Research On Methods For Identifying Emergency Capacity Shortage Of Urban Power Grid

Critical infrastructure is the general term of a set of inter-dependent complex dynamic network systems composed of systems of power,telecommunication,traffic,water supply and water treatment,energy transportation,finance,public health and emergency services that support social operation.With the rapid development of city economic,people are relying on the services provided by critical infrastructure.Power grid is an important critical infrastructure.It maintains the common life of people and stable operation of other critical infrastructure such as telecommunication,traffic and water supply.Cascading disasters have features of multi-factor,multi-subject,multi-stage,complexity,dynamics,uncertatinty and so on.They have huge destructive effect on urban power.Power grid system is likely to have cascading failure because of the function relevance among its sub systems.If power grid is destroyed by cascading disasters,it will cause huge losses for human society.At the stage of emergency preparedness,it is important issuse concerned by emergency decision makers that how to evaluate and improve power emergency capacity at the stage of emergency response.Relevant research on capacity evaluation mainly focus on the overall evaluation of emergency capacity.However,the work is huge and not easy to obtain effective conclusions.The researches on vulnerability give the analysis perspective of studying emergency systems from the weak links.But the researches focus on the identification of physical defects,and emergency system risk analysis needs to consider comprehesively on every aspect influencing CI disaster reponse.Researching with emergency capacity as object has favor on considering every risk elements systematically and directly discovers the weak links of emergency systems.In the planning stage of emergency preparedness,it is a well-known practice as well as an urgent theorical problem that how to recognize capacity shortage.This paper conducts research work about this sientific problem as follows with urban power grid as research objects.Firstly,analyze the influence of cascading hazards to urban power grid,and generalize relevant factors and their relationship.Based on power emergency capacity concept and capacity system,propose the concept of capacity shortage in terms of the balance between real emergency capacity and goal capacity.According to the identifying logic,dividing the constructive factors of capacity shortage problem into four categories,that are goal scenarios,sceanrio evolution probability,capacity shortage identification list,capacity shotage evluation indicators and standards.According to the Known-Unclear-Presumed method,the constructive factors can be noted as known,unclear or presumed in terms of their certainty.And divide capacity shortage identification problem into defiend,fuzzy and uncertain based on the status of construcive factors at the stage of problem analyasis.In terms of the three status of constructive factors,construct classification identifying system of power emergency capacity shortage.Secondly,in terms of defined capacity shortage identification problem,propose method based on case referring for identifying emergency capacity shortage of power grid.This method based on power system emergency task system,consider the direct influence relationship among emergency capacity shortage.It has favor on solving problem of evluation lacking relevance.This method rapidly and effectively identifies emergency capacity shortage of power grid based on case referring,reducing work amount of evalutaion,having favor on solving problem of evaluation lacking pertinence.This mehod adopts historical cases as reference and standard,assuring the objectiveness of evluation,having favor on solving problem of evluation lacking prediction.Thirdly,in terms of fuzzy capacity shortage identification problem,propose method based on mess maps for identifying emergency capacity shortage of power grid.Emergency messes are one of social messes,describe the complexity and interaction of emergency management.This method proposes mess reducing theory,identifying power emergency shortage from the aspect of reducing uncertainty based on mess maps,stating mess map constructing process of capacity shortage analysis under certain cascading disaster scenarios.The process includes mess map constructing preparedness,initializing mess maps,relevant problem identifying,causal relationship,constructing mess maps,and so on.Mess map has problem relevance and causal relationship identifying as key issues,inducing the values of constructive factors under new scenarios from known cases and knowledge resources,having favor on solving problems of unreliable decision source and incomplete knowledge.Next,in terms of uncertain capacity shortage identification problem,propose method based on scenario presuming for identifying emergency capacity shortage of power grid.Under the background of scenario uncertainty,it is hard to directly predict scenarios of future disasters,causing scenario presetting difficulty of capacity shortage analysis.The scenario presuming of capacity shortage identification refers to at the stage of emergency preparedness planning,creating capacity shortage identification cases adapting to real demands,reducing uncertainty of goal scenarios by designing and planning scenarios.Presuming analysis can be divided into four stages that are scenario inserting,scenario presuming,emergency project simulating,emergency effect evaluation and presuming project choosing,and capacity shortage identification.Scenario presuming can make emergency decision makers modify goal scenarios according to real conditions combining demonds of emergency managers to emergency effects,having favor on improving scenario pertinence of capacity shortage identifying.Again,propose ontology configuration hierarchical system of capacity shortage identification,including ontology construction,sharing and matching.From the knowledge needs of capacity shortage identification,constructing the scenario ontologies,project ontologies and evaluation ontologies of capacity shortage identifying.Based on ontolgies constructed above,constructing knowledge ontology sharing framework of capacity shortage identification.In terms of semantic conflicting problem of ontology configuration,propose ontology matching theory of capacity shortage identification,using ontology relevance maps as the visualization tool of ontology matching.Ontology configuration overcomes the defect of inconsistence between model construction real operation in traditional ontology configuration methods,focusing on ontology sharing,linking ontology modeling and ontology matching,having favor on realizing cross-organization flowing of knowledge and facilitating decision making.Finally,designing a uniform capacity shortage identificaiton process,that is capacity shortage identification routine.Based on capacity shortage identification theories and methods above,propose the basic features and contents of capacity shortage identification routine,desiging operation mode,implementation steps and ontology matching routine of capacity shortage identification,stating the basic theory of capacity shortage identification routine from aspects of theoretical analysis and real operation.Finally,stating the rationality and validity of capacity shortage identification routine with an use case.