Wyniki 1-10 spośród 28 dla zapytania: authorDesc:"Hussain SHAREEF"

Power quality diagnosis in distribution networks using support vector regression based S-transform technique

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This paper presents a novel method for performing automatic power quality diagnosis to identify the causes of short duration voltage disturbances such as voltage sags and swells. Such voltage disturbances can be caused by permanent or non permanent faults. A permanent fault causes permanent damage and power interruption to the customers whereas a non permanent fault can be categorized as either transient or incipient faults. In the proposed power quality diagnosis method, a time frequency analysis technique called as the S-transform is used to analyse and extract features of voltage disturbances recorded from the power quality monitoring system. The support vector regression which is an intelligent technique is then used identify whether the voltage disturbances are caused by permanent, non permanent, transient or incipient faults. Test results proved that the proposed power quality diagnosis method can provide accurate diagnosis on the causes of short duration voltage disturbances. Streszczenie. W artykule przedstawiono nową metodę przeprowadzania automatycznej diagnostyki jakości energii elektrycznej do identyfikacji przyczyn krótkoczasowych zakłóceń napięcia, takich jak zapady napięcia. Zaburzenia napięcia mogą być spowodowane przez długotrwałe lub chwilowe awarie. W proponowanej metodzie diagnozowania jakości zasilania, zastosowano transformatę S do ekstrakcji charakterystyk zarejestrowanych przebiegów z systemu monitoringu. Zastosowano regresję SVR jako technike inteligentna , pozwalajaca na rozróżnienie pomiędzy typami awarii.. Wyniki badań wykazały, że proponowana metoda diagnozowania jakości zasilania może zapewnić dokładną diagnozę na temat przyczyn zaburzeń napięcia o krótkim czasie trwania. (Analiza jakości energii w sieciach rozdzielczych w oparciu o transformatę S bazującą na regresji wektora wspierającego (SVR)) Keywords: power quality; power quality diagnosis; Support Vector Regression; S-transform Słowa kluczowe: jakość energ[...]

Application of artificial intelligent techniques in PSS design: a survey of the state-of-the-art methods

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Power system stabilizers (PSSs) are the most well known and efficient devices to damp the power system oscillations caused by interruptions. Low frequency oscillation problems are very difficult to solve because power systems are very large, complex and geographically distributed. Hence, it is necessary to employ most efficient optimization methods to take full advantages in simplifying the problem and its implementation. These optimization methodologies and techniques are widely diverse and have been the subject of ongoing enhancements over the years. This paper presents a survey of literature on the various optimization methods applied to solve the PSS problems. Streszczenie. System stabilizacji mocy PSS jest powszechnie stosowaną I skuteczną metodą tłumienia oscylacji spowodowanych przerwaniami. Oscylacje niskiej częstotliwości są trudne do eliminacji ze względu na ich złożoność i rozległość przestrzenną. Dlatego warto poszukiwać skutecznych metod optymalizacji metody PSS. Artykuł przedstawia metody optymalizacji wykorzystujące sztuczną inteligencję. (Wykorzystanie technik sztucznej inteligencji przy projektowaniu systemów stabilizacji mocy systemu energetycznego) Keywords: artificial intelligence techniques, optimization methods, power system stabilizer. Słowa kluczowe: sztuczna inteligencvja. Metody optymalizacji, stabilizacja w systemach energetycznych. 1. Introduction With the advent of automatic voltage regulators (AVRs) in the late 1950s, installation of AVRs on power generating units become a common practice. Unfortunately, the high performance of these voltage regulators caused a destabilizing phenomenon on the power system. Most of the problems are associated with the low frequency oscillation in interconnected power systems, especially in the deregulated paradigm. Small magnitude and low frequency oscillation often remained for a long time. To provide fast damping for the system and thus improve the dynamic performance, a[...]

Optimal placement and sizing of Static Var Compensators in power systems using Improved Harmony Search Algorithm

