Search results for "Power Distribution"
showing 10 items of 57 documents
Voltage Regulation and Power Losses Minimization in Automated Distribution Networks by an Evolutionary Multiobjective Approach
2004
In this paper, the problem of voltage regulation and power losses minimization for automated distribution systems is dealt with. The classical formulation of the problem of optimal control of shunt capacitor banks and Under Load Tap Changers located at HV/MV substations has been coupled with the optimal control of tie-switches and capacitor banks on the feeders of a large radially operated meshed distribution system with the aim of attaining minimum power losses and the flattening of the voltage profile. The considered formulation requires the optimization of two different objectives; therefore the use of adequate multiobjective heuristic optimization methods is needed. The heuristic strate…
Some improvements in solving radial distributions networks through the backward/forward method
2005
In the electrical radial distribution networks analysis, the backward/forward method shows good features in terms of robustness, independence from load nature, small use of hardware resources and limited calculation time. In the present paper, some procedures to improve the b/f method with the aim of reducing the calculation time are presented. The adopted procedures regard the choice of the initial values of the nodes voltages and the way in which the convergence criterion is applied. The results of some tests carried out on some electrical test systems here reported have shown the efficiency of the proposed methodology in terms of calculation time reduction, especially when solving heavil…
A new formulation of the optimal compensation and reconfiguration problem including minimum load nodes unavailability for automated distribution netw…
2004
This paper deals with a new formulation of the optimal operation of electrical distribution networks problem in regular working state. In the new deregulated energy market providing reliable and economical service to customers is a primary task. The multiobjective formulation of the reconfiguration and compensation problem used in this paper considers as a primary object also the minimisation of the load nodes unavailability (UA) expressed in probabilistic terms. Therefore, the objectives to be attained through the optimisation strategy are: minimal power losses operation, minimum UA of the load nodes, load balancing among the HV/MV transformers, and voltage profile regularisation. The appl…
Measurement uncertainty impact on simplified load flow analysis in MV smart grids
2018
This work is focused on the measurement uncertainty impact on load flow analysis in medium voltage (MV) distribution networks. In more detail, the paper presents the uncertainty evaluation of a simplified load flow algorithm, which is based on the load power measurements at each secondary substation and one voltage measurement at the slack bus (i.e. the voltage at the MV bus bars of the primary substation). To reduce the costs of the monitoring system, the load flow algorithm makes use of LV load power measurements for all the substations except those of MV users, where MV transducers are usually already installed. The uncertainties on the algorithm input quantities (load powers and slack b…
Calculations and measurements of the spectral radiance of the solar aureole
1968
The application of the theory of primary scattering to describe and interpret the spectral distribution of the sky radiance is discussed. It is shown that within the solar aureole the influence of the scattering of higher order can be neglected. Theoretical calculations of the spectral distribution of the sky radiance, carried out by Bullrich et al . (1965) based on an exponential aerosol size distribution with an upper limiting particle radius r = 10 ?, have been extended to r = 150 ?. The detailed study of the influence of these “giant” particles revealed that aerosol particles of r >30 ? have no effect on the sky radiation any more. Representative measurements taken at Mainz, Germany, at…
Continuum generation by dark solitons
2009
We demonstrate that the dark soliton trains in optical fibers with a zero of the group velocity dispersion can generate broad spectral distribution (continuum) associated with the resonant dispersive radiation emitted by solitons. This radiation is either enhanced or suppressed by the Raman scattering depending on the sign of the third order dispersion.
Spectral distribution and Coulomb correction for nuclear bremsstrahlung induced by heavy targets
2021
Abstract Bremsstrahlung spectra below 250 MeV have been measured colliding 500 MeV–electrons with Cu, Ag, and Au targets. The experimental intensity ratios relative to Cu are well described by an accurate analytical high-energy theory, which accounts both for Coulomb distortion and screening. This represents the first experimental verification of the discovery by Bethe-Maximon that leading-order quantum mechanical calculations, equivalent to quasiclassical approximations, become exact at high energies and small angles. It also shows that radiative QED effects play a minor role in the covered part of the spectral distribution within the accuracy (1.6%) of the present measurements.
Uniqueness verification of blue fraction as a parameter of spectral irradiance quantification
2021
The spectral distribution of global irradiance is measured in the optimal tilt (45° south) plane of array for the calender year 2020 in Grimstad, Norway. In this work the spectral distribution is quantified in terms of the Blue Fraction (BF). The uniqueness of BF has been tested and reported using the same methodology used for uniqueness verification of average photon energy (APE). The results show that the coefficient of correlation between the APE and BF was 0.98, meaning a possible bijective relation between these two parameters whereby both indicate a similar spectrum. The percentage contribution of integrated irradiance (Rc) was calculated for 25 nm wavelength bins for the BF region 35…
A methodology based on demand side management approaches for an optimal planning of MV-LV grid expansion in highly congested urban areas
2006
Nowadays, a renewed and growing interest is involving the Demand Side Management (DSM) techniques, since they are regarded as suitable tools in Distribution Networks planning. The following drivers trigger off this revitalisation: • The electric demand in urban contexts is growing beyond the expectations, owing to correspondingly increased needs of comfort (air-conditioning, indoor air quality, housekeeping, communication, etc.), which can be fulfilled through the electric end-uses with high quality, compliance with environmental regulations and competitive economic benefits. • This sudden higher pressure of the demand on the local Electric System is bound to force the Distributors to make …
Simple measures to improve the performances of the backward/forward method for radial distribution network analysis
2005
In the paper, after having presented the general backward/forward methodology for radial systems analysis, the main changes that have been proposed in the past to improve their convergence and speed performance are shown. Some measures aimed at a further reduction of the number of iterations and calculation times are here described. In order to identify, among the available alternatives, the best methodology, in terms of precision and/or speed of convergence, some evaluations on networks taken from the literature have been carried out. The analysis of the attained results allows the definition, on the basis of specific features of the problem at hand, the most suitable configuration to be i…