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The paper aims to analyze the effects introduced by additional equipment and consumers (AEC) over power quality indices in electric substations and general internal services from a Romanian power plant which uses solid fuel combustion. AEC includes asynchronous motors, rectifiers and frequency converters, introduced for environment protection. The measurement points are presented. Some of the most...
The present paper deals with an electricity market software package developed for educational purposes. The electricity market package presents mainly the day-ahead market and methods for the electricity consumption forecast. The simulator, designated for students, report all the steps required for generators and buyers to participate to the day-ahead market, determining the market clearing price,...
The paper emphasizes a study regarding the efficiency of the passive loops usage for the mitigation of the magnetic field values in the neighborhood of high voltage overhead power lines. In the first part of the paper the basic principles of the suppression method are introduced. In the second part of the paper analytical computation results are presented and discussed. The efficiency of the proposed...
In previous papers, the authors have resumed the earth grounding dimensioning with the intend to propose optimum criteria and to simplifying the design procedure. Five general characteristic sizes for the earth grounding have been proposed that may be in as many objective functions. Of these, the footprint area, the total metallic mass and the earth grounding volume have already been approached with...
This paper presents a design approach for renewable energy power systems operation in case of power outage or grid failure. The grid connected distributed power system delivers energy to the consumers located on the micro-grid, operating at distribution voltage level, and also delivering the remaining surplus energy to the main distribution grid. The optimal and permanent system operation is when...
Capacitor banks (CBs) are used for reactive power compensation in electricity distribution systems. In order to achieve the best effect, CBs placement requires optimization. Metaheuristic computational intelligence algorithms are methods widely used in the literature for this purpose. This paper presents a parallel Particle Swarm Optimization algorithm for bus voltage optimization. The results of...
The loadbreak cutout control is most often performed from the zonal load dispatcher level. The system presented in this paper performs the remote control and permanent monitoring of some loadbreak cutouts which run on a 20kV power line. The monitoring and control is directly carried out by the zonal load dispatcher. This remote control alternative provides more operativity and safety in decision making...
The purpose of this paper is to test the algorithm of PWM with inverter non-idealities compensation and switching losses minimization on a model with various power directions and power factor. The PWM strategy implements simultaneous switching losses minimization and dead-time and voltage drop compensation. The operation of the algorithm is considered. Collisions between switching losses minimization...
Load profiling refers to a procedure which leads to the formulation of daily load curve and consumer classes regarding the similarity of the curves shapes. This procedure incorporates a set of unsupervised machine learning algorithms. Various researches propose clustering algorithms for grouping together load curves with high degree of similarity. K-means is the most common algorithm in the load profiling...
Wind energy has become a good alternative to diversification and expansion of the Brazilian electric matrix. However, the random nature of the wind speed makes its forecast complex, directly affecting the planning and operation of generation systems. For a proper integration, it is necessary to formulate the prediction of resources available through reliable methodologies. Currently, there are several...
This paper develops a mathematical model for optimal capacitor placement and sizing in radial distribution systems. The optimization model finds placement and sizes of capacitors considering variations on load profiles with 15-minute resolution. A recently developed heuristic algorithm, Moth-flame Optimization Algorithm, is modified and used to solve the model. Optimization model is tested on a modified...
Developing offshore wind farms are becoming a more attractive solution nowadays. For preventing the changes of the climate, the world leaders have set some environmental goals, which will be difficult to reach out without RES production and the removal of production units with very high emissions. In this paper has been analyzed the possibility to install an offshore wind farm under two constructive...
The problem of reducing electricity consumption by using energy saving lamp type LED (Light-Emitting Diode), CFL (Compact fluorescent lamp) or UV (Ultra Violet) took unprecedented proportions in all EU countries. Compared to traditional incandescent lamp, the advantages of energy saving lamps in terms of efficiency that the environmental impact is undisputed. We find this type of energy saving lamps...
Distribution networks are increasingly hosting embedded generators, most of them converting renewable energy primary sources. These units are usually interfaced with the main network by means of static power converters. Grid codes have recently introduced stabilizing functions to engage distributed plants in supporting the main system stability during network events and consequent voltage/frequency...
In this article we'll tackle the control of multi-motors electric drives with high dynamic, with rapid changes in torque and speed, with flexible coupling of motors, where the control strategy is FOC (Field Oriented Control) for each drives and the distributed control in local network using the CanOpen protocol. In the surface mining industry, from which the electric drive application for this article...
This paper proposes a novel method to estimate the influence of domestic consumers on power quality, namely harmonic pollution, using fuzzy logic. Comparing the conventional measurement approach, the proposed fuzzy logic method is simpler and time saving. The fuzzy logic system used to quantify the impact on harmonic distortion, contains several modules: the fuzzifier, database, base rule and defuzzifier...
This paper examines the effectiveness of additional reactive current injection of the inverter-based distributed energy resource to mitigate short voltage instability during extreme-low voltage ride through, by studying the steady-state voltage rise effect under different X/R ratios and the effect of normal operating setting, such as unity-power factor and under-excitation. The response to the potential...
This paper aims to detail and illustrate the operation of the LEMS during the grid-connected and grid-disconnected mode of the Smart Rural Grid (SRG) project. The SRG project is focused on DSO's capabilities to increase the interoperability, resilience, efficiency and robustness of the existing rural distribution network by the utilization of new Smart Grid technologies. This project is founded by...
The paper develops a spectrum localization method for the symmetrical components of a three-phase, unbalanced systems, in non-sinusoidal regime. Spectral density of symmetrical components is determined in relation to the spectral density of the analytical signals associated to voltage and current signals of the three-phase systems. The method allows determining the direct and inverse sequence of components...
The capabilities related to active filtering of the Stationary Wavelet Transform — SWT were evaluated considering 3 Daubechy wavelet mothers. Firstly a study on errors was performed on synthetic waveforms. The waveforms were obtained from sinusoids polluted by single harmonics with orders from the range 3…40 and magnitudes, respectively phase differences varied in a systematic manner. The differences...
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