169 research outputs found

    Impact Assessment of Hypothesized Cyberattacks on Interconnected Bulk Power Systems

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    The first-ever Ukraine cyberattack on power grid has proven its devastation by hacking into their critical cyber assets. With administrative privileges accessing substation networks/local control centers, one intelligent way of coordinated cyberattacks is to execute a series of disruptive switching executions on multiple substations using compromised supervisory control and data acquisition (SCADA) systems. These actions can cause significant impacts to an interconnected power grid. Unlike the previous power blackouts, such high-impact initiating events can aggravate operating conditions, initiating instability that may lead to system-wide cascading failure. A systemic evaluation of "nightmare" scenarios is highly desirable for asset owners to manage and prioritize the maintenance and investment in protecting their cyberinfrastructure. This survey paper is a conceptual expansion of real-time monitoring, anomaly detection, impact analyses, and mitigation (RAIM) framework that emphasizes on the resulting impacts, both on steady-state and dynamic aspects of power system stability. Hypothetically, we associate the combinatorial analyses of steady state on substations/components outages and dynamics of the sequential switching orders as part of the permutation. The expanded framework includes (1) critical/noncritical combination verification, (2) cascade confirmation, and (3) combination re-evaluation. This paper ends with a discussion of the open issues for metrics and future design pertaining the impact quantification of cyber-related contingencies

    Cyber-Based Contingency Analysis and Insurance Implications of Power Grid

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    Cybersecurity for power communication infrastructure is a serious subject that has been discussed for a decade since the first North American Electric Reliability Corporation (NERC) critical infrastructure protection (CIP) initiative in 2006. Its credibility on plausibility has been evidenced by attack events in the recent past. Although this is a very high impact, rare probability event, the establishment of quantitative measures would help asset owners in making a series of investment decisions. First, this dissertation tackles attackers\u27 strategies based on the current communication architecture between remote IP-based (unmanned) power substations and energy control centers. Hypothetically, the identification of intrusion paths will lead to the worst-case scenarios that the attackers could do harm to the grid, e.g., how this switching attack may perturb to future cascading outages within a control area when an IP-based substation is compromised. Systematic approaches are proposed in this dissertation on how to systematically determine pivotal substations and how investment can be prioritized to maintain and appropriate a reasonable investment in protecting their existing cyberinfrastructure. More specifically, the second essay of this dissertation focuses on digital protecting relaying, which could have similar detrimental effects on the overall grid\u27s stability. The R-k contingency analyses are proposed to verify with steady-state and dynamic simulations to ensure consistencies of simulation outcome in the proposed modeling in a power system. This is under the assumption that attackers are able to enumerate all electronic devices and computers within a compromised substation network. The essay also assists stakeholders (the defenders) in planning out exhaustively to identify the critical digital relays to be deployed in substations. The systematic methods are the combinatorial evaluation to incorporate the simulated statistics in the proposed metrics that are used based on the physics and simulation studies using existing power system tools. Finally, a risk transfer mechanism of cyber insurance against disruptive switching attacks is studied comprehensively based on the aforementioned two attackers\u27 tactics. The evaluation hypothetically assesses the occurrence of anomalies and how these footprints of attackers can lead to a potential cascading blackout as well as to restore the power back to normal stage. The research proposes a framework of cyber insurance premium calculation based on the ruin probability theory, by modeling potential electronic intrusion and its direct impacts. This preliminary actuarial model can further improve the security of the protective parameters of the critical infrastructure via incentivizing investment in security technologies

    Iec 61850-based communication networks of distribution system against cyber and physical failures

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    This paper proposes a decentralized control approach using a co-simulation platform to monitor protective elements and provide complete protection scheme for distribution systems. Real time measurements are obtained by interfacing the system model in RSCAD/RTDS with SEL 421 protective relays and publish/subscribe the voltage and current signals of the buses and transmission lines based on IEC 61850 communication protocol to isolate the fault correctly. The proposed technique helps to identify the location of the fault and introduces primary and buck protection for the system. The communication networks assists in facing cyber and physical threats and finding a new path for healthy relays to remove faults from the system. This technique is investigated on an IEEE 14 bus system for all possible fault locations. The proposed scheme can clear the fault by isolating the minimum part of the system and improving the endurance of the power in it. The system shows the smooth information flow between the cyber and physical parts to isolate faults in it in different cases

