Configuration Of Distribution System Research Articles

Quantitative assessment of charging ports in EV charging stations from reliability and economic perspective in the distribution system

With the emerging development of electrical vehicles (EVs) in transportation, the utilization manufacturing companies are concentrating on the development of charging facilities for customers. Maintaining the reliability of charging ports is a difficult task for the intermediate charging conditions of EVs, even though the charging station industries are installing the charging stations as per the specifications of the distribution system. To improve the reliability of the charging station for the distribution system, the 12 and 24-ported configurations have been proposed and systems have been designed with the individual batch structure. The performance analysis of the proposed non-uniform configurations has been estimated in terms of reliability as per the failure rate of the individual port in batch. The proposed 12 and 24-ported configuration’s failure rate has been evaluated with the standards of MILHBK-217 F. According to the failure rate of the port, the evaluation process has been introduced to find the success rate of the charging station. The maintenance cost has been estimated based on the failure and success rate of the proposed 12 and 24 systems. Finally, the performance analysis of the proposed 12 and 24-port configurations comparison has been estimated in terms of failure rate, success rate and maintenance cost. In this work, the binomial distribution probability technique has been implemented for the appropriate failure rate estimation of the charging station. The proposed 12 and 24-port non-uniform configurations are capable of providing reliable operation and are implementable for the low area of the plinth for EV charging stations.

A two-stage risk-based framework for dynamic configuration of a renewable-based distribution system considering demand response programs and hydrogen storage systems

Distribution feeder reconfiguration (DFR) in distribution systems can enhance operating conditions by reducing losses and improving voltage indices. This paper introduces a dual-stage risk-based framework that concurrently tackles day-ahead reconfiguration and microgrid scheduling within the distribution network. To control the negative aspects of uncertainties, the proposed framework integrates energy storage systems (ESS/HSS) and demand response programs (DRPs) at the network level, enhancing adaptability. The initial stage of the proposed model employs the AC power flow model, utilizing loss and voltage deviation functions as objective benchmarks for network reconfiguration. The scheduling is meticulously executed per interval, deriving optimized structures under diverse scenarios with the aid of a case reduction technique (CRT) to streamline solutions. The ultimate solution employs the grey wolf optimization (GWO) algorithm and CPLEX solver in the first and second stages respectively. Outcomes from applying this approach to the adjusted 118-bus network manifest improved operational conditions and voltage quality through reconfiguration. Impressively, the integration of ESS/HSS and DRPs yields a substantial 22.34% reduction in total operating costs, a conclusion substantiated by the numerical findings. Furthermore, by leveraging the CRT, a remarkable 56.17% reduction in problem-solution time is achieved.

Reliability Evaluation of a Radial Feeder Configurations by Replacing the Distribution Transformer with the Solid-State Transformer

The radial feeder is the most typical power distribution system configuration for distributing power to the consumer through the distribution transformer. Distribution transformers are a key component of power distribution systems, they enable voltage transformation, improve safety, reduce energy losses, enhance network reliability, and facilitate the efficient distribution of electricity to consumers. Due to the lack of their role in balancing loads and integrating renewable energy sources, they must be replaced with an alternate solution for modernizing and optimizing distribution grids. A solid-state transformer (SST) is a power electronic device that, in many ways, may replace a typical distribution transformer (DTR). It also improves controllability and provides a direct current link, making it simple to integrate distributed energy sources on either sides of medium and low voltage. However, reliability is the most important parameter in restricting its applications. Modularity is one of the ways to improve reliability and availability by directly re-routing the power within the modular system. This work investigates the failure rate of a modular SST by determining the number of module units required in SST design based on the available IGBT ratings. Further, the reliability of a radial feeder is evaluated by considering the configuration of a) without AS and with DTRs, b) Without AS and replacement of DTRs with SST, c) With AS and DTRs, and d) With AS and replacement of DTRs with SST.

