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

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

Tesi per compendi de publicacions, amb una secció retallada pels drets d'editorThis 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 infraestructuraPostprint (published version

Optimization of the operation of smart rural grids through a novel rnergy management system

The paper proposes an innovative Energy Management System (EMS) that optimizes the grid operation based on economic and technical criteria. The EMS inputs the demand and renewable generation forecasts, electricity prices and the status of the distributed storages through the network, and solves with an optimal quarter-hourly dispatch for controllable resources. The performance of the EMS is quantified through diverse proposed metrics. The analyses were based on a real rural grid from the European FP7 project Smart Rural Grid. The performance of the EMS has been evaluated through some scenarios varying the penetration of distributed generation. The obtained results demonstrate that the inclusion of the EMS from both a technical point of view and an economic perspective for the adopted grid is justified. At the technical level, the inclusion of the EMS permits us to significantly increase the power quality in weak and radial networks. At the economic level and from a certain threshold value in renewables’ penetration, the EMS reduces the energy costs for the grid participants, minimizing imports from the external grid and compensating the toll to be paid in the form of the losses incurred by including additional equipment in the network (i.e., distributed storage).Postprint (published version

Consecuencias de los robos de las puestas a tierras en las redes de distribución de media y baja tensión

Postprint (published version

Estudio técnico sobre la calidad del suministro en redes de distribución: Análisis de la secuencia de desconexión y reconexión de las líneas de media tensión

Postprint (published version

Smart grids for rural conditions and e-mobility - Applying power routers, batteries and virtual power plants

Significant reductions of greenhouse gas emission by use of renewable energy sources belong to the common targets of the European Union. Smart grids address intelligent use and integration of conventional and renewable generation in combination with controllable loads and storages. Two special aspects have also to be considered for smart grids in future: rural conditions and electric vehicles. Both, the increasing share of renewable energy sources and a rising demand for charging power by electrical vehicles lead to new challenges of network stability (congestion, voltage deviation), especially in rural distribution grids. This paper describes two lighthouse projects in Europe (“Well2Wheel” and “Smart Rural Grid”) dealing with these topics. The link between these projects is the implementation of the same virtual power plant technology and the approach of cellular grid cells. Starting with an approach for the average energy balance in 15 minutes intervals in several grid cells in the first project, the second project even allows the islanded operation of such cells as a microgrid. The integration of renewable energy sources into distribution grids primary takes place in rural areas. The lighthouse project “Smart Rural Grid”, which is founded by the European Union, demonstrates possibilities to use the existing distribution system operator infrastructure more effectively by applying an optimised and scheduled operation of the assets and using intelligent distribution power routers, called IDPR. IDPR are active power electronic devices operating at low voltage in distribution grids aiming to reduce losses due to unbalanced loads and enabling active voltage and reactive power control. This allows a higher penetration of renewable energy sources in existing grids without investing in new lines and transformers. Integrated in a virtual power plant and combined with batteries, the IDPR also allows a temporary islanded mode of grid cells. Both projects show the potential of avoiding or postponing investments in new primary infrastructure like cables, transformers and lines by using a forward-looking operation which controls generators, loads and batteries (mobile and stationary) by using new grid assets like power routers. While primary driven by physical restrictions as voltage-band violations and energy balance, these cells also define and allow local smart markets. In consequence the distribution system operators could avoid direct control access by giving an incentive to the asset owners by local price signals according to the grid situation and forecasted congestions.Peer ReviewedPostprint (published version

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

Short-term energy storage for power quality improvement in weak MV grids with distributed renewable generation

The intermittent and stochastic nature of renewable energy sources impose several challenges for the operation of electrical networks, and affect power quality levels as well. This paper addresses one of the issues associated to power quality in electrical networks: voltage flicker. The main contribution of the paper fall in the proposal of a methodology for addressing the location in the network and the sizing of an active filter for flicker filtering. The designed active filter is based on controllable and bidirectional power electronics. Also, it includes energy storage capability, so as to maximize flicker filtering effectiveness by performing both active and reactive power regulation.Postprint (author's final draft

A power sharing algorithm for a hybrid energy storage system based on batteries

© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other worksThis paper presents a method to operate a hybrid Energy Storage System (ESS) based on a heterogeneous grouping of battery types. In particular, the system is composed by a lithium-ion battery pack and a lead-acid one. The operational method is based on an optimization Non Linear Problem (NLP), which takes the name of power sharing algorithm. The aim of this algorithm is to fit the output of the hybrid ESS to the profile setpoint while minimizing degradation and taking advantage of main performance of each battery type. An exemplary study case is offered so as to proof the validity of the algorithm.Postprint (author's final draft

La primera feria autosostenible con anilla energética autónoma

El 2 y 3 de noviembre del 2019 tuvo lugar en Barcelona la novena edición de la feria de la movilidad eléctrica, Expoelectric. Esta feria es una iniciativa pionera que acerca el vehículo eléctrico de cero emisiones y las energías renovables a la ciudadanía a través de un conjunto de actividades lúdicas y divulgativas para impulsar la movilidad eléctrica y la transición energéticaPostprint (published version