Adaptive Observer-Based Resilient Control Strategy for Wind Turbines Against Time-Delay Attacks on Rotor Speed Sensor Measurement

With the increasing proportion of wind power generation in the power system, the vulnerabilities of the cyber links of wind turbines (WTs) are gradually exposed. The time-delay attack (TDA) by flooding the communication link between the rotor speed sensor and the controller may reduce the wind generation or overload the WT drive train. This paper attempts to develop an adaptive observer-based resilient control method for WT to defend against TDA. An attack model is established to characterize the behavior which delays the transfer of the rotor speed information to the WT controller, and the real-time adaptive state observers are designed to offset the delayed sensor information caused by the TDA. An adaptive resilient torque control is developed to ensure the optimal rotor speed output, and the attack resilience level of the WT considering the TDA is evaluated. Extensive studies on the 1.5 MW WT illustrate that the proposed resilient control scheme has the ability to mitigate the effect of TDA and guarantee the output performance of the WT system.