Power system operation and planning

In emerging electric power systems, increased transactions often lead to the situations where the system no longer remains in secure operating region. The flexible Ac transmission system (FACTS) controllers can play an important role in the power system security enhancement. However, due to high capital investment, it is necessary to locate these controllers optimally in the power system. FACTS devices such as UPFC can regulate the active and reactive power control as well as being adaptive to voltage-magnitude control simultaneously because of their flexibility and fast control characteristics. Placement and sizing these devices in suitable location can lead to control in line flow and maintain bus voltages in desired level and so improve voltage stability margins. Moreover, this adjustment can improve voltage profile system along with reducing the power system losses. This paper proposes a systematic method by which optimal location and sizing of Unified Power Flow Controller (UPF...

This paper presents a solution of the economic load dispatch (ELD) problem with security constraints of power systems, using an iterative technique based on the linear programming method, called "Successive Linear Programming" (SLP). The objective is to minimize the nonlinear function which is the total fuel cost of thermal generating units, while taking into account the security constraints (power generations, voltages and line flows). The proposed approach has been implemented on the Algerian 59-bus system. Simulation results obtained from the proposed method confirm the advantage of computation rapidity and solution accuracy. The comparison results prove the capability of the proposed method in real-time implementation for the economic load dispatch problem.

Context and Current Status of Art Due to the increasing use of electronic devices, loads are growing less resilient to transient voltage fluctuations, called voltage sag. A range of devices called Custom Power is a technologydriven product and service solution that offers functionalities for improving power quality. The dynamic voltage restorer (DVR) is the most technologically sophisticated and cost-effective device for mitigating voltage-sag in distribution systems among the various innovative custom-power devices. In order to increase voltage quality by adjusting voltage magnitude, wave form, and phase shift, the standard DVR works by injecting AC voltages in series with the incoming three-phase network. These load voltage characteristics are crucial since they have the potential to the protected load's performance. Real and reactive powers are injected into the distribution system as part of the voltagesag adjustment, which establishes the energy storage device's capacity needed for the restoration plan. The voltage source inverter of the DVR has the ability to electrically create the reactive power needed. To achieve the real-power need, an external energy storage device is required. Therefore, while evaluating a DVR's capabilities, particularly for mitigating long-duration voltage sag, the highest amount of real power that can be delivered to the load during voltagesag correction is a determining factor. Energy consumption can be decreased by using voltage injection with a suitable phase advance relative to the source side voltage. However, using will not be sufficient to meet the energy need.

This paper modeled and analyzed the reliability performance of the 132/33 kV substation in Abuja, Nigeria through the historical data collected from the APO substation using MATLAB 2021b. The probability distribution model was applied to determine the daily feeder's outage using Reliability, availability, mean time to repair (MTR), Failure rate, distribution indices, and mean time between failures (MTBF). Due to the application of smart energy meters, the use of prepaid energy meters has helped to regulate energy demand, reduce network overloading especially during peak hours, and minimize the cost of energy consumed. There are more forced failures in the distribution system due to the switchgear and Transformer failures. There are more forced failures in the distribution system since 2013, which caused a reduction in the number of interruptions even with an increase in several customers linked to the transmission network. The result shows that the system was most available in the year 2015 with an average service availability index (ASAI) value of 98.9971%. The system was least available in year 2011 with an ASAI value of 98.6558%. The paper recommended that there should be interconnections between different feeders through proper configuration of switches or reclosers, to reduce failure occurrence in the network.

Forecasting the future load growth of an area based on its load demand is often a proactive measure to ensure a steady electricity power supply to that area. The study focused on long-term load forecasting for power system planning, specifically examining the electric load demand from consumers on distribution transformers within Port Harcourt City, located in Rivers State, Nigeria. The study encompassed a comprehensive review of both statistical and artificial intelligence-based approaches. Historical load data for distribution transformer readings spanning 2008 to 2017 were acquired from the Port Harcourt Electricity Distribution Company (PHEDC) and subjected to analysis using the curve-fitting technique. For the period between 2015 and 2030, a yearly load forecast simulation was conducted using the Fourier Series model, implemented with MATLAB software. This simulation aimed to provide insights into future load demand, facilitating careful and informed decision-making in the investment, operation, and maintenance of power system equipment. The effectiveness of the forecasting investigation was assessed using the Root Mean Square Error (RMSE), confirming the efficiency, reliability, and validity of the employed model. The study's forecasted results are presented as a valuable guide and practical tool for policymakers and the utility company (PHEDC) to enhance proper planning and decision-making processes. Considering the observed trend in the results, it is suggested that installing additional transformer units in the region would be necessary to alleviate the loads on existing overloaded transformer units within the power system network.