Online evaluation of the distribution system resiliency criteria using Choquet‐based graph technique

AbstractNowadays, due to network expansions, system operators are dealing with natural events including system failures. Evaluating the system readiness to maintain the network interconnections during severe faults are known as an important challenge of today's distribution networks. To do this, this paper presents an online non‐model‐based scheme of evaluating the system resiliency and supplying critical loads within severe natural conditions. In this case, by developing system resiliency as multi‐metric decision making problem and proposing the Choquet integral and graph theoretic methodology, the system resiliency is evaluated. The proposed resiliency scheme is an online non‐model‐based approach can be used for all distribution system configurations with the potential of natural event failures. In this case, by proposing online resiliency criteria based on the system critical loads and branches and developing the proposed criteria on Choquet integral scheme in the form of optimization procedure, the system resiliency is evaluated. The validity of the proposed approach is carried out on two different systems including the IEEE 123‐bus test system and the Consortium for Electric Reliability Technology Solutions (CERTS) microgrid. Simulation results present effectiveness of the proposed scheme to provide proper protective switching strategy and design the system resiliency criteria for future distribution systems.

Techno-Economical Effects of Adopting Small Capacity Transformers on Ado-Ekiti 11/0.415 kV Power Distribution Networks

The major portion power loss in power system occurs in the components of low voltage (LV) networks. Low voltage distribution system (LVDS) configuration has been observed to contribute significantly to power loss and unacceptable voltage drop in the system due to its structure and higher current flow in the network. The adoption of small capacity transformers as high voltage distribution system (HVDS) configuration is increasingly applied to the network for power loss reduction and the improvement of voltage profile. This study aims to evaluate the technical and economic implication of the use of HVDS configuration on Ado-Ekiti 11/0.415 kV power distribution networks and provide necessary recommendations. The network data was obtained and modeled on NEPLAN software for simulation and technical evaluation of the networks. The existing LV lines were upgraded to high voltage (HV) and remodeled with small capacity transformers and comparative analysis of the technical and economic effects of the networks were carried out. The results obtained showed that there could be feeder capacity increase of 92.03 kW and power loss reduction of 347.17 kW and 459.72 kVar following reconfiguration from LVDS to HVDS. The losses in the transformers and lines were significantly reduced by 37.8% for HVDS configuration when compared with the LVDS configuration. The voltage profile was significantly improved with voltage deviations in the range of ± 0.01 to ± 0.03 of bus voltage for the HVDS network when compared to the existing network. The cost of implementation of the HVDS network substation was calculated to be ₦807,238,715.50 and with the combination of annual savings and an increment in tariff of ₦5/kWh in the billing charge of unit energy consumption resulted in a payback period of 2 to 3 years for the estimated capital investment. This study showed that technical performance of HVDS implementation on the Ado-Ekiti network feeder was better than that of the existing network.

Airborne migration behaviour of SARS-CoV-2 coupled with varied air distribution systems in a ventilated space

Air distribution system could critically affect SARS-CoV-2 transmission in indoor space; therefore, this study aims at demonstrating numerical characteristics of SARS-CoV-2 migration with varied air distribution system configurations. Seven cases were investigated regarding three major aspects: how fast suspended particles can be removed from the ventilated space or changed into deposited particles; how much particles are attached to various object surfaces which leads to an infection by touching fomite. All cases were analyzed through computational fluid dynamics (CFD). Both different shapes (round or linear diffusers) and installation locations (ceiling or floor) of inlet and outlet diffusers were investigated. Results showed that different air distribution system would lead to different dispersion profiles of infectious particles and different deposition pattern of particles on interior surfaces. With the same air flow rate, linear-diffuser would perform better for CO2 extraction while requiring less time to remove or collide the same magnitude of suspended droplets compared to round-diffuser. However, how quickly removed or suspended droplets collide is not proportional to how less the number of total particles are remained. Two additional cases with double sized space possessing best ventilation configuration were also examined to explore potential application of the best-ventilated configuration to various spatial expansion cases.

