38 results on '"Novello, Luca"'
Search Results
2. Development of supervisory control system for magnet power supplies in JT-60SA
- Author
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Hatakeyama, Shoichi, Shimada, Katsuhiro, Yamauchi, Kunihito, Matsukawa, Makoto, Moriyama, Shinichi, Novello, Luca, Frello, Giampaolo, Baulaigue, Olivier, Gaio, Elena, Maistrello, Alberto, Ferro, Alberto, Lampasi, Alessandro, and Zito, Pietro
- Published
- 2019
- Full Text
- View/download PDF
3. Final tests of the four switching network units procured by the European Union for JT-60SA
- Author
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Lampasi, Alessandro, Zito, Pietro, Novello, Luca, Matsukawa, Makoto, Shimada, Katsuhiro, Burini, Filippo, Taddia, Giuseppe, and Tenconi, Sandro
- Published
- 2017
- Full Text
- View/download PDF
4. First Switching Network Unit for the JT-60SA superconducting Central Solenoid
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Lampasi, Alessandro, Zito, Pietro, Coletti, Alberto, Novello, Luca, Matsukawa, Makoto, Shimada, Katsuhiro, Burini, Filippo, Fone, Yannick Kuate, Taddia, Giuseppe, and Tenconi, Sandro
- Published
- 2015
- Full Text
- View/download PDF
5. Reference design of the power supply system for the resistive-wall-mode control in JT-60SA
- Author
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Ferro, Alberto, Gaio, Elena, Novello, Luca, Matsukawa, Makoto, Shimada, Katsuhiro, Kawamata, Yoichi, and Takechi, Manabu
- Published
- 2015
- Full Text
- View/download PDF
6. Analyses of the impact of connections’ layout on the coil transient voltage at the Quench Protection Circuit intervention in JT-60SA
- Author
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Maistrello, Alberto, Gaio, Elena, Novello, Luca, Matsukawa, Makoto, and Yamauchi, Kunihito
- Published
- 2015
- Full Text
- View/download PDF
7. Overview of the new Magnet Power Supply Systems of JT-60SA procured by EU
- Author
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Novello, Luca, Baulaigue, Olivier, Coletti, Alberto, Dumas, Nicolas, Ferro, Alberto, Gaio, Elena, Lampasi, Alessandro, Maistrello, Alberto, Matsukawa, Makoto, Shimada, Katsuhiro, Yamauchi, Kunihito, and Zito, Pietro
- Published
- 2015
- Full Text
- View/download PDF
8. Enhancement of the power supply systems in RFX-mod towards 2 MA plasma current
- Author
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Novello, Luca, Zamengo, Andrea, Ferro, Alberto, Zanotto, Loris, Barp, Marco, Cavazzana, Roberto, Finotti, Claudio, Recchia, Mauro, and Gaio, Elena
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- 2011
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- View/download PDF
9. Conceptual design of the quench protection circuits for the JT-60SA superconducting magnets
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Gaio, Elena, Novello, Luca, Piovan, Roberto, Shimada, Katsuhiro, Terakado, Tsunehisa, Kurihara, Kenichi, and Matsukawa, Makoto
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- 2009
- Full Text
- View/download PDF
10. Installation, Commissioning and Tests of Four Fast Switching Units up to 20 kA for the JT-60SA Nuclear Fusion Experiment
- Author
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Lampasi, Alessandro, Burini, Filippo, Taddia, Giuseppe, Tenconi, Sandro, Shimada, Katsuhiro, Matsukawa, Makoto, Novello, Luca, Jokinen, Antti, and Zito, Pietro
- Abstract
The tokamak JT-60SA is presently under construction in Naka (Japan) as a joint collaboration between Europe and Japan on the field of nuclear fusion research, in the framework of the Broader Approach Agreement. According to the international agreement, the different systems composing JT-60SA are supplied by European and Japanese institutions. In particular the four Switching Network Units (SNU) for the Central Solenoid (CS) of JT-60SA have been procured by ENEA. The design, manufacturing and factory test activities have been completed in 2016, and after the delivery in Naka the SNU have been installed and successfully commissioned in 2017. After an overview on the main technical characteristics of the SNU and the key aspects of their design, this paper describes the activities performed on-site, highlighting the results obtained during the final acceptance tests and comparing them with the design simulation and the factory test results.
- Published
- 2018
11. Design and Testing of Crowbar Protection System for the JT- 60SA Superconducting Magnet Power Supplies
- Author
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Zito, Pietro., Lampasi, Alessandro., O.Baulaigue, S.Gharafi, Novello, Luca, Matsukawa, Makoto, F.Fasce, M.Portesine, A.Dorronsoro, D.Vian, K.Celaya, B.Eikelboom, and Shimada, Katsuhiro
- Abstract
JT-60SA is a Superconducting Tokamak in the framework of the Broader Approach Agreement (BAA) between Europe and Japan. For this International Project, both the Italian National Agency for New Technology, Energy and Sustainable Economic Development (ENEA) and the French Alternative Energies and Comissariat à l’Energie Atomique et aux Energies alternatives (CEA) have to provide overall twelve AC/DC pulse poloidal superconducting magnet power supplies (almost all rated for ±20 kA and ±1 kV). Each of them is equipped with a crowbar protection system. The crowbar system’s first function is to carry the current that is flowing through the superconducting coils and protects the AC/DC power converter from over-voltages, internal/external severe faults and in case of earthquakes. The current capability type test of crowbar system required a maximum peak current of ±26 kA and a maximum specific energy I2t = 4,6 GA2s for TF SCMPS. Finally the crowbar system and DC bus-bars were subjected to seismic tests in laboratory.