Power system flexibility relates to the ability of the power system to manage changes. Solutions providing advances in flexibility are of utmost importance for the future power system. Development and deployment of innovative technologies, communication and monitoring possibilities, as well as increased interaction and information exchange, are enablers to provide holistic flexibility solutions. Furthermore, development of new methods for market design and analysis, as well as methods and procedures related to system planning and operation, will be required to utilise available flexibility to provide most value to society. However, flexibility is not a unified term and is lacking a commonly accepted definition. The flexibility term is used as an umbrella covering various needs and aspects in the power system. This situation makes it highly complex to discuss flexibility in the power system and craves for differentiation to enhance clarity. In this report, the solution has been to differentiate the flexibility term on needs, and to categorise flexibility needs in four categories: Flexibility for Power, Flexibility for Energy, Flexibility for Transfer Capacity, and Flexibility for Voltage. Here, flexibility needs are considered from over-all system perspectives (stability, frequency and energy supply) and from more local perspectives (transfer capacities, voltage and power quality). With flexibility support considered for both operation and planning of the power system, it is required in a timescale from fractions of a second (e.g. stability and frequency support) to minutes and hours (e.g. thermal loadings and generation dispatch) to months and years (e.g. planning for seasonal adequacy and planning of new investments). The categorisation presented in this report supports an increased understanding of the flexibility needs, to be able to identify and select the most suitable flexibility solutions.

Power system flexibility relates to the ability of the power system to manage changes. Solutions providing advances in flexibility are of utmost importance for the future power system. Development and deployment of innovative technologies, communication and monitoring possibilities, as well as increased interaction and information exchange, are enablers to provide holistic flexibility solutions. Furthermore, development of new methods for market design and analysis, as well as methods and procedures related to system planning and operation, will be required to utilise available flexibility to provide most value to society. However, flexibility is not a unified term and is lacking a commonly accepted definition. The flexibility term is used as an umbrella covering various needs and aspects in the power system. This situation makes it highly complex to discuss flexibility in the power system and craves for differentiation to enhance clarity. In this report, the solution has been to di...

Effective grounding is critical for protection of electrical equipment from transients. Grounding for personnel safety requires very distinct considerations. The application of the grounds may be similar in some instances. However, the installation will be radically different in isolated areas. Furthermore, the grounding of controls and computers present even more unusual requirements than the grounding of power devices. Additional concerns are circulating currents and injection of spurious noise. This paper addresses grounding for transients, power, and personnel. Designs include installations in plants and for isolated and remote equipment. The methods have been effectively used for pipelines, production facilities, gas plants, and power plants. Ten case studies of diverse applications illustrate the pertinence of the techniques and procedures.

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).

This paper presents an overview of the activities of the CIGRE/CIRED C1.C6.37/B5 Joint Working Group (JWG), is studying how transmission and distribution planning scenarios are consistently used to ensure holistic investment decision-making by TSOs and DSOs. The investigation is in the context of growing uncertainty in future energy scenarios due to increasing distributed energy resources (DER), electrification of transport, interconnection, consumer heating, global emissions targets, etc. The C1.C6.37/B5 JWG aims at addressing the following issues: 1) to survey and describe current practices on considering and modelling uncertainties, and risk management in generation, transmission, distribution and demand sides; 2) to survey on transmission and distribution planning under uncertainty and distributors' evaluation of recommendations on planning under uncertainty; 3) to review the investment decision making processes, for transmission and distribution, in different jurisdictions ...

Executive Summary
This part of the series translates the diagnostic findings of Part 1 into a pragmatic, 5-year strategic roadmap for the full operationalization of the Oyan Dam Hydropower Project. Leveraging global benchmarks from Bhutan, Ethiopia, and Norway, and drawing lessons from Nigeria's own Kainji Dam success story, this blueprint outlines a multi-stakeholder, phased approach. It addresses the critical barriers of expertise erosion, fiscal myopia, institutional amnesia, and stakeholder fragmentation, proposing specific interventions across legislative, technical, financial, and community engagement dimensions. The ultimate goal is to transform Oyan Dam from a symbol of neglect into a beacon of sustainable energy and economic prosperity for Ogun State and Nigeria.

