PV Hosting Capacity Analysis and Enhancement Using High Resolution Stochastic Modeling

Reduction of CO2 emissions is a main target in the future smart grid. This goal is boosting the installation of renewable energy resources (RES), as well as a major consumer engagement that seeks for a more efficient utilization of these resources toward the figure of ‘prosumers’. Nevertheless, these resources present an intermittent nature, which requires the presence of an energy storage system and an energy management system (EMS) to ensure an uninterrupted power supply. Moreover, network-related issues might arise due to the increasing power of renewable resources installed in the grid, the storage systems also being capable of contributing to the network stability. However, to assess these future scenarios and test the control strategies, a simulation system is needed. The aim of this paper is to analyze the interaction between residential consumers with high penetration of PV generation and distributed storage and the grid by means of a high temporal resolution simulation scenario based on a stochastic residential load model and PV production records. Results of the model are presented for different PV power rates and storage capacities, as well as a two-level charging strategy as a mechanism for increasing the hosting capacity (HC) of the network

Hall-Effect Based Semi-Fast AC On-Board Charging Equipment for Electric Vehicles

The expected increase in the penetration of electric vehicles (EV) and plug-in hybrid electric vehicles (PHEV) will produce unbalanced conditions, reactive power consumption and current harmonics drawn by the battery charging equipment, causing a great impact on the power quality of the future smart grid. A single-phase semi-fast electric vehicle battery charger is proposed in this paper. This ac on-board charging equipment can operate in grid-to-vehicle (G2V) mode, and also in vehicle-to-grid (V2G) mode, transferring the battery energy to the grid when the vehicle is parked. The charger is controlled with a Perfect Harmonic Cancellation (PHC) strategy, contributing to improve the grid power quality, since the current demanded or injected has no harmonic content and a high power factor. Hall-effect current and voltage transducers have been used in the sensor stage to carry out this control strategy. Experimental results with a laboratory prototype are presented

Active, Reactive and Harmonic Control for Distributed Energy Micro-Storage Systems in Smart Communities Homes

This paper aims to provide control strategies for distributed micro-storage energy systems at the residential level to contribute to smart grid goals. A simulation model of an energy storage system (ESS) charger has been implemented to test these proposed control strategies. The smart community energy management system (SCEMS), acting as an aggregator of resources in the community according to the expected demand and production, sends to each individual home the active and reactive power set-points. Besides, in case the ESS has available capacity, once the SCEMS requirements are satisfied, it is used to absorb the harmonic current components demanded by the household circuitry. It allows a local improvement in the power quality of the demanded current, and thus contributes to the global power quality consumption of the community. Simulation results showing the operation of a local ESS at a home in a Smart Community are presented to validate the proposed control strategies

Improved forecasting-based battery energy management strategy for prosumer systems

Publicado en IECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society, Washington D. C., 2018, pp. 6077-6082, doi: 10.1109/IECON.2018.8592892Este trabajo presenta una estrategia de gestión de energía basada en la programación de la operación de la batería en sistemas prosumidores según los datos de pronóstico disponibles con 24 horas de anticipación. El método propuesto busca alcanzar un compromiso beneficioso entre los prosumidores y los operadores de la red de distribución, independientemente del contexto económico específico o las regulaciones técnicas. Se lleva a cabo una mejora para hacer frente a la imprecisión del pronóstico. Los resultados demuestran que ofrece buenas propiedades con respecto a la gestión de energía, con una estimación de reserva de energía almacenada, preservación de la vida útil de la batería y mejora del autoconsumo y la autosuficiencia.This work presents an energy management strategy based on scheduling battery operation in prosumer systems, according to forecast data available 24 hours in advance. The proposed method seeks to reach a beneficial compromise between prosumers and distribution grid operators, independently of specific economic context or technical regulations. An improvement to deal with forecast inaccuracy is carried out. Results demonstrate that it offers good properties regarding energy management, with a stored energy reserve estimation, battery lifetime preservation and self-consumption and selfsufficiency enhancement.peerReviewe

Improvements on the carrier-based control method for a three-level T-type, quasi-impedance-source inverter

