Electric Power Systems Research Research Articles

Corrigendum to ’ Voltage feasibility-constrained peer-to-peer energy trading with polytopic injection domains’[<Electric Power Systems Research, Volume 212, November 2022, 108591>

Corrigendum to ’ Voltage feasibility-constrained peer-to-peer energy trading with polytopic injection domains’[<Electric Power Systems Research, Volume 212, November 2022, 108591>

Optimal Energy Storage Systems for Long Charge/Discharge Duration

The interest for long-term energy storage in electrical grid provided with renewable energy sources is presently growing, because of the wide range of service that such systems can offer [1,2]. Although the choice of optimal duration of the charge / discharge cycles of energy storage systems for stationary applications is still an open question, among the different energy storage technologies available at a high readiness level (TRL), a few fit particularly well this kind of services [3,4]. Depending on the application and the market in which the energy storage systems are applied, the optimal duration can have different values and call for different technologies. Among electrochemical energy storage systems Vanadium Redox Flow Batteries (VRFBs) are emerging as a very promising solution for long-term stationary applications [5]. In order to find an optimal duration value for applications, the development of a physical-economic model becomes essential. Indeed, the optimal duration of energy storage systems not only depends on the technical features of each energy storage device (e.g. life cycle, self-discharge, ecc...), but also on the specific services required by the market. VRFBs devices which may be very expensive for a specific market, could be a competitive solution for a different one. The purpose of this work is to size the optimal duration of VRFB system according to the specific applications and the reference market.Reference Wu Y, Liu Z, Liu J, Xiao H, Li, R, Zhang L, Optimal battery capacity of grid-connected PV-battery systems considering battery degradation, Renewable Energy, 2022,181:10-23. DOI: 1016/j.renene.2021.09.036.Simoglou CK, Biskas PN, Marneris IG, Roumkos CG, Long-term electricity procurement portfolio optimization, Electric Power Systems Research, 2022, 202:107582. DOI: 1016/j.epsr.2021.107582Alotto P, Guarnieri M, Moro F, Redox Flow Batteries for the storage of renewable energy: a review, Renewable & Sustainable Energy Reviews, 2014,29:325-335. DOI: 1016/j.rser.2013.08.001.Ibrahim H, Ilinca A, Perron J, Energy storage systems-Characteristics and comparisons, Renewable and Sustainable Energy Reviews, 2008,12,5:1221-1250. DOI:10.1016/j.rser.2007.01.023Guarnieri M, Mattavelli P, Petrone G, Spagnuolo G, Vanadium Redox Flow Batteries: Potentials and Challenges of an Emerging Storage Technology, IEEE Industrial Electronics Magazine, 2016,10,4:20-31. DOI: 1109/MIE.2016.2611760. Figure 1

PERLINDUNGAN PETIR, SISTEM PENTANAHAN, DAN RESISTIVITAS TANAH: STUDI BIBLIOMETRIK

Increased lightning intensity generally causes an increase in the level of hazards such as infrastructure damage and death. To mitigate these hazards, research is necessary. Research developments can be seen from the various literature published in journals or books. This study aimed to quantitatively assess the development of research on lightning protection, grounding systems, and soil resistivity. The bibliometric method is used by searching based on keywords in the Scopus basis data, then visualizing it using VOSviewer. The results showed that the total identified publications were 706 publications all years, the first publication in 1967 and the highest in 2014-2020 with 481 publications (68.1%). The countries that dominate are China and Brazil. Universidade Federal de Minas Gerais was the most productive institution, while Silverio Visacro was the most productive writer. Engineering and energy are the most widely written subjects, while topics related to multidisciplinary are still rare (0.2%). Electric Power Systems Research Journal is the top journal that publishes this research topic. The publication progress map based on co-occurrences consists of 9 clusters. The few research topics include electrical safety, substation, and backfill materials, while current topics include towers, wind turbines, bentonite, natural enhancement materials, and electromagnetic models.

Scientific Errors of the Gas Model of “Multi-Time Period Combined Gas and Electricity Network Optimisation”, Doi: 10.1016/J.Epsr.2007.11.002

This paper addresses the scientific errors of the gas model developed by Chaudry et al. on Electric Power Systems Research 78 (2008) 1265–1279. The proposed gas network model of the original paper does not obey the mass and momentum equations for the (successive) steady-state conditions. To illustrate the technical flaws of the gas model, a gas pipe with a time-varying demand profile and a fixed inlet pressure was used to find the outlet pressure, gas intake, change of linepack, and flow imbalance by three methods: 1) the proposed model of Chaudry et al. for successive steady-state conditions (Method 1), 2) PipelineStudio successive steady-state (Method 2), and 3) PipelineStudio unsteady-state (Method 3). There are large deviations between the results obtained from the original paper (Method 1) and the ones from the PipelineStudio gas simulator (Method 2 and 3).