Power generation in Germany is currently transitioning from a system based on large, central, thermal power plants to one that heavily relies on small, decentral, mostly renewable power generators. This development poses the question how transmission grids' reactive power demand for voltage management, covered by central power plants today, can be supplied in the future. In this work, we estimate the future technical potential of such an approach for the whole of Germany. For a 100% renewable electricity scenario we set the possible reactive power supply in comparison with the reactive power requirements that are needed to realize the simulated future transmission grid power flows. Since an exact calculation of distribution grids' reactive power potential is difficult due to the unavailability of detailed grid models on such scale, we optimistically estimate the potential by assuming a scaled, averaged distribution grid model connected to each of the transmission grid nodes. We find that for all except a few transmission grid nodes, the required reactive power can be fully supplied from the modelled distribution grids. This implies that -even if our estimate is overly optimistic -distributed reactive power provisioning will be a technical solution for many future reactive power challenges.

Power generation in Germany is currently transitioning from a system based on large, central, thermal power plants to one that heavily relies on small, decentral, mostly renewable power generators. This development poses the question how transmission grids' reactive power demand for voltage management, covered by central power plants today, can be supplied in the future. In this work, we estimate the future technical potential of such an approach for the whole of Germany. For a 100% renewable electricity scenario we set the possible reactive power supply in comparison with the reactive power requirements that are needed to realize the simulated future transmission grid power flows. Since an exact calculation of distribution grids' reactive power potential is difficult due to the unavailability of detailed grid models on such scale, we optimistically estimate the potential by assuming a scaled, averaged distribution grid model connected to each of the transmission grid nodes. We find that for all except a few transmission grid nodes, the required reactive power can be fully supplied from the modelled distribution grids. This implies that -even if our estimate is overly optimistic -distributed reactive power provisioning will be a technical solution for many future reactive power challenges.

In this paper a comprehensive review of electrified railway systems is carried out, identifying the electric power quality deterioration which may appear due to nonlinear dynamic traction loads. Following this topic, a computational simulation of Static Synchronous Compensator (STATCOM) and Rail Power Conditioner (RPC) are presented, making a comprehensive analysis of each of these solutions regarding the power quality improvement in electrified railway systems. Four case studies are presented: (i) STATCOM evaluation when a traction power system is fed by a V/V power transformer; (ii) STATCOM evaluation when a traction power system is fed by a Scott power transformer; (iii) RPC evaluation when a traction power system is fed by a V/V power transformer; (iv) RPC evaluation when a traction power system is fed by a Scott power transformer.

The increasing consumer demand for sustainable textiles has led companies to invest in organic and recycled materials while adopting green manufacturing processes to reduce their environmental footprint. The textile industry is exploring innovative approaches such as upcycling and green chemistry to regenerate textile waste fibers sustainably. And these efforts are aimed at transforming the fashion and textile industry towards a more sustainable and eco-friendly future. To achieve this the textile industries, have to leverage on the technological advancements available which one of it is, various applications of ML models for a more accurate and efficient results. This study focused on the application of a hybrid machine learning model which is the combination of Seasonal Auto-Regressive Integrated Moving Average (SARIMA) model and Long Short-Term Memory (LSTM) networks for Accurate Production Forecasting in Textile Industry. Research studies reviewed gave important insights into the study. This study adopted a quantitative research approach, using a five-year historical production data from a textile company to train and evaluate the hybrid ML model. The research design includes data collection, preprocessing, model training, evaluation, and comparative analysis. The research analysis presents a well-performing predictive model, as evidenced by the high R-squared value of 0.87, relatively low root mean squared error (RMSE) of 1.23, low mean squared error (MSE) of 1.51, and low mean absolute error (MAE) of 0.98. However, the residual time series and the predicted and actual values plots suggest possible degradation in the model's performance over time.

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E possivel encontrar sistemas de equacoes lineares associados diretamente a situacoes em varias areas de estudo, como por exemplo, administracao, economia, engenharia, ciencia da computacao, entre outros. Os metodos numericos tem o objetivo de nos auxiliar na obtencao das solucoes desses sistemas de equacoes lineares. Conforme [2], os metodos de Sub e Sobre Relaxacao Sucessiva sao estacionarios e derivados do metodo de Gauss-Seidel, tendo como diferencial um fator de correcao ω que e aplicado na funcao de iteracao do metodo de Gauss-Seidel com o objetivo de acelerar a convergencia. A equacao de iteracao dos metodos de relaxacao sucessiva e dada por: [...]