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- 2018
12. Correlation between induction of DNA fragmentation in lung cells from rats and humans and carcinogenic activity
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Robbiano, Luigi, Baroni, Debora, Novello, Luca, and Brambilla, Giovanni
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- 2006
- Full Text
- View/download PDF
13. Progress in Development and Fabrication of the JT-60SA ECH/CD System
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Kobayashi, Takayuki, Moriyama, Shinichi, Takahashi, Koji, Kajiwara, Ken, Oda, Yasuhisa, Ikeda, Ryosuke, Isayama, Akihiko, Novello, Luca, Sawahata, Masayuki, Terakado, Masayuki, Hiranai, Shinichi, Sato, Fumiaki, Wada, Kenji, Hinata, Jun, and Yokokura, Kenji
- Abstract
Development of the ECH/CD system for JT-60SA has been progressed. (i) A full length (~7 m) mock-up of the mirror steering structure of the launcher has been successfully tested in vacuum. The required life without maintenance, which is 105 cycles for the poloidal steering range of 60° and 104 cycles for toroidal beam steering range of 30°, has been achieved. A newly introduced solid lubricant enabled the smooth movement of the steering shaft. (ii) The temperature rise distribution of aluminum waveguides has been measured at high-power of 0.5 MW. It is in the range from 0.2 to 1.2 °C per 1 MJ transmission and acceptable for 1 MW/100 s transmission required in JT-60SA. (iii) The preparation of the JT-60SA ECH/CD system toward first plasma experiment is smoothly progressing by the above results and the successful gyrotron development., 27th IAEA Fusion Energy Conference (FEC 2018)
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- 2018
14. Toward the completion of the Power Supply system for Resistive Wall Modes control in JT-60SA
- Author
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Gaio, Elena, Ferro, Alberto, Gasparini, Ferdinando, Piovan, Roberto, Novello, Luca, Frello, Giampaolo, Hatakeyama, Shoichi, and Shimada, Katsuhiro
- Abstract
The Power Supply system for Resistive Wall Modes (RWM) control in the JT-60SA experiment is an Italian in-kind contribution to JT-60SA within the Broader Approach Agreement. A very efficient control of RWM is necessary to access plasma currents with high βN values (3-5) sustained for a hundred seconds, as foreseen in the JT-60SA research plan. The development of the whole RWM control system (coils, power supplies and control) went through several steps of optimization; the final coil configuration is made of three toroidal rings of six coils placed on the plasma side of the a stabilizing plate, inside the vacuum vessel; the coils are individually fed by dedicated power amplifiers, controlled in real time. A key aspect highlighted by the physics studies was the need of a very fast reaction of the control system to prevent an excessive growth of the plasma instabilities and to limit the power required for their control. The main requirements for the power amplifiers were a peak current of 300 A, output voltage of 240 V, bandwidth of 3 kHz and a latency shorter than 50 μs. The satisfaction of so fast dynamics was addressed via an R&D program which led to an innovative design solution adopting hybrid Silicon-Silicon Carbide (Si-SiC) semiconductor for the power amplifiers and to the development of a new sophisticated inverter on-board control. The schedule of the procurement was finalized in 2015 and was articulated in a relatively longer phase, for the detailed design, prototype development and testing, with respect to the manufacturing due to the high level of innovation. The delivery to Japan is expected in September 2018. An overview of the main phases of the development and realization of this advanced system, the first in fusion experiments adopting SiC semiconductors, will be presented., 30th edition of the Symposium on Fusion Technology (SOFT 2018)
- Published
- 2018
15. Development of Supervisory Control System for Magnet Power Supplies in JT-60SA
- Author
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Hatakeyama, Shoichi, Shimada, Katsuhiro, Yamauchi, Kunihito, Matsukawa, Makoto, Moriyama, Shinichi, Baulaigue, Olivier, Gaio, Elena, Maistrello, Alberto, Ferro, Alberto, Novello, Luca, Frello, Giampaolo, Lampasi, Alessandro, and Zito, Pietro
- Abstract
Magnet power supply (PS) system of JT-60SA is being implemented within the Broader Approach Agreement aiming to achieve first plasma in 2020. The system consists of several components such as DC power supply, switching network unit, quench protection circuit and motor-generator. All the components have their own internal controller (LCC) for stand-alone operation so the individual commissioning are in progress and almost completed. The next step scheduled is a combination test with all components in which supervisory control system manage LCCs remotely. The supervisory system covers the following roles: 1) machine status monitoring; 2) discharge sequence management; 3) real-time reference waveforms management; 4) data acquisition; 5) machine protection; 6) human safety. The supervisory system consists of several subsystems; PS supervising computer (PS-SC), PS programmable logic controller (PS-PLC), PS internal protection