Pôle-generació a Goundi

Postprint (published version

Voltage disturbance monitoring

Publication of a report for the Leonardo Power Quality InitiativePostprint (author's final draft

Automatització industrial amb GRAFCET

Aquest text pretén donar una visió aprofundida del GRAFCET com a mètode de descripció d'automatismes seqüencials en general i per a la programació d'autòmats programables en particular. A més descriu la guia GEMMA, que sistematitza la gestió dels modes de funcionament, les emergències i les avaries des del sistema d'automatització. Al final s'exposen dos mètodes (un de general i l'altre simplificat) per implementar automatismes dissenyats en GRAFCET sobre autòmats que es programen en diagrama de contactes (ladder). Per facilitar la comprensió i la presa de contacte, el text inclou exemples senzills

Simple maximum power point controller for single-phase grid-connected PV system

This paper proposes a simple and efficient PI controller for single-phase grid-connected PV generator. The controller ensures the system operation at maximum power point (MPP) irrespective to atmospheric conditions. A detailed design of the controller and DC capacitor were carried out. An averagevalue model was developed to facilitate the design of the controller and to study the system performance under different operation conditions. The results were validated by rigorous simulation.Peer ReviewedPostprint (published version

Autonomous photovoltaic lighting system

This paper introduces a comparison between the conventional and Photovoltaic (PV) lighting systems. A simple sizing procedure for a PV stand-alone system was advised. The paper also proposes a novel PV lighting system. The proposed system is simple, compact and reliable. The system operation was investigated by thoroughly mathematical and simulation work.Postprint (published version

Sensorless control of a power converter for a cluster of small wind turbines

This study presents a new sensorless control for small wind turbine clusters with a single power converter with a direct torque control algorithm. The proposed system consists of a wind farm connected to a back-to-back power converter that interfaces the wind farm with the AC grid. The studied wind turbines are based on fixed-speed wind turbines equipped with squirrel cage induction generators with individual pitch control. The presented structure permits to reduce the number of converters and allows to accomplish the grid codes (fault ride through capability and reactive power support). Furthermore, the generated active power can be reduced according to grid operator requirements. The presented control scheme can be applied to wind turbine repowering projects, wind farms connected to a microgrid, even, new small onshore and offshore power plants. The system performance and stability is studied and validated by means of dynamic simulations.Postprint (author's final draft

Fuzzy Numbers Based Algorithm for Interruptions Frequency Estimation on Distribution Smart Grids

The reliability of a distribution system can be considered from the point of view of a particular customer or from the entire supply system, e.g. average interruption frequency (SAIFI) and system average interruption duration (SAIDI). The reliability indices which are referring at the interruption frequency are mainly influenced by the adopted operational configuration and the minimization in operation of SAIFI represents an important aim. A substantial change in the power distribution systems behavior appears because of the large-scale introduction of distributed generation as distributed generators connected directly to the main distribution system or inside of microgrids which are also connected to the main distribution system. In the paper, authors propose an original fuzzy based method for the estimation of the average interruption frequency on distribution smart grids

Pareto optimal reconfiguration of power distribution systems using a genetic algorithm based on NSGA-II

Reconfiguration, by exchanging the functional links between the elements of the system, represents one of the most important measures which can improve the operational performance of a distribution system. The authors propose an original method, aiming at achieving such optimization through the reconfiguration of distribution systems taking into account various criteria in a flexible and robust approach. The novelty of the method consists in: the criteria for optimization are evaluated on active power distribution systems (containing distributed generators connected directly to the main distribution system and microgrids operated in grid-connected mode); the original formulation (Pareto optimality) of the optimization problem and an original genetic algorithm (based on NSGA-II) to solve the problem in a non-prohibitive execution time. The comparative tests performed on test systems have demonstrated the accuracy and promptness of the proposed algorithm.Postprint (published version

Study of optimization design criteria for stand-alone hybrid renewable power systems

Hybrid renewable power systems integrate two or more sources of energy, one of which is renewable, optionally a storage system and typically work in stand-alone mode. They are being considered more and more and we should increment their usage taking advantage of their positive benefits: free of charge resource availability, CO2 emissions reductions and subsidies. Dealing with their inconveniences: variability of renewable resources availability and cost acquisition, through the optimization of the design and the control of the system. The optimal design of hybrid renewable power systems is usually defined by economic criteria. But there are also technical and environmental criteria to be taken into account to improve decision-making. In this paper a discussion on different criteria will introduce the non-economical perspectives in addition to the economic criteria. A case study of a PV-Wind-Diesel-Battery system for a Telecommunication station in Catalonia is discussed. Availability of renewable energy sources is obtained with RETScreen and PVSyst. Analysis and simulations of various hybrid power systems have been done in HOMER resulting on a comparison of different scenarios. Optimal scenario taking into account the best results of all three types of criteria: economic, technical and environmental, is a trade-off of the economic optimum.Postprint (published version

Software Tool for the Analysis of Electromagnetic Disturbances Propagation

The analysis of the conducted electromagnetic disturbances propagation is a complex issue, involving detection and analysis of electromagnetic disturbances, modelling of power grids’ elements, and study of the influenceon the grids’ elements (electric lines and power transformers)of the existing disturbances.Postprint (published version