Research On Resilient Distributed Control Of Islanded Microgrids Under False Data Injection Attacks

Renewable energy such as solar energy and wind energy are developing rapidly like mushrooms after rain,but due to their intermittency and uncertainty,they are difficult to be put into large-scale centralized use.Most renewable energy exist in a distributed form.Microgrids are an extremely effective way to integrate distributed generation(DG),and the secondary control of microgrids is currently a hot topic of research in this field.Before exploring secondary control,discuss the problem of excessive circulation caused by a type of output impedance mismatch firstly;For secondary control of microgrids,distributed control is commonly used for regulation.With the increase in the number of DGs in the microgrid,the computational load also increases.At the same time,distributed control requires neighboring DGs to transmit information to each other when completing tasks,and the transmission process is also susceptible to malicious attacks,as well as being limited by network transmission resources.False Data Injection(FDI)attack is a highly covert and destructive attack that disrupts the control target by destroying the real data of the control system.Therefore,this project focuses on the problem of excessive circulation caused by output impedance differences in microgrids and the FDI attack faced by distributed secondary control.It studies how to design distributed control strategies to reduce circulation and alleviate or eliminate the threat of FDI attacks to microgrid systems.The main tasks completed are as follows:(1)For the problem of excessive circulating current caused by output impedance mismatch of islanded AC microgrid,a voltage consistency H_∞control strategy is proposed.Firstly,consider the output current as a disturbance and establish an equivalent circuit mathematical model for multiple DGs.Then,by compensating for the error between the reference voltage value and the actual output voltage value,the control signal is applied to the voltage outer loop controller to achieve superposition with the given voltage signal.Finally,synchronize the output voltages of each DG to effectively improve the circulating current suppression ability and power sharing accuracy based on the droop characteristics.(2)For the problem of FDI attack on the sensor side and the actuator side of the disturbed DG,a distributed robust resilient adaptive control strategy is proposed.Firstly,establish a DG mathematical model under FDI attacks.Then,a state observer is designed for each DG to predict the expected normal behavior of the DG when it is not damaged,and the malicious attack is compensated by the error value between the DG’s state observation value and the actual value.Finally,while attenuating dynamic interference and ensuring robust gain performance,ensuring the stability of the microgrid in the presence of FDI attacks.(3)For the problem of FDI attacks on the sensor side and the actuator side of the DG,an observer-based resilient integrated distributed control strategy under Event Triggering Mechanism(ETM)is proposed.Firstly,model the microgrid that has been attacked by FDI.Then,a normalized active and reactive power observer is designed to exchange information by using observed power values,and local state variables are used to estimate and compensate for potential attacks on each DG.Finally,it makes frequency and bus voltage as local private variables,which greatly reduces the communication burden and effectively resists the adverse effects of FDI attacks.