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Matti Lehtonen

Bio: Matti Lehtonen is an academic researcher from Aalto University. The author has contributed to research in topics: Fault (power engineering) & Electric power system. The author has an hindex of 40, co-authored 694 publications receiving 8559 citations. Previous affiliations of Matti Lehtonen include Razi University & New York University.


Papers
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Journal ArticleDOI
TL;DR: A new framework to incorporate the reliability of distribution network into designing the optimal bidding strategy of a TVPP in day-ahead energy market is presented.
Abstract: Technical virtual power plant (TVPP) aggregates distributed energy resources in order to trade in wholesale electricity market while taking operational constraints of network into account and offering services to distribution system operator This article presents a new framework to incorporate the reliability of distribution network into designing the optimal bidding strategy of a TVPP in day-ahead energy market In the proposed framework, the TVPP determines the multisteps biddings as pairs of power and price aiming at maximizing its profit in market while minimizing the outage costs due to contingency occurrences The model is formulated as a bilevel optimization problem in which the upper level maximizes the TVPP's profit regarding network reliability and the lower level clears the market from ISO's viewpoint Using Karush–Kuhn–Tucker optimality conditions and strong duality theory, the model is converted to a mixed integer linear programming optimization problem The proposed framework is implemented on the Roy Billinton test system to illustrate the effectiveness of the model

18 citations

Proceedings ArticleDOI
06 Jun 2016
TL;DR: In this article, a review summarizes the academic work done in the fields of worth of electric power reliability and customer interruption costs assessment techniques from the year 1990 to 2015, and concludes that there has been an increased attention by the researchers in the field of economic worth of electricity service reliability.
Abstract: As the society gets more dependent on continuous electricity supply, the impacts of disruptions in the service yield significant economic losses for all customer segments. There is crucial need for understanding the worth of reliability improvements in the power systems for planning purposes of the transmission and distribution systems. That is why, there has been an increased attention by the researchers in the field of economic worth of electricity service reliability. This review summarizes the academic work done in the fields of worth of electric power reliability and customer interruption costs assessment techniques from the year 1990 to 2015.

18 citations

Journal ArticleDOI
TL;DR: In this article, the authors proposed a fault-location algorithm based on the pure fault circuit with the initial condition of the earth fault using the measurements at each lateral panel, which is applicable for earthed or unearthed networks with all possibilities of transformer connection and load taps.
Abstract: This study integrates earth fault location computation with fault management-control schemes for distribution networks. To realise this target, a panel substation is located at the lateral outlet. The faulted section is identified precisely via a fault-location algorithm. Then, isolating the faulted section is accomplished through control signals between the lateral-panel substation and the faulted section isolators. The service restoration is achieved by a direct communication between the lateral-panel substation and the feeder primary substation. The proposed fault-location algorithm is based on the pure fault circuit with the initial condition of the earth fault using the measurements at each lateral panel. For phase-to-ground fault, the initial condition is the series connection for the sequence networks from the fault point. For phase-to-phase-to-ground fault, the initial condition is that the summation of the sequence currents at the fault point is equal to zero. The proposed fault-location algorithm is, therefore, suitable for equipping distribution systems with distributed generation. Moreover, it is applicable for earthed or unearthed networks with all possibilities of transformer connection and load taps. For investigation purposes, simulation tests are performed using the IEEE 33-bus automated feeder example. The simulation test results corroborated the efficacy of the proposed fault management system.

18 citations

Journal ArticleDOI
TL;DR: In this article, a reliability analysis of conventional isolated pulse width modulation DC-DC (IDC-DC) converters is presented, where the impact of duty cycle, input voltage, output power, transformer turns ratio, components characteristics and time duration on the overall reliability performance of the DC converters are analyzed.
Abstract: This paper sets forth the reliability analysis of conventional isolated pulse width modulation DC-DC (IDC-DC) converters. The IDC-DC converters are categorized into isolated single-switch DC-DC (ISSDC-DC) or multiple-switch DC-DC (IMSDC-DC) converters. The proposed framework encompasses analyzing the impacts of duty cycle, input voltage, output power, transformer turns ratio, components characteristics and time duration on the overall reliability performance of the IDC-DC converters. The suggested reliability assessment is centered on Markov models characterized by taking into consideration all open and short circuit faults on the components in both continuous and discontinuous conduction modes. We further investigate the self-embedded fault tolerant capability of the IMSDC-DC converters under open circuit fault scenarios on the switches, diodes and blocking capacitors, where we offer new reliability analytics. Along with extensive analyses and comparisons, several experimental results are provided to verify the self-embedded fault tolerant capability of IMSDC-DC converters.

17 citations


Cited by
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Journal ArticleDOI

[...]

08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

Journal Article
TL;DR: This book by a teacher of statistics (as well as a consultant for "experimenters") is a comprehensive study of the philosophical background for the statistical design of experiment.
Abstract: THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

13,333 citations

Book
01 Jan 2009

8,216 citations

Book ChapterDOI
01 Jan 1982
TL;DR: In this article, the authors discuss leading problems linked to energy that the world is now confronting and propose some ideas concerning possible solutions, and conclude that it is necessary to pursue actively the development of coal, natural gas, and nuclear power.
Abstract: This chapter discusses leading problems linked to energy that the world is now confronting and to propose some ideas concerning possible solutions. Oil deserves special attention among all energy sources. Since the beginning of 1981, it has merely been continuing and enhancing the downward movement in consumption and prices caused by excessive rises, especially for light crudes such as those from Africa, and the slowing down of worldwide economic growth. Densely-populated oil-producing countries need to produce to live, to pay for their food and their equipment. If the economic growth of the industrialized countries were to be 4%, even if investment in the rational use of energy were pushed to the limit and the development of nonpetroleum energy sources were also pursued actively, it would be extremely difficult to prevent a sharp rise in prices. It is evident that it is absolutely necessary to pursue actively the development of coal, natural gas, and nuclear power if a physical shortage of energy is not to block economic growth.

2,283 citations