高级量测体系(Advanced Metering Infrastructure， AMI)是新型电力系统的关键组成部分，异构通信网络和智能终端的广泛应用导致其易受到网络攻击威胁。本文研究分布式拒绝服务(Distributed Denial-of-Service， DDoS)攻击下AMI网络的动态建模与最优防御策略。首先，分析DDoS攻击在AMI网络中的传播路径，并结合复杂网络理论与SEIR传染病模型，建立了一个刻画AMI网络中节点遭受DDoS攻击后的状态演化模型，分析DDoS攻击在AMI网络中的传播机理和攻击容忍水平；然后，以最小化防御损失和成本为目标提出了一种在AMI网络中灵活优化部署防御资源的防御策略。最后，在两种不同的AMI网络结构下进行了大量的数值仿真验证了所提策略的有效性。

Advanced metering infrastructure is a key component of the new power system. The wide application of heterogeneous communication networks and intelligent terminals makes it vulnerable to cyber-attacks. This paper studies the dynamic modeling and optimal defending strategy of AMI network under distributed denial-of-service attacks. Firstly, the propagation path of DDoS attack in AMI network is analyzed. Combined with complex network theory and SEIR epidemic model, a state evolution model is established to describe the state evolution of nodes in AMI network after DDoS attack. The propagation mechanism and attack tolerance level of DDoS attack in AMI network are analyzed. Then, a defending strategy for flexibly optimizing the deployment of defense resources in AMI networks is proposed with the goal of minimizing defense losses and costs. Finally, the effectiveness of the proposed strategy is verified by a large number of numerical simulations under two different AMI network structures.