Florina Scarlatache

Gheorghe Asachi Technical University of Iasi | TU Iasi · Department of Energy

The paper proposes a methodology to assess the impact of the increase in the number of prosumers in the low-voltage electrical distribution networks from the point of view of energy losses and voltage levels. A real low-voltage electrical distribution network belonging to a Romanian Distribution Network Operator has been used to demonstrate the eff...

The future distribution networks must ensure smart features like flexibility, accessibility, reliability, and high-power quality for all consumers. If the first three features can be satisfied by the Distribution Network Operators (DNOs) until a certain level depending on the investments, the power quality in each node and consumption point is not...

The future active distribution networks (ADNs) must ensure “smart” features like flexibility, accessibility, reliability, and high power quality for all consumers. Increased adoption of small-scale distributed energy sources (SSDES) helps decarbonise ADNs. In the present context, society must ensure the comprehensibility of the benefits stemming fr...

Digital Twin technology can potentially improve the security, control and resilience of the microgrids, considering a virtual model representation of each part integrated into an electrical power system. Using modern computing infrastructure based on faster real-time simulation, digital twins can allow a new approach to designing, operating and con...

A scenario-based optimization framework associated with voltage control in the electric networks with wind farms connected has been proposed in the paper. The optimization process corresponds to the Optimal Power Flow (OPF) problem, where the reduced gradient method, characterized by a fast convergence (few iterations), has been used. The proposed...

A modernization strategy associated with the replacement of the No-Load Tap Changer-fitted distribution transformers having low-performance standards (the commissioning year being before 2000) with the On-Load Tap Changer-fitted Tier 2 transformers according to the Eco-design European Directive, to ensure the flexibility of the voltage control in t...

The power quality indicators play a significant role in the characterization of the technical-economic performances of the electric distribution networks (EDNs), influencing the energy efficiency of the activities carried out at the end-user level. From the point of view of a decision-making process, it is difficult for the Distribution Network Ope...

The real-time control of optimal power flow (OPF) in electric networks represents, in the last period, a challenge for the Distribution Network Operators (DNOs) and Transmission System Operators (TSOs) under the conditions of large-scale integration of renewable energy sources. The paper focused on the voltage management in the electric networks wi...

Currently, all major Vehicle Manufacturers agree that the future of mobility is electric. All of them have started selling Electric Vehicles (EVs). It is clear that these types of vehicles will require charging, which in turn will have an impact over the power distribution systems. All the studies show that the impact over the power systems will be...

Innovative practices in irrigation systems can bring improvements in terms of economic efficiency and, at the same time, can reduce environmental impacts. Investment in high-tech technologies frequently involves additional costs, but an efficient water management system can increase the lifetime of the equipment. The most utilized electronic device...

In the paper, a coordinated control methodology of single-phase (1-P) end-users switching operations on the phases of an active electric distribution network (AEDN) has been proposed to obtain a minimum unbalance degree at the coupling common point (CCP) level with the main distribution system. The phase load balancing (PLB) process considers the s...

Innovative practices in irrigation systems can bring improvements in terms of economic efficiency and in the same time can reduce environmental impact. Investment in high tech technologies frequently involves additional costs, but an efficient water management can increase the lifetime of the equipment. The main objective of this article is to redu...

In the paper, a two-stage methodology has been proposed for the real-time load estimation in the electric distribution substations (EDSs) from the electric distribution networks (EDNs) using the data provided by pilot EDSs selected to be integrated into the SCADA system considering a clustering-based correlation criterion and multiple linear regres...

The paper presents the authors scientific research that determines the coexistence operation of the urban buildings closest to high voltage (HV) power lines. The coexisting study is a professional documentation for which the electrical and mechanical hypothesis of the overhead power lines are defined based on investigations, computation, observatio...

The impact of the prosumers on the replacement strategies of the transformers from the electric distribution networks imposed by the Eco-design Directive of the European Commission is studied in the paper. Thus, an original decision-making methodology, integrating two stages, is proposed considering various penetration degrees of the prosumers. In...

