Distribution Network Losses Research Articles

Impact of small hydro generation on voltage profile and losses in 20 kV distribution network

Planning in the development of electricity availability focuses on Renewable Energy power plants in support of the Government’s strong determination to suppress fossil-based energy and increase in New Renewable Energy whose mix is targeted to reach 23% in 2025. Distributed generation (DG) is one of the new approach in the installation of power plants which the plant location is no longer centralized, but it was spread on the distribution of electricity networks. Nowadays, the application of distributed generation has increased because it is a renewable energy especially small hydro of distributed power plants can affect the conditions of the distribution network. Therefore, it is necessary to know the impact of the installation of distributed power plants. This study was conducted to analyze the effects of DG connected to network at two conditions First, the distributed generation connect when under load condition in network and second, distributed generation connect when peak load condition in network. Simulation in this study was conducted using the ETAP software and The Newton-Raphson method has been used in order to calculate power losses and voltages across the network with real data of rural distribution network in Tanah Jawa, North Sumatera, Indonesia. The 20kV distribution network was used in this feeder, and it was divided into one main feeder. The results of this study are expected to provide information about the impact of the DG on voltage and power losses in distribution network. The results of the study show that the installation of DG enhances the voltage profile and ready for installation Small Hydro as DG.

An improved metaheuristic method for simultaneous network reconfiguration and distributed generation allocation

A new chaotic search group algorithm (CSGA) is proposed in this study for simultaneous network reconfiguration and allocation of distributed generation (SNR-DG) problem with the objective of minimum real power loss in the radial distribution network (RDN). The CSGA is an improved metaheuristic algorithm, in which a chaotic local search strategy is incorporated with the original SGA, to enhance its search performance. The proposed CSGA was studied on 33-, 69-, 84- and 118-bus RDNs with three load levels. After SNR-DG application, the voltage profile and real power loss of the system had enhanced significantly. The outcomes yielded by CSGA were compared with those obtained from the original SGA and other techniques depicted in the literature. The comparative findings revealed that CSGA yielded better solution quality than SGA and other techniques. Hence, CSGA is the best technique to address the SNR-DG problem in RDNs.

Probabilistic Minimum Night Flow Estimation in Water Distribution Networks and Comparison with the Water Balance Approach: Large-Scale Application to the City Center of Patras in Western Greece

Quantification of water losses (WL) in water distribution networks (WDNs) is a crucial task towards the development of proper strategies to reduce them. Currently, WL estimation methods rely on semi-empirical assumptions and different implementation strategies that increase the uncertainty of the obtained estimates. In this work, we compare the effectiveness and robustness of two widely applied WL estimation approaches found in the international literature: (a) the water balance, or top-down, approach introduced by the International Water Association (IWA), and (b) the bottom-up or minimum night flow (MNF) approach, based on a recently proposed probabilistic MNF estimation method. In doing so, we use users’ consumption and flow-pressure data from the 4 largest pressure management areas (PMAs) of the WDN of the city of Patras (the third largest city in Greece), which consist of more than 200 km of pipeline, cover the entire city center of Patras, and serve approximately 58,000 consumers. The obtained results show that: (a) when MNF estimation is done in a rigorous statistical setting from high resolution flow-pressure timeseries, and (b) there is sufficient understanding of the consumption types and patterns during day and night hours, the two approaches effectively converge, allowing for more reliable estimation of the individual WL components. In addition, when high resolution flow-pressure timeseries are available at the inlets of PMAs, the suggested version of the bottom-up approach with probabilistic estimation of MNF should be preferred as less sensitive, while allowing for confidence interval estimation of the individual components of water losses and development of proper strategies to reduce them.

Power losses evaluation in low voltage distribution network: a case study of 250 kVA, 11/0.416 kV substation

Nowadays, the electrical system is more complicated duet to the continuous growing. Power losses is the biggest challenges for distribution network operators. There are several causes for technical losses. Losses caused by unbalanced phase current are one of the main reasons which can be minimized by small investment through dedicating a technical line staff. As a result of connecting many single loads to three phase four wire power supplies, the current flowing in each phase will be unequal and accordingly there will be a current flowing in the neutral wire. Unbalancing currents in phases can lead to increase the conductor temperature and accordingly the conductor resistance is higher which contribute to increase the power losses. Loss reduction can lead to enormous utility saving. Besides, it increases system capacity and save more money which can be used later for future planted system. This study concentrated on the amount of copper losses in distribution networks as a result of unequal loading of the three phases four wires network. The distribution network is more efficient and more economic assuming that the right procedure is applied to balance the distribution system and achieve the required calculations which require a little investment.