The boost feature that characterizes Z-source and quasi-Z-source converters is usually achieved by means of a proper insertion of short-circuit states in the full DC-link. In this work, a novel pulse width modulation carrier-based strategy for a three-phase, three-level T-type, quasi-Z-source inverter is introduced, based on the addition of alternate short-circuits in the two halves of the DC-link bus. This technique achieves better performance, less electromagnetic interference, and lower harmonic distortion of the output line-to-line voltage compared to the traditional methods based on the full DC-link shoot-through. At the same time, generating the switching states is to easy implement. The proposed strategy permits the use of electronic devices with lower blocking voltage capability, thus improving converter reliability, size, and cost. The new method may be implemented in another multilevel inverter with an impedance-source network as well. A comprehensive simulation study is performed in order to validate the adopted method, with different inverter input voltages, which is taken as representative of a photovoltaic array. Comparisons are conducted with conventional strategy insertions using the same topology in order to show the improvements achieved.• Junta de Extremadura (Regional Government), Spain. Programa de Becas de Movilidad para Personal Docente e Investigador de la Comunidad Autónoma de Extremadura 2018, por el fondo para el grupo de investigación (GR18087) y el proyecto regional (IB18067). • Agencia Estatal de Investigación (AEI) y Fondo Europeo de Desarrollo Regional (FEDER) españoles, bajo el Proyecto TEC2016-77632-C3-1-R (AEI / FEDER, UE), y a través de FCT bajo los contratos UID / CEC / 50021/2019 , Pest-E / EEI / LA0021 / 2014 y UID / Multi / 00308/2019.peerReviewe

A smart power electronic multiconverter for the residential sector

El futuro de la red incluye la generación distribuida y las tecnologías de red inteligente. Los sistemas de gestión del lado de la demanda (DSM) también serán esenciales para lograr un alto nivel de confiabilidad y robustez en los sistemas de energía. Para hacer eso, es necesario expandir la Infraestructura de medición avanzada (AMI) y los Sistemas de gestión de energía (EMS). La dirección de la tendencia es hacia la creación de centros de recursos energéticos, como el concepto de comunidad inteligente. Este documento presenta un sistema multiconvertidor inteligente para el sector residencial / vivienda con un Sistema de Almacenamiento de Energía Híbrido (HESS) que consta de supercapacitador y batería, y con integración de fuente de energía fotovoltaica (PV) local. El dispositivo funciona como una unidad de energía distribuida ubicada en cada casa de la comunidad, recibiendo puntos de ajuste de energía activos proporcionados por una comunidad inteligente EMS. Este SGA central es responsable de administrar los flujos de energía activa entre la red eléctrica, las fuentes de energía renovables, los equipos de almacenamiento y las cargas existentes en la comunidad. El multiconvertidor propuesto es responsable de cumplir con los puntos de referencia de potencia activa de referencia con la calidad de potencia adecuada; garantizando que los módulos fotovoltaicos locales funcionen con un algoritmo de seguimiento del punto de máxima potencia (MPPT); y prolongando la vida útil de la batería gracias a un funcionamiento cooperativo del HESS. Se ha desarrollado un modelo de simulación para mostrar el funcionamiento detallado del sistema. Finalmente, se implementó un prototipo de la plataforma de multiconversores y se realizaron algunas pruebas experimentales para validarlo.The future of the grid includes distributed generation and smart grid technologies. Demand Side Management (DSM) systems will also be essential to achieve a high level of reliability and robustness in power systems. To do that, expanding the Advanced Metering Infrastructure (AMI) and Energy Management Systems (EMS) are necessary. The trend direction is towards the creation of energy resource hubs, such as the smart community concept. This paper presents a smart multiconverter system for residential/housing sector with a Hybrid Energy Storage System (HESS) consisting of supercapacitor and battery, and with local photovoltaic (PV) energy source integration. The device works as a distributed energy unit located in each house of the community, receiving active power set-points provided by a smart community EMS. This central EMS is responsible for managing the active energy flows between the electricity grid, renewable energy sources, storage equipment and loads existing in the community. The proposed multiconverter is responsible for complying with the reference active power set-points with proper power quality; guaranteeing that the local PV modules operate with a Maximum Power Point Tracking (MPPT) algorithm; and extending the lifetime of the battery thanks to a cooperative operation of the HESS. A simulation model has been developed in order to show the detailed operation of the system. Finally, a prototype of the multiconverter platform has been implemented and some experimental tests have been carried out to validate it.Ministerio de Economía y Competitividad (España) y Fondos FEDER: Proyecto TEC2013-47316-C3-3-PpeerReviewe

Caracterización de las tipologías del medio físico construido en frentes de playa: Municipio Guamá (Cuba)