Robust Mixed-Integer Programing Model for Reconfiguration of Distribution Feeders Under Uncertain and Variable Loads Considering Capacitor Banks, Voltage Regulators, and Protective Relays

Feeder reconfiguration is an effective way to reduce power losses of distribution network. In this way, configuration of distribution system is changed in order to achieve possible minimum losses, while electricity demand of consumers has to be provided. Consumers’ power demand has an important role in feeder reconfiguration because any change in demand affects power losses directly. Whereas load demand has a variable and stochastic nature because of its dependence on consumption pattern and accuracy of forecasted load amounts. Accordingly, reconfiguration models should be robust enough against load uncertainty and variations. Thus, this article presents an efficient robust model for reconfiguration of distribution feeders under uncertain and variable loads. The proposed reconfiguration model is robust enough and efficient, in which its implementation is relatively simple. The results show higher efficiency and lower complexity of the proposed model compared to existing robust reconfiguration approaches.

An approach to the utilization of grid integration to analyze the performance and quality of solar photovoltaic model

Photovoltaic power is most important cause of energy subsequently it is simultaneously clean and limitless. PV power conversion devices must be maintained at MPP there to maximize the energy production of Solar array. To get the most energy out of the Solar array, MPPT monitoring is necessary. In recent times, a slew of strategies for controlling the voltage was presented. Power electronic devices developments for the combination of wind and solar power generation are discussed. Based on the dependability and development of each technology, conversations concerning developments and trends in sustainable source systems are provided. The consumption of electricity generated is increasing exponentially, and as a result, the incorporation of photovoltaic panels into distribution companies is increasing rapidly as well, even though it has a substantial impact on the show’s voltage stability. The purpose of this report is to look at how solar PV integration affects distribution transmission energy reliability. The analysis is carried out using RSCAD software, with one of the radial distribution networks with the lowest voltage profile accessible during the maximum of linked loads. Furthermore, the influence of current and voltage on the transmission or distribution system is compared by analyzing distribution system configuration with various solar PV system penetration rates. The simulated findings show that as the penetrating capability of the PV system increases, large harmonic distortion levels are injected, indicating that the solar photo system should only integrate corresponding to the highest capability the connection can sustain. When a PV technology is connected further than this maximum penetration of renewable energy sources, it produces considerable harmonic components, which harms the system that improves. Total voltage output frequency and current consumption distortion are determined to be 4.98 percent and 14.99 percent, correspondingly, at the maximum diffusion way that enables the permissible harmonic distortion limitation. Thus, the research presents the uses of Grid Integration to estimate the performance and the quality of the solar PV model.

An Analog-Device-Based Five-Domain Control Method and Distributed System Configuration for High-Power Spacecraft Power Systems

Deep space exploration is gaining increasing interest as the space station and lunar base projects are putting on the agenda. Due to the limited power level of the power controlling unit (PCU), high-power space power systems have to be constructed with several PCUs, forming a PCU interconnection system. However, the existing control methods and architectures are either unsuitable for systems with more than two PCUs or must be implemented with the digital controller, which is rarely used in space power systems due to the single-event upset (SEU). In this article, a communication-free distributed configuration for PCU interconnection system and a novel analog-device-based five-domain control method are proposed. Detailed control strategies and five working modes of the PCU subsystem are analyzed. Seamless switch during mode transition is realized by designing control parameters carefully, which ensures the stability of the PCU bus voltage. A three-PCU interconnection system is constructed, and both steady-state and dynamic responses of the system are tested, validating the effectiveness of the proposed control method.