The global climate change mitigation efforts have increased the efforts of national governments to incentivize local households in adopting PV panels for local electricity generation. Since PV generation is available during the daytime, at off-peak hours, the optimal management of such installations often considers local storage that can defer the...

In the paper, a coordinated control methodology of single-phase (1-P) end-users switching oper-ations on the phases of an active electric distribution network (AEDN) has been proposed to ob-tain a minimum unbalance degree at the coupling common point (CCP) level with the main dis-tribution system. The phase load balancing (PLB) process considers th...

The global climate change mitigation efforts have increased the efforts of national government to incentivize local households in adopting individual renewable energy as a mean to help reduce the usage of electricity generated using fossil fuels and to gain independence from the grid. Since the majority of residential generation is made by PV panel...

The hydropower sector has gained more importance in the last decade since renewable resources have recorded a worldwide investment boom. Based on its advantages referring to the timely response at peak energy demand with excellent flexibility, hydropower plants must operate as efficiently as possible to cover the energy variations produced by the r...

In the paper, a clustering-based practical methodology to obtain the typically injected power profiles (TIPPs), which to help the DNOs in understanding the PV prosumers’ behaviour connected to the own networks, was proposed. The installed capacity and annual energy have been considered in the classification process using the K-means clustering algo...

The key challenge of smart cities is the need to satisfy the conditions for a safe distance between the buildings, streets, or green areas (public gardens) and the classical high voltage overhead line. If the interference effects are high enough, they may pose a safety hazard to personnel or the public or may compromise their integrity. This paper...

To benefit from all advantages of a hydropower plant, seen as a renewable source, reliable and low cost of the injected electricity in the power grids, the Hydro Plant Operator (HPO) must ensure the optimal operating regimes and an efficient maintenance program. In this context, a clustering- based methodology has been proposed in the paper to dete...

In the paper, a Data Mining methodology is proposed to identify the energy features of the prosumers. The K-means clustering algorithm has been used to obtain prosumers’ categories considering two specific indicators which can help the Distribution Network Operators (DNOs) in the optimal operating of the networks, namely the injected average hourly...

In the last years, the distribution network operators (DNOs) assumed transition strategies of the electric distribution networks (EDNs) towards the active areas of the microgrids where, regardless of the operating regimes, flexibility, economic efficiency, low power losses, and high power quality are ensured. Artificial intelligence techniques, com...

In the last years, the Distribution Grid Operators (DGOs) assumed transition strategies of the distribution grids towards an active area associated with the "Smart Grids" concept. They are considering the use of Artificial Intelligence techniques, combined with advanced technologies and real-time remote communication solutions of the enormous data...

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A decision making methodology to explore the optimal planning strategy on a hybrid energy system from a micro-grid is presented considering the advantages and the importance of operation in stand-alone of these systems.

The book presents the most important professional and scientific activities of the authors in the operation and planning of electric distribution systems from the last 10 years. These research directions were motivated by the current technological developments in the power engineering field and the gradual implementation of smart grids. At present,...

The platform has a module that is provided for administering data bases relating to location and architectural construction characteristics of buildings and enclosures, and to technical-economical characteristics of electric installations components, including electric power production and storage, compulsory requirements/conditions as set out in s...

An analysis on the influence of sampling size used in the profiling process of electricity consumption at Small and Medium Enterprise (SMEs) is presented in this paper. The sampling size is very important because if the production processes inside SMEs have a dynamic change, with more equipment which come in and out of service very fast (seconds or...

The software platform comprises four modules. A first module is adapted for managing databases corresponding to electric energy and natural gas consumption. A second module is adapted for consumption and costs analysis which permits a user to obtain information such as the statistical analysis of consumption over a requested time interval depending...

The paper presents the results of a new statistical based data mining approach that explores the load curves in order to detect abnormal data, the so-called outliers. The load curves characterized by their main indicators are provided from Smart Meters mounted on the power substation. The proposed method was tested using a real database with 290 su...

