Reliability Analysis of Power Grids and Its Interdependent Infrastructures

Reliability Analysis of Power Grids and Its Interdependent Infrastructures
Author: Upama Nakarmi
Publisher:
Total Pages: 151
Release: 2020
Genre: Battery charging stations (Electric vehicles)
ISBN:

Large blackouts with significant societal and economic impacts result from cascade of failures in the transmission network of power grids. Understanding and mitigating cascading failures in power grids is challenging due to the large number of components and their complex interactions, wherein, in addition to the physical topology of the system, the physics of power flow and functional dependencies among components largely affect the spatial distribution and propagation of failures. In this dissertation, data-driven interaction graphs, which help in capturing the underlying interactions and influences among the components during cascading failures, are used for capturing the non-local nature of propagation of failures as well as for simplifying the modeling and analysis of cascades. Particularly, influence and correlation graphs are constructed for revealing and comparing various types of interactions/influences during cascades. In addition, as a step towards analyzing cascades, community structures in the interaction graphs, which bear critical information about cascade processes and the role of system components during cascades are identified. The key idea behind using community structures for analyzing cascades is that a cascade entering a community is likely to reach to most of the other members of the same community while less likely to reach to other communities. Thus, community structures significantly impact cascade behavior by trapping failures within communities. Further, a centrality measure based on the community structures is proposed to identify critical components of the system, which their protection can help in containing failures within a community and prevent the propagation of failures to large sections of the power grid. Various criticality evaluation techniques, including data-driven, epidemic simulation-based, power system simulation-based and graph-based, have been used to verify the importance of the identified critical components in the cascade process and compare them with those identified by traditional centrality measures. Moreover, it has been shown that the loading level of the power grid impacts the interaction graph and consequently, the community structure and criticality of the components in the cascade process. Furthermore, a Markov chain model is designed based on the community structures embedded in the data-driven interaction graphs of power grids. This model exploits the properties of community structures in interactions to enable the probabilistic analysis of cascade sizes in power grids. The trapping property of communities is extensively used to show that the probability distribution of cascade sizes exhibit power-law behavior as observed in previous studies and historical data. Finally, an integrated framework based on the influence model, a networked Markov chain framework, is proposed for modeling the integrated power grid and transportation infrastructures, through one source of their interdependency i.e., electric-vehicle (EV) charging stations. The interactions based on the rules and policies governing their internal and interaction dynamics is captured. Particularly, the proposed integrated framework is used to design an algorithm for assigning dynamic charging prices for the EV charging infrastructure with the goal of increasing the likelihood of having balanced charging and electric infrastructures. The proposed scheme for charging prices is traffic and power aware as the states and interactions of transportation and power infrastructures are captured in the integrated framework. Finally, the critical role of cyber infrastructure in enabling such collaborative solutions is also discussed.

A General Methodology for Inferring Failure Propagation Process from Post-disaster Disruptions Data

A General Methodology for Inferring Failure Propagation Process from Post-disaster Disruptions Data
Author: Xiangyang Guan
Publisher:
Total Pages: 155
Release: 2018
Genre:
ISBN:

