This paper proposes an alternative to solve the distribution network reconfiguration (DNR) problem, aiming real power losses' minimization. For being a problem that has complexity for its solution, approximate techniques are adequate solving it. Here, proposition is technique based on firefly metaheuristic, named selective algorithm, where positioning of these insects compressed in range values. The algorithm applied DNR, and all implementation adequacy studied presented. To define search...

This paper proposes a novel controller optimization of boost converter by tunning two controllers voltage and current in PV (Photovoltaic) converters: Sliding Mode Control (SMC) or plus Proportional-Integrative. Genetic Algorithm (GA) is applied Internet Things (IoT) context, which the server side consists running GA thereafter used to tune SMC SMPIC plant converter. Communication between IoT (PV plant) cloud comprises acquired currents voltages from parameters IoT. Data calculate fitness...

The aims of this study were to investigate work conditions, estimate the prevalence and describe risk factors associated with Computer Vision Syndrome among two call centers' operators in São Paulo (n = 476). methods include a quantitative cross-sectional observational an ergonomic analysis, using observation, interviews questionnaires. case definition was presence one or more specific ocular symptoms answered as always, often sometimes. multiple logistic regression model, created stepwise...

This paper proposes a robust finite control set for doubly-fed induction generator power control. In this way, the proposed has two components of predicted rotor voltage. The first term calculates voltage considering current references and second is designed mistakes due to parameters' estimation. mentioned errors variations were modeled as changes. Hence, controller parameter references. So that, minimized cost function selects vector be supplied machine. influence estimation on...

An estimation procedure for transmission line parameters is developed that combines a new method of determining with others available in the technical literature. Each has certain advantages and restrictions depend on operating conditions system (e.g. load profile), physical characteristics length geometry) electromagnetic phenomena single‐ or multiphase faults). The proposed exploits major attributes both determination this study other well‐established methods previously presented Based...

Virtual power plant (VPP) interconnects distributed generation (DG) units, microgrids, and energy storage systems (ESSs) of an electrical system. This article presents a linear programming cost minimization model VPP for the design commitments DG, ESS, microgrid. Using set renewable resources, proposed creates reliable, cost-effective, environmentally friendly distribution Accurately, it illustrates schedule to operate autonomously. The is applied United States commercial load profiles...

Abstract The previous knowledge of the admittance matrix represents an important issue in power system analysis, specifically regarding load flow, voltage stability, and protection setting. Some parameter estimation techniques technical literature determine electric grids, leading to notable advances measurement monitoring. This paper proposes a robust approach using deep learning techniques. Throughout paper, results demonstrate that proposed handles Gaussian non‐Gaussian noise reliably,...

The genus Jacaranda Juss. (Bignoniaceae) is native to Central and South America are known have antioxidant, antimicrobial anticancer activities. This study aimed identify phenolic flavonoid compounds from leaves twigs of three species the using HPLC-DAD-MS, ESI-MS Tandem MS (ESI-MS/MS), as well evaluate inhibitory activity extracts on enzyme acetylcholinesterase. Leaves caroba, mimosifolia oxyphylla were dried subjected extraction with hexane, chloroform methanol obtain crude extracts. In...

Operation of distribution networks involves a series criteria that should be met, aiming for the correct and optimal behavior such systems. Some major drawbacks found when studying these is real losses related to them. To overcome this problem, network reconfiguration (DNR) an efficient tool due low costs involved in its implementation. The majority studies regarding subject treat problem by considering only as three-phase balanced, modeled single-phase grids with fixed power demand, which...

Dynamic rating of the transformer is a promising technology, which suitable for various applications. Using dynamic connecting renewable energy believed to be beneficial economy and flexibility power system. However, safely deploy such operation strategies, it important have more precise estimates total costs owning units determine how effective method solar plant. This study proposes calculating ownership (TOC) dynamically rated transformers used connection plant grid as well analyzes its...

This paper proposes a methodology for modeling and simulating electromagnetic transients in power transmission cables with arbitrary cross-sections, usually applied offshore variable speed machine drive. way, sector-shaped cable is modeled taken into account its frequency-dependent parameters. Both impedance admittance parameters are calculated by using the Finite Element Method, without analytic formulations based on approach an equivalent cylindrical cross-section, which leads to several...

This paper presents a hybrid way mixing time and frequency domain for transmission lines modelling. The proposed methodology handles steady fundamental signal mixed with fast slow transients, including impulsive oscillatory behaviour. A line model is developed based on lumped elements representation state-space techniques. represents an easy practical procedure to three-phase directly in domain, without the explicit use of inverse transforms. takes into account frequency-dependent parameters...

This study presents a simplified formulation to calculate the skin effect on transmission lines wires. The methodology is developed from solution of time‐domain Maxwell's wave equations whose frequency‐domain solutions are obtained using Fourier transforms. Results proposed compared with those calculated conventional method based approach by Bessel functions. skin‐effect also validated electromagnetic transients simulations in time domain considering 69‐kV system.

The parameter estimation for transmission systems is important to power flow analysis, planning the expansion of electric systems, stability, dispatch and economic analysis. This type task developed through identification methods, being least squares method its variations most common techniques obtain line parameters. However, these have some disadvantages, such as non-recursive or availability an ideally transposed line, in order address a problem with symmetric matrices, which simplifies...

The accurate knowledge of the electrical parameters transmission lines is an important issue for, e.g., fault detection and location, stability analysis. In this sense, reliability in which such are determined shows to be crucial entire system operation. article, we propose estimation both phasors through a nonlinear approach by using Kronecker product, order determine Jacobian terms, thereafter extended Kalman filter (EKF). carried out recursively <inline-formula...

An efficient and simplified procedure is proposed for the reduction of high‐frequency oscillations erroneous magnitude peaks in electromagnetic transient simulations power transmission systems modelled by lumped electric parameters approach. This consists inclusion analogue filters equivalent representation multiconductor lines without modifying its propagation characteristics. The filter modelling conducted as a function line length parameters. simulation methodology applied directly...

This paper proposes a complete and novel approach for estimation of impedance admittance parameters transmission lines from phasorial voltage current measurements. The work uses the rigorous modeling noise on measurements, solution is obtained based nonlinear problem. distortion introduced into classical model noisy data analyzed by using statistical techniques. Finally, performance method studied considering various load conditions, time-varying loads, number samples, proposed shows high...

Abstract This article proposes a frequency-dependent transmission line model based on state-space techniques. To include the frequency effect associated with distributed parameters in state matrices, longitudinal are fitted by rational function and then introduced lumped elements representation an equivalent RL circuit; this procedure is known as vector fitting. Subsequently, system of ordinary differential equations that represents transients currents voltages three-phase represented space....