The increasing use of distributed generators, which are mainly based on renewable sources, can create several issues in the operation of the electric grid. The microgrid is being analysed as a ...solution to the integration in the grid of the renewable sources at a high penetration level in a controlled way. The storage systems play a vital role in order to keep the energy and power balance of the microgrid. Due to the technical limitations of the currently available storage systems, it is necessary to use more than one storage technology to satisfy the requirements of the microgrid application. This work validates in simulations and experimentally the use of a Three-Level Neutral Point Clamped converter to control the power flow of a hybrid storage system formed by a SuperCapacitor and a Vanadium Redox Battery. The operation of the system is validated in two case studies in the experimental platform installed in ESTIA. The experimental results prove the validity of the proposed system as well as the designed control algorithm. The good agreement among experimental and simulation results also validates the simulation model, that can therefore be used to analyse the operation of the system in different case studies.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
2.
Status of Virgo Amico, P; Antonucci, F; Aoudia, S ...
Classical and Quantum Gravity,
06/2008, Volume:
25, Issue:
11
Journal Article, Conference Proceeding
Peer reviewed
Open access
The Virgo detector has now finished its first science run; a science mode duty cycle of more than 80% and a 4.5 Mpc horizon distance for binary neutron star inspiral sources were achieved. ...Commissioning breaks were organized during the run which permitted improvement of the sensitivity and the robustness of the interferometer against environmental perturbations like bad weather and earthquakes. The post-run commissioning phase has now started, with the goal of preparing the next upgrade step of the detector, Virgo+.
The status of VIRGO Amico, P; Al-Shourbagy, M; Avino, S ...
Classical and Quantum Gravity,
04/2006, Volume:
23, Issue:
8
Journal Article, Conference Proceeding
Peer reviewed
VIRGO interferometer commissioning started in September 2003. The complete lock of the interferometer was achieved in October 2004 via several steps. The main commissioning activity deals with ...improvements in the interferometer stability and sensitivity. The status of the advancement of VIRGO and the short-term plans are discussed here
Status of Virgo Amico, P; Al-Shourbagy, M; Avino, S ...
Classical and quantum gravity,
09/2005, Volume:
22, Issue:
18
Journal Article, Conference Proceeding
The variable finesse locking technique Amico, P; Al-Shourbagy, M; Avino, S ...
Classical and Quantum Gravity,
04/2006, Volume:
23, Issue:
8
Journal Article, Conference Proceeding
Peer reviewed
Open access
Virgo is a power recycled Michelson interferometer, with 3 km long Fabry–Perot cavities in the arms. The locking of the interferometer has been obtained with an original lock acquisition technique. ...The main idea is to lock the instrument away from its working point. Lock is obtained by misaligning the power recycling mirror and detuning the Michelson from the dark fringe. In this way, a good fraction of light escapes through the antisymmetric port and the power build-up inside the recycling cavity is extremely low. The benefit is that all the degrees of freedom are controlled when they are almost decoupled, and the linewidth of the recycling cavity is large. The interferometer is then adiabatically brought on to the dark fringe. This technique is referred to as variable finesse, since the recycling cavity is considered as a variable finesse Fabry–Perot. This technique has been widely tested and allows us to reach the dark fringe in few minutes, in an essentially deterministic way.
We report on a step-induced morphological modification in Cobalt thin films (from 5 to 90 monolayers (ML)) on Au(1
1
1) substrates studied by grazing incidence X-ray diffraction (GIXD). When the ...cobalt film is deposited on the highly stepped Au(2
3
3) substrate its structure is found to be mainly face centered cubic (FCC) whereas its natural bulk structure is hexagonal close-packed (HCP). Relaxation and stacking fault probability have been determined using a simple diffraction model which fits all the GIXD data. A vicinal Co interface including this stacking fault probability and a small rotation of the Co(1
1
1) planes with respect to the Au(1
1
1) planes is proposed which is in exact registry with the Au vicinal surface.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
8.
The Global Control of the Virgo experiment Arnaud, Nicolas; Arnault, Christian; Barsuglia, Matteo ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2005, Volume:
550, Issue:
1
Journal Article
Peer reviewed
In order to detect gravitational waves, the kilometric interferometer Virgo needs an active control of the positions of the suspended optical components, keeping the detector at its working point. ...The constraints are about
10
-
10
m
RMS for the longitudinal control (“Locking”) and
10
-
9
rad
RMS for the angular degrees of freedom (“Alignment”). A dedicated hardware and software named Global Control is in charge of the Locking and the Alignment loops for the Virgo experiment. This system has been designed to match the synchronization constraint and provide a flexible tool in order to easily integrate the various algorithms needed for the control of Virgo. This paper presents the technical requirements to be fulfilled by the Global Control. Then, the dedicated hardware is described and the overall architecture of the Global Control is shown.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
This paper presents a complete description of Virgo, the French-Italian gravitational wave detector. The detector, built at Cascina, near Pisa (Italy), is a very large Michelson interferometer, with ...3 km-long arms. In this paper, following a presentation of the physics requirements, leading to the specifications for the construction of the detector, a detailed description of all its different elements is given. These include civil engineering infrastructures, a huge ultra-high vacuum (UHV) chamber (about 6000 cubic metres), all of the optical components, including high quality mirrors and their seismic isolating suspensions, all of the electronics required to control the interferometer and for signal detection. The expected performances of these different elements are given, leading to an overall sensitivity curve as a function of the incoming gravitational wave frequency. This description represents the detector as built and used in the first data-taking runs. Improvements in different parts have been and continue to be performed, leading to better sensitivities. These will be detailed in a forthcoming paper.
Properties of seismic noise at the Virgo site Acernese, F; Amico, P; Arnaud, N ...
Classical and Quantum Gravity,
03/2004, Volume:
21, Issue:
5
Journal Article, Conference Proceeding
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