Wyniki 1-3 spośród 3 dla zapytania: authorDesc:"Dmitry KALYUZHNIY"

Analytical methods for determination of the factual contributions impact of the objects connected to power system on the distortion of symmetry and sinusoidal waveform of voltages DOI:10.15199/48.2015.11.23

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One of the main reasons of the significant economic losses of consumers and suppliers of electrical energy is the use of low-quality electricity. In the event of such situation, the solution of financial compensation issue of damages to the injured party is based on determination of factual contributions of entities connected to power network to the deterioration of power quality at the point of common coupling. So far, there are many methods of determination of the factual contributions to the reduction of power quality that are different both in methodology and in technical features of their implementation. The results of analysis of the present methods and their classification are given and the application field of each of them is identified in the article. Streszczenie. Jedną z głównych przyczyn znacznych strat gospodarczych u odbiorców i dostawców energii elektrycznej jest użytkowanie energii elektrycznej o obniżonej jakości. W takiej sytuacji rozwiązaniem powinna być finansowa rekompensata strat dla pokrzywdzonej strony oparta na określeniu udziału podmiotów przyłączonych do sieci elektroenergetycznej w pogorszenia jakości energii elektrycznej w punkcie wspólnego przyłączenia. Istnieje wiele metod określania negatywnego wpływu odbiorców na jakość energii elektrycznej, różniących się zarówno metodologii jak i technicznymi sposobami ich realizacji. W artykule dokonano analizy obecnych metod, podano ich klasyfikację oraz określono zakresy ich stosowania. (Analityczne metody określania wpływu rzeczywistego udziału obiektów przyłączonych do systemu zasilania na zaburzenia symetrii i sinusoidalnego przebiegu napięć). Keywords: Power quality, the factual contribution, voltage asymmetry, voltage waveform distortion Słowa kluczowe: jakość energii, rzeczywisty udział, asymetria napięcia, odkształcenie napięcia Introduction The distribution and consumption of electrical energy (EE) of lower quality leads to the significant economic damages [1][...]

Compensation of reactive power in electrical supply systems of large industrial enterprises DOI:10.15199/48.2015.11.22

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The issues of reactive power compensation, typical for large industrial enterprises are discussed in the article. The approach to reactive power compensation is considered as an optimization problem. On the one hand, this approach allows minimizing the costs of compensating devices; on the other hand, it allows economically justifying the amount of cost for the "consumption" of reactive power born by the enterprise. The practical solution of the formulated problem in the existing large metallurgical plant in Mariupol (Ukraine) is presented. Streszczenie. W artykule omówiono zagadnienia kompensacji mocy biernej, typowe dla dużych przedsiębiorstw przemysłowych. Zagadnienia kompensacji mocy biernej potraktowano jako problem optymalizacji. Z jednej strony pozwala to na minimalizację kosztów urządzeń kompensacyjnych; a z drugiej na ekonomiczne uzasadnienie wysokości kosztów za "pobór" mocy biernej przez przedsiębiorstwo. Zaprezentowano praktyczne rozwiązanie sformułowanego problemu w istniejącym dużym zakładzie metalurgicznym w Mariupolu (Ukraina). (Kompensacja mocy biernej w systemach zasilających duże zakłady przemysłowe). Keywords: reactive power, reactive power compensation, payment for reactive energy. Słowa kluczowe: moc bierna, kompensacja mocy biernej, opłaty za energię bierną. Introduction At the present time an increase of reactive power (RP) "consumption" in all areas of industry and national economy is observed. Users of electric energy began to operate with low power factor and thus the increase of reactive power consumption has led to a number of negative consequences. Experts estimate that among the reasons of emergence and development of the most serious damages and technological breakdowns in power supply systems in different countries, that have led to disconnection of a significant amount of consumers, was the deficit of RP in power supply systems and the insufficient power of installed RP sources [1]. Ther[...]

Mathematical model for assessment of voltage disturbing sources in networks with distributed power generation DOI:10.15199/48.2019.03.12

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Among other challenging topical problems in modern electrical power systems, there are the identification of disturbing sources (DSs) in network and assessment of their contributions into power quality (PQ) deterioration at a point of evaluation (POE). The proliferation of renewable energy sources like PV panels and wind generators in electrical systems is transforming centralized power supply systems (PSSs) into those with distributed generation (DG) and increasing importance of PQ problems. There are still no enough good methods for modelling customers’ installations especially those incorporating generating units. This paper considers how to identify DSs in such installations and assess their impact on PQ at a random POE that is usually some point of common coupling (PCC). The presented study offers DS topologies and the procedure for defining the parameters of a DS equivalent circuit on the basis of standard measurements [1]. There are presently a lot of methods proposed to find a solution for the problem. The contemporary methods used to identify and assess impact of voltage disturbing sources on PQ at a POE are shortly described below. A more comprehensive review can be found in [2-5]. The list of used abbreviations is provided at the end of the paper. Review of existing methods The models based on single-line Thevenin or Norton equivalent circuits (Fig. 1) are the prevailing ones [3-12]. Both a customer’s installation (CI) and an upstream power system (PS) are represented as a voltage source in series with impedance for each sequence q and harmonic. Such an assessment of disturbing sources is simple, but it is applicable only for the case with a single POE, a single CI and a single dominating DS on either utility or consumer’s side. Another disadvantage explained below is a need to have an equivalent circuit for each symmetrical component. There are also some methodological problems related to th[...]

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