Aspects Of System Reliability Research Articles

Using the flexibility of EPS as a means of improving the system reliability of power systems in modern conditions

Scientific research in the field of EPS flexibility has recently been intensified, and this flexibility is considered in a fairly broad setting. It is important to note that the issues of EPS flexibility are not new, but the term “flexibility” was not used to refer to this issue before, although all the main issues were considered within the framework of the topic of system reliability and development of EES, and the issue of continuity of modern research with previous scientific research and existing scientific results is important. Traditionally, one of the aspects of system reliability has been the power security of the EPS, which refers to the ability of the system to withstand sudden disturbances without unintended impacts on electricity consumers. At the same time, the analysis of power security was mainly performed only in the volume of the system-forming power gird of the EPS. For the power systems of the future, the importance of power security increases significantly, but as an analysis of the power security of the system-forming and distribution power grids together. For a number of years, the authors have been engaged in research in the field of mode reliability using the method of calculating EPS modes taking into account discrete and interval characteristics of mode parameters. This method allows us to study the properties of controllability of power systems of the future in the required problem statement.

Analysis of flexibility of power systems as the method for analyzing a power system security in modern conditions

In modern conditions, when there is a mass construction of small power plants based on renewable sources, the installation of power storage devices is gaining pace, consumers ' electrical installations are being modified, they are becoming adaptive and intelligent, there is a process of mass appearance of electric vehicles, and a revision of traditional provisions in the field of system reliability of power systems is required. Scientific research in the field of EPS flexibility has recently been intensified, and this flexibility is considered in a fairly broad setting. It is important to note that the issues of EPS flexibility are not new, but the term “flexibility” was not used to refer to this issue before, although all the main issues were considered within the framework of the topic of system reliability and development of EES, and the issue of continuity of modern research with previous scientific research and existing scientific results is important. Traditionally, one of the aspects of system reliability has been the power security of the EPS, which refers to the ability of the system to withstand sudden disturbances without unintended impacts on electricity consumers. At the same time, the analysis of power security was mainly performed only in the volume of the system-forming power gird of the EPS. For the power systems of the future, the importance of power security increases significantly, but as an analysis of the power security of the system-forming and distribution power grids together.

Investigating the Effect of System Reliability, Risk, and Role on Users' Emotions and Attitudes toward a Safety-Critical Drone System

ABSTRACTIn safety-critical systems, it is essential to communicate relevant information to facilitate decision-making, promote trust, and improve performance without overloading users. To explore the effect of system performance information on rational and emotional processing by users, we performed a between-subject experiment in which participants were asked to imagine themselves as a drone operator or system administrator in a high-, medium-, or low-risk scenario. Then, based on their imagined scenario and role, participants rated the relevance of four aspects of system reliability to decision-making with the system, as well as the expected intensity of the GREAT emotions. Results indicate that system performance information affected participants’ reasoning differently depending on risk level. Moreover, participants had different perspectives depending on their role in the system. Those in administrator roles indicated higher respect ratings for those with a similar role. These findings demonstrate that contextual risk and a user’s role can influence emotions and attitudes toward safety-critical computer systems.

Analysis of the security during power system expansion planning

Increasing the intelligent level of the EPS control systems, caused by the implementation of Smart technologies, changes the structure and the properties of EPS and increases the importance of system reliability analysis. System reliability analysis includes two components – for the balance and for the regime. On the one hand, there is a large number of studies to assess the reliability of the power system, which examines various aspects and methods of solving this problem. On the other hand, in Russia there is no generally accepted methodology with clear criteria that could be used for feasibility studies of various technical solutions taking into consideration system reliability aspects. In practice, the security analysis is limited by the calculations of power flows, static and dynamic stability for a number of forecast periods for the normal and repair circuits considering the most severe disturbances. The existing approach allows defining the requirements and adjusting emergency control systems, but does not allow evaluating and comparing solutions for power grid constructions. The authors propose a new method for power system reliability evaluation, which is suitable for planning development and operation of power systems. The method includes a general description of the algorithm which allows to compare various development scenarios, as well as to assess the reliability level of their implementation. In particular, the method allows to determine where it is needed only the relay protection and emergency control system development, and where it is necessary grid, protection and control development and reconstruction.

