6-phase System Research Articles

La vulnerabilidad del embarazo en las trabajadoras del sexo

Objective: To evaluate the exposure of the mother-baby binomial to complications in sex workers. Methods: This is an integrative literature review that followed a 6-phase system. The research took place in the Virtual Health Library in the following databases: Nursing Database (BDENF- Nursing), Online Medical Literature Analysis and Recovery System (Medline), Latin American Literature of Health Sciences (LiLACS), Spanish Bibliographic Index of Health Sciences (IBECS-ES), National Center for Biotechnological Information (NCBI), SAGE Journals with the descriptors: sex workers and sexually transmitted infections, prostitution and sexually transmitted infections, prostitution and vulnerability, from March to April 2019; 105 articles were identified and were submitted to the exclusion and inclusion criteria, and 25 publications were obtained for the sample. Results: Based on the analysis of the articles the following categories were determined: sexually transmitted infections (STIs), violence and illicit or licit drugs are linked. Conclusion: Despite the limitation of sampling, the study allowed us to evaluate that the mother-baby binomial is vulnerable to several complications such as spontaneous abortion, growth restriction, premature labor, fetal and/or maternal death, prematurity, physical and behavioral abnormalities of mother and baby, and placental detachment, due to suffered violence, acquired sexually transmitted infections and used substances. Keywords: Sex workers, Pregnancy, Vulnerability.

Pengembangan Peralatan Simulasi Peralatan Aliran Daya Berbasis Fast Decoupled-Dependent Newton-Raphson dengan Program Interface-Based Delphi

On one hand, the particular objective of this research is to yield the software program in order to control efficiently the important aspects in electric power systems which can be implemented in industries. In the other hand, the longterm objective is to extend the curriculum, syllabi, laboratory facilities, and to improve the abilities and qualities of graduates continuously either within State Polytechnic of Ujung Pandang or outside. Method used to achieve these objectives is making, design and implementation which will be last for two years. Simulator for generation system in the first stage of the research is balanced six-phase system yielded from the circuit of 3-one phase centre-tap transformers of 220/18 V, 15 A, as the supply of low-tension 3-phase system, which feeds six one-phase transformer of 18/220 V, 20 A, whose output as another balanced 3-phase system with 220 V/phase. From balanced 6-phase system, a balanced 3-phase will simulate generator number 1 and another balanced 3-phase will simulate that of number 2. Interface which is based on Delphi program is to switch all transmission lines. The result of experiment shows that voltages in the two generator busbars experience the significant drop voltage if they work separately, that are 20.5% - 36.4% and 20.5% - 63.6% for generator number 1 and number 2 respectively, for one to three load busbars operated sequentially, which also reveals that greatest voltage drop occurs in the generator busbar with most lines supplied. Simulating the two generators working simultaneously, then voltage drops are more significant, that are 65.9% - 72.7% and 65.9% - 79.5% for generator number 1 and number 2 respectively, for one to three load busbars operated sequentially, which also proves that transformer bank as generator simulator needs to increase its current capacity.

Two Three-Phase Symmetrical Component Filters of 6-Phase Electrical Power Systems

In the technology of high phase order electric power transmission, 6-phase systems appear to be the most promising among the multi-phase transmission systems. Different techniques of symmetrical components have been proposed for analyzing the 6-phase power system under unbalanced condition. The motivation of writing this article arises from the question: How could the different symmetrical components of the 6-phase systems be measured? This article starts with a review of the “two three-phase symmetrical components theory” that has been proposed for analyzing 6-phase systems. Then, filters for measuring the symmetrical components of voltages and currents using this theory are presented.