system(PS-IPS) and PS safety interlock system (PS-SIS). PS-SC covers the primary roles in 1) – 4) which is built on CompactPCIs with real-time OS INtime. PS-SC and LCCs are linked through a Reflective Memory (RM) network to share common data in real-time (4 kHz). PS-SC is also linked to the upstream JT-60SA supervisory control system (SCSDAS) via another RM network as an interface for the power supply internal control systems. During discharge sequence, PS-SC also manages motor-generator speed, AC circuit breakers OPEN/CLOSE status with a controller PS-PLC and magnets current according to request from SCSDAS. PS-IPS covers the function of 5) which is implemented on FPGA. PS-IPS is connected to LCCs via fiber optical and hard-wired signals. In case of emergency events such as magnet quench and earth quake, PS-IPS commands to shut down the magnets currents immediately. PS-SIS plays the role in 6) such as status and permission of fence OPEN/CLOSE and grounding switch for maintenance. In this presentation, overview and development of the supervisory system are described., 30th edition of the Symposium on Fusion Technology (SOFT 2018)
- Published
- 2018
16. Type Tests of JT-60SA Central Solenoid / Equilibrium Field (CS/EF) Super-Conducting Magnet Power Supplies
- Author
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Zito, Pietro, Lampasi, Alessandro, Novello, Luca, Matsukawa, Makoto, Shimada, Katsuhiro, Hatakeyama, Shoichi, Portesine, Marco, Dorronsoro, Ander, Vian, Dionisio, and Celaya, Koldo
- Abstract
JT-60SA is a superconducting tokamak in the framework of the broader approach agreement between Europe and Japan. For this international project among its various procurements, the Italian National Agency for new technology energy and sustainable economic development (ENEA) is providing four ac/dc converters for the central solenoid (CS) superconducting magnets, two ac/dc converters for the equilibrium field (EF) superconducting magnets, and two ac/dc converters for the fast plasma position control coils (FPPCC). Furthermore, ENEA is also providing six converter transformers of which four are of the dry type for FPPCC power supplies (PSs) and two of oil type for CS PSs. CS/EF PSs feed poloidal superconducting magnets of JT-60SA, whose purpose is the generation of strong magnetic fields able to induce and confine the plasma current in a prefixed geometrical configuration. The control system of CS/EF PSs has to be able to reproduce in real-time a reference current or voltage profile, known as “scenario” and these are particularly critical in these systems for the high currents required and for the high magnetic energy stored in the superconducting magnets. All performed type tests, carried out in accordance to the IEC60146 Standards, pointed toward a good dynamic behavior of the control system both for forward and for reverse rectifier bridges, assuring the smooth transitions between different operating modes: single mode, circulating current mode and dual mode. This is the focus of this paper.
- Published
- 2018
17. Towards the completion of the Power Supply system for Resistive Wall Modes control in JT-60SA
- Author
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Gaio Elena, Ferro Alberto, Gasparini Ferdinando, Novello Luca, Frello Giampaolo, Matsukawa Makoto, Hatakeyama Shoichi, Shimada Katsuhiro, and Piovan Roberto
- Subjects
Magnet Power Supplies ,JT-60SA ,RWM ,Resistive Wall Modes - Abstract
The Power Supply system for Resistive Wall Modes (RWM) control in the JT-60SA experiment is an Italian in-kind contribution to JT-60SA within the Broader Approach Agreement. A very efficient control of RWM is necessary to access plasma currents with high ?N values (3-5) sustained for a hundred seconds, as foreseen in the JT-60SA research plan. The development of the whole RWM control system (coils, power supplies and control) went through several steps of optimization; the Ynal coil conYguration consists in three toroidal rings of six coils placed on the plasma side of the stabilizing plate, inside the vacuum vessel; the coils are individually fed by dedicated power ampliYers, controlled in real time. A key aspect highlighted by the physics studies was the need of a very fast reaction of the control system to prevent an excessive growth of the plasma instabilities and to limit the power required for their control. The main requirements for the power ampliYers were a peak current of 300 A, output voltage of 240 V, bandwidth of 3 kHz and a latency shorter than 50 ?s. The fulYllment of such a fast dynamics was addressed via an R&D program which led to an innovative design solution adopting hybrid Silicon-Silicon Carbide (Si-SiC) semiconductor for the power ampliYers and to the development of a new sophisticated inverter on-board control. The schedule of the procurement was Ynalized in 2015 and was articulated in a relatively longer phase, for the detailed design, prototype development and testing, in comparison with the manufacturing phase, due to the high level of innovation. The delivery to Japan is expected in September 2018. An overview of the main phases of the development and realization of this advanced system, the Yrst in fusion experiments adopting SiC semiconductors, will be presented.
