WorldWideScience

Sample records for sic power devices

  1. Switching Performance Evaluation of Commercial SiC Power Devices (SiC JFET and SiC MOSFET) in Relation to the Gate Driver Complexity

    DEFF Research Database (Denmark)

    Pittini, Riccardo; Zhang, Zhe; Andersen, Michael A. E.

    2013-01-01

    and JFETs. The recent introduction of SiC MOSFET has proved that it is possible to have highly performing SiC devices with a minimum gate driver complexity; this made SiC power devices even more attractive despite their device cost. This paper presents an analysis based on experimental results...... of the switching losses of various commercially available Si and SiC power devices rated at 1200 V (Si IGBTs, SiC JFETs and SiC MOSFETs). The comparison evaluates the reduction of the switching losses which is achievable with the introduction of SiC power devices; this includes analysis and considerations...

  2. SiC Discrete Power Devices

    National Research Council Canada - National Science Library

    Baliga, B

    2000-01-01

    .... The investigation of the poor performance of the 4H-SiC ACCUFETs provided insights for changes in device design and process flow, for improving their breakdown voltage and specific on-resistance...

  3. Performance evaluation of a high power DC-DC boost converter for PV applications using SiC power devices

    Science.gov (United States)

    Almasoudi, Fahad M.; Alatawi, Khaled S.; Matin, Mohammad

    2016-09-01

    The development of Wide band gap (WBG) power devices has been attracted by many commercial companies to be available in the market because of their enormous advantages over the traditional Si power devices. An example of WBG material is SiC, which offers a number of advantages over Si material. For example, SiC has the ability of blocking higher voltages, reducing switching and conduction losses and supports high switching frequency. Consequently, SiC power devices have become the affordable choice for high frequency and power application. The goal of this paper is to study the performance of 4.5 kW, 200 kHz, 600V DC-DC boost converter operating in continuous conduction mode (CCM) for PV applications. The switching behavior and turn on and turn off losses of different switching power devices such as SiC MOSFET, SiC normally ON JFET and Si MOSFET are investigated and analyzed. Moreover, a detailed comparison is provided to show the overall efficiency of the DC-DC boost converter with different switching power devices. It is found that the efficiency of SiC power switching devices are higher than the efficiency of Si-based switching devices due to low switching and conduction losses when operating at high frequencies. According to the result, the performance of SiC switching power devices dominate the conventional Si power devices in terms of low losses, high efficiency and high power density. Accordingly, SiC power switching devices are more appropriate for PV applications where a converter of smaller size with high efficiency, and cost effective is required.

  4. Taking SiC Power Devices to the Final Frontier: Addressing Challenges of the Space Radiation Environment

    Science.gov (United States)

    Lauenstein, Jean-Marie; Casey, Megan

    2017-01-01

    Silicon carbide power device technology has the potential to enable a new generation of aerospace power systems that demand high efficiency, rapid switching, and reduced mass and volume in order to expand space-based capabilities. For this potential to be realized, SiC devices must be capable of withstanding the harsh space radiation environment. Commercial SiC components exhibit high tolerance to total ionizing dose but to date, have not performed well under exposure to heavy ion radiation representative of the on-orbit galactic cosmic rays. Insertion of SiC power device technology into space applications to achieve breakthrough performance gains will require intentional development of components hardened to the effects of these highly-energetic heavy ions. This work presents heavy-ion test data obtained by the authors over the past several years for discrete SiC power MOSFETs, JFETs, and diodes in order to increase the body of knowledge and understanding that will facilitate hardening of this technology to space radiation effects. Specifically, heavy-ion irradiation data taken under different bias, temperature, and ion beam conditions is presented for devices from different manufacturers, and the emerging patterns discussed.

  5. SiC for microwave power transistors

    Energy Technology Data Exchange (ETDEWEB)

    Sriram, S.; Siergiej, R.R.; Clarke, R.C.; Agarwal, A.K.; Brandt, C.D. [Northrop Grumman Sci. and Technol. Center, Pittsburgh, PA (United States)

    1997-07-16

    The advantages of SiC for high power, microwave devices are discussed. The design considerations, fabrication, and experimental results are described for SiC MESFETs and SITs. The highest reported f{sub max} for a 0.5 {mu}m MESFET using semi-insulating 4H-SiC is 42 GHz. These devices also showed a small signal gain of 5.1 dB at 20 GHz. Other 4H-SiC MESFETs have shown a power density of 3.3 W/mm at 850 MHz. The largest SiC power transistor reported is a 450 W SIT measured at 600 MHz. The power output density of this SIT is 2.5 times higher than that of comparable silicon devices. SITs have been designed to operate as high as 3.0 GHz, with a 3 cm periphery part delivering 38 W of output power. (orig.) 28 refs.

  6. A High Power Boost Converter for PV Systems Operating up to 300 kHz using SiC Devices

    DEFF Research Database (Denmark)

    Anthon, Alexander; Zhang, Zhe; Andersen, Michael A. E.

    2014-01-01

    In this paper, a 3kW boost converter for PV applications using SiC devices is introduced. Main focus is to operate the converter over a wide range of switching frequency and to analyze the main loss distributors as well as the efficiency. The switching element is a recently introduced normally...... be operated at full power for a switching frequency of 100 kHz using natural cooling. At 200 kHz the boost converter is capable of operating at full power when forced air cooling is applied having a JFET case temperature of less than 90 C. The case temperature of the JFET increases up to 110 C at a switching...

  7. SiC Power MOSFET with Improved Gate Dielectric

    Energy Technology Data Exchange (ETDEWEB)

    Sbrockey, Nick M. [Structured Materials Industries, Inc., Piscataway, NJ (United States); Tompa, Gary S. [Structured Materials Industries, Inc., Piscataway, NJ (United States); Spencer, Michael G. [Structured Materials Industries, Inc., Piscataway, NJ (United States); Chandrashekhar, Chandra M.V. S. [Structured Materials Industries, Inc., Piscataway, NJ (United States)

    2010-08-23

    In this STTR program, Structured Materials Industries (SMI), and Cornell University are developing novel gate oxide technology, as a critical enabler for silicon carbide (SiC) devices. SiC is a wide bandgap semiconductor material, with many unique properties. SiC devices are ideally suited for high-power, highvoltage, high-frequency, high-temperature and radiation resistant applications. The DOE has expressed interest in developing SiC devices for use in extreme environments, in high energy physics applications and in power generation. The development of transistors based on the Metal Oxide Semiconductor Field Effect Transistor (MOSFET) structure will be critical to these applications.

  8. A novel approach to improving the radiation hardness of SiC Power Devices, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Silicon Carbide Technology for power semiconductors offers a significant improvement in capability that will allow systems to operate at higher voltages and...

  9. Using of the Modern Semiconductor Devices Based on the SiC

    Directory of Open Access Journals (Sweden)

    Pavel Drabek

    2008-01-01

    Full Text Available This paper deals with possibility of application of the semiconductor devices based on the SiC (Silicon Carbide inthe power electronics. Basic synopsis of SiC based materials problems are presented, appreciation of their properties incomparison with current using power semiconductor devices ((IGBT, MOSFET, CoolFET transistors.

  10. Development of High-Temperature, High-Power, High-Efficiency, High-Voltage Converters Using Silicon Carbide (SiC) Delivery Order 0003: SiC High Voltage Converters, N-Type Ohmic Contract Development for SiC Power Devices

    National Research Council Canada - National Science Library

    Cheng, Lin; Mazzola, Michael S

    2006-01-01

    ... ? SiC interfaces and silicide top surfaces is important for producing uniformly low contact resistances to achieve device operation at high-current levels without hot spot formation and contact degradation...

  11. Development of Process Technologies for High-Performance MOS-Based SiC Power Switching Devices

    Science.gov (United States)

    2007-08-01

    epilayers studied by positron annihilation and deep level transient spectroscopy ," Appl. Phys. Lett., vol. 90, p. 3377, 2001. [30] L. Storasta, J. P...the projected long-term lifetime is acceptable for power device applications . For devices in which the MOS interface is formed on implanted layers...TRPL) techniques, while deep level centers in the material are characterized by deep-level transient spectroscopy (DLTS). We found that the

  12. A Short-Circuit Safe Operation Area Identification Criterion for SiC MOSFET Power Modules

    DEFF Research Database (Denmark)

    Reigosa, Paula Diaz; Iannuzzo, Francesco; Luo, Haoze

    2017-01-01

    This paper proposes a new method for the investigation of the short-circuit safe operation area (SCSOA) of state-of-the-art SiC MOSFET power modules rated at 1.2 kV based on the variations in SiC MOSFET electrical parameters (e.g., short-circuit current and gate–source voltage). According...... to the experimental results, two different failure mechanisms have been identified, both reducing the short-circuit capability of SiC power modules with respect to discrete SiC devices. Based on such failure mechanisms, two short-circuit safety criteria have been formulated: 1) the short-circuit...

  13. Reliability Concerns for Flying SiC Power MOSFETs in Space

    Science.gov (United States)

    Galloway, K. F.; Witulski, A. F.; Schrimpf, R. D.; Sternberg, A. L.; Ball, D. R.; Javanainen, A.; Reed, R. A.; Sierawski, B. D.; Lauenstein, J-M

    2018-01-01

    SiC power MOSFETs are space-ready in terms of typical reliability measures. However, single event burnout (SEB) often occurs at voltages 50% or lower than specified breakdown. Data illustrating burnout for 1200 V devices is reviewed and the space reliability of SiC MOSFETs is discussed.

  14. Silicon Carbide Power Device Performance Under Heavy-Ion Irradiation

    Science.gov (United States)

    Lauenstein, Jean-Marie; Casey, Megan; Topper, Alyson; Wilcox, Edward; Phan, Anthony; Ikpe, Stanley; LaBel, Ken

    2015-01-01

    Heavy-ion induced degradation and catastrophic failure data for SiC power MOSFETs and Schottky diodes are examined to provide insight into the challenge of single-event effect hardening of SiC power devices.

  15. Breakthrough in Power Electronics from SiC: May 25, 2004 - May 31, 2005

    Energy Technology Data Exchange (ETDEWEB)

    Marckx, D. A.

    2006-03-01

    This report explores the premise that silicon carbide (SiC) devices would reduce substantially the cost of energy of large wind turbines that need power electronics for variable speed generation systems.

  16. Recent progress of ultrahigh voltage SiC devices for particle accelerator

    International Nuclear Information System (INIS)

    Fukuda, Kenji; Tsuji, Takashi; Shiomi, Hiromu; Mizushima, Tomonori; Yonezawa, Yoshiyuki; Kondo, Chikara; Otake, Yuji

    2016-01-01

    Silicon carbide (SiC) is the promising material for next power electronics technology used in the field such as HEV, EV, and railway, electric power infrastructure. SiC enables power devices with low loss to easily operate in an ultrahigh-voltage region because of the high breakdown electric field of SiC. In this paper, we report static and dynamic electric performances of 3300 V class SiC SBDs, IE-MOSFETs, >10 kV PiN diodes and IE-IGBTs. Especially, the electrical characteristics of IE-IGBT with the blocking voltage of 16.5 kV indicate the sufficient ability to convert the thyratron in high power RF system of an accelerator. (author)

  17. Irradiation damage of SiC semiconductor device (I)

    International Nuclear Information System (INIS)

    Park, Ji Yeon; Kim, Weon Ju

    2000-09-01

    This report reviewed the irradiation damage of SiC semiconductor devices and examined a irradiation behavior of SiC single crystal as a pre-examination for evaluation of irradiation behavior of SiC semiconductor devices. The SiC single was crystal irradiated by gamma-beam, N+ ion and electron beam. Annealing examinations of the irradiated specimens also were performed at 500 deg C. N-type 6H-SiC dopped with N+ ion was used and irradiation doses of gamma-beam, N+ion and electron beam were up to 200 Mrad, 1x10 16 N + ions/cm 2 and 3.6 x 10 17 e/cm 2 and 1.08 x 10 18 e/cm 2 , respectively. Irradiation damages were analyzed by the EPR method. Additionally, properties of SiC, information about commercial SiC single crystals and the list of web sites with related to the SiC device were described in the appendix

  18. Irradiation damage of SiC semiconductor device (I)

    Energy Technology Data Exchange (ETDEWEB)

    Park, Ji Yeon; Kim, Weon Ju

    2000-09-01

    This report reviewed the irradiation damage of SiC semiconductor devices and examined a irradiation behavior of SiC single crystal as a pre-examination for evaluation of irradiation behavior of SiC semiconductor devices. The SiC single was crystal irradiated by gamma-beam, N+ ion and electron beam. Annealing examinations of the irradiated specimens also were performed at 500 deg C. N-type 6H-SiC dopped with N+ ion was used and irradiation doses of gamma-beam, N+ion and electron beam were up to 200 Mrad, 1x10{sup 16} N{sup +} ions/cm{sup 2} and 3.6 x 10{sup 17} e/cm{sup 2} and 1.08 x 10{sup 18} e/cm{sup 2} , respectively. Irradiation damages were analyzed by the EPR method. Additionally, properties of SiC, information about commercial SiC single crystals and the list of web sites with related to the SiC device were described in the appendix.

  19. A High-Voltage Low-Power Switched-Capacitor DC-DC Converter Based on GaN and SiC Devices for LED Drivers

    DEFF Research Database (Denmark)

    Fan, Lin; Knott, Arnold; Jørgensen, Ivan Harald Holger

    2018-01-01

    Previous research on switched-capacitor DC-DC converters has focused on low-voltage and/or high-power ranges where the efficiencies are dominated by conduction loss. Switched-capacitor DC-DC converters at high-voltage (> 100 V) low-power (high efficiency and high power density...... are anticipated to emerge. This paper presents a switched-capacitor converter with an input voltage up to 380 V (compatible with rectified European mains) and a maximum output power of 10 W. GaN switches and SiC diodes are analytically compared and actively combined to properly address the challenges at high......-voltage low-current levels, where switching loss becomes significant. Further trade-off between conduction loss and switching loss is experimentally optimized with switching frequencies. Three variant designs of the proposed converter are implemented, and the trade-off between the efficiency and the power...

  20. Loss Model and Efficiency Analysis of Tram Auxiliary Converter Based on a SiC Device

    Directory of Open Access Journals (Sweden)

    Hao Liu

    2017-12-01

    Full Text Available Currently, the auxiliary converter in the auxiliary power supply system of a modern tram adopts Si IGBT as its switching device and with the 1700 V/225 A SiC MOSFET module commercially available from Cree, an auxiliary converter using all SiC devices is now possible. A SiC auxiliary converter prototype is developed during this study. The author(s derive the loss calculation formula of the SiC auxiliary converter according to the system topology and principle and each part loss in this system can be calculated based on the device datasheet. Then, the static and dynamic characteristics of the SiC MOSFET module used in the system are tested, which aids in fully understanding the performance of the SiC devices and provides data support for the establishment of the PLECS loss simulation model. Additionally, according to the actual circuit parameters, the PLECS loss simulation model is set up. This simulation model can simulate the actual operating conditions of the auxiliary converter system and calculate the loss of each switching device. Finally, the loss of the SiC auxiliary converter prototype is measured and through comparison it is found that the loss calculation theory and PLECS loss simulation model is valuable. Furthermore, the thermal images of the system can prove the conclusion about loss distribution to some extent. Moreover, these two methods have the advantages of less variables and fast calculation for high power applications. The loss models may aid in optimizing the switching frequency and improving the efficiency of the system.

  1. Investigation on the Short Circuit Safe Operation Area of SiC MOSFET Power Modules

    DEFF Research Database (Denmark)

    Reigosa, Paula Diaz; Luo, Haoze; Iannuzzo, Francesco

    2016-01-01

    This paper gives a better insight of the short circuit capability of state-of-the-art SiC MOSFET power modules rated at 1.2 kV by highlighting the physical limits under different operating conditions. Two different failure mechanisms have been identified, both reducing the short-circuit capability...... of SiC power modules in respect to discrete SiC devices. Based on such failure mechanisms, two short circuit criteria (i.e., short circuit current-based criterion and gate voltage-based criterion) are proposed in order to ensure their robustness under short-circuit conditions. A Safe Operation Area (SOA...

  2. Development of Simulink-Based SiC MOSFET Modeling Platform for Series Connected Devices

    DEFF Research Database (Denmark)

    Tsolaridis, Georgios; Ilves, Kalle; Reigosa, Paula Diaz

    2016-01-01

    A new MATLAB/Simulink-based modeling platform has been developed for SiC MOSFET power modules. The modeling platform describes the electrical behavior f a single 1.2 kV/ 350 A SiC MOSFET power module, as well as the series connection of two of them. A fast parameter initialization is followed...... by an optimization process to facilitate the extraction of the model’s parameters in a more automated way relying on a small number of experimental waveforms. Through extensive experimental work, it is shown that the model accurately predicts both static and dynamic performances. The series connection of two Si......C power modules has been investigated through the validation of the static and dynamic conditions. Thanks to the developed model, a better understanding of the challenges introduced by uneven voltage balance sharing among series connected devices is possible....

  3. Analysis and Comparison of Si and SiC Power Devices on a Grid-Tie Fuel Cell Energy Storage System

    DEFF Research Database (Denmark)

    Pittini, Riccardo; Anthon, Alexander; Zhang, Zhe

    2014-01-01

    In renewable energy applications power conversion efficiency is major concern. This is especially true for grid-tie energy storage systems based on bidirectional dc-dc and dc-ac converters where power flows through these system components. Latest developments in power semiconductors technology......-tie energy storage systems. Results highlight dc-dc conversion efficiencies up to 98.2% with an isolated topology and dc-ac conversion efficiencies up to 97.7%. Overall system efficiency improvements above 1% are achieved compared to traditional Si devices. Results on efficiency improvement are analyzed...