Design and implementation of dynamic I/O control scheme for large scale distributed file systems

In this work, we have analyzed the input/output (I/O) activities of Cori, which is a high-performance computing system at the National Energy Research Scientific Computing Center at Lawrence Berkeley National Laboratory. Our analysis results indicate that most users do not adjust storage configurations but rather use the default settings. In addition, owing to the interference from many applications running simultaneously, the performance varies based on the system status. To configure file systems autonomously in complex environments, we developed DCA-IO, a dynamic distributed file system configuration adjustment algorithm that utilizes the system log information to adjust storage configurations automatically. Our scheme aims to improve the application performance and avoid interference from other applications without user intervention. Moreover, DCA-IO uses the existing system logs and does not require code modifications, an additional library, or user intervention. To demonstrate the effectiveness of DCA-IO, we performed experiments using I/O kernels of real applications in both an isolated small-sized Lustre environment and Cori. Our experimental results shows that our scheme can improve the performance of HPC applications by up to 263% with the default Lustre configuration.

Optimal Pole-Swapping in Bipolar DC Networks Using Discrete Metaheuristic Optimizers

Bipolar direct current (DC) networks are emerging electrical systems used to improve the distribution capabilities of monopolar DC networks. These grids work with positive, negative, and neutral poles, and they can transport two times the power when compared to monopolar DC grids. The distinctive features of bipolar DC grids include the ability to deal with bipolar loads (loads connected between the positive and negative poles) and with unbalanced load conditions, given that the loads connected to the positive and neutral poles are not necessarily equal to the negative and neutral ones. This load imbalance deteriorates voltages when compared to positive and negative poles, and it causes additional power losses in comparison with balanced operation scenarios. This research addresses the problem of pole-swapping in bipolar DC networks using combinatorial optimization methods in order to reduce the total grid power losses and improve the voltage profiles. Bipolar DC networks with a non-solidly grounded neutral wire composed of 21 and 85 nodes are considered in the numerical validations. The implemented combinatorial methods are the Chu and Beasley genetic algorithm, the sine-cosine algorithm, and the black-hole optimization algorithm. Numerical results in both test feeders demonstrate the positive effect of optimal pole-swapping in the total final power losses and the grid voltage profiles. All simulations were run in the MATLAB programming environment using the triangular-based power flow method, which is intended for radial distribution system configurations.

Dynamic Multi-projection Mapping Based on Parallel Intensity Control.

Projection mapping using multiple projectors is promising for spatial augmented reality; however, it is difficult to apply it to dynamic scenes. This is because the conventional method decides all pixel intensities of multiple images simultaneously based on the global optimization method, and it is hard to reduce the latency from motion to projection. To mitigate this, we propose a novel method of controlling the intensity based on a pixel-parallel calculation for each projector in real-time with low latency. This parallel calculation leverages the insight that the projected pixels from different projectors in overlapping areas can be approximated independently if the pixel is sufficiently small relative to the surface structure. Additionally, our pixel-parallel calculation method allows a distributed system configuration, such that the number of projectors can be increased to form a network for high scalability. We demonstrate a seamless mapping into dynamic scenes at 360 fps with a 9.5-ms latency using ten cameras and four projectors.

Impacts of Introducing PV Power System into Different Distribution System Configurations on their Reliability. (Dept. E)

Impacts of Introducing PV Power System into Different Distribution System Configurations on their Reliability. (Dept. E)

Optimisation of the Two-Tier Distribution System in Omni-Channel Environment

This paper deals with the problem of the design and configuration of a distribution system that supports the delivery of goods to customers using various commercial channels. In this sense, a modelled distribution system, called an omni-channel distribution system, should ensure the delivery of the same products in different ways while guaranteeing its highest efficiency. The authors propose a single-criterion mixed-integer programming model for the configuration of a complex distribution system of goods in an omni-channel environment. A minimized cost function, composed of key logistics elements including transport, warehouse location, and manipulation processes, is the objective function. The model was experimentally verified, and as a result, potential savings of around 5–8% of the omni-channel design distribution system costs versus the multi-channel distribution system costs were identified. In the paper, an extended sensitivity analysis is also performed to show how specific parameters of the model can change the final recommendation.

