Electric Power Distribution

Somalia has been experiencing challenges in the distribution of power to the whole country in the past decades. As a result, more than half of Somalia population is affected by the ineffectiveness of the distribution of electricity which lowers their standard of living. A distribution network is one of the main parts of a power system as it is connected directly to the load center and can act as a microgrid during an islanding operation. The concept of integrating both renewable and distributed energy sources at the distribution level is currently of great interest for power system engineers. Further research by power companies and engineers on applying better techniques to improve the power quality and stability of dynamic devices in a distribution network is ongoing. This Research Paper presents a comparative study of radial and ring type electrical power distribution system. Power distribution systems play a significant role, since it is the main link between the power substation and the consumers. Presently power distribution system is done by the radial type system and it has only one path for power flow from distribution substation and to the particular load. The another type of power distribution is ring system and it has one or more paths between the distribution substation and the load. This increases the reliability over the radial distribution system by the quality supply. A five bus distribution system is considered to compare the two different type of systems. The module of distribution system is implemented using the MATLAB/SIMULINK R2014a. The experimental results reveal that the ring type distribution system is more reliable compare to that of the radial distribution system.

This paper discusses the effects of Hurricane Maria on Puerto Rico’s electric grid. Arguably, the most significant effect of Hurricane Maria on Puerto Rico was the electric power outage that initially affected the entire island and lasted more than ten months. Although the damage to the conventional electric power generation infrastructure was relatively minor, both the transmission and distribution portions of the grid suffered much worse damage than that observed during other hurricanes that affected the U.S. in the past decade. This extensive damage added to logistical limitations and the island orography were important factors that contributed to an extremely slow restoration process leading to a very low resilience for the island’s power grid. This paper describes all these aspects in detail and supports the explanation of the hurricane effects with photographic evidence collected during a damage assessment conducted in the early December 2017 when about half of the electricity...

This paper provides a review of the research conducted on complex network analysis (CNA) in electric power systems. Moreover, a new approach is presented to find optimal locations for microgrids (MGs) in electric distribution systems (EDS) utilizing complex network analysis. The optimal placement in this paper points to the location that will result in enhanced grid resilience, reduced power losses and line loading, better voltage stability, and a supply to critical loads during a blackout. The criteria used to point out the optimal placement of the MGs were predicated on the centrality analysis selected from the complex network theory, the center of mass (COM) concept from physics, and the recently developed controlled delivery grid (CDG) model. An IEEE 30 bus network was utilized as a case study. Results using MATLAB (MathWorks, Inc., Nattick, MA, USA) and PowerWorld (PowerWorld Corporation, Champaign, IL, USA) demonstrate the usefulness of the proposed approach for MGs placement.

... most commonly unidirec-tional two-stage converter featuring the step-up (boost) dc-dc converter stage and ... and 400 V to allow for power sharing and voltage regulation using the droop control. ... Starting with the bidirectional grid interface converter, its VI curve is shown at the top ...

Abstract: One of the contentious issues in electricity reform is whether there are significant gains from restructuring systems that are moderately well run. South Africa's electricity system is a case in point. The sector's state-owned utility, Eskom, has been generating some of the lowest-priced electricity in the world, has largely achieved revenue adequacy, and has financed the bulk of the government's ambitious electrification program. Moreover, the key technical performance indicators of Eskom's generation plants have reached world-class ...

The objective of the tutorial is to present the results from the CIGRE/CIRED C6.25/B5 Joint Working Group (JWG) that has worked on the control and automation systems for the future electric networks with particular reference to the TSO/DSO interface. The main focus is on the evaluation of the level of automation and control necessary to better manage distribution networks with large penetrations of Distributed Energy Resources (DERs), as seen from both the TSO and DSO perspectives, and to provide services and information about the two level of management (i.e., at TSO and DSO level).

U radu je obrađena problematika procjene gubitaka elektricne energije proracunom i mjerenjima. U prvom dijelu predstavljen je nacin bilanciranja elektricne energije u distribuciji i kriticki osvrt na postojeci nacin ocitavanja potrosnje na brojilima potrosaca te prijedlog poboljsanja. Drugi dio rada posvecen je metodama procjene gubitaka u distribucijskoj mreži uz pomoc programske podrske te vrste podataka koji su za tu svrhu potrebni. Treci dio rada bavi se problemom znacenja cijene gubitaka, metodama njihova izracuna i primjerima primjene. Valja istaknuti cetvrti dio rada u kojem je primijenjen model proracuna tokova snaga na temelju mjerenja dijagrama opterecenja u SN mreži, a rezultati proracuna koristeni za zahvate, kojima su gubici u mreži smanjeni. Prikazan je i konkretan nacin smanjenja komercijalnih gubitaka, te prijedlozi kako ih pronaci i ukloniti.