    Prototype mixed-signal hardware for public safety radio interoperability

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    In performing their required duties public safety personnel from differing departments often need to communicate with one another using their in-car radios. However, in many cases, especially involving small departments, this interoperability doesn\u27t exist. A prototype circuit design has been developed and tested within the laboratory using two common radio systems: EFJohnson and Motorola. The preliminary results have shown successful operation as a system gateway between the two radio systems with good performance regarding audio signal latency and minimizing the push-to-talk signal generation delay

    Expert Teams: Do Shared Mental Models of Team Members make a Difference?

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    The purpose of the present thesis was to investigate whether and how familiarity influences coordination, resilience, and efficiency in high performance teams in safetycritical organizations. Research has accumulated solid support for the general presumption that shared mental models are associated with team effectiveness (see overview, Kozlowski & Ilgen, 2006). Unfortunately, familiarity and shared mental models have seldom been the subject of investigation. This is surprising since the importance of team members having a shared understanding is underlined in dynamic situations that require high levels of flexibility and adaptability in the team (Cannon-Bowers et al., 1993; Salas & Fiore, 2004). The first study investigated whether knowledge about individual team members would augment the effect of operational skills in predicting operational effectiveness in trained expert teams. The second study investigated the consequences of shared mental models (SMM) of team members in teams that are forced to coordinate their activities towards a shared goal in a distributed team setting. The third study investigated whether shared mental models of team members would transfer across new tasks or situations and, through better coordination, result in improved efficiency and less physiological arousal. Study 1 included samples from 24 active duty officers who made up four submarine attack teams. Studies 2 and 3 included a total of 177 cadets from the Royal Norwegian Naval Academy. The findings from these three studies indicate that familiar teams used coordination strategies that enhanced efficiency. The coordination strategies used by familiar teams are characterized by less overt communication (statements per minute) during high workload (Study 1), a higher global anticipation rate (Study 2), and more adaptability and back-up statements during cross-training (Study 3). In addition, familiar teams showed more overt communication (e.g., confirmation) when confronted with a novel situation (Studies 2 and 3). Familiar teams outperformed unfamiliar teams, being more accurate, quicker and achieving greater mission success (i.e., more hits). Familiar teams were more physiologically aroused (HR) during low workload (Study 2), and less during high workload (Study 1), recovery (Studies 2 and 3), and decreasingly so during training (Study 3). These three studies extend previous research by presenting new empirical data on the significance of shared mental models of team members. Study 1 demonstrated that knowledge about team members (i.e., shared mental models of team members) adds to performance over and above the contribution of operational skills (Aim 1). Studies 2 confirmed Study 1 (within teams) and provide empirical evidence for the effect of shared mental models of team members in distributed teams (Aim 2). The findings from Study 3 suggest that shared mental models of team members are transferable across tasks and enhance the effects of cross-training (Aim 3). All studies extend previous research, but Study 3 in particular indicates that shared mental models of team members are distinctly different from transactive memory systems (Aim 3). Hence, a shared mental model of team members represents an independent, adaptive asset at team level that enhances team performance and efficiency. These studies are the first to provide empirical evidence in support of the notion that shared mental models of team members are a mechanism that improves teams’ efficiency, resilience, and coordination. This thesis confirms shared mental models of team members as an important and independent construct with an added value in relation to team performance and efficiency. It thus expands previous knowledge, where the focus has been on equipment, tasks, and team interaction. The findings are a contribution to and fill an important gap in the literature on Shared Mental Models. Implications are discussed for training, staffing and safety issues in teams in safety-critical organizations

    Probabilistic Risk Assessment Procedures Guide for NASA Managers and Practitioners (Second Edition)