Location of Urban Logistics Spaces (ULS) for Two-Echelon Distribution Systems

The main concern in city logistics is the need to optimize the movement of goods in urban contexts, and to minimize the multiple costs inherent in logistics operations. Inspired by an application in a medium-sized city in Latin America, this paper develops a bi-objective mixed linear integer programming (MILP) model to locate different types of urban logistics spaces (ULS) for the configuration of a two-echelon urban distribution system. The objective functions seek to minimize the costs associated with distance traveled and relocation, in addition to the costs of violation of time windows. This model considers heterogeneous transport, speed assignment, and time windows. For experimental evaluation, two operational scenarios are considered, and Pareto frontiers are obtained to identify the efficient non-dominated solutions to select the most feasible ones from such a set. A case study of a distribution company of goods for supermarkets in the city of Barranquilla, Colombia, is also used to validate the proposed model. These solutions allow decision-makers to define the configuration of ULS networks for urban product delivery.

Decentralized transactive energy management of multi-microgrid distribution systems based on ADMM

Presence of microgrids (MGs) and renewable energy sources (RESs) in distribution power systems could result in dramatic changes in operation and planning of these systems. In this regard, operational procedures employed by utilities should take into account the intermittent nature of RESs, while coping with the independent operation of MGs. In this perspective, this paper develops a distributed power management framework based on alternating direction method of multipliers (ADMM) for distribution networks with multi-MG (MMG) structures. The proposed approach develops a transactive signal in the context of ADMM to coordinate operation of MGs in a distributed manner. In this context, the configuration of MMG distribution systems is devised in a way that facilitates modern distributed control of the system by eliminating the role of a central coordinator in traditional distribution systems. Moreover, robust optimization technique is deployed in the MG operational scheduling to handle the uncertainty associated with RESs. Finally, through a numerical case study, the efficiency of the proposed framework to schedule local resources for MMG distribution systems is analyzed.

Analysis of interconnected configuration for penetration of distributed generation

This paper visualizes the feasibility of the proposed interconnected distributed power system configuration, which aims at incorporating the electricity generation from renewables and to cater to low voltage areas of radial distribution network. The shortcoming of existing traditional radial systems is inconsistent load distribution and technical viability in incorporating renewable sources without disturbing the power system. Sustainable development is achieved with improvement in the prevailing distribution system. Maximum potential benefits in terms of demand-supply balance and integrating renewables can be achieved by selecting properly placed and optimally sized distributed generation sources in a distribution network. The generation facility is selected as per the geographical profile of the location and placed on the weakest node. The weakest node is the low voltage profile region where the maximum output of the integration of power sources is beneficial. In this paper, the ZIP model-based methodology is applied to feeder loads on the data set of the distribution grid of the National University of Science & Technology (NUST), Islamabad, Pakistan. The comparative analysis is performed on a radial network of NUST distribution grid and compared with a simulated interconnected distribution system of the same distribution network on MATLAB software as a case study to observe the performance of interconnected power systems. This analysis results in better voltage profiles for interconnected networks, compared to radial networks. That said, incorporating a Distributed Generation (DG) source in the interconnected network builds a substantial impact on the distribution system voltage profile. The efficacy of the proposed interconnected system confirms the performance improvement of the distribution power system. The VSI values for interconnected systems give better results which is further justified by the machine learning algorithm, Logistic regression. The simulation results indicate that the Interconnected system encourages penetrations of solar, wind, gas turbine, and other renewable sources near the low voltage end in the distribution system. © 2021 Bilal Asghar Farooqi et al.

Simulation analysis of current protection in distributed power distribution network

The massive access of distributed power sources makes the distribution network into an active network with bidirectional power flow, which increases the economics and flexibility of grid operation. However, the protection configuration of traditional distribution systems is based on a single power system. And distributed power has a certain randomness, and its fault current characteristics will change, which complicates the protection of distribution network with distributed power. In order to solve this problem, this paper first builds a distribution network with multiple distributed power sources based on the RTDS simulation platform, and simulates the fault current characteristics of the line faults. Then it sets up a three-stage current protection and supplies power based on the two-sided power supply The network calculates its setting value; finally analyzes the problems existing in the three-stage protection under the network and proposes the idea of using wide area protection as a backup protection.