  4. Long-Term Reliability of a Hard-Switched Boost Power Processing Unit Utilizing SiC Power MOSFETs

    Science.gov (United States)

    Ikpe, Stanley A.; Lauenstein, Jean-Marie; Carr, Gregory A.; Hunter, Don; Ludwig, Lawrence L.; Wood, William; Iannello, Christopher J.; Del Castillo, Linda Y.; Fitzpatrick, Fred D.; Mojarradi, Mohammad M.; hide

    2016-01-01

    Silicon carbide (SiC) power devices have demonstrated many performance advantages over their silicon (Si) counterparts. As the inherent material limitations of Si devices are being swiftly realized, wide-band-gap (WBG) materials such as SiC have become increasingly attractive for high power applications. In particular, SiC power metal oxide semiconductor field effect transistors' (MOSFETs) high breakdown field tolerance, superior thermal conductivity and low-resistivity drift regions make these devices an excellent candidate for power dense, low loss, high frequency switching applications in extreme environment conditions. In this paper, a novel power processing unit (PPU) architecture is proposed utilizing commercially available 4H-SiC power MOSFETs from CREE Inc. A multiphase straight boost converter topology is implemented to supply up to 10 kilowatts full-scale. High Temperature Gate Bias (HTGB) and High Temperature Reverse Bias (HTRB) characterization is performed to evaluate the long-term reliability of both the gate oxide and the body diode of the SiC components. Finally, susceptibility of the CREE SiC MOSFETs to damaging effects from heavy-ion radiation representative of the on-orbit galactic cosmic ray environment are explored. The results provide the baseline performance metrics of operation as well as demonstrate the feasibility of a hard-switched PPU in harsh environments.

  5. Porous silicon carbide (SIC) semiconductor device

    Science.gov (United States)

    Shor, Joseph S. (Inventor); Kurtz, Anthony D. (Inventor)

    1996-01-01

    Porous silicon carbide is fabricated according to techniques which result in a significant portion of nanocrystallites within the material in a sub 10 nanometer regime. There is described techniques for passivating porous silicon carbide which result in the fabrication of optoelectronic devices which exhibit brighter blue luminescence and exhibit improved qualities. Based on certain of the techniques described porous silicon carbide is used as a sacrificial layer for the patterning of silicon carbide. Porous silicon carbide is then removed from the bulk substrate by oxidation and other methods. The techniques described employ a two-step process which is used to pattern bulk silicon carbide where selected areas of the wafer are then made porous and then the porous layer is subsequently removed. The process to form porous silicon carbide exhibits dopant selectivity and a two-step etching procedure is implemented for silicon carbide multilayers.

  6. Silicon Carbide Power Devices and Integrated Circuits

    Science.gov (United States)

    Lauenstein, Jean-Marie; Casey, Megan; Samsel, Isaak; LaBel, Ken; Chen, Yuan; Ikpe, Stanley; Wilcox, Ted; Phan, Anthony; Kim, Hak; Topper, Alyson

    2017-01-01

    An overview of the NASA NEPP Program Silicon Carbide Power Device subtask is given, including the current task roadmap, partnerships, and future plans. Included are the Agency-wide efforts to promote development of single-event effect hardened SiC power devices for space applications.

  7. A survey of SiC power MOSFETs short-circuit robustness and failure mode analysis

    DEFF Research Database (Denmark)

    Ceccarelli, L.; Reigosa, P. D.; Iannuzzo, F.

    2017-01-01

    The aim of this paper is to provide an extensive overview about the state-of-art commercially available SiC power MOSFET, focusing on their short-circuit ruggedness. A detailed literature investigation has been carried out, in order to collect and understand the latest research contribution within...... this topic and create a survey of the present scenario of SiC MOSFETs reliability evaluation and failure mode analysis, pointing out the evolution and improvements as well as the future challenges in this promising device technology....

  8. Advances in SiC materials and devices: an industrial point of view

    Energy Technology Data Exchange (ETDEWEB)

    Siergiej, R.R.; Clarke, R.C.; Sriram, S.; Agarwal, A.K.; Bojko, R.J.; Morse, A.W.; Balakrishna, V.; MacMillan, M.F.; Brandt, C.D. [Northrop Grumman ESSS Sci. and Technol. Center, Pittsburgh, PA (United States); Burk, A.A. Jr. [Northrop Grumman ESSS Adv. Technol. Lab. Baltimore, MD (United States)

    1999-07-30

    Silicon carbide (SiC) is an emerging semiconductor that has proven itself especially well-suited to high temperature power switching and high-frequency power generation. In this paper we examine recent advances in materials development and device performance. In boule growth we have focused on increasing boule diameter and reducing defect counts. Two conductivity types have been developed (1) semi-insulating for MESFETs, and (2) highly conducting boules for SITs and power switches. Very uniform planetary multi-wafer epitaxial layer growth on these wafers is described, in which specular epitaxial layers have been obtained with growth rates of 3-5{mu}m h{sup -1} exhibiting unintentional n-type doping of {proportional_to}1 x 10{sup 15} cm{sup -3}, and room temperature Hall mobilities of {proportional_to}1000 cm{sup 2} V{sup -1} s{sup -1}. Controlled n-type doping between {proportional_to}5 x 10{sup 15} cm{sup -3} and >1 x 10{sup 19} cm{sup -3} has also been demonstrated using nitrogen doping. SiC finds application in high temperature power switching devices and microwave power transistors. MOS turn-off thyristors (MTO{sup TM}) are being investigated as power switches because they offer ease of turn-off, 500 C operation and reduced cooling requirements. In the fabrication of high-power, high-frequency transistors at UHF, L-, S-, and X-bands SiC has been found superior to both silicon and GaAs. For example, a 4H-SiC UHF television module has demonstrated good signal fidelity at the 2000 W PEP level, S-band transistor packages have shown 300 W peak power for radar applications, and 6 W power output has been obtained at X-band. (orig.)

  9. Silicon Carbide (SiC) Power Processing Unit (PPU) for Hall Effect Thrusters

    Science.gov (United States)

    Reese, Bradley

    2015-01-01

    Arkansas Power Electronics International (APEI), Inc., is developing a high-efficiency, radiation-hardened 3.8-kW SiC power supply for the PPU of Hall effect thrusters. This project specifically targets the design of a PPU for the high-voltage Hall accelerator (HiVHAC) thruster, with target specifications of 80- to 160-V input, 200- to 700-V/5A output, efficiency greater than 96 percent, and peak power density in excess of 2.5 kW/kg. The PPU under development uses SiC junction field-effect transistor power switches, components that APEI, Inc., has irradiated under total ionizing dose conditions to greater than 3 MRad with little to no change in device performance.

  10. High efficiency battery converter with SiC devices for residential PV systems

    DEFF Research Database (Denmark)

    Pham, Cam; Teodorescu, Remus; Kerekes, Tamas

    2013-01-01

    The demand for high efficiency and higher power density is a challenge for Si-based semiconductors due to the physical characteristics of material. These can be overcome by employing wide-band-gap materials like SiC. This paper compares a second generator SiC MOSFETs against a normally-on Trench...

  11. Experimental and simulation studies of neutron-induced single-event burnout in SiC power diodes

    Science.gov (United States)

    Shoji, Tomoyuki; Nishida, Shuichi; Hamada, Kimimori; Tadano, Hiroshi

    2014-01-01

    Neutron-induced single-event burnouts (SEBs) of silicon carbide (SiC) power diodes have been investigated by white neutron irradiation experiments and transient device simulations. It was confirmed that a rapid increase in lattice temperature leads to formation of crown-shaped aluminum and cracks inside the device owing to expansion stress when the maximum lattice temperature reaches the sublimation temperature. SEB device simulation indicated that the peak lattice temperature is located in the vicinity of the n-/n+ interface and anode contact, and that the positions correspond to a hammock-like electric field distribution caused by the space charge effect. Moreover, the locations of the simulated peak lattice temperature agree closely with the positions of the observed destruction traces. Furthermore, it was theoretically demonstrated that the period of temperature increase of a SiC power device is two orders of magnitude less than that of a Si power device, using a thermal diffusion equation.

  12. Construction and characterization of spherical Si solar cells combined with SiC electric power inverter

    Science.gov (United States)

    Oku, Takeo; Matsumoto, Taisuke; Hiramatsu, Kouichi; Yasuda, Masashi; Shimono, Akio; Takeda, Yoshikazu; Murozono, Mikio

    2015-02-01

    Spherical silicon (Si) photovoltaic solar cell systems combined with an electric power inverter using silicon carbide (SiC) field-effect transistor (FET) were constructed and characterized, which were compared with an ordinary Si-based converter. The SiC-FET devices were introduced in the direct current-alternating current (DC-AC) converter, which was connected with the solar panels. The spherical Si solar cells were used as the power sources, and the spherical Si panels are lighter and more flexible compared with the ordinary flat Si solar panels. Conversion efficiencies of the spherical Si solar cells were improved by using the SiC-FET.

  13. A Manufacturing Cost and Supply Chain Analysis of SiC Power Electronics Applicable to Medium-Voltage Motor Drives

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, Kelsey [National Renewable Energy Lab. (NREL), Golden, CO (United States); Remo, Timothy [National Renewable Energy Lab. (NREL), Golden, CO (United States); Reese, Samantha [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-03-24

    Wide bandgap (WBG) semiconductor devices are increasingly being considered for use in certain power electronics applications, where they can improve efficiency, performance, footprint, and, potentially, total system cost compared to systems using traditional silicon (Si) devices. Silicon carbide (SiC) devices in particular -- which are currently more mature than other WBG devices -- are poised for growth in the coming years. Today, the manufacturing of SiC wafers is concentrated in the United States, and chip production is split roughly equally between the United States, Japan, and Europe. Established contract manufacturers located throughout Asia typically carry out manufacturing of WBG power modules. We seek to understand how global manufacturing of SiC components may evolve over time by illustrating the regional cost drivers along the supply chain and providing an overview of other factors that influence where manufacturing is sited. We conduct this analysis for a particular case study where SiC devices are used in a medium-voltage motor drive.

  14. SiC MOSFET Switching Power Amplifier Project Summary

    Science.gov (United States)

    Miller, Kenneth E.; Ziemba, Timothy; Prager, James; Slobodov, Ilia; Henson, Alex

    2017-10-01

    Eagle Harbor Technologies has completed a Phase I/II program to develop SiC MOSFET based Switching Power Amplifiers (SPA) for precision magnet control in fusion science applications. During this program, EHT developed several units have been delivered to the Helicity Injected Torus (HIT) experiment at the University of Washington to drive both the voltage and flux circuits of the helicity injectors. These units are capable of switching 700 V at 100 kHz with an adjustable duty cycle from 10 - 90% and a combined total output current of 96 kA for 4 ms (at max current). The SPAs switching is controlled by the microcontroller at HIT, which adjusts the duty cycle to maintain a specific waveform in the injector. The SPAs include overcurrent and shoot-through protection circuity. EHT will present an overview of the program including final results for the SPA waveforms. With support of DOE SBIR.

  15. Single-Event Effects in Silicon and Silicon Carbide Power Devices

    Science.gov (United States)

    Lauenstein, Jean-Marie; Casey, Megan C.; LaBel, Kenneth A.; Topper, Alyson D.; Wilcox, Edward P.; Kim, Hak; Phan, Anthony M.

    2014-01-01

    NASA Electronics Parts and Packaging program-funded activities over the past year on single-event effects in silicon and silicon carbide power devices are presented, with focus on SiC device failure signatures.

  16. High efficiency three-phase power factor correction rectifier using SiC switches

    DEFF Research Database (Denmark)

    Kouchaki, Alireza; Nymand, Morten

    2017-01-01

    This paper presents designing procedure of a high efficiency 5 kW silicon-carbide (SiC) based threephase power factor correction (PFC). SiC switches present low capacitive switching loss compared to the alternative Si switches. Therefore, the switching frequency can be increased and hence the siz...

  17. Development of Universal Controller Architecture for SiC Based Power Electronic Building Blocks

    Science.gov (United States)

    2017-10-30

    SiC Based Power Electronic Building Blocks Award Number Title of Research 30 October 2017 SUBMITTED BY D R. HERBERT L. G INN, Pl DEPT. OF...Naval Research , Philadelphia PA, Aug. 2017. • Ginn, H.L. Bakos J., "Development of Universal Controller Architecture for SiC Based Power Electronic...Controller Implementation for MMC Converters", Workshop on Control Architectures for Modular Power Conversion Systems, Office of Naval Research , Arlington VA

  18. Extraction method of interfacial injected charges for SiC power MOSFETs

    Science.gov (United States)

    Wei, Jiaxing; Liu, Siyang; Li, Sheng; Song, Haiyang; Chen, Xin; Li, Ting; Fang, Jiong; Sun, Weifeng

    2018-01-01

    An improved novel extraction method which can characterize the injected charges along the gate oxide interface for silicon carbide (SiC) power metal-oxide-semiconductor field-effect transistors (MOSFETs) is proposed. According to the different interface situations of the channel region and the junction FET (JFET) region, the gate capacitance versus gate voltage (Cg-Vg) curve of the device can be divided into three relatively independent parts, through which the locations and the types of the charges injected in to the oxide above the interface can be distinguished. Moreover, the densities of these charges can also be calculated by the amplitudes of the shifts in the Cg-Vg curve. The correctness of this method is proved by TCAD simulations. Moreover, experiments on devices stressed by unclamped-inductive-switching (UIS) stress and negative bias temperature stress (NBTS) are performed to verify the validity of this method.

  19. Reactor power control device

    International Nuclear Information System (INIS)

    Ishii, Yoshihiko; Arita, Setsuo; Miyamoto, Yoshiyuki; Fukazawa, Yukihisa; Ishii, Kazuhiko

    1998-01-01

    The present invention provides a reactor power control device capable of enhancing an operation efficiency while keeping high reliability and safety in a BWR type nuclear power plant. Namely, the device of the present invention comprises (1) a means for inputting a set value of a generator power and a set value of a reactor power, (2) a means for controlling the reactor power to either smaller one of the reactor power corresponding to the set value of the generator power and the set value of the reactor power. With such procedures, even if the nuclear power plant is set so as to operate it to make the reactor power 100%, when the generator power reaches the upper limit, the reactor power is controlled with a preference given to the upper limit value of the generator power. Accordingly, safety and reliability are not deteriorated. The operation efficiency of the plant can be improved. (I.S.)

  20. Powering biomedical devices

    CERN Document Server

    Romero, Edwar

    2013-01-01

    From exoskeletons to neural implants, biomedical devices are no less than life-changing. Compact and constant power sources are necessary to keep these devices running efficiently. Edwar Romero's Powering Biomedical Devices reviews the background, current technologies, and possible future developments of these power sources, examining not only the types of biomedical power sources available (macro, mini, MEMS, and nano), but also what they power (such as prostheses, insulin pumps, and muscular and neural stimulators), and how they work (covering batteries, biofluids, kinetic and ther

  1. Single-Event Effects in Silicon Carbide Power Devices

    Science.gov (United States)

    Lauenstein, Jean-Marie; Casey, Megan C.; LaBel, Kenneth A.; Ikpe, Stanley; Topper, Alyson D.; Wilcox, Edward P.; Kim, Hak; Phan, Anthony M.

    2015-01-01

    This report summarizes the NASA Electronic Parts and Packaging Program Silicon Carbide Power Device Subtask efforts in FY15. Benefits of SiC are described and example NASA Programs and Projects desiring this technology are given. The current status of the radiation tolerance of silicon carbide power devices is given and paths forward in the effort to develop heavy-ion single-event effect hardened devices indicated.

  2. Silicon Carbide (SiC) Power Processing Unit (PPU) for Hall Effect Thrusters, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — In this SBIR project, APEI, Inc. is proposing to develop a high efficiency, rad-hard 3.8 kW silicon carbide (SiC) Power Processing Unit (PPU) for Hall Effect...

  3. Manufacturing: SiC Power Electronics for Variable Frequency Motor Drives

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, Kelsey A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Bench Reese, Samantha R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Remo, Timothy W [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-15

    This brochure, published as an annual research highlight of the Clean Energy Manufacturing Analysis Center (CEMAC), summarizes CEMAC analysis of silicon carbide (SiC) power electronics for variable frequency motor drives. The key finding presented is that variations in manufacturing expertise, yields, and access to existing facilities impact regional costs and manufacturing location decisions for SiC ingots, wafers, chips, and power modules more than do core country-specific factors such as labor and electricity costs.

  4. Power plant design study of a high aspect ratio Tokamak using a SiC composite structure

    International Nuclear Information System (INIS)

    Murakami, Y.; Takase, H.; Shinya, K.

    1998-01-01

    The DREAM (drastically easy maintenance) tokamak is a fusion power plant which is designed from the viewpoint of maintenance feasibility. For this purpose, the DREAM reactor uses a plasma with a very high aspect ratio (A) and adopts SiC as a structural material. The choice of SiC affects the design of the core plasma, i.e. large inboard shield thickness, low synchrotron radiation reflectivity, and small plasma elongation for positional stability. The objectives of this study are to explore the feasibility of a high-A device, such as a power plant, and to clarify the technological impact of SiC material on the plasma design. Plasma size is optimized by the physics guidelines similar to ITER. The plasma major and minor radii of DREAM are 16 m and 2 m, respectively, and the average neutron wall load is 2.5 MW m -2 , the maximum toroidal field is 20 T, and the fusion power is 5.5 GW. Steady-state operation is obtained with 50 MW of external current-drive power and 90% bootstrap current. The divertor heat load is estimated to be about 10 MW m -2 . A radiative divertor concept is adopted to achieve a low divertor plasma temperature. The DREAM tokamak concept is found to be a possible candidate for a future power plant with more than 5 GW of fusion power and an acceptable divertor condition. (orig.)

  5. SiC nanofibers grown by high power microwave plasma chemical vapor deposition

    International Nuclear Information System (INIS)

    Honda, Shin-ichi; Baek, Yang-Gyu; Ikuno, Takashi; Kohara, Hidekazu; Katayama, Mitsuhiro; Oura, Kenjiro; Hirao, Takashi

    2003-01-01

    Silicon carbide (SiC) nanofibers have been synthesized on Si substrates covered by Ni thin films using high power microwave chemical vapor deposition (CVD). Characterization using transmission electron microscopy (TEM) combined with electron energy-dispersive X-ray spectroscopy (EDX) revealed that the resultant fibrous nanostructures were assigned to β-SiC with high crystallinity. The formation of SiC nanofibers can be explained by the vapor liquid solid (VLS) mechanism in which precipitation of SiC occurs from the supersaturated Ni nanoparticle containing Si and C

  6. A power measuring device

    International Nuclear Information System (INIS)

    As, R. van.

