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Article
Publication date: 14 July 2022

Oleksii V. Bialobrzheskyi and Dmytro Rod'Kin

The purpose of this paper is to identify on the instantaneous electrical power basis of a nonsinusoidal periodic current three-phase asymmetric system, active and reactive…

54

Abstract

Purposes

The purpose of this paper is to identify on the instantaneous electrical power basis of a nonsinusoidal periodic current three-phase asymmetric system, active and reactive positive, negative and zero sequence powers, taking into account higher harmonics. The main power theories, including those embodied in the IEEE 1459 standard, do not allow to evaluate some of power components.

Design/methodology/approach

A well-known fact is that the three-phase AC system total power with the symmetry of currents and voltages is constant. It corresponds to the electrical energy transfer process in a DC system. In this case, the electrical energy transmission can be taken as high quality. It has been established that the components of active and reactive powers are because of the product of current and voltage of unidirectional sequences. The orthogonal components of the oscillating power are because of the product of the voltage and current components of different sequences, with the exception of the zero sequence.

Findings

For an unbalanced nonsinusoidal mode of a three-phase system, the components of instantaneous power were defined, corresponding to the active and reactive positive and negative and zero sequences powers with the selection of the fundamental and higher harmonics. The active and reactive powers of sequences were divided into two categories – consumed and generated.

Originality/value

It is proposed to use the ratio of “interfere” power RMS value to the total power RMS value to assess the instantaneous power distortion.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 42 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 12 April 2022

Jingbo Zhao, Yan Tao and Zhiming Sun

This paper aims to clarify voltage sourced converter’s (VSC’s) influence rules on the alternating current (AC) short-circuit current and identify the key factors, so as to propose…

131

Abstract

Purpose

This paper aims to clarify voltage sourced converter’s (VSC’s) influence rules on the alternating current (AC) short-circuit current and identify the key factors, so as to propose the short-circuit current suppression strategy.

Design/methodology/approach

This paper investigates the key factors which impact the short-circuit current supplied by the VSC based on the equivalent current source model. This study shows that the phase of the VSC equivalent current source is mainly affected by the type of fault, whereas the amplitude is mainly decided by the control mode, the amplitude limiter and the electrical distance. Based on the above influence mechanism, the dynamic limiter with short-circuit current limiting function is designed. The theoretical analysis is verified by simulations on PSCAD.

Findings

The short-circuit current feeding from VSC is closely related to the control mode and control parameters of the VSC, fault type at AC side and the electrical distance of the fault point. The proposed dynamic limiter can make VSC absorb more reactive power to suppress the short-circuit current.

Research limitations/implications

The dynamic limiter proposed in this paper is limited to suppress three-phase short-circuit fault current. The future work will focus more on improving and extending the dynamic limiter to the fault current suppression application in other fault scenarios.

Practical implications

The research results provide a reference for the design of protection system.

Originality/value

The key influence factors are conducive to put forward the measures to suppress the fault current, eliminate the risk of short-circuit current exceeding the standard and reduce the difficulty of protection design.

Details

Circuit World, vol. 49 no. 4
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 2 May 2018

Venkataramana Veeramsetty, Venkaiah Chintham and Vinod Kumar D.M.

The purpose of this paper is to estimate the locational marginal price (LMP) at each distributed generation (DG) bus based on DG unit contribution in loss reduction. This LMP…

Abstract

Purpose

The purpose of this paper is to estimate the locational marginal price (LMP) at each distributed generation (DG) bus based on DG unit contribution in loss reduction. This LMP value can be used by distribution company (DISCO) to control private DG owners and operate network optimally in terms of active power loss.

Design/methodology/approach

This paper proposes proportional nucleolus game theory (PNGT)-based iterative method to compute LMP at each DG unit. In this algorithm, PNGT has been used to identify the share of each DG unit in loss reduction. New mathematical modeling has been incorporated in the proposed algorithm to compute incentives being given to each DG owner.

Findings

The findings of this paper are that the LMP and reactive power price values for each DG unit were computed by the proposed method for the first time. Network can be operated with less loss and zero DISCO’s extra benefit, which is essential in deregulated environment. Fair competition has been maintained among private DG owners using the proposed method.

Originality/value

PNGT has been used for the first time for computation of LMP in distribution system based on loss reduction. Incentives to each DG unit has have been computed based on financial savings of DISCO due to loss reduction. Share of active and reactive power generation of each DG unit on change in active power loss of network due to that DG unit has been computed with new mathematical modeling. The proposed method provides LMP value to each DG unit in such a way that the network will be operated with less loss.

