scholarly journals Supply Restoration in Active Distribution Networks Based on Soft Open Points with Embedded DC Microgrids

Mathematics ◽  
2022 ◽  
Vol 10 (2) ◽  
pp. 211
Author(s):  
Irina I. Picioroaga ◽  
Andrei M. Tudose ◽  
Dorian O. Sidea ◽  
Constantin Bulac

As disturbances due to natural disasters or man-made attacks intensify awareness regarding power systems’ resilience enhancement, the scientific community concentrates on exploring state-of-the-art technologies for emergency supply restoration strategies. Recent studies are increasingly focusing on the expanded flexibility of soft open points (SOPs) compared to conventional tie-switches to increase the restoration rate of critical loads; however, the potential of this novel technology is not limited to this aspect, with SOPs being used to improve the voltage level and increase the hosting capacity of renewable energy sources (RESs). This paper proposes a deterministic model for the optimal coordination of SOPs and distributed resources in an active distribution network (ADN) aiming at re-establishing the energy supply to critical loads after a prolonged interruption occurrence. At the same time, the support of DC microgrids with integrated RESs, embedded in SOPs, for the restoration process is explored. The efficiency of the proposed optimization model is verified based on a 24-h analysis performed on the modified IEEE 33-bus system, while considering the load and generation uncertainties as well.

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
A. Elsherif ◽  
T. Fetouh ◽  
H. Shaaban

In recent years a multitude of events have created a new environment for the electric power infrastructure. The presence of small-scale generation near load spots is becoming common especially with the advent of renewable energy sources such as wind power energy. This type of generation is known as distributed generation (DG). The expansion of the distributed generators- (DGs-) based wind energy raises constraints on the distribution networks operation and power quality issues: voltage sag, voltage swell, voltage interruption, harmonic contents, flickering, frequency deviation, unbalance, and so forth. Consequently, the public distribution network conception and connection studies evolve in order to keep the distribution system operating in optimal conditions. In this paper, a comprehensive power quality investigation of a distribution system with embedded wind turbines has been carried out. This investigation is carried out in a comparison aspect between the conventional synchronous generators, as DGs are widely in use at present, and the different wind turbines technologies, which represent the foresightedness of the DGs. The obtained results are discussed with the IEC 61400-21 standard for testing and assessing power quality characteristics of grid-connected wind energy and the IEEE 1547-2003 standard for interconnecting distributed resources with electric power systems.


Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1037 ◽  
Author(s):  
Arslan Bashir ◽  
Matti Lehtonen

Current energy policy-driven targets have led to increasing deployment of renewable energy sources in electrical grids. However, due to the limited flexibility of current power systems, the rapidly growing number of installations of renewable energy systems has resulted in rising levels of generation curtailments. This paper probes the benefits of simultaneously coordinating aggregated hydro-reservoir storage with residential demand response (DR) for mitigating both load and generation curtailments in highly renewable generation power systems. DR services are provided by electric water heaters, thermal storages, electric vehicles, and heating, ventilation and air-conditioning (HVAC) loads. Accordingly, an optimization model is presented to minimize the mismatch between demand and supply in the Finnish power system. The model considers proportions of base-load generation comprising nuclear, and combined heat and power (CHP) plants (both CHP-city and CHP-industry), as well as future penetration scenarios of solar and wind power that are constructed, reflecting the present generation structure in Finland. The findings show that DR coordinated with hydropower is an efficient curtailment mitigation tool given the uncertainty in renewable generation. A comprehensive sensitivity analysis is also carried out to depict how higher penetration can reduce carbon emissions from electricity co-generation in the near future.


Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3610
Author(s):  
Dawid Buła ◽  
Dariusz Grabowski ◽  
Andrzej Lange ◽  
Marcin Maciążek ◽  
Marian Pasko

Network working conditions are influenced noticeably by the connection of renewable energy sources to distribution networks. This becomes more and more important due to the increase in renewable energy source penetration over the last few years. This in turn can lead to a mass effect. As a result, the classical open network model with simple unidirectional direction of energy flow has been replaced with an active model that includes many local energy sources. This paper deals with the analysis of long- and short-term changes in power and energy generated by three types of renewable energy sources with similar rated power and which operate in the same region (i.e., located no more than tens of kilometers away). The obtained results can be a starting point for a broader evaluation of the influence of renewable energy sources on power quality in power systems, which can be both positive (supply reliability) and negative (voltage fluctuations and higher harmonics in current and voltage waveforms). It is important not only to correctly place but also to assure the diversity of such sources as it has been confirmed by the source variability coefficient. The long-term analysis allows us also to estimate the annual repeatability of energy production and, furthermore, the profitability of investment in renewable sources in a given region.


Electronics ◽  
2021 ◽  
Vol 10 (17) ◽  
pp. 2093
Author(s):  
Miguel Aybar-Mejía ◽  
Junior Villanueva ◽  
Deyslen Mariano-Hernández ◽  
Félix Santos ◽  
Angel Molina-Garcia

It is expected that distribution power systems will soon be able to connect a variety of microgrids from residential, commercial, and industrial users, and thus integrate a variety of  distributed generation technologies, mainly renewable energy sources to supply their demands. Indeed, some authors affirm that distribution networks will propose significant changes as a consequence of this massive integration of microgrids at the distribution level. Under this scenario, the control of distributed generation inverters, demand management systems, renewable resource forecasting, and demand predictions will allow better integration of such microgrid clusters to decongest power systems. This paper presents a review of  microgrids connected at distribution networks and the solutions that facilitate their integration into such distribution network level, such as demand management systems, renewable resource forecasting, and demand predictions. Recent contributions focused on the application of microgrids in Low-Voltage distribution networks are also analyzed and reviewed in detail. In addition, this paper provides a critical review of the most relevant challenges currently facing electrical distribution networks, with an explicit focus on the massive interconnection of electrical microgrids and the future with relevant renewable energy source integration.


Author(s):  
Heliasadat Hosseinian ◽  
Hossein Shahinzadeh ◽  
Gevork B. Gharehpetian ◽  
Zohreh Azani ◽  
Mahdi Shaneh

Nowadays, unlike depleting fossil fuel resources, the integration of different types of renewable energy, as distributed generation sources, into power systems is accelerated and the technological development in this area is evolving at a frantic pace. Thus, inappropriate use of them will be irrecoverably detrimental. The power industry will reach a turning point in the pervasiveness of these infinite energy sources by three factors. Climate changes due to greenhouse gas accumulation in the atmosphere; increased demand for energy consumption all over the world, especially after the genesis of Bitcoin and base cryptocurrencies; and establishing a comprehensive perspective for the future of renewable energy. The increase in the pervasiveness of renewable energy sources in small-scale brings up new challenges for the power system operators to manage an abundant number of small-scale generation sources, called microsources. The current structure of banking systems is unable to handle such massive and high-frequency transactions. Thus the incorporation of cryptocurrencies is inevitable. In addition, by utilization of IoT-enabled devices, a large body of data will be produced must be securely transferred, stored, processed, and managed in order to boost the observability, controllability, and the level of autonomy of the smart power systems. Then the appropriate controlling measures must be performed through control signals in order to serve the loads in a stable, uninterruptible, reliable, and secure way. The data acquires from IoT devices must be analyzed using artificial intelligence methods such as big data techniques, data mining, machine learning, etc. with a scant delay or almost real-time. These measures are the controversial issues of modern power systems, which are yet a matter of debate. This study delves into the aforementioned challenges and opportunities, and the corresponding solutions for the incorporation of IoT and blockchain in power systems, particularly in the distribution level and residential section, are addressed. In the last section, the role of IoT in smart buildings and smart homes, especially for energy hubs schemes and the management of residential electric vehicle supply equipment is concisely discussed.


Author(s):  
Yuri Bulatov ◽  
◽  
Andrey Kryukov ◽  
Aleksandr Cherepanov ◽  
◽  
...  