    1985-01-01

    As a part of the klystron test facility of the Dutch NIKHEF-K accelerator, a sensitive power measuring device has been built. The high-frequency power of a klystron is stored in a water-cooled dummy load. Using a microcomputer, the increase of the water temperature and the water flow rate are transformed to a digital indication of the klystron power. (Auth.)

  7. Power generating device

    Energy Technology Data Exchange (ETDEWEB)

    Onodera, Toshihiro

    1989-05-02

    The existing power generating device consisting of static components only lacks effective measures to utilize solar energy and maintain power generation, hence it is inevitable to make the device much larger and more complicated in order to utilize it as the primary power source for artificial satellites. In view of the above, in order to offer a power generating device useful for the primary power source for satellites which is simple and can keep power generation by solar energy, this invention proposes a power generating device composed of the following elements: (1) a rectangular parallelopiped No. II superconductor plate; (2) a measure to apply a magnetic field to one face of the above superconductor plate; (3) a measure to provide a temperature difference within the range between the starting temperature and the critical temperature of superconductivity to a pair of faces meeting at right angles with the face to which the magnetic field was applied by the above measure; (4) a measure to provide an electrode on each of the other pair of faces meeting at right angles with the face to which the magnetic field was applied by the above measure and form a closed circuit by connecting the each electrode above to each of a pair of electrodes of the load respectively; and (5) a switching measure which is installed in the closed circuit prepared by the above measure and shuts off the closed circuit when the direction of the electric current running the above closed circuit is reversed. 6 figs.

  8. Power source device for thermonuclear device

    International Nuclear Information System (INIS)

    Ozaki, Akira.

    1992-01-01

    The present invention provides a small sized and economical power source device for a thermonuclear device. That is, the device comprises a conversion device having a rated power determined by a power required during a plasma current excitation period and a conversion device having a rated power determined by a power required during a plasma current maintaining period, connected in series to each other. Then, for the former conversion device, power is supplied from an electric power generator and, for the latter, power is supplied from a power system. With such a constitution, during the plasma electric current maintaining period for substantially continuous operation, it is possible to conduct bypassing paired operation for the former conversion device while the electric power generator is put under no load. Further, since a short period rated power may be suffice for the former conversion device and the electric power generator having the great rated power required for the plasma electric current excitation period, they can be reduced in the size and made economical. On the other hand, since the power required for the plasma current maintaining period is relatively small, the capacity of the continuous rated conversion device may be small, and the power can be received from the power system. (I.S.)

  9. Silicon Carbide (SiC) Power Processing Unit (PPU) for Hall Effect Thrusters, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — In this SBIR project, APEI, Inc. is proposing to develop a high efficiency, rad-hard 3.8 kW silicon carbide (SiC) power supply for the Power Processing Unit (PPU) of...

  10. Reactor power control device

    International Nuclear Information System (INIS)

    Doi, Kazuyori.

    1981-01-01

    Purpose: To automatically control the BWR type reactor power by simple and short-time searching the load pattern nearest to the required pattern at a nuclear power plant side. Constitution: The reactor power is automatically regulated by periodical modifying of coefficients fitting to a reactor core model, according as a required load pattern. When a load requirement pattern is given, a simulator estimates the total power change and the axial power distribution change from a xenon density change output calculated by a xenon dynamic characteristic estimating device, and a load pattern capable of being realized is searched. The amount to be recirculated is controlled on the basis of the load patteren thus searched, and the operation of the BWR type reactor is automatically controlled at the side of the nuclear power plant. (Kamimura, M.)

  11. Reactor power measuring device

    International Nuclear Information System (INIS)

    Izumi, Mikio; Sano, Yuji; Seki, Eiji; Yoshida, Toshifumi; Ito, Toshiaki.

    1993-01-01

    The present invention provides a self-powered long detector having a sensitivity over the entire length of a reactor core as an entire control rod withdrawal range of a BWR type reactor, and a reactor power measuring device using a gamma ray thermometer which scarcely causes sensitivity degradation. That is, a hollow protection pipe is disposed passing through the reactor core from the outside of a reactor pressure vessel. The self-powered long detectors and the gamma ray thermometers are inserted and installed in the protection pipe. An average reactor power in an axial direction of the reactor relative to a certain position in the horizontal cross section of the reactor core is determined based on the power of the self-powered long detector over the entire length of the reactor core. Since the response of the self-powered detector relative to a local power change is rapid, the output is used as an input signal to a safety protection device of the reactor core. Further, a gamma ray thermometer secured in the reactor and having scarce sensitivity degradation is used instead of an incore travelling neutron monitor used for relative calibration of an existent neutron monitor secured in the reactor. (I.S.)

  12. A Novel DBC Layout for Current Imbalance Mitigation in SiC MOSFET Multichip Power Modules

    DEFF Research Database (Denmark)

    Li, Helong; Munk-Nielsen, Stig; Beczkowski, Szymon

    2016-01-01

    This paper proposes a novel Direct Bonded Copper (DBC) layout for mitigating the current imbalance among the paralleled SiC MOSFET dies in multichip power modules. Compared to the traditional layout, the proposed DBC layout significantly reduces the circuit mismatch and current coupling effect......, which consequently improves the current sharing among the paralleled SiC MOSFET dies in power module. Mathematic analysis and circuit model of the DBC layout are presented to elaborate on the superior features of the proposed DBC layout. Simulation and experimental results further verify the theoretical...

  13. Reactor power monitoring device

    International Nuclear Information System (INIS)

    Kono, Shigehiro.

    1990-01-01

    Among a plurality of power monitoring programs in a reactor power monitoring device, rapid response is required for a scram judging program for the power judging processing of scram signals. Therefore, the scram judging program is stored independently from other power monitoring programs, applied with a priority order, and executed in parallel with other programs, to output scram signals when the detected data exceeds a predetermined value. As a result, the capacity required for the scram judging program is reduced and the processing can be conducted in a short period of time. In addition, since high priority is applied to the scram judging program which is divided into a small capacity, it is executed at higher frequency than other programs when they are executed in parallel. That is, since the entire processings for the power monitoring program are repeated in a short cycle, the response speed of the scram signals required for high responsivity can be increased. (N.H.)

  14. UV laser drilling of SiC for semiconductor device fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Krueger, Olaf; Schoene, Gerd; Wernicke, Tim; John, Wilfred; Wuerfl, Joachim; Traenkle, Guenther [Ferdinand-Braun-Institut fuer Hoechstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin (Germany)

    2007-04-15

    Pulsed UV laser processing is used to drill micro holes in silicon carbide (SiC) wafers supporting AlGaN/GaN transistor structures. Direct laser ablation using nanosecond pulses has been proven to provide an efficient way to create through and blind holes in 400 {mu}m thick SiC. When drilling through, openings in the front pads are formed, while blind holes stop {approx}40 {mu}m before the backside and were advanced to the electrical contact pad by subsequent plasma etching without an additional mask. Low induction connections (vias) between the transistor's source pads and the ground on the backside were formed by metallization of the holes. Micro vias having aspect ratios of 5-6 have been processed in 400 {mu}m SiC. The process flow from wafer layout to laser drilling is available including an automated beam alignment that allows a positioning accuracy of {+-}1 {mu}m with respect to existing patterns on the wafer. As proven by electrical dc and rf measurements the laser-assisted via technologies have successfully been implemented into fabrication of AlGaN/GaN high-power transistors.

  15. A Novel DBC Layout for Current Imbalance Mitigation in SiC MOSFET Multichip Power Modules

    DEFF Research Database (Denmark)

    Li, Helong; Munk-Nielsen, Stig; Beczkowski, Szymon

    2016-01-01

    This letter proposes a novel direct bonded copper (DBC) layout for mitigating the current imbalance among the paralleled SiC MOSFET dies in multichip power modules. Compared to the traditional layout, the proposed DBC layout significantly reduces the circuit mismatch and current coupling effect...

  16. Reactor power monitoring device

    International Nuclear Information System (INIS)

    Dogen, Ayumi; Ozawa, Michihiro.

    1983-01-01

    Purpose: To significantly improve the working efficiency of a nuclear reactor by reflecting the control rod history effect on thermal variants required for the monitoring of the reactor operation. Constitution: An incore power distribution calculation section reads the incore neutron fluxes detected by neutron detectors disposed in the reactor to calculate the incore power distribution. A burnup degree distribution calculation section calculates the burnup degree distribution in the reactor based on the thus calculated incore power distribution. A control rod history date store device supplied with the burnup degree distribution renews the stored control rod history data based on the present control rod pattern and the burnup degree distribution. Then, thermal variants of the nuclear reactor are calculated based on the thus renewed control rod history data. Since the control rod history effect is reflected on the thermal variants required for the monitoring of the reactor operation, the working efficiency of the nuclear reactor can be improved significantly. (Seki, T.)

  17. Power control device

    International Nuclear Information System (INIS)

    Fukawa, Naohiro.

    1982-01-01

    Purpose: To alleviate the load of an operator by automatically operating the main controller, the speed controller, etc. of a recirculation control system and safely operating them without erroneous operation for long period of time, thereby improving the efficiency of a plant. Constitution: An electric type hydraulic control device controls loads of a turbine and a generator and outputs a control signal also to the main controller of a recirculation flow rate control system. At this time, the main controller is set at an automatic position, and the speed controller receives a recirculation pump speed signal from the main controller at the automatic position. The speed controller outputs a pump speed control signal to the recirculation pump system, and a reactor generates a power corresponding thereto. When the power control is automatically performed by the recirculation flow rate control, an operator sets a rate of change of the recirculation pump speed and the rate of change of the mean power range monitor at a change rate setting unit. Therefore, the control of the recirculation flow rate under the power control can be substantially entirely automated. (Yoshigara, H.)

  18. High power RF performance test of an improved SiC load

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, W.H.; Kim, S.H.; Park, Y.J. [Pohang Accelerator Lab., Pohang Inst. of Sceince and Technology, Pohang (KR)] [and others

    1998-11-01

    Two prototypes of SiC loads sustaining a maximum peak power of 50 MW were fabricated by Nihon Koshuha Co. in Japan. The PAL conducted the high power RF performance tests of SiC loads to verify the operation characteristics for the application to the PLS Linac. The in-situ facility for the K 12 module was used for the test, which consists of a modulator and klystron system, waveguide network, vacuum and cooling system, and RF analyzing equipment. As the test results, no breakdown appeared up to 50 MW peak power of 1 {mu}s pulse width at a repetition rate of 50 Hz. However, as the peak power increased above 20 MW at 4 {mu}s with 10 Hz, the breakdown phenomena has been observed. Analysing the test results with the current operation power level of PLS Linac, it is confirmed that the SiC loads well satisfy the criteria of the PLS Linac operation. (author)

  19. PSpice Modeling Platform for SiC Power MOSFET Modules with Extensive Experimental Validation

    DEFF Research Database (Denmark)

    Ceccarelli, Lorenzo; Iannuzzo, Francesco; Nawaz, Muhammad

    2016-01-01

    to simulate the performance of high current rating (above 100 A), multi-chip SiC MOSFET modules both for static and switching behavior. Therefore, the simulation results have been validated experimentally in a wide range of operating conditions, including high temperatures, gate resistance and stray elements....... The whole process has been repeated for three different modules with voltage rating of 1.2 kV and 1.7 kV, manufactured by three different companies. Lastly, a parallel connection of two modules of the same type has been performed in order to observe the unbalancing and mismatches experimentally......The aim of this work is to present a PSpice implementation for a well-established and compact physics-based SiC MOSFET model, including a fast, experimental-based parameter extraction procedure in a MATLAB GUI environment. The model, originally meant for single-die devices, has been used...

  20. Reactor power control device

    International Nuclear Information System (INIS)

    Imaruoka, Hiromitsu.

    1994-01-01

    A high pressure water injection recycling system comprising injection pipelines of a high pressure water injection system and a flow rate control means in communication with a pool of a pressure control chamber is disposed to a feedwater system of a BWR type reactor. In addition, the flow rate control means is controlled by a power control device comprising a scram impossible transient event judging section, a required injection flow rate calculation section for high pressure water injection system and a control signal calculation section. Feed water flow rate to be supplied to the reactor is controlled upon occurrence of a scram impossible transient event of the reactor. The scram impossible transient event is judged based on reactor output signals and scram operation demand signals and injection flow rate is calculated based on a predetermined reactor water level, and condensate storage tank water or pressure control chamber pool water is injected to the reactor. With such procedures, water level can be ensured and power can be suppressed. Further, condensate storage tank water of low enthalpy is introduced to the pressure suppression chamber pool to directly control elevation of water temperature and ensure integrity of the pressure vessel and the reactor container. (N.H.)

  1. Construction and evaluation of photovoltaic power generation and power storage system using SiC field-effect transistor inverter

    Energy Technology Data Exchange (ETDEWEB)

    Oku, Takeo, E-mail: oku@mat.usp.ac.jp; Matsumoto, Taisuke; Ohishi, Yuya [Department of Materials Science, The University of Shiga Prefecture, 2500 Hassaka, Hikone, Shiga 522-8533 (Japan); Hiramatsu, Koichi; Yasuda, Masashi [Collaborative Research Center, The University of Shiga Prefecture, 2500 Hassaka, Hikone, Shiga 522-8533 (Japan); Shimono, Akio; Takeda, Yoshikazu [Kyoshin Electric Co. Ltd., 18, Goshonouchi-Nishimachi, Shichijo, Shimogyou-ku, Kyoto 600-8865 (Japan); Murozono, Mikio [Clean Venture 21 Co., 38 Ishihara Douno-Ushirocho, Kissyouin, Minami-ku, Kyoto 601-8355 (Japan)

    2016-02-01

    A power storage system using spherical silicon (Si) solar cells, maximum power point tracking charge controller, lithium-ion battery and a direct current-alternating current (DC-AC) inverter was constructed. Performance evaluation of the DC-AC inverter was carried out, and the DC-AC conversion efficiencies of the SiC field-effect transistor (FET) inverter was improved compared with those of the ordinary Si-FET based inverter.

  2. Construction and evaluation of photovoltaic power generation and power storage system using SiC field-effect transistor inverter

    International Nuclear Information System (INIS)

    Oku, Takeo; Matsumoto, Taisuke; Ohishi, Yuya; Hiramatsu, Koichi; Yasuda, Masashi; Shimono, Akio; Takeda, Yoshikazu; Murozono, Mikio

    2016-01-01

    A power storage system using spherical silicon (Si) solar cells, maximum power point tracking charge controller, lithium-ion battery and a direct current-alternating current (DC-AC) inverter was constructed. Performance evaluation of the DC-AC inverter was carried out, and the DC-AC conversion efficiencies of the SiC field-effect transistor (FET) inverter was improved compared with those of the ordinary Si-FET based inverter

  3. A state-of-the-art compact SiC photovoltaic inverter with maximum power point tracking function

    Science.gov (United States)

    Ando, Yuji; Oku, Takeo; Yasuda, Masashi; Ushijima, Kazufumi; Matsuo, Hiroshi; Murozono, Mikio

    2018-01-01

    We have developed a 150-W SiC-based photovoltaic (PV)-inverter with the maximum power point tracking (MPPT) function. The newly developed inverter achieved a state-of-the-art combination of the weight (0.79 kg) and the volume (790 mm3) as a 150-250 W class PV-inverter. As compared to the original version that we have previously reported, the weight and volume were decreased by 37% and 38%, respectively. This compactness originated from the optimized circuit structure and the increased density of a wiring circuit. Conversion efficiencies of the MPPT charge controller and the direct current (DC)-alternating current (AC) converter reached 96.4% and 87.6%, respectively. These efficiency values are comparable to those for the original version. We have developed a PV power generation system consisting of this inverter, a spherical Si solar cell module, and a 15-V Li-ion laminated battery. The total weight of the system was below 6 kg. The developed system exhibited stable output power characteristics, even when the weather conditions were fluctuated. These compactness, high efficiencies, and excellent stability clearly indicated the feasibility of SiC power devices even for sub-kW class PV power generation systems.

  4. Design of a low parasitic inductance SiC power module with double-sided cooling

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Fei [The University of Tennessee, Knoxville; Liang, Zhenxian [Cree Inc.; Wang, Fei [ORNL; Wang, Zhiqiang [ORNL

    2017-03-01

    In this paper, a low-parasitic inductance SiC power module with double-sided cooling is designed and compared with a baseline double-sided cooled module. With the unique 3D layout utilizing vertical interconnection, the power loop inductance is effectively reduced without sacrificing the thermal performance. Both simulations and experiments are carried out to validate the design. Q3D simulation results show a power loop inductance of 1.63 nH, verified by the experiment, indicating more than 60% reduction of power loop inductance compared with the baseline module. With 0Ω external gate resistance turn-off at 600V, the voltage overshoot is less than 9% of the bus voltage at a load of 44.6A.

  5. Reactor power control device

    International Nuclear Information System (INIS)

    Watanabe, Mitsutaka

    1997-01-01

    Hardware of an analog nuclear instrumentation system is reformed, a function generator is added to a setting calculation circuit of the nuclear instrumentation system, and each of setting lines of the nuclear instrumentation system is set in parallel with an upper limit curve in an operation region defined by a second order or third order equation. Upon transient change of abnormal power elevation during operation, scram signals are generated by power change in the same state as 100% rated operation due to elevation of reactor thermal power. Since the operation limit value relative to transient change due to power elevation can be made substantially equal with the same as that upon rated operation, the operation limit value for partial power operation state can be kept substantially the same level as that upon rated operation. When transition change caused by abnormal control rod withdrawal occurs during operation, a control rod withdrawal inhibition signal can ensure the power elevation width equal with that upon rated power operation, and since the withdrawal inhibition signal is generated in substantially the same withdrawing state, the operation limit value relative to a partial power operation state can be kept at the same level as that during rated operation. (N.H.)

  6. Wireless Power for Mobile Devices

    NARCIS (Netherlands)

    Waffenschmidt, E.