- Published
- 2018
18. Development of Supervisory Control System for Magnet Power Supplies in JT-60SA
- Author
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Hatakeyama Shoichi, Shimada Katsuhiro, Yamauchi Kunihito, Matsukawa Makoto, Baulaigue Olivier, Gaio Elena, Maistrello Alberto, Ferro Alberto, Novello Luca, Frello Giampaolo, Lampasi Alessandro, and Zito Pietro
- Subjects
Magnet Power Supplies ,JT-60SA - Abstract
Magnet power supply (PS) system of JT-60SA is being implemented within the Broader Approach Agreement aiming to achieve Vrst plasma in 2020. The system consists of several components such as DC power supply, switching network unit, quench protection circuit and motor-generator. All the components have their own internal controller (LCC) for stand-alone operation so the individual commissioning are in progress and almost completed. The next step scheduled is a combination test with all components in which supervisory control system manage LCCs remotely. The supervisory system covers the following roles: 1) machine status monitoring; 2) discharge sequence management; 3) real-time reference waveforms management; 4) data acquisition; 5) machine protection; 6) human safety. The supervisory system consists of several subsystems; PS supervising computer (PS-SC), PS programmable logic controller (PSPLC), PS internal protection system(PS-IPS) and PS safety interlock system (PS-SIS). PS-SC covers the primary roles in 1) - 4) which is built on CompactPCIs with real-time OS INtime. PS-SC and LCCs are linked through a Re_ective Memory (RM) network to share common data in real-time (4 kHz). PS-SC is also linked to the upstream JT-60SA supervisory control system (SCSDAS) via another RM network as an interface for the power supply internal control systems. During discharge sequence, PS-SC also manages motor-generator speed, AC circuit breakers OPEN/CLOSE status with a controller PS-PLC and magnets current according to request from SCSDAS. PS-IPS covers the function of 5) which is implemented on FPGA. PS-IPS is connected to LCCs via Vber optical and hard-wired signals. In case of emergency events such as magnet quench and earth quake, PS-IPS commands to shut down the magnets currents immediately. PS-SIS plays the role in 6) such as status and permission of fence OPEN/CLOSE and grounding switch for maintenance. In this presentation, overview and development of the supervisory system are described.
- Published
- 2018
19. Installation, Commissioning and Acceptance Tests of the Switching Network Units for the Central Solenoids of JT-60SA
- Author
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Burini, Filippo, Jokinen, Antti, Novello, Luca, Shimada, Katsuhiro, and Matsukawa, Makoto
- Abstract
JT-60SA is an international tokamak being built in Naka (Japan) as a joint collaboration between Europe and Japan for the applied researches on the use of nuclear fusion as a new energy source. The procurement of the different systems composing JT-60SA is managed as in-kind contribution shared between European and Japanese institutions. The procurement of the Switching Network Units (SNUs) for the Central Solenoids (CS) is supported by Europe. After a four-year design and manufacturing in Europe, the JT-60SA CS SNUs and the related components were delivered to Japan in October 2016. This presentation describes the activities for the on-site installation, commissioning and tests of this procurement., 17th International Conference on Environment and Electrical Engineering (EEEIC2017)
- Published
- 2017
20. Type Tests of JT-60SA Central Solenoid / Equilibrium Field (CS/EF) Super-Conducting Magnet Power Supplies
- Author
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Zito, Pietro, Lampasi, Alessandro, Novello, Luca, Hatakeyama, Shoichi, Matsukawa, Makoto, Shimada, Katsuhiro, Portesine, Marco, Dorronsoro, Ander, Vian, Dionisio, and Celaya, Koldo
- Abstract
JT-60SA is a Superconducting Tokamak in the framework of the Broader Approach Agreement between Europe and Japan. For this International Project among its various procurements, the Italian National Agency for New Technology Energy and Sustainable Economic Development (ENEA) is providing: four AC/DC converters for the central solenoid superconducting magnets (CS1, CS2, CS3 and CS4 PSs rated ±20 kA and ±1 kV); two AC/DC converters for the Equilibrium Field superconducting magnets (EF1 and EF6 PSs rated in the range +10 kA -20 kA and ±1 kV); and two AC/DC converters Fast Plasma Position Control Coils (rated ±5 kA and ±1 kV). Furthermore, ENEA is also providing six converter transformers of which: four dry type for FPPCC PSs and two oil type for CS PSs. These systems, being procured by ENEA through a contract signed in August 2013 with Industrial Suppliers (Poseico and Jema in Join-Venture), have been already constructed and they are in advanced testing phase. The basic devices of a CS/EF PS consist in: a thyristors rectifier or base PS, a converter transformer, a crowbar (to protect by over-voltages and/or over-currents); whereas the load of the CS/EF PS is a Super-Conducting Magnet, whose purpose is the generation of strong magnetic fields able to induce and confine the plasma current in a prefixed geometrical configuration. This requires that the control system of CS/EF PSs is able to comply with a reference current profile, known as “scenario”. The scenarios are particularly critical in these systems for the high currents required and hence for the high magnetic energy stored. The installed total electric power in JT-60SA is about 400 MVA, with a peak of reactive power equal to 330 MVAR and an energy consumption up to 1.5 GJ. The main characteristics of CS/EF base thyristor rectifier are: 4-quadrant AC/DC converter 12-pulses with circulating current in back-to-back configuration, with a DC current of ±20 kA, a DC voltage of 1 kV and an accuracy of ±1%. The design phase was completed in 2015, the construction of all EF/CS PSs was completed in 2016 whereas all PSs were tested in 2016 except EF PSs that are currently ongoing. All performed type tests were carried out both in closed loop feedback current control and in open loop feed forward voltage control and in accordance to the IEC60146 Standards. The electric load used for these tests the consists of three inductances connected in series, whole resulting values of 3.3mH and 3mΩ. The measure electric scheme is fed by the 30kV electric power grid and by an autotransformer, that offers the possibility to increase or decrease the voltage that is going to the converter transformers, that power the EF/CS PS. These tests, made at full current, pointed out a good dynamic behaviour of the control system both for forward and for reverse rectifier bridges, assuring the smooth transitions between different operating modes: single mode, circulating current mode and dual mode. This is the focus of the paper. The complete systems will be delivered to Japan by 2017., 27th IEEE Symposium on Fusion Engineering (SOFE-2017)
