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- Predictable impact of lighting control on the energy consumption of a building through computational simulationPublication . Bernardo, H.; Leitão, S.; Neves, L.; Amaral, P.; Bernardo, Hermano; Pires Neves, LuísBuilding energy simulation tools provide accurate predictions of the energetic performance of buildings and thermal comfort of its occupants, allowing an evaluation of the impact of proposed improvement measures, in order to support choice for the more economically viable. This paper aims at determining the energy saving potential that can be obtained by adequate measures and investments. It presents the simulated values of the impact on the energy consumptions of a building, caused by artificial lighting control systems set to maximize use of natural lighting. Results show that optimization measures have a significant impact on energy consumptions reduction, and lead to important economical savings.
- Using clustering techniques to provide simulation scenarios for the smart gridPublication . Miguel, Pedro; Gonçalves, José; Pires Neves, Luís; Martins, A. GomestThe objective of this work is to obtain characteristic daily profiles of consumption, wind generationand electricity spot prices, needed to develop assessments of two different options commonly regardedunder the smart grid paradigm: residential demand response, and small scale distributed electric energystorage. The approach consists of applying clustering algorithms to historical data, namely using a hierar-chical method and a self-organizing neural network, in order to obtain clusters of diagrams representingcharacteristic daily diagrams of load, wind generation or electricity price. These diagrams are useful notonly to analyze different scenarios of combined existence, but also to understand their individual relativeimportance. This study enabled also the identification of a probable range of variation around an averageprofile, by defining boundary profiles with the maximum and minimum values of any cluster prototypes.
- Methodology for real impact assessment of the best location of distributed electric energy storagePublication . Gonçalves, José; Martins, António; Pires Neves, LuísThis paper presents a methodology to provide a decision maker, e.g. the distribution system operator,information on the associated impacts of the operation of distributed electric energy storage systems(ESS1) in an urban environment, in order to support the choice of the best locations of storage units. Thedeveloped methodology uses three types of profile prototypes based on actual data, obtained throughclustering techniques. These profiles, which include electricity demand, electricity prices and renewableelectricity production, are used to optimize the placement of electric energy storage units. The paper con-siders expected attitudes of the main stakeholders towards distributed electric ESS implementation, anddiscusses possible regulatory framework options to define the distributed electric ESS business model.The model was applied to a case study using the nanophosphate lithium-ion battery technology as anexample. Results show a significant influence of the charge/discharge profile of batteries on the choiceof their best locations.
- Diseño de Redes Eléctricas Inteligentes para una Gestión EnergéticaPublication . Vélez, Ney R. Balderramo; Albuerne, Yolanda E. Llosas; Neves, Luís; Álava, Lenin A. CuencaEste documento presenta el diseño de una red eléctrica inteligente que permita gestionar de forma eficiente el consumo energético del edificio Nº 3 de docentes de la UTM. Por tal razón, se utilizan las técnicas y herramientas de IA e IC con la finalidad de encontrar un sistema que se adapte a las situaciones requeridas por el sistema eléctrico de la edificación. Con las consideraciones antes mencionadas se utilizó una arquitectura de RNA con RBF, la cual analizará los diferentes parámetros eléctricos con la finalidad de brindar los resultados esperados con los que se pueda dar paso a la toma de decisión que tendrá la red eléctrica inteligente. El sistema desarrollado fue implementado en el entorno Matlab 2018a.
- Using SSM to rethink the analysis of energy efficiency initiativesPublication . Neves, Luís Miguel Pires; Martins, António Gomes; Antunes, Carlos Alberto Henggeler; Dias, Luís Miguel CândidoThis paper reflects an attempt to rethink the process of analysis of energy efficiency initiatives using soft systems methodology (SSM) as a problem structuring tool. The aim of the work is to provide public and private initiative promoters or evaluators with a structured support for a more informed decision regarding the implementation of energy efficiency measures. The SSM approach contributed with the identification of all market players and their relations, as well as the insight into the deficiencies of current methodologies. Some future work directions are also proposed.