Operational Risk Metric for Dynamic Security Assessment of Renewable Generation

The objective of this paper is to explore the efficacy of applying risk-based security assessment (RBSA) to define reliability standards for electricity grids with high penetration of converter-interfaced generation. A novel approach to estimate the impact of transient instability is presented in this paper by modeling several important protection systems in the transient stability analysis. In addition, a probabilistic model is developed to capture the uncertainty of increased converter-interfaced renewable penetration. A synthetic test case is derived from a realistic power system to verify the proposed method. The simulation results show that RBSA not only provides significantly relaxed security limits, but also helps in identifying critical aspects of system reliability that are not possible using conventional deterministic methods.

Materials reliability issues with coaxial cable systems for the information superhighway

A frequently advocated design for theInformation Superhighwaythat will provide voice, video, and two-way digital communication for businesses and residences calls for transmission on optical fibers from the source (head end) to neighborhood nodes and coaxial cable for distribution from the neighborhood nodes to individual subscribers. Materials reliability challenges abound from the head end to the customer's premise. The maximum allowed service outage per customer is expected to be less than one hour per year. The fiber portion of the network, including lasers, amplifiers, lenses, and the fiber itself, carries two-way transmission to large neighborhoods. With one fiber serving hundreds of customers, cost/reliability tradeoffs emphasize reliability. At neighborhood nodes, where the network branches, coaxial components carry the signal to the street level, where each subscriber is served by at least one drop cable and one network interface unit. The volume of components is much higher. The challenge is to achieve high reliability at low cost. Indeed, one of the impediments to replacing coaxial distribution in the neighborhood with fiber is the difficulty of achieving low-cost, reliable packaging for lasers and other optical components, while maintaining reliability. Since covering all the many materials aspects of system reliability would fill an entire book, the important design considerations, materials issues, and test methods that bear on the reliability of hybrid fiber coaxial systems will be illustrated by reviewing several aspects of coaxial reliability. The intent is to illustrate the methods used to identify and prevent failure mechanisms and the information that must be assembled for making appropriate decisions on reliability/cost tradeoffs. While coaxial systems have been used for over 20 years to bring cable TV to homes across North America, the requirements for reliability and signal quality with these one-way analog rf systems are less demanding than those for two-way digital data transmission. Many of the reliability issues that could potentially degrade performance characteristics of coaxial cable systems are materials and environment related. This paper discusses these issues to the extent that they are currently understood, presents results from some ongoing research to improve our understanding of the potential materials/environment related causes of signal deterioration, describes some prevention strategies, and discusses some of the many materials challenges that remain.

A view of reliability and quality measurements for telecommunications systems

The authors present a customer (telephone company) oriented view of R&Q (reliability and quality) measurements for telecommunications systems based on Bellcore's experience and work in this area. On behalf of its clients, Bellcore has published its preliminary view of generic requirements for supplier quantification of several aspects of system reliability and quality measurement. These generic requirements are contained in Bellcore's 'Reliability and Quality Measurements for Telecommunications Systems (RQMS),' TA-TSY-000929 (1989). The measurements are applicable to network switching elements (local switch, tandem, signal transfer point, service control point, packet switch, adjunct, etc.), operations systems, and transparent systems. Their scope covers system, software, hardware, firmware, and product support, and they are directed toward the system test, first office application, and general availability system life-cycle stages. Issues covered by this document are discussed in some detail.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Management, systems and technology

The control and instrumentation of large modern power stations requires a systems approach involving modelling of dynamic and reliability aspects of systems and the exploitation of current technology developments. This has an impact on managerial principles and the organisation of design and project groups, particularly in the areas of control-computer-system software and hardware obsolescence