- Published
- 2017
21. Final tests of the four switching network units procured by the European Union for JT-60SA
- Author
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Lampasi, Alessandro., Zito, Pietro, Novello, Luca, Shimada, Katsuhiro, and Matsukawa, Makoto
- Abstract
Switching Network Units (SNUs) are inserted in the power supply circuits of modern tokamaks for plasma initiation. In the framework of the “Broader Approach” agreement, the four SNUs for the superconducting modules of the JT-60SA Central Solenoid will be procured by European Union through the Italian Agency ENEA.The design is based on the synchronized operations of a light electromechanical contactor and of a static switch to combine the benefits of both devices. The adopted solutions could be extended to many fusion and industrial applications. A SNU was able to divert to a breakdown resistance (from 0.25 Ω to 3.75 Ω) currents up to 20 kA, producing a voltage drop up to 5 kV in less than 100 µs with a transient overvoltage limited to about 200 V.The tests showed good performance repeatability for all the SNUs. The accuracy of all the breakdown resistors was well within ±2%. Specific tests showed that they could dissipate much more than 360 MJ., 29th Symposium on Fusion Technology (SOFT2016)
- Published
- 2016
22. Final Design of SiC-based Power Supply system for Resistive-Wall-Mode control in JT-60SA
- Author
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Gaio Elena, Ferro Alberto, Novello Luca, Matsukawa Makoto, and Shimada Katsuhiro
- Subjects
Resistive-Wall-Modes ,SiC-based Power Supply system ,Resistive-Wall-Mode control ,JT-60SA ,RWM - Abstract
Efficient control of Resistive-Wall-Modes (RWM) is mandatory in JT-60SA, the satellite tokamak under construction in Naka (Japan), since one of its main objectives is to reach steady-state high-beta plasmas. The RWM control system is based on a set of 18 in-vessel sector coils, placed on the plasma side of a conductive wall and independently fed by a dedicated fast power supply system (RWM-PS). This is the first PS system for fast control of plasma instabilities in fusion experiments adopting SiC semiconductors. The paper will give an overview of the whole final design with particular emphasis on the newest features and on the interface issues for an efficient integration with the JT-60SA power and control systems., 29th Symposium on Fusion Technology (SOFT2016)
- Published
- 2016
23. Design and Testing of Crowbar Protection System for the JT- 60SA Superconducting Magnet Power Supplies
- Author
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Zito, Pietro., Lampasi, Alessandro., Novello, Luca, Shimada, Katsuhiro, and Matsukawa, Makoto
- Abstract
JT-60SA is a Superconducting Tokamak in the framework of the Broader Approach Agreement (BAA) between Europe and Japan. For this International Project, both the Italian National Agency for New Technology, Energy and Sustainable Economic Development (ENEA) and the French Alternative Energies and Comissariat à l’Energie Atomique et aux Energies alternatives (CEA) have to provide overall twelve AC/DC pulse poloidal superconducting magnet power supplies (almost all rated for ±20 kA and ±1 kV). Each of them is equipped with a crowbar protection system. The crowbar system’s first function is to carry the current that is flowing through the superconducting coils and protects the AC/DC power converter from over-voltages, internal/external severe faults and in case of earthquakes. The current capability type test of crowbar system required a maximum peak current of ±26 kA and a maximum specific energy I2t = 4,6 GA2s for TF SCMPS. Finally the crowbar system and DC bus-bars were subjected to seismic tests in laboratory., 29th Symposium on Fusion Technology (SOFT2016)
- Published
- 2016
24. Type Tests of JT-60SA Central Solenoid/Equilibrium Field Superconducting Magnet Power Supplies.
- Author
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Zito, Pietro, Lampasi, Alessandro, Novello, Luca, Matsukawa, Makoto, Shimada, Katsuhiro, Hatakeyama, S., Portesine, Marco, Dorronsoro, Ander, Vian, Dionisio, and Celaya, Koldo
- Subjects
TOKAMAKS testing ,SUPERCONDUCTING device testing ,SUPERCONDUCTING magnets testing ,POWER distribution in nuclear reactors ,AC DC transformers ,THYRISTORS ,MAGNETIC field measurements - Abstract
JT-60SA is a superconducting tokamak in the framework of the broader approach agreement between Europe and Japan. For this international project among its various procurements, the Italian National Agency for new technology energy and sustainable economic development (ENEA) is providing four ac/dc converters for the central solenoid (CS) superconducting magnets, two ac/dc converters for the equilibrium field (EF) superconducting magnets, and two ac/dc converters for the fast plasma position control coils (FPPCC). Furthermore, ENEA is also providing six converter transformers of which four are of the dry type for FPPCC power supplies (PSs) and two of oil type for CS PSs. CS/EF PSs feed poloidal superconducting magnets of JT-60SA, whose purpose is the generation of strong magnetic fields able to induce and confine the plasma current in a prefixed geometrical configuration. The control system of CS/EF PSs has to be able to reproduce in real-time a reference current or voltage profile, known as “scenario” and these are particularly critical in these systems for the high currents required and for the high magnetic energy stored in the superconducting magnets. All performed type tests, carried out in accordance to the IEC60146 Standards, pointed toward a good dynamic behavior of the control system both for forward and for reverse rectifier bridges, assuring the smooth transitions between different operating modes: single mode, circulating current mode and dual mode. This is the focus of this paper. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
