Mitigating Dynamic Load-Altering Attacks on Grid Frequency with the Proportional–Integral Control Strategy

Grid frequency is a critical factor for the stability of a power system. However, with the penetration of massive dynamic load requirements and information and communication infrastructure, grid frequency is vulnerable to cyberattacks on the load side. In this paper, we model dynamic load-altering attacks (LAAs) on grid frequency and propose a control-based mitigation strategy. First, the dynamic grid-frequency model for frequency-sensitive loads is constructed. Then, the vulnerability of grid frequency to dynamic LAAs is analyzed using eigenvalue sensitivity analysis. To design the mitigation strategy, a stability condition with the first-order dynamic model is derived. Further, a second-order dynamic model is constructed to illustrate the joint impact of dynamic LAAs and the control strategy on eigenvalues, thereby revealing insights into mitigating factors for maintaining grid frequency stability. Finally, we conduct extensive simulations to evaluate the vulnerability of grid frequency under dynamic LAAs and to validate the effectiveness of the mitigation strategy.