Recent Blackouts Research Articles

AC transmission expansion planning based on self‐organized criticality to mitigate the risk of cascading blackouts

AbstractThe secular increase of load causes the evolving power system to operate near the critical margins. In such attitudes, the probability of cascading line outages, as the major reason for recent blackouts, is much more than expected. As a result, an innovative approach for optimal AC transmission expansion planning (TEP) to minimize the risk of cascading blackouts is presented in this paper. The proposed multi‐objective AC‐TEP problem minimizes the expected energy not supplied due to the total load shedding imposed on the system to mitigate the risk of cascading line outages along with the total investment and operational costs of the new transmission lines planned to be optimally added to the system. This probabilistic procedure is based on self‐organized criticality and considers the actual aspects of the power system such as reactive power and voltage concerns in the planning stage. The obtained Pareto front set provides the opportunity for the planners to choose the most preferred solution. The proposed method is implemented and verified in the IEEE 118‐bus test system and compared with two types of TEP approaches. The first one is a previously reported version of this work which was a simplified DC model of the problem and the second one is the conventional AC‐TEP model. The obtained results show the benefits of the proposed AC model on the mitigation of cascading line outages in a more realistic framework, considering the impact of reactive power and voltage stability concerns.

Recent alcohol-induced blackouts among heavy drinking college students: A qualitative examination of intentions, willingness, and social context.

One-third to half of emerging adult drinkers report experiencing alcohol-induced blackouts in the past year, and blackouts increase the risk for negative consequences. Qualitative methods provide valuable tools for scientific inquiry, allowing for in-depth understanding of lived experiences. The goal of the present study was to gain insight into emerging adults' recent blackout experiences. One hundred heavy drinking college students (age 18-20) completed a baseline survey, 28 days of ecological momentary assessment (EMA) of their alcohol use and consequences, and a follow-up interview. A subset of 37 (46% female, 13.5% Hispanic/Latinx, 54% non-Hispanic ethnicity/White race) endorsed a blackout (forgot what they did during or after drinking) and were interviewed regarding their recent blackout experience. A semi-structured interview guide focused on several key questions regarding intentions and/or willingness to black out, how friends reacted to their blackout, and social norms for blacking out. A priori as well as emergent themes were generated from review of coded data. Qualitative themes included: blackouts are often unintentional, heavy drinking young adults express willingness to black out, friends react in a variety of ways to blackouts, and blackouts are perceived as common and acceptable. Data provide insight into the phenomenology of blackouts among college students, revealing that although college students may not intend to, they are often willing to black out. Future qualitative studies on blackouts among non-college-attending emerging adults are warranted. Such work can inform theory and future survey studies to better understand this high-risk behavior. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Electricity Generation from Hydro, Wind, Solar and the Environment

Human actions such as electricity generation are contributory causes of climate change. In a quest to reduce the emission of greenhouse gases associated with electricity generation from fossil fuels, the world is turning to renewables. Renewable sources, however, also do have an impact on the environment. Likewise, renewable electricity generation is also dependent on the climate. Hydro, Wind, and Solar are the popular renewable energy sources for the generation of electricity. This work reviews the impact of these renewables in electricity generation on the environment. It also considers the effect of climate change on its use. The construction of renewable electricity generating plants leads to habitat disruptions and can also cause fatalities. Climate change weighs an enormous impact on the performance of renewable electricity generating plants. The recent blackout experienced in Texas as a result of the cold weather is a good example. The end of extreme weather conditions is not yet, and the need to start preparing to prevent a blackout re-occurrence. A possible solution for sustainable renewable electricity generation in extreme weather conditions lies in synthetic fuel availability.

A Novel Technique to Detect False Data Injection Attacks on Phasor Measurement Units.

The power industry is in the process of grid modernization with the introduction of phasor measurement units (PMUs), advanced metering infrastructure (AMI), and other technologies. Although these technologies enable more reliable and efficient operation, the risk of cyber threats has increased, as evidenced by the recent blackouts in Ukraine and New York. One of these threats is false data injection attacks (FDIAs). Most of the FDIA literature focuses on the vulnerability of DC estimators and AC estimators to such attacks. This paper investigates FDIAs for PMU-based state estimation, where the PMUs are comparable. Several states can be manipulated by compromising one PMU through the channels of that PMU. A Phase Locking Value (PLV) technique was developed to detect FDIAs. The proposed approach is tested on the IEEE 14-bus and the IEEE 30-bus test systems under different scenarios using a Monte Carlo simulation where the PLV demonstrated an efficient performance.