25. Design and Manufacturing of the SiC-Based Power Supply System for Resistive-Wall-Mode Control in JT-60SA.
- Author
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Ferro, Alberto, Gasparini, Ferdinando, Gaio, Elena, Tomasini, Matteo, Milani, Paolo, Massarelli, Emanuele, Novello, Luca, Matsukawa, Makoto, Hatakeyama, Shoichi, and Shimada, Katsuhiro
- Subjects
FUSION reactor walls ,NUCLEAR reactors ,INSULATED gate bipolar transistors ,PLASMA stability ,SILICON carbide ,PULSE width modulation transformers ,POWER transformers ,TOKAMAKS -- Design & construction ,EQUIPMENT & supplies - Abstract
In JT-60SA, the control of resistive-wall-mode (RWM) instabilities will also be realized with a dedicated active control system based on 18 in-vessel sector coils. Each coil will be fed independently by a dedicated fast inverter. Due to the outstanding dynamic performance required, new insulated-gate bipolar transistor modules based on silicon carbide (SiC) have been adopted. Being capable to switch at 30 kHz, these components, together with a very fast control system, allow reaching the required high dynamic performance with the simple and compact H-bridge topology. The RWM-PS will be the first power supply system for fast control of plasma instabilities in fusion experiments adopting SiC semiconductors. This paper gives an overview of the final design of the RWM-PS, with particular emphasis on its special features and the solutions implemented to satisfy the critical requirements. The issues related with the high switching frequency and the peculiar nature of the load will be treated in detail. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
26. Broadband Electromagnetic Modeling of the Superconducting Toroidal Field Magnets of JT-60SA: Transient Simulation and Fault Detectability.
- Author
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Bruno, Alessandro, Cardella, Antonino, Novello, Luca, and Tomarchio, Valerio
- Subjects
TOROIDAL magnetic circuits ,PLASMA confinement ,TRANSIENT conditions (Physics) ,MAGNETIC fields ,MAGNETIC resonance - Abstract
The superconducting toroidal field (TF) magnets of JT-60SA are designed to conduct a 25.7 kA current to generate a steady magnetic field for plasma confinement. In case of loss of their superconductive status, a fast discharge of the current is operated and the TF magnets are subjected to electromagnetic transient phenomena in a range of frequencies up to several tens of kHz. The TF coils show an involved frequency-dependent behavior as a consequence of eddy currents induced in the casing, stray capacitances, as well as electrical skin-effect in the jacket enclosing the strands; therefore, electrical models derived considering the coil characteristics at a single frequency may not be suitable to perform reliable analyses of the fast discharge event. A broadband electromagnetic model was generated and validated against experimental data. Such a model can reproduce with sufficient accuracy the behavior of the TF magnets in the frequency range of interest. This model was employed to simulate the transient of the voltage distribution inside the coils during a fast discharge and to evaluate the maximum voltage difference between adjacent turns. The model was also employed to make predictions about the detectability of internal short-circuit in a coil by means of impedance spectrum measurements. It was possible to conclude that the highest sensitivity to short circuits can be achieved looking for impedance variations in proximity of the antiresonant frequency. [ABSTRACT FROM PUBLISHER]
- Published
- 2017
- Full Text
- View/download PDF
27. Advancement on the procurement of Power Supply systems for JT-60SA.
- Author
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Novello, Luca, Coletti, Alberto, Baulaigue, Olivier, Dumas, Nicolas, Ferro, Alberto, Gaio, Elena, Maistrello, Alberto, Lampasi, Alessandro, Zito, Pietro, Matsukawa, Makoto, Shimada, Katsuhiro, and Yamauchi, Kunihito
- Published
- 2015
- Full Text
- View/download PDF
28. Type tests of JT-60SA Fast Plasma Position Control Coil (FPPCC) power supplies.
- Author
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Zito, Pietro, Lampasi, Alessandro, Novello, Luca, Matsukawa, Makoto, Shimada, Katsuhiro, Portesine, Marco, Fasce, Fioravante, Cinarelli, Danilo, Dorronsoro, Ander, and Vian, Dionisio
- Published
- 2015
- Full Text
- View/download PDF
29. A 72 kVA very fast four-quadrant converter based on hybrid Si-SiC IGBTs.
- Author
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Ferro, Alberto, Gaio, Elena, Tomasini, Matteo, Milani, Paolo, Massarelli, Emanuele, Matsukawa, Makoto, and Novello, Luca