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This paper presents the application of the improved harmony search (IHS) algorithm for determining the optimal location and sizing of static Var compensator (SVC) to improve the voltage profile and reduce system power losses. A multi-criterion objective function comprising of both operational objectives and investment costs is considered. The results on the 57-bust test system showed that the IHS algorithm give lower power loss and better voltage improvement compared to the particle swarm optimization method in solving the SVC placement and sizing problem. Streszczenie. Artykuł przedstawia zastosowanie algorytmu IHS (Improved harmony search) do określania optymalnej lokalizacji kompensatora mocy biernej. Rezultaty testów wykazały że algorytm zapenia mniejsze straty mocy oraz zniekształcenia w porównaniu do innych metod optymalizacji. (Optymalizacja lokalizacji kompensatora mocy biernej z wykorzystaniem algorytmu IHS) Keywords: Static Var Compensator, Power Loss, Voltage Profile, Harmony Search Algorithm Słowa kluczowe: komensacja mocy biernej, algorytm HIS. Introduction Flexible AC transmission system (FACTS) can provide benefits in increasing system transmission capacity and power flow control flexibility and rapidity [1]. FACTS devices are power electronic converters that have the capability of controlling various electrical parameters in transmission circuits, facilities, both in steady state power flow and dynamic stability control. These devices include thyristor controlled series compensator, static Var compensator (SVC), unified power flow controller, static compensator (STATCOM), etc [2]. The most widely used shunt FACTS devices within power networks is the SVC due to its low cost and good performance in system enhancement. It is a shunt-connected static Var generator or absorber whose output is adjusted to exchange capacitive or inductive current so as to provide voltage support and when installed in a proper location, it [...]

Reliability Improvement in Distribution Systems by Optimal Placement of DSTATCOM Using Binary Gravitational Search Algorithm

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In this paper, a new method for improving reliability level of distribution systems is presented by employing optimal placement of DSTATCOM. The binary version of the Gravitational Search algorithm (BGSA) is used to solve the DSTATCOM optimal placement problem. The simulation results show that the proposed method is efficient and feasible for improving the system reliability level by reducing load outages and momentary interruptions. Streszczenie. Przedstawiono nową metodę poprawy niezawodności system dystrybucji energii dzięki optymalizacji DSTATCOM. Optymalne położenie DSTATCOM było określane na podstawie algorytmu BGSA. Uzyskano [poprawę dzięki dedukcji przerw w obciążeniu i chwilowych zaników. (Poprawa niezawodności systemu dystrybucji energii dzięki optymalnemu ustawieniu DSTATCOM) Keywords: Voltage sag, Reliability, Distribution Systems, DSTATCOM, GSA, Power Quality. Słowa kluczowe: niezawodność, system dystrybucji energii, DSTATCOM. Introduction The unprecedented changes in the technology have changed the customer’s expectation about quality and continuity of energy from power utilities. A minute disturbance such as voltage sag may cause large amount of financial loss due to increased level of dependency on electricity in industrial processes. Therefore, utilities have to consider seriously the quality and reliability of the power supply. Reliability is defined as the ability of a system to perform required functions under stated conditions for a given period of time. In power systems, reliability and security have the same implication. For example, a distribution system whose security level is low is said to be unreliable and vice versa. There are many reliability indices which are categorized in three groups, namely, sustained interruption indices, load based indices and momentary indices that are used for reliability assessment [1]. Among them, load based index such as the average system interruption frequency ind[...]

Heuristic Optimization Techniques to Determine Optimal Capacitor Placement and Sizing in Radial Distribution Networks: A Comprehensive Review

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Capacitors in power systems are used to supply reactive power to minimize loss and to improve the voltage profile. The appropriate placement of capacitors is also important to ensure that system power losses and total capacitor costs are minimal. The capacitor placement problem is commonly solved using heuristic optimization techniques which are diverse and have been the subject of ongoing enhancements. This paper presents a survey of the literature from the last decade that has focused on the various heuristic optimization techniques applied to determine optimal capacitor placement and size. Streszczenie. Kondensatory używane są w sieciach zasilających do poprawy jakości napięcia - zmniejszenia mocy biernej. Ważną rolę odgrywa umiejscowienie kondensatora. W artykule zaprezentowano przegląd literaturowy prac na temat metod optymalizacji umożlwiających określenia optymalnej pozycji I wielkości kondensatora. (Heurystyczne techniki optymalizacji umiejscowienia kondensatora w promieniowych sieciach zasilających - przegląd stanu wiedzy) Keywords: Capacitor Placement, Radial Distribution Network, Heuristic Optimization, Power System Harmonics. Słowa kluczowe: sieci zasilające, kondensator, zawartość 1. Introduction Shunt capacitors in distribution networks are used for various purposes: reducing power loss, improving the voltage profile along feeders, and increasing the maximum transmitted power in cables and transformers. To reduce power loss, shunt capacitors, which are commonly installed in power distribution networks, are used to compensate for reactive power. However, the installation of shunt capacitors in distribution networks requires consideration of their appropriate location and size. Capacitor placement is important to maximize loss reduction by properly installing shunt capacitors while minimizing shunt capacitor costs. Distribution networks are unbalanced due to mutual coupling between phase conductors and loading on the di[...]