Examining the relationship between social norms, alcohol-induced blackouts, and intentions to blackout among college students.

Alcohol-induced blackouts are a common high-risk outcome of heavy episodic drinking and are considered a marker of problematic alcohol consumption. One's estimates of the prevalence and peer approval of heavy episodic drinking (i.e., social norm perception, descriptive and injunctive norms, respectively) strongly relate to high-risk alcohol consumption. However, it is unknown whether the intention to blackout and the occurrence of alcohol-induced blackouts also associates with these estimates. Therefore, the purpose of this paper is to explore the relation between participants' social norm perception and alcohol-induced blackout intentions and recent blackout history. A total of 4430 participants completed an online survey with an average age of 19.97 (SD=1.70) years. A series of ANOVAs and a structural equation model examined the relation between social norm perception, intention to blackout, and recent blackout history. In the structural equation model, the social norm variables (descriptive and injunctive norms) were associated with higher levels of blackout intentions and recent blackout history. The global fit indices suggest that the data fit the model, χ2 (n=4248, 442)=7755.90, p<.001, CFI=.96, TLI=.96, RMSEA=.06 (CI90 .061-.064). Participants with a higher likelihood of having a past 30-day history of alcohol-induced blackouts and higher blackout intentions believed that many of their peer groups approved of certain alcohol-related behaviors and that their peer groups drink frequently and drink higher quantities. Future interventions may assess the impact of adjusting social norms on both the intention to blackout and experiencing blackouts.

Review of the recent blackouts and the enlightenment

With the development of technology, the connection between the power system and the social economy has grown to a high level. To avoid the massive damage caused by power blackouts, in this study, several large-scale blackouts that happened around the world recently have been reviewed and analysed. First, the backgrounds, processes and causes of the blackouts are elaborately illustrated. The causes are summarised into some main points, and coping strategy for each point is discussed. Finally, some enlightenments are concluded to cope with the blackouts and guarantee the security of the power system.

Flexible Resources Planning for Bulk Energy System With High Penetration of Renewable Energy Based on Bash Game

The recent blackout in UK indicates that the adequacy of flexible resources is a significant factor for the stability of bulk energy system under the high integration of renewable energy. This paper proposes a planning model that incorporates various flexible resources into uncertain energy system and hence optimizes the unites' capacity and dispatch schedule. Based on Bash Game theory, the optimization capacity and dispatch schedule problems are formulated accordingly. Without setting the capacity configuration variable, the model initiatively considers the stochastic nature of RE at the planning stage. To simplify the complexity of the planning model, the problem is relaxation decoupled into two convex sub-issues, which achieves dramatic improvements in solution time. The novel model has been simulated both under IEEE-39 system and IEEE-118 system and hence the model's performance has been tested. Under the proposed model, the energy system can operate in a secure, economic and optimal state. Results demonstrate the effectiveness of the proposed method in applying to the future energy system.

Probabilistic Study of Undervoltage Load Shedding Scheme to Mitigate the Impact of Protection System Hidden Failures

The investigations on recent blackouts have disclosed that one of the main reasons for cascaded tripping of protection systems is hidden failures (HFs). This involves an in-depth study of the different modes of HF in protection systems to assess their impact on cascading events in a power grid. This paper portrays a detailed study on the modeling of different HF modes and proposes a supervised undervoltage load-shedding scheme to further reduce the likelihood of cascading events caused by HFs. The proposed methodology uses two different probabilistic models of HFs to assess HFs’ impact on cascading events. The proposed methodology is validated through numerous case studies on the IEEE 57-bus network. It is also observed that inclusion of self-monitoring and control features in digital relays significantly reduces the risk of wide-area blackouts. The methodology can be effectively adopted for planning, inspection, and repair of the protection system and the maintenance of it where investment guarantees its reliability.