- Published
- 2015
- Full Text
- View/download PDF
30. Power Amplifiers Based on SiC Technology for MHD Mode Control in Fusion Experiments.
- Author
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Gaio, Elena, Ferro, Alberto, Novello, Luca, and Matsukawa, Makoto
- Subjects
POWER amplifiers ,MAGNETOHYDRODYNAMICS ,POWER resources ,FUSION (Phase transformation) ,TOKAMAKS ,ELECTRIC potential - Abstract
The effective control of magnetohydrodynamic instabilities in fusion experiments by means of actively controlled coils calls for challenging dynamic requirements to the relevant power supply (PS) systems. The first part of this paper gives an overview on typical requirements and technological solutions adopted in some present fusion experiments. Then, the advantages of SiC devices with respect to the Si ones are described in this paper, including lower switching losses, higher switching speed, higher operating junction temperature, and higher voltage capability. As an application example, this paper reports on the case of the PS system for resistive wall mode control in the JT-60SA satellite tokamak, where analyses showed the difficulty of satisfying the demanding requirements in terms of high current bandwidth (3 kHz) and short latency ( <50~\mu \texts ) with a simple H-bridge topology adopting standard IGBT. On the contrary, the use of Si–SiC IGBT with the same topology can allow meeting the specifications, as demonstrated by the development and test of such a power amplifier, rated for $300~A_{{\mathrm{pk}}}$ and 240 V. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
31. Successful primary staple-repair of thoracic oesophagus after delayed presentation of a spontaneous perforation
- Author
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Leoncini, Giacomo, Novello, Luca, Denegri, Andrea, Morelli, Lucia, and Ratto, Giovanni B.
- Published
- 2015
- Full Text
- View/download PDF
32. Review of the RFX-Mod AC/DC Conversion System and Possible Improvements for New Plasma Scenarios.
- Author
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Ferro, Alberto, Framarin, Junior Jader, Novello, Luca, Zamengo, Andrea, Zanotto, Loris, and Gaio, Elena
- Subjects
ELECTRIC current converters ,CONVERTERS (Electronics) ,ALTERNATING currents ,DIRECT currents ,SIMULATION methods & models - Abstract
This paper first recalls the main characteristics, design criteria, and strong points of the ac/dc conversion system of RFX-mod. Then, after having described some innovative experimental scenarios and performance improvements which have been devised, the corresponding impact on the ac/dc conversion system and the compatibility with the present design are discussed. Some possible upgrades are identified and the pros and cons are evaluated, also through dedicated simulations. [ABSTRACT FROM PUBLISHER]
- Published
- 2014
- Full Text
- View/download PDF
33. Final Design of the Quench Protection Circuits for the JT-60SA Superconducting Magnets.
- Author
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Gaio, Elena, Maistrello, Alberto, Coffetti, Alberto, Gargano, Teresa, Perna, Mauro, Novello, Luca, Coletti, Alberto, Matsukawa, Makoto, and Yamauchi, Kunihito
- Subjects
DIRECT currents ,TOKAMAKS ,HYBRID integrated circuits ,CONCEPTUAL design ,ELECTRIC potential - Abstract
This paper describes the detailed design of the quench protection circuits (QPCs) for the superconducting toroidal field (TF) and poloidal field (PF) magnets of the satellite tokamak JT-60SA, which will be installed in Naka, Japan. The nominal currents to be interrupted and the maximum reapplied voltages are 25.7 kA and 2.8 kV for the TF QPCs and 20 kA and 5 kV for the PF QPCs. The innovative solution proposed in the QPC design is based on a hybrid circuit breaker (CB) composed of a mechanical bypass switch for conducting the continuous current, in parallel to a static CB for current interruption. The main choices of the final design are presented and discussed, either to confirm or to update and complete the study performed at the conceptual design level. [ABSTRACT FROM PUBLISHER]
- Published
- 2012
- Full Text
- View/download PDF
34. Development and Testing of a 10-kA Hybrid Mechanical–Static DC Circuit Breaker.
- Author
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Novello, Luca, Baldo, Fabio, Ferro, Alberto, Maistrello, Alberto, and Gaio, Elena
- Subjects
- *
THYRISTORS , *TESTING , *ELECTRIC circuit breakers , *PROTOTYPES , *SUPERCONDUCTING magnets , *COMMUTATION (Electricity) , *ELECTRIC resistors - Abstract
This paper presents the development and testing of the prototype of a hybrid mechanical–static dc circuit breaker (CB) for quench protection of superconducting magnets based on a mechanical switch paralleled to a static CB. In normal operation, the mechanical switch is closed and it handles the continuous flow of dc current, minimizing the on-state losses. In case of intervention, the mechanical switch opens, commutating the current into the static CB that quickly interrupts and transfers the current into a discharge resistor, withstanding the reapplied voltage. This paper was carried out to face and solve some issues of this design solution being not available in the literature examples of similar applications rated for significant power levels. The operation of the hybrid CB has been successfully tested up to a current of 10 kA with a recovery voltage of about 1 kV. Special tests have been dedicated to characterize the reliability and the repeatability of the current commutation from the mechanical switch to the static CB and to characterize the arc voltage under different conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
35. Feasibility Study of a Hybrid Mechanical-Static DC Circuit Breaker for Superconducting Magnet Protection.
- Author
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Novello, Luca, Gaio, Elena, and Piovan, Roberto
- Subjects
- *
ELECTRIC switchgear , *FEASIBILITY studies , *SUPERCONDUCTING magnets , *SUPERCONDUCTORS , *THYRISTORS , *ELECTRIC currents , *ELECTRIC potential - Abstract
This paper describes the feasibility studies of a hybrid dc circuit breaker (CB) for quench protection of superconducting magnets rated for current up to some tens of kiloamperes (kA) and voltage of several kilovolts (kV). The proposed scheme is based on a mechanical switch paralleled to a fully controlled static CB; integrated gate commutated thyristors (IGCTs) were selected. In normal operation, the mechanical switch handles the continuous flow of dc current minimizing the on-state losses. When protection against quench is requested, the current is diverted into the static breaker that quickly interrupts the current, withstanding the reapplied voltage of several kV. The reliable turn-ON of several IGCTs in parallel with low voltage applied between anode and cathode is an issue to be assessed to confirm the feasibility of this design solution. The paper highlights that the components commonly used as snubber or protection circuit can guarantee the turn-ON of all the devices in parallel and that the IGCTs can be turned-ON with few volts applied; this latter aspect was proved by means of specific tests. Finally, a comparison between a static only and a hybrid CB is performed, highlighting the benefits introduced by the hybrid solution. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
36. Installation, Commissioning and Tests of Four Fast Switching Units of up to 20 kA for the JT-60SA Nuclear Fusion Experiment.
