Analysis of the dynamic performance of self-excited induction generators employed in renewable energy generation

Incentives, such as the Feed-in-tariff are expected to lead to continuous increase in the deployment of Small Scale Embedded Generation (SSEG) in the distribution network. Self-Excited Induction Generators (SEIG) represent a significant segment of potential SSEG. The quality of SEIG output voltage magnitude and frequency is investigated in this paper to support the SEIG operation for different network operating conditions. The dynamic behaviour of the SEIG resulting from disconnection, reconnection from/to the grid and potential operation in islanding mode is studied in detail. The local load and reactive power supply are the key factors that determine the SEIG performance, as they have significant influence on the voltage and frequency change after disconnection from the grid. Hence, the aim of this work is to identify the optimum combination of the reactive power supply (essential for self excitation of the SEIG) and the active load (essential for balancing power generation and demand). This is required in order to support the SEIG operation after disconnection from the grid, during islanding and reconnection to the grid. The results show that the generator voltage and speed (frequency) can be controlled and maintained within the statuary limits. This will enable safe disconnection and reconnection of the SEIG from/to the grid and makes it easier to operate in islanding mode

Smart grid architecture for rural distribution networks: application to a Spanish pilot network

This paper presents a novel architecture for rural distribution grids. This architecture is designed to modernize traditional rural networks into new Smart Grid ones. The architecture tackles innovation actions on both the power plane and the management plane of the system. In the power plane, the architecture focuses on exploiting the synergies between telecommunications and innovative technologies based on power electronics managing low scale electrical storage. In the management plane, a decentralized management system is proposed based on the addition of two new agents assisting the typical Supervisory Control And Data Acquisition (SCADA) system of distribution system operators. Altogether, the proposed architecture enables operators to use more effectively—in an automated and decentralized way—weak rural distribution systems, increasing the capability to integrate new distributed energy resources. This architecture is being implemented in a real Pilot Network located in Spain, in the frame of the European Smart Rural Grid project. The paper also includes a study case showing one of the potentialities of one of the principal technologies developed in the project and underpinning the realization of the new architecture: the so-called Intelligent Distribution Power Router.Postprint (published version

EcoBlock: Grid Impacts, Scaling, and Resilience

Widespread deployment of EcoBlocks has the potential to transform today's electricity system into one that is more resilient, flexible, efficient and sustainable. In this vision, the system will consist of self- su cient, renewable-powered, block-scale entities that can deliberately adjust their net power exchange and can optimize performance, maintain stability, support each other, or disconnect entirely from the grid as needed. This report is intended as an independent analysis of the potential relationships, both constructive and adverse, between EcoBlocks and the grid

Power quality and electromagnetic compatibility: special report, session 2

The scope of Session 2 (S2) has been defined as follows by the Session Advisory Group and the Technical Committee: Power Quality (PQ), with the more general concept of electromagnetic compatibility (EMC) and with some related safety problems in electricity distribution systems. Special focus is put on voltage continuity (supply reliability, problem of outages) and voltage quality (voltage level, flicker, unbalance, harmonics). This session will also look at electromagnetic compatibility (mains frequency to 150 kHz), electromagnetic interferences and electric and magnetic fields issues. Also addressed in this session are electrical safety and immunity concerns (lightning issues, step, touch and transferred voltages). The aim of this special report is to present a synthesis of the present concerns in PQ&EMC, based on all selected papers of session 2 and related papers from other sessions, (152 papers in total). The report is divided in the following 4 blocks: Block 1: Electric and Magnetic Fields, EMC, Earthing systems Block 2: Harmonics Block 3: Voltage Variation Block 4: Power Quality Monitoring Two Round Tables will be organised: - Power quality and EMC in the Future Grid (CIGRE/CIRED WG C4.24, RT 13) - Reliability Benchmarking - why we should do it? What should be done in future? (RT 15

Online Control of Modular Active Power Line Conditioner to Improve Performance of Smart Grid

This thesis is explored the detrimental effects of nonlinear loads in distribution systems and investigated the performances of shunt FACTS devices to overcome these problems with the following main contribution: APLC is an advanced shunt active filter which can mitigate the fundamental voltage harmonic of entire network and limit the THDv and individual harmonic distortion of the entire network below 5% and 3%, respectively, as recommended by most standards such as the IEEE-519

Contribution to the operation of smart rural distribution grid with energy resources for improvement of the quality of service