Synchrophasor‐based system integrity protection scheme for an ultra‐mega‐power project in India

System Integrity Protection Scheme (SIPS) aids the normal protection scheme in case of certain special contingencies like tripping of important corridors/flow gates etc. to mitigate the voltage or angular instability, load generation imbalance and finally large-scale cascading catastrophes. A recent blackout incident in an ultra-mega-power project (UMPP) in India has motivated the authors to ponder upon a SIPS as a solution. As part of designing the SIPS, an efficient solution is formulated using synchrophasors for a well-known issue nonetheless an issue which still disturbs the Indian power system network with blackouts – i.e. unintended distance relay operation in the event of power swing. Here, real-time voltage and current phasors and the angular separation between the buses connecting faulted line, acquired by phasor measurement unit is utilised to derive a differential power coefficient (DPC). This study proposes a modified logic scheme for blocking/de-blocking of distance relays i.e. change the existing scheme with ‘block all zones except Zone-1’ to ‘block all zones on power swing detection’. Rate of change of DPC is derived here which aids in differentiating stable and unstable power swings. A special protection scheme is finally formulated based on the modified logic.

A Real-Time Controlled Islanding and Restoration Scheme Based on Estimated States

Power system operators are facing major challenges today to keep the system operating at the admissible limits. Recent blackouts demonstrated the need for a systematic study and design of a comprehensive system control strategy. Intentional controlled islanding (ICI) has been proposed as an effective corrective control action of final resort to save the system from a partial or a complete blackout. ICI limits the occurrence and consequences of blackouts by splitting the power system into a group of smaller, stable, and sustainable subsystems, also called islands. After a controlled system separation, power system operators should resynchronize and reconnect each island to restore the system. In this sense, real-time knowledge of the operating condition of the islands is required. In this paper, a real-time ICI and restoration scheme is proposed. The proposed scheme consists of an ICI algorithm that finds islanding solutions with minimal power-flow disruption while considering power system restoration constraints (e.g., blackstart availability, sufficient generation capacity, and observability), a real-time state estimator that monitors the system before and after the islanding, and a restoration process. The proposed ICI and restoration scheme is tested using the dynamic IEEE 39- and 118-bus test systems.

Synchro‐phasors Assisted Back‐up Protection of Transmission Line

Certain power system situations force protection schemes to mal-operate. Such mal-operations associated with back-up protection (BP) schemes might worsen the situation by initiating the cascading effect, damaging critical elements such as generation units, transformers etc. of the power system, or leading to complete collapse of the power system. To adapt to such a network structure, the relays which are going to participate in BP of transmission line have to evolve. Integration of protection systems, communication network, and computer technology has to be the approach for faster information sharing and decision making. Analysis of recent blackouts clearly shows the importance of advancement of wide-area measurement systems and adaptive nature of relaying. Synchro-phasors assisted BP scheme is proposed in this work, which helps the relays adapt according to the prevailing system situations and decisive action is taken considering security and dependability aspects of the relays.

DLR-supported overcurrent line protection for blackout prevention

Analysis of recent blackouts over the past decade has indicated overloads as being responsible for initiation and development of most large area failures. The overload occurrences have also been found to correspond especially with the overcurrent and distance protection, often causing their overfunction under allowable power system operating conditions. It is highly desired to improve the operation of protection relays for the sake of avoiding future blackout occurrences or at least lowering their scale. One of the possibilities to do so is an application of the Dynamic Line Rating algorithms into the standard overcurrent relay with the hope of ensuring safe relay behavior during overloads.The Dynamic Line Rating is usually proposed to be used for increasing the line transfer capacity by monitoring of the overhead conductors temperature and weather conditions. It is clear that one must also take into account the impact of DLR-operated line on the existing protection devices. It is required to adapt their decision-making algorithms to the new conditions, while satisfying arbitrarily established protection principles.This paper presents firstly chosen recent decade blackouts, highlighting the main causes of their formation and development process. Applicable solutions for overcurrent relay improvement are then proposed, which is followed by analyses of the new relay algorithms’ operation during allowable overloads and faults. The enhanced overcurrent relay solution introduced in this paper proved to be an efficient technique also for blackout prevention.

