Quantitative Analysis For The Impact Of Cyber System On Microgrid Energy Scheduling Strategy

Microgrid is a kind of cyber-physical system that deeply integrates computing,communication and control technology.It can realize the optimal allocation of power resources by energy scheduling strategy.However,the failure of cyber system will affect the operation effect of scheduling strategy and damage the economy and reliability of microgrid system.In order to fully consider the risk of cyber system failure and improve the reliability of cyber system,this paper is carried out from the aspects of microgrid energy scheduling mechanism,information transmission and conversion mechanism,cyber-physical coupling relationship,impact quantitative indicators,etc.Firstly,according to the key applications of microgrids and their communication performance requirements,a suitable communication method is selected by comparing the performance of current common communication technologies.Then,this paper proposes a microgrid three-layer architecture including physical layer,communication layer and information layer,and introduces various components and their functions of the cyber system and the physical system respectively.Among them,we establishe the photovoltaic,fan and response subject model for distributed components in the physical microgrid system.On this basis,the significance of the proposed impact quantification method is demonstrated by describing the possible cyber system problems in the operation of microgrid.Secondly,aiming at cyber system problems such as information component failure,routing error or termination,channel quality fluctuation and network congestion,information node / branch model,state model,routing model and transmission model are established respectively.Based on the detailed description of three operation processes(information conversion;transmission,routing and forwarding;information fusion and calculation)of data package,a comprehensive simulation of static coupling and dynamic transmission of the system is realized.Thirdly,through the research and analysis of the decision-making and scheduling process of the core energy scheduling strategy(two-stage method),this paper establishes a joint operation model of microgrid cyber system and physical system.Taking the economy(microgrid interaction cost,electric vehicle user cost)and reliability(expected energy not supplied,loss of load probability)as the measurement indexes,we have developed a quantitative analysis framework with small scheduling time granularity,built-in energy scheduling strategy,various cyber system functions and expandable conditions to achieve the integration of cyber system functions and physical component state conversion.Then,the impact quantification method based on the framework can accurately quantify the impact of cyber system on the operation performance of microgrid energy scheduling strategy.Finally,the simulation software MATLAB is used to model and simulate the cyberphysical microgrid.By comparing and analyzing the economic and reliability indexes of three operation modes(disordered mode;real-time control mode;cyber-physical system joint operation mode),the reason why the failure of cyber system can not be ignored is explained in detail.In addition,through the sensitivity analysis from three aspects(parameter value comparison;information component failure rate comparison;topology structure comparison),the sensitive factors that affect the operation performance and the key nodes of cyber system are accurately identified,and the system performance is effectively improved by reasonably adding components,which can provide help in the early planning,later operation and maintenance stage of the system..