Multi-Objective Optimization for Optimal Allocation and Coordination of Wind and Solar DGs, BESSs and Capacitors in Presence of Demand Response

The renewable energy sources (RES) based distributed generations (DGs) have been proven to be of great technical and economic benefits if optimally allocated in distribution networks. Their proper deployment is usually made in conjunction with demand response (DR) programs and renewables curtailment to match the demand load with the available generated power. Battery energy storage systems (BESSs) and capacitor banks (CBs) are two other tools that can compensate for the shortcomings of the RES. BESSs could complement the renewables generation intermittency and improve the reliability of the system while CBs could indemnify the limited reactive power support of the RES and improve the power quality of the system. Thus, the simultaneous integration of RES-based DGs, DR, BESSs, CBs, and curtailment could have great benefits if optimally planned and coordinated. In this paper, a multi-objective optimization planning model is formulated to determine the optimal locations and capacities of different RES-based DGs, BESSs, and CBs in presence of DR and renewables curtailment to maximize the economic index and the average voltage stability factor, and to minimize the average power losses in distribution networks. The modelling of RES-generated power is considered. The proposed model is implemented and tested on standard IEEE 33-bus radial distribution system, the model is formulated and solved in GAMS environment. Different renewable configurations and test cases are investigated. The obtained results validate the effectiveness of the simultaneous integration of the used tools in optimizing the techno-economic benefits.

Analysis of Distributed Generation Integration Effect on Active Power Losses in Distribution Networks

Distributed Generation (DG) is commonly used to reduce active power losses on a distribution network. The optimal location and size of DG will result in minimum active power losses and voltage profile improvement. This research proposes Novel Voltage Sensitivity Index (NVSI) and Stability Index (SI) methods to determine the optimal location and analytical expression to find optimal size and location of DG in Makassar distribution system, Feeder Kima, 76 buses to minimize active power losses and to improve voltage profile. Therefore, DG interconnection has a significant effect on improving the quality of the distribution network. The results show that the sensitivity method does not lead to the best placement DG in reducing active power losses. However, it is an analytical expression, which is very effective in determining optimal location and size of DG to reduce active power losses and to improve voltage profile in Makassar distribution system, Feeder Kima, 76 buses. The most optimal location for DG placement is on Bus 73 (Mega Sakti Pyramid), with a DG size of 0.8515MW. These combinations reduce 45.77% active power losses and increase 1.7336% voltage profile.

Poboljšanje rada distributivne mreže u uslovima velikih opterećenja korišćenjem fotonaponskih i sistema za skladištenje energije

This paper considers the improvement of distribution network operation in high load conditions using photovoltaic (PV) and energy storage systems (ESS). Optimal locations and powers of PV systems and ESS, considering the improvement of distribution network operation, are determined by metaheuristic optimization method of genetic algorithm (GA), where losses in distribution network and its voltage profile are used as quality indicators for distribution network operation. Two approaches are used to determine the optimal power of PV system during the day, depending on the ratio of injected power into the network by the PV system and its maximum available power at a given time. Cases with different load distributions in the distribution network are analyzed, as well as the cases with different number of connected PV systems and ESS. Based on the obtained results, in addition to determining the level of distribution network operation improvement, conclusions are given regarding the impact of load diagram on the number, location and size of PV systems and ESS.

Estimation of Electricity Losses in Distributed Electricity Network Using an Improved Three Mode Method

Abstract Increasing the energy efficiency of electricity distribution networks is the commitment of all national and private electricity distribution companies. One of the basic goals is to reduce losses in electricity distribution networks. It is known that losses in the distribution network can be defined as the differences between taken and delivered electricity. Determining losses has several basic tasks. The first task is to determine the difference between the calculated losses and the actual losses, and to determine the reason for this difference and to determine the necessary guidelines for taking measures to reduce losses. The second task is to estimate the loss index for planning and formulating different plans. This paper presents a new approach to reduce the error between calculated and actual losses using a new method based on the Three Mode method. The main purpose of the study was to investigate the power losses in distribution area. The method proposed in this paper significantly reduces the error compared to the classical Three modes method, which is the original contribution of this paper.