Power Grid Resilience [Scanning the Issue

Hurricane Sandy and other recent extreme weather events, which have caused significant service interruptions including power outages, have revealed that our power grid is not sufficiently planned and operated to be resilient to large-scale events. Power grid resilience is a generic term that covers many aspects of power grid planning and operation. A resilient power grid should be capable of executing preventive measures, mitigating the impact of extreme events, responding optimally by automated control procedures, reducing the time needed to restore service to consumers, and potentially leading to significant economic savings. In addition, due to the growing usage of information and communication technologies (ICT), power grids are being increasingly exposed to cyber attacks. The recent blackout in Ukraine serves as a good example to illustrate the severe consequence that cyber attacks on the power grid can entail. Extensive reports and media coverage indicate the urgency to improve our power grid resilience. Maintaining resilience of the power grid is crucial to our nation’s energy security and sustainability.

Blackouts among male and female youth seeking emergency department care

ABSTRACTBackground: Alcohol-related blackouts are a common consequence of heavy drinking, and these blackouts pose risk for injury and other adverse health outcomes. Objective: To examine the prevalence and correlates of blackouts among underage drinkers. Methods: Youth (ages 14–20) presenting to a suburban Emergency Department (ED) completed screening surveys. Among those reporting past-year alcohol consumption, we examined past 3-month blackouts in relation to: background characteristics (e.g., demographics, fraternity/sorority involvement), substance use, sexual risk behaviors and incapacitated sexual assault (unaware/unable to consent due to alcohol/drugs), forced sexual assault, positive depression screening, and reason for ED visit (injury vs. medical). Results: In total, 2,300 past-year drinkers participated: 58% female, 75% Caucasian, and mean age = 18.4. Regarding past 3-month blackouts, 72.7% reported none, 19.3% reported monthly or less, and 8% reported monthly or more. Multivariate cumulative logit regression indicated that blackout frequency was positively associated with: college involvement in Greek life, alcohol use severity, prescription drug misuse, marijuana, screening positive for depression, incapacitated sexual assault, and a gender by alcohol use severity interaction. Conclusion: With one-quarter of this clinical sample reporting recent blackouts, as well as the association between blackout frequency and health risk behaviors and other outcomes, findings underscore the need for programs focusing on substance use, depression, and preventing sexual assault. Interventions should also address poly-substance use and drinking motives. Although findings highlight how college students in Greek life may be at high risk for blackouts, many participants not in college also reported blackouts, suggesting that interventions in other settings are also needed.

Sex and Drugs and Starting School: Differences in Precollege Alcohol-Related Sexual Risk Taking by Gender and Recent Blackout Activity

Research has demonstrated a link between alcohol use and multiple forms of risky sexual behavior, particularly among college-age individuals. Studies have also linked heavy alcohol use to other problems, such as impaired consciousness resulting from an alcohol-induced blackout, which may impact sexual decision making. However, research has rarely examined sexual risk taking (SRT) in relation to blackouts, nor has it examined this construct during the precollege transition (i.e., the interval of time between high school graduation and college matriculation). This study examined the intersection between alcohol-involved SRT, blackouts, and gender in a sample of precollege individuals with prior alcohol use (N = 229; 54% male, 63% White). Results indicated that, despite drinking less per occasion, women reporting recent blackouts were at increased risk for experiencing unwanted, unsafe, and regretted sexual behaviors compared to men with recent blackouts and their peers with no recent blackouts. Women with recent blackouts also reported differences in alcohol expectancies that may increase their risk for experiencing negative consequences while drinking, including higher social expectancies and lower negative expectancies of danger. Future directions for research and implications for precollege interventions are discussed.

Improving the performance of power system protection using wide area monitoring systems

Wide area monitoring (WAM) offers many opportunities to improve the performance of power system protection. This paper presents some of these opportunities and the motivation for their development. This methods include monitoring the suitability of relay characteristics, supervisory control of backup protection, more adaptive and intelligent system protection and the creation of novel system integrity protection scheme. The speed of response required for primary protection means that the role WAM in enhancing protection is limited to backup and system protection. The opportunities offered by WAM for enhancing protection are attractive because of the emerging challenges faced by the modern power system protection. The increasingly variable operating conditions of power systems are making it ever more difficult to select relay characteristics that will be a suitable compromise for all loading conditions and contingencies. The maloperation of relays has contributed to the inception and evolution of 70 % of blackouts, thus the supervision of the backup protection may prove a valuable tool for preventing or limiting the scale of blackouts. The increasing interconnection and complexity of modern power systems has made them more vulnerable to wide area disturbances and this has contributed to several recent blackouts. The proper management of these wide area disturbances is beyond the scope of most of the existing protection and new, adaptive system integrity protection schemes are needed to protect power system security.

