Impact Assessment of Hypothesized Cyberattacks on Interconnected Bulk Power Systems

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

Utilisation of transformer condition monitoring data

Electricity grids are getting older and demand of electricity is rising. The critical com-ponents in electricity transmission systems should be monitored for assessing the need for maintenance. The electricity grid works more reliable when the condition infor-mation of important components are available continuously and thus larger catastrophic failures are preventable. Transformers are one of the critical components in electricity transmission. It is im-portant that they operate continuously. Transformers are reliable and long life compo-nents but the older the transformer is, the more sensitive it is about to fail. Condition monitoring provides improved data on the condition of transformer. With on-line condi-tion monitoring it is possible to detect developing failures and then a corrective action can be made in time. This study focuses on the utilization of transformer condition monitoring system in tra-ditional grid and in upcoming smart grid. The aim is to find out, where the condition monitoring data is needed in electricity transmission and distribution system manage-ment and how it is possible to carry the information to right place. This thesis introduces first the basics of a power system, the construction of a trans-former, transformer condition monitoring methods and condition monitoring data pro-cess. After that the management of a power system within traditional and smart grid is analyzed. The asset management process of both type power systems is explored through case study of transformer failure situations. In traditional power system the transformer maintenance bases mostly on time scheduled inspections. In smart grid the management is all time aware on the condition information of transformers which al-lows using of better fault prevention strategies.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

A Wide-area Analysis of Shifts in Electric Power System Generation Profiles and High-impact Event Scenarios

Often cited as the largest machine in the world, the electric power grid is a complex system, integral to modern life. Continuous technology advancements over the past hundred years have delivered improvements to both the system itself, e.g., wide-area management systems (WAMS), as well as modeling capabilities in order to better understand how that system functions. Phenomena that could once be simulated only in small, localized settings can now be studied from a wide-area perspective. Chapter 1 briefly introduces the three major U.S. electric interconnections along with wide-area power system analysis tools and the benchmarked models used in this work. It also puts forward two topics that wide-area modeling must address: the effect of generation portfolio changes on dynamic system response and the assessment and hardening of the grid against high-impact, interconnection-wide events. The first topic is investigated in Chapter 2 and Chapter 3. Specifically, Chapter 2 examines dynamic response repercussions of the recent shift from coal-fired generation plants to natural gas turbines. Chapter 3 extends this discussion to the increase in low-inertia renewable sources. Modeling and analysis of wide-area events in line with the second topic, including extreme weather phenomena, solar storms, and physical attacks, as well as methodologies to harden the grid, are investigated in the remainder of this work. Chapter 4 begins with an example of modeling geomagnetically induced current (GIC) effects while Chapter 5 discusses high-altitude electromagnetic pulse (HEMP) components and impacts. Chapter 6, guided by the 2015 Fixing America’s Surface Transportation (FAST) Act, extends the scope of these scenarios and presents a methodology to find the most critical elements for any given system and determine the minimum required spare large power transformer (LPT) reserve that should be available. Conclusions and potential future research directions are presented in Chapter 7

Modernization and Rationale of Parameters Of Transformer Substation «Zhulyany»

This paper deals with the modernization of transformer substations and their equipment. The types of high-voltage switches are analyzed, the possibilities of improvement are revealed and the changes to the design of the air switch are proposed, which will allow to increase its speed and reliability of operation

Supporting group maintenance through prognostics-enhanced dynamic dependability prediction

Condition-based maintenance strategies adapt maintenance planning through the integration of online condition monitoring of assets. The accuracy and cost-effectiveness of these strategies can be improved by integrating prognostics predictions and grouping maintenance actions respectively. In complex industrial systems, however, effective condition-based maintenance is intricate. Such systems are comprised of repairable assets which can fail in different ways, with various effects, and typically governed by dynamics which include time-dependent and conditional events. In this context, system reliability prediction is complex and effective maintenance planning is virtually impossible prior to system deployment and hard even in the case of condition-based maintenance. Addressing these issues, this paper presents an online system maintenance method that takes into account the system dynamics. The method employs an online predictive diagnosis algorithm to distinguish between critical and non-critical assets. A prognostics-updated method for predicting the system health is then employed to yield well-informed, more accurate, condition-based suggestions for the maintenance of critical assets and for the group-based reactive repair of non-critical assets. The cost-effectiveness of the approach is discussed in a case study from the power industry