Protection of equipment insulation against lightning over voltages and selection of lightning arrester for 220 kV substations that will discharge at lower voltage level than the voltage required to breakdown the electrical equipment insulation is examined. The objectives of this paper is to select appropriate lightning arrester with the lowest rated surge arrester that will provide adequate protection of equipment insulation and equally have a satisfactory service life when connected to a specified line voltage in power system network. The effectiveness and non-effectiveness of earthing system of substation determines arrester properties. Also Standards recognize that particular attention is required for the earthing of surge arresters. A MATLAB program is used in the development of model for the determination of Surge arrester grounding grid parameters like calculation of tolerable limits of current to the body, typical shock situations, tolerable touch and step voltages, maximum f...

There are problems with congestion during peak electricity demand periods for today's grid infrastructure. As the demand has been sharply increasing day by day, the power reserve, as it is designed today, may be gradually phased out. Demand side management (DSM) can then be necessary to keep balance between the demand and the supply. By using Smart Meters (SMs), the Distribution System Operator (DSO) can manage the demand side during peak load crisis and decrease the risk of blackouts. The SM may allow the DSO to switch loads in an area using a customer's prioritize list, while excluding emergency service providers and critical customers from switching. Moreover, switching multiple SMs at a time might have impact on the Power Quality (PQ) of the grid. This paper presents results from field test on multiple SMs switching and investigated the impact of SMs switching on the PQ of the electricity grid.

Phyto-electricity is the process of generating or getting energy from green plants by using them as an electrolyte and inserting different metal plates in them to act as electrode in other to tap into the energy embedded in them and converting them to useful electric energy. Nowadays generating electricity from green plant has become very popular, but phyto-electric power generation has not been able to supply substantial energy to humans and this is due to the low electron in the plants used to generate electricity. In past research people have used trees to generate electricity. The phyto-electric power system works on same principle as the battery. In this design potato will be used as a source of power or as the green plant the battery which is filled with electrolytes, the more the electrolyte the higher the voltage that is readily available to be used, in other to be able to savor the power from the potato two dissimilar metals was used and the metals used were iron and zinc. After completing all of the paper design and analysis, the project was implemented, built, and tested to guarantee that it functioned properly. Electricity was generated and it was used to power a LED, the total resistance of the wire is 1Ω, there is also voltage loss across each node. This project was a success, but more research still needs to be done. And this project is a prove that energy are available in our surroundings, they are just needed to be investigated and further researched and there are more areas of energy and technology development that are yet to be addressed that are various problems faced by man in his day to day activities.

Power quality is one of the major problems in the present era. It has gained its importance because of the introduction of the sophisticated devices, whose performance is very sensitive to quality of power supply. Power quality problem is an occurrence manifested as a nonstandard voltage, current or frequency that results in a failure of end user equipment. One of the major problem dealt here is the voltage sag of the multiline power system. The aim of this paper is to design an Interline Dynamic Voltage Restorer which is able to compensate voltage sag and voltage regulation at critical load terminals. In our project, the Interline Dynamic Voltage Restorer (IDVR) has two IDVRs are connected to a common DC Link with Adaptive Neuro-Fuzzy Inference System (ANFIS). One of the IDVRs compensates for a voltage sag, the other IDVRs connected to common DC-Link energy storage. A current mode control strategy is incorporated into the IDVR system in both the working modes, voltage sag compensat...

This paper presents a methodology that has been developed by Electric Power Research Institute (EPR I) to perform the technical and cost/benefit analysis of realizing the potential solution opportunities of e nergy storage within distribution. The methodology develo ped was built in terms of identifying and characterizin g feeder contrainsts. Key elements of the overall methodology are presented in this paper. This methodology is now being tested through case studie s in several utility situations.Results from one example case study is presented in the paper.

This paper addresses the counter-intuitive phenomenon of phase current reduction in a three-phase system with asymmetrical tap changer positions. Specifically, the study examines cases where a transformer's phase B tap is stuck and is unable to switch while phases A and C are at lower taps. The results from simulations show that increasing the tap position on phase B, which would normally be expected to increase the current in that phase, leads to a reduction of current in phase A. It is demonstrated that this behavior can be attributed to the generation of a significant zero sequence current component. It flows through the earth and neutral path and, by its interaction with the other phase currents, reduces the magnitude of the current on phase A. This paper provides both theoretical and simulation results to illustrate that unbalanced tap settings are a common cause of zero-sequence currents, and their effect on individual phase currents. The implications of this phenomenon on power system performance and protection are also discussed.