Decentralization of electricity generation based on distributed generation plants is an important segment of the new technology platform for the power industry. On the basis of this approach, significant positive effects can be obtained, which consist in reducing financial costs of energy supply, increasing the uninterrupted power supply, improving the quality of electricity and stimulating the use of renewable energy sources. Effective use of distributed generation in electric power systems requires the development of methods and tools that provide coordinated management of normal, emergency and post-emergency modes. Of particular relevance is the problem of determining the limit operating modes of networks, at the nodal points of which relatively low power generators are connected. In some situations, for example, when using small hydraulic stations, groups of such generators can be located at significant distances for 6-10-20 kV distribution networks from consumption centers. In this case there will be a noticeable limitation of the regions of static aperiodic stability. The article presents the results of developments aimed at implementing methods for determining the limit operating modes by static aperiodic stability in networks with distributed generation plants. The proposed approach is based on the limit modes equations which provide the formation of effective algorithms for the operational finding of points belonging to the boundaries of stability regions. The results of the construction of the indicated areas for a 6 kV electric network with distributed generation plants based on low-power hydraulic stations are presented. Additionally, the transient processes in the studied electric power system were simulated in the Matlab system for various space points of the controlled mode parameters.


Author(s):  
Isidro Fraga Hurtado ◽  
Julio Rafael Gómez Sarduy ◽  
Percy Rafael Viego Felipe ◽  
Vladimir Sousa Santos ◽  
Enrique Ciro Quispe Oqueña

Smart grids can be considered as a concept that integrates electrical, automatic control, information, and communication technologies. This concept constitutes a fundamental complement in the integration of renewable energy sources in electrical power systems. Although its application is fundamentally framed in transmission and distribution networks, it could also be implemented in industrial electrical systems. This article aims to analyze the advantages of implementing solutions based on smart grids in the industrial sector. Likewise, the results of its implementation in the large industry in the province of Cienfuegos, Cuba are presented. Specifically, reactive compensation, voltage, and demand management controls were integrated into a Supervision, Control, and Data Acquisition system forming a smart grid. It is shown that, in industries where infrastructure and equipment conditions exist, it is possible to successfully implement solutions with the functionalities and benefits inherent to smart grids.


Author(s):  
Marino Godoy Arcia ◽  
Zaid Garcia Sanchez ◽  
Hernan Hernandez Herrera ◽  
José Antonio Gonzalez Cueto Cruz ◽  
Jorge Iván Silva Ortega ◽  
...  

The renewable energy sources (RESs) projects are solutions with environmental benefits that are changing the traditional power system operation and concept. Transient stability analysis has opened new research trends to guarantee a secure operation high penetration. Problems such as frequency fluctuations, decoupling between generator angular speed, network frequency fluctuation and kinetic energy storing absence are the main non-conventional RESs penetration in power systems. This paper analyzes short-circuit influence on frequency response, focusing on weak distribution networks and isolated, to demonstrate relevance in frequency stability. A study case considered a generation outage and a load input to analyze frequency response. The paper compares frequency response during a generation outage with a short-circuit occurrence. In addition, modular value and angle generator terminal voltage affectation by electric arc and network ratio R⁄X, failure type influence in power delivered behavior, considering fault location, arc resistance and load. The arc resistance is defined as an added resistance that appears during failure and influences voltage modulus and angle value results showing that intermittent non-conventional RES participation can lead to frequency fluctuations. Results showed that arc resistance, type of failure, location and loadability determine the influence of frequency response factors in weak power systems.