Details

International Journal of Energy Sector Management, vol. 12 no. 3
Type: Research Article
ISSN: 1750-6220

Keywords

Article
Publication date: 3 May 2013

Gheorghe Grigoras and Gheorghe Cartina

The purpose of this paper is to introduce a method based on the fuzzy correlation for modelling of active and reactive powers from the substations of the electrical distribution…

Abstract

Purpose

The purpose of this paper is to introduce a method based on the fuzzy correlation for modelling of active and reactive powers from the substations of the electrical distribution systems, at the peak load.

Design/methodology/approach

Based on the correlation theory, the fuzzy models of the loads can be obtained using a new algorithm. If in the case of the principal/connection station there is sufficient database information for a good forecasting of the load, then for those substations where data are missing (there is no continuous monitoring or the measuring system can be broken for a while) the forecasting of the load can be performed using the correlation studies. The starting point of the algorithm is statistical analysis of the active and reactive curves of the substations and utilization of a fuzzy linear regression model. This can be made for different time windows (window 24 h, window 7 h, etc). The window 24 h can be used successfully to estimate the hourly load on any substation. The other time window (7 h) can be used in the peak load estimation of the substations, using the maximum value of the active power recorded in a reference substation.

Findings

The numerical data show that the fuzzy correlation models can be used with very good results for determination of the peak load corresponding distribution substations, and further with the state estimation of the system. In this study, the influence of the time window size is presented in detail, and the fuzzy correlation models for the peak loads from the distribution substations are obtained.

Originality/value

Starting from the correlation theory, a method of fuzzy modelling of active and reactive powers from the substations of an electrical distribution system is proposed.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 32 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 2 May 2017

Jacek Klucznik, Zbigniew Lubosny, Krzysztof Dobrzynski, Stanislaw Czapp, Robert Kowalak, Robert Trebski and Stanislaw Pokora

The paper aims to discuss problems of power and energy losses in a double-circuit overhead transmission line. It was observed from energy meters’ readings, that in such a line…

Abstract

Purpose

The paper aims to discuss problems of power and energy losses in a double-circuit overhead transmission line. It was observed from energy meters’ readings, that in such a line, active power losses can be measured as “negative”. The “negative” active power losses appear when the active power injected to the circuit is lower than the active power received at the circuit end. The purpose of this paper is to explain this phenomenon.

Design/methodology/approach

Theoretical considerations based on mathematical model of the transmission line of π-type confirming that effect are presented. Power losses related to series impedance of the line and to shunt admittance are calculated. The theoretical considerations are confirmed by measurements done on the real transmission line.

Findings

The calculations allow to indicate components of the active power losses, i.e. related to electromagnetic coupling among wires of a given circuit, related to electromagnetic coupling between circuits and related to shunt capacitance asymmetry. The authors indicate the influence of the line/wires geometry on the active power losses in a double-circuit overhead transmission line.

Originality/value

Explanation of the effect of “negative” active power losses’ measurement in a double-circuit overhead transmission line is provided in this paper.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 36 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 5 July 2013

Michał Gwóźdź

The aim of the research was to find a structure of the power electronics controlled current source with extended pass band, which would better match a source output current within…

Abstract

Purpose

The aim of the research was to find a structure of the power electronics controlled current source with extended pass band, which would better match a source output current within an input (reference) signal. Also, pulse modulation components in output current of current source should be minimized.

Design/methodology/approach

The power electronics controlled current source utilizes both, the concept of the inductor with variable (controlled) inductance located at the output of an inverter and the concept of the multi‐channel (interleaved) inverter. The small signal (linear) and simulation models of an active filter have been investigated.

Findings

The work presents the concept of 1‐phase active shunt filter with utilization of the power electronics current source about extended pass‐band.

Research limitations/implications

The research should be continued to achieve stability of the electrical system with variable parameters of the power network and receiver.

Practical implications

The research will be continued towards realization of a laboratory model of a 3‐phase active shunt filter with the DSP based control module.

Social implications

Social implications are difficult to determine.

Originality/value

The paper presents a new concept of the precision power electronics controlled current source with the extended pass‐band. The controlled current source is the fundamental block of a power electronics active shunt filter.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 32 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 9 November 2012

Daniel Wojciechowski

The purpose of this paper is to present the concept and design methodology for unified, LCL interfacing circuit intended for a high power, modular active power filtering system…

Abstract

Purpose

The purpose of this paper is to present the concept and design methodology for unified, LCL interfacing circuit intended for a high power, modular active power filtering system. The paper aims to contain simulations and selected measurements of an industry applied system.

Design/methodology/approach

The design methodology of unified LCL circuit is based on an analytical model of the system and practical requirements for an active power filter. The stability of the system is confirmed by using poles of discrete transmittance of the close loop system.

Findings

The paper reveals the topology and design methodology of the unified LCL circuit for a high power, modular active power filtering system. The circuit permits zero current ripples, high dynamics of compensating currents, and full scalability of the system.