    2011-01-01

    Wireless power transfer allows a convenient, easy to use battery charging of mobile phones and other mobile devices. No hassle with cables and plugs, just place the device on a pad and that’s it. Such asystem even has the potential to become a standard charging solution. Where are the limits for

  7. A High Frequency (HF) Inductive Power Transfer Circuit for High Temperature Applications Using SiC Schottky Diodes

    Science.gov (United States)

    Jordan, Jennifer L.; Ponchak, George E.; Spry, David J.; Neudeck, Philip G.

    2018-01-01

    Wireless sensors placed in high temperature environments, such as aircraft engines, are desirable to reduce the mass and complexity of routing wires. While communication with the sensors is straight forward, providing power wirelessly is still a challenge. This paper introduces an inductive wireless power transfer circuit incorporating SiC Schottky diodes and its operation from room temperature (25 C) to 500 C.

  8. Reactor power control device

    International Nuclear Information System (INIS)

    Kobayashi, Akira.

    1980-01-01

    Purpose: To prevent misoperation in a control system for the adjustment of core coolant flow rate, and the increase in the neutron flux density caused from the misoperation in BWR type reactors. Constitution: In a reactor power control system adapted to control the reactor power by the adjustment of core flow rate, average neutron flux signals of a reactor core, entire core flow rate signals and operation state signals for coolant recycling system are inputted to a microcomputer. The outputs from the computer are sent to a recycling MG set speed controller to control the reactor core flow rate. The computer calculates the change ratio with time in the average neutron flux signals, correlation between the average neutron flux signals and the entire core flow rate signals, change ratio with time in the operation state signals for the coolant recycling system and the like and judges the abnormality in the coolant recycling system based on the calculated results. (Ikeda, J.)

  9. Zero-Power Radio Device.

    Energy Technology Data Exchange (ETDEWEB)

    Brocato, Robert W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2018-02-01

    This report describes an unpowered radio receiver capable of detecting and responding to weak signals transmit ted from comparatively long distances . This radio receiver offers key advantages over a short range zero - power radio receiver previously described in SAND2004 - 4610, A Zero - Power Radio Receiver . The device described here can be fabricated as an integrated circuit for use in portable wireless devices, as a wake - up circuit, or a s a stand - alone receiver operating in conjunction with identification decoders or other electroni cs. It builds on key sub - components developed at Sandia National Laboratories over many years. It uses surface acoustic wave (SAW) filter technology. It uses custom component design to enable the efficient use of small aperture antennas. This device uses a key component, the pyroelectric demodulator , covered by Sandia owned U.S. Patent 7397301, Pyroelectric Demodulating Detector [1] . This device is also described in Sandia owned U.S. Patent 97266446, Zero Power Receiver [2].

  10. Nuclear fusion power supply device

    International Nuclear Information System (INIS)

    Nakagawa, Satoshi.

    1975-01-01

    Object: To use a hybrid power supply device, which comprises a thyristor power supply and a diode power supply, to decrease cost of a nuclear fusion power supply device. Structure: The device comprises a thyristor power supply connected through a closing unit and a diode power supply connected in parallel through a breaker, input of each power supply being applied with an output voltage of a flywheel AC generator. When a current transformer is excited, a disconnecting switch is turned on to close the diode power supply and a current of the current transformer is increased by an automatic voltage regulator to a set value within a predetermined period of time. Next, the current is cut off by a breaker, and when the breaker is in on position, the disconnecting switch is opened to turn on the closing unit. Thus, when a plasma electric current reaches a predetermined value, the breaker is turned on, and the current of the current transformer is controlled by the thyristor power supply. (Kamimura, M.)

  11. Channel Temperature Model for Microwave AlGaN/GaN HEMTs on SiC and Sapphire MMICs in High Power, High Efficiency SSPAs

    Science.gov (United States)

    Freeman, Jon C.

    2004-01-01

    A key parameter in the design trade-offs made during AlGaN/GaN HEMTs development for microwave power amplifiers is the channel temperature. An accurate determination can, in general, only be found using detailed software; however, a quick estimate is always helpful, as it speeds up the design cycle. This paper gives a simple technique to estimate the channel temperature of a generic microwave AlGaN/GaN HEMT on SiC or Sapphire, while incorporating the temperature dependence of the thermal conductivity. The procedure is validated by comparing its predictions with the experimentally measured temperatures in microwave devices presented in three recently published articles. The model predicts the temperature to within 5 to 10 percent of the true average channel temperature. The calculation strategy is extended to determine device temperature in power combining MMICs for solid-state power amplifiers (SSPAs).

  12. SiC MOSFET Based Single Phase Active Boost Rectifier with Power Factor Correction for Wireless Power Transfer Applications

    Energy Technology Data Exchange (ETDEWEB)

    Onar, Omer C [ORNL; Tang, Lixin [ORNL; Chinthavali, Madhu Sudhan [ORNL; Campbell, Steven L [ORNL; Miller (JNJ), John M. [JNJ-Miller PLC

    2014-01-01

    Wireless Power Transfer (WPT) technology is a novel research area in the charging technology that bridges the utility and the automotive industries. There are various solutions that are currently being evaluated by several research teams to find the most efficient way to manage the power flow from the grid to the vehicle energy storage system. There are different control parameters that can be utilized to compensate for the change in the impedance due to variable parameters such as battery state-of-charge, coupling factor, and coil misalignment. This paper presents the implementation of an active front-end rectifier on the grid side for power factor control and voltage boost capability for load power regulation. The proposed SiC MOSFET based single phase active front end rectifier with PFC resulted in >97% efficiency at 137mm air-gap and >95% efficiency at 160mm air-gap.

  13. Fabrication of Very High Efficiency 5.8 GHz Power Amplifiers using AlGaN HFETs on SiC Substrates for Wireless Power Transmission

    Science.gov (United States)

    Sullivan, Gerry

    2001-01-01

    For wireless power transmission using microwave energy, very efficient conversion of the DC power into microwave power is extremely important. Class E amplifiers have the attractive feature that they can, in theory, be 100% efficient at converting, DC power to RF power. Aluminum gallium nitride (AlGaN) semiconductor material has many advantageous properties, relative to silicon (Si), gallium arsenide (GaAs), and silicon carbide (SiC), such as a much larger bandgap, and the ability to form AlGaN/GaN heterojunctions. The large bandgap of AlGaN also allows for device operation at higher temperatures than could be tolerated by a smaller bandgap transistor. This could reduce the cooling requirements. While it is unlikely that the AlGaN transistors in a 5.8 GHz class E amplifier can operate efficiently at temperatures in excess of 300 or 400 C, AlGaN based amplifiers could operate at temperatures that are higher than a GaAs or Si based amplifier could tolerate. Under this program, AlGaN microwave power HFETs have been fabricated and characterized. Hybrid class E amplifiers were designed and modeled. Unfortunately, within the time frame of this program, good quality HFETs were not available from either the RSC laboratories or commercially, and so the class E amplifiers were not constructed.

  14. FY 2000 report on the development of ultra low loss power element technology. Commercialization of next generation power semiconductor device; 2000 nendo choteisonshitsu denryoku soshi gijutsu kaihatsu seika hokokusho. Jisedai power handotai device jitsuyoka chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    For the purpose of contributing to the promotion of development of ultra low loss power element technology, survey was conducted on the present situation, future, etc. of various technologies/systems related to power semiconductor devices. In the industrial equipment field, it is predicted that power semiconductor devices will be increased in the field of application by enlargement of the defense field of IGBT, new MOS structure elements, etc. In the field of home appliances, possibilities are expected of switching loss reduction and electric noise reduction by making SiC high speed diode. As to the space photovoltaic power generation, SiC is expected for various semiconductors such as solar cells, FET for transmitter/amplifier of radio power electric transmission use micro waves, etc. Concerning the radio communication system plan using stratosphere platform, there are technical problems on communication equipment such as antenna and RF circuit, and the role of SiC device is expected to be large. The society where the electrification rate is 80% and fuel cell vehicles are used is a new paradigm, and it is necessary and indispensable to commercialize ultra low loss power elements using SiC. (NEDO)

  15. Mission-profile-based stress analysis of bond-wires in SiC power modules

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Iannuzzo, Francesco; Blaabjerg, Frede

    2016-01-01

    This paper proposes a novel mission-profile-based reliability analysis approach for stress on bond wires in Silicon Carbide (SiC) MOSFET power modules using statistics and thermo-mechanical FEM analysis. In the proposed approach, both the operational and environmental thermal stresses are taken...... into account. The approach uses a two-dimension statistical analysis of the operating conditions in a real one-year mission profile sampled at time frames 5 minutes long. For every statistical bin corresponding to a given operating condition, the junction temperature evolution is estimated by a thermal network...... and the mechanical stress on bond wires is consequently extracted by finite-element simulations. In the final step, the considered mission profile is translated in a stress sequence to be used for Rainflow counting calculation and lifetime estimation....

  16. Comparative assessment of 3.3kV/400A SiC MOSFET and Si IGBT power modules

    DEFF Research Database (Denmark)

    Ionita, Claudiu; Nawaz, Muhammad; Ilves, Kalle

    2017-01-01

    In this paper, a comparative evaluation between a commercial 3.3 kV/400 A Si-IGBT and a 3.3 kV/400 A SiC MOSFET power module in half-bridge configuration is presented. With a constant current of 250 A, a lower forward voltage (VDS) drop of 1.6 V is obtained for SiC MOSFET at 300 K compared to Si ...... the pulse duration was increased to 4 μs, where a short-circuit energy of 9.1 J was obtained. The cause of the failure is the thermal runaway leading to a drain-source short....

  17. Circuit mismatch and current coupling effect influence on paralleling SiC MOSFETs in multichip power modules

    DEFF Research Database (Denmark)

    Li, Helong; Beczkowski, Szymon; Munk-Nielsen, Stig

    2015-01-01

    This paper reveals that there are circuit mismatches and a current coupling effect in the direct bonded copper (DBC) layout of a silicon carbide (SiC) MOSFET multichip power module. According to the modelling and the mathematic analysis of the DBC layout, the mismatch of the common source stray i...

  18. New Possibilities of Power Electronic Structures Using SiC Technology

    Directory of Open Access Journals (Sweden)

    Robert Sul

    2006-01-01

    Full Text Available This paper is dedicated to the recent unprecedented boom of SiC electronic technology. The contribution deals with brief survey of those properties. In particular, the differences (both good and bad between SiC electronics technology and well-known silicon VLSI technology are highlighted. Projected performance benefits of SiC electronics are given for several large-scale applications on the end of the contribution. The basic properties of SiC material have been discussed already on the beginning of 80’s, also at our university.

  19. MRI-powered biomedical devices.

    Science.gov (United States)

    Hovet, Sierra; Ren, Hongliang; Xu, Sheng; Wood, Bradford; Tokuda, Junichi; Tse, Zion Tsz Ho

    2017-11-16

    Magnetic resonance imaging (MRI) is beneficial for imaging-guided procedures because it provides higher resolution images and better soft tissue contrast than computed tomography (CT), ultrasound, and X-ray. MRI can be used to streamline diagnostics and treatment because it does not require patients to be repositioned between scans of different areas of the body. It is even possible to use MRI to visualize, power, and control medical devices inside the human body to access remote locations and perform minimally invasive procedures. Therefore, MR conditional medical devices have the potential to improve a wide variety of medical procedures; this potential is explored in terms of practical considerations pertaining to clinical applications and the MRI environment. Recent advancements in this field are introduced with a review of clinically relevant research in the areas of interventional tools, endovascular microbots, and closed-loop controlled MRI robots. Challenges related to technology and clinical feasibility are discussed, including MRI based propulsion and control, navigation of medical devices through the human body, clinical adoptability, and regulatory issues. The development of MRI-powered medical devices is an emerging field, but the potential clinical impact of these devices is promising.

  20. 10kV SiC MOSFET split output power module

    DEFF Research Database (Denmark)

    Beczkowski, Szymon; Li, Helong; Uhrenfeldt, Christian

    2015-01-01

    The poor body diode performance of the first generation of 10kV SiC MOSFETs and the parasitic turn-on phenomenon limit the performance of SiC based converters. Both these problems can potentially be mitigated using a split output topology. In this paper we present a comparison between a classical...

  1. Silicon Carbide (SiC) Device and Module Reliability, Performance of a Loop Heat Pipe Subjected to a Phase-Coupled Heat Input to an Acceleration Field

    Science.gov (United States)

    2016-05-01

    AFRL-RQ-WP-TR-2016-0108 SILICON CARBIDE (SiC) DEVICE AND MODULE RELIABILITY Performance of a Loop Heat Pipe Subjected to a Phase-Coupled...CARBIDE (SiC) DEVICE AND MODULE RELIABILITY Performance of a Loop Heat Pipe Subjected to a Phase-Coupled Heat Input to an Acceleration Field 5a...Shukla, K., “Thermo-fluid dynamics of Loop Heat Pipe Operation,” International Communications in Heat and Mass Transfer , Vol. 35, No. 8, 2008, pp

  2. Fiscal 1999 research report. Development of ultralow- loss power device technology (Survey on next-generation practical power semiconductor devices); 1999 nendo choteisonshitsu denryoku soshi gijutsu kaihatsu seika hokokusho. Jisedai power handotai device jitsuyoka chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    This research proposes the clear developmental policy and target for 'Development project of ultralow-loss power device technology' through the research on power electronics or advanced power semiconductor devices as key technology of conversion loss reduction for various power applications and power supply systems. Main research issues are as follows. A bidirectional current switch using P-MOS FETs is promising as an ace of power system interconnection control equipment. IEGT as MOS gate high-power device will be substituted for GTO gradually. SiC devices will play the leading part of low- loss power devices for inverters of power converters, power systems of electric vehicles, Shinkansen and maglev railways, power systems of information and communication systems, and DC power systems. Size and cost reduction of low-noise soft switching as application technology of power devices are possible by using active circuits. Development of high- efficiency low-noise compact inexpensive inverters is an important issue. Countermeasures against various losses of inverters are also described. (NEDO)

  3. Ultra-Lightweight, High Efficiency Silicon-Carbide (SIC) Based Power Electronic Converters, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business of Innovation Research Phase I proposal seeks to investigate and prove the feasibility of developing highly efficient, ultra-lightweight SiC...

  4. Nuclear reactor power control device

    International Nuclear Information System (INIS)

    Koshi, Yuji; Sakata, Akira; Karatsu, Hiroyuki.

    1987-01-01

    Purpose: To control abrupt changes in neutron fluxes by feeding back a correction signal obtained from a deviation between neutron fluxes and heat fluxes for changing the reactor core flow rate to a recycling flow rate control system upon abrupt power change of a nuclear reactor. Constitution: In addition to important systems, that is, a reactor pressure control system and a recycling control system in the power control device of a BWR type power plant, a control circuit for feeding back a deviation between neutron fluxes and heat fluxes to a recycling flow rate control system is disposed. In the suppression circuit, a deviation signal is prepared in an adder from neutron flux and heat flux signals obtained through a primary delay filter. The deviation signal is passed through a dead band and an advance/delay filter into a correction signal, which is adapted to be fed back to the recycling flow rate control system. As a result, the reactor power control can be conducted smoothly and it is possible to effectively suppress the abrupt change or over shoot of the neutron fluxes and abrupt power change. (Kamimura, M.)

  5. Silicon-Carbide (SIC) Multichip Power Modules (MCPMS) For Power Building Block Applications, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project seeks to prove the feasibility of developing high power density modular power electronic building blocks...

  6. End user reliability assessment of 1.2-1.7 kV commercial SiC MOSFET power modules

    DEFF Research Database (Denmark)

    Ionita, Claudiu; Nawaz, Muhammad

    2017-01-01

    This paper is a first attempt to offer reliability evaluation of full SiC power modules where several dies are connected in parallel to increase power rating capability. Here, five different power modules with voltage rating from 1.2-1.7 kV and current rating from 120-800 A from three vendors hav......, which is connected in parallel with the MOSFET chip. For another module, there has also been recorded a failure of the gate oxide during H3TRB....

  7. Trapping Effects in GaN and SiC Microwave FETs

    National Research Council Canada - National Science Library

    Binari, Steven C; Klein, P. B; Kazior, Thomas E

    2002-01-01

    ...). This is particularly true for the wide bandgap devices. In this paper, we review the various trapping phenomena observed in SiC- and GaN-based FETs that contribute to compromised power performance...

  8. Power control device of an atomic power plant

    International Nuclear Information System (INIS)

    Ootsuka, Shiro; Ito, Takero.

    1980-01-01

    Purpose: To improve the power controllability of an atomic power plant by improving the controllability, response and stability of the recirculation flow rate. Constitution: The power control device comprises a power detector of the reactor, which detects and operates the reactor power from the thermal power, neutron flux or the process quantity controlling the same, and a deviation detector which seeks deviation between the power signal of the power detector and the power set value of the reactor or power station. By use of the power control device constituted in this manner, the core flow rate is regulated by the power signal of the deviation detector thereby to control the power. (Aizawa, K.)

  9. Anodization Mechanism on SiC Nanoparticle Reinforced Al Matrix Composites Produced by Power Metallurgy.

    Science.gov (United States)

    Ferreira, Sonia C; Conde, Ana; Arenas, María A; Rocha, Luis A; Velhinho, Alexandre

    2014-12-19

    Specimens of aluminum-based composites reinforced by silicon carbide nanoparticles (Al/SiC np ) produced by powder metallurgy (PM) were anodized under voltage control in tartaric-sulfuric acid (TSA). In this work, the influence of the amount of SiC np on the film growth during anodizing was investigated. The current density versus time response and the morphology of the porous alumina film formed at the composite surface are compared to those concerning a commercial aluminum alloy (AA1050) anodized under the same conditions. The processing method of the aluminum alloys influences the efficiency of the anodizing process, leading to a lower thicknesses for the unreinforced Al-PM alloy regarding the AA1050. The current density versus time response is strongly dependent on the amount of SiC np . The current peaks and the steady-state current density recorded at each voltage step increases with the SiC np volume fraction due to the oxidation of the SiC np . The formation mechanism of the anodic film on Al/SiC np composites is different from that occurring in AA1050, partly due the heterogeneous distribution of the reinforcement particles in the metallic matrix, but also to the entrapment of SiC np in the anodic film.