2018 ◽  
pp. 117-125

Desarrollo de Convertidores Electrónicos Bidireccionales   de Potencia para Sistemas de Generación de Energías Renovables usando Control Predictivo Juan   F.  Tisza   C. Universidad Nacional de Ingeniería, Av. Túpac Amaru 210, Rímac, Lima, Perú Recibido el 4 de diciembre del 2018, Aceptado el 27 de diciembre de 2018 DOI: https://doi.org/10.33017/RevECIPeru2018.0018/ Resumen Este trabajo se desarrolla un convertidor electrónico bidireccional de potencia eléctrica AC/DC y se evalúan sus indicadores de rendimiento, todo este estudio en un contexto en el cual se busca incrementar la generación de fuentes de energía renovables en la matriz energética del Perú, en especial las fuentes solar y eólica. Actualmente es de particular  importancia la consolidación de la generación de energía eléctrica distribuida [1].En este escenario los  sistemas de  conversión bilateral  de  energías    DC  y AC [5] son de gran importancia ,Se  busca tener un comportamiento eficiente y con técnicas de control avanzadas  que permitan reducir las distorsiones de armónicos, así  como también tener  la robustez  ante perturbaciones y minimizar las  eventuales  inestabilidades  que se produzcan al  conectarse a las  redes públicas   de distribución eléctrica [2],(en forma cuantificada el objetivo  es tener menos  del 2% en THD, en la variable  de  interés). El desarrollo se realiza    mediante la aplicación del Control Predictivo Basado en Modelos en su versión de aplicación llamada tipo Conjunto Finito de Conmutaciones (“Finite Commutation Set” FCS), así las unidades de control de la etapa de potencia son implementadas con control   MPC-FCS. Se muestran los principales resultados obtenidos mediante herramientas de simulación (Matlab y PSIM) aplicados a estos sistemas electrónicos de potencia (Se establecen como objetivos de la investigación conseguir eficiencias eléctricas por encima del 98%). En este estudio se tiene muy en cuenta la medición de la magnitud y la dirección del flujo de potencia y energía eléctrica entre las fuentes de generación, la red, la carga y los almacenadores de energía. Se presentan los resultados más significativos que muestran los resultados y la metodología que en definitiva tiene un mejor comportamiento que los implementados con los métodos ampliamente usados como el SVPWM. Descriptores: Energías renovables, generación distribuida, convertidores electrónicos de Potencia, MPC-FCS, THD. Abstract This work develops a bidirectional electronic converter of AC/DC electric power and evaluates its performance indicators, all this study in a context in which it seeks to increase the generation of renewable energy sources in the energy matrix of Peru, especially solar and wind sources. In this scenario, the bilateral conversion systems of DC and AC energies [5] are of great importance, we seek to have an efficient behavior and with advanced control techniques that allow us to reduce harmonic distortions, as well as to have the robustness before disturbances and minimize eventual instabilities that occur when connecting to the public electric distribution networks [2], (in a quantified way, the objective is to have less than 2% in THD, in the variable of interest). The development is done through the application of Predictive Control Based on Models in its version of application called Finite Commutation Set ("Finite Commutation Set" FCS), so the control units of the power stage are implemented with MPC-FCS control. The main results obtained using simulation tools (Matlab and PSIM) applied to these electronic power systems are shown (research objectives are established to achieve electrical efficiencies above 98%). This study takes into account the measurement of the magnitude and direction of the flow of power and electrical energy between the generation sources, the grid, the load and the energy storers. The most significant results are presented, which show the results and the methodology, which, in short, performs better than those do, implemented with widely used methods such as SVPWM. Keywords: Renewable energies, distributed generation, electronic power converters, MPC- FCS, THD.


Author(s):  
Lazhar Bougouffa ◽  
Abdelaziz Chaghi

<p>The use of Distributed Renewable Energy Sources in the electrical network has expanded greatly. But, integration of these resources into distribution systems caused more problems in protection related issues such as mis-coordination, and changes the direction and value of fault currents. When connecting new D-RES to electrical power distribution networks, it is required to re-coordinate Directional Over-CurrentRelays (DOC-Relays) to ensure the continuity of the power transmission when the short circuits take place. This work presented a Particle Swarm Optimization (PSO) algorithm to determine two independent variables called Pickup current (Ip) and Time Dial Setting (TDS) for optimal setting of relays. From analysis result, the impacts of RES location in the distribution system on DOCRs had been observed on the optimal relays settings</p>


Sign in / Sign up

Export Citation Format

Share Document