1,721,077 research outputs found
Performance Metrics For Renewable Energy Communities
No full textEnergy communities have been defined in recent European directives and are being integrated into the Italian regulatory framework. They present themselves as an innovative entity in the national and international energy landscape capable of contributing to the energy transition process through locally produced energy, its self-consumption and sharing with energy community users. Local energy communities are considered an empowerment tool for end users who take charge of the distributed production and management of the energy asset, but in order for the energy asset to be put to its best, most efficient and effective use, it is necessary to develop key performance indices that are also easily understood by community members, whether they are elderly, young people, private companies, public entities, etc., and to which it is immediate to react with proactive behaviour in order to maximize their economic benefits, which, of course, translate locally into environmental and social benefits. In this context, the manuscript presents some performance indices that can be used to achieve the above goals. An energy community case study is discussed to show the purpose and usefulness of the proposed metrics
Evaluation of uncertainty in measurements based on digitized data
No full textThe paper deals with the uncertainty in measurement based on digital signal processing algorithms, like those achievable with the virtual instruments. The correct estimation of bias and uncertainty is discussed with reference to a simple case study. Three possible approaches to this question are examined and compared. It is shown how a Monte Carlo method, based on numerical simulations and implemented with commercial software packages, can allow virtual instruments to perform an auto-evaluation of both bias and uncertainty affecting their results. Some theoretical considerations, computer simulations and experimental tests are shown to support the proposed technique
Smart inverter operation in distribution networks with high penetration of photovoltaic systems
Full text linkWith the growing number and capacity of photovoltaic (PV) installations connected to distribution networks, power quality issues related to voltage regulation are becoming relevant problems for power distribution companies and for PV owners. In many countries, like Italy, this has required the revision of the standards concerning the connection to the public distribution network of distributed renewable generation. The new standards require a flexible operation of generation plants that have to be capable to change the active and reactive power dynamically in function of the network parameters (i.e. frequency and network local voltage) in local control or following external commands. Therefore, this paper investigates the use of smart inverter in a critical PV installation, where relevant voltage fluctuations exist. A case study, with real network parameters monitoring data and measurements, is discussed in the paper with the aim of showing how ‘smart’ features of new inverters can be implemented to increase PV plant integration in low voltage distribution networks
Investigation on unintentional disconnection of photovoltaic plants in LV distribution networks
No full textWith the growing number and capacity of photovoltaic installations connected to distribution networks, power quality issues related to voltage regulation, are becoming relevant problems for power distribution companies and for PV owners. In this context, the paper investigates on unintentional disconnection of photovoltaic plants connected to weak low voltage distribution network. Measurement results put in evidence frequently disconnections of the photovoltaic system, related to relevant voltage fluctuations at the connection point of the active customer, during the operation of its photovoltaic syste
Uncertainty estimation for DSP-based power quality measurements
No full textThis paper deals with the uncertainty in digital measurement systems designed for power quality applications. The main goal of this work is to evaluate such uncertainty by means of a Monte Carlo method recently proposed in the literature. The accuracy of the measurement result obtained with a DSP-based instrument for power quality metering depends on the behavior of the devices located in both the conditioning block and A/D conversion stage: it is thus necessary to consider the uncertainties introduced by each component of the system and the propagation of their effects through the measurement chain. Here, the uncertainty is estimated starting from the technical specifications provided by the manufacturers of these devices. Experimental results are reported to show the importance of some concerns about the practical implementation of the proposed methodology in a real instrument
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