scholarly journals Impact of geomagnetic disturbances on power transformers: risk assessment of extreme events and data availability

2021 ◽  
Author(s):  
Wadih Naim ◽  
Patrik Hilber ◽  
Ebrahim Shayesteh
Keyword(s):  
Risk Assessment ◽  
Early Warning ◽  
Asset Management ◽  
Data Availability ◽  
Power Transformers ◽  
Load Management ◽  
Event Tree ◽  
Geomagnetically Induced Currents ◽  
Geomagnetic Disturbances ◽  
The Impact

AbstractCertain rare events can have a drastic impact on power systems. Such events are generally known as high-impact low-probability (HILP) events. It is challenging to predict the occurrence of a HILP event mainly due to lack of data or sparsity and scarcity of data points. Yet, it is essential to implement an evidence-driven asset management strategy. In this paper, event tree analysis is used to assess the risk of power transformer failure due to a geomagnetically induced currents (GIC). Those currents are caused by geomagnetic disturbances in Earth’s magnetic field due to solar activity. To assess the impact on power transformers, an understanding of the mechanism and sequence of sub-events that lead to failure is required to be able to construct an event tree. Based on the constructed event tree, mitigation actions can be derived. GIC blockers or reducers can be used. However, that would require extensive installation and maintenance efforts, and the impact on system reliability has to be studied. Also, such technology is still in its infancy and needs extensive validation. A suggested alternative is to combine early warning data from solar observatories with a load management plan to keep transformers below their rated operation point such that a DC offset due to GIC would not cause magnetic core saturation and overheating. Load management and the risk of early warning false positives can incur a negative effect on reliability. Nevertheless, the risk assessment performed in this paper show that incorporating load management in asset planning is a viable measure that would offset the probability of catastrophic failure.

Integration of Degradation Models Into Generation Risk Assessment (GRA): Challenges and Modeling Approaches

2009 ◽  
Author(s):  
Mikko I. Jyrkama ◽  
Mahesh D. Pandey ◽  
Stephen M. Hess
Keyword(s):  
Risk Assessment ◽  
Net Present Value ◽  
Fault Tree ◽  
Event Tree ◽  
Reliability Models ◽  
Degradation Models ◽  
Joint Contribution ◽  
The Impact ◽  
Tree Approach ◽  
Over Time

The main objective of generation risk assessment (GRA) is to assess the impact of equipment unavailability and failures on the ability of the plant to produce power over time. The system reliability models employed for this purpose are based on the standard fault tree /event tree approach, which assumes failure rates to be constant. However, this ignores the impact of aging degradation and results in static estimates of expected generation loss. Component and equipment degradation not only increases the probability of failure over time, but also contributes to generation risk through increased unavailability and costs arising from greater requirement for inspection and replacement of degraded components. This paper discusses some of the key challenges associated with integrating the results of component degradation models into GRA. Because many analytical and simulation methods are subject to limitations, the methodology and modeling approach proposed in this work builds on the current GRA practice using the fault tree approach. The modeling of component degradation can be done separately at the fault tree cut set level, assuming the cut sets are independent and the component unavailabilities are relatively small. In order to capture the joint contribution of equipment failure and unavailability to generation risk, new risk-based importance measures are also developed using the concept of net present value (NPV).

Integration of Degradation Models Into Generation Risk Assessment: Challenges and Modeling Approaches

2010 ◽  
Vol 132 (10) ◽  
Author(s):  
Mikko I. Jyrkama ◽  
Mahesh D. Pandey ◽  
Stephen M. Hess
Keyword(s):  
Risk Assessment ◽  
Net Present Value ◽  
Fault Tree ◽  
Event Tree ◽  
Reliability Models ◽  
Degradation Models ◽  
Joint Contribution ◽  
The Impact ◽  
Tree Approach ◽  
Over Time