New River Light and Power Data: A Data Ecosystem for Electric Power Systems Research (I1.A4)

This article provides data useful for electric power systems research by students, faculty and the community to download or to use in a cloud-based analytics environment with state of the art analytics tools. The work includes carefully cleaning, documenting, preparing and enriching 12+ years of non-personally identifiable substation data for the 5 substations managed by New River Light and Power (NRLP), a non-profit electric utility operated by Appalachian State University's Division of Business Affairs. This data includes bulk summary data for the aggregate 8,000+ meters NRLP manages with a record of the total energy used per substation for each hour of day. This data has been enriched with matching hourly weather and solar radiation data, town daily water and sewer flows to measure town occupancy, a list of university and community events likely to influence power consumption, and a description of each substation region.

Identification of the Weakest Buses to Facilitate the Search for Optimal Placement of Var Sources Using “Kessel and Glavitch” Index

In this paper, the main objective is to identify the weakest buses in the power system in order to facilitate the search process of optimal placement of reactive power sources using “Kessel and Glavitch” voltage stability index ( $$L_{KG}$$ ). To reach our goal, particle swarm optimization algorithm (PSO) is used and has been applied to the standard IEEE 30-bus for different objectives. The obtained results have been compared to the existing papers reported in the literature. The originality of this work is the use of “Kessel and Glavitch” voltage stability index to provide to the electric power systems research field more accurate and high quality results in the optimal location search of Var supports (such as FACTS devices…etc.) in the power systems.

Comment on ‘Differential evolution technique-based short-term economic generation scheduling of hydrothermal systems’ by K.K. Mandal, N. Chakraborty Electric Power Systems Research 78 (2008) 1972–1979

This research has been developed with the aim of analyzing of the reported results in ‘Differential evolution technique-based short-term economic generation scheduling of hydrothermal systems’ by K.K. Mandal, N. Chakraborty Electric Power Systems Research 78 (2008) 1972–1979. Indeed, that optimization problem did not take into account the storage capacity of the reservoirs constraints and the positivity of the power generated by each hydro unit over the scheduling horizon.

Electric Power Systems Research

This book contains articles [1–22] that were accepted for publication in a Special Issue of Energies on the subject of “Electric Power Systems Research”.[...]

Optimisation techniques for planning automatic under frequency load shedding in New Zealand's power system

Electricity generation is vital in developed countries to power the many mechanical and electrical devices that people require. Unfortunately electricity generation is costly. Although electricity can be generated easily but not normally stored. Electricity generation is also difficult to manage because exact demand is unknown from one instant to the next. A number of services are required to manage fluctuations in electricity demand, and to protect the system when frequency falls below acceptable levels. A current approach is called automatic under frequency load shedding. This article proposes new methods for optimising this approach in New Zealand's power system. The core ideas were developed during the 2015 Maths and Industry Study Group in Brisbane, Australia. The problem was motivated by Transpower Limited, a company that manages New Zealand's power system and transports bulk electricity from where it is generated to where it is needed. The approaches developed in this article can be used in electrical power systems anywhere in the world. References Arroyo J. M. and Galiana F. D. Energy and reserve pricing in security and network constrained electricity markets. IEEE Transactions on Power Systems, 20(2):C634–C643, 2005. Burdett R. and Kozan, E. Performance profiling for predictive train schedules. Journal of Rail Transport Planning and Management, 4:C98–C114, 2014. doi:10.1016/j.jrtpm.2014.11.002. Hiscock J., Hiscock N. and Kennedy A. Advanced voltage control for networks with distributed generation. 19th International Conference on Electricity Distribution. Vienna, 21–24 May, 2007. Just S. and Weber C. Pricing of reserves. Energy Economics, 30:C3198–C3221, 2008. El-Khattam W., Bhattacharya K., Hegazy Y. and Salama M. M. A. Optimal investment planning for distributed generation in a competitive electricity market. IEEE Transactions On Power Systems, 19(3). Kusano N. New trends in protection relays and substation automation systems in Japan. Transmission and Distribution Conference and Exhibition 2002: Asia Pacific. IEEE/PES, 1, 624–628. Lopes J. A., Hatziargyriou N., Mutale J., Djapic P. and Jenkins, N. Integrating distributed generation into electric power systems: A review of drivers, challenges and opportunities. Electric Power Systems Research, 77, 1189–1203. Thomson M. Automatic voltage-control relays and embedded generation. Power Engineering Journal, April, 71–76. Wong S. and Fuller D. J. Pricing energy and reserves using stochastic optimization in an alternative electricity market. IEEE Transactions on Power Systems, 22(2), 631–638. Transpower AUFLS Summary Card. WL 13309 https://www.systemoperator.co.nz/sites/.../AUFLS_Summary_Card.pdf Transpower Electricity reserve technical requirements schedule–-ERTWG https://www.systemoperator.co.nz/sites/default/files/bulk-upload/documents/ERTWG%20Trial%20Procurement%20Schedule%20Guide.pdf AIMMS AIMMS 3.13 - AIMMS Modeling Guide - Integer Programming Tricks. http://www.aimms.com

