scholarly journals Elimination of interharmonic currents by a FAP using the technique of compensation global

Author(s):  
Mohamed Ali Moussa ◽  
Bachir Belmadani ◽  
Ahmed Wahid Belarbi ◽  
Rachid Taleb

<p>This document is a contribution to improve the quality of electrical energy in the distribution network.<br />In this article we will present a method that allows us to clean up in a very considerable way the electrical network of both harmonics and inter harmonics provoked, basically by the ultrafast switches used when controlling a PWM inverter supplying a three-phase asynchronous motor. We notice that this method can be generalized for other loads creating inter-harmonics.<br />This proposed method was simulated using the MATLAB/SIMULINK software and had given remarkable results (there is a considerable reduction in total harmonic distortion (THD) of source current from 29.52% to 0.82%)</p>

2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Asmar Asmar ◽  
Wahri Sunanda

One of the performances of the electric power system can be seen from the quality of electrical energy. In this study, the measurement of the quality of electrical energy was carried out using a power quality meter to obtain the values of current, voltage, frequency, total current harmonic distortion and total voltage harmonic distortion in the building of the Faculty of Engineering, Universitas Bangka Belitung. From measurements on the 3 existing buildings, it was found that the measured voltage value range was still at  + 5% to - 10% of the 220 Volt secondary distribution voltage value and the frequency value was still in the range of 49.5 Hz to 50.5 Hz. The total value of voltage harmonic distortion is still below the required value, but the total value of current harmonic distortion is above the required value.


Author(s):  
Salomón Noé Turiján-Altamirano ◽  
Germán Adul Muñoz-Hernández ◽  
Omar Chávez-Cano ◽  
Julio Rodríguez-González

The present work shows the development of a platform, based on an embedded system, for the monitoring of disturbances present in the electrical network, such as the detection of swells and sags, as well as the measurement of the first 31 harmonics. It describes the integration of the prototype at the hardware level and the design of the algorithms for its operation. Finally, the results obtained from the tests carried out with the device in operation are presented.


2009 ◽  
Vol 62-64 ◽  
pp. 53-59 ◽  
Author(s):  
B.A. Adegboye

The paper explores power quality disturbances on a specified section of the distribution network of a Textile Industry in Kaduna State of Nigeria. The 33kV PHCN incoming to the industry is stepped down to 11kV by a 7.5MVA, 33/11kV three-phase transformer. This transformer supplies various 11/.415kV transformers present in the distribution network. Another 11kV PHCN incoming is used in event of any failure from the 33/11kV transformer. The paper focuses on Transformer No. 1, a 150kVA, 11/.415kV three-phase transformer operating at 0.9 power factor, located at printing and dying (P/D) building 1. Majority of the loads on it are inductive. Measurements were taken at the secondary terminal of this transformer by the use of the Harmonitor 3000 power analyzer, which generates the voltage and current waveforms, power factor, voltage and current total harmonic distortion and the apparent power of the red, yellow and blue phases of the transformer. Analyses of these data reveal the disturbances due to harmonics in the phases and neutral of the transformer. The effect of the harmonic current is seen as poor power factor of the transformer. Considering the observations and analyses of the power quality of the transformer 1 (P/D), the paper proposes some recommendations for improving the power quality of the distribution network under study.


2021 ◽  
Vol 11 (4) ◽  
pp. 1684
Author(s):  
José Teixeira Gonçalves ◽  
Stanimir Valtchev ◽  
Rui Melicio

In this paper, a new way to mitigate the current interactions is proposed. The problem of current interactions arises when a modular three-phase (3-phase) rectifier (three single-phase modules) with boost converter for power factor correction (PFC) is used. A new differential-mode choke filter is implemented in the developed boost converter. The choke here is a specially made differential inductor in the input of the boost converter that eliminates the known current interactions. To prove the new concept, a study of the level of mitigation of the current interactions is presented. The control is operated in continuous driving mode (CCM), and the popular UC3854B circuit was used for this. The rectifier proposal is validated through a set of simulations performed on the PSIM 12.0 platform, as well as the construction of a prototype. With the results obtained, it is confirmed that the differential-mode choke filter eliminates the current interactions. It is observed that at the input of the rectifier, a sinusoidal alternating current with a low level of harmonic distortion is consumed from the grid. The sinusoidal shape of the phase current proves that a better power factor capable of meeting the international standards is obtained, and that the circuit in its initial version is operational. This proven result promises a good PFC operation, to guarantee the better quality of the electrical energy, being able to be applied in systems that require a high PFC, e.g., in battery charging, wind systems, or in aeronautics and spacecrafts.