The main objective of generation risk assessment (GRA) is to assess the impact of equipment unavailability and failures on the ability of the plant to produce power over time. The system reliability models employed for this purpose are based on the standard fault tree/event tree approach, which assumes failure rates to be constant. However, this ignores the impact of aging degradation and results in static estimates of expected generation loss. Component and equipment degradation not only increases the probability of failure over time, but also contributes to generation risk through increased unavailability and costs arising from greater requirement for inspection and replacement of degraded components. This paper discusses some of the key challenges associated with integrating the results of component degradation models into GRA. Because many analytical and simulation methods are subject to limitations, the methodology and modeling approach proposed in this work builds on the current GRA practice using the fault tree approach. The modeling of component degradation can be done separately at the fault tree cut set level, assuming the cut sets are independent and the component unavailabilities are relatively small. In order to capture the joint contribution of equipment failure and unavailability to generation risk, new risk-based importance measures are also developed using the concept of net present value.

Designing Risk Qualitative Assessment on Fiber Optic Instalation Project in Indonesia

2018 ◽  
Vol 2 (01) ◽  
Author(s):  
Devi Pratami
Keyword(s):  
Risk Assessment ◽  
Risk Analysis ◽  
Fiber Optic ◽  
Qualitative Assessment ◽  
Quality And Safety ◽  
Project Implementation ◽  
Cost Impact ◽  
Implementation Assessment ◽  
The Impact ◽  
Impact Cost

A project always has risks that can lead to project failure. In the project, a risk analysis is required to provide an evaluation for the project to proceed as planned. In the event of inadequate planning and ineffective control, it will result in irregularities identified as a risk to the project. This study aims to analyze the qualitative risk on Fiber Optic Installaion project in Sukabumi, West Java, Indonesia. In addition, risk assessment is undertaken on project implementation. Assessment of risk using the impact and probability to measure the impact of risk occurrence. The impacts are more detailed by classified by time impact, cost impact, quality impact, safety and security impact, proximity. The result is there are 36 risk that may occur and mostly risks are associaated by quality and safety&security impact.

Integration of cross asset risk assessment into road infrastructure asset management

2015 ◽  
Vol 105 (28) ◽  
pp. 1-7
Author(s):  
Alfred Weninger-Vycudil ◽  
Barbara Brozek ◽  
Roland Spielhofer ◽  
Chris Britton ◽  
Mark Oldfield
Keyword(s):  
Risk Assessment ◽  
Asset Management ◽  
Road Infrastructure ◽  
Asset Risk ◽  
Infrastructure Asset Management

A MODELING SYSTEM FOR CLIMATE CHANGE RISK ASSESSMENT, MANAGEMENT AND HEDGING IN COASTAL AREAS

2017 ◽  
Author(s):  
Sergei Soldatenko ◽  
Sergei Soldatenko ◽  
Genrikh Alekseev ◽  
Genrikh Alekseev ◽  
Alexander Danilov ◽  
...  
Keyword(s):  
Climate Change ◽  
Risk Assessment ◽  
Coastal Areas ◽  
Mitigation Strategies ◽  
System Structure ◽  
The Arctic ◽  
Risk Modeling ◽  
Wide Range ◽  
Adverse Weather ◽  
The Impact

Every aspect of human operations faces a wide range of risks, some of which can cause serious consequences. By the start of 21st century, mankind has recognized a new class of risks posed by climate change. It is obvious, that the global climate is changing, and will continue to change, in ways that affect the planning and day to day operations of businesses, government agencies and other organizations and institutions. The manifestations of climate change include but not limited to rising sea levels, increasing temperature, flooding, melting polar sea ice, adverse weather events (e.g. heatwaves, drought, and storms) and a rise in related problems (e.g. health and environmental). Assessing and managing climate risks represent one of the most challenging issues of today and for the future. The purpose of the risk modeling system discussed in this paper is to provide a framework and methodology to quantify risks caused by climate change, to facilitate estimates of the impact of climate change on various spheres of human activities and to compare eventual adaptation and risk mitigation strategies. The system integrates both physical climate system and economic models together with knowledge-based subsystem, which can help support proactive risk management. System structure and its main components are considered. Special attention is paid to climate risk assessment, management and hedging in the Arctic coastal areas.

