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Performance efficiency analysis of electric power supply systems
Abstract
Predetermined by the need to increase effectiveness of electric power supply and electric power consumption, the interconnected problems of effectiveness of these processes were explored. The object of present study is effectiveness of operation of electric power systems and the subject of the study is the processes to increase their effectiveness. The problems are caused by energy-consuming technologies, unstable consumption of electricity and out-dated organization. On the one hand, it is the variable system of electric power consumption, on the other hand, the unstable system of electric power supply. It was established in the work that these systems could be balanced by their constant optimization. All operative factors of influence are established for this. Based on this, the processes of electric power consumption and supply are optimized with the help of the diagram of cause-effect interrelations. All factors, which influence effectiveness of electric power consumption and electric power supply, are represented by the Ishikawa Kaoru diagram and are divided into four groups: organizational, technical, technological and economic with their specific definition. It was followed by an analysis of their influence with separating 7-9 basic factors in each group. The establishment of the optimum variant of EPS and EPC is classically reduced to determining characteristic of distributive function, strategy and modes at minimization of effectiveness indicators. It is simpler to establish the optimum structure of electric power supply and electric power consumption, using, to describe them, directed graphs, the vertices of which correspond to the elements of the structure, and arcs correspond to relationships between them. For further mathematical processing, this directed graph is described by the system of matrix equations and the task is reduced to the search for minimum or maximum paths in the directed graph. © N. Grigorieva, L. Dobrovolskaya, D. Sobchuk, V. Shabaykovich, M. Romaniuk, 2017.
... Gaiffe et al. 7 have established a fuzzy searching allocated index as the very good about funneled water supply service facility inside a minimum income town surrounding by a complex. Grigorieva et al. 8 have studied solar power supply patterns during performance adequacy analysis. ...
In this paper, we compute the total cost optimization for power
supply queuing model with infinite servers in fuzzy environment. The objective of this research paper is to compute the optimal total-cost by establishing the total optimal cost function for the model system in fuzzy environment so as to present more realistic results of the queuing model to yeild explicit result. Finally, sensitivity analysis of the model is provided by the mathematical demonstration of the model of queuing system. The model has wide applications in different areas including
industry and manufacturing etc
W celu efektywnej eksploatacji rozproszonych źródeł energii i ich kompleksowego wykorzystania w złożonych sieciach elektroenergetycznych przeprowadzono badanie ich właściwości, powstałych w wyniku współdziałania w systemie elektroenergetycznym. Algorytm oceniania wskaźników systemu niezawodności zapewnia wyznaczenie stanu ustalonego. Wyniki obliczeń stanu ustalonego pozwalają na analizę wartości napięć w węzłach sieci oraz odchylenia strat mocy czynnej względem wartości ustalonych normami. Przeprowadzono zaawansowaną analizę dziennych wykresów na podstawie informacji otrzymanej z systemu zdalnego odczytu (АСКОЕ).
Two approaches to calculating distribution energy losses are developed in this paper. The first one is based on the fuzzy load flow, and the other one uses fuzzy clustering technique. The attention at the first approach is devoted to forming the fuzzy numbers that represent loads. Data accessible from the measurements in corresponding substations are considered in this process. Using formed fuzzy loads one fuzzy load flow calculation is made. Results of calculation are fuzzy power losses. Defuzzification gives the deterministic value of average power losses that multiplying with the number of hours for analyzed period gives energy losses. For the second approach, the range of the coefficient that defines fuzziness of clustering is determined, as well as an optimal number of clusters. Analyses shows that the best results are obtained for fuzziness coefficient on the range of 1.1-2, and the number of clusters up to 20.
There is presented a new method for calculation of energy losses in low voltage distribution networks. The method is based on the fuzzy clustering and modified fuzzy clustering techniques, and requires input data that we can collect easily: lengths of lines, number of line segments, number of customers, conductor’s cross section area, conductor’s material, electrical energy delivered by distribution transformers, and peak loadings of distribution transformers. Additional measurements that enable exact calculation of energy losses are required for set of test networks. Presented method is tested on the example of ninety low voltage networks. Optimal number of clusters as well as the optimal value of the parameter m that defines fuzziness of fuzzy clustering was determined.