Evaluation of 20 kV Distribution Network Losses In Radial Distribution Systems Due to Distributed Generation Penetration

The installation of distributed generation with renewable energy becomes a solution when the demand for electricity is increasing and electricity generation with fossil energy is increasingly limited. There has been a change in power flow before and after the installation of distributed generation. However there can be a negative impact on the distribution network losses applicable to reactive power flows. There are cases where the distributed generation capacity is greater than the supplied load, resulting in distributed generation operating as a system voltage regulator and requiring reactive power, so that DG will absorb the reactive power from the system. The increasing demand for reactive power in DG also causes an increase in the current flowing in the network, and causes an increase in losses in the network, especially for the losses in reactive power.

Improving Electricity Theft Detection using Combination of Improved Crow Search Algorithm and Support Vector Machine

Energy losses in the electricity distribution and transmission network and electricity theft detection are major challenges of electricity suppliers around the world. Advanced metering infrastructure (AMI) is an essential segment of the smart grids that is responsible for gathering, measuring and analyzing consuming data of customers. The addition of a security layer to AMI has paved the way for the electricity theft in new ways. The analysis of consumed data related to users is one of the essential resources to identify electricity thieves. In this paper, the crow search algorithm (CSA) is improved and the factors of weight (w ) and awareness probability (AP ) are obtained dynamically and used to adjust the parameters c and γ of support vector machine (SVM). The results illustrate that the ICSA-SVM framework has acceptable performance and detects fraudulent customers with a high accuracy.

Robust Regional Coordination of Inverter-Based Volt/Var Control via Multi-Agent Deep Reinforcement Learning

Inverter-based Volt/Var control (VVC) methods can effectively address issues of voltage deviations and constraint violations, as well as reduce network power losses in active distribution networks. Conventional VVC mainly relies on rule-based, mathematical, or heuristic methods. However, these methods can be inefficient or even infeasible for large-scale systems, especially when operational uncertainties are considered at both spatial and temporal scales. To this end, firstly, this paper formulates a multi-region coordinated VVC optimization problem to simultaneously minimize bus voltage deviations and network power losses. Furthermore, with the problem being formulated as a partially observable Markov Game, a multi-agent deep deterministic policy gradient (MADDPG) algorithm is modified to solve this problem. Each region, which is a sub-network with a control center, is modeled as an agent and learns to optimize inverter reactive power output setpoints through exploration in virtual environment and improved neural network training procedure. Spatial and temporal uncertainties of photovoltaic power generation and loads are modeled by stochastic programming as scenarios in the MADDPG algorithm. This algorithm can address the uncertainties to guarantee solution robustness. Thus, this paper eventually proposes a robust regionally coordinated VVC method, and numerical simulations indicate high computing efficiency and robust optimum.

Method to determine fact and place of commercial losses in distribution networks

The improvement of methods to register the commercial losses in electrical distribution networks, and especially in low voltage networks, is one of the most important tasks for power supply providers. It is rather difficult to correctly register the fact of occurrence of such losses in the network. It is objectively impossible to analyze the state of the networks based on data obtained from various points of the specified network with the required accuracy. In this regard, at present no methods have been developed for remote detection of the fact and determination of the place of commercial losses in distribution networks, that could work in the mode of integration with automated information-measuring system of fiscal electricity metering. To solve this problem a method is to be developed that allows us to establish accurately for practical purposes the volume of commercial losses in the network and determine the place of their occurrence. During the research, methods of electric power networks modeling have been used. The assumption has been made about no flow of capacitive leakage currents to ground in the network, about full compliance of the line parameters with their calculated (nominal) values, as well as the basic laws of electrical engineering science. A unique method is proposed to determine the fact and the place of commercial losses in distribution networks. In contrast to the prototypes, it is based on the analysis of data obtained from metering devices, based on the key laws of electrical engineering and it allows us to get reliable arithmetically rigorous results without using fuzzy logic. The authors have proved theoretically and practically the effectiveness of the proposed solutions, and the possibility of their application. A calculation has been made to determine the place of commercial losses in the network using an example. The proposed method to determine the fact and place of commercial losses in distribution networks of low and medium voltage levels solves the problem of inability to effectively identify the points of occurrence of commercial losses in distribution networks. The reliability of the results obtained is confirmed by mathematical rigor of the method and algorithmic nature of the procedure for analyzing the distribution network.