The voltage control represents one of the most important qualitative factors, and it is addressed to the secondary power system control level. The performance of secondary voltage control depends strongly on the selection of pilot nodes. This paper proposes the use of K-means clustering algorithm order to the identification of pilot nodes for Secon...

This chapter is focused on the DG sources integration, in particular, on the planning and optimal operation of the electrical distribution systems with significant DG sources connected. It assesses the impact of the DG sources regarding the energy losses and voltage magnitude, in context of the optimal location and sizing of the DG sources into an...

The paper proposes a heuristic approach to resolve the phase balancing problem in LV distribution networks. The approach is based upon the recordings of electricity of the consumers (endowed with smart meters) for a week-long study period. The results obtained for a real LV distribution feeder that serves a rural area using the information provided...

The paper presents a statistical approach used for detection of outliers from load curves recorded on the electric substation of distribution networks. The load curves provided by smart meters were processed and their main indicators were calculated. By outliers elimination, the remaining data have led to the discovery of accurate patterns that cha...

The paper presents a comprehensive approach using clustering based data mining for load curves characterization in real distribution networks. The load curves characterized by their main indicators is made using information provided by Smart Meters. The proposed method was tested using a real database with 60 rural substations. The results demonstr...

The paper aims to realize the micro-grid control in presence of distributed generation (DG) sources and the automatic voltage regulators (AVR). The provided analysis had into account highlighting the influence of the hybrid energy systems with consideration of the automatic voltage regulators on the power losses and the voltage level into micro-gri...

The analysis of data represents the starting point for many applications in the power systems, either in the design phase, either in operation for on-line control. The need to extend the capabilities of human analysis for to handle the overwhelming quantity of data that we are able to collect has become vital. The ability of human operators to manu...

The paper proposes a fuzzy approach for the optimal distributed generation (DG) sources planning in the electrical distribution systems. This approach aims to determine the optimal nodes where DG sources can be connected and also the optimal degree of penetration of these sources. Through a proper installation of DG sources in distribution networks...

Today, the electricity distribution networks supply a significant number of nonlinear consumers which causes a distorted and unbalanced state. A negative effect of these states is represented by the increase of power losses in the network elements. Even if the symmetrical sinusoidal state is initially considered for the power losses, in reality thi...

The paper presents a fuzzy approach for evaluation of the power/energy losses in transformers from the electrical distribution networks considering three input variables: the loading factor, the voltage on low side, and the performance standard. These are modelled as linguistic variables and fuzzy numbers. The obtained results on a real distributio...

This paper presents a decision making methodology based on fuzzy logic for an optimal location of distributed generation (DG) sources into an electrical distribution system to reduce the losses and improve the voltage profile. The methodology has two stages: at first is determined the preferential zone where can be located the DG based on the opera...

The paper investigates the power losses for real distribution networks in harmonic polluted state. Actually, the low voltage (LV) distribution networks supply a significant number of nonlinear consumers which causes a distorted and unbalanced state. A negative effect of these states is represented by the increase of power losses in distribution net...

This paper proposes a decision making methodology using clustering methods and fuzzy techniques to determine the optimal location of distributed generation sources into an electrical distribution system. Based on the operational characteristics (loss sensitivity factor and voltage values in nodes) first of all was found the optimal distribution net...

The paper presents a Mining Data based approach for peak load estimation of household consumers. The approach uses an unsupervised learning method (clustering) along with the polynomial regression. With K-means clustering algorithm, the consumption categories of household consumers were determined. The input data for the consumers’ classification i...

This paper presents an assessment of the renewable energy potential in Romania using a clustering based data mining method. The available data on installed capacity, level voltage, type of renewable technology and geographical location the renewable energy potential for electricity generation was mapped into representative zones using K-Means clust...

The behavior of an electric customer can be identified through a load profile corresponding to a certain period of time. Information can be available depending on type of customer and customer classification is based only the billing data. But, there are many countries where the Smart Metering Systems are becoming more common and the customer class...

