MATLAB-based software for Size-Specific Dose Estimation (SSDE) in Computed Tomography Examinations

Primary and widely in use Computed Tomography (CT) dose descriptor is a volumetric CT Dose Index (CTDIv) that is usually measured by a pencil ionization chamber with active length of 100mm and polymethyl methacrylate (PMMA) phantom. CTDIv depends on scan parameters such as mAs, kV, collimation, tube rotation time but is independent of patient’s size and shape. For the purpose of a good estimation of dose received by the patients, American Association of Physicists in Medicine (AAPM) published the conversion factors for both 16 and 32cm (head and body phantoms respectively); through this, users can extract conversion factors according to lateral (LAT) and/or anterior-posterior (AP) sizes and calculate real CTDIv. Since this procedure is time consuming, we designed MATLAB-based software to reduce such calculations. To design the software, GUI toolbar of MATLAB software was used. To test the software, scan parameters of two patients for head and pelvis scan were read from PACS and lateral (LAT) and anterior-posterior (AP) sizes were measured. Finally, SSDEs were calculated for two patients by the software. The software can be measured based on AP and/or LAT measures and/or in special cases (under the age of 18) through patients' age

POVIX: una interfaz gráfica de usuario (GUI) en MatLab para calcular el polinomio de Villarreal

El matemático peruano Federico Villarreal en 1879 propuso una fórmula para calcular la potencia n-ésima de un polinomio P(x), denominado polinomio de Villarreal. El objetivo del presente trabajo fue crear una interfaz gráfica para usuario que nos permita calcular la potencia n-ésima entera de un polinomio, a partir de la fórmula propuesta por el científico. Se elaboró una interfaz gráfica de usuario denominada (POVIX), para ello se utilizó la herramienta matemática MatLab v9.2 (R2017a) sobre el sistema operativo Windows 10. Con ayuda del Toolbox GUIDE (graphical user interface development environment) se diseñó la GUI que permitirá utilizar la fórmula propuesta. Finalmente, con MatLab Compiler™ v9.01, se obtuvo una aplicación autónoma. El resultado obtenido con la GUI es 100% la misma que se ha obtenido por otros métodos

A combined analytical method for optimal location and sizing of distributed generation considering voltage stability and power loss in a power distribution system

In this paper, a multi-objective analytical method to evaluate the impacts of optimal location and sizing of distributed generation is presented. This method is based on an analysis of the exact loss formula and continuous power flow in a radial distribution system. Based on two methods of analysis, power loss and weakest voltage buses and lines are calculated and then the optimal size of distributed generation is determined. After that, by considering the minimum power losses and the maximisation of voltage stability, the proposed index determines and ranks positions to decide the optimal distributed generation location in the system. This method allows us to find the best places and size to connect a number of distributed generation units by optimising the objective functions. The simulation results were obtained using a 33-bus radial distribution system to determine the location and size of the distributed generation units. The results show the effectiveness of voltage profile improvement, loading factor improvement and power loss reduction. Further, the problems of a single objective function and the placement of the distributed generation unit using analytical methods are solved by the proposed approach

Planning and impact of distributed generation in SESB existing system

In the recent years the electrical power networks are undergoing rapid restructuring and developing process worldwide. Advancement in technologies and concern about the environmental impacts have led to increase interconnection of renewable energy based distributed generations (DGs) in distribution networks. The DGs have significant impacts on the distribution systems; these impacts may be either positively or negatively depending on the modified interconnected DG distribution network structure. It will be necessary to consider many issues concerning these impacts. In this project, an investigation of DGs impacts on voltage profile and power losses in radial distribution networks is introduced and explained. The method of determining size and placing the DG unit using classical grid algorithm search has been analyses in this report. The performance of the interconnected DG distribution network in terms of power losses and voltage profile also has been analyzed. A comparison between many cases with different numbers, sizes and locations of interconnected DGs are considered and discussed. Detailed simulations using PSS ADEPT are conducted in order to explain and verify the results. At the end of this project, the result showed the significant improvement in terms of power losses and voltage stability

A tool for voltage stability and optimization (VS&OP) in radial distribution systems using matlab graphical user interface (GUI)

