Impediments to survivability of the electric power grid and some collaborative EE-CS research issues to solve them (original) (raw)
Cascading Failures in Power Grids
arXiv (Cornell University), 2022
Critical infrastructures are defined as those physical and cyber-based systems that are essential to the minimum operations of the economy and the government [1, 2]. Since they provide crucial support for the delivery of basic services to almost all segments of society, they form the backbone of any nation's economy. As one of the most complex, largescale networked systems, electric power system has become increasingly automated in the past few decades. However, the increased automation has introduced new vulnerabilities to equipment failures, human errors [3, 4, 5, 6, 7], weather and other natural disasters [8, 9], and physical and cyber-attacks [2, 10]. The ever-increasing system scale and the strong reliance on automatic devices increase the likelihood of turning a local disturbance into a large-scale cascading failure [11, 12, 13, 14, 15, 16]. This kind of wide-area failure may have a catastrophic impact on the whole society. Reports of recent major power system blackouts [17, 18, 19, 20, 21, 22, 23, 24] have shown how several events ranging from minor equipment failure and operator errors to severe weather events (such as forest fires, hurricanes and winter storms) have triggered widespread system wide power disruption affecting millions of customers. This necessitates the development of a framework which would assess the vulnerability of the power grid subjected to any of these events, and thereby allowing energy policy makers to identify critical components in the grid and subsequently allocate budgets to harden them. Statistical analysis of more than 400 blackouts in USA from 1984 to 1999 indicates that a large blackout, though rare, is more likely to occur than expected (heavy tails of a power law distribution) [25]. Therefore, large blackouts require more attention not only due to their higher probability of occurrence, but also due to the enormous societal damage caused by such events. Following this observation, several works [12, 26, 27, 28, 29, 30, 31, 32, 33, 34] have proposed multiple failure models to represent the system dynamics leading to a cascading outage. They have studied cascading failures in power grids using quasi-steady state analysis with DC power flow. With any reactive power component being ignored and the assumption of a flat voltage profile, the DC power flow analysis may produce good approximations under some circumstances, e.g., when performing steady-state planning level studies. However, the increased penetration of converter-based generator technologies, loads and transmission devices have contributed to newly evolved dynamic stability behaviors of the power grid [35]. Major cascading outages are caused when transient rotor angle stability and voltage stability of the power grid are affected [22, 36, 37, 38]. Therefore, a simple cascading failure model based on DC power flow analysis is not a suitable tool to simulate such events. In this paper, we consider the AC power flow model to accurately simulate the actual operating point in the power system. Several physics-based models have been used to study cascading failures in power grid networks and interdependent power and communication networks [39, 40, 41, 42, 43, 44, 45, 46]. The authors have considered the effect of connectivity between layered networks on the cascade probability in each network, and used the sandpile dynamics [47] to represent the cascade tripping of loads in the power grids. These papers are useful in that one can often either obtain analytical results, or carry out large number of simulations to get a detailed understanding of cascade dynamics. The physics based models are simplified models capable of showcasing mechanistic possible behavior of complex network systems, rather than providing precise predictions which requires engineering models with a large number of parameters [46]. The models fail to replicate the actual system conditions in a power grid where a node (or bus) trips due to under-voltage or under-frequency and not due to overload. Further, stability of a power system subjected to cascading events is evaluated either from the network structure point of view (evaluating the degree distribution of nodes) [42, 39, 41, 43] or from the convergence of steady-state power flow solution [26, 27, 28, 29, 30, 31, 32]. Such measures do not necessarily cover all possibilities of grid instability [35], as non-linear mechanisms such as rotor angle stability or voltage collapse are not accurately captured in these methods [36]. In this work, dynamic transient analysis has been used to assess stability of the power system. The reports of certain major blackouts [23, 22] suggest that cascades need not propagate locally due to the complex non-linear nature of the power grid. Furthermore, [24] discusses the various reasons leading to the historic 1996 WSCC outage, the most important being the operation of relays. Based on the NERC data, in more than 70% of the major disturbances, failures in protective relays are found to be a contributing factor [30]. Among these failures, a failed protection system that remains dormant in normal operating conditions and becomes exposed when an abnormal condition in the system forms, is the most troublesome to tackle [48]. Such failures are termed as hidden failures and these are capable of causing widespread cascading failures in the power system network leading to a major blackout [49]. This is equivalent to the human immune system where an immune response following immunization might be more damaging
Energy Infrastructure Survivability, Inherent Limitations, Obstacles and Mitigation Strategies
The blackout of August 14, 2003 affected 8 states and fifty million people and could cost up to 5billion2.YetanotherpressreleaseclaimsitmayhavecostOhiomanufacturers5 billion 2 . Yet another press release claims it may have cost Ohio manufacturers 5billion2.YetanotherpressreleaseclaimsitmayhavecostOhiomanufacturers1.1 billion, based on a poll of 275 companies. Preliminary reports 3 indicate the outage progressed as a chain of relatively minor events, rather than a single catastrophic failure. This is consistent with previous cascading outages, which were caused by a domino reaction 4 . The increasingly ubiquitous use of embedded systems to manage and control our technologically complex society makes our homeland security even more vulnerable. Therefore, knowing how vulnerable such systems are is essential to improving their intrinsic reliability/survivability (in a deregulated environment knowing these important properties is equally essential to the providers).
