Fault Tolerant/Intrusion Tolerant Cooperative Control For Islanded AC Microgrid System

All walks of life in life are inseparable from the use of electric energy,but with the increasing demand for electric energy,it has brought serious consequences to the atmospheric environment and energy storage.In response to the above problems,scholars from various countries have proposed distributed power generation technologies.These new distributed power generation technologies have the characteristics of decentralized power generation,nearby power transmission,and flexible power supply.The promotion and application of microgrids further expands the advantages of distributed power generation,reduces transmission energy consumption,improves power supply efficiency,and extends the continuous power supply time of the system.Different from the large power grid,the operation mode of the micro grid can be divided into two modes: grid connection and islanding.This article is aimed at the isolated AC microgrid control system with parameter uncertainty.When there is external interference,consider the actuator failure,and when the false data injection network attack occurs on the actuator side,the fault/attack diagnosis of the microgrid control system is studied.Cooperative control problem with robust fault tolerance/intrusion tolerance.The main research contents are as follows:(1)According to the structural topology and control diagram of the AC microgrid control system in island mode,based on Kirchhoff’s voltage and current law and Clark transformation and other circuit laws,derive the state space model of the AC microgrid control system;Considering all possible actuator failures and actuator-side network attacks with false data injection in the system,establish a closed-loop system model integrating faults,attacks and interferences,and propose a robust and reliable faulttolerant/intrusion-tolerant coordination based on dynamic output feedback Control Method.The Lyapunov function is used to deduce the sufficient conditions to ensure that the microgrid control system is gradually stable when the actuator fails and suffers from false data injection network attacks,and the system has good disturbance suppression performance.(2)Based on the actual mathematical model of the island AC microgrid control system,with the idea of active and passive fusion,considering the time-varying fault of the actuator,the failure of the island AC microgrid control system is considered.The design problem of fault-tolerant/attack-intrusion-tolerant cooperative controller is studied.First,according to the closed-loop model of the system,an augmented observer is designed to estimate the status and faults online,and then the time-varying faults of the actuator are compensated through fault adjustment to design robust fault active fault tolerance,and inject false data on the actuator side into the network attack Regarded as a special kind of interference,the output feedback control strategy enables the system to have robust disturbance suppression performance against network attacks.(3)In order to further reduce the impact of false data injection network attacks on the system,the active fault-tolerant/intrusion-tolerant coordinated control method is used for actuator failures and network attacks at the same time.First,the system state and the actuator network attack are expanded into a new state according to the idea of state augmentation,and then the robust state,fault and attack augmented estimation observer is designed to separate the actuator fault and the actuator side network attack Perform online estimation and give feedback compensation;finally,the stability of the microgrid control system is studied through the output feedback control strategy.