- Author
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Lampasi, Alessandro, Burini, Filippo, Taddia, Giuseppe, Tenconi, Sandro, Matsukawa, Makoto, Shimada, Katsuhiro, Novello, Luca, Jokinen, Antti, and Zito, Pietro
- Subjects
NUCLEAR fusion ,SOLENOIDS ,SOLENOIDS (Mathematics) ,TECHNOLOGICAL innovations ,COMPUTER simulation - Abstract
The nuclear fusion project JT-60SA is presently under construction in Naka (Japan) as a joint collaboration between Europe and Japan, within the framework of the Broader Approach Agreement. According to such agreement, the various JT-60SA systems are supplied by European and Japanese institutions. In particular, the Italian Agency ENEA was in charge for the procurement of the four Switching Network Units (SNUs) for the JT-60SA Central Solenoid (CS). The main SNU function is to interrupt a DC current up to 20 kA in a short time (less than 1 ms) in order to produce an overvoltage of up to 5 kV, crucial to generate and sustain the fusion plasma. The SNU design, manufacturing and factory test activities have been completed in 2016. After the delivery in Naka, the four SNUs have been installed and successfully commissioned in 2017. After an overview on the main technical characteristics of the SNUs and the key aspects of their design, this paper describes the activities performed on-site, highlighting the results obtained during the final acceptance tests and comparing them with the design simulation and the factory test results. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
37. Final design of the Switching Network Units for the JT-60SA Central Solenoid.
- Author
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Lampasi, Alessandro, Coletti, Alberto, Novello, Luca, Matsukawa, Makoto, Burini, Filippo, Taddia, Giuseppe, and Tenconi, Sandro
- Subjects
- *
SOLENOIDS , *ELECTROMECHANICAL effects , *NETWORK switching subsystem , *SUPERCONDUCTORS , *COMPUTER simulation , *TOKAMAKS - Abstract
Abstract: This paper describes the approved detailed design of the four Switching Network Units (SNUs) of the superconducting Central Solenoid of JT-60SA, the satellite tokamak that will be built in Naka, Japan, in the framework of the “Broader Approach” cooperation agreement between Europe and Japan. The SNUs can interrupt a current of 20kA DC in less than 1ms in order to produce a voltage of 5kV. Such performance is obtained by inserting an electronic static circuit breaker in parallel to an electromechanical contactor and by matching and coordinating their operations. Any undesired transient overvoltage is limited by an advanced snubber circuit optimized for this application. The SNU resistance values can be adapted to the specific operation scenario. In particular, after successful plasma breakdown, the SNU resistance can be reduced by a making switch. The design choices of the main SNU elements are justified by showing and discussing the performed calculations and simulations. In most cases, the developed design is expected to exceed the performances required by the JT-60SA project. [Copyright &y& Elsevier]
- Published
- 2014
- Full Text
- View/download PDF
38. Studies on the requirements of the power supply system for the resistive-wall-mode control in JT-60SA.
- Author
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Ferro, Alberto, Gaio, Elena, Takechi, Manabu, Matsukawa, Makoto, and Novello, Luca
- Subjects
- *
ELECTRIC power , *TOKAMAKS , *NATURAL satellites , *HIGH-beta plasma , *ELECTROMAGNETIC shielding , *ELECTRIC coils - Abstract
Abstract: The JT-60SA satellite tokamak will be built in Naka, Japan. One of the main aims of this machine is to achieve steady-state high-beta plasmas. To reach this result, passive stabilizing plate (SP) and resistive wall modes (RWM) active control system based on 18 in-vessel coils will be installed. In the present design, these coils are placed on the plasma side of the SP, behind the first wall. This solution maximizes the efficiency in producing fast magnetic fields into the plasma by minimizing the shielding effect of the passive structures. Then, if the power supply (PS) and the control system have sufficient dynamic performance, it is possible to control the RWM with very low magnetic fields. This allows minimizing the Ampere-turns and the power requested to control the RWM. Conversely, the very fast dynamics required represents one of the main issues for the design of the RWM control system. This paper, after having recalled the main specification data for the RWM control system deriving from the physics studies, describes the analyses performed to complete the set of requirements necessary for the PS design. The characterization of coils and feeders is shown and the voltage necessary to produce the required current and bandwidth is quantified. Possible connections among PS and coils are analyzed in order to achieve the highest possible flexibility in controlling the RWM with a reduced set of independent PS. Finally, considerations on reasonable voltage margins to cope with load uncertainties are given. [Copyright &y& Elsevier]
- Published
- 2013
- Full Text
- View/download PDF
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