Author(s):  
V. I. Zatsepina ◽  
E. P. Zatsepin ◽  
P. I. Skomorokhov

In most cases, any abnormal mode in the distribution electrical network is eliminated by the action of relay protection and automation devices (RPA), i.e. - there is a shutdown of the damaged item. It is much more difficult to constantly maintain the normal key indicators of the quality of electrical energy in the network. With the advent of controlled voltage converters based on transistors IGCT and IGBT, static synchronous compensators STATCOM were developed. The main disadvantage of this kind of device is that the control output generated by them is static. Under conditions of increased likelihood of abnormal conditions, their dynamic compensation will be much more effective. In the process of research, the methods of dynamic continuous action of voltage on a sinusoid in a distribution electric network were used. The development of a theoretical approach was accompanied by constant monitoring of existing and developed technical solutions associated with the task set in the work. The object of the study was the distribution electrical network of industrial enterprises with a sharply alternating nature of negative network perturbations. A method has been developed for dynamic suppression of amplitude-phase voltage distortions on the basis of restoring the voltage curve due to the continuous introduction of a compensation voltage curve into the network via a booster transformer. A faster formation of the control action in comparison with analogues allows us to more effectively respond to negative network perturbations in distribution networks, especially if the nature of their occurrence changes dramatically. The proposed method is designed to maintain the quality of electricity within acceptable limits in accordance with the requirements of Russian State Standard 32144-2013.


Author(s):  
V. I. Biryulin ◽  
D. V. Kudelina ◽  
O. M. Larin

THE PURPOSE. To consider issues related to the study of methods for determining the sources of violations of the quality of electrical energy in power supply systems, in particular consumers which create rapid voltage changes or voltage fluctuations that create rapid changes in the luminous flux in electric lighting installations. Show that electrical receivers with a sharply variable operating mode are sources of fluctuations in the consumed current and voltage in the electrical network of power supply systems, which in turn manifests itself in the form of unacceptable values of one of the indicators of the quality of electricity - flicker, defined as the subjective perception of fluctuations in the luminous flux of lighting devices. To study the possibilities of determining the places of occurrence of significant voltage fluctuations without the use of expensive and complex instruments for measuring flicker values in the electrical network. To develop a simplified method for determining the locations of electricity consumers that negatively affect the operation of electric lighting systems and, ultimately, the vision of personnel. Conduct a check on a computer model of a simplified method for determining the places of occurrence of voltage fluctuations that are inadmissible in their magnitude, which are expressed in the appearance of significant doses of flicker that exceed the standard values.METHODS. Solving the problem, a computer model was used, created in the Simulink extension package of the Matlab scientific and technical calculation system.RESULTS. The article describes the relevance of the problem, discusses the quality of electricity in power supply systems. It has been shown using experimental data that in electrical networks there is an excess of the standard values of flicker doses. The possibility of using interharmonic components of the mains voltage to determine the sources of unacceptable doses of flicker is considered. A simplified method for finding flicker sources based on obtaining the values of the derivatives of currents at various points of the electrical network is presented. Computer simulation of an electrical network diagram with electrical receivers, which have both calm and sharply variable nature of work, has been performed. It is shown that the use of the values of the derivatives of the current at various points of the electrical network makes it possible to identify the sources of the occurrence of unacceptable doses of flicker.CONCLUSION. The occurrence of significant rapid voltage changes in the electrical network negatively affects vision, which is inevitably accompanied by increased personnel fatigue and can lead to industrial injuries. The results obtained by the authors of the article show that it is possible to use it to determine the places of occurrence of large voltage fluctuations, which are manifested in unacceptable doses of flicker of the derivatives of currents. It should be taken into account when conducting surveys of power supply systems in order to use fairly simple hardware to identify sources of disturbance in the quality of electrical energy.


Author(s):  
Dmitriy Yu. Rudi ◽  
Sergey V. Gorelov ◽  
Aleksandr I. Antonov ◽  
Mikhail G. Vishnyagov ◽  
Aleksandr A. Ruppel

The importance of the problem of improving the quality of electrical energy grew along with the development and widespread introduction of various high-performance technological installations in production, such as arc steel-making furnaces, welding installations, induction furnaces, etc. in accordance with the requirements of the standard GOST 30804.4.7–2013 and in accordance with the measurement program. A method for processing the research results obtained during the experiment is described. All power quality indicators are processed using computer programs created in the Labview graphical programming environment. The analysis of indicators of the quality of electrical energy to the requirements of GOST 32144-2013 was carried out, according to the results of which conductive low-frequency electromagnetic interference was detected in the 0.4 kV electrical network according to the coefficient of the n-th harmonic voltage components. The obtained values ​​of the indicators of the quality of electrical energy, characterizing the coefficient of the n-th harmonic components of the voltage, confirm the need to use technical means to reduce the influence of higher harmonics on electrical networks.


2021 ◽  
Vol 2 (2) ◽  
pp. 29-35
Author(s):  
Dmitry A. Sorokin ◽  
◽  
Sergey I. Volskiy ◽  
Jaroslav Dragoun ◽  
◽  
...  

The paper suggests a control system of a three-phase power factor corrector. The study of the control system operation is carried out and the expressions for calculating the permissible values of error amplifier factors are obtained. The influence of the error amplifier parameters on phase current quality is investigated. The dependence of total harmonic distortion input current on a combination of error amplifier parameters is obtained at a given value of power factor. The conditions under which the total harmonic distortion input current has the minimum value are found out. This article is of interest to power electronics engineers, who are aimed at developing a three-phase power factor corrector.


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