Studi Rekonfigurasi Sistem Distribusi Pada Jaringan 20 kV Dengan Metode Simple Branch Exchange Pada Penyulang Cempaka

The increasing electric energy consumption must be balanced with good electricity network quality. To overcome this, we need a distribution network reconfiguration. Reconfiguration in power distribution network is done to improve power distribution network quality. Problem that exist in the radial distribution network is power losses. To minimize the power losses can be overcome by compensating capacitor. Done by determining the location of capacitors in distribution networks. With that the capacitor compensates the distribution network is more effective and efficient in distributing power. In this research discusses the network reconfiguration using simple branch exchange method to reduce power losses in radial distribution networks. The reconfiguration method was carried out with the help of the Electrical Transient Analysis Program (ETAP) 12.6.0 software and has been tested by PT REKAYASA INDUSTRI and PLN Area South Kalimantan on the 20 kV distribution system of Cempaka feeder, South Kalimantan. With this reconfiguration, the voltage drop that occurs on several buses, especially bus 37 and 44, has a voltage drop of up to 95.03% to 95.31% with an average drop voltage of 95.1%, which means the average voltage drop. each feeder is ableto send electricity to consumers properly.

Calculation Method of Unbalanced Line Loss in Low-Voltage Distribution Network Considering the Access Mode of Distributed Photovoltaic Generation

Calculation Method of Unbalanced Line Loss in Low-Voltage Distribution Network Considering the Access Mode of Distributed Photovoltaic Generation

Losses in water distribution networks – a bibliometric review: general aspects and optimization

The research carried out in the water distribution networks is of great importance, given the social, environmental and economic impacts that have occurred due to the scarcity of water resources. Therefore, any scientific effort shown in research that studies water distribution systems is of great relevance. Techniques such as mathematical modeling, computer simulation and statistical methods are widely used in order to obtain more reliable answers, whether for the identification of the current situation of the network, as well as for the prediction of scenarios, failure events, increased demand, etc. The objective of this work is to carry out a bibliometric analysis to identify the state of the art of research that addresses the theme of water distribution networks for the control and reduction of the volume of water losses, which will serve as a guide for future works to to structure itself in the most relevant researches that study the theme. The developed methodology was able to analyze a metadata composed of 4188 documents taken from the Web of Science journals database. As a result, a geographical view of the theme was obtained, pointing out the main countries, affiliations, journals and researchers, as well as pointing out the main documents and relevance of the theme. It can be concluded after the results obtained that bibliometric analysis is an important tool for obtaining the state of the art. With it is possible to have a better understanding of the current situation in the development of research, familiarizing researchers with what is most current and relevant.

Appraising the Impact of Pressure Control on Leakage Flow in Water Distribution Networks

Water losses in Water Distribution Networks (WDNs) are inevitable. This is due to joints interconnections, ageing infrastructure and excessive pressure at lower demand. Pressure control has been showing promising results as a means of minimising water loss. Furthermore, it has been shown that pressure information at critical nodes is often adequate to ensure effective control in the system. In this work, a greedy algorithm for the identification of critical nodes is presented. An emulator for the WDN solution is put forward and used to simulate the dynamics of the WDN. A model-free control scheme based on reinforcement learning is used to interact with the proposed emulator to determine optimal pressure reducing valve settings based on the pressure information from the critical node. Results show that flows through the pipes and nodal pressure heads can be reduced using this scheme. The reduction in flows and nodal pressure leads to reduced leakage flows from the system. Moreover, the control scheme used in this work relies on the current operation of the system, unlike traditional machine learning methods that require prior knowledge about the system.