The experience and intelligence of human are necessary to fulfill the hazardous and responsible operations by mobile robot in undetermined environment. To make the control process more effective and simple for human the speech control may be used. The operator's interface in this case may be created using the linguistic variables both for commands formalization and for information presentation. The speech controlled robot has to be an autonomous intelligent system capable to re-cognize the current situation and to adopt its behavior to real environment. To adopt the artificial intelligence to the human impression and reasoning the fuzzy logic principles may be used to create the knowledge base of a speech controlled robot. The simple manipulation and locomotion operations may be presented in form of fuzzy production rules. For complicated modes of behavior the procedure of fuzzy AI -planning have been proposed. The procedure of robot learning on the base of fuzzy neural networks has been developed .for the situations when human-operator can not formalize the fuzzy rules of robot behavior beforehand.

Solar energy, one of the fastest-growing renewable resources, holds immense potential for transforming global energy systems. However, its seamless integration into smart grids introduces complex technical and regulatory challenges. This research critically examines the integration of solar energy into smart grids, focusing on the multifaceted challenges and opportunities associated with enhancing grid efficiency, ensuring stability, and navigating regulatory frameworks. Data were meticulously gathered from 10 pioneering smart grid projects across 5 distinct regions over 12 months at the College of Engineering, Lamar University, USA, from June 2023 – June 2024. Employing a mixed-methods approach, the study combines rigorous quantitative analysis of grid performance data with in-depth qualitative interviews of 30 industry experts. Key metrics include energy efficiency improvements, grid stability fluctuations, and storage capacity challenges. The integration of solar energy led to a remarkable 28% increase in grid efficiency and an 18% reduction in carbon emissions across the evaluated projects. Nonetheless, 72% of the grids faced significant voltage instability due to the intermittent nature of solar power, and 65% required substantial investments in advanced storage technologies to ensure reliability. Moreover, 75% of stakeholders cited inadequate policy support as a key barrier to broader solar integration. Solar energy integration into smart grids offers transformative opportunities for enhancing energy sustainability. However, addressing technical barriers such as intermittency, investing in storage solutions, and fostering more progressive regulatory environments is imperative for realizing its full potential.

The "Bremen Energy Working Papers" are published by Jacobs University Bremen. The papers feature research and scholarship of a preliminary nature that should encourage dialogue and critical discussion. The content does not necessarily reflect the views of Jacobs University Bremen and is the sole responsibility of the authors. Jacobs University Bremen does not bear any responsibility concerning the contents.

The high level of technical and non-technical losses in power distribution systems contribute immensely to the inefficiency of energy supply and poor revenue in the power system. Reducing losses therefore is a necessary objective in the management of any electrical utility. This paper describes the context of losses in power distribution systems and investigates methods of reducing such losses. The power flow solution of the radial network was obtained and the losses computed. The use of capacitor placement to reduce transmission losses was investigated. Results show that high technical losses are as a result of poor management practice.

The computer aided design/ computer aided manufacturing (CAD/CAM) linkage has greatly shortened the period between design and manufacture and has greatly expanded the scope of production processes. In this paper, a computer aided process planning/ computer aided fixture design/ computer aided inspection planning (CAPP/CAFD/CAIP) system is proposed for CAD/CAM integration. The object oriented approach is applied for integration and automation of CAPP/CAFD/CAIP modules. The proposed system is suitable for 3-D manufacturing parts that are created by using a solid modeling package. The STEP AP 203 E2 is used as input to the integrated system. The CAPP module contains data extraction, feature recognition and process planning files. The setup plans are created separately for CAFD and CAIP. The modular fixture design is established from the manufacturing setup plan using search strategy and graphical database. The CAIP module then produced inspection plan and Dimensional Measuring Interfac...

Protection of equipment insulation against lightning over voltages and selection of lightning arrester for 220 kV substations that will discharge at lower voltage level than the voltage required to breakdown the electrical equipment insulation is examined. The objectives of this paper is to select appropriate lightning arrester with the lowest rated surge arrester that will provide adequate protection of equipment insulation and equally have a satisfactory service life when connected to a specified line voltage in power system network. The effectiveness and non-effectiveness of earthing system of substation determines arrester properties. Also Standards recognize that particular attention is required for the earthing of surge arresters. A MATLAB program is used in the development of model for the determination of Surge arrester grounding grid parameters like calculation of tolerable limits of current to the body, typical shock situations, tolerable touch and step voltages, maximum f...

