Assessment Methods And Communication Mechanisms Of Information Security In Electric Power Systems

The information security of power systems derives from communication and information systems,but effects on the operation of power systems.According to the partition structure of power information architecture,the production and control region that are mainly composed by power monitoring and control systems is the cross-point of tightly coupled information architecture and power architecture of power system.On the one hand,this kind of information security issues,easily lead to serious consequences,and very likely affect the stability of power system operation.On the other hand,compared with conventional computer network,such system in the security threats,security requirements,accident consequences, accident sample,information architecture and control flow,etc.have shown some new information security features,leading to conventional methods of information security can not be completely applicable.Therefore,this thesis focuses on the information security assessment methods and security communication mechanisms of power system,and takes the network based power monitoring and control systems as study object,tries to solve following problems.1.Vulnerability assessment of power monitoring and control systems.Through the formal definition,the attack graph based vulnerability analysis model is defined for power monitoring and control systems.Further more,considering the information security properties,an AHP-TOPSIS based vulnerability quantification method is designed.Finally,a studying instace are construced according to IEC 61850,the validity and rationality of this method is verified by comparison of results calculated by different security scheme.2.Asset identification of power monitoring and control systems.Taking substation automation systems as typical study object of power monitoring and control systems.On the analysis of difficulities,a complete assets identification method is proposed from three aspects,including asset classification,task identification,and asset quantification. Furthermore,a study instance is constructed based on IEC 61850 to verify the effectiveness of proposed method.3.Reliability assessment of power monitoring and control systems.Taking wide area measurement systems(WAMS) as typical study object of power monitoring and control systems.Reliability analysis of the WAMS is divided into three parts,including control center,data acquisition subsystem,and wide-area communication system such as SDH. Furthermore,the system availability is defined as the reliability index of WAMS.Using the WAMS system of IEEE-14 testing system as study instance,the availability curve can be calculated.4.Designing method for security communication mechanisms of power systems. Taking the communication models in IEC 61850 as study object,the designing related factors of security communication mechiansms are analyzed,and thus construct the designing framework for security communication mechiansms of power systems.Based on the designing framework,two instance studies of unsolved problems are developed. One is a security communication mechanism for remote monitoring and control of wind power plants,which could be used to fulfil the security requirements without any change to SOAP messages of IEC 61400-25.Another one is a security communication mechanism of substation remote configuration,which could meet the security requirements of SCL configurations via the definion of SCL security extension and security process method.