Book Reviews

Abstract Abstract Elementary Statistics, 3rd Edition, Janet T. Spence, John W. Cotton, Benton J. Underwood, Carl P. Duncan. Englewood Cliffs, N.J.: Prentice Hall, Inc., 1976. vi + 282 pp. $9.95. Reviewed by J. Frank Yates. Workbook (for) Elementary Statistics, 3rd Edition, Janet T. Spence. Englewood Cliffs, N.J.: Prentice-Hall, Inc., 1976. v + 153 pp. $4.95 paperback. Reviewed by J. Frank Yates. Statistical Theory, 3rd Edition, Bernard W. Lindgren. MacMillan Publishing Co., Inc., New York and Collier MacMillan Publishers, London, 1976. xiii + 614 pp. $14.95. Reviewed by Thomas J. Santner Concepts and Applications of Modern Decision Models, V.M. Rao Tummala and Richard C. Henshaw (eds.). East Lansing, Michigan: msu Business Studies, Michigan State University, 1976. x + 476 pp. $7.50, paperback. Reviewed by Robert L. Winkler Signal Processing, K.G. Beauchamp. London: George Allen & Unwin (1974). 547 pp. $32.50. Reviewed by Melvin J. HINICH Reliability and Fault Tree Analysis: Theoretical and Applied Aspects of System Reliability and Safety Assessment, R.E. Barlow, J.B. Fussel, and N.D. Singpurwalla (eds). Philadelphia: Society for Industrial and Applied Mathematics, 1975. xxxix + 927 pp. $29.50. Reviewed by Robert G. Easterling Probability Sampling of Hospitals and Patients, 2nd Edition, Irene Hess, Donald C. Riedel, and Thomas B. Fitzpatrick. Ann Arbor: Health Administration Press, 1975. xi + 204 pp. $9.75. Reviewed by Dallas W. Anderson An Econometric Model of the Life Insurance Sector of the U.S. Economy, J. David Cummins. Lexington, Massachusetts: Lexington Books, 1975. xii + 254 pp. $19.50. Reviewed by Mark Gersovitz Studies in Nonlinear Estimation, Stephen M. Goldfeld and Richard E. Quandt (eds.). Cambridge, Mass.: Ballinger Publishing Co., 1976. xiv + 278 pp. $20.00. Reviewed by V. Kerry Smith A Model of Output, Employment, Wages and Prices in the U.K., I.F. Pearce, P.K. Trivedi, C.T. Stromback, G.J. Anderson. New York: Cambridge University Press, 1976. 172 pp. $14.95. Reviewed by Ray C. Fair Introduction to Structural Equation Models, Otis Dudley Duncan. New York: Academic Press, 1975. ix + 180 pp. $12.95. Reviewed by Stephen E. Fienberg Path Analysis—a primer, C.C. Li. Pacific Grove, California: Boxwood Press, 1975. ix + 346 pp. $7.75 (paper), $10.00 (cloth). Reviewed by Robert C. Elston Variational Methods in Statistics, Jagdish S. Rustagi. New York: Academic Press, 1976. viii + 236 pp. $19.50. Reviewed by Geung Ho Kim Quantitative Analysis for Management Decisions, Marvin H. Agee, Robert E. Taylor, Paul E. Torgersen. Englewood Cliffs, N.J.: Prentice Hall, 1976. xxi + 384 pp. $13.50. Reviewed by Shimshon Kinory

Reliability and Fault Tree Analysis: Theoretical and Applied Aspects of System Reliability and Safety Assessment.

Reliability and Fault Tree Analysis: Theoretical and Applied Aspects of System Reliability and Safety Assessment.

Electronic system reliability—an American viewpoint

In the first part of this paper the economic aspects of system reliability are explored. The concept of the ‘adequate system’ is introduced, which system is defined as the lowest total-cost system that will perform as required. The relation of component-part cost to failure-rate levels is investigated, and the reactions of component performance upon design of an adequate system are examined in terms of the economic factors involved. A typical system is used to illustrate the points developed. Further, the number of systems needed to perform a given mission are considered in terms of annual cost and reliability levels of an individual system.The second part of the paper is concerned with the appraisal of the reliability of a system. This appraisal begins as early as possible in system evolution and makes use of estimation procedures which draw upon prior knowledge. Various assumptions which enter into such estimation methods are examined. It is pointed out that reliability estimates derived analytically must be verified by suitable tests of models at appropriate stages in the development of the system. The value of failure data obtained during the course of system development, manufacture and use in establishing levels of system reliability is emphasised.The final part of the paper deals with the effects of operating environment upon system reliability. The necessity of knowing the environment, and of conducting tests on models to evaluate its effects, is stressed. Two examples are given to illustrate some of the factors associated with environmental testing. One relates to the electrical performance of nickel-cadmium cells under space-simulation conditions; the other to the mechanical response of a structure under missile-flight environment.Broadly, the point of view taken is that electronic-system reliability is a synthesis of many related and interacting factors. Throughout the evolution of system design these factors should be most carefully balanced so that the ultimate product will perform at a level of reliability which is the optimum for the time, effort and money expended.