Casceding failuers in power grids
F ew people consider the complexity of power grid operation when they flip a switch to light a room. Power grids provide electricity to billions of individuals around the globe, often with higher than 99.9% reliability. Because the social structures in most developed countries rely on high-reliability electricity, massive social disruption can result when the power grid fails to deliver energy to customers-urban transportation systems grind to a halt, heating and cooling systems stop, computer systems shut down, and vital services like water, sewer, and communications quickly degrade. In some cases, blackouts can uncover major social unrest, as occurred in the 1977 New York City blackout, which led to widespread rioting and the arrest of more than 3,000 individuals.
Protecting Electricity Networks from Natural Hazards
Human Rights Documents Online
Special thanks go to all contributors to this publication: Eric Andreini (RTE), Brigitte Baltasar (Willis Re), Terry Boston (GO15), Kanat Botbaev (Energy Charter Secretariat), Jed Cohen (Virginia Tech), Christine Eismann (Federal Office of Civil Protection and Disaster Assistance), Torolf Hamm (Willis Re), Alexander Garcia-Aristizabal (AMRA), Matjaž Keršnik (Electro Ljubljana), Martin König (Environment Energy Agency)* , Wolfgang Kröger (Swiss Federal Institute of Technology Zurich), Marc Lehmann (Willis Re), Iryna De Meyer (Energy Charter Secretariat), Hubert Lemmens (GO15), Klaus Moeltner (Virginia Tech), Milka Mumovic (Energy Community Secretariat), Johannes Reichl (Energy Institute at the Johannes Kepler University), Giovanni Sansavini (Swiss Federal Institute of Technology Zurich), Michael Schmidthaler (Energy Institute at the Johannes Kepler University), Alain Steven (GO15), Lubomir Tomik (CESys), Christopher Zobel (Virginia Tech), Friedemann Wenzel (Karlsruhe Institute of Technology). * Martin König passed away shortly after authoring his contribution. He was a leading expert in climate change adaptation research and a valued colleague with a distinguished publication record on disaster risk reduction.
2012
This paper describes a formal method to assess the resilience and inoperability of electric power systems using the results of contingency analysis. A model of disturbance propagation is proposed to avail their impact on resilience and inoperability indicators of Power Systems, and the contribution and cross impact from several market agents and actors during outages in the electric grid. The method is based on cascade disturbance propagation through the topology of the electric grid. Besides intrinsic forced and programmed outage rates, as well as protection reliability and dependability, time to manual or automatic reclosing are also modeled. Their joint contribution determines the final resilience and inoperability level of each grid node, and the fraction of responsibility of each agent. A working MatLab® implementation has been developed and documented. A simple case study will demonstrate its application.
Journal of Homeland Security and Emergency Management, 2018
Vulnerability to extended power outages stemming from grid collapse triggered by terrorism, technological accident, cyber attack or geomagnetic storms is understood to mean the widest possible spectrum of immediate and downstream consequences for our nations critical infrastructure. Regrettably few realistic plans are in place for dealing with this risk especially as it pertains to three primary energy systems of strategic significance to the United States-nuclear power, chemical manufacturing and natural gas supplies. The author argues that greater sustained attention is needed to upgrade the resilience of these systems, foster greater sharing of remedies among them to offset the worst effects of grid collapse which exceeds 15 consecutive calendar days and build collective avenues of enhanced risk mitigation against such scenarios.
The Vulnerability of the United States Electrical Power Grid
2019
The vulnerability of the United States electrical power grid, arguably perhaps the most critical among our nation’s critical infrastructure, has become an alarming and increasing reality. Various segments of our critical infrastructure, including transportation, telecommunications, public safety, the financial industry, and other utilities are dependent upon the electrical power grid. Conversely, the electrical power grid is dependent upon other critical infrastructure, namely oil, gas, and telecommunications to operate. Current threats to the United States electrical power grid include physical attacks, cyber-terrorism attacks, weather, natural disasters, electromagnetic pulse, and aging facilities. The Department of Homeland Security has noted that state actors who are a threat to the United States electrical power grid include Russia, China, Iran, and North Korea, while organized crime and jihadist extremist terrorists are among notable non-state actors (Angerholzer, Cilluffo, Mahaffee, & Vale, 2014). The purpose of this study will be to discuss the vulnerability of the United States electrical power grid and steps that can be taken to protect this portion of our critical infrastructure through a qualitative review of current and potential threats, current policies and shortcomings within these policies. Included in this discussion will be a summary of specific power failure incidents since 2001, an analysis of the risks to our electrical grid and recommendations to counter the threat to our electrical power grid.
Electric System Vulnerabilities: Lessons from Recent Blackouts and the Role of ICT
2005
Institute for the Protection and Security of the Citizen 2005 EUR21551EN Mission The mission of the Institute of the Protection and Security of the Citizen of the Joint Research Centre is to provide research-based, system-oriented support to EU policies so as to protect the citizen. The main application areas are cyber-security and the fight against fraud; natural, technological and economic risks; humanitarian security, nonproliferation and nuclear safeguards. The Institute will continue to maintain and develop its expertise in information, communication, space and engineering technologies in support of its mission. LEGAL NOTICE Neither the European Commission nor any person acting on behalf of the Commission is responsible for the use which may be made of the following information. Acknowledgement The author would like to thank Angelo Invernizzi, CESI, and Marc Wilikens, JRC, for the many insights and the advice given on early drafts of this report. He is also indebted to Giancarlo Manzoni, Enginet, and Marcelo Masera, JRC, for many comments and suggestions provided and for their careful review of the final draft. Special thanks to Marcel Bial, UCTE for his comments on the final draft.