This Thesis aims for contributing in the deployment and operation of Smart Grid, in isolated rural areas. As it would be expected, technological developments and investments in the electrical field have mainly focused on urban and industrial areas where the energy demand is high, as well as, the possibility to recover easily the investment. Therefore, difficult accessing areas where population and electrical demand are low are less attractive to invest. For this reason, this Thesis, in parallel to the European project known as Smart Rural Grid, has focused on the rural grid development. In this sense, the Thesis contributes directly in the design, conception and justification of an innovate architecture for rural systems. The architecture has been deployed and tested at the end of a medium voltage line of Estabanell Energia in Vallfogona del Ripollès. In addition, the presented architecture is characterised to integrate power electronics with embedded battery systems, an innovative management system and a proper telecommunication network in order to gain robustness, flexibility and hosting capacity for distributed and renewable generation. To sum up, the Thesis has focused on the design and development of new operation modes, algorithms and equipment that allow to manage automatically and optimally the energy resources; like power electronics, energy storage systems, distributed and renewable generation, and controllable loads. These strategies are able to correct common issues in rural grids, such as voltage variations and electrical losses. In addition, they improve and ensure the power quality and supply continuity, contribute to reduce operational costs and infrastructure optimization and deferral.Aquesta tesi vol contribuir en el desplegament de les futures xarxes elèctriques intel.ligents, en entorns rurals que habitualment són oblidats. Cal mencionar que els principals avenços tecnològics i les inversions per part dels gestors de la xarxa s'han centrat en entorns urbans i industrials, ja que aquests solen demandar grans quantitats d'energia, fet que facilita la recuperació de la inversió. Per tant, en un entorn on la densitat de població i la demanda energètica és baixa i a més l'orografia és complexa resulta menys atractiu invertir-hi. Per aquest motiu, la tesi, en paral.lel al projecte Europeu Smart Rural Grid, s'ha centrat en el desenvolupament de les xarxes elèctriques en entorns rurals. El principal objectiu de la tesi i alhora del projecte Smart Rural Grid és desenvolupar tecnologies per concebre les futures xarxes en entorns rurals. Aquestes han de permetre incrementar la baixa eficiència, qualitat i resiliència de la xarxa. En aquest sentit, la tesi ha contribuït en la concepció, disseny i justificació d'una innovadora arquitectura. Aquesta arquitectura, s'ha dut a terme en el final d'una línia de mitja tensió d'Estabanell Energia a Vallfogona del Ripollès. A més, aquesta arquitectura es caracteritza per integrar electrònica de potència, sistemes elèctrics d'emmagatzemament, un innovador sistema de gestió i de telecomunicacions, poden proporcionar a la xarxa una major robustesa, flexibilitat i capacitat per integrar a la nova generació distribuïda i renovable. D'altre banda, la Tesi també s'ha centrat en la concepció i desenvolupament de nous modes d'operació, algoritmes i dispositius que permeten automatitzar i optimitzar la gestió dels recursos distribuïts; és a dir, la electrònica de potència, els sistemes d'emmagatzemament, la generació renovable i distribuïda i les càrregues controlables. Aquestes estratègies permeten solventar els problemes habituals en aquest tipus de xarxes, com per exemple les variacions de tensió i les pèrdues. A més, també milloren i asseguren la qualitat i continuïtat del subministrament, ajuden a reduir els costos d'operació i retrassar la inversió en nova infraestructur

Mitigating unbalance using distributed network reconfiguration techniques in distributed power generation grids with services for electric vehicles: A review

© 2019 Elsevier Ltd With rapid movement to combat climate change by reducing greenhouse gases, there is an increasing trend to use more electric vehicles (EVs) and renewable energy sources (RES). With more EVs integration into electricity grid, this raises many challenges for the distribution service operators (DSOs) to integrate such RES-based, distributed generation (DG) and EV-like distributed loads into distribution grids. Effective management of distribution network imbalance is one of the challenges. The distribution network reconfiguration (DNR) techniques are promising to address the issue of imbalance along with other techniques such as the optimal distributed generation placement and allocation (OPDGA) method. This paper presents a systematic and thorough review of DNR techniques for mitigating unbalance of distribution networks, based on papers published in peer-reviewed journals in the last three decades. It puts more focus on how the DNR techniques have been used to manage network imbalance due to distributed loads and DG units. To the best of our knowledge, this is the first attempt to review the research works in the field using DNR techniques to mitigate unbalanced distribution networks. Therefore, this paper will serve as a prime source of the guidance for mitigating network imbalance using the DNR techniques to the new researchers in this field

Grid-Connected Renewable Energy Sources

The use of renewable energy sources (RESs) is a need of global society. This editorial, and its associated Special Issue “Grid-Connected Renewable Energy Sources”, offers a compilation of some of the recent advances in the analysis of current power systems that are composed after the high penetration of distributed generation (DG) with different RESs. The focus is on both new control configurations and on novel methodologies for the optimal placement and sizing of DG. The eleven accepted papers certainly provide a good contribution to control deployments and methodologies for the allocation and sizing of DG

Evolution of the Electricity Distribution Networks : Active Management Architecture Schemes and Microgrid Control Functionalities

The power system transition to smart grids brings challenges to electricity distribution network development since it involves several stakeholders and actors whose needs must be met to be successful for the electricity network upgrade. The technological challenges arise mainly from the various distributed energy resources (DERs) integration and use and network optimization and security. End-customers play a central role in future network operations. Understanding the network’s evolution through possible network operational scenarios could create a dedicated and reliable roadmap for the various stakeholders’ use. This paper presents a method to develop the evolving operational scenarios and related management schemes, including microgrid control functionalities, and analyzes the evolution of electricity distribution networks considering medium and low voltage grids. The analysis consists of the dynamic descriptions of network operations and the static illustrations of the relationships among classified actors. The method and analysis use an object-oriented and standardized software modeling language, the unified modeling language (UML). Operational descriptions for the four evolution phases of electricity distribution networks are defined and analyzed by Enterprise Architect, a UML tool. This analysis is followed by the active management architecture schemes with the microgrid control functionalities. The graphical models and analysis generated can be used for scenario building in roadmap development, real-time simulations, and management system development. The developed method, presented with high-level use cases (HL-UCs), can be further used to develop and analyze several parallel running control algorithms for DERs providing ancillary services (ASs) in the evolving electricity distribution networks.© 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).fi=vertaisarvioitu|en=peerReviewed