Portfolio optimization in zonal energy markets: Evidence from Italy

International Journal of Energy and StatisticsVol. 03, No. 02, 1550006 (2015) No AccessPortfolio optimization in zonal energy markets: Evidence from ItalyEmmanuel Senyo FianuEmmanuel Senyo FianuLeuphana University Lüneburg, Scharnhorststr. 1 21335, Lüneburg, Germany Search for more papers by this author https://doi.org/10.1142/S2335680415500064Cited by:2 Next AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsRecommend to Library ShareShare onFacebookTwitterLinked InRedditEmail AbstractThis paper examines different types of optimization techniques and provides a spatial analysis of energy prices. The last decade has seen an increasing interest in deregulated energy markets. There are few papers, to the author's knowledge, that have considered portfolio optimization, however not in the Italian zonal energy market since deregulation. In deregulated energy markets with zonal pricing the market is partitioned into a number of zones, each of which is assigned a market price to which market participants react to at any given point in time. The paper investigates with emphasis on portfolio theory accounting for the initial capital requirement for the various zones in the Italian energy market and computes the optimal allocation weights needed in the various zones to mitigate the risk inherent in the market. The market risk subsequently affects the zonal prices since these prices combine to bring about the single national electricity price (prezzo unico d'acquisto, PUN). Implementing a modified version of the Mean–Variance portfolio theory, we draw policy implications based on the empirical evidence providing good risk management strategy for market participants.Keywords:Electricity spot pricesportfolio theoryportfolio optimizationzonal pricing References H. M. Markowitz, Journal of Finance 7(1), 77 (1952). Crossref, Google Scholar H. M. Markowitz , Portfolio Selection: Efficient Diversification of Investments ( John Wiley & Sons , New York , 1959 ) . Google ScholarW. Sharpe, The Journal of Finance 19(3), 425 (1964). Crossref, Google ScholarJ. Lintner, The Review of Economics and Statistics 47(1), 13 (1965). Crossref, Google ScholarD. Bar-Lev and S. Katz, The Journal of Finance 31(3), 933 (1976). Crossref, Google ScholarH. Humphreys and K. McClain, The Energy Journal 19(3), 107 (1998). Google Scholar Awerbuch, S. and Berger, M. (2003). Energy security and diversity in the EU: A mean-variance portfolio approach. IEA Research Paper . Google ScholarL. Marzano, A. Melo and R. Souza, An approach for portfolio optimization of energy contracts in the brazilian electric sector, In: 2003 IEEE Bologna Power Tech Conference Proceedings (2003) p. 3. Google ScholarZ. Yu, Energy Economics 25(3), 255 (2003). Crossref, Google ScholarZ. Yu, International Journal of Electrical Power & Energy Systems 29(8), 600 (2007). Crossref, Google ScholarF. Roques, D. Newbery and W. Nuttall, Energy Economics 30(4), 1831 (2008). Crossref, Google Scholar L. Grossi and F. Laurini , Advances in Data Analysis and Classification 1 ( 2011 ) . Google Scholar M. Bjørndal and K. Jørnsten , The Energy Journal 51 ( 2001 ) . Google Scholar Villumsen, J. (2011). Modelling zonal pricing design under uncertainty in electricity markets. Technical Report, DTU Management . Google Scholar Á. Lorca and J. Prina , Electric Power Systems Research 109 , 80 ( 2014 ) . Crossref, Google ScholarR. Rockafellar and S. Uryasev, Journal of Banking & Finance 26(7), 1443 (2002). Crossref, Google Scholar F. Boffa and V. Pingali , Unpublished Manuscript ( 2006 ) . Google ScholarE. Guerci and A. Sapio, Revue de l'OFCE 124(5), 415 (2012). Crossref, Google ScholarA. Gaivoronski and G. Pflug, Journal of Risk 7(2), 1 (2005). Crossref, Google Scholar S. T. Rachev , S. V. Stoyanov and F. J. Fabozzi , Advanced Stochastic Models, Risk Assessment, and Portfolio Optimization: The Ideal Risk, Uncertainty, and Performance Measures ( John Wiley & Sons , New York , 2008 ) . Google ScholarS. Korkmaz, D. Goksuluk and G. Zararsiz, The R Journal 6(2), 151 (2014). Crossref, Google Scholar Remember to check out the Most Cited Articles! Check out these titles in energy issues! FiguresReferencesRelatedDetailsCited By 2Modeling risk contagion in the Italian zonal electricity marketEmmanuel Senyo Fianu, Daniel Felix Ahelegbey and Luigi Grossi1 Apr 2022 | European Journal of Operational Research, Vol. 298, No. 2A Network Framework of Investigating Systemic Risk in Zonal Energy MarketsEmmanuel Senyo Fianu and Luigi Grossi1 Jan 2016 | SSRN Electronic Journal, Vol. 105 Recommended Vol. 03, No. 02 Metrics History Received 27 January 2015 Revised 28 February 2015 Accepted 3 March 2015 Published: 30 June 2015 KeywordsElectricity spot pricesportfolio theoryportfolio optimizationzonal pricingPDF download