Practical implications

The practical implications of this paper are in the industrial applications of high power, modular active filtering system.

Originality/value

The topology of unified LCL filter and its design methodology for a modular active power filtering system are of value. It also provides a stability analysis for the system with model‐based predictive current controller.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 31 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 February 2022

Oleksii V. Bialobrzheskyi, Dmytro RodKin and Andrii Gladyr

At the current stage of electrical technology development, it is relevant to take into account the quality of electrical energy. It can be implemented if an assessed energy…

Abstract

Purpose

At the current stage of electrical technology development, it is relevant to take into account the quality of electrical energy. It can be implemented if an assessed energy quality indicator is available. The amount of electrical energy is determined by active power, which is transmitted over a certain time period. In some cases, reactive power is included in the metering system. The distortion power is justifiably criticized and is not taken into account. The purpose of this paper consists in the substantiation of the indicator of the distortion of the periodic polyharmonic current electrical energy power, by separating from the instantaneous power such harmonics, which formed by same frequencies current and voltage harmonics.

Design/methodology/approach

Using the method of calculating linear polyharmonic current circuits, the following quantities are identified in instantaneous power: active, reactive and apparent powers of each harmonic. These components are known from references as canonical.

Findings

By the method of instantaneous power harmonic analysis, the components formed by current and voltage harmonics of the same frequency and different frequencies are distinguished.

Research limitations/implications

The RMS value of the instantaneous power due to current and voltage harmonics of different frequencies is justified in the work. This quantity allows you to distinguish the instantaneous power distortion level in comparison with the existing quantity.

Practical implications

The results can be used to assess the level of instantaneous power distortion level in commercial and technical metering systems.

Originality/value

The definition of instantaneous power distortion by extracting the canonical components from it and determining the root mean square value of the remainder is proposed.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 41 no. 4
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 20 September 2019

Ali Zafari, Mohammad Firoozian, Seyyed Jafar Fazeli Abelouei and Ahmad Azadi Hematabadi

Votage source converter (VSC) based or current source converter (CSC) based shunt active power filter (SAPF)? It is the main question in harmonic elimination project using…

Abstract

Purpose

Votage source converter (VSC) based or current source converter (CSC) based shunt active power filter (SAPF)? It is the main question in harmonic elimination project using SAPF.This paper presents some criteria based on which the designer can decide which type of filter is more suitable for implementation of the project according to the nature and characteristics of the project.

Design/methodology/approach

Owing to the importance of cost and power losses criteria, relevant equations will be formulated and comparative analysis will be carried out between conventional structures based on CSC or VSC. For validation of analyses, simulation results have been studied in the MATLAB–SIMULINK environment.

Findings

Simulation results have examined two important criteria of power losses and costs. Although the results show the superiority of VSSAPF to CSSAPF in both criteria, this comparison is performed in a general and conventional condition. Using third-order filters of inductive-capacitive-inductive (LCL) type in VSSAPF, using insulated-gate bipolar transistor (IGBT) with reverse-voltage blocking ability in CSSAPF, which eliminates the need to use series diodes, and the use of superconducting technology in the DC-side endpoint in CSSAPF, not only reduce the difference of cost and losses in two schemes but also may lead to the lower costs and losses in CSSAPF than VSSAPF.

Originality/value

This paper is the result of many years working on active power filter and can be useful for engineers who are engaged in industrial projects.

Article
Publication date: 8 August 2019

Ali Teta, Abdellah Kouzou and Mohamed Mounir Rezaoui

This paper aims to propose a new configuration of a shunt active power filter (SAPF) connected with a photovoltaic (PV) system through a Z-source inverter (ZSI) topology. This…

Abstract

Purpose

This paper aims to propose a new configuration of a shunt active power filter (SAPF) connected with a photovoltaic (PV) system through a Z-source inverter (ZSI) topology. This topology ensures a single-stage operation and overcomes the limitations of the conventional two-stage operation topologies based on the DC–DC boost converter. The proposed system is designed for the purpose of reducing the total harmonic distortion of the source current by eliminating the current harmonics and exploiting the solar irradiation.

Design/methodology/approach

First, all the main parts of the proposed shunt active power filter are fully described in this paper, and then a PV system based on a Z-source inverter with a maximum power point tracking controller is used to exploit the solar irradiance and solve the problem of discharging of the direct current (DC) capacitor during the filtering process.

Findings

From the extensive simulation tests carried out using MATLAB/Simulink, the obtained results prove that the proposed shunt active power filter performs well despite several operation scenarios, including different load types and under abrupt irradiance.

Originality/value

A new shunt active power filter configuration has been proposed. This configuration benefits from the solar irradiation and overcomes the drawbacks of the conventional configurations by using the Z-source inverter instead of the voltage source inverter and DC–DC boost converter.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 38 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

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