This paper presents an approach for assessing, in operation planning studies, the security of a large-scale power system by decomposing it into elementary subproblems, each one corresponding to a structural weak-point of the system. We suppose that the structural weak-points are known a priori by the system operators, and are each one described by a set of constraints that are localized in some relatively small area of the system. The security analysis with respect to a given weakpoint thus reduces to the identification of the combinations of power system configurations and disturbances that could lead to the violation of some of its constraints. We propose an iterative rare-event simulation approach for identifying such combinations among the very large set of possible ones. The procedure is illustrated on a simplified version of this problem applied to the Belgian transmission system.

To solve the optimization problem of Economic
Load Dispatch (ELD), a number of metaheuristic approaches
have already been implemented, exhibiting substantial
improvement over the conventional technique. Despite this, due
to the global energy crisis, research in ELD still continues to
garner considerable interest. In this study, the Seagull
Optimization Algorithm (SOA), a recently developed swarm
intelligence technique, is applied in ELD. As the SOA algorithm
has never been utilized in the ELD, it is important to investigate
its efficacy and validity in this domain. Here, two case studies of
ELD incorporating 6 and 10 generator units are implemented
employing SOA. What’s more, the performance of SOA in ELD
is compared with respect to three other previously applied
metaheuristics algorithms. Results indicate that SOA is a
potential algorithm capable of handling the practical
optimization challenge of ELD problem more effectively,
especially in large power plants having more than 6 units.

Optimization plays a crucial role in economic load dispatch (ELD) due
to the rising competition in the electricity market. In dealing with complex and
challenging optimization problems, swarm intelligence has already demonstrated its
skill. Hence, in this study, the optimization of non-smooth economic load dispatch
(ELD) has been implemented by employing two popular metaheuristic algorithms,
namely Artificial Bee Colony (ABC) and Genetic Algorithm (GA). However, before
implementing a metaheuristic algorithm, it is crucial to understand how it performs in
contrast to others. Owing to this, the comparative study between these two algorithms
(ABC and GA) in terms of convergence characteristics, statistical performance, and
computation time in ELD is outlined. The results reveal that ABC outperforms GA
in the ELD problem when it comes to minimizing fuel costs, despite the fact that
ABC’s computational time is slightly longer than that of GA.

The operation of transmission networks is made depending on their loads - distribution system. Transmission systems are optimized to ensure loads and generation from EHV, HV and MV. The connection of DG units to distribution networks can impact the planning and operation of transmission systems. When these units are predominantly from renewable sources, given their intermittency or derived from disturbances, they may temporarily disappear causing potential problems on the balance between loads and generation. This paper addresses the challenges that DG units may cause on distribution and transmission networks and, hence, the need for information exchange between DSO and TSO. An example of a real implementation is detailed and the quantity and type of information valuable for both system operators is explained.

The distribution of electrical energy to end-users in Nigerian communities is faced with diverse spatial problems leading to low voltage, overload on equipment, difficulties in fault tracing and delay in fault clearing. The traditional management system is not only manual but also has flaws such as difficulties in searching and updating previous records as well as no real-time information on their distribution assets. In this study, a geospatial technique was employed for effective management of the electricity distribution system in Malete, Kwara State, Nigeria. Spatial information of distribution asset was collected from the field and used in the structural modelling of the distribution network in the ArcMap software. Analysis of the model and the available information showed that 80 % of the transformers were not properly located at the centroid of the load. The span of the network fairly conformed to standard as only 45.73 % were within 45-50 m. The result also showed that 40 % of the transformers were overloaded with an unbalanced load, hence the need for restructuring of the network

The main aim of the contribution is verification of designed principle for earth fault location in real distribution network which is based on evaluation of voltage sags recorded on secondary side of distribution transformers MV/LV. For this purpose, series of experimental measurement in real compensated MV distribution network were carried out. During the experiments, different types of earth fault (solid, arcing and impedance earth fault) were artificially ignited and all important waveforms (secondary voltages of distribution transformer, fault currents, voltages and currents at supply substation) were recorded for further analyses. These fault records were used for verification of described method. The result of the analyses is answer to question, if it is possible to use the idea of earth fault localization method in real conditions of compensated distribution network operation. INTRODUCTION The requirement to monitor the characteristic parameters of electrical energy and the e...

