Due to the increasing adoption of smart sensing and Internet of things (IoT) devices, wind energy system (WES) becomes more vulnerable to cyber and physical attacks. Therefore, designing a secure and resilient WES is critical. This paper first proposes a system-of-systems (SoS) framework for the cyber-physical WES. Specifically, on the one hand, we adopt a game-theoretic model to capture the interactions between the WES system defender and the adversary at the cyber layer. The outcome of this cyber defense game is reflected by control-aware Nash equilibria. On the other hand, we devise a cyber-aware robust and resilient switching controller based on a Markov jump linear system model for the physical WES. The performances of the WES cyber and physical layers are interdependent due to their natural couplings. We further investigate the SoS equilibrium of the integrated WES, which considers the system security, robustness, and resilience holistically. Finally, we use case studies to corroborate the developed cross-layer design principles for the cyber-physical WES. Note to Practitioners—Cybersecurity becomes a critical concern of wind energy system (WES) operators as an increasing amount of IoT devices are adopted for WES’s communication, monitoring, and operation support purposes. This cyber-physical integration in WES creates a much broader attack surface because adversaries can compromise the physical WES by attacking its dependent cyberspace. To mitigate the impact of attacks, the operator should not only design intelligent control strategies for WES but also strategically secure the WES’s cyber layer. These two goals are naturally coupled together. On the one hand, the WES operates under different compromised conditions depending on the attack actions at the cyber layer. Thus, the control design needs to be adversary-aware by taking the real-time cyber state into account. On the other hand, the adversary’s cyberattack strategy is influenced by the induced performance degradation of WES. Hence, the corresponding attack measures and countermeasures, in turn, should be physically control-aware. This paper establishes a holistic mathematical framework to simultaneously address these two challenging objectives. The obtained solution provides guidelines for the WES operator on the optimal security resource investment in defending against cyberattacks and the robust switching control design to mitigate the impacts of attacks further. This methodology creates a defense-in-depth paradigm for the WES operators to maintain the energy system efficiency in the adversarial environment. This cross-layer design approach is also efficient and user-friendly for online implementation with the developed iterative algorithm. The simulated-based case studies in this paper show the effectiveness of the proposed approach. However, a more thorough validation of the method in practice is necessary before its integration with the production standard.

中文翻译：

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战略网络防御和网络物理风能系统鲁棒切换控制的跨层设计方法


由于智能传感和物联网 (IoT) 设备的日益普及，风能系统 (WES) 变得更容易受到网络和物理攻击。因此，设计一个安全且有弹性的 WES 至关重要。本文首先提出了网络物理 WES 的系统系统（SoS）框架。具体来说，一方面，我们采用博弈论模型来捕获WES系统防御者与网络层对手之间的交互。这种网络防御博弈的结果通过控制感知纳什均衡来反映。另一方面，我们基于物理 WES 的马尔可夫跳跃线性系统模型设计了一种网络感知的稳健且有弹性的开关控制器。 WES 网络层和物理层的性能由于其自然耦合而相互依赖。我们进一步研究了集成 WES 的 SoS 平衡，它从整体上考虑了系统的安全性、鲁棒性和弹性。最后，我们使用案例研究来证实为网络物理 WES 开发的跨层设计原则。从业者须知——随着越来越多的物联网设备被用于 WES 的通信、监控和运营支持目的，网络安全已成为风能系统 (WES) 运营商的一个关键关注点。 WES 中的这种网络物理集成创建了更广泛的攻击面，因为对手可以通过攻击其依赖的网络空间来破坏物理 WES。为了减轻攻击的影响，运营商不仅应该为WES设计智能控制策略，还应该从战略上保护WES的网络层。这两个目标自然地结合在一起。 一方面，WES 根据网络层的攻击行为在不同的受损条件下运行。因此，控制设计需要考虑实时网络状态来了解对手。另一方面，对手的网络攻击策略受到 WES 引起的性能下降的影响。因此，相应的攻击措施和对策也应该是物理控制感知的。本文建立了一个整体数学框架来同时解决这两个具有挑战性的目标。获得的解决方案为WES运营商提供了防御网络攻击的最佳安全资源投资和稳健的切换控制设计以进一步减轻攻击影响的指南。该方法为 WES​​ 运营商创建了一个纵深防御范式，以在对抗环境中保持能源系统效率。这种跨层设计方法对于使用开发的迭代算法进行在线实现也是高效且用户友好的。本文基于模拟的案例研究表明了所提出方法的有效性。然而，在与生产标准集成之前，需要在实践中对该方法进行更彻底的验证。