IMPROVING THE METHOD OF DETERMINING THE VALUE OF WATER LEVELS IN VERTICAL WELLS OF GROUP WATER COLLECTION

Purpose. Reconstruction of water supply systems to meet the increased water needs of consumers is a complex, time-consuming and expensive task. Reconstruction options include expanding existing water intakes or building new ones anywhere in the existing water supply network. The variety of options is accompanied by changes in water consumption in the sections of the networks and, importantly, in the flow distribution. The introduction of additional sources into the existing water supply systems requires a detailed study of the factors affecting the technical characteristics of the systems and responsible for the economic component of the project. Methodology. The influence of the determining factors on the total head losses in the water distribution network during the reconstruction of the water supply system is analyzed. An algorithm for finding the optimal network points for connecting an additional power source is proposed, which includes determining the optimal flow distribution and the corresponding technical changes for each selected option; total capacity of pumping stations and heads; analysis of the complete set of the water supply system of the accepted options; an economic analysis of the construction investment and operating costs that will accompany the operation of the water supply system design options. Findings. The choice of the optimal connection points for additional power sources depends on the amount of water flow in the network sections and the flow distribution. It is shown that the nodes of the end sections of the network most correspond to the conditions for searching for optimal points and can be fed from different directions, depending on the amount of additional flow. With an additional water flow rate no more than two nodal flow rates, the total head losses in the network sections are minimal. When an additional flow rate of more than two nodal flows enters the final node, an increase in head losses is observed, which can have critical values depending on its increase. The introduction of additional water flows into the network, which exceed two nodal ones, requires the use of intermediate network nodes located at sections with a higher throughput as connection points. Originality. The analysis of the factors influencing the choice of points of connection of additional power sources of the water supply network during its expansion is carried out. The analysis of the points was carried out with limited ranges of the values of water consumption of additional feeding − less and equal to the nodal ones, two and three times larger than the nodal ones. The ways of finding the optimal option for choosing a network node as a point of connection of additional power are shown. Practical value. The use of the analysis results will make it possible to most effectively search for the optimal variant of reconstruction of water supply systems, take into account the influence of determining factors on the characteristics of networks with changes in water consumption and flow distribution. The use of the analysis results will make it possible to most effectively search for the optimal variant of reconstruction of water supply systems, take into account the influence of determining factors on the characteristics of networks with changes in water consumption and flow distribution.

Optimal allocation of DSTATCOM and PV array in distribution system employing fuzzy-lightning search algorithm

Increased electric energy demand is the major factor that cracks the researchers to focus on electrical energy demand to meet the challenge. Accordingly, the power loss should be minimized. Due to this, Distribution Flexible Alternating Current Transmission System (DFACTS) and Distributed Generation (DG) must be placed in an appropriate way in distribution systems. Fuzzy-Lightning Search Algorithm (FLSA) has been proposed to minimize the power loss in the radial distribution network by solving the optimal placement problem of Distribution STATic COMpensator (DSTATCOM) as DFACTS device and photo voltaic (PV) array unit as DG. The improved voltage profile values, less power loss and reduced stability problems have been attained by using FLSA. The proposed FLSA technique is evaluated through IEEE 30-bus system with MATLAB software. The power flow investigation has been done by Newton Raphson method. Optimum siting of DSTATCOM and PV array induced outstandingly decreased the losses to 7.0073 kW. The accomplished objectives and results have validated the FLSA is more advantageous than other optimization techniques.

Detection of Non-Technical Losses in Electric Distribution Network by Applying Machine Learning and Feature Engineering

Non-technical losses (NTL), which occur up to 40% of the total electric transmission and distribution power, create many challenges worldwide. These losses have a severe impact on distribution utilities and adversely affect the performance of electrical distribution networks. Furthermore, the depreciation of these NTL reduces the requirement of new power plants to fulfill the demand-supply gap. Hence, NTL is an emerging research area for electrical engineers. This paper proposed a model for the detection of non-technical losses based on machine learning and feature engineering. Experimental results check the performance of the proposed model. These results clearly show that this proposed detection model has better accuracy, precision, recall, F1 score, and AUC score than other existing approaches.

A two-stage approach to enhance distribution network resilience against natural disasters

The natural disasters such as floods and storms have always led to widespread damage and seriously disrupt at the power distribution network. This paper, after presenting a new index to quantitatively calculate the resilience of the distribution network, proposes a two-stage approach to enhance distribution network resilience against natural disasters in the presence of distributed generation (DG) including photovoltaic and conventional gas-fired power sources. The first stage includes determining the boundaries of isolated zones and optimal capacity of the DG units in each zone with the aim of improving the resilience by considering budget constraint. The second stage includes determining the optimal location of DG in each zone with the aim of optimizing the distribution network losses. A genetic algorithm (GA) based optimization method is developed to solve the proposed problem. The performance of the proposed approach is assessed and illustrated by numerical studies on a practical distribution system from Iran.