ПОВЫШЕНИЕ ЭНЕРГОЭФФЕКТИВНОСТИ ПРОИЗВОДСТВА ЗА СЧЕТ ПРИМЕНЕНИЯ СИЛОВЫХ ФИЛЬТРОВ ВЫСШИХ ГАРМОНИК

Актуальность. В настоящее время все большее количество технологических процессов и производств в нефтегазовой отрасли реализуется на базе высокопроизводительного оборудования с полупроводниковыми преобразователями электрической энергии, в число которых, например, входят частотно-регулируемые электроприводы переменного тока или бесперебойные источники питания, которые относятся к классу нелинейных нагрузок и могут вызывать большое количество негативных явлений в работе распределительных сетей, включающих в себя несимметрию фазных напряжений и токов, резонансные процессы, тепловые потери в нейтральном проводе, перегрев двигателей и трансформаторов и т. д. Для улучшения электромагнитной совместимости различного рода электроприемников в составе промышленных систем электроснабжения довольно часто используют пассивные конденсаторные батареи для коррекции коэффициента мощности, которые малоэффективны в случае нелинейных процессов. Кроме этого, данный тип компенсационных устройств продолжает потреблять реактивную энергию при отсутствии каких-либо нагрузок и не удовлетворяет современным требованиям в области энергосбережения. Описанные выше недостатки в работе трехфазных систем переменного тока требуют разработки новых схемотехнических решений, методов анализа энергетических процессов и синтеза алгоритмов силовой фильтрации, позволяющих обеспечить нормированные показатели качества электрической энергии в распределительных сетях низкого и среднего классов напряжения вне зависимости от конкретного вида электрических цепей нагрузки. Цель исследования заключается в комплексном анализе существующих технических решений, направленных на повышение электромагнитной совместимости распределительных сетей, а также в описании основных ограничений в работе силовых фильтрокомпенсирующих устройств применительно к промышленным объектам минерально-сырьевого комплекса; в разработке базовых структур активных силовых фильтров с пониженными требованиями по производительности, объему памяти и быстродействию программно-аппаратной части системы управления, практическое применение которых обеспечивает нормированное качество электрической энергии при изменении режимов работы технологического оборудования или конфигурации питающей линии. Объекты: автономные или децентрализованные электроэнергетические системы переменного тока с преобразовательными устройствами силовой электроники и частотно-регулируемыми электроприводами, а также элементами силовой цепи с нелинейными характеристиками, например, реакторами или трансформаторами с насыщенными сердечниками, в которых присутствуют значительные искажения в мгновенной форме трехфазных сигналов; пассивные и активные силовые фильтры высших гармоник. Методы: некоммутативная алгебра кватернионов; четырехмерное гиперкомплексное пространство; методы спектрального анализа и разложения в ряд Фурье. Результат: краткий обзор различных подходов и технических средств к повышению качества электрической энергии в системах электроснабжения промышленных объектов минерально-сырьевого сектора, а также системы управления,рамках которых достигается синусоидальный закон изменения во времени сетевых токов с нулевым или опережающим/отстающим угловым сдвигом при одновременном соблюдении условия симметрии по мгновенным значениям.

Autonomous Self-Healing in Smart Distribution Grids Using agent Systems

When a fault occurs on a distribution system, it should be isolated. After isolation, the distribution system can be reconfigured to restore the out-of-service area. The distribution system configuration can be changed by performing switching actions on the feeders. This paper proposes an agent-based approach for service restoration in smart distribution systems. The proposed multiagent approach has three different types of agents, namely, feeder agents, zone agents, and switch agents. The agents can communicate and cooperate with each other in order to supply services to out-of-service customers. The restoration plan is built on the basis of local data considering system conditions, operational constraints, and the fault location. Different loading conditions have been considered under different scenarios, and the results of the proposed multiagent approach for each scenario have been compared. Simulation results show the efficiency of the proposed agent architecture.