scholarly journals Utilization of Active Distribution Network Elements for Optimization of a Distribution Network Operation

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3494
Author(s):  
Nevena Srećković ◽  
Miran Rošer ◽  
Gorazd Štumberger

Electricity Distributions Networks (DNs) are changing from a once passive to an active electric power system element. This change, driven by several European Commission Directives and Regulations in the energy sector prompts the proliferated integration of new network elements, which can actively participate in network operations if adequately utilized. This paper addresses the possibility of using these active DN elements for optimization of a time-discrete network operation in terms of minimization of power losses while ensuring other operational constraints (i.e., voltage profiles and line currents). The active elements considered within the proposed optimization procedure are distributed generation units, capable of reactive power provision; remotely controlled switches for changing the network configuration; and an on-load tap changer-equipped substation, supplying the network. The proposed procedure was tested on a model of an actual medium voltage DN. The results showed that simultaneous consideration of these active elements could reduce power losses at a considered point of operation while keeping the voltage profiles within the permitted interval. Furthermore, by performing a series of consecutive optimization procedures at a given time interval, an optimization of network operations for extended periods (e.g., days, months, or years) could also be achieved.

2018 ◽  
Vol 69 (1) ◽  
pp. 85-92 ◽  
Author(s):  
Ghaeth Fandi ◽  
Famous Omar Igbinovia ◽  
Josef Tlusty ◽  
Rateb Mahmoud

Abstract A medium-voltage (MV) wind production system is proposed in this paper. The system applies a medium-voltage permanent magnet synchronous generator (PMSG) as well as MV interconnection and distribution networks. The simulation scheme of an existing commercial electric-power system (Case A) and a proposed wind farm with a gearless PMSG insulated gate bipolar transistor (IGBT) power electronics converter scheme (Case B) is compared. The analyses carried out in MATLAB/Simulink environment shows an enhanced voltage profile and reduced power losses, thus, efficiency in installed IGBT power electronics devices in the wind farm. The resulting wind energy transformation scheme is a simple and controllable medium voltage application since it is not restrained by the IGBT power electronics voltage source converter (VSC) arrangement. Active and reactive power control is made possible with the aid of the gearless PMSG IGBT power converters.


2021 ◽  
Vol 3 (5) ◽  
Author(s):  
Arvind Sharma ◽  
Mohan Kolhe ◽  
Alkistis Kontou ◽  
Dimitrios Lagos ◽  
Panos Kotsampopoulos

Abstract In this paper, solar photovoltaic hosting capacity within the electrical distribution network is estimated for different buses, and the impacts of high PV penetration are evaluated using power hardware-in-loop testing methods. It is observed that the considered operational constraints (i.e. voltage and loadings) and their operational limits have a significant impact on the hosting capacity results. However, with increasing photovoltaic penetration, some of the network buses reach maximum hosting capacity, which affects the network operation (e.g. bus voltages, line loading). The results show that even distributing the maximum hosting capacity among different buses can increase the bus voltage rise to 9%. To maintain the network bus voltages within acceptable limits, reactive power voltage-based droop control is implemented in the photovoltaic conditioning devices to test the dynamics of the network operation. The results show that implementation of the droop control technique can reduce the maximum voltage rise from 9% to 4% in the considered case. This paper also presents the impact of forming a mesh type network (i.e. from radial network) on the voltage profile during PV penetration, and a comparative analysis of the operational performance of a mesh type and radial type electrical network is performed. It is observed that the cumulative effect of forming a mesh type network along with a droop control strategy can further improve the voltage profile and contribute to increase photovoltaic penetration. The results are verified using an experimental setup of digital real-time simulator and power hardware-in-loop test methods. The results from this work will be useful for estimating the appropriate photovoltaic hosting capacity within a distribution network and implementation of a droop control strategy in power conditioning devices to maintain the network operational parameters within the specified limits. Highlights Voltage and line loading constraints’ combination can reduce PV hosting capacity by 50% as compared to only voltage as a constraint. Implementation of reactive power versus voltage droop control in PV power conditioning device can reduce voltage variation from 9% to 4%. In a PV integrated electrical energy network, line loading can be reduced by 20% if the network is configured from radial to mesh type.


