Research On Communication Model And Key Management Scheme Of Smart Meter

Advanced metering infrastructure is an important component of smart grid, in which a large amount of smart meters is used. If these smart meters, produced by different factories, obey different communication standards, the information exchanging between smart meters or smart meters and metering management center would have a big problem of interoperability. Furthermore, smart meters may exchange information with distribution automation system or SCADA for distributed resources. In order to solve this problem, one standard that is open and has strong interoperability should be obeyed, based on which the communication model of smart meters should be uniformly constructed. On the other hand, advanced metering infrastructure may suffer more security threatens as it introduces the open network and communication technologies. Thus those key-based methods, such as encryption and authentication, should be used. How to manage these keys efficiently and safely is the key issue for the information security of advanced metering infrastructure. The above two issues are studied in this paper.(1) Considering the good interoperability and expansibility, along with the application foreground in the whole area of electric power system automation, IEC61850is analyzed to use in the communication modeling of smart meters, which includes information modeling and information exchanging modeling. Firstly, according to the main functions of smart meters, hierarchical information models of smart meter, containing server, logical device, logical node, data object,and data attribute, are constructed with the analysis of the feasibility and deficiency of information modeling; Secondly, according to the communication requirements of smart meters and abstract communication service interface (ACSI), the information exchanging model of smart meter is constructed; Finally, Report model of metering and measuring data is chose as a case to introduce the communication modeling of smart meter.(2) The requirements and difficulties in key management for advanced metering infrastructure are concluded, proposing a new key management scheme. The key management framework of the proposed scheme is constructed based on key graph, and a hierarchical key framework is chose, which synchronously meets the key management requirements of bidirectional communication and three transmission modes; considering the computation ability and storage ability of smart meters, symmetric key encryption algorithm and one-way functions are adopted to reduce the computation time cost and storage cost of keys and key related data; key distribution cost in network would be reduced, so is the probability of distribution data being intercepted, because the key refreshing agreement policy based on metered data and one-way function has been designed. The proposed key management scheme meets the security requirements of advanced metering infrastructure and suits its system features, which is proved by security analysis and performance analysis.