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    Probabilistic Risk Assessment (PRA) is a comprehensive, structured, and logical analysis method aimed at identifying and assessing risks in complex technological systems for the purpose of cost-effectively improving their safety and performance. NASA's objective is to better understand and effectively manage risk, and thus more effectively ensure mission and programmatic success, and to achieve and maintain high safety standards at NASA. NASA intends to use risk assessment in its programs and projects to support optimal management decision making for the improvement of safety and program performance. In addition to using quantitative/probabilistic risk assessment to improve safety and enhance the safety decision process, NASA has incorporated quantitative risk assessment into its system safety assessment process, which until now has relied primarily on a qualitative representation of risk. Also, NASA has recently adopted the Risk-Informed Decision Making (RIDM) process [1-1] as a valuable addition to supplement existing deterministic and experience-based engineering methods and tools. Over the years, NASA has been a leader in most of the technologies it has employed in its programs. One would think that PRA should be no exception. In fact, it would be natural for NASA to be a leader in PRA because, as a technology pioneer, NASA uses risk assessment and management implicitly or explicitly on a daily basis. NASA has probabilistic safety requirements (thresholds and goals) for crew transportation system missions to the International Space Station (ISS) [1-2]. NASA intends to have probabilistic requirements for any new human spaceflight transportation system acquisition. Methods to perform risk and reliability assessment in the early 1960s originated in U.S. aerospace and missile programs. Fault tree analysis (FTA) is an example. It would have been a reasonable extrapolation to expect that NASA would also become the world leader in the application of PRA. That was, however, not to happen. Early in the Apollo program, estimates of the probability for a successful roundtrip human mission to the moon yielded disappointingly low (and suspect) values and NASA became discouraged from further performing quantitative risk analyses until some two decades later when the methods were more refined, rigorous, and repeatable. Instead, NASA decided to rely primarily on the Hazard Analysis (HA) and Failure Modes and Effects Analysis (FMEA) methods for system safety assessment

    Nuclear Power - Operation, Safety and Environment

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    Today's nuclear reactors are safe and highly efficient energy systems that offer electricity and a multitude of co-generation energy products ranging from potable water to heat for industrial applications. At the same time, catastrophic earthquake and tsunami events in Japan resulted in the nuclear accident that forced us to rethink our approach to nuclear safety, design requirements and facilitated growing interests in advanced nuclear energy systems, next generation nuclear reactors, which are inherently capable to withstand natural disasters and avoid catastrophic consequences without any environmental impact. This book is one in a series of books on nuclear power published by InTech. Under the single-volume cover, we put together such topics as operation, safety, environment and radiation effects. The book is not offering a comprehensive coverage of the material in each area. Instead, selected themes are highlighted by authors of individual chapters representing contemporary interests worldwide. With all diversity of topics in 16 chapters, the integrated system analysis approach of nuclear power operation, safety and environment is the common thread. The goal of the book is to bring nuclear power to our readers as one of the promising energy sources that has a unique potential to meet energy demands with minimized environmental impact, near-zero carbon footprint, and competitive economics via robust potential applications. The book targets everyone as its potential readership groups - students, researchers and practitioners - who are interested to learn about nuclear power

    Safety and Reliability - Safe Societies in a Changing World

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    The contributions cover a wide range of methodologies and application areas for safety and reliability that contribute to safe societies in a changing world. These methodologies and applications include: - foundations of risk and reliability assessment and management - mathematical methods in reliability and safety - risk assessment - risk management - system reliability - uncertainty analysis - digitalization and big data - prognostics and system health management - occupational safety - accident and incident modeling - maintenance modeling and applications - simulation for safety and reliability analysis - dynamic risk and barrier management - organizational factors and safety culture - human factors and human reliability - resilience engineering - structural reliability - natural hazards - security - economic analysis in risk managemen

    Joint University Program for Air Transportation Research, 1990-1991

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    The goals of this program are consistent with the interests of both NASA and the FAA in furthering the safety and efficiency of the National Airspace System. Research carried out at the Massachusetts Institute of Technology (MIT), Ohio University, and Princeton University are covered. Topics studied include passive infrared ice detection for helicopters, the cockpit display of hazardous windshear information, fault detection and isolation for multisensor navigation systems, neural networks for aircraft system identification, and intelligent failure tolerant control
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