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1

Binary shuffled frog leaping algorithm for optimal allocation of power quality monitors in unbalanced distribution system

Mohammadi Ashkan Doust, Mohammadi Mohammad

Journal of Automation Mobile Robotics and Intelligent Systems

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2023

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Vol. 17, No. 4

28--39

EN

This paper deals with optimal detection of number and best locations of power quality monitors (PQMs) in an unbalanced distribution network based on the monitor reach area concept. The proposed model uses binary string, representing the installation mode of PQMs (Yes or No) in each bus of the network. In this paper, the binary version of shuffled frog-leaping algorithm (BSFLA), because of having the ability to improve the search capability with a fast convergence rate, is utilized for the optimization process. The overall cost function is formulated to optimize the two indices, which are the monitor overlapping index and sag severity index. The only optimization constraint in this problem is that the number of monitors that can detect voltage sags due to a fault at a specific bus must not be zero. In this study, DIGSILENT software is utilized for fault analysis while the optimization problem is handled by the BSFLA. To verify the proposed algorithm, the IEEE 34 Bus unbalanced distribution network is considered as a case study and results are compared to similar investigations so as to illustrate the effectiveness of the proposed algorithm.

2

Kamery termowizyjne w ocenie jakości energii elektrycznej

Łatka M., Piechota T.

Prace Instytutu Elektrotechniki

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2016

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Z. 272

83--92

PL

Kamery termowizyjne okazują się być bardzo skutecznymi narzędziami diagnostycznymi w elektroenergetyce. Coraz częściej wykorzystuje się je do bezdotykowych pomiarów stanu urządzeń elektroenergetycznych w stacjach transformatorowych, rozdzielniach itd. Na podstawie otrzymanych obrazów termowizyjnych można ocenić stan urządzeń tam znajdujących się. Czy również takie obrazy termowizyjne mogą posłużyć do oceny jakości energii elektrycznej w wybranym punkcie systemu elektroenergetycznego? Otóż okazuje się, że jak najbardziej. W artykule zaprezentowano zasady przeprowadzania pomiarów oraz wyniki pomiarów kamerą termowizyjną, w postaci obrazów termowizyjnych i ich analizę pod kątem oceny jakości energii elektrycznej w wybranych punktach systemu elektroenergetycznego. Otrzymywane, w bardzo szybki, bezdotykowy i w sumie tani sposób obrazy termograficzne mogą być wskazaniem do przeprowadzenia dalszych, bardziej zaawansowanych pomiarów w zakresie jakości energii elektrycznej.

EN

Thermal imaging cameras prove to be an effective diagnostic instruments in the electric power engineering. These cameras are used more and more frequently in taking touchless measurements of the state of electric power devices in transformer stations, distribution points, etc. On the basis of the received thermal images, it is possible to evaluate the condition of the devices which are located there. Are such images able to serve in the evaluation of the electrical energy quality at the given point of the electric power system? The answer proves to be in the affirmative. In the article, the principles and the results of measurements that have been taken with the thermal imaging camera are presented. The results are delivered as thermal images and their analysis is provided on the basis of the electric power quality at given points of the electric power system. The results, which have been achieved in a quick, touchless and overall inexpensive way, might be an indication to take further, more advanced measurements in the area of electric power quality.

3

Analiza porównawcza funkcjonalności rozproszonych systemów monitoringu jakości energii

Gubański A., Janik P., Kostyła P., Rezmer J., Sikorski T., Szymańda J., Wacławek Z.

Energetyka

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2012

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nr 10

589-594

PL

Artykuł jest przeglądem technicznych i funkcjonalnych rozwiązań oferowanych w zakresie systemów monitoringu jakości energii (SMJE). W odróżnieniu od szerokiego rynku mobilnych urządzeń rejestracji parametrów jakości energii, przeznaczonych głównie do pomiarów doraźnych, skupiono się na rozwiązaniach dedykowanych systemom rozproszonym, synchronicznym, ze zdalnym dostępem do danych pomiarowych, które mają za zadanie monitoring obszarowy, wieIopunktowy. Jednym z postawionych celów jest zdeliniowanie ogólnej struktury SMJE, podanie wymagań technicznych i funkcjonalnych takiego systemu, wykorzystanych następnie jako elementy porównawcze w przeprowadzonym przeglądzie oferowanych obecnie na rynku systemów. Dodatkowym aspektem pracy jest podjęcie tematu standaryzacji danych pomiarowych oraz wykorzystania koncepcji integracji różnych systemów monitoringu jakości energii.