Optimal Placement and Sizing of Shunt FACTS Devices in Power Systems Using Heuristic Optimization Techniques: a Comprehensive Survey

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The Static Var Compensator (SVC) and the Static Synchronous Compensator (STATCOM), as two components of Flexible AC Transmission System (FACTS) devices, play an important role in controlling the reactive power flow to the power network. Because of economic considerations, identifying the best location for installing the SVC and STATCOM is also important. The FACTS devices placement problem is commonly solved using heuristic optimization techniques which are diverse and have been the subject of ongoing enhancements. This paper presents a survey of the literature from the last decade that has focused on the various heuristic optimization techniques applied to determine optimal placement and sizing of the SVC and STATCOM. Streszczenie. W artykule analizuje się optymalne usytuaowanie elementów SVC I STATCOM w systemie FACTS. Przedstawiono stan wiedzy wykorzystania do tego celu różnych heurystycznych metod optymalizacji. (Optymalne usytuowanie elementów SVC i STATCOM w systemie FACTS) Keywords: Static Var Compensator (SVC), Static Synchronous Compensator (STATCOM), Heuristic Optimization, Placement, Sizing. Słowa kluczowe: SVC - statyczny kompensator mocy biernej, STATCOM - statyczny kompensator synchroniczny 1. Introduction Flexible AC Transmission Systems (FACTS) can provide benefits in increasing system transmission capacity and power flow control flexibility and speed [1]. FACTS devices are power electronic converters that have the capability to control various electrical parameters in transmission circuits and facilities, both in steady state power flow and dynamic stability control [2]. These devices include Thyristor Controlled Series Compensator (TCSC), Static Var Compensator (SVC), Unified Power Flow Controller (UPFC), Static Compensator (STATCOM), and others [3]. The SVC is the most widely used shunt FACTS device in power networks because of its low cost and good performance in system enhancement. It is a shuntconnected static[...]

Comparison of Decentralized Voltage Control Methods for Managing Voltage Rise in Active Distribution Networks

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Integration of distributed generations (DGs) to distribution systems has posed several technical challenges for network operators. One of the main problems that has received widespread attention is the voltage rise issue. This issue has led researchers worldwide to find ways to control voltage so that an acceptable limit is maintained and delivered to consumers. In networks with DGs, the methods of voltage control have been identified as coordinated or centralized control and decentralized control. This paper presents the results and comparisons of a simulation that used these decentralized voltage control methods in managing voltage rise issues in distribution systems with DGs. Streszczenie. W artykule przedstawiono porównanie metod sterowania zdecentralizowanego, wykorzystywanego do kontroli dopuszczalnej amplitudy napięcia w sieci, zawierającej rozproszone generatory energii elektrycznej. W tego rodzaju sieci możliwe są nieoczekiwane, skoki napięcia, co przekłada się na jakość energii, dostarczanej do użytkowników i działanie odbiorników. (Porównanie zdecentralizowanych metod kontroli napięcia w kontroli skoków napięcia w aktywnych sieciach elektroenergetycznych). Keywords: Distributed generations (DGs), voltage rise, centralized and decentralized methods, voltage control. Słowakluczowe: Generacja rozproszona (DGs), skok napięcia, metody zcentralizowane i zdecentralizowane, kontrola napięcia. 1. Introduction The presence of distributed generations (DGs) in distribution systems has created several challenges and disadvantages in terms of delivery of power quality, protection issues, and voltage support. The need for distribution network operators (DNOs) to control voltage at its acceptable limits is required to maintain the delivery of power to the customers. Effective delivery of power consequently reduces the issues of power quality and losses. According to [1], an active distribution network (ADN) is defined as a distribution net[...]