In recent years, renewable energy sources (RES) has increased all over the world, especially in Europe, and the changes brought by these sources have a significant impact on system performance and efficiency. Integrating RES to an electric power network offers many techno-economical benefits and in the same time necessitate advances in the operatio...

The paper is focused on slow voltage variations in the nodes of an electric distribution system. A clustering based approach to classify the nodes (substations) in categories described by linguistic terms from viewpoint of slow voltage variations is proposed. The linguistic terms are defined in function by the daily average load of nodes and the vo...

The basic function of a power system is to provide an adequate electrical supply to its customers as economically as possible with reasonable level of reliability. Evaluating the reliability of a power system is a complex process and the work with the actual methods is difficult. Reliability studies require information about the history of the netw...

Due to the growing integration of distributed generation sources (DG) into electrical power systems, it is important to acquire knowledge concerning their operation characteristics. An important aspect is the volatility nature of these sources, especially wind sources. Thus, it is necessary that the electrical system in which this type of DG source...

The paper presents a clustering based algorithm for consumers' classification in representative consumption categories characterized by typical load profiles obtained using measurements performed by smart meters. The results obtained were extended to other consumers that don't have a smart metering system implemented. In the case study, a working d...

Estimation of the power/energy losses constitutes an important tool for an efficient planning and operation of electric distribution systems, especially in a free energy market environment. For further development of plans of energy loss reduction and for determination of the implementation priorities of different measures and investment projects,...

The paper focuses on the development of a method based on representative load profiles of the hydrophore stations, in order to electrical energy consumption estimation in the water distribution system. The proposed method is based on two stages in which K-means clustering algorithm and a load simulation technique are exploited for estimating the el...

The estimation of the power/energy losses represents an important tool for efficient planning and operation of power systems, especially in a free energy market environment. This paper proposes the use of a new method based on decision trees to estimate the power/energy losses in the electric distribution systems. A comparative study was realized u...

The objective of this paper is to obtain the solution for minimized network power losses by optimally locating the distributed generation (DG) sources taking into consideration the total injection power of DG installed into a electrical distribution network. The method proposed in this paper is tested on a 20 kV electrical distribution network. The...

The paper presents a comparative study regarding the optimal placement of distributed generation (DG) sources into a electrical distribution system using an algorithm with two stages: in the first stage a clustering-based method is used to find the optimal partitioning of the network nodes into clusters, and in the second stage the optimal size of...

Nowadays, distributed generation (DG) is playing a significant role in the electrical energy systems. The diffusion of DG in the electrical networks could be beneficial to improve network operation, but excessive amounts of DG in operation could cause violations of the system constraints. This paper presents a new method to obtain the optimal size...

In electrical distribution systems, except the usual measurements from stations, there are few information about the state of network. As a result, there is at any moment a generalized uncertainty about the power demand conditions and therefore about the network loading, voltage level, power losses, etc. Therefore, it is important to establish accu...

This paper proposes a method using k-means clustering, based on the operational characteristics (loss sensitivity factor and voltage values in nodes) to determine the optimal location of distributed generation sources into an electrical distribution system. The suggested method is tested on a 20 kV real rural distribution network with 91 nodes. In...

The reduction of energy losses in distribution networks represents an important issue during planning and operation with important technical and economical implications. Level of energy losses depends upon a number of parameters and variables, such as the nominal circuit voltage, the installed transformer capacity, the number of transformation poin...

The replacement of the old transformers with efficient transformers provide an excellent opportunity to conserve energy right from the distribution installations and to recover the cost of equipment rendered obsolete by deployment of the Smart Grid System. The size and complexity of distribution networks make it impossible to carry out an exhaustiv...

The operational strategy for maintain system stability is based on technological system services bidden by the OTS from the market. The modality from which the producers evaluated themselves the reserve of power takes an important role. Analyzing load profile from the hydro cascade is the first step that electrical companies must do for evaluated t...