Software Defined Networking enabled Resilience for IEC 61850-based Substation Communication Systems

The resilience of smart grid hinges on its ability to deliver service in a timely and reliable manner even in the presence of persistent attacks. While digital communications in the smart grid present benefits such as higher data transfer rates, they also increase the attack surfaces, permitting IP-based network attacks, such as DoS attacks. To mitigate these emerging attacks and ensure power system requirements are met, there is a need to incorporate resilient capabilities in smart grid. Security risk assessment is a critical component to ensure smart grid cyber resilience. However, there are few security risk assessment approaches for ensuring resilience in smart grid. In this paper, we develop a security score model within a Software Defined Network (SDN) framework for IEC 61850-based substation communication network. The SDN framework incorporates the security risk score model and SDN principles are leveraged to achieve cyber resilience. We illustrate how SDN relieves our smart grid network of congestion and improves timing performance of IEC 61850 type messages, making them time compliant. The security score model also incorporates the criticality of device in the IEC 61850 network. We implement the security score model in Software Defined Network, which provides the ability to reconfigure the IEC 61850 network in real time. We evaluate the model in an experimental GENI testbed characterized by wide-area network dynamics and realistic traffic scenarios to address IEC 61850 network attacks.