WOS: 000256638900003This paper describes a software package whose purpose is to provide a tool to be used for identifying the closeness of the each bus and the critical bus which is the most sensitive to the voltage collapse in radial distribution networks. The package also facilitates two optimization algorithms to be used for the optimal placement of Distributed Generation (DG) and shunt capacitors with their optimal size in distribution networks for power system studies. It uses the graphical user interface (GUI) capabilities of Matlab and is called voltage stability and optimization (VS&OP) Package. It is available at http://www.gyte.edu.tr/Dosya/102/power/ and can freely be downloaded. (C) 2008 Elsevier B.V. All rights reserved

Particle swarm optimisation based DG allocation in primary distribution networks for voltage profile improvement and loss reduction

As there are many potential benefits by integrating the distributed generation (DG) units in a distribution network over conventional system, DG plays a vital role in a power system network. Renewable energy based DG units are located close to the consumers or load centers in order to improve voltage profile, reduce the network power losses and improves substation capacity release etc. Thus, while allocating DG units care has to be taken in order to maximize the benefits. In this thesis, by installing DG, an optimal way of managing real and reactive power and improving the nodal voltages in primary distribution network explained. Optimal location of DG is identified by using voltage stability index (VSI). The optimal rating of DG is computed by using Particle Swarm Optimization (PSO) technique to ensure reduction in power losses and to attain better voltage regulation. To demonstrate the efficiency of proposed techniques a clear and detailed analysis of performance has been carried out on IEEE-33 & 69 bus system

Alocação de bancos de capacitores e reguladores de tensão em redes de distribuição incluindo critérios de máximo carregamento e estabilidade de tensão

Orientadora : Profa. Dra. Thelma Solange Piazza FernandesCoorientador : Prof. Dr. Alexandre Rasi AokiDissertação (mestrado) - Universidade Federal do Paraná, Setor de Tecnologia, Programa de Pós-Graduação em Engenharia Elétrica. Defesa: Curitiba, 26/05/2017Inclui referências : f. 124-130Resumo: Para o problema de alocação simultânea de banco de capacitores (BCs) e reguladores de tensão (RTs) em redes de distribuição, os critérios de otimização tradicionalmente utilizados são os relacionados ao perfil de tensão, perdas elétricas e custo de equipamentos. Este trabalho introduz novos critérios de otimização a este problema, que são o máximo carregamento e a estabilidade de tensão. A solução é obtida via Algoritmos Genéticos (AG) e Fluxo de Potência Ótimo (FPO). Para avaliar a estabilidade de tensão são aplicados dois índices de barra conhecidos na literatura, ambos formulados a partir do determinante da equação de tensão. O cômputo do máximo carregamento é feito via FPO. As simulações realizadas em sistemas teste de 11 e 70 barras revelam que os benefícios da inserção dos BCs e RTs são compartilhados com as novas funções, sem que essa vinculação resulte em custos excessivos de equipamentos. O trabalho constata que a partir do efeito combinado da alocação de BCs e RTs é possível também ajustar bons intervalos de variação para o índice de estabilidade de tensão. Palavras-chave: Estabilidade de Tensão. Máximo Carregamento. Algoritmos Genéticos. Banco de Capacitores. Reguladores de Tensão.Abstract: To the problem that allocates capacitors banks and voltage regulators in distribution networks, the traditional optimization criteria are related to the voltage profile, electric losses and equipment costs. This work introduces new criteria to this problem, which are maximum loadability and voltage stability. The solution is obtained via Genetic Algorithms and Optimal Power Flow. Two bus indices known by the literature are applied to evaluate the voltage stability, both indices formulated from the determinant of the voltage equation. The computation of the maximum load is done via Optimal Power Flow. The simulations, performed using 11 and 70 bus systems, reveal that the benefits of insertion of the capacitors banks and voltage regulators are shared with the new functions, without this linkage resulting in excessive equipment costs. The work shows that from the combined effect of the allocation of capacitors bank and voltage regulators, it is also possible to adjust good intervals for the voltage stability index. Key-words: Voltage Stability. Maximum Loadability. Genetic Algorithms. Capacitors Bank. Voltage Regulators