  10. A Fast Electro-Thermal Co-Simulation Modeling Approach for SiC Power MOSFETs

    DEFF Research Database (Denmark)

    Ceccarelli, Lorenzo; Bahman, Amir Sajjad; Iannuzzo, Francesco

    2017-01-01

    The purpose of this work is to propose a novel electro-thermal co-simulation approach for the new generation of SiC MOSFETs, by development of a PSpice-based compact and physical SiC MOSFET model including temperature dependency of several parameters and a Simulink-based thermal network. The PSpice...... the FEM simulation of the DUT’s structure, performed in ANSYS Icepack. A MATLAB script is used to process the simulation data and feed the needed settings and parameters back into the simulation. The parameters for a CREE 1.2 kV/30 A SiC MOSFET have been identified and the electro-thermal model has been...

  11. Study of Power Loss Reduction in SEPR Converters for Induction Heating through Implementation of SiC Based Semiconductor Switches

    Directory of Open Access Journals (Sweden)

    Angel Marinov

    2014-08-01

    Full Text Available This paper presents a power loss analysis for a Single Ended Parallel Resonance (SEPR Converter used for induction heating. The analysis includes a comparison of the losses in the electronic switch when the circuit is realized using a conventional Silicon (Si based IGBT or when using Silicon Carbide (SiC based MOSFET. The analysis includes modelling and simulation as well as experimental verification through power loss and heat dissipation measurement. The presented results can be used as a base of comparison between the switches and can be a starting point for efficiency based design of those types of converters.

  12. Raman Channel Temperature Measurement of SiC MESFET as a Function of Ambient Temperature and DC Power

    Science.gov (United States)

    Ponchak, George E.; Eldridge, Jeffrey J.; Krainsky, Isay L.

    2009-01-01

    Raman spectroscopy is used to measure the junction temperature of a Cree SiC MESFET as a function of the ambient temperature and DC power. The carrier temperature, which is approximately equal to the ambient temperature, is varied from 25 C to 450 C, and the transistor is biased with VDS=10V and IDS of 50 mA and 100 mA. It is shown that the junction temperature is approximately 52 and 100 C higher than the ambient temperature for the DC power of 500 and 1000 mW, respectively.

  13. Reactor power region measuring device

    International Nuclear Information System (INIS)

    Kashiwa, Takao.

    1996-01-01

    The device of the present invention can rapidly detect abnormality of a local power region monitor (LPRM) even at a low power region caused such as upon start-up of a BWR type reactor. Namely, the present invention comprises (1) an LPRM detector for measuring neutron fluxes in the reactor, (2) a gamma thermo detector for calibrating the sensitivity of the LPRM detector, (3) a comparison circuit for comparing the detected values of the detectors (1) and (2), and (4) an alarm circuit for outputting an alarm when the comparative difference of the output of the circuit (3) exceeds a predetermined value. Signals of an alarm for a lower limit of the LPRM detector have been issued continuously upon start-up and shut down of the reactor since neutron fluxes in the reactor are reduced. However, the gamma thermo detector is always secured in the inside of the reactor different from a travelling-type incore probe monitor (TIP) disposed so far for the same purpose. Accordingly, the alarm generated upon usual start-up can be eliminated by comparing the detected values of the detector (2) and abnormality of the detector (1) can be rapidly detected by judging the abnormality of the comparative difference. (I.S.)

  14. Reliability Assessment of SiC Power MOSFETs From The End User's Perspective

    DEFF Research Database (Denmark)

    Karaventzas, Vasilios Dimitris; Nawaz, Muhammad; Iannuzzo, Francesco

    2016-01-01

    The reliability of commercial Silicon Carbide (SiC) Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) is investigated, and comparative assessment is performed under various test environments. The MOSFETs are tested both regarding the electrical properties of the dies and the packaging...

  15. Design and Fabrication of Silicon-on-Silicon-Carbide Substrates and Power Devices for Space Applications

    Directory of Open Access Journals (Sweden)

    Gammon P.M.

    2017-01-01

    Full Text Available A new generation of power electronic semiconductor devices are being developed for the benefit of space and terrestrial harsh-environment applications. 200-600 V lateral transistors and diodes are being fabricated in a thin layer of silicon (Si wafer bonded to silicon carbide (SiC. This novel silicon-on-silicon-carbide (Si/SiC substrate solution promises to combine the benefits of silicon-on-insulator (SOI technology (i.e device confinement, radiation tolerance, high and low temperature performance with that of SiC (i.e. high thermal conductivity, radiation hardness, high temperature performance. Details of a process are given that produces thin films of silicon 1, 2 and 5 μm thick on semi-insulating 4H-SiC. Simulations of the hybrid Si/SiC substrate show that the high thermal conductivity of the SiC offers a junction-to-case temperature ca. 4× less that an equivalent SOI device; reducing the effects of self-heating, and allowing much greater power density. Extensive electrical simulations are used to optimise a 600 V laterally diffused metal-oxide-semiconductor field-effect transistor (LDMOSFET implemented entirely within the silicon thin film, and highlight the differences between Si/SiC and SOI solutions.

  16. Maximizing electrical power supply using FACTS devices

    OpenAIRE

    Lehmann, Karsten; Bent, Russell; Pan, Feng

    2015-01-01

    Modern society critically depends on the services electric power provides. Power systems rely on a network of power lines and transformers to deliver power from sources of power (generators) to the consumers (loads). However, when power lines fail (for example, through lightning or natural disasters) or when the system is heavily used, the network is often unable to fulfill all of the demand for power. While systems are vulnerable to these failures, increasingly, sophisticated control devices...

  17. Gallium nitride vertical power devices on foreign substrates: a review and outlook

    Science.gov (United States)

    Zhang, Yuhao; Dadgar, Armin; Palacios, Tomás

    2018-07-01

    Vertical gallium nitride (GaN) power devices have attracted increased attention due to their superior high-voltage and high-current capacity as well as easier thermal management than lateral GaN high electron mobility transistors. Vertical GaN devices are promising candidates for next-generation power electronics in electric vehicles, data centers, smart grids and renewable energy process. The use of low-cost foreign substrates such as silicon (Si) substrates, instead of the expensive free-standing GaN substrates, could greatly trim material cost and enable large-diameter wafer processing while maintaining high device performance. This review illustrates recent progress in material epitaxy, device design, device physics and processing technologies for the development of vertical GaN power devices on low-cost foreign substrates. Although the device technologies are still at the early stage of development, state-of-the-art vertical GaN-on-Si power diodes have already shown superior Baliga’s figure of merit than commercial SiC and Si power devices at the voltage classes beyond 600 V. Furthermore, we unveil the design space of vertical GaN power devices on native and different foreign substrates, from the analysis of the impact of dislocation and defects on device performance. We conclude by identifying the application space, current challenges and exciting research opportunities in this very dynamic research field.

  18. Separation Test Method for Investigation of Current Density Effects on Bond Wires of SiC Power MOSFET Modules

    DEFF Research Database (Denmark)

    Luo, Haoze; Iannuzzo, Francesco; Blaabjerg, Frede

    2017-01-01

    and average temperature during the test. By analyzing the output characteristics of the linear region of MOSFET, the constraint relations among the gate voltage, on-state voltage drop and junction temperature are revealed in this paper. The one-to-one correspondence between gate voltage and conduction power...... loss can be used to adjust the current density under fixed temperature swing and average temperature. The commercial Silicon Carbide (SiC) MOSFET modules are tested to experimentally verify the proposed method. Finally, the effectiveness of proposed test method is validated by the experimental results....

  19. Power semiconductor device adaptive cooling assembly

    NARCIS (Netherlands)

    2011-01-01

    The invention relates to a power semiconductor device (100) cooling assembly for cooling a power semiconductor device (100), wherein the assembly comprises an actively cooled heat sink (102) and a controller (208; 300), wherein the controller (208; 300) is adapted for adjusting the cooling

  20. Monitoring device for the reactor power distribution

    International Nuclear Information System (INIS)

    Uematsu, Hitoshi; Tsuiki, Makoto

    1982-01-01

    Purpose: To enable accurate monitoring for the power distribution in a short time, as well as independent detection for in-core neutron flux detectors in abnormal operation due to failures or like other causes to thereby surely provide reliable substitute values. Constitution: Counted values are inputted from a reactor core present status data detector by a power distribution calculation device to calculate the in-core neutron flux density and the power distribution based on previously stored physical models. While on the other hand, counted value from the in-core neutron detectors and the neutron flux distribution and the power distribution calculated from the power distribution calculation device are inputted from a BCF calculation device to compensate the counting errors incorporated in the counted value from the in-core neutron flux detectors and the calculation errors incorporated in the power distribution calculated in the power distribution calculation device respectively and thereby calculate the power distribution in the reactor core. Further, necessary data are inputted to the power distribution calculation device by an input/output device and the results calculated in the BCF calculation device are displayed. (Aizawa, K.)

  1. 30 nm T-gate enhancement-mode InAlN/AlN/GaN HEMT on SiC substrates for future high power RF applications

    Science.gov (United States)

    Murugapandiyan, P.; Ravimaran, S.; William, J.

    2017-08-01

    The DC and RF performance of 30 nm gate length enhancement mode (E-mode) InAlN/AlN/GaN high electron mobility transistor (HEMT) on SiC substrate with heavily doped source and drain region have been investigated using the Synopsys TCAD tool. The proposed device has the features of a recessed T-gate structure, InGaN back barrier and Al2O3 passivated device surface. The proposed HEMT exhibits a maximum drain current density of 2.1 A/mm, transconductance {g}{{m}} of 1050 mS/mm, current gain cut-off frequency {f}{{t}} of 350 GHz and power gain cut-off frequency {f}\\max of 340 GHz. At room temperature the measured carrier mobility (μ), sheet charge carrier density ({n}{{s}}) and breakdown voltage are 1580 cm2/(V \\cdot s), 1.9× {10}13 {{cm}}-2, and 10.7 V respectively. The superlatives of the proposed HEMTs are bewitching competitor or future sub-millimeter wave high power RF VLSI circuit applications.

  2. Recent progress in power electronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Yasuhiko; Yatsuo, Tsutomu

    1987-02-01

    Recent progress and future trends of power semiconductor devices (especially with respect to motor speed control) were described. Conventional discrete devices such as thyristors, bipolar transistors, unipolar transistors and Bi-MOS devices were referenced to. Reference was also made to High Voltage ICs. There has been steady progress with each of these power devices in current carrying capability, voltage blocking capability and switching speed. The Bipolar-MOS integreated device and the High Voltage IC are particularly interesting because their abilities and performances are much enhanced by skillful combination with conventional discrete devices. However, no one device meets all the needs, and it will always be necessary to select the right device for a specific task. (11 figs, 35 refs)

  3. Power distribution forecasting device for reactors

    International Nuclear Information System (INIS)

    Tsukii, Makoto

    1981-01-01

    Purpose: To save expensive calculations on the forecasting of reactor power distribution. Constitution: Core status (CSD) such as entire coolant flow rate, pressures in the reactor, temperatures at the outlet and inlet and positions for control rods are inputted into a power distribution calculation device to calculate the power distribution based on physical models intermittently. Further, present power distribution is calculated based on in-core neutron flux measured values and CSD in a process control computer. Further, the ratio of the calculation results of the latter to those of the former is calculated, stored and inputted into a correction device to correct the forecast power distribution obtained by the power distribution calculation device. This enables to forecast the power distribution with excellent responsivity in the reactor site. (Furukawa, Y.)

  4. Wireless power pad with local power activation for portable devices

    NARCIS (Netherlands)

    Waffenschmidt, E.; Zheglov, V.

    2007-01-01

    Wireless power transfer by magnetic induction offers a simple to use way to recharge mobile devices like e.g. mobile phone, music players or medical sensors. As shown by a previous report and an existing Power Pad demonstrator, wireless inductive power transfer is possible with a good power

  5. Unsupervised Power Profiling for Mobile Devices

    DEFF Research Database (Denmark)

    Kjærgaard, Mikkel Baun; Blunck, Henrik

    Today, power consumption is a main limitation for mobile phones. To minimize the power consumption of popular and traditionally power-hungry location-based services requires knowledge of how individual phone features consume power, so that those features can be utilized intelligently for optimal...... power savings while at the same time maintaining good quality of service. This paper proposes an unsupervised API-level method for power profiling mobile phones based on genetic algorithms. The method enables accurate profiling of the power consumption of devices and thereby provides the information...

  6. Unsupervised Power Profiling for Mobile Devices

    DEFF Research Database (Denmark)

    Kjærgaard, Mikkel Baun; Blunck, Henrik

    2011-01-01

    Today, power consumption is a main limitation for mobile phones. To minimize the power consumption of popular and traditionally power-hungry location-based services requires knowledge of how individual phone features consume power, so that those features can be utilized intelligently for optimal...... power savings while at the same time maintaining good quality of service. This paper proposes an unsupervised API-level method for power profiling mobile phones based on genetic algorithms. The method enables accurate profiling of the power consumption of devices and thereby provides the information...

  7. SiC Seeded Crystal Growth

    Science.gov (United States)

    Glass, R. C.; Henshall, D.; Tsvetkov, V. F.; Carter, C. H., Jr.

    1997-07-01

    The availability of relatively large (30 mm) SiC wafers has been a primary reason for the renewed high level of interest in SiC semiconductor technology. Projections that 75 mm SiC wafers will be available in 2 to 3 years have further peaked this interest. Now both 4H and 6H polytypes are available, however, the micropipe defects that occur to a varying extent in all wafers produced to date are seen by many as preventing the commercialization of many types of SiC devices, especially high current power devices. Most views on micropipe formation are based around Frank's theory of a micropipe being the hollow core of a screw dislocation with a huge Burgers vector (several times the unit cell) and with the diameter of the core having a direct relationship with the magnitude of the Burgers vector. Our results show that there are several mechanisms or combinations of these mechanisms which cause micropipes in SiC boules grown by the seeded sublimation method. Additional considerations such as polytype variations, dislocations and both impurity and diameter control add to the complexity of producing high quality wafers. Recent results at Cree Research, Inc., including wafers with micropipe densities of less than 1 cm - 2 (with 1 cm2 areas void of micropipes), indicate that micropipes will be reduced to a level that makes high current devices viable and that they may be totally eliminated in the next few years. Additionally, efforts towards larger diameter high quality substrates have led to production of 50 mm diameter 4H and 6H wafers for fabrication of LEDs and the demonstration of 75 mm wafers. Low resistivity and semi-insulating electrical properties have also been attained through improved process and impurity control. Although challenges remain, the industry continues to make significant progress towards large volume SiC-based semiconductor fabrication.

  8. Power conditioning devices in nuclear power plants

    International Nuclear Information System (INIS)

    Shida, Toichi.

    1979-01-01

    Purpose: To automatically prevent the liquid level from lowering in a reactor even if a feedwater adjusting valve is locked in a bwr type nuclear power plant. Constitution: Where a feedwater adjusting valve should be locked, and if the mismatching degree between the main steam flow rate and the feedwater flow rate exceeds a predetermined value and the mismatched state continues for a certain period, the value set to a main control for setting the recycling flow rate is changed corresponding to the mismatching degree to compensate the same thereby preventing the liquid level from lowering in the reactor. (Ikeda, J.)

  9. Advanced High Voltage Power Device Concepts

    CERN Document Server

    Baliga, B Jayant

    2012-01-01

    Advanced High Voltage Power Device Concepts describes devices utilized in power transmission and distribution equipment, and for very high power motor control in electric trains and steel-mills. Since these devices must be capable of supporting more than 5000-volts in the blocking mode, this books covers operation of devices rated at 5,000-V, 10,000-V and 20,000-V. Advanced concepts (the MCT, the BRT, and the EST) that enable MOS-gated control of power thyristor structures are described and analyzed in detail. In addition, detailed analyses of the silicon IGBT, as well as the silicon carbide MOSFET and IGBT, are provided for comparison purposes. Throughout the book, analytical models are generated to give a better understanding of the physics of operation for all the structures. This book provides readers with: The first comprehensive treatment of high voltage (over 5000-volts) power devices suitable for the power distribution, traction, and motor-control markets;  Analytical formulations for all the device ...

  10. Super-adiabatic combustion in Al2O3 and SiC coated porous media for thermoelectric power conversion

    International Nuclear Information System (INIS)

    Mueller, Kyle T.; Waters, Oliver; Bubnovich, Valeri; Orlovskaya, Nina; Chen, Ruey-Hung

    2013-01-01

    The combustion of ultra-lean fuel/air mixtures provides an efficient way to convert the chemical energy of hydrocarbons and low-calorific fuels into useful power. Matrix-stabilized porous medium combustion is an advanced technique in which a solid porous medium within the combustion chamber conducts heat from the hot gaseous products in the upstream direction to preheat incoming reactants. This heat recirculation extends the standard flammability limits, allowing the burning of ultra-lean and low-calorific fuel mixtures and resulting a combustion temperature higher than the thermodynamic equilibrium temperature of the mixture (i.e., super-adiabatic combustion). The heat generated by this combustion process can be converted into electricity with thermoelectric generators, which is the goal of this study. The design of a porous media burner coupled with a thermoelectric generator and its testing are presented. The combustion zone media was a highly-porous alumina matrix interposed between upstream and downstream honeycomb structures with pore sizes smaller than the flame quenching distance, preventing the flame from propagating outside of the central section. Experimental results include temperature distributions inside the combustion chamber and across a thermoelectric generator; along with associated current, voltage and power output values. Measurements were obtained for a catalytically inert Al 2 O 3 medium and a SiC coated medium, which was tested for the ability to catalyze the super-adiabatic combustion. The combustion efficiency was obtained for stoichiometric and ultra-lean (near the lean flammability limit) mixtures of CH 4 and air. - Highlights: • Design of a porous burner coupled with a thermoelectric module. • Super-adiabatic combustion in a highly-porous ceramic matrix was investigated. • Both alumina and silicon carbide ceramic surfaces were used as porous media. • Catalytic properties of Al 2 O 3 and SiC ceramic surfaces were studied

  11. Power calculation of grading device in desintegrator

    Science.gov (United States)

    Bogdanov, V. S.; Semikopenko, I. A.; Vavilov, D. V.

