1,720,981 research outputs found
Preliminary analysis for the design of an energy-efficient and environmental sustainable integrated mobility system
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DEMO Fusion Power Plant: Preliminary Sizing Analysis of Power System
No full textEU-DEMO is a European project for the design and construction of the first nuclear reactor able to produce electrical energy thanks to thermonuclear fusion reactions. The electrical power system of this facility is particular demanding for several reasons. First, the electrical power required to operate DEMO is expected to be huge, especially in comparison to a conventional nuclear plant. Moreover, the operations are intrinsically intermittent, thus introducing specific problems in terms of energy balance and grid stability. This paper deals with a first preliminary study about the sizing and the design of the DEMO internal electrical power system, with a specific focus on the steady-state loads necessary to operate the plant. The design results are obtained and verified through a model for power flow analysis, implemented in DIgSILENT PowerFactory
Energy analysis for the connection of the nuclear reactor DEMO to the European electrical grid
Full text linkTowards the middle of the current century, the DEMOnstration power plant, DEMO, will start operating as the first nuclear fusion reactor capable of supplying its own loads and of providing electrical power to the European electrical grid. The presence of such a unique and peculiar facility in the European transmission system involves many issues that have to be faced in the project phase. This work represents the first study linking the operation of the nuclear fusion power plant DEMO to the actual requirements for its correct functioning as a facility connected to the power systems. In order to build this link, the present work reports the analysis of the requirements that this unconventional power-generating facility should fulfill for the proper connection and operation in the European electrical grid. Through this analysis, the study reaches its main objectives, which are the definition of the limitations of the current design choices in terms of power-generating capability and the preliminary evaluation of advantages and disadvantages that the possible configurations for the connection of the facility to the European electrical grid can have. In reference to the second objective, the work makes possible a first attempt at defining the features of the point of connection to the European grid,whose knowledge will be useful in the future, for the choice of the real construction site
Active Distribution Grids: Observability and RES-based DG Forecasting
No full textThere are many reasons that have led to the penetration of Renewable Energy Sources based (RES-based) generation plants in the Italian power systems, i.e. the sensitivity to environmental issues, the presence of massive economic incentives and the development of technology. This, with the evolution of electricity markets, introduced new problems in the operation of the transmission and distribution grids. In particular, coordination actions between the Transmission System Operator (TSO) and the Distribution System Operator (DSO) became mandatory for guaranteeing a good operation of the whole power system. A series of resolutions, by the Italian Regulatory Authority for Energy, Networks and Environment (ARERA), has been published, aimed at tracing guidelines and indications to build and to grow the necessary collaboration between TSO and DSO. Areti, DSO in Rome metropolitan area, has decided to participate, in collaboration with Italian TSO, TERNA, in the first forms of experimentation in the field of observability of power flows and the state of RES-based resources spread over the Medium Voltage (MV) networks, as defined in the Authority documents. A system based on models, using neural networks, is proposed for reproducing the behaviour of the RES-based generation plants monitored. The paper presents it, verifying whether the application to cases of real plants is able to produce results compatible with the indications given to achieve the success of the tests
Planning studies for active distribution grids in presence of EVs charging stations: simulation on a real test network
No full textIn the next future, a large spread of Electrical Vehicles (EVs) is foreseen, in accordance with the
European policies and regulation dealing with environmental sustainability. It will lead to an important
number of charging stations connections, whose number will be a function of the demand required by
the EVs (traffic conditions, EV fleet and features, etc.), but they depend also on grid capacity,
considering that they typically represent very variable loads for the grid. A “fit and forget” approach
could involve the violation of grid operation limits and so the need of grid reinforcements (new MV
and LV lines construction, primary and secondary substations expansion or new construction), thus
causing relevant investments on the distribution grids. An intelligent management approach for EV
charging stations could ensure the respect of the operation limits of the grids in the actual asset. The
same approach should take into account the presence of DG and coordinate the RES energy
production with the new EV charging stations consumption, solving technical problems such as the
reverse power flow. In this way it should be possible to defer or avoid network reinforcements and
development.
The paper shows some results of a wide planning study performed on a real active distribution grid,
including EVs charging stations connected to MV grid (public stations) and LV grid (home stations) in
different EVs spread scenarios, according to European addresses, Italian policies, Enel guidelines and
making a study of the territory where the distribution grid is located. Simulations have been carried
out on the MV and LV grids connected to a HV/MV transformer. The complete analysis has been
based on Power Flow (PF) and Optimal Power Flow (OPF) calculations performed using a MatLab
tool. PF analysis gave the possibility to know the hosting capacity of the distribution grid for EV
charging stations, pointing out if grid reinforcements are required. OPF analysis allowed evaluating
the impact of a smart management approach, taking full advantage of the actual hosting capacity of the
grid, suitably dispatching the EV charging stations. Many objective functions have been tested with
the MatLab tool. Some of the results are reported in the paper for showing the benefits of the smart
management approach in terms of grid reinforcements avoided
Meteorological parameters influence for medium term load forecasting
No full textThe present paper reports a correction algorithm based on meteorological parameters, to apply to a medium-term load forecasting (MTLF) available system. To this aim a correlation study between various meteorological data and electric load of a Municipal Utility has been performed. In particular the analyzed meteorological data concern temperature and humidity gathered along a period of ten years. This correlation analysis made possible to heuristically identify the correction algorithm that is finally tested by evaluating forecasting accuracy of a MTLF system, based on a Artificial Neural Network (ANN), using only electric time series
Proposal of a new procurement strategy of frequency control reserves in power systems. The italian case in the european framework
Full text linkOver the last few years, a strong penetration of Intermittent Renewable Energy Sources (IRES) has been in progress in the Italian power system. In this new framework, the dispatching activity must improve its efficiency to ensure adequacy and security of the national electricity system. European market integration initiatives are making this goal achievable, provided that the coherency of market price signals and reserve procurement at the European level are guaranteed. For this reason, the Italian Transmission System Operator (TSO), Terna, started to investigate the opportunity to align the Italian reserve-procurement approach to the one adopted in most European countries, procuring Replacement Reserve (RR) in dedicated auctions held in advance of the day-ahead market. The aim of this new methodology is to improve the coherency of price signals arising from the integrated European day-ahead market, anticipating potential scarcity conditions, thus helping to keep adequacy standards high. This paper describes the characteristics of a possible new reserve-procurement model based on the European benchmark. Comparative simulations are presented, estimating the impact of the new approach in terms of outcomes and costs of both the energy and ancillary services markets in Italy. The results of this study suggest activation of the reserve auction only in the cases in which the TSO expects a potential risk of simultaneous reserve scarcity across European countries
Iliceto Shield Wire Scheme. An application to HV line in Tanzania
No full textIliceto Shield Wire Scheme (ISWS) is a rural electrification scheme that uses the shield wires of High Voltage (HV) lines as conductors and an earth return to provide power at Medium Voltage (MV) to remote locations at a lower cost than the traditional methods. The present paper includes the main results of an application of this method to a HV line in Tanzania, Chalinze-Hale-Tanga. The application is finalized to find out its technical feasibility. The results show that rural electrification of villages near the Chalinze-Hale-Tanga with the ISWS is technically feasible. It allows also significant economical savings compared to the traditional scheme, mainly because no new tower or pylon need to be erected except for MV spur lines from the HV line to the single village
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