Discussion on “Short-term environmental/economic hydrothermal scheduling”

This short communication is a discussion of the paper entitled “Short-term environmental/economic hydrothermal scheduling” by Mohammad Reza Norouzi, Abdollah Ahmadi, Adel M. Sharaf, and Ali Esmaeel Nezhad published in the Electric Power Systems Research 116 (2014) pp. 117–127. In the discussed paper, the results presented in Tables 2, 3, 5 were different from what we have calculated, which we believe is correct. Here, we present the correct results in detail.

Comments on “Adaptive sliding mode observer for induction motor using two-time-scale approach”

This short communication is a discussion of the paper entitled “Adaptive sliding mode observer for induction motor using two-time-scale approach” by A. Mezouar, M.K. Fellah and S. Hadjeri published in the Electric Power Systems Research 77 (2007) pp. 604–618. In the discussed paper the authors present a current and flux sliding mode observer for the induction motor that also incorporates an adaptive law in order to estimate the inverse of the rotor time constant. However the proposed observer design uses the real value of the rotor time constant which is unknown and therefore cannot be used in the observer design.

Long-Term Aging Mechanisms in Li-Ion Batteries for Renewable Energy Storage

The development of renewable energies such as photovoltaic or wind energy is strongly conditioned by the intermittent nature of these energy sources, often making the production and consumption periods time-shifted. Therefore, the efficiency of energy storage is of first importance to manage the mismatch between energy production and consumption. Li-ion technology is a good candidate to fulfill this task [1], but this kind of application requires much longer battery lifetimes than other applications such as mobile electronic devices or electric vehicles. Indeed, batteries performances shall be preserved for up to 20 years, which is twice as much as the current commercial applications for EV/HEVs.This work aims at describing the long time aging processes of a Li-ion battery. We focused on aging mechanisms occurring at interfaces between electrodes and electrolyte, which are a key parameter for the retention of battery performances over time. We studied Li-ion cells composed of a lamellar oxide NMC Li(NixMnyCo1-x-y)O2positive electrode and a graphite negative electrode. These cells were submitted to accelerated aging tests to simulate a long cycle or calendar life: high rate cycling tests at room temperature or storage at 60°C in charged state at 4.1V. In this experimental approach, aged electrodes were analyzed by X-ray Photoelectron Spectroscopy (XPS) and Electrochemical Impedance Spectroscopy (EIS) which provide complementary information about interfaces.Post-mortem characterisation of aged cells highlighted the surface degradation of the NMC active material after intense cycling. From XPS data this degradation is revealed by a change of the layered oxide surface stoichiometry: (i) the Ni/Mn/Co ratio is different form the pristine positive material and (ii)the presence of these three metals is observed at the surface of the negative electrode (see Fig.1) with a larger amount than commonly observed [2].This demonstrates the enhanced dissolution process of the metals at the surface of the active material in the electrolyte. Moreover, XPS analyses also provided information about the composition of the passivation films at the surface of both electrodes considering the aging conditions.Additionally, Electrochemical Impedance Spectroscopy (EIS) revealed that calendar ageing leads to the formation of a more resistive passivation film than cycling ageing at the surface of the positive electrodes. This means that the passivation layer at the surface of the positive electrodes is thicker (or denser) after a long storing period than after long cycling. EIS spectra of negative electrodes display distorted profiles as shown in Fig. 2 due to the samples porosity. Taking into account the porosity was necessary to establish correct equivalent electrical circuits modeling the electrode behavior. This leads to complex circuits using transmission lines based on the DeLevie model [3]. The evolution of samples porosity was studied in parallel with BET measurements in order to validate the associated models.A new generation of prototype cells was developed afterwards. Results show that they have a better aging behavior. The modification of the positive electrode allowed a drastic capacity fading reduction upon cycling. Passivation layers have also been impacted by the operated modifications. O 1s XPS core peaks revealed that the cathode passivation film is thinner. Moreover, the active material degradation is lowered in these new cells.