    2018-03-01

    This article describes the analytical method of measuring the secondary power consumption, necessitated by the installation of a grading device in the peripheral part of the grinding chamber in the desintegrator. There is a calculation model for defining the power input of the disintegrator increased by the extra power demand, required to rotate the grading device and to grind the material in the area between the external row of hammers and the grading device. The work has determined the inertia moments of a cylindrical section of the grading device with armour plates. The processing capacity of the grading device is adjusted to the conveying capacity of the auger feeder. The grading device enables one to increase the concentration of particles in the peripheral part of the grinding chamber and the amount of interaction between particles and armour plates as well as the number of colliding particles. The perforated sections provide the output of the ground material with the proper size granules, which together with the effects of armour plates, improves the efficiency of grinding. The power demand to rotate the grading device does not exceed the admissible value.

  12. Microbial Fuel Cells for Powering Navy Devices

    Science.gov (United States)

    2014-01-20

    specific MFC being analyzed. Figure 3 depicts simulated voltage vs. current plots (black curves) and corresponding power vs. current...Powering Navy Devices 7     Fig. 3 – Simulated voltage vs current and power vs current polarization plots for a two- chamber MFC in which membrane...the anode is generated by fermentation of glucose by other microorganisms in the sediment represented by clostridium in Fig. 4. The products of the

  13. An optically controlled SiC lateral power transistor based on SiC/SiCGe super junction structure

    International Nuclear Information System (INIS)

    Pu Hongbin; Cao Lin; Ren Jie; Chen Zhiming; Nan Yagong

    2010-01-01

    An optically controlled SiC/SiCGe lateral power transistor based on superjunction structure has been proposed, in which n-SiCGe/p-SiC superjunction structure is employed to improve device figure of merit. Performance of the novel optically controlled power transistor was simulated using Silvaco Atlas tools, which has shown that the device has a very good response to the visible light and the near infrared light. The optoelectronic responsivities of the device at 0.5 μm and 0.7 μm are 330 mA/W and 76.2 mA/W at 2 V based voltage, respectively. (semiconductor devices)

  14. An optically controlled SiC lateral power transistor based on SiC/SiCGe super junction structure

    Energy Technology Data Exchange (ETDEWEB)

    Pu Hongbin; Cao Lin; Ren Jie; Chen Zhiming; Nan Yagong, E-mail: puhongbin@xaut.edu.c [Xi' an University of Technology, Xi' an 710048 (China)

    2010-04-15

    An optically controlled SiC/SiCGe lateral power transistor based on superjunction structure has been proposed, in which n-SiCGe/p-SiC superjunction structure is employed to improve device figure of merit. Performance of the novel optically controlled power transistor was simulated using Silvaco Atlas tools, which has shown that the device has a very good response to the visible light and the near infrared light. The optoelectronic responsivities of the device at 0.5 {mu}m and 0.7 {mu}m are 330 mA/W and 76.2 mA/W at 2 V based voltage, respectively. (semiconductor devices)

  15. Alternative Solder Bond Packaging Approach for High-Voltage (HV) Pulsed Power Devices

    Science.gov (United States)

    2016-09-01

    triggered into the ON-state with a fiber - optic transmitter once the capacitor has been charged up to the desired voltage of choice with a power supply...substrate, which results in a much higher conductivity compared to highly doped p-type substrates in SiC (Fig. 1). The anode layer was etched using...reactive ion etch and then the mesa of the device was etched for total isolation. The gate contact implant was followed using nitrogen in a box

  16. Operation control device for nuclear power plants

    International Nuclear Information System (INIS)

    Suto, Osamu.

    1982-01-01

    Purpose: To render the controlling functions of a central control console more centralized by constituting the operation controls for a nuclear power plant with computer systems having substantially independent functions such as those of plant monitor controls, reactor monitor management and CRT display and decreasing interactions between each of the systems. Constitution: An input/output device for the input of process data for a nuclear power plant and indication data for a plant control console is connected to a plant supervisory and control computer system and a display computer system, the plant supervisory control computer system and a reactor and management computer system are connected with a CRT display control device, a printer and a CRT display input/output device, and the display computer system is connected with the CRT display control device and the CRT display unit on the central control console, whereby process input can be processed and displayed at high speed. (Yoshino, Y.)

  17. Fiscal 1999 achievement report. Development of ultralow-loss power device technology; 1999 nendo choteisonshitsu denryoku soshi gijutsu kaihtsu seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    The aim is to establish basic technologies for upgrading wide-gap semiconductor devices, fabricated mainly of SiC, in terms of their low-loss, high-speed, and high-power features. In the research and development of ultralow-loss power device technology, progress of the effort is reviewed, problems in the process of research and development are extracted, and technological trends are surveyed. In the development of basic technologies, an SiC crystal growing device is experimentally built and the process of crystal growth is assessed and analyzed, and tasks to discharge for higher quality and larger diameter are extracted. Basic technologies are developed relative to the epitaxial growth, interface control, and conductivity control of SiC etc. In the development of technologies for developing SiC into devices, technological development is carried out for the junction-type FET (field effect transistor), which involves termination structure optimization, high-voltage capability enhancement, and gate-off gain improvement. As for MOSFET (metal oxide semiconductor FET), MOS channel formation technology is developed and device-constructing technology is also developed. As for MESFET (metal-semiconductor FET), micro-processing is established for a success in experimentally building a 0.5{mu}m-long gate. (NEDO)

  18. Si and SiC Schottky diodes in smart power circuits: a comparative study by I-V-T and C-V measurements

    Energy Technology Data Exchange (ETDEWEB)

    Hadzi-Vukovic, J [Infineon Technologies, Siemensstrasse 2, 9500 Villach (Austria); Jevtic, M [Institute for Physics, Pregrevica 118, 11080 Zemun (Serbia and Montenegro); Rothleitner, H [Infineon Technologies, Siemensstrasse 2, 9500 Villach (Austria); Croce, P Del [Infineon Technologies, Siemensstrasse 2, 9500 Villach (Austria)

    2005-01-01

    In this paper we analyze a possibility of manufacturing and implementation of Schottky diodes in the smart power circuits. Three different Schottky diodes, in three different technologies, are realized in Si and SiC processes. The electrical characterizations with I-V-T and C-V measurements are done for all structures. It is shown that Si based Schottky diodes also are suitable to be integrated in the typical smart power circuits.

  19. Si and SiC Schottky diodes in smart power circuits: a comparative study by I-V-T and C-V measurements

    International Nuclear Information System (INIS)

    Hadzi-Vukovic, J; Jevtic, M; Rothleitner, H; Croce, P Del

    2005-01-01

    In this paper we analyze a possibility of manufacturing and implementation of Schottky diodes in the smart power circuits. Three different Schottky diodes, in three different technologies, are realized in Si and SiC processes. The electrical characterizations with I-V-T and C-V measurements are done for all structures. It is shown that Si based Schottky diodes also are suitable to be integrated in the typical smart power circuits

  20. Fundamentals of silicon carbide technology growth, characterization, devices and applications

    CERN Document Server

    Kimoto, Tsunenobu

    2014-01-01

    A comprehensive introduction and up-to-date reference to SiC power semiconductor devices covering topics from material properties to applicationsBased on a number of breakthroughs in SiC material science and fabrication technology in the 1980s and 1990s, the first SiC Schottky barrier diodes (SBDs) were released as commercial products in 2001.  The SiC SBD market has grown significantly since that time, and SBDs are now used in a variety of power systems, particularly switch-mode power supplies and motor controls.  SiC power MOSFETs entered commercial production in 2011, providing rugged, hig

  1. Midfield wireless powering of subwavelength autonomous devices.

    Science.gov (United States)

    Kim, Sanghoek; Ho, John S; Poon, Ada S Y

    2013-05-17

    We obtain an analytical bound on the efficiency of wireless power transfer to a weakly coupled device. The optimal source is solved for a multilayer geometry in terms of a representation based on the field equivalence principle. The theory reveals that optimal power transfer exploits the properties of the midfield to achieve efficiencies far greater than conventional coil-based designs. As a physical realization of the source, we present a slot array structure whose performance closely approaches the theoretical bound.

  2. Large Signal Characterization of Microwave Power Devices

    OpenAIRE

    Teyssier, Jean-Pierre; Barataud, D.; Charbonniaud, C.; De Groote, Fabien; Mayer, Markus; Nébus, Jean-Michel; Quéré, Raymond

    2004-01-01

    This paper presents an overview of nonlinear measurement techniques of microwave power devices and amplifiers. Several useful measurement techniques of nonlinear components available in Europe are described. Trends, especially in the area of high power and time domain measurements, are discussed. Finally, a summary of the TARGET measurement related tasks is proposed, in order to show how TARGET can improve the European capabilities in terms of nonlinear measurements.

  3. Influence of Pt Gate Electrode Thickness on the Hydrogen Gas Sensing Characteristics of Pt/In2O3/SiC Hetero-Junction Devices

    Directory of Open Access Journals (Sweden)

    S. Kandasamy

    2007-09-01

    Full Text Available Hetero-junction Pt/In2O3/SiC devices with different Pt thickness (30, 50 and 90nm were fabricated and their hydrogen gas sensing characteristics have been studied. Pt and In2O3 thin films were deposited by laser ablation. The hydrogen sensitivity was found to increase with decreasing Pt electrode thickness. For devices with Pt thickness of 30 nm, the sensitivity gradually increased with increasing temperature and reached a maximum of 390 mV for 1% hydrogen in air at 530°C. Atomic force microscopy (AFM analysis revealed a decrease in Pt grain size and surface roughness for increasing Pt thickness. The relationship between the gas sensing performance and the Pt film thickness and surface morphology is discussed.

  4. Method and device for controlling reactor power

    International Nuclear Information System (INIS)

    Oohashi, Masahisa; Masuda, Hiroyuki.

    1982-01-01

    Purpose: To enable load following-up operation of a reactor adapted to perform power conditioning by the control of the liquid poison density in the core and by the control rods. Constitution: In a case where the reactor power is repeatedly changed in a reactor having a liquid poison density control device and control rods, the time period for the power control is divided depending on the magnitude of the change with time in the reactivity and the optimum values are set for the injection and removal amount of the liquid poison within the divided period. Then, most parts of the control required for the power change are alloted to the liquid poison that gives no effect on the power distribution while minimizing the movement of the control rods, whereby the power change in the reactor as in the case of the load following-up operation can be practiced with ease. (Kawakami, Y.)

  5. Applications, Prospects and Challenges of Silicon Carbide Junction Field Effect Transistor (SIC JFET

    Directory of Open Access Journals (Sweden)

    Frederick Ojiemhende Ehiagwina

    2016-09-01

    Full Text Available Properties of Silicon Carbide Junction Field Effect Transistor (SiC JFET such as high switching speed, low forward voltage drop and high temperature operation have attracted the interest of power electronic researchers and technologists, who for many years developed devices based on Silicon (Si.  A number of power system Engineers have made efforts to develop more robust equipment including circuits or modules with higher power density. However, it was realized that several available power semiconductor devices were approaching theoretical limits offered by Si material with respect to capability to block high voltage, provide low on-state voltage drop and switch at high frequencies. This paper presents an overview of the current applications of SiC JFET in circuits such as inverters, rectifiers and amplifiers. Other areas of application reviewed include; usage of the SiC JFET in pulse signal circuits and boost converters. Efforts directed toward mitigating the observed increase in electromagnetic interference were also discussed. It also presented some areas for further research, such as having more applications of SiC JFET in harsh, high temperature environment. More work is needed with regards to SiC JFET drivers so as to ensure stable and reliable operation, and reduction in the prices of SiC JFETs through mass production by industries.

  6. Power spectrum analysis for defect screening in integrated circuit devices

    Science.gov (United States)

    Tangyunyong, Paiboon; Cole Jr., Edward I.; Stein, David J.

    2011-12-01

    A device sample is screened for defects using its power spectrum in response to a dynamic stimulus. The device sample receives a time-varying electrical signal. The power spectrum of the device sample is measured at one of the pins of the device sample. A defect in the device sample can be identified based on results of comparing the power spectrum with one or more power spectra of the device that have a known defect status.

  7. Reactor power distribution pattern judging device

    International Nuclear Information System (INIS)

    Ikehara, Tadashi.

    1992-01-01

    The judging device of the present invention comprises a power distribution readout system for intaking a power value from a fuel segment, a neural network having an experience learning function for receiving a power distribution value as an input variant, mapping it into a desirable property and self-organizing the map, and a learning date base storing a plurality of learnt samples. The read power distribution is classified depending on the similarity thereof with any one of representative learnt power distribution, and the corresponding state of the reactor core is outputted as a result of the judgement. When an error is found in the classified judging operation, erroneous cases are additionally learnt by using the experience and learning function, thereby improving the accuracy of the reactor core characteristic estimation operation. Since the device is mainly based on the neural network having a self-learning function and a pattern classification and judging function, a judging device having a human's intuitive pattern recognition performance and a pattern experience and learning performance is obtainable, thereby enabling to judge the state of the reactor core accurately. (N.H.)

  8. Monitoring device for local power peaking coefficients

    International Nuclear Information System (INIS)

    Mihashi, Ishi

    1987-01-01

    Purpose: To determine and monitor the local power peaking coefficients by a method not depending on the combination of fuel types. Constitution: Representative values for the local power distribution can be obtained by determining corresponding burn-up degrees based on the burn-up degree of each of fuel assembly segments obtained in a power distribution monitor and by the interpolation and extrapolation of void coefficients. The typical values are multiplied with compensation coefficients for the control rod effect and coefficients for compensating the effect of adjacent fuel assemblies in a calculation device to obtain typical values for the present local power distribution compensated with all of the effects. Further, the calculation device compares them with typical values of the present local power distribution to obtain an aimed local power peaking coefficient as the maximum value thereof. According to the present invention, since the local power peaking coefficients can be determined not depending on the combination of the kind of fuels, if the combination of fuel assemblies is increased upon fuel change, the amount of operation therefor is not increased. (Kamimura, M.)

  9. Methods for growth of relatively large step-free SiC crystal surfaces

    Science.gov (United States)

    Neudeck, Philip G. (Inventor); Powell, J. Anthony (Inventor)

    2002-01-01

    A method for growing arrays of large-area device-size films of step-free (i.e., atomically flat) SiC surfaces for semiconductor electronic device applications is disclosed. This method utilizes a lateral growth process that better overcomes the effect of extended defects in the seed crystal substrate that limited the obtainable step-free area achievable by prior art processes. The step-free SiC surface is particularly suited for the heteroepitaxial growth of 3C (cubic) SiC, AlN, and GaN films used for the fabrication of both surface-sensitive devices (i.e., surface channel field effect transistors such as HEMT's and MOSFET's) as well as high-electric field devices (pn diodes and other solid-state power switching devices) that are sensitive to extended crystal defects.

  10. Power Approaches for Implantable Medical Devices

    Directory of Open Access Journals (Sweden)

    Achraf Ben Amar

    2015-11-01

    Full Text Available Implantable medical devices have been implemented to provide treatment and to assess in vivo physiological information in humans as well as animal models for medical diagnosis and prognosis, therapeutic applications and biological science studies. The advances of micro/nanotechnology dovetailed with novel biomaterials have further enhanced biocompatibility, sensitivity, longevity and reliability in newly-emerged low-cost and compact devices. Close-loop systems with both sensing and treatment functions have also been developed to provide point-of-care and personalized medicine. Nevertheless, one of the remaining challenges is whether power can be supplied sufficiently and continuously for the operation of the entire system. This issue is becoming more and more critical to the increasing need of power for wireless communication in implanted devices towards the future healthcare infrastructure, namely mobile health (m-Health. In this review paper, methodologies to transfer and harvest energy in implantable medical devices are introduced and discussed to highlight the uses and significances of various potential power sources.

  11. Power mos devices: structures and modelling procedures

    Energy Technology Data Exchange (ETDEWEB)

    Rossel, P.; Charitat, G.; Tranduc, H.; Morancho, F.; Moncoqut

    1997-05-01

    In this survey, the historical evolution of power MOS transistor structures is presented and currently used devices are described. General considerations on current and voltage capabilities are discussed and configurations of popular structures are given. A synthesis of different modelling approaches proposed last three years is then presented, including analytical solutions, for basic electrical parameters such as threshold voltage, on-resistance, saturation and quasi-saturation effects, temperature influence and voltage handling capability. The numerical solutions of basic semiconductor devices is then briefly reviewed along with some typical problems which can be solved this way. A compact circuit modelling method is finally explained with emphasis on dynamic behavior modelling

  12. Piezoelectric Structures and Low Power Generation Devices

    Directory of Open Access Journals (Sweden)

    Irinela CHILIBON

    2016-10-01

    Full Text Available A short overview of different piezoelectric structures and devices for generating renewable electricity under mechanical actions is presented. A vibrating piezoelectric device differs from a typical electrical power source in that it has capacitive rather than inductive source impedance, and may be driven by mechanical vibrations of varying amplitude. Several techniques have been developed to extract energy from the environment. Generally, “vibration energy” could be converted into electrical energy by three techniques: electrostatic charge, magnetic fields and piezoelectric. Mechanical resonance frequency of piezoelectric bimorph transducers depends on geometric size (length, width, and thickness of each layer, and the piezoelectric coefficients of the piezoelectric material. Manufacturing processes and intended applications of several energy harvesting devices are presented.