Tuning fuzzy rule-based systems for linguistic fuzzy modeling is an interesting and widely developed task. It involves adjusting some of the components of the knowledge base without completely redefining it. This contribution introduces a genetic tuning process for jointly fitting the fuzzy rule symbolic representations and the meaning of the involved membership functions. To adjust the former component, we propose the use of linguistic hedges to perform slight modifications keeping a good interpretability. To alter the latter component, two different approaches changing their basic parameters and using nonlinear scaling factors are proposed. As the accomplished experimental study shows, the good performance of our proposal mainly lies in the consideration of this tuning approach performed at two different levels of significance. The paper also analyzes the interaction of the proposed tuning method with a fuzzy rule set reduction process. A good interpretability-accuracy tradeoff is obtained combining both processes with a sequential scheme: first reducing the rule set and subsequently tuning the model.
We propose accurate linguistic modeling, a methodology to design
linguistic models that are accurate to a high degree and may be suitably
interpreted. This approach is based on two main assumptions related to
the interpolative reasoning developed by fuzzy rule-based systems: a
small change in the structure of the linguistic model based on allowing
the linguistic rule to have two consequents associated; and a different
way to obtain the knowledge base based on generating a preliminary fuzzy
rule set composed of a large number of rules and then selecting the
subset of them best cooperating. Moreover, we introduce two variants of
an automatic design method for these kinds of linguistic models based on
two well-known inductive fuzzy rule generation processes and a genetic
process for selecting rules. The accuracy of the proposed methods is
compared with other linguistic modeling techniques with different
characteristics when solving of three different applications
This book proposes systemic design methodologies applied to electrical energy systems, in particular integrated optimal design with modeling and optimization methods and tools. It is made up of six chapters dedicated to integrated optimal design. First, the signal processing of mission profiles and system environment variables are discussed. Then, optimization-oriented analytical models, methods and tools (design frameworks) are proposed. A "multi-level optimization" smartly coupling several optimization processes is the subject of one chapter. Finally, a technico-economic optimization especially dedicated to electrical grids completes the book. The aim of this book is to summarize design methodologies based in particular on a systemic viewpoint, by considering the system as a whole. These methods and tools are proposed by the most important French research laboratories, which have many scientific partnerships with other European and international research institutions. Scientists and engineers in the field of electrical engineering, especially teachers/researchers because of the focus on methodological issues, will find this book extremely useful, as will PhD and Masters students in this field.
The recent rapid decline in PV prices has brought grid parity, or near grid parity for PV in many countries. This, together with an expectation of a similar reduction for battery prices has prompted a new wave of social and academic discussions about the possibility of installing PV-battery systems and "leaving the grid" or "living off-grid". This, if uncontrolled, has been termed the "death spiral" for utility companies.We have developed a decision support tool for rigorous assessment of the feasibility of leaving the grid. Numerous sensitivity analyses are carried out over critical parameters such as technology costs, system size, consumer load, and feed-in-tariff. The results show that, in most cases, leaving-the-grid is not the best economic option and it might be more beneficial to keep the connection with the grid, but minimize the electricity purchased by installation of an optimized size of PV-battery systems.The policy implication of this study is that, from an economic perspective, widespread disconnection might not be a realistic projection of the future. Rather, a notable reduction of energy demand per connection point is a more realistic option as PV-battery system prices decline further. Therefore, policies could be devised to help electricity network operators develop other sources of revenue rather than increasing energy prices, which have been assumed to be the key driver of the death spiral.
Considering the ever-growing demand for electricity, there is a need to introduce new generating facilities - distributed energy sources. This in turn leads to the transformation of the centralized electricity supply system - electricity flow goes from the center to the consumer, into an active decentralized system, characterized by new energy and information flows.
All this points to the need for a new information infrastructure, which should contain a monitoring system of electricity supply mode parameters. Herewith, it is necessary to note the following. Taking into account technical characteristics of new energy sources (their instability), electricity quality is one of the most significant factors that affect the efficiency of both electrical systems, and consumers.
Using existing methods for determining the presence of electricity quality distortion is not acceptable for building real-time monitoring system, based on them. An approach to building real-time monitoring system of electricity quality, which lies in constructing a spatial-temporal distribution of the information signal and the subsequent orthogonal analysis of frequency-temporal changes in its spectral components is presented. Introducing a generalized factor for determining the presence of electricity quality distortion has allowed to carry out its real-time monitoring.
Introduction to Optimization The Binary Genetic Algorithm The Continuous Parameter Genetic Algorithm Applications An Added Level of Sophistication Advanced Applications Evolutionary Trends Appendix Glossary Index.
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Perspektivy i puti razvitija raspredelennoj generacii v Ukraine
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Electrical Engineer 137A: Electric Power Systems. Lecture 2: Introduction to Electric Power Systems
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