With the increasing integration of renewable energy sources into the electricity supply system, planning and operation of power distribution systems has become more complex and challenging. As a consequence of this progress, new and innovative concepts for distribution system operation are in research. Therefore, detailed grid models are required. Due to different power demand and generation according to the region, these grids show a very heterogenous structure. Thus, this paper proposes an approach to synthesize grid models based on the real supply task of German grids.Publicly available data of geoinformation systems, demography, and power generations in combination with a probabilistic approach based on evaluations of real grid data is used to identify the electricity supply task in high spatial resolution. Considering the local supply task, the grid topology is simulated in a two-step heuristic, including a capacitated vehicle routing problem to determine the basic grid topolog...

This paper discusses the effects of Hurricane Maria on Puerto Rico’s electric grid. Arguably, the most significant effect of Hurricane Maria on Puerto Rico was the electric power outage that initially affected the entire island and lasted more than 10 months. Although damage to the conventional electric power generation infrastructure was relatively minor, both the transmission and distribution portions of the grid suffered much worse damage than that observed during other hurricanes that affected the U.S. in the past decade. This extensive damage added to logistical limitations and the island orography were important factors that contributed to an extremely slow restoration process leading to a very low resilience for the island’s power grid. This paper describes all these aspects in detail and supports the explanation of the hurricane effects with photographic evidence collected during a damage assessment conducted in early December 2017 when about half of the electricity customer...

... To achieve a fast dynamic response, the boost converter is primarily controlled by an inner current ... To investigate the performance of the DC-linked microgrid, simulation studies were conducted for a ... [31] A. Al-Hinai, K. Sedhisigarchi, and A. Feliachi, “Stability enhancement of a ...

ÖZETÇE: Bu makalede “Çok-yollu Hoparlör Sistemlerinde Güç Dağılımı” konusu ele alınmakta ve Çok-yollu Hoparlör Sistremlerinde Güç Dağılımına ilişkin bir abak sunulmakta ve bu abağın nasıl kullanılacağı örneklerle açıklanmaktadır.
Piyasada bulunan çeşitli “hoparlör transformatörlerinin”, hoparlörlere bağlantıları gösterilmektedir. “LC-elemanlarından oluşmuş Yüksek Fideliteli İki-yollu Bölüştürücü Süzgeç Devresi” ele alınmakta ve bunun devre şemasından montaj şemasına geçiş kısaca açıklanmaktadır.
Çok-yollu hoparlör sistemlerinde kullanılacak olan hoparlörlerin genlik-frekans karekteristikleri yekdiğeriyle kesişmelidir. Karekteristiklerinin kesişme noktası, bir hoparlörden ötekine geçiş sağladığı için “geçişleme” veya “ kesişme” noktası diye adlandırılmaktadır. Öteyandan, karekteristiklerin kesişme noktasındaki frekansa “bölüştürme frekansı” ( cross-over frequency) denmektedir.
Ses frekans görüngesi (spektrumu) boyunca, herbir hoparlörün istenen seviyede akustik enerjiyi yayabilmesi gerekir. Hoparlör seçilirken hem “Duyarlıkları” ( Sensitivity), hem de “Direme Güçleri” (Power Handling Capacity) gözönüne alınacaktır.
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The last decades the concern of the public, regarding the possible affects from the exposure to magnetic and electric fields, has grown considerably. This is because the generation, transmission and distribution of electric power are accompanied with the presence of the above mentioned fields. This paper attempts to illustrate the values of the resultant magnetic field in the low frequency

Reconfiguration of a power distribution system consists in changing the functional links among its elements and represents one of the most important actions for the improvement of system performance in operation. In the last few years, some authors have proposed approaches based on Pareto optimality for problem formulation of reconfiguration, with active power losses and reliability indices as objectives. The study highlights the optimization importance of reliability indices which refer to the interruption frequency, especially because, in the context of smart grids, the fastness of the reconfiguration method contributes, by itself, to reduce the duration of interruptions. There is no unique recognition concerning which approach is the most suitable to be used in order to solve the reconfiguration as a Pareto-optimal problem. The most important aspect is the way in which the specific information of the problem field is modelled in the implementation. Also, the dimension of a Pareto-front can vary widely from a test system to another.