Genetic algorithm for damping of power system oscillations

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In this paper, Genetic algorithm (GA) optimization method is presented for optimal design of power system stabilizer (PSS). The design problem of the PSS parameters is formulated as an optimization problem and GA optimization method is used to search for optimal PSS parameters. The 2-area-4-machine power system, under a wide range of system configurations and operation conditions is investigated to illustrate the performance of the GA. The performance of the optimization method is compared with the conventional power system stabilizer. The eigenvalue analysis and non-linear simulation results are presented and compared to show the effectiveness of the GA optimization method in optimal tuning of PSS, to enhance power system stability. Streszczenie. W artykule zaprezentowano metodę optymalizacji algorytmu stabilizacji systemu zasilania, z wykorzystaniem algorytmu genetycznego. Opracowana metoda została porównana w działaniu z konwencjonalnym stabilizatorem sieci. Przedstawiono wyniki przeprowadzonych symulacji nieliniowych i analizy wartości własnych. (Algorytm genetyczny w tłumieniu oscylacji w systemie elektroenergetycznym). Keywords: Genetic Algorithm, Power System Stabilzer, Design, Low Frequancy Oscillation Słowa kluczowe: algorytm genetyczny, stabilizator systemu elektroenergetycznego, projektowanie, oscylacje niskiej częstotliwości. Introduction Constantly increasing intricacy of electric power systems has enhanced interests in developing superior methodologies for power system stabilizers (PSSs). Low frequency oscillation modes have been observed when power systems are interconnected by weak tie-lines [1]. PSSs are the most efficient devices for damping both local mode, and inter-area mode. The generators are equipped with PSS, which provides supplementary feedback and stabilizes the signal in the excitation system [2, 3]. The problem of PSS design is to tune the parameters of the stabilizer so that the damping of the system[...]

Effect of grid-connected photovoltaic systems on static and dynamic voltage stability with analysis techniques - a review DOI:10.15199/48.2015.06.27

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This paper presents an overview on the effect of grid-connected photovoltaic (PV) system on static and dynamic voltage stability and discusses the analysis techniques used to quantify the effect. A review on the published works showed that the PV system design, PV parameters and the distinct design of power system network affect system voltage stability. Furthermore, a discussion is also made on the optimization techniques used for determining optimum PV placement and sizing for the purpose of improving voltage stability. Streszczenie. W artykule dokonano przeglądu metod analizy wpływu dołączenia systemu fotowoltaicznego na właściwości statyczne i dynamiczne sieci. Odpowiedni projekt wpływa na stabilność napięciową. Analizowano też metody optymalizacji położenia systemu. Przegląd metod analizy wpływu podłączenia systemu fotowoltaicznego na właściwości statyczne i dynamiczne sieci Keywords. Grid-connected solar PV system; static voltage stability; dynamic voltage stability; Optimum PV placement and sizing Słowa kluczowe: system fotowoltaiczny, system fotowoltaiczny dołac\ony do sieci 1. Introduction Renewable energy sources, such as photovoltaic (PV) systems, wind turbines, and fuel cells, are integrated into conventional power systems to address fossil fuel deficiency, intensifying energy demand, and environmental pollution. Among all types of renewable energy resources, solar PV receives major attention for its promising energy resources and low-cost installation. The fundamental operation system of solar PV differs from other generating systems. Solar PV converts sunlight into DC power using semiconductor solar cells. The DC power is then converted into AC power through a DC-to-AC converter. Given this electronic conversion system, solar PV does not have inertia, and its dynamic behavior depends on the characteristics and controls of inverters. PV systems are categorized into small-scale and large-scale PV systems; the former is [...]

A Review of Techniques for Optimal Placement and Sizing of Electric Vehicle Charging Stations DOI:10.15199/48.2015.08.29

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Fossil fuel depletion and greenhouse gas emission from the burning of fossil fuels motivates policymakers to find an alternative road transport system. Electric vehicles (EVs) are considered as one of the best solutions in road transportation system as EVs can reduce the dependence on fossil fuel and diminish transportation-related emissions from carbon dioxide emission and other pollutants. The key issue in this system is recharging the EV batteries before they are exhausted. Thus, charging stations (CS) should be carefully located to ensure that EV users can access the stations within their driving range. This study represents a survey of the literature focused on the numerous optimization techniques employed from the last decade to determine the optimal EVCS placement and sizing problems. Streszczenie. Zasadniczym problemem w rozwoju pojazdów elektrycznych jest zapewnienie nich naładowania przed pełnym rozładowaniem. Dlatego równie ważnym zagadnieniem jest właściwe rozplanowanie lokalizacji stacji ładowania. W artykule analizowane są różne techniki optymalizacji lokalizacji jak i wielkości stacji. Przegląd technik optymalnej lokalizacji stacji ładowania pojazdów elektrycznych Keywords: electric vehicle, placement, sizing, optimization techniques Słowa kluczowe: pojazdy elektryczne, stacje ładowania Introduction Recently, the global community realized that the planet is harmed by the effects of global warming and various problems that the lack of care causes. Internal combustion engine (ICE) is considered as one of the most important components in the transportation sector for creating such problems through carbon dioxide (CO2) emissions, which is the main perpetrator of global warming. Fossil fuel depletion is another concern in the transportation system [1]. Interestingly, an electric vehicle (EV) does not contaminate the earth or contribute to the problems of high oil price. EVs are a forthcoming technology that has numerous bene[...]

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