  13. Power consumption monitoring using additional monitoring device

    Energy Technology Data Exchange (ETDEWEB)

    Truşcă, M. R. C., E-mail: radu.trusca@itim-cj.ro; Albert, Ş., E-mail: radu.trusca@itim-cj.ro; Tudoran, C., E-mail: radu.trusca@itim-cj.ro; Soran, M. L., E-mail: radu.trusca@itim-cj.ro; Fărcaş, F., E-mail: radu.trusca@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath, 400293 Cluj-Napoca (Romania); Abrudean, M. [Technical University of Cluj-Napoca, Cluj-Napoca (Romania)

    2013-11-13

    Today, emphasis is placed on reducing power consumption. Computers are large consumers; therefore it is important to know the total consumption of computing systems. Since their optimal functioning requires quite strict environmental conditions, without much variation in temperature and humidity, reducing energy consumption cannot be made without monitoring environmental parameters. Thus, the present work uses a multifunctional electric meter UPT 210 for power consumption monitoring. Two applications were developed: software which carries meter readings provided by electronic and programming facilitates remote device and a device for temperature monitoring and control. Following temperature variations that occur both in the cooling system, as well as the ambient, can reduce energy consumption. For this purpose, some air conditioning units or some computers are stopped in different time slots. These intervals were set so that the economy is high, but the work's Datacenter is not disturbed.

  14. Radioisotope Power Sources for MEMS Devices,

    International Nuclear Information System (INIS)

    Blanchard, J.P.

    2001-01-01

    Microelectromechanical systems (MEMS) comprise a rapidly expanding research field with potential applications varying from sensors in airbags to more recent optical applications. Depending on the application, these devices often require an on-board power source for remote operation, especially in cases requiring operation for an extended period of time. Previously suggested power sources include fossil fuels and solar energy, but nuclear power sources may provide significant advantages for certain applications. Hence, the objective of this study is to establish the viability of using radioisotopes to power realistic MEMS devices. A junction-type battery was constructed using silicon and a 63 Ni liquid source. A source volume containing 64 microCi provided a power of ∼0.07 nW. A more novel application of nuclear sources for MEMS applications involves the creation of a resonator that is driven by charge collection in a cantilever beam. Preliminary results have established the feasibility of this concept, and future work will optimize the design for various applications

  15. Electrical Parasitics and Thermal Modeling for Optimized Layout Design of High Power SiC Modules

    DEFF Research Database (Denmark)

    Bahman, Amir Sajjad; Blaabjerg, Frede; Dutta, Atanu

    2016-01-01

    , the presented models are verified by a conventional and an optimized power module layout. The optimized layout is designed based on the reduction of stray inductance and temperature in a P-cell and N-cell half-bridge module. The presented models are verified by FEM simulations and also experiment....

  16. Comparison of Low Field Electron Transport in Zincblende and Wurtzite SiC Structures for High Gain Device Modeling

    Directory of Open Access Journals (Sweden)

    Hadi Arabshahi

    2011-01-01

    Full Text Available Temperature and doping dependencies of electron mobility in both wurtzite and zincblende SiC structures have been calculated using an iteravive technique. The following scattering mechanisims, i.e, impurity, polar optical phonon, acoustic phonon, piezoelectric and electron plasmon are inculded in the calculation. Ionized imurity scattering has been treated beyound the Born approximation using the phase-shift analysis. It is found that the electron mobility decreases monotonically as the temperature increases from 100 to 500 K. The low temperature value of electron mobilty increases significantly with increasing doping concentration. The iterative results are in fair agreement with other recent calculations obtained using the relaxation-time approximation and experimental methods.

  17. Switching current imbalance mitigation in power modules with parallel connected SiC MOSFETs

    DEFF Research Database (Denmark)

    Beczkowski, Szymon; Jørgensen, Asger Bjørn; Li, Helong

    2017-01-01

    Multichip power modules use parallel connected chips to achieve high current rating. Due to a finite flexibility in a DBC layout, some electrical asymmetries will occur in the module. Parallel connected transistors will exhibit uneven static and dynamic current sharing due to these asymmetries....... Especially important are the couplings between gate and power loops of individual transistors. Fast changing source currents cause gate voltage imbalances yielding uneven switching currents. Equalizing gate voltages seen by paralleled transistors, done by adjusting source bond wires, is proposed...... in this paper. Analysis is performed on an industry standard DBC layout using numerically extracted module parasitics. The method of tuning individual source inductances shows clear improvement in dynamic current balancing and prevents excessive current overshoot during transistors turn-on....

  18. Report on achievement in developing an ultra low loss power element technology. Survey on practical application of the next generation power semiconductor devices; 1998 nendo choteisonshitsu denryoku soshi gijutsu kaihatsu seika hokokusho. Jisedai power handotai device jitsuyoka chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    Trends were surveyed for development of an ultra low loss power element. Performance improvement has been progressed on power semiconductor elements by using Si as the raw material, but loss reduction has come close to the physical limit. SiC is expected of possibility to go beyond this limit. SiC is so very excellent that its band gap is two to three times greater, insulation breakdown electric field is 7.5 times higher, temperature to become a true semiconductor is three to four times higher than those of Si. The wide gap can reduce high temperature leaking current in p-n junctions, and the increased authenticity temperature can increase the upper limit for operation temperature. The insulation breakdown strength being higher by one digit can reduce the drift layer thickness, and is expected to dramatically reduce the loss. The problem is that high quality crystals have not been obtained to date. One of the promising application fields is electric vehicle. The device currently using the power element in the largest scale is used in frequency converting stations to link the 50-Hz power network in the eastern part of Japan to the 60-Hz network in the western part of Japan. Surveys were carried out on the Sakuma frequency converting station and the New Shinano substation. (NEDO)

  19. Large-power microwave circuit device

    International Nuclear Information System (INIS)

    Suzuki, Kunio

    1987-01-01

    A 250 KW CW circulator and 1 MW CW dammy load are developed as large-power microwave circuit devices for Tristan, and they are shown to have good characteristics. The circulator has a Y-shape and consists of waveguides divided into four parts. Partition plates are provided in the waveguide connected to each port in order to divide the power into four components. A ferrite material which is high in Curie temperature and less likely to suffer from a RF loss is selected to be used in the circulator. Thin disks of this material, which is low in temperature gradient in the direction of thickness, are bonded to the surface of the waveguides with an epoxy adhesive. A magnet is provided at the top and bottom of the main portion of the circulator and the magnetic field is adjusted so that optimum characteristics are achieved. These arrangements result in good electrical and power characteristics. The dammy load of a water loading type is selected because microwave power is easily absorbed in water. A mechanically strong pipe which does not cause a large loss in microwave is mounted in a waveguide and water is passed through it to allow the power to be consumed gradually. A test up to a RF power of 750 KW shows that the temperature rise in the waveguide is 30 deg C. (Nogami, K.)

  20. Portable Hybrid Powered Water Filtration Device

    Directory of Open Access Journals (Sweden)

    Maria Lourdes V. Balansay

    2015-08-01

    Full Text Available The existing water filtration device has features that can be developed to be more useful and functional during emergency situations. The project’s development has been aided by following provisions in PEC, NEC, NEMA and Philippine National Standard for Safe Drinking Water provide standards for the construction of the project. These standards protect both the prototype and the user. These also served as guide for the maintenance of every component. The design of the portable hybrid powered water filtration device shows that the project has more advanced features such as portability and the power supply used such as photovoltaic module solar cells and manually operated generator. This also shows its effectiveness and reliability based on the results of discharging test, water quality test and water production test. Based on analysis of the overall financial aspects, the machine can be profitable and the amount of revenue and operating cost will increase as years pass. Using the proper machine/ tools and methods of fabrication helps in easy assembly of the project. The materials and components used are cost effective and efficient. The best time for charging the battery using solar panel is 9:00 am onwards while the hand crank generator is too slow because the generated current is little. The water filtration device is very efficient regarding the operating hours and water production. The machine may have a great effect to society and economy in generation of clean available water at less cost.

  1. Training device for nuclear power plant operators

    International Nuclear Information System (INIS)

    Schoessow, G. J.

    1985-01-01

    A simulated nuclear energy power plant system with visible internal working components comprising a reactor adapted to contain a liquid with heating elements submerged in the liquid and capable of heating the liquid to an elevated temperature, a steam generator containing water and a heat exchanger means to receive the liquid at an elevated temperature, transform the water to steam, and return the spent liquid to the reactor; a steam turbine receiving high energy steam to drive the turbine and discharging low energy steam to a condenser where the low energy steam is condensed to water which is returned to the steam generator; an electric generator driven by the turbine; indicating means to identify the physical status of the reactor and its contents; and manual and automatic controls to selectively establish normal or abnormal operating conditions in the reactor, steam generator, pressurizer, turbine, electric generator, condenser, and pumps; and to be selectively adjusted to bring the reactor to acceptable operating condition after being placed in an abnormal operation. This device is particularly useful as an education device in demonstrating nuclear reactor operations and in training operating personnel for nuclear reactor systems and also as a device for conducting research on various safety systems to improve the safety of nuclear power plants

  2. Wireless Inductive Power Device Suppresses Blade Vibrations

    Science.gov (United States)

    Morrison, Carlos R.; Provenza, Andrew J.; Choi, Benjamin B.; Bakhle, Milind A.; Min, James B.; Stefko, George L.; Duffy, Kirsten P.; Fougers, Alan J.

    2011-01-01

    Vibration in turbomachinery can cause blade failures and leads to the use of heavier, thicker blades that result in lower aerodynamic efficiency and increased noise. Metal and/or composite fatigue in the blades of jet engines has resulted in blade destruction and loss of lives. Techniques for suppressing low-frequency blade vibration, such as gtuned circuit resistive dissipation of vibratory energy, h or simply "passive damping," can require electronics incorporating coils of unwieldy dimensions and adding unwanted weight to the rotor. Other approaches, using vibration-dampening devices or damping material, could add undesirable weight to the blades or hub, making them less efficient. A wireless inductive power device (WIPD) was designed, fabricated, and developed for use in the NASA Glenn's "Dynamic Spin Rig" (DSR) facility. The DSR is used to simulate the functionality of turbomachinery. The relatively small and lightweight device [10 lb (approx.=4.5 kg)] replaces the existing venerable and bulky slip-ring. The goal is the eventual integration of this technology into actual turbomachinery such as jet engines or electric power generators, wherein the device will facilitate the suppression of potentially destructive vibrations in fan blades. This technology obviates slip rings, which require cooling and can prove unreliable or be problematic over time. The WIPD consists of two parts: a remote element, which is positioned on the rotor and provides up to 100 W of electrical power to thin, lightweight piezoelectric patches strategically placed on/in fan blades; and a stationary base unit that wirelessly communicates with the remote unit. The base unit supplies inductive power, and also acts as an input and output corridor for wireless measurement, and active control command to the remote unit. Efficient engine operation necessitates minimal disturbance to the gas flow across the turbine blades in any effort to moderate blade vibration. This innovation makes it

  3. Application of high power microwave vacuum electron devices

    International Nuclear Information System (INIS)

    Ding Yaogen; Liu Pukun; Zhang Zhaochuan; Wang Yong; Shen Bin

    2011-01-01

    High power microwave vacuum electron devices can work at high frequency, high peak and average power. They have been widely used in military and civil microwave electron systems, such as radar, communication,countermeasure, TV broadcast, particle accelerators, plasma heating devices of fusion, microwave sensing and microwave heating. In scientific research, high power microwave vacuum electron devices are used mainly on high energy particle accelerator and fusion research. The devices include high peak power klystron, CW and long pulse high power klystron, multi-beam klystron,and high power gyrotron. In national economy, high power microwave vacuum electron devices are used mainly on weather and navigation radar, medical and radiation accelerator, TV broadcast and communication system. The devices include high power pulse and CW klystron, extended interaction klystron, traveling wave tube (TWT), magnetron and induced output tube (IOT). The state of art, common technology problems and trends of high power microwave vacuum electron devices are introduced in this paper. (authors)

  4. Comparative study of SiC- and Si-based photovoltaic inverters

    Science.gov (United States)

    Ando, Yuji; Oku, Takeo; Yasuda, Masashi; Shirahata, Yasuhiro; Ushijima, Kazufumi; Murozono, Mikio

    2017-01-01

    This article reports comparative study of 150-300 W class photovoltaic inverters (Si inverter, SiC inverter 1, and SiC inverter 2). In these sub-kW class inverters, the ON-resistance was considered to have little influence on the efficiency. The developed SiC inverters, however, have exhibited an approximately 3% higher direct current (DC)-alternating current (AC) conversion efficiency as compared to the Si inverter. Power loss analysis indicated a reduction in the switching and reverse recovery losses of SiC metal-oxide-semiconductor field-effect transistors used for the DC-AC converter is responsible for this improvement. In the SiC inverter 2, an increase of the switching frequency up to 100 kHz achieved a state-of-the-art combination of the weight (1.25 kg) and the volume (1260 cm3) as a 150-250 W class inverter. Even though the increased switching frequency should cause the increase of the switching losses, the SiC inverter 2 exhibited an efficiency comparable to the SiC inverter 1 with a switching frequency of 20 kHz. The power loss analysis also indicated a decreased loss of the DC-DC converter built with SiC Schottky barrier diodes led to the high efficiency for its increased switching frequency. These results clearly indicated feasibility of SiC devices even for sub-kW photovoltaic inverters, which will be available for the applications where compactness and efficiency are of tremendous importance.

  5. Die degradation effect on aging rate in accelerated cycling tests of SiC power MOSFET modules

    DEFF Research Database (Denmark)

    Luo, Haoze; Baker, Nick; Iannuzzo, Francesco

    2017-01-01

    In order to distinguish the die and bond wire degradations, in this paper both the die and bond wire resistances of SiC MOSFET modules are measured and tested during the accelerated cycling tests. It is proved that, since the die degradation under specific conditions increases the temperature swing...

  6. Development of superconducting power devices in Europe

    International Nuclear Information System (INIS)

    Tixador, Pascal

    2010-01-01

    Europe celebrated last year (2008) the 100-year anniversary of the first liquefaction of helium by H. Kammerling Onnes in Leiden. It led to the discovery of superconductivity in 1911. Europe is still active in the development of superconducting (SC) devices. The discovery of high critical temperature materials in 1986, again in Europe, has opened a lot of opportunities for SC devices by broking the 4 K cryogenic bottleneck. Electric networks experience deep changes due to the emergence of dispersed generation (renewable among other) and to the advances in ICT (Information Communication Technologies). The networks of the future will be 'smart grids'. Superconductivity will offer 'smart' devices for these grids like FCL (Fault Current Limiter) or VLI (Very Low Inductance) cable and would certainly play an important part. Superconductivity also will participate to the required sustainable development by lowering the losses and enhancing the mass specific powers. Different SC projects in Europe will be presented (Cable, FCL, SMES, Flywheel and Electrical Machine) but the description is not exhaustive. Nexans has commercialized the first two FCLs without public funds in the European grid (UK and Germany). The Amsterdam HTS cable is an exciting challenge in term of losses for long SC cables. European companies (Nexans, Air Liquide, Siemens, Converteam, ...) are also very active for projects outside Europe (LIPA, DOE FCL, ...).

  7. Operation guide device for nuclear power plants

    International Nuclear Information System (INIS)

    Araki, Tsuneyasu

    1982-01-01

    Purpose: To enable to maintain the soundness of nuclear fuels and each of equipments by compensating the effect of the xenon density on the reactor core thermal power resulted upon load following operation of a nuclear reactor. Constitution: The device comprises an instrumentation system for measuring the status of the nuclear reactor, a reactor core performance calculator for calculating the reactor core performance based on the output from the instrumentation system, a xenon density calculator for calculating the xenon density based on the output from the performance calculator, a memory unit for storing the output from the reactor core performance calculator and the xenon density calculator and for transferring the stored memory to a nuclear reactor status forecasting device and an alternative load pattern searching device for searching, in cooperation with the memory unit, an alternative load pattern which is within an operation restrictive condition and most closed to a demanded load pattern when a monitor for the deviation from the flowrate distribution detects the deviation from the operation restrictive conditions. (Yoshino, Y.)

  8. Reactor power control device in BWR power plant

    International Nuclear Information System (INIS)

    Kurosawa, Tsuneo.

    1997-01-01

    The present invention provides a device for controlling reactor power based on a start-up/shut down program in a BWR type reactor, as well as for detecting deviation, if occurs, of the power from the start-up/shut down program, to control a recycling flow rate control system or control rod drive mechanisms. Namely, a power instruction section successively executes the start-up/shut down program and controls the coolant recycling system and the control rod driving mechanisms to control the power. A current state monitoring and calculation section receives a process amount, calculates parameters showing the plant state, compares/monitors them with predetermined values, detecting the deviation, if occurs, of the plant state from the start-up/shut down program, and prevents output of a power increase control signal which leads to power increase. A forecasting and monitoring/calculation section forecasts and calculates the plant state when not yet executed steps of the start-up/shut down program are performed, stops the execution of the start-up/shut down program in the next step in a case of forecasting that the results of the calculation will deviate from the start-up/shut down program. (I.S.)

  9. Water quality maintaining device of power plant

    International Nuclear Information System (INIS)

    Kobayashi, Minoru; Inami, Ichiro.

    1994-01-01

    The device of the present invention reduces the amount of leaching materials of ion exchange resins from a water processing system of a BWR tyep plant, improves the water quality of reactor water to maintain the water at high purity. That is, steams used for power generation are condensated in a condensate system. A condensate filter and a condensate desalter for cleaning the condensates are disposed. A resin storage hopper is disposed for supplying the ion exchange resins to the water processing system. A device for supplying a nitrogen gas or an inert gas is disposed in the hopper. With such a constitution, the ion exchange resins in the water processing system are maintained in a nitrogen gas or inert gas atmosphere or at a low dissolved oxygen level in an operation stage in the power plant. Accordingly, degradation of the ion exchange resins in the water processing system is suppressed and the amount of the leaching material from the resins is reduced. As a result, the amount of the resins leached into the reactor is reduced, so that the reactor water quality can be maintained at high purity. (I.S.)

