Biblio

Real-time supervisory control and data acquisition (SCADA) systems use remote terminal units (RTUs) to monitor and manage the flow of power at electrical substations. As their connectivity to different utility and private networks increases, RTUs are becoming more vulnerable to cyber-attacks. Some attacks seek to access RTUs to directly control power system devices with the intent to shed load or cause equipment damage. Other attacks (such as denial-of-service) target network availability and seek to block, delay, or corrupt communications between the RTU and the control center. In the most severe case, when communications are entirely blocked, the loss of an RTU can cause the power system to become unobservable. It is important to understand how losing an RTU impacts the system state (bus voltage magnitudes and angles). The system state is determined by the state estimator and serves as the input to other critical EMS applications. There is currently no systematic approach for assessing the cyber-physical impact of losing RTUs. This paper proposes a methodology for N-1 RTU cyber-physical security assessment that could benefit power system control and operation. We demonstrate our approach on the IEEE 14-bus system as well as on a synthetic 200-bus system.

Electrical substations are crucial for power grids. A number of international standards, such as IEC 60870 and 61850, have emerged to enable remote and automated control over substations. However, owing to insufficient security consideration in their design and implementation, the resulting systems could be vulnerable to cyber attacks. As a result, the modernization of a large number of substations dramatically increases the scale of potential damage successful attacks can cause on power grids. To counter such a risk, one promising direction is to design and deploy an additional layer of defense at the substations. However, it remains a challenge to evaluate various substation cybersecurity solutions in a realistic environment. In this paper, we present the design and implementation of SoftGrid, a software-based smart grid testbed for evaluating the effectiveness, performance, and interoperability of various security solutions implemented to protect the remote control interface of substations. We demonstrate the capability and usefulness of SoftGrid through a concrete case study. We plan to open-source SoftGrid to facilitate security research in related areas.