DoS攻击下基于弹性自触发一致性的多VSGs孤岛微电网功率分配与调频控制OA

The distributed secondary control of multiple virtual synchronous generators(VSGs)in the island microgrid can effectively achieve frequency restoration and reasonable power distribution.However,the distributed control relies on remote information exchange through sparse network,and this communication process is vulnerable to network attacks,which degrade control performance.Among these attacks,denial of service(DoS)attack can block the transmission of secondary signals,which will lead to control errors and affect the stability of the system. Considering the influence of DoS attack,a power distribution and frequency modulation control for multiple VSGs in isolated microgrid based on resilient self-triggered consistency is proposed to solve this problem.Firstly,the output frequency of inverters controlled by VSG is analyzed,and the global DoS attack and local DoS attack are modeled,with such attacks constrained by attack times and attack duration.Then,the resilient controller based on self-triggered consistency algorithm is designed for these two attack types.The DoS attack is considered in the secondary control,so as to improve the resistance to DoS attack.The self-triggered mechanism is introduced to reduce the calculation and communication requirements,and the trigger function is optimized to further reduce the trigger times and calculation cost while ensuring immediate trigger after disturbance.Finally,an islanded microgrid simulation model with four VSGs running in parallel is built to verify the effectiveness of the proposed method.The results show that the control method can ensure the frequency to return to the rated value and realize accurate power distribution under DoS attack,and simultaneously reduces the calculation and communication burden. According to the simulation analysis,the resilient control proposed in this paper can improve the system's ability to resist network attacks by modifying the local clock and power distribution control variables.The self-triggered mechanism with optimized trigger conditions can reduce communication frequency and the number of trigger condition calculations. The following conclusions can be drawn from the analysis:(1)The resilient secondary control can ensure that the system has good robustness under DoS attack,including the global DoS attack that blocks all communication channels and the local DoS attack that affects each channel independently.When the system is attacked by DoS,the control variables are reset to zero,and the local clock is modified to resist the attack.(2)The self-triggered mechanism is used in the signal communication between VSGs,and the next trigger time is calculated only when the local clock decays to zero.This avoids continuous monitoring of trigger conditions and can reduce communication pressure and computation burden.(3)The trigger condition is optimized and the counting variable is introduced to gradually increase the trigger interval when the system enters the steady state,which can effectively avoid the redundant trigger of controllers and reduce the trigger times and calculation cost.After modifying the trigger condition,the communication times under global DoS attack and local DoS attack decreased by 85.8％and 91.3％respectively.(4)Simulation and hardware-in-the-loop experiments show that the proposed control strategy can achieve zero-error frequency regulation and accurate active power distribution.It reduces the link communication and calculation burden,and improves the resistance of VSGs to DoS attack.