- Structuring an MCDA model using SSM: A case study in energy efficiencyPublication . Neves, Luís Miguel Pires; Dias, Luís Miguel Cândido; Antunes, Carlos Alberto Henggeler; Martins, António GomesThis work presents the use of a problem structuring method, Soft Systems Methodology (SSM), to structure a Multi-Criteria Decision Analysis (MCDA) model, aimed at appraising energy efficiency initiatives. SSM was useful to help defining clearly the decision problem context and the main actors involved, as well as to unveil the relevant objectives for each stakeholder. Keeney’s Value Focused Thinking approach was then used to refine and structure the list of objectives according to the perspective of the main evaluators identified. In addition to describing this particular case study, this paper aims at providing some general guidelines on how SSM may facilitate the emergence of objectives for MCDA models.
- High performance position control of permanent magnet synchronous drivesPublication . Pesántez, António; Neves, Luís; Sempertegui, RodrigoIn the design and test of electric drive control systems, computer simulations provide a useful way to verify the correctness and efficiency of various schemes and control algorithms before the final system is actually constructed, therefore, reducing development time and associated costs. Nevertheless, the transition from the simulation stage to the actual implementation has to be as straightforward as possible. This paper presents the design and implementation of a position control system for permanent magnet synchronous drives using the dsPIC33FJ32MC204 microcontroller as the target processor to implement the control algorithms. The overall system is simulated and tested in Proteus VSM software which is able to simulate the interaction between the firmware running on the microcontroller and the analogue circuits connected to it. The electric drive model is developed using elements present in the Proteus VSM library. As in any high-performance AC electric drive system, field oriented control is applied. The complete control system is distributed in three control loops, namely torque, speed and position. A standard PID control system, and a hybrid control system based on fuzzy logic, are implemented and tested. The natural variation of motor parameters, such as winding resistance and magnetic flux, are also simulated. Comparisons between the two control schemes are carried out for speed and position control using different error measurements, such as, integral square error, integral absolute error and root mean squared error. Comparison results show a superior performance of the fuzzy-logic-based controller when coping with parameter variations, and by reducing torque ripple, but the results are reversed when periodical torque disturbances are present.
- A multi-criteria decision approach to sorting actions for promoting energy efficiencyPublication . Neves, Luís Miguel Pires; Martins, António Gomes; Antunes, Carlos Alberto Henggeler; Dias, Luís Miguel CândidoThis paper proposes a multi-criteria decision approach for sorting energy efficiency initiatives, promoted by electric utilities, with or without public funds authorized by a regulator, or promoted by an independent energy agency, overcoming the limitations and drawbacks of Cost-Benefit Analysis. The proposed approach is based on the ELECTRE-TRI multi-criteria method and allows the consideration of different kinds of impacts, although avoiding difficult measurements and unit conversions. The decision is based on all the significant effects of the initiative, both positive and negative ones, including ancillary effects often forgotten in cost-benefit analysis. The ELECTRE-TRI, as most multi-criteria methods, provides to the Decision Maker the ability of controlling the relevance each impact can have on the final decision in a transparent way. The decision support process encompasses a robustness analysis, which, together with a good documentation of the parameters supplied into the model, should support sound decisions. The models were tested with a set of real-world initiatives and compared with possible decisions based on Cost-Benefit analysis.
- Computation of nodal marginal prices in the presence of load and generation cost UncertaintiesPublication . Gomes, B.A.; Tomé Saraiva, João; Neves, L.M.P.Marginal prices have been recognized as the core approach to the economic evaluation of generation and transmission services in an electricity market environment. In this context, this paper presents the New Fuzzy Optimal Power Flow algorithm as a model to addresses the impact of load and generation cost uncertainties in nodal marginal prices. Since loads and generation costs are represented by fuzzy numbers, nodal marginal prices will no longer be represented by deterministic values, but rather by fuzzy membership functions reflecting the specified uncertainties. The paper also presents the algorithm used for the integration of the transmission losses effect on the results. Since the proposed algorithm uses multiparametric programming techniques, it contributes to characterize in a better way the system behavior. Finally, it includes results based on the IEEE 24 bus/38 branch test system to illustrate the proposed approach.
- Short-term load forecasting using information obtained from low voltage load profilesPublication . Sousa, João; Pires Neves, Luís; Humberto M.M. JorgeRecent researches in load forecasting are quite often based on the use of neural networks in order to predict a specific variable (maximum demand, active electric power or hourly consumption) using past values of the same variable and other exogenous factors proved to influence the value being predicted. This work aims to explore different input patterns in neural networks incorporating information derived from load profiles of different consumers' classes.