Cascading failures, where failures propagate from an initially small portion of a system to a much larger portion or even the entire system, are ubiquitous phenomenon in a number of natural, social and technical systems, and have seen instances in the formation of large-scale disasters such as the recent devastations caused by Hurricanes Harvey, Irma and Maria. Understanding and ultimately controlling the dynamics of cascading failures are critical for securing the functionality of those systems, and ensuring the wellbeing of the people and the society. This, however, is a challenging task due to the complexities in the cascading failure dynamics. In this dissertation, a novel methodology to model, infer and reconstruct cascading failure dynamics is proposed, tested and validated. A survival-analysis-based formulation is derived to mathematically describe how external factors and failure propagations give rise to observed failure outcomes, and maximum likelihood estimation is employed to estimate the model parameters. With the estimated parameters, cascading failure dynamics, including the temporal-spatial patterns of failure spreading and node-to-node failure propagation patterns, are reconstructed. This approach is applied to four simulation studies: (a) cascading failures in interdependent power and transportation networks in New York City (NYC) during Hurricane Sandy; (b) a hypothetical influenza epidemic in NYC; (c) a congestion cascade scenario in the Sioux-Falls benchmark network; and (d) cascading power outages in the Wood-Wollenberg 6-bus benchmark system. The inference results returned by the proposed approach and simulation results are compared for each simulation study. All comparisons in the simulation studies return consistent patterns between the inferred cascading failure dynamics and simulated cascading failure dynamics, suggesting the accuracy, robustness and generalizability of the proposed methodology. This dissertation demonstrates strong potential of broad impact both within and beyond the domain of civil engineering. The civil infrastructure systems like transportation and power are constantly under the threat of cascading failures. A methodology for understanding the cascading failure dynamics, especially the node-to-node failure propagation patterns that have been overlooked in existing research, will open a channel to more efficiently enhancing the resilience of infrastructure systems against malfunctioning and assisting emergency response to effectively contain the impact of disruptive events such as natural disasters, terrorist attacks and internal performance fluctuations. More broadly, cascading failures are also observed in a number of other disciplines such as information science, social science, epidemiology, biology and physics. Researchers in those disciplines are faced with similar challenges in learning cascading failure dynamics. The present research constructs a universal methodological framework for understanding and controlling cascading failures, which is applicable to a broad range of systems studied by researchers from various disciplines. It thus will potentially facilitate the inter disciplinary communications that will foster more efficient and high-impact research in each of the individual fields.

Power Systems Resilience

Power Systems Resilience
Author: Naser Mahdavi Tabatabaei
Publisher: Springer
Total Pages: 366
Release: 2018-08-16
Genre: Technology & Engineering
ISBN: 3319944428

This book presents intuitive explanations of the principles and applications of power system resiliency, as well as a number of straightforward and practical methods for the impact analysis of risk events on power system operations. It also describes the challenges of modelling, distribution networks, optimal scheduling, multi-stage planning, deliberate attacks, cyber-physical systems and SCADA-based smart grids, and how to overcome these challenges. Further, it highlights the resiliency issues using various methods, including strengthening the system against high impact events with low frequency and the fast recovery of the system properties. A large number of specialists have collaborated to provide innovative solutions and research in power systems resiliency. They discuss the fundamentals and contemporary materials of power systems resiliency, theoretical and practical issues, as well as current issues and methods for controlling the risk attacks and other threats to AC power systems. The book includes theoretical research, significant results, case studies, and practical implementation processes to offer insights into electric power and engineering and energy systems. Showing how systems should respond in case of malicious attacks, and helping readers to decide on the best approaches, this book is essential reading for electrical engineers, researchers and specialists. The book is also useful as a reference for undergraduate and graduate students studying the resiliency and reliability of power systems.

Risk and Interdependencies in Critical Infrastructures

Risk and Interdependencies in Critical Infrastructures
Author: Per Hokstad
Publisher: Springer Science & Business Media
Total Pages: 250
Release: 2012-12-18
Genre: Technology & Engineering
ISBN: 1447146611

Today’s society is completely dependent on critical networks such as water supply, sewage, electricity, ICT and transportation. Risk and vulnerability analyses are needed to grasp the impact of threats and hazards. However, these become quite complex as there are strong interdependencies both within and between infrastructure systems. Risk and Interdependencies in Critical Infrastructures: A guideline for analysis provides methods for analyzing risks and interdependencies of critical infrastructures. A number of analysis approaches are described and are adapted to each of these infrastructures. Various approaches are also revised, and all are supported by several examples and illustrations. Particular emphasis is given to the analysis of various interdependencies that often exist between the infrastructures. Risk and Interdependencies in Critical Infrastructures: A guideline for analysis provides a good tool to identify the hazards that are threatening your infrastructures, and will enhance the understanding on how these threats can propagate throughout the system and also affect other infrastructures, thereby identifying useful risk reducing measures. It is essential reading for municipalities and infrastructure owners that are obliged to know about and prepare for the risks and vulnerabilities of the critical infrastructures for which they are responsible.

