Research On Distributed Cooperative Control And Energy Management Of Microgrids With Complex Communication Environment

Along with the burgeoning development of power generation techniques by using wind energy,solar energy,biomass energy,etc.,precisely regulating and uniformly managing distributed power supplies in form of microgrids become a significant act to facilitate energy resources transforming into green and low-carbon manners.With characteristics of various types,large amounts,diverse attributes and geographical distribution,how to achieve cooperative control and energy management among multiple distributed power supplies is of great practical importance for the stable operation,high-quality power supply and economic dispatch of microgrids.The theory and method of distributed control and optimization based on communication network provides an ideal solution,and is the key to realize the large-scale promotion and application of microgrids in multiple scenarios.However,in practice,factors such as external disturbance,bandwidth limitation,cyber attacks,privacy leakage,etc.in complex communication environment will invalidate the implementation of dynamic control and optimization decision,and will further affect the reliable and safe operation of the whole microgrid system,even cause system collapse.To deal with above problems,in this paper,taking the microgrids as the research object and with the help of hierarchical control conception as well as multi-agent system cooperative control framework,technical means such as robust anti-interference,event-triggered mechanism,active security defense,differential privacy optimization,etc.,are fully adopted to conduct in-depth research on distributed cooperative control and energy management of smart microgrids which considers various facets such as system modeling,algorithm design,performance analysis,simulation,etc.The explicit research contents are as follows:Distributed robust cooperative control for microgrids resisting unknown disturbance.As for the secondary control problem of AC microgrids with unknown external disturbance,according to the convergence and formation control protocol of multi-agent systems,a distributed robust frequency restoration algorithm and an active power sharing algorithm are proposed respectively,which can offset external disturbance.Both algorithms can achieve the control objectives only by using the information of itself and its neighbors.Based on this,the sufficient conditions for the system to achieve exponential convergence are analyzed via the Lyapunov stability theory,and the qualitative relationship between the convergence rate and the algebraic connectivity and control gain of the communication network is revealed.Besides,simulation examples illustrate the advantages of the proposed algorithms in resisting unknown disturbance,accelerating convergence speed,etc.Distributed robust cooperative control for microgrids considering event-triggered mechanism.As for the secondary control problem of AC microgrids with unknown external disturbance and limited communication bandwidth,based on the static event-triggered mechanism,the distributed finite-time control algorithm and the distributed fixed-time control algorithm are proposed respectively.The algorithms will only carry out corresponding data interaction and input update when the preset event-triggered conditions are satisfied,which can not only effectively save communication cost and control resources,but also realize frequency restoration and proportional sharing of active power in limited and fixed time.Based on this,the sufficient conditions for the system to achieve finite-time and fixed-time convergence are analyzed through the stability principle,and the maximum set time are obtained.Besides,simulation examples illustrate the advantages of the proposed algorithms in reducing the number of communications,resisting unknown disturbance,accelerating convergence speed,etc.Distributed resilient cooperative control strategy involving economic dispatch for microgrids.As for the secondary control problem of multi-bus DC microgrids with limited communication bandwidth and cyber attacks,based on the dynamic event-triggered mechanism and active security defense method,by integrating the voltage regulator with average voltage estimation algorithm and the power regulator with optimal power controller into the secondary control layer,the distributed resilient cooperative control strategy involving economic dispatch is proposed,which can achieve average voltage restoration and optimal power allocation simultaneously with less data interaction and input update.Based on this,via the stability principle,the sufficient conditions between the realization of the control objectives and the feedback gain,the event-triggered coefficients and the attack parameters are revealed,and the convergence results of the distributed average voltage estimation algorithm and the convergence and optimality analysis results of the optimal power controller are given.Besides,simulation examples illustrate the advantages of the proposed strategy in reducing the number of communications,defending cyber attacks,achieving economic dispatch,etc.Differential privacy energy management for microgrids with consensus-based ADMM algorithm.As for the tertiary control problem of microgrids with privacy protection requirements,considering to convert the energy management problem which entails the economic dispatch and demand response into the problem of dynamic social welfare maximization,an energy management scheme with consensus-based ADMM algorithm and differential private protection mechanism,i.e.,distributed differential privacy ADMM algorithm,is proposed,which can not only protect the sensitive information in the process of data interaction,but also find the optimal solution of the problem in a distributed way.Based on this,via strict mathematical proof,the convergence,optimality,accuracy,and privacy of the algorithm are analyzed.Besides,simulation examples illustrate the advantages of the proposed algorithm in application scenarios,privacy requirements,energy management,etc.