Vestnik MEI ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 11-18
Author(s):  
Nailia Sh. Chemborisova ◽  
◽  
Ivan D. Chernenkov ◽  

The problem of selecting the electric power system control nodes is studied. By performing control of these modes, matters concerned with providing reliable power supply of the required quality to consumers can be settled in the most efficient manner. As an example, a fragment of the electric power system mathematical model used in the Finist mode-setting simulator for a power system dispatch control center operator is considered, which represents a highly branched electrical network consisting of eleven 110 kV nodes, three 220 kV nodes connected with the system, and two generator nodes. A new procedure for selecting the control nodes is proposed, which takes into account a combination of different indicators having different measurement units, dimensions and scales is proposed. These indicators characterize the following properties of power system nodes: the reactive power fraction absorbed at a node, the sensitivity of voltage to reactive load variations, the number of connected power lines, and statistical indicators characterizing the change of voltage at the nodes and reactive power flows for different options of installing the reactive power compensation devices. For combined use of these indicators, they were ranked according to the efficiency of installing reactive power compensation devices in the system. For each indicator, a scale of five ranks (intervals) is set, which determine the preferences (qualitative judgments) of the researcher in evaluating the reactive power compensation devices installation efficiency at the system nodes. The highest rank (5) corresponds to the maximum efficiency, and the lowest rank (1) corresponds to the minimum efficiency. To calculate the individual (integral) priority indicator of installing reactive power compensation devices, the ranks of indicators are added together, and their sum is divided by the product of the number of ranks by the number of the used indicators (features). Based on the calculation results, the rating (location) of each node is determined, and the nodes for installing the reactive power compensation devices are selected according to their effect on ensuring the electric power system operation reliability, active power losses in the network, and voltage regulation. Thus, a new procedure is presented for determining the integral indicators for comprehensively estimating the properties of complex electric power system nodes and selecting the controlled nodes using a system of various indicators. These indicators characterize the studied nodes in terms of the efficiency of installing reactive power compensation devices to reduce active power losses in the network, voltage regulation, and ensuring the electric power system operational reliability. The validity of the results obtained in the study is confirmed by their comparison with the indicators of the balance-conductivity method, which has proven itself in solving problems connected with determining the nodes for controlling electric power system operation modes.


2016 ◽  
Vol 12 (1) ◽  
pp. 71-78
Author(s):  
Hamza Yapıcı ◽  
Nurettin Çetinkaya

In this paper the minimization of power losses in a real distribution network have been described by solving reactive power optimization problem. The optimization has been performed and tested on Konya Eregli Distribution Network in Turkey, a section of Turkish electric distribution network managed by MEDAŞ (Meram Electricity Distribution Corporation). The network contains about 9 feeders, 1323 buses (including 0.4 kV, 15.8 kV and 31.5 kV buses) and 1311 transformers. This paper prefers a new Chaotic Firefly Algorithm (CFA) and Particle Swarm Optimization (PSO) for the power loss minimization in a real distribution network. The reactive power optimization problem is concluded with minimum active power losses by the optimal value of reactive power. The formulation contains detailed constraints including voltage limits and capacitor boundary. The simulation has been carried out with real data and results have been compared with Simulated Annealing (SA), standard Genetic Algorithm (SGA) and standard Firefly Algorithm (FA). The proposed method has been found the better results than the other algorithms.


2020 ◽  
Vol 64 (2) ◽  
pp. 157-169
Author(s):  
Benalia M'hamdi ◽  
Madjid Teguar ◽  
Benaissa Tahar

The optimal allocation and size of decentralized generating units are essential to minimize power losses, while meeting the demand for active and reactive power in a distribution system. In other words, most of the total energy produced can be efficiently exploited by end users. In addition, if the DGs are of optimal size and location in the distribution system, the reliability, stability and efficiency of the power system are guaranteed. This paper focuses on reducing power losses and improving the voltage profile by accurately identifying the optimal location and sizing of Distributed Generation based on three indexes, namely the IVM Index Vector Method, the VDI Voltage Deviation Index and the VSI Voltage Stability Index. Two types of DGs were considered for the analysis: DGs operating with unit power factor and DGs operating with a lagging power factor. Three optimization algorithms are applied to determine the optimal sizes of decentralized generation units in a power distribution network which are GWO, WOA and PSO. The results obtained in this article show that the three algorithms give very similar values. DG at lagging power factor gives better results compared with those obtained with DGs at unity power factor. In terms of loss reduction and minimum bus voltage, the best results are obtained for the VSI index with a DG at a power factor of 0.9.


Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 972 ◽  
Author(s):  
Fermín Barrero-González ◽  
Victor Pires ◽  
José Sousa ◽  
João Martins ◽  
María Milanés-Montero ◽  
...  