EN

A review is made of technical and functional solutions offered in the area of power quality monitoring systems (POMS). As opposed to the wide market of mobile devices for power quality recording destined mainly for casual measurements, the attention here is focused on solutions dedicated for distributed synchronous systems with remote access to measurement data coming from a multipoint monitoring of the operational area. One of the tasks set by the authors is delining the POMS general structure and specilying technical and functional requirements of such system, subsequently helping to compare the available solutions offered in the market. Additionally, the need for data standardization and integration of various devices and subsystems has been mentioned.

4

Combined monitoring and time-frequency analysis for transients in wind energy systems

Łobos T., Sikorski T., Amarís H, Alonso M, Florez D

Computer Applications in Electrical Engineering

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2010

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Vol. 8

261--269

EN

The aim of this paper is the application of selected time-varying power quality indices combined with detailed time-frequency analysis for assessment of transients in wind energy system. Presented proposition utilizes short-term harmonic distortion in voltage (STHDV) characteristic as an indicator for detail local time-frequency analysis of the transients. Introduced ideas can be treated as hybrid system absorbing both power quality indices and time-frequency representation.

5

Power quality monitoring in regional distribution networks in the Czech Republic

Santarius P., Krejčí P., Sikora T., Velička R.

Zeszyty Naukowe. Elektryka / Politechnika Opolska

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2008

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Vol. 323, z. 60

205-206

EN

The liberalisation of the market with electrical energy came into effect in the Czech Republic on 1st January 2002. In the first phase, big consumers (consumption over 40 MWh per year) were affected. This market has been liberalized completely since 2006. In our opinion, power companies pay sufficient attention to ensuring the required technical parameters. Customers usually have only one technical choice of the supply of electrical energy. But in the liberalised market environment entitled customers can choose from several traders of electrical energy. The key criterion for the choice is surely the offered price. But in steady market environment, where the offered prices will be balanced, other parameters will be more important when making decisions, and we expect that ensuring quality parameters will increase its role. The quality of electrical energy can be looked upon from the point of view of technical parameters of the supplied voltage and current, or from the commercial point of view (the quality of the supplied electrical energy and services). In the power company CEZ in the North Moravia region the monitoring of a number of selected parameters of the quality of electrical energy (harmonics, flicker, unbalance) is being done in cooperation with research laboratories of the Faculty of Electrical Engineering and Computer Science, VŠB - Technical University of Ostrava. The monitoring is being done in a complex way in 59 feeding points 400 V, always in one week intervals, and at the same time on all voltage levels (HV, MV and LV). The whole cycle lasted for 3 years, and currently the fourth cycle of monitoring is realised. 3 full cycles enables comparing of the state after twice three years. In the paper, the results of the first, second and third cycle of the complex monitoring will be summarised together with the comparison of the changes of parameters after three years. In the second cycle of monitoring there were measured currents in the neutral conductor. The results of monitoring of harmonic components of current in the neutral conductor will be presented in the paper. Beyond period monitoring are installed on chosen 100kV substations stationary monitoring devices. Analyzers QWave Power and QW Light (by the LEM Company) are installed here, so it is possible to record as many informations about both individual voltage quality parameters and events in the distribution system as possible. QWave Power measures all parameters of voltage quality simultaneously and compares these with limit values of the standard CSN EN50160, and further analyses the current. QWave Light is a simplified version that evaluates only voltage in all its guaranteed and indicative parameters. The instruments are successively installed in other MV and HV nodes. This paper summarizes results of 10 years of long-term periodical power quality monitoring. Further are in detail described methods of power quality monitoring methods with focus on use of composite measuring instruments.

6

Digital measurement of transient disturbances in electric power network with additional lowpass analog circuit

Duda K., Bień A.