Os problemas de programação semi-infinita (PSI) aparecem nas mais diversas áreas da Engenharia, tais como, no planeamento da trajectória de robôs, no controlo da poluição atmosférica, no planeamento da produção, no desenho óptimo de conjuntos de sinais e desenhos de filtros digitais. Esta tese é dedicada a problemas de PSI não linear na sua forma mais geral. Os problemas considerados são caracterizados por possuírem um número finito de variáveis e um conjunto infinito de restrições. Os métodos numéricos existentes para a resolução de problemas de PSI podem ser divididos em três classes principais: métodos de discretização, métodos das trocas e métodos de redução. Os métodos de redução são os que possuem melhores propriedades teóricas de convergência. São, também, os mais exigentes em termos numéricos uma vez que exigem a resolução de problemas auxiliares, em que se pretende a determinação de todos os óptimos globais e locais (optimização multi-local). Nas últimas décadas foram apresentados vários algoritmos para problemas de PSI. Contudo há pouco software disponível e nenhum fornece uma implementação de um método pertencente à classe de redução. Neste trabalho é proposto um algoritmo de redução local baseado na técnica de penalidade. A função usada considera uma extensão de uma função de penalidade de norma-∞ aumentada. A escolha desta função de penalidade para propor a extensão às restrições finitas deve-se à obtenção de melhores resultados numéricos para um conjunto de problemas vii viii RESUMO teste de PSI sem restrições finitas, em comparação com as funções de penalidade baseadas na norma 1, 2 e ∞ da violação das restrições. Fez-se o estudo das propriedades teóricas da função de penalidade estendida. É feita uma implementação do algoritmo de redução local proposto. O solver desenvolvido é designado por SIRedAl (Semi-Infinite Reduction Algorithm). Este solver foi implementado em MATLAB e é capaz de resolver problemas de PSI na forma mais geral com dimensão infinita máxima de 2. O código do solver usa dois algoritmos diferentes na minimização da função de penalidade e dois na resolução dos problemas multi-locais. O solver foi testado com 117 problemas teste da base de dados SIPAMPL e os resultados numéricos confirmaram a potencialidade do algoritmo proposto.

This paper will discuss about impact of nonlinear load in residential costumer to harmonic distortion. Electricity consumer behaviour particularly in the household sector with the development of technology will evolve. Equipment used for everyday purposes continues to grow and has become a lifestyle. The modern life is becoming fabulous with the invention of new technology, so that many more electricity utilities are used by people and their houses in daily life. Nowadays, loads in the housing electricity utility do not only contain of linier loads, but also non-linier loads such as television, computer, microwave, fluorescent lamp and so on. The problem uses nonlinear load is create harmonic distortion. The harmonic distortion will reduce the life time of electrical equipment and inefficiency. The purpose of this research is to do modelling and prediction of harmonics level on housing electricity utility. The modelling and prediction of this research was using harmonic analysis wit...

Abstract: The most rational mode of communication between intelligent robot and human-operator is bilateral speech dialogue using a problem-oriented language. The dialogue mode of control raises the problem of compliance between the human and robot perception of external world, logic, behavior planning and decision making. We suppose that linguistic variables and fuzzy logic is the most suitable approach for the mentioned problems. The model of the world formed on the base of natural space-time relations allows formulating the basic robot operations in terms of linguistic variables and to solve the problem of planning of robot behavior in previously undetermined environment. Using the fuzzy neural networks it is possible to train robot to fulfill complicated operations by human-operator. Relationship between fuzzy logic approach and the procedures of speech recognition are also under consideration

Power systems may not capable of utilizing full transmission capacity. Restructuring of electricity industry produces some management criteria to improve technical as well as economical efficiency. The process of reregulation causes more challenges with regards to technical and trading issues. Under the new scheme of power markets, congestion management is a crucial problem that needed to be considered. Congestion relief can be handled using FACTS devices, where transmissions capability will be improved. In this paper, real genetic algorithm (RGA) is used for optimization process while analytical hierarchy process (AHP) with fuzzy sets is implemented to evaluate RGA fitness function. The effectiveness of the proposed methodology is shown through a modified IEEE 5-bus system.

Supply interruptions depend on the reliability of the entire power system comprising a generation system and transmission and distribution networks. Transmission system faults quite rarely result in customer interruptions, but if they occur the number of customers affected can be higher than in case of distribution system faults. This is the reason why it is important for the reliability of the transmission system to be on a high level. On the other hand, generation faults are not so frequent, but even if they occur the system is controlled and remains balanced. In this paperwork, reliability indices were evaluated for one part of modelled composite power network in Bosnia and Herzegovina (BIH) to which, in addition to conventional power plants, renewable sources were connected including the first wind farm which is under trial operation at present. Both simulations and the composite network were created using DIgSILENT PowerFactory 18 software package for the regimes of minimum and maximum system load in the observed year with the aim of obtaining relevant reliability indices in order to examine the impact of the wind farm in BIH on system reliability. Subsequently, reliability evaluation at hierarchical level 2 (HL II) was discussed.