The proliferation of residential photovoltaic (PV) prosumers leads to detrimental impacts on the low-voltage (LV) distribution network operation such as reverse power flow, voltage fluctuations and voltage imbalances. This is due to the fact that the strategies for the PV inverters are usually designed to obtain the maximum energy from the panels. The most recent approach to these issues involves new inverter-based solutions. This paper proposes a novel comprehensive control strategy for the power electronic converters associated with PV installations to improve the operational performance of a four-wire LV distribution network. The objectives are to try to balance the currents demanded by consumers and to compensate the reactive power demanded by them at the expense of the remaining converters’ capacity. The strategy is implemented in each consumer installation, constituting a decentralized or distributed control and allowing its practical implementation based on local measurements. The algorithms were tested, in a yearly simulation horizon, on a typical Portuguese LV network to verify the impact of the high integration of the renewable energy sources in the network and the effectiveness and applicability of the proposed approach.


2019 ◽  
Vol 9 (6) ◽  
pp. 1129 ◽  
Author(s):  
Lingling Wang ◽  
Xu Wang ◽  
Chuanwen Jiang ◽  
Shuo Yin ◽  
Meng Yang

This paper proposes a coordinated active–reactive power optimization model for an active distribution network with energy storage systems, where the active and reactive resources are handled simultaneously. The model aims to minimize the power losses, the operation cost, and the voltage deviation of the distribution network. In particular, the reactive power capabilities of distributed generators and energy storage systems are fully utilized to minimize power losses and improve voltage profiles. The uncertainties pertaining to the forecasted values of renewable energy sources are modelled by scenario-based stochastic programming. The second-order cone programming relaxation method is used to deal with the nonlinear power flow constraints and transform the original mixed integer nonlinear programming problem into a tractable mixed integer second-order cone programming model, thus the difficulty of problem solving is significantly reduced. The 33-bus and 69-bus distribution networks are used to demonstrate the effectiveness of the proposed approach. Simulation results show that the proposed coordinated optimization approach helps improve the economic operation for active distribution network while improving the system security significantly.


Author(s):  
Ivan Nadtoka ◽  
◽  
Pyotr Osadchiy ◽  
Vladimir Tropin ◽  
◽  
...  

The features of applying the «open triangle» scheme in the structure of a rural low-voltage distribution network with a voltage of 220 V are studied from the standpoint of achieving a certain energy efficiency. The energy effect is estimated by the criterion of the relative value of the additional power losses in the conductors of a three-wire line of a 220 V network caused by reactive power and load asymmetry. The load is modeled by two power receivers connected to the phase-to-phase voltage, the general output of the power receivers is grounded, which forms the «open triangle» circuit. The energy characteristics of the active load, active load with capacitive corrective element, active load with capacitive and inductive corrective elements are analyzed; and also the most practical case – active-inductive load with various values of reactive power factors -0,1; 0,2; 0,3 and capacitive corrective element. An important feature of applying the «open triangle» scheme in the structure of a rural low-voltage distribution network with a voltage of 220 V, from the standpoint of achieving practically necessary and sufficient energy efficiency - not exceeding 10 % of the additional power losses, is the ability to compensate for reactive power and balancing the phase currents of the network line using only one corrective capacitor of relatively low power - about 50 % of the active power of one power receiver.


2020 ◽  
Vol 4 (3) ◽  
pp. 34-40
Author(s):  
Ahmad Jaya ◽  
Wirentake

This study aims to determine the loss / power loss in the nijang feeder through the energy reconciliation process, simulation of the ETAP 12.6 program, and manual calculations. The benefits of this research can be used as a basis for consideration of the improvement efforts that should be carried out to minimize power losses in the medium voltage distribution network of Nijang feeders. The method used is quantitative research method because it takes data from the measurement of the transaction point which is then compared with the results in the simulation program ETAP 12.6 and manual calculations. The results showed that the power loss (kWh) resulted from 3 processes showed that the energy reconciliation process resulted in a greater power loss, namely 10,657 kWh, the ETAP 12.6 simulation resulted in a power loss of 3049 kWh and in manual calculations it resulted in losses. power of 4199 kWh, from the results of the research it can be seen that in the simulation process ETAP 12.6 and manual calculations only calculate power losses due to technical causes, while the energy reconciliation process includes technical and non-technical causes. It is hoped that this research can support efforts to improve power losses / losses in the PT PLN (Persero) UP3 Sumbawa environment.


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