  10. Transient analysis of power systems solution techniques, tools and applications

    CERN Document Server

    Martinez-Velasco, J

    2014-01-01

    A comprehensive introduction and up-to-date reference to SiC power semiconductor devices covering topics from material properties to applicationsBased on a number of breakthroughs in SiC material science and fabrication technology in the 1980s and 1990s, the first SiC Schottky barrier diodes (SBDs) were released as commercial products in 2001.  The SiC SBD market has grown significantly since that time, and SBDs are now used in a variety of power systems, particularly switch-mode power supplies and motor controls.  SiC power MOSFETs entered commercial production in 2011, providing rugged, hig

  11. Robust Control of Wide Bandgap Power Electronics Device Enabled Smart Grid

    Science.gov (United States)

    Yao, Tong

    In recent years, wide bandgap (WBG) devices enable power converters with higher power density and higher efficiency. On the other hand, smart grid technologies are getting mature due to new battery technology and computer technology. In the near future, the two technologies will form the next generation of smart grid enabled by WBG devices. This dissertation deals with two applications: silicon carbide (SiC) device used for medium voltage level interface (7.2 kV to 240 V) and gallium nitride (GaN) device used for low voltage level interface (240 V/120 V). A 20 kW solid state transformer (SST) is designed with 6 kHz switching frequency SiC rectifier. Then three robust control design methods are proposed for each of its smart grid operation modes. In grid connected mode, a new LCL filter design method is proposed considering grid voltage THD, grid current THD and current regulation loop robust stability with respect to the grid impedance change. In grid islanded mode, micro synthesis method combined with variable structure control is used to design a robust controller for grid voltage regulation. For grid emergency mode, multivariable controller designed using Hinfinity synthesis method is proposed for accurate power sharing. Controller-hardware-in-the-loop (CHIL) testbed considering 7-SST system is setup with Real Time Digital Simulator (RTDS). The real TMS320F28335 DSP and Spartan 6 FPGA control board is used to interface a switching model SST in RTDS. And the proposed control methods are tested. For low voltage level application, a 3.3 kW smart grid hardware is built with 3 GaN inverters. The inverters are designed with the GaN device characterized using the proposed multi-function double pulse tester. The inverter is controlled by onboard TMS320F28379D dual core DSP with 200 kHz sampling frequency. Each inverter is tested to process 2.2 kW power with overall efficiency of 96.5 % at room temperature. The smart grid monitor system and fault interrupt devices (FID

  12. Hacking and penetration testing with low power devices

    CERN Document Server

    Polstra, Philip

    2014-01-01

    Hacking and Penetration Testing with Low Power Devices shows you how to perform penetration tests using small, low-powered devices that are easily hidden and may be battery-powered. It shows how to use an army of devices, costing less than you might spend on a laptop, from distances of a mile or more. Hacking and Penetration Testing with Low Power Devices shows how to use devices running a version of The Deck, a full-featured penetration testing and forensics Linux distribution, and can run for days or weeks on batteries due to their low power consumption. Author Philip Polstra shows how to

  13. On the perspectives of wide-band gap power devices in electronic-based power conversion for renewable systems

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcelos Araujo, Samuel

    2013-10-01

    The high breakdown field from WBG materials allows the construction of unipolar devices with very low specific chip resistance mainly characterized by very low conduction and switching losses, even at high blocking voltages. Suitable concepts for SiC and GaN range from traditional FET structures driven by a MOS interface or a PN-Junction, bipolar devices and even high-electron mobility transistors (HEMT). A detailed revision of the literature will be performed in this work with the objective of providing a broad overview of possible approaches, along with inherent advantages and limitations. In addition to this, a benchmarking of several SiC-based devices technologies rated for 1200 V and 1700 V will be performed against their state-of-the-art Silicon-counterparts. Concerning the application of wide band gap devices in renewable energy systems, a significant cost reduction potential can be obtained due to smaller expenditure with magnetic filters and cooling, alongside higher efficiency levels. These aspects will be discussed in details in order to identify constraints and bottlenecks at application level with special focus on photovoltaic and wind power systems.

  14. Frequency-domain thermal modelling of power semiconductor devices

    DEFF Research Database (Denmark)

    Ma, Ke; Blaabjerg, Frede; Andresen, Markus

    2015-01-01

    to correctly predict the device temperatures, especially when considering the thermal grease and heat sink attached to the power semiconductor devices. In this paper, the frequency-domain approach is applied to the modelling of thermal dynamics for power devices. The limits of the existing RC lump...

  15. Development of an efficient DC-DC SEPIC converter using wide bandgap power devices for high step-up applications

    Science.gov (United States)

    Al-bayati, Ali M. S.; Alharbi, Salah S.; Alharbi, Saleh S.; Matin, Mohammad

    2017-08-01

    A highly efficient high step-up dc-dc converter is the major requirement in the integration of low voltage renewable energy sources, such as photovoltaic panel module and fuel cell stacks, with a load or utility. This paper presents the development of an efficient dc-dc single-ended primary-inductor converter (SEPIC) for high step-up applications. Three SEPIC converters are designed and studied using different combinations of power devices: a combination based on all Si power devices using a Si-MOSFET and a Si-diode and termed as Si/Si, a combination based on a hybrid of Si and SiC power devices using the Si-MOSFET and a SiC-Schottky diode and termed as Si/SiC, and a combination based on all SiC power devices using a SiC-MOSFET and the SiC-Schottky diode and termed as SiC/SiC. The switching behavior of the Si-MOSFET and SiC-MOSFET is characterized and analyzed within the different combinations at the converter level. The effect of the diode type on the converter's overall performance is also discussed. The switching energy losses, total power losses, and the overall performance effciency of the converters are measured and reported under different switching frequencies. Furthermore, the potential of the designed converters to operate efficiently at a wide range of input voltages and output powers is studied. The analysis and results show an outstanding performance efficiency of the designed SiC/SiC based converter under a wide range of operating conditions.

  16. Customized electric power storage device for inclusion in a microgrid

    Science.gov (United States)

    Goldsmith, Steven Y.; Wilson, David; Robinett, III, Rush D.

    2017-08-01

    An electric power storage device included in a microgrid is described herein. The electric power storage device has at least one of a charge rate, a discharge rate, or a power retention capacity that has been customized for the microgrid. The at least one of the charge rate, the discharge rate, or the power retention capacity of the electric power storage device is computed based at least in part upon specified power source parameters in the microgrid and specified load parameters in the microgrid.

  17. Reactor power control method and device

    International Nuclear Information System (INIS)

    Fushimi, Atsushi; Ishii, Yoshihiko; Miyamoto, Yoshiyuki; Ishii, Kazuhiko; Kiyoharu, Norihiko; Aizawa, Yuko.

    1997-01-01

    The present invention provides a method and a device suitable to rise the temperature and increase the pressure of the reactor to an aimed pressure in accordance with an aimed value for a reactor water temperature changing rate in the course of rising temperature and increasing pressure of the reactor upon start up of a BWR type power plant. Namely, neutron fluxes in the reactor and the temperature of reactor water are detected respectively. The maximum value among the detected values for the neutron fluxes is detected. The reactor water temperature changing rate is calculated based on the detected values of the reactor water temperature, from which the maximum value of the reactor water temperature changing rate is detected. An aimed value for the neutron flux is calculated in accordance with both detected maximum values and the aimed value of the reactor water temperature changing rate. The position of control rods is adjusted in accordance with the aimed value for the calculated neutron flux. Then, an aimed value for the neutron flux for realizing the aimed value for the reactor water temperature changing rate can be obtained accurately with no influence of the sensitivity of the detected values of the neutron fluxes and the time delay of the reactor water temperature changing rate. (I.S.)

  18. SiC epitaxy growth using chloride-based CVD

    International Nuclear Information System (INIS)

    Henry, Anne; Leone, Stefano; Beyer, Franziska C.; Pedersen, Henrik; Kordina, Olof; Andersson, Sven; Janzén, Erik

    2012-01-01

    The growth of thick epitaxial SiC layers needed for high-voltage, high-power devices is investigated with the chloride-based chemical vapor deposition. High growth rates exceeding 100 μm/h can be obtained, however to obtain device quality epilayers adjustments of the process parameters should be carried out appropriately for the chemistry used. Two different chemistry approaches are compared: addition of hydrogen chloride to the standard precursors or using methyltrichlorosilane, a molecule that contains silicon, carbon and chlorine. Optical and electrical techniques are used to characterize the layers.

  19. Verification of Fowler–Nordheim electron tunneling mechanism in Ni/SiO{sub 2}/n-4H SiC and n{sup +} poly-Si/SiO{sub 2}/n-4H SiC MOS devices by different models

    Energy Technology Data Exchange (ETDEWEB)

    Kodigala, Subba Ramaiah, E-mail: kodigala@gmail.com [Department of Electrical Engineering, University of South Carolina, Columbia, SC 29208 (United States); Department of Physics and Astronomy, Department of Electrical and Computer Engineering, California State University, Northridge, CA 91330 (United States)

    2016-11-01

    This article emphasizes verification of Fowler–Nordheim electron tunneling mechanism in the Ni/SiO{sub 2}/n-4H SiC MOS devices by developing three different kinds of models. The standard semiconductor equations are categorically solved to obtain the change in Fermi energy level of semiconductor with effect of temperature and field that extend support to determine sustainable and accurate tunneling current through the oxide layer. The forward and reverse bias currents with variation of electric field are simulated with help of different models developed by us for MOS devices by applying adequate conditions. The latter is quite different from former in terms of tunneling mechanism in the MOS devices. The variation of barrier height with effect of quantum mechanical, temperature, and fields is considered as effective barrier height for the generation of current–field (J–F) curves under forward and reverse biases but quantum mechanical effect is void in the latter. In addition, the J–F curves are also simulated with variation of carrier concentration in the n-type 4H SiC semiconductor of MOS devices and the relation between them is established.

  20. A High-Efficiency Compact SiC-based Power Converter System, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Wide-bandgap SiC semiconductors have been recently investigated for use in power devices, because of their potential capabilities of operating at high power...

  1. A High-Efficiency Compact SiC-based Power Converter System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Wide bandgap SiC power devices have the potential for reliable operations at higher junction temperatures, higher voltages, higher frequencies and thus higher power...

  2. Power magnetic devices a multi-objective design approach

    CERN Document Server

    Sudhoff, Scott D

    2014-01-01

    Presents a multi-objective design approach to the many power magnetic devices in use today Power Magnetic Devices: A Multi-Objective Design Approach addresses the design of power magnetic devices-including inductors, transformers, electromagnets, and rotating electric machinery-using a structured design approach based on formal single- and multi-objective optimization. The book opens with a discussion of evolutionary-computing-based optimization. Magnetic analysis techniques useful to the design of all the devices considered in the book are then set forth. This material is then used for ind

  3. Transient electro-thermal modeling of bipolar power semiconductor devices

    CERN Document Server

    Gachovska, Tanya Kirilova; Du, Bin

    2013-01-01

    This book presents physics-based electro-thermal models of bipolar power semiconductor devices including their packages, and describes their implementation in MATLAB and Simulink. It is a continuation of our first book Modeling of Bipolar Power Semiconductor Devices. The device electrical models are developed by subdividing the devices into different regions and the operations in each region, along with the interactions at the interfaces, are analyzed using the basic semiconductor physics equations that govern device behavior. The Fourier series solution is used to solve the ambipolar diffusio

  4. Design of Gear Churning Power Loss Measurement Device

    OpenAIRE

    Wang Bin; Zhou Ya Jie; Wang Ping

    2017-01-01

    To explore the impacts of gear churning power losses, a research was conducted to achieve the internal causes of power losses of churning gear by designing a gear churning power losses measurement device. The gear churning power losses could be influenced by different gear modules, the number of teeth and the axial position of gear. Finally, the impacts of gear churning power losses were discussed by comparing experimental data and theoretical data.

  5. Wirelessly powered microfluidic dielectrophoresis devices using printable RF circuits.

    Science.gov (United States)

    Qiao, Wen; Cho, Gyoujin; Lo, Yu-Hwa

    2011-03-21

    We report the first microfluidic device integrated with a printed RF circuit so the device can be wirelessly powered by a commercially available RFID reader. For conventional dielectrophoresis devices, electrical wires are needed to connect the electric components on the microchip to external equipment such as power supplies, amplifiers, function generators, etc. Such a procedure is unfamiliar to most clinicians and pathologists who are used to working with a microscope for examination of samples on microscope slides. The wirelessly powered device reported here eliminates the entire need for wire attachments and external instruments so the operators can use the device in essentially the same manner as they do with microscope slides. The integrated circuit can be fabricated on a flexible plastic substrate at very low cost using a roll-to-roll printing method. Electrical power at 13.56 MHz transmitted by a radio-frequency identification (RFID) reader is inductively coupled to the printed RFIC and converted into 10 V DC (direct current) output, which provides sufficient power to drive a microfluidic device to manipulate biological particles such as beads and proteins via the DC dielectrophoresis (DC-DEP) effect. To our best knowledge, this is the first wirelessly powered microfluidic dielectrophoresis device. Although the work is preliminary, the device concept, the architecture, and the core technology are expected to stimulate many efforts in the future and transform the technology to a wide range of clinical and point-of-care applications. This journal is © The Royal Society of Chemistry 2011

  6. Power control device in nuclear reactor

    International Nuclear Information System (INIS)

    Koyama, Kazuaki.

    1981-01-01

    Purpose: To enable smooth power changes in power conditioning systems by calculating forecast values for the neutron flux distribution and power distribution and by controlling the driving speed of control rods so as to correspond the forecast values with aimed values. Constitution: Control rod position is detected by a position detector and sent to a control computer as the position information. At the same time, the neutron flux distribution information is obtained by the neutron monitors, the power distribution information is obtained by a reactor power computer and they are outputted to the control computer. The control computer calculates the forecast values for the neutron flux distribution and the reactor power distribution from the information, and compares them with the aimed values from a setter and then outputs control signals so as to correspond the forecast values with the aimed values. The control rods can be inserted in appropriate velocity by the control signals. (Horiuchi, T.)

  7. FACTS Devices for Large Wind Power Plants

    DEFF Research Database (Denmark)

    Adamczyk, Andrzej Grzegorz; Teodorescu, Remus; Rodriguez, Pedro

    2010-01-01

    Growing number of wind turbines is changing electricity generation profile all over the world. However, high wind energy penetration affects power system safety and stability. For this reason transmission system operators (TSO) impose more stringent connection requirements on the wind power plant...

  8. Micro-Combined Heat and Power Device Test Facility

    Data.gov (United States)

    Federal Laboratory Consortium — NIST has developed a test facility for micro-combined heat and power (micro-CHP) devices to measure their performance over a range of different operating strategies...

  9. Self-Powered Functional Device Using On-Chip Power Generation

    KAUST Repository

    Hussain, Muhammad Mustafa

    2012-01-26

    An apparatus, system, and method for a self-powered device using on-chip power generation. In some embodiments, the apparatus includes a substrate, a power generation module on the substrate, and a power storage module on the substrate. The power generation module may include a thermoelectric generator made of bismuth telluride.

  10. Self-Powered Functional Device Using On-Chip Power Generation

    KAUST Repository

    Hussain, Muhammad Mustafa

    2012-01-01

    An apparatus, system, and method for a self-powered device using on-chip power generation. In some embodiments, the apparatus includes a substrate, a power generation module on the substrate, and a power storage module on the substrate. The power generation module may include a thermoelectric generator made of bismuth telluride.

  11. Minimum critical power ratio control device for nuclear power plants

    International Nuclear Information System (INIS)

    Kurosawa, Tsuneo.

    1991-01-01

    Reactor core flowrate is determined by comparing a minimum critical power ratio calculated based on the status amount of a nuclear power plant and a control value for the minimum critical power ratio that depends on the reactor core flowrate. Further, the minimum critical power ratio and a control value for the minimum critical power ratio that depends on the reactor thermal power are compared to set a reactor thermal power converted to a reactor core flowrate. Deviation between the thus determined reactor core flowrate and the present reactor core flowrate is calculated. When the obtained deviation is lower than a rated value, a reactor core flowrate set signal is generated to a reactor flowrate control means, to control the reactor power by a recycling flowrate control system of the reactor. On the other hand, when the deviation exceeds the determined value, the reactor core flowrate set signal is converted into a reactor thermal power, to control the position of control rods and control the reactor power. Then, monitor and control can be conducted safely and automatically without depending on operator's individual ability over the entire operation range corresponding to load following operation. (N.H.)

  12. SiC MOSFETs based split output half bridge inverter

    DEFF Research Database (Denmark)

    Li, Helong; Munk-Nielsen, Stig; Beczkowski, Szymon

    2014-01-01

    output. The double pulse test shows the devices' current during commutation process and the reduced switching losses of SiC MOSFETs compared to that of the traditional half bridge. The efficiency comparison is presented with experimental results of half bridge power inverter with split output...... and traditional half bridge inverter, from switching frequency 10 kHz to 100 kHz. The experimental results comparison shows that the half bridge with split output has an efficiency improvement of more than 0.5% at 100 kHz switching frequency....

  13. Monitoring device for local power peaking coefficient

    International Nuclear Information System (INIS)

    Mitsuhashi, Ishi

    1987-01-01

    Purpose: To monitor the local power peaking coefficients obtained by the method not depending on the combination of fuel types. Method: A plurality of representative values for the local power distribution determined by the nuclear constant calculation for one fuel assembly are memorized regarding each of the burn-up degree and the void coefficient on every positions and fuel types in fuel rod assemblies. While on the other hand, the representative values for the local power distribution as described above are compensated by a compensation coefficient considering the effect of adjacent segments and a control rod compensation coefficient considering the effect due to the control rod insertion relative to the just-mentioned compensation coefficient. Then, the maximum value among them is selected to determine the local power peaking coefficient at each of the times and each of the segments, which is monitored. According to this system, the calculation and the working required for the fitting work depending on the combination of fuel types are no more required at all to facilitate the maintenance as well. (Horiuchi, T.)

  14. Auxiliary cooling device for power plant

    International Nuclear Information System (INIS)

    Yamanoi, Kozo.

    1996-01-01

    An auxiliary cooling sea water pipeline for pumping up cooling sea water, an auxiliary cooling sea water pipeline and a primary side of an auxiliary cooling heat exchanger are connected between a sea water taking vessel and a sea water discharge pit. An auxiliary cooling water pump is connected to an auxiliary water cooling pipeline on the second side of the auxiliary cooling heat exchanger. The auxiliary cooling water pipeline is connected with each of auxiliary equipments of a reactor system and each of auxiliary equipments of