Condition monitoring of power transformer as part of power plant maintenance process

Power transformer is one of the most critical components for electrical network in power plants. This means that dependability has a big role. At the moment end users allocate resources to power transformer maintenance. Resources for on-line condition monitoring on the other hand are not very significant. Reason for this is that transformers are reliable and long life components. However, failure costs might be very significant and online monitoring is justified from that point of view. This thesis focuses on power transformer online condition monitoring. The goal is to find cost-effective and integrated solution which provides good-enough transformer monitoring. The subject has been studied quite a lot which tells about increasing interest towards the subject and might indicate possible markets for transformer monitoring services. In the beginning research will focus on describing maintenance and condition monitoring related terms. Also goals are defined for different stakeholders applying the Delphi method. The middle part of the work focus on power transformer structure, fault statistics, condition monitoring methods and measurement devices. Also possibilities of condition monitoring are covered. Research results are divided into two different categories. First part of the results will be related to requirements defined for power transformer condition monitoring. Results include requirements for three different ranges of transformer monitoring. Second part of the results contains a specification for pilot project to test power transformer condition monitoring methods and devices.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Power Grid Recovery after Natural Hazard Impact

Natural hazards can affect the electricity supply and result in power outages which can trigger accidents, bring economic activity to a halt and hinder emergency response until electricity supply is restored to critical services. This study analyzes the impact of earthquakes, space weather and floods on the power grid recovery time. For this purpose, forensic analysis of the performance of the power grid during 16 earthquakes, 15 space weather events and 20 floods was carried out. The study concluded that different natural hazards affect the power grid in different ways. Earthquakes cause inertial damage to heavy equipment and brittle items, and ground failure and soil liquefaction can be devastating to electric infrastructure assets. Recovery time is driven by the balance of repairs and capabilities. Poor access to damaged facilities, due to landslides or traffic congestion, can also delay repairs. In this study, recovery time ranged from a few hours to months, but more frequently from 1 to 4 days. Floods are commonly associated with power outages. Erosion due to the floodwaters and landslides triggered by floods undermine the foundations of transmission towers. Serious, and often explosive, damage may occur when electrified equipment comes in contact with water, while moisture and dirt intrusion require time-consuming repairs of inundated equipment. Recovery time was driven by the number of needed repairs, and site access, as repairs cannot start until floodwaters have receded. In this study, power was back online from 24 hours up to 3 weeks after the flood. However, longer recovery times (up to 5 weeks) were associated with floods spawned by hurricanes and storms. Space weather affects transmission and generation equipment through geomagnetically induced currents (GICs). In contrast to earthquakes and floods, GICs have the potential to impact the entire transmission network. Delayed effects and the potential for system-wide impact were the main drivers of recovery time in this study. When damage is limited to tripping of protective devices, restoration time is less than 24 hours. However, repairs of damaged equipment may take up to several months. The study concludes with a number of recommendations related to policy, hazard mitigation and emergency management to reduce the risks of natural hazards to electric infrastructure and to improve crisis management in the aftermath of a natural disaster.JRC.E.2-Technology Innovation in Securit

Time domain analysis of switching transient fields in high voltage substations

Switching operations of circuit breakers and disconnect switches generate transient currents propagating along the substation busbars. At the moment of switching, the busbars temporarily acts as antennae radiating transient electromagnetic fields within the substations. The radiated fields may interfere and disrupt normal operations of electronic equipment used within the substation for measurement, control and communication purposes. Hence there is the need to fully characterise the substation electromagnetic environment as early as the design stage of substation planning and operation to ensure safe operations of the electronic equipment. This paper deals with the computation of transient electromagnetic fields due to switching within a high voltage air-insulated substation (AIS) using the finite difference time domain (FDTD) metho