resources and defense resources on the probability of success of an attack is described using the competition function.With appropriate competition strength,the attack success probability decreases as the number of attacks grows,and simulation experiments are conducted.The results show that: a few strong strikes are more effective than more weak strikes when limited attack resources are allocated;strategic attacks are more advantageous;and the reliability of the system does not decrease with the increase of the number of attacks with limited attack resources.