A study of EMF mitigation underneath power lines and lightning-shielding enhancement by extra ground wires

This paper presents a theoretical study of the influence of extra ground wires (EGW) on both the electromagnetic fields (EMF) mitigation underneath 765 kV, 3-phase, double circuit transmission lines and the lightning-shielding performance. The method of moments (MOM) combined with the transmission-line model is used to simulate both the aforementioned transmission lines comprising the towers and the lightning channel in three dimensions, where the influence of the channel radiated EMF is taken into account. For power frequency AC energization, the EMF at 1 m above the ground level and at the surface of the phase conductors, and the induced currents in both normally used top ground wires and EGW are computed for various phase arrangements and numbers of EGW. In addition, the lightning-shielding performance with and withont the EGW is introduced and discussed without AC energization. The induced voltages and currents in the phase conductors and ground wires as well as the voltage across the insulators are computed, with and without the EGW, due to different lightning-current amplitudes and waveforms, and return-stroke velocities. The most advantageous merits of using the EGW are as follows. (1) The EMF underneath the overhead power lines are drastically reduced with a negligible effect on the conductors' surface gradient and the charging currents. This can be generally used to meet regularity limits, especially when converting the existing 3-phase double circuit transmission lines to 6-phase systems so that the power handling capability can be increased by up to 73% via increasing the operating voltage. (2) The lightning-shielding performance is significantly improved by reducing the lightning-induced voltages and currents in the phase conductors as well as the voltage across the insulators, i.e. decreasing the probabilities of flashover and back-flashover and enhancing the reliability.

Magnetic field of high-phase order and compact transmission lines

Research has been conducted in high phase order (HPO) power transmission wherein 6 or 12 phases are used to transmit power in less physical space and with reduced environmental effects than conventional designs. In this paper, existing 3-phase double circuit transmission lines (TL) are reconfigured to 6-phase systems for the purpose of calculating and comparing the magnetic field of both systems. The magnetic field of several single-phase configurations; flat, vertical, delta and inverted-delta with the same degree of compaction is calculated and analysed at 1m height above the ground level. The magnetic field of the inverted-delta arrangement, which showed the lowest field profile, is compared with the magnetic field of 6- and 12-phase TLs having the same degree of line compaction and current loading conditions. The three systems are analysed when their lowest conductors had the same clearance to ground in one case and when their highest conductor positions were matched in another case. A comparison between 12-, 6- and 3-phase double circuit TLs having the same degree of compaction, the same phase voltage, the same clearance to ground and the same current per conductor is made to demonstrate if HPO lines reduce fields or not. The 6- and 12-phase lines are raised while keeping their conductors within the space, which would be taken by the conductors of the double circuit line. In this case, the highest conductor positions of the two systems are matched and the magnetic field is recomputed to conclude the results. The vector magnetic field potential concept, as extended to HPO transmission lines, together with a flexible developed computer program are used to calculate and present the magnetic flux density components profiles around the mentioned systems. Copyright © 2002 John Wiley & Sons, Ltd.

Estimation of errors in the fault analysis of six phase transmission lines using transposed models

Fault analysis of power systems represented by transposed line models result in errors that are less tolerable in high phase order systems than in 3-phase systems. Concepts of vector and matrix norm theory are applied to estimate such errors in 6-phase systems without actually making exhaustive fault studies. Error estimates are compared to actual values in typical 3-phase and 6-phase systems.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Steady-state modelling of six-phase (multiphase) transmission systems

The modelling aspects of a 6-phase (multiphase) power transmission system, which have not previously been fully explored in the literature, are discussed. Initially, representations of various components, namely 3-phase/6-phase transformers, 6-phase transmission lines, machines and loads, are developed. A multiphase (or composire 3-phase and 6-phase) power system is then modelled: in balanced conditions on a single-phase basis, in unbalanced conditions as an equivalent 3-phase system; and also as a composite 3-phase and 6-phase system retaining the physical identities of the different elements. The procedure is explained with the help of a numerical example.

Analysis of Multiphase Power System Networks

Multiphase power systems appear to have bright future prospects over conventional 3-phase systems. The 4-phase and 6-phase systems specifically, are the most promising in terms of economy and flexibility. These multiphase power systems are inherently symmetric and exploiting these symmetries, the linear power invariant transformation with complex elements similar to the symmetrical components and with real elements similar to the Clarke's components which are used to diagonalize the coefficient matrix of the power system networks, are derived using group theoretic techniques. Corresponding sequence impedances and complex power are also presented. These results will be very useful for planning the operation of the large scale power system ana also its fault analysis for the purposes of designing adequate protective schemes.