Metrology and Measurement Systems

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2007

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Vol. 14, nr 2

283-289

EN

The paper presents a DSP-based system for measurement of the short-term transient distortions in electric power networks. These distortions typically possess short duration times and high amplitude values and thus they are very di.cult to acquire by standard digital data acquisition systems. We propose to apply an additional analog lowpass RC circuit before digital data acquisition. A properly chosen analog RC filter extends the duration time of transient distortion and simultaneously reduces its amplitude making it significantly simpler to acquire digitally. Next, digital signal processing is used for cancelling the analog convolution of the acquired signal with a RC filter. The paper discuses results obtained for di.erent con.gurations of the proposed measurement system including RC filter selection and digital deconvolution filter design. The algorithm was implemented in a Texas Instruments C617 DSK toolkit. Laboratory experiments with voltage signals are presented in the paper.

7

Monitoring of the power quality in the distribution networks in the Czech Republic

Santarius P., Gavlas J., Krejci P., Vasenka P.

Zeszyty Naukowe. Elektryka / Politechnika Opolska

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2005

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Vol. 299, z. 55

189-202

EN

The liberalization of the market with electrical energy, which came into effect in the Czech Republic in 2002, brings about new requirements as far as the quality of the supplied electrical energy is concerned. In the paper, the results of a long-term monitoring of the selected parameters of the quality in the regional power company are summarised, (including the evaluation of the trends of change), the results of the monitoring of the extreme power quality parameters together with the results of evaluation of voltage drops in the selected sites of the regional power company.

8

Successful power quality monitoring

Sumper A., Sudria A., Rull J.

Electrical Power Quality and Utilisation. Magazine

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2005

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Vol. 1, nr 1

37--43

EN

Monitoring power quality often seems the solution for power quality problems. However, in order to solve power quality problems something more than simple installation of power quality monitors at the site is needed. This article attempts to dissipate any doubts of engineers about organizing a monitor program to solve power quality problems. It can be organized in three programs: an overall power quality program, the power quality survey and die immunization program. In all three programs, monitoring plays a decisive role. Furthermore, an overview of the main monitor features will be given.

9

Jakość energii elektrycznej na rynku liberalizowanym

Santarius P., Gavlas J., Vašenka P.

Zeszyty Naukowe. Elektryka / Politechnika Opolska

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2002

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Vol. 280, z. 51

591-598

PL

Rozprzestrzenianie się urządzeń z nieliniową charakterystyką w dystrybucyjnych sieciach niskiego napięcia (nn) ( takich jak telewizory, komputery, żarówki kompaktowe, itp.) powoduje degradację jakości energii elektrycznej. Do oceny aktualnego stanu i do projektu potrzebnych pomiarów została wykonana seria pomiarów w sieci dystrybucyjnej, które były zogniskowane przeważnie na złożonej ocenie kilku ważnych parametrów jakości energii elektrycznej (harmoniczne, wahania napięcia i asymetria napięcia) w dystrybucyjnej sieci regionalnej dystrybucyjnej spółki w Republice Czeskiej. Znaczenie pomiarów jakości energii elektrycznej jest rosnące, ponieważ nowe prawo energetyczne zacznie otwierać rynek energii elektrycznej w roku 2002. Pomiary i ocena jakości były realizowane w więcej niż pięćdziesięciu punktach węzłowych sieci dystrybucyjnej zgodnie z normą EN 50160. W referacie tym są końcowe wyniki złożonych badań z istotnym porównaniem w stosunku do standardu EN 50160.

EN

Spreading of appliances with non-linear characteristic in the LV distribution networks (such as TV sets, computers, compact fluorescent lamps, etc.) causes degradation of a supplied power quality. For evaluation of current status and for design of needed measures was performed series measuring in the distribution networks which were focused mostly on a complex evaluation of some important quality parameters (harmonics, voltage fluctuation and voltage unbalance) in the distribution network of a regional distribution company in the Czech republic. The importance of the power quality monitoring is increasing because the riew energetic law will start opening the electricity market since the year 2002. The measures and the evaluation of quality was realised on more then 50 supply nodes of the distribution network according to the standard CSN EN 50160. In the paper there are summarised results of a complex research with relevant evaluation in relation to the standard CSN EN 50160.