Robust Stability Analysis for Large-scale Power Systems

Robust Stability Analysis for Large-scale Power Systems
Author: Richard Yi Zhang
Publisher:
Total Pages: 154
Release: 2017
Genre:
ISBN:

Innovations in electric power systems, such as renewable energy, demand-side participation, and electric vehicles, are all expected to increase variability and uncertainty, making stability verification more challenging. This thesis extends the technique of robust stability analysis to large-scale electric power systems under uncertainty. In the first part of this thesis, we examine the use of the technique to solve real problems faced by grid operators. We present two case studies: small-signal stability for distributed renewables on the IEEE 118-bus test system, and large-signal stability for a microgrid system. In each case study, we show that robust stability analysis can be used to compute stability margins for entire collections of uncertain scenarios. In the second part of this thesis, we develop scalable algorithms to solve robust stability analysis problems on large-scale power systems. We use preconditioned iterative methods to solve the Newton direction computation in the interior-point method, in order to avoid the O(n6) time complexity associated with a dense-matrix approach. The per-iteration costs of the iterative methods are reduced to O(n3) through a hierarchical block-diagonal-plus-low-rank structure in the data matrices. We provide evidence that the methods converge to an [epsilon]-accurate solution in O(1=[square root of ] [epsilon]) iterations, and characterize two broad classes of problems for which the enhanced convergence is guaranteed.

Power Systems Modeling for Multiple Infrastructure Damage and Repair Simulations

Power Systems Modeling for Multiple Infrastructure Damage and Repair Simulations
Author:
Publisher:
Total Pages:
Release: 2008
Genre:
ISBN:

The interdependencies that exist within and between infrastructures can cause unexpected system properties to emerge when their components fail due to large disruptions. As witnessed following emergencies such as Hurricane Katrina, the complexities of these interdependencies make it very difficult to effectively recover infrastructure because of the challenges they create in prioritizing the most critical components for repair. The Joint Infrastructure Interdependencies Research Program was initiated by Public Safety Canada (PSC) and the Natural Sciences and Engineering Research Council of Canada (NSERC) in 2005 to research methods for remedying this problem. As a part of this research, the University of British Columbia (UBC) is developing an infrastructure interdependency simulator, named I2Sim, to simulate disasters and develop strategies for dealing with emergencies. Part of this development is to construct a model of the UBC electrical distribution system and interface it with I2Sim. In this research, a general methodology for such a model is presented, which employs an off-the-shelf powerflow modeling tool. In addition, a model of the UBC information technology infrastructure is developed to provide a second infrastructure model to demonstrate the electrical model's usefulness in multi-infrastructure disaster recovery simulations. Simulations with these models have shown that the recovery of this two-infrastructure system can be carried out more effectively following an earthquake if both infrastructures are considered together in the repair approach, rather than individually. This difference was on the order of thirty percent. To extend this research from electrical distribution systems to electrical bulk systems, an interdependency model of the British Columbia Transmission Corporation bulk power network and its communications system was also developed, along with a post-blackout restoration procedure. Using these, simulations of a post-blackout recovery wer.

Lifelines

Lifelines
Author: Stephane Hallegatte
Publisher: World Bank Publications
Total Pages: 220
Release: 2019-07-16
Genre: Business & Economics
ISBN: 1464814317

Infrastructure—electricity, telecommunications, roads, water, and sanitation—are central to people’s lives. Without it, they cannot make a living, stay healthy, and maintain a good quality of life. Access to basic infrastructure is also a key driver of economic development. This report lays out a framework for understanding infrastructure resilience - the ability of infrastructure systems to function and meet users’ needs during and after a natural hazard. It focuses on four infrastructure systems that are essential to economic activity and people’s well-being: power systems, including the generation, transmission, and distribution of electricity; water and sanitation—especially water utilities; transport systems—multiple modes such as road, rail, waterway, and airports, and multiple scales, including urban transit and rural access; and telecommunications, including telephone and Internet connections.