Risk-Based Power System Security Analysis Considering Cascading Outages

Successful development of smart grid demands strengthened system security and reliability, which requires effective security analysis in conducting system operation and expansion planning. Classical ${{N}} - 1$ criterion has been widely used to examine every creditable contingency through detailed computations in the past. The adequacy of such approach becomes doubtful in many recent blackouts where cascading outages are usually involved. This may be attributed to the increased complexities and nonlinearities involved in operating conditions and network structures in context of smart grid development. To address security threats, particularly from cascading outages, a new and efficient security analysis approach is proposed, which comprises cascading failure simulation module (CFSM) for postcontingency analysis and risk evaluation module (REM) based on a decorrelated neural network ensembles (DNNE) algorithm. This approach overcomes the drawbacks of high computational cost in classical $N\!\!-\!\!k$ -induced cascading contingency analysis. Case studies on two different IEEE test systems and a practical transmission system—Polish 2383-bus system have been conducted to demonstrate the effectiveness of the proposed approach for risk evaluation of cascading contingency.

Front Lines Against the Darkness: Enhancing the Resilience of the Electricity Grid Through Microgrid Facilities

power grids are supposed to be fault-tolerant, but you doubt the premise when you consider daily outages in more populated parts of the world and more recent brownouts and blackouts globally. Power engineers have been pushing forward the frontiers of power systems, and the hard-fought battle against the darkness is supposed to have been won, but the struggle is by no means over. Indeed, the electricity grid today is faced more intensely with challenging issues concerning cyber and physical system security. The recent blackout in Turkey on 31 March 2015, which knocked out the transportation infrastructure in major cities, causing massive traffic jams, is a testimony to this claim. It also shut down vital services to thousands of offices for several hours, inflicting business and social losses (see Figure 1). Although widespread blackouts are regarded as low-probability events, they carry immense socioeconomic costs. In such events, the burden of responsibility often lies with extreme weather events, cascading failures, or similar low-probability, high-impact incidents. According to a report from the White House Council of Economic Advisors, severe weather is the major cause of power grid outages in the United States. Meanwhile, it is estimated that weather-related power outages cost the American economy more than US$300 billion between 2003 and 2012. The report calls for increased investment to enhance the resilience of the power grid against rising incidences of extreme weather such as thunderstorms, hurricanes, and blizzards predicted by climate models.

Using temporal causal models to isolate failures in power system protection devices

Smart Electric Grids and their underlying generation, transmission and distribution systems are constantly exposed to dynamic environments resulting from varying power flows, both direction and magnitude, changing operational requirements and conditions, physical component degradation, and software failures. Maintaining reliability of the power grid even in the presence of faults is one of the top national priorities [1]. Recent blackouts and Hurricane Sandy in 2012 demonstrated the grid vulnerability and reasons to look at existing defense mechanisms more closely. State of the art relies on a network of protection devices that include relays to detect anomalies and circuit breakers to isolate parts of the system that include the faulty components. These local protection schemes operate in short timescales to arrest the fault propagation and protect the remaining system. While the protection devices can mask the fault effects locally, it is important to analyze the events in a global context to improve the decision making. Protection malfunction and its correlation with major blackouts require a careful rethinking of its system-wide effects [2], [3]. This problem is often compounded due to loss of information from relays or Remote Terminal Unit (RTU) failure in the field. Such hidden (unobservable) relay failures are hard to locate and may be responsible for cascades [3].

Fast Algorithms of Line Outage Distribution Factors with Cascading Failures

The prominent role of cascading outages in recent blackouts has created a need in security applications for evaluating line outage distribution factors (LODFs) under the multiple-line outages. Two fast algorithms of LODFs with multiple-line outages are proposed in this paper. In the first method, the double-line outage LODFs are expressed in terms of single-line outage LODFs, and it can be extended to N-k (k≥2) contingencies without any complex matrix operation through the recursive theory. In the second method, a computationally efficient expression of LODFs based on power transfer distribution factors (PTDFs) in pre-contingency network is presented. Numerical simulations are carried out on IEEE 14 and 118-bus test systems. The results show that both methods can effectively improve the computation speed of multiple-line outage LODFs.