This paper develops a two-stage model for planning of the hub, taking into account various uncertainties, in which the sizing of hub converters is performed with the aim of improving hub resilience. In the first stage, the capacity of hub converters is selected and in the second stage, the operation problem is solved under N-1 contingency conditions. In the proposed model, Price-based demand response (DR) and direct load control (DLC) programs are considered to implement in normal and emergency situations, respectively. The robust optimization method is utilized to deal with the uncertainties the problem is formulated as a mixed-integer non-linear programming (MINLP) problem. Finally, DICOPT solver in GAMS environment is used to solve the model and the results demonstrate that considering the N-1 contingency conditions in the design problem leads to the installation of more converters as well as larger capacities. The results also indicate that the operating cost of the hub during the outage condition of combined heat and power (CHP) is reduced by 63.48% through the implementation of the DLC program considering energy storage system. Overall, the results illustrate that considering the emergency operating conditions in the hub design problem, leads to a significant enhancement in its resilience.

GSM Network in Nigeria in recent times has been epileptic due to drop in signal strength, which causes customer dissatisfaction with the quality of service delivery by network operators. University of Maiduguri has experience low signal quality in recent years due to frequent dropped calls, poor network interconnectivity, echoes and network congestion, therefore this work presents a detail analysis of the received GSM signal strength in university of Maiduguri. An android application program known as network cell info Lite was used for the measurement of signal strength for three different network in the university at random sampling points. The three network considered are: Network A, Network B and Network C, in three different locations; Academic area, student hostel and staff quarters within the university. The data collected were analyzed using SPSS Statistical tool. The mean value of the signal strength received using the software application shows that Network A with HSPA -91....

A constant power supply is a key indicator of a developed economy. Any nation with unreliable energy supply hampers its development and risks losing potential investors. Nigeria, a country with over 160 million people, has experienced frequent and persistent power outages over the past 33 years since the establishment of the National Electric Power Authority (NEPA), the agency responsible for electricity generation, transmission, and distribution. Currently, the federal government is implementing power sector reforms aimed at improving this unfavorable situation and reducing the monopoly control over the country's power industry. This paper examines the overall power sector and its reforms, evaluates the opportunities and challenges, and advocates for the introduction and effective management of National Integrated Power Projects (NIPPs) and Independent Power Producers (IPPs) as positive steps forward.

Background and Objectives: Distributed generations (DGs) based on renewable energy, such as PV units, are becoming more prevalent in distribution networks due to technical and environmental benefits. However, the intermittency and uncertainty of these sources lead to technical and operational challenges. Energy storage application, uncertainty analysis, and network reconfiguration are apt therapies to resist these challenges. Methods: Energy management of modern, smart, and renewable-penetrated distribution networks is tailored here considering the uncertainties correlations. Network operation costs including switching operations, the expected energy not served (EENS) index as the reliability objective, and the node voltage deviation suppression as the technical objective are mathematically modeled. Multiobjective particle swarm optimization (MOPSO) is considered as the optimization engine. Scenario generation method and Nataf transformation are used in probabilistic evaluations of the problem. Moreover, the technique for Order Preference by Similarity to the Ideal Solution (TOPSIS) is deployed to make a final balance between different objectives to yield a unified solution. Results: To show the effectiveness of the proposed approach, the IEEE 33-node distribution network is put under extensive simulations. Different cases are simulated and interrogated to assess the performance of the proposed model. Conclusion: For different objectives dealing with different aspects of the network, remarkable achievements are attained. In brief, the final solution shows 4.50% decrease in operation cost, 13.07% improvement in reliability index, and 18.85% reduction in voltage deviation compared to the initial conditions.

Forecasting the future load growth of an area based on its load demand is often a proactive measure to ensure a steady electricity power supply to that area. The study focused on long-term load forecasting for power system planning, specifically examining the electric load demand from consumers on distribution transformers within Port Harcourt City, located in Rivers State, Nigeria. The study encompassed a comprehensive review of both statistical and artificial intelligence-based approaches. Historical load data for distribution transformer readings spanning 2008 to 2017 were acquired from the Port Harcourt Electricity Distribution Company (PHEDC) and subjected to analysis using the curve-fitting technique. For the period between 2015 and 2030, a yearly load forecast simulation was conducted using the Fourier Series model, implemented with MATLAB software. This simulation aimed to provide insights into future load demand, facilitating careful and informed decision-making in the investment, operation, and maintenance of power system equipment. The effectiveness of the forecasting investigation was assessed using the Root Mean