蓄意流量攻击下基于确定网络演算的互联电网自适应负荷频率控制策略

蓄意流量攻击通过抢占有限的网络带宽降低正常数据流的时效性。对于网络化负荷频率控制(load frequency control, LFC)，流量攻击将造成稳定裕度下降、频率偏差幅度上升甚至越限事故。现有控制方案一般采用单一且固定的控制器保证最大攻击强度下的渐进稳定性，存在设计约束多、保守性大的缺点。因此提出了一种跟随攻击强度自适应调整控制器增益的LFC策略。首先，基于确定性网络演算，得到了无攻击场景下数据流传输延时上边界，并预设了一系列表征不同攻击强度的传输延时范围。其次，通过构造Lyapunov泛函，推导了针对每个攻击强度的控制器设计准则。最后，基于切换控制理论，确定了所提自适应方案所能容忍的最大攻击强度变化频率。仿真表明，与现有控制方案相比，所提方法的频率偏差幅度可下降12.60%，区域控制误差的绝对值误差积分可下降10.85%。

Deterministic networked calculus-based adaptive load frequency control in interconnected power systems considering malicious traffic attacks

Malicious traffic attacks can reduce the timeliness of normal data flows by seizing the limited bandwidth. For networked load frequency control (LFC), traffic attacks will cause stability margin decline, frequency deviation rise or even over-limitation accidents. In most existing control schemes, a single and fixed controller is used to ensure asymptotic stability under maximum attack intensity. This has disadvantages such as many design constraints and great conservatism. A novel LFC strategy is proposed to adaptively adjust the controller gain according to attack intensity. First, based on deterministic network calculus, the upper data transmission delay bound in a no-attack scenario is obtained. Then a series of transmission delay ranges representing different attack intensities are preset. Second, by constructing a Lyapunov function, controller design criteria for each attack intensity are derived. Finally, in a switched control framework, the maximum attack switching frequency that the proposed adaptive scheme can tolerate is derived. Simulation results show that compared with the existing schemes, the frequency deviation amplitude with the proposed method can be reduced by 12.60%, and the integral of the absolute error of the area control error can be decreased by 10.85%.