Determining the characteristics and differentiated behaviors of the processes of land occupation and urban consolidation on beach fronts, is a necessary precedent for the conception of intervention actions and land use planning in coastal areas.  The present article aims to characterize the assumed beach fronts typologies: 1) urban beach frontage; 2) settlement beachfront and 3) resort-associated beachfront.  For this, a characterization procedure was structured from 16 analysis variables grouped into 4 categories, which allow identifying the similarities and divergences that manifest the components of the physical environment built in each typology.  The procedure was validated on three beach fronts of Guama municipality of Santiago de Cuba province, Cuba.  The main conclusion indicates that the variables with the greatest differentiation between the identified typologies are those related to the Functional Structuring category.Determinar las características y comportamientos diferenciados de los procesos de ocupación del suelo y consolidación urbana en frentes de playa, resulta un antecedente necesario a la concepción de acciones de intervención y ordenamiento territorial en espacios litorales. El presente artículo, tiene como objetivo caracterizar las tipologías de frentes de playa asumidas: 1) frente de playa urbano; 2) frente de playa de asentamiento y 3) frente de playa asociado a complejo turístico. Para ello se estructuró un procedimiento de caracterización a partir de 16 variables de análisis agrupadas en 4 categorías, que permiten identificar las similitudes y divergencias que manifiestan los componentes del medio físico construido en cada tipología. El procedimiento fue validado en tres frentes de playas del municipio Guamá de la provincia Santiago de Cuba, Cuba. La principal conclusión indica que las variables de mayor diferenciación entre las tipologías identificadas son los relacionados con la categoría Estructuración Funcional

Secondary Control for Storage Power Converters in Isolated Nanogrids to Allow Peer-to-Peer Power Sharing

It is usual in literature that power sharing among grid-forming sources of an isolated microgrid obeys their energy rating, instead of economic agreements between stakeholders, and circulating energy among them is usually avoided. However, these energy interchanges make strong sense and classical power sharing methods must be reformulated in the context of prosumer-based microgrids. This paper proposes a secondary control method for a prosumer-based low-voltage nanogrid that allows for energy interchange between prosumers, where storage systems, together with PV generators, are the controllable grid-forming sources. A power flow technique adapted to islanded microgrids is used for secondary control algorithm and the whole hierarchical control strategy for the prosumer converter is simulated and validated. This hierarchical control consists of three stages: tertiary control plans the energy interchange among prosumers, secondary obtains different voltage and power setpoints for each of the grid-forming sources, and, finally, primary control guarantees stable voltage and frequency values within the nanogrid with droop rules. Inner control loops for the power converter are also defined to track setpoints and assure stable performance. Simulation tests are carried out, which prove the stability of the proposed methods and the accuracy of the setpoint tracking

Photovoltaic Power Converter Management in Unbalanced Low Voltage Networks with Ancillary Services Support

TEC2016-77632-C3-1-R (AEI/FEDER, UE) Sem PDF conforme despacho.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.publishersversionpublishe

Estudio comparativo de estrategias de gestión de energía en microrredes de prosumidores

Comunicación presentada al XXV Seminario Anual de Automática, Electrónica Industrial e Instrumentación, celebrado el 4, 5 y 6 de Julio 2018 en BarcelonaEn el panorama actual, el sistema eléctrico debe estar preparado para integrar fuentes de energía renovables, sistemas de almacenamiento de energía e instalaciones de prosumidores, muchas veces organizados en microrredes, y además de la forma más eficiente y fiable posible. Este trabajo propone dos estrategias de gestión de energía aplicadas a microrredes de prosumidores con generación fotovoltaica y almacenamiento en baterías, basadas en la cooperación entre prosumidores, que comparten la energía excedentaria de su instalación para reducir el déficit energético y cargar las baterías de otros prosumidores de la microrred, con lo que se disminuye su dependencia global de la red principal. Las estrategias propuestas se han validado mediante un caso de simulación y los resultados obtenidos han sido evaluados desde el punto de vista energético y económico.In the current scenario, the electrical system must be prepared to integrate renewable energy sources, energy storage systems and prosumer facilities, often organized in microgrids, and in the most efficient and reliable way possible. This paper proposes two energy management strategies applied to micro-networks of prosumers with photovoltaic generation and battery storage, based on cooperation between prosumers, who share the surplus energy of their installation to reduce the energy deficit and charge the batteries of other prosumers the microrred, which decreases its global dependence on the main network. The proposed strategies have been validated through a simulation case and the results obtained have been evaluated from an energy and economic point of view.Agencia Estatal de Investigación (AEI) y Fondo Europeo de Desarrollo Regional (FEDER): Proyecto TEC2016-77632-C3-1-R (AEI/FEDER, UE