Financial Risks of the Bank: Assessment and Mechanism of Neutralization

2020 ◽  
Vol 22 (1) ◽  
pp. 6-12
Author(s):  
Nelia Volkova ◽  
◽  
Alina Mukhina ◽  
Keyword(s):  
Risk Assessment ◽  
Financial Stability ◽  
Financial Risk ◽  
Stable Operation ◽  
Financial Risks ◽  
Negative Consequences ◽  
Conceptual Approach ◽  
Relevant Today ◽  
Banking Institution ◽  
The Impact

Abstract. Introduction. The issue of financial risk management of commercial banks is quite relevant today, because the activity of banks is the most risky of all. The presence of risks in banking can lead to unexpected losses, namely the loss of own resources. That’s why for the stable operation of the bank without loss the priority is to assess the financial risks, which is the basis for their further neutralization. Purpose. The purpose of the article is to develop conceptual provisions for assessment financial risks and justifying the need to neutralize them. Results. The article analyzes the impact of risks on the financial stability of a banking institution. The main methods of bank risk assessment are considered. All these include the statistical method, the analytical method, the expert method, the analogue method and the combined method. The necessity of neutralization of financial risks in order to avoid negative consequences is substantiated. Also the methods of bank risks neutralization are considered. It should be noted that these methods of neutralization can not only be used, but also supplement the list with new methods must be done, which in the future will protect the bank from the influence of undesirable factors. A conceptual approach to the assessment and neutralization of financial risks is proposed. This conceptual approach aims to ensure effective assessment of the level of risk with their subsequent neutralization Conclusions. Use of a conceptual approach will allow an effective risk assessment and decision-making to avoid or accept risk. Thanks to using this approach, the banking institution will be able to react swiftly to the presence of financial risks and to prevent the occurrence of negative consequences, which may lead to a violation of the financial stability of the bank.

Implementasi Probability Impact Matriks (PIM) Untuk Mengidentifikasi Kemungkinan dan Dampak Risiko Proyek

2017 ◽  
Vol 8 (1) ◽  
pp. 43-47
Author(s):  
Sufa'atin Sufa'atin
Keyword(s):  
Risk Assessment ◽  
Cumulative Effect ◽  
Project Risk ◽  
Project Construction ◽  
Index Terms ◽  
Project Objectives ◽  
The Impact

One of the obstacles in project construction is that the project is experiencing delays. The delay is influenced by several factors including the absence of risk recording, the unavoidability of the opportunities and the impact of risks that arise in the project and its handling, and the neglected risks that may disrupt the project. Project risk is the cumulative effect of an uncertain event opportunity, which affects the project objectives. Several methods can be used to handle the occurrence of project risk, one of the methods used to perform a risk assessment is the Probability Impact Matrix (PIM). PIM is a method that can be used to analyze risk qualitatively based on probability and its impact. By using the PIM method, some of the opportunities and impacts of risks that may arise in the project can be identified. In addition, the PIM method can minimize the risks that arise in the project and quickly resolve the risks. Index Terms— Project, Risk, PIM, Possibility, Impact

IMPACT ASSESSMENT ON STORM SURGE RISKS TO CONTAINERS CONSIDERING GLOBAL WARMING

2017 ◽  
Author(s):  
Rikito Hisamatsu ◽  
Rikito Hisamatsu ◽  
Kei Horie ◽  
Kei Horie
Keyword(s):  
Risk Assessment ◽  
Global Warming ◽  
Storm Surge ◽  
Storm Surges ◽  
Assessment Tools ◽  
Inundation Depth ◽  
Risk Assessment Tools ◽  
Risk Maps ◽  
The Impact ◽  
Vulnerability Functions

Container yards tend to be located along waterfronts that are exposed to high risk of storm surges. However, risk assessment tools such as vulnerability functions and risk maps for containers have not been sufficiently developed. In addition, damage due to storm surges is expected to increase owing to global warming. This paper aims to assess storm surge impact due to global warming for containers located at three major bays in Japan. First, we developed vulnerability functions for containers against storm surges using an engineering approach. Second, we simulated storm surges at three major bays using the SuWAT model and taking global warming into account. Finally, we developed storm surge risk maps for containers based on current and future situations using the vulnerability function and simulated inundation depth. As a result, we revealed the impact of global warming on storm surge risks for containers quantitatively.

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