[1] K.C. Divya, J. Østergraad, Electric Power System Research, 79(2009) 511-520[2] S. Verdier, L. El Ouatani, R. Dedryvère, F. Bonhomme, P. Biensan, D. Gonbeau, J. Electrochem. Soc., 154(2007) A1088-A1099[3] O.E. Barcia, E. D'Elia, I. Frateur, O.R. Mattos, N. Pebere, B. Tribollet, Electrochimica Acta, 47(2002) 2109-2116Aknowledgement: This work was funded by ANR (Agence Nationale de la Recherche) and is part of the VISION project.

Discussion of “Combined heat and power economic dispatch problem solution using particle swarm optimization with time varying acceleration coefficients” by Mohammadi-Ivatloo et al. “Electric Power Systems Research” 95 (2013) 9–18

The recent paper [Combined heat and power economic dispatch problem solution using particle swarm optimization with time varying acceleration coefficient by Mohammadi-Ivatloo et al., Electric Power Systems Research 95 (2013) 9–18] presented CHPED problem by experimenting with five test systems considering valve-point loading effects and transmission losses. In this short discussion we point out that some results of the discussed paper for case III are affected by imprecision as some system test data have been mis-reported. In this discussion, the corrected data of the test system III and clarifications regarding generation cost and power transmission losses are presented.

Discussion of “Solving non-convex economic dispatch problem with valve point effects using modified group search optimizer method” by Kazem Zare et al. “Electric Power Systems Research” 84 (2012) 83–89

This short communication presents a discussion of “Solving non-convex economic dispatch problem with valve point effects using modified group search optimizer method” by Kazem Zare et al. “Electric Power Systems Research” 84 (2012) 83–89. The discussed paper presented economic dispatch problem by experimenting with three example systems considering 3, 13 and 40-unit test systems considering nonconvex cost function with valve point loading effects. However, in the reported results for the 13-unit test system with two different load demands, the total costs quoted were different for the given generation schedule. In this communication, clarification regarding cost calculations is presented.

A Bibliographic Analysis of Transformer Literature 1990-2000

This paper presents an analysis of the bibliography on transformers covering the period from 1990 to 2000. It contains all the transformer subjects: a) Transformer design, b) Transformer protection, c) Transformer connections, d) Transformer diagnostics, e) Transformer failures, f) Transient analysis of transformers (overvoltages, overcurrents), g) Modeling and analysis of transformer using FEM (thermal modeling, losses modeling, insulation modeling, windings modeling). Several international journals were investigated including the following: Advances in Electrical and Computer Engineering, Canadian Journal of Electrical and Computer Engineering, COMPEL (The International Journal for Computation and Mathematics in Electrical and Electronic Engineering), Electrical Engineering, Electric Power Components and Systems, Electric Power Systems Research, European Transactions on Electrical Power, IEEE Transactions on Magnetics, IEEE Transactions on Power Delivery, International Journal of Electrical Power and Energy Systems, and IET Generation Transmission & Distribution. Due to the high number of publication in journals, we are not considering publications of conferences and symposia. A total of 700 publications are analyzed in this paper. The research presented in this paper is important because it contains and analyzes the best research papers on transformers coming from many countries all over the world and published in top rated scientific electrical engineering journals.

An extended interpretation of THD concept in the wake of ship electric power systems research

The paper is to investigate seemingly a simple problem of THD interpretation in the wake of standards’ definitions and measurement methods. The consequences of application of various definitions of the considered factor are profoundly discussed on the basis of the real voltage waveforms registered in two different ship systems. Particularly, the results of determining of THD by means of various definitions are presented. Finally, the proposed amendment of related rules is provided. The aim is to overcome hitherto existing ambiguities.

Application of Phasor Measurement Unit on Locating Disturbance Source for Low-Frequency Oscillation

A smart power grid is an integration of the advanced measurement, communication, computer, and control techniques. Among all the state-of-the-art technologies in building a smart power grid, the phasor measurement unit (PMU) is an important and promising one. Nowadays in China, most ultrahigh- and high-voltage buses are all equipped with PMUs. This paper reports an application of PMU data on locating the disturbance source for the low-frequency oscillation that has happened several times in the interconnected big power grids in China recently. The posterior analysis by the Electric Power System Research Institute of China (CEPRI) has confirmed that these low-frequency oscillations are caused by the resonance phenomena. It is urgent to find the disturbance source in case it happens again. However, there have been no systematic and effective methods to locate the disturbance in a very large power system. The trial and error method has been implemented via the digital simulations, but in vain. To overcome this problem, a novel method is developed in this paper to locate the disturbance source with the help of PMUs. The method takes advantage of the PMU measurements to reduce the searching area for locating the disturbance source. Case studies show the efficiency of the proposed method.

Notice of Violation of IEEE Publication Principles: Optimal Cost-Benefit for the Location of Capacitors in Radial Distribution Systems

Notice of Violation of IEEE Publication Principles<br><br>"Optimal Cost-Benefit for the Location of Capacitors in Radial Distribution Systems"<br>by H.M. Khodr, Zita A. Vale, Carlos Ramos<br>in the IEEE Transactions on Power Delivery, Vol 24, No 2, April 2009<br><br>After careful and considered review of the content and authorship of this paper by a duly constituted expert committee, this paper has been found to be in violation of IEEE's Publication Principles.<br><br>This paper was found to be a near verbatim copy of the paper cited below. The original text was reused without appropriate attribution to the original publication, nor to the coauthors of the original paper.<br><br>Due to the nature of this violation, reasonable effort should be made to remove all past references to this paper, and future references should be made to the following paper:<br><br>"Maximum Savings Approach for Location and Sizing of Capacitors in Distribution Systems"<br>by H.M. Khodr, F.G. Olsina, P.M. De Oliveira-De Jesus, J.M. Yusta,<br>in Electric Power Systems Research, 78 (2008), Elsevier, pp. 1192-1203<br><br> <br/> This paper proposes a computationally efficient methodology for the optimal location and sizing of static and switched shunt capacitors in radial distribution systems. The problem is formulated as the maximization of the savings produced by the reduction in energy losses and the avoided costs due to investment deferral in the expansion of the network. The proposed method selects the nodes to be compensated, as well as the optimal capacitor ratings and their operational characteristics, i.e., fixed or switched. After an appropriate linearization, the optimization problem was formulated as a mixed-integer linear problem, suitable for being solved by means of a widespread commercial package. Results of the proposed optimizing method are compared with another recent methodology reported in the literature using two test cases: a 15-bus and a 33-bus distribution network. For both cases tested, the proposed methodology delivers better solutions indicated by higher losses savings, which are achieved with lower amounts of capacitive compensation. To calculate exactly the energy savings and the deferral investment cost, a power flow for radial distribution networks is executed before and after the compensation. The proposed method has also been applied for compensating an actual radial distribution network served by AES-Venezuela in the metropolitan area of Caracas. A convergence time of about 4 s after 22\thinspace 298 iterations demonstrates the ability of the proposed methodology for efficiently handling compensation problems.

06/02370 A new method for measurement of harmonic groups in power systems using wavelet analysis in the IEC standard framework: Barros, J. and Diego, R. I. Electric Power Systems Research, 2006, 76, (4), 200–208.

06/02370 A new method for measurement of harmonic groups in power systems using wavelet analysis in the IEC standard framework: Barros, J. and Diego, R. I. Electric Power Systems Research, 2006, 76, (4), 200–208.