Software-Defined Vehicle-to-Grid And Its Security Architecture

As a new power grid technology,the smart grid provides the visibility and intelligent control of the grid system,greatly optimizing the operation process of the power grid and the management of the managers.As a new technology in Smart Grid,Vehicle-to-Grid(V2G)technology constructs a flexible and extensible interoperation platform between electric vehicles and grids,in which the bidirectional charging can be performed between vehicles and grid based on the demands.With the expansion of V2G network,V2G faces a variety of problems,such as heterogeneous network technology,configuration curing and network management complicated,and also V2G faces the communication network security issues.Software Definition Network(SDN)is an advanced next-generation network architecture that provides flexible control by separating the control plane from the data plane.The control plane has the characteristic of logical centralization and programmability.The characteristic of SDN can accelerate network innovation,greatly simplifying network management.Flexible configuration of network can make the system more scalable,safety and collaborative,which make SDN become a potential communication architecture in V2G.At present,SDN technology has been applied to the smart grid,but based on SDN to achieve the new V2G architecture remains to be resolved.1)In this context,this paper establishes a software-defined V2G(SD-V2G)architecture by modeling the V2G,SDN controller and Openflow switch by IEC61850 standard.2)The function of SD-V2G data plane includes real-time measurement,statistics information,charging and discharging data acquisition and local processing.The function of the SD-V2G control plane is realized in the server of the V2G charging station.It includes functions such as charging and discharging data management,charging station event management,collecting link information and policy distribution.The function of the SD-V2G application plane dynamically and centralized manage grid application,such as alarm processing,remote monitoring and various types of network and security applications.3)This paper designed the southbound and northbound interface of SD-V2G.Representational State Transfer(REST)is the Northbound Interface(NBI)and Extensible Messaging and Presence Protocol(XMPP)protocol is the southbound interface(SBI).In order to ensure the confidentiality,integrity and non-repudiation of the V2G system,a software-defined V2G security architecture and a V2G secure communication mechanism based on hierarchical key management are designed.Software defined V2G security architecture achieve the security function(including symmetric encryption algorithm,HASH algorithm,asymmetric encryption algorithm,authentication and encrypted transmission,etc.)flexibly.At the same time,a secure communication mechanism is established in SD-V2G.Key management mechanism plays an important role in secure communication mechanism to ensure information security.Therefore,this paper designed a hierarchical key management mechanism to ensure the safety of SD-V2G communication process.