Cyber Resilience Metrics for Bulk Power Systems
- Bheshaj Krishnappa, ReliabilityFirst
The North American BPS is a complex technological network, and its cyber-physical interconnectivity allows for long-distance power transmission but presents a “surface” for cyber attacks. The potential for disruptions in BPS can be attributed to the dependence and the vulnerability of the networks interconnecting substations and control centers. There is a need to develop cyber resilience metrics for BPS to provide quantitative insights into ability of security controls to ensure operational resilience and development of cost-effective mitigation plan. In this activity, we propose to measure cyber resilience for power systems as a function of robustness, redundancy, resourcefulness and rapidity. We will develop analytical models for each of the aforementioned properties for the networks interconnecting sub stations and control center. We will formulate the analytic models as multi-level directed acyclic graphs and interdependent coupled networks. We will identify the design parameters, such as firewall rules, network paths, node recovery time, backup resources available, etc., which achieve the desired resilience by measuring robustness, redundancy, resourcefulness and rapidity. We will model the relationship between the network parameters and resilience levels which will be benefit the stakeholders of BPS. Through the collaborative research agreement with RF, representative network topologies and appropriate data will be shared to aid in a high-fidelity model. RF is one of the eight FERC approved regional entities responsible for ensuring the reliability of the BPS. RF is responsible for the reliability and security of the power system within a footprint which spans 13 states in the Eastern Interconnection. Their mission involves developing, monitoring, and enforcing compliance with the FERC approved reliability standards for owners, operators and users of the BPS (approximately 350 utilities); developing and disseminating timely and instructive information to enhance the reliability of the BPS; and provide seasonal and long-term assessments of BPS reliability.
We will develop cyber resilience metrics for BPS based on an analytical framework that builds on models for physical attacks, but differentiates from these by considering the additional complexity introduced by the cyber asepcts of modern BPS. The availability of resilience metrics will aid in identifying the most vulnerable devices and impact on operation of the power grid and security controls which are cost-effective and provide appreciable tradeoff between protection and performance.
How does this research activity address the Roadmap to Achieve Energy Delivery Systems Cybersecurity?
This activity falls under “Assess and Monitor Risk”. There is a need to understand and quantify the security posture of EDS. In our activity, we are focusing on the BPS sector within the EDS ecosystem. The availability of resilience metrics will support risk management decision making in BPS sectors. It will also facilitate the ability of operators to prioritize corrective actions. In addition, the availability of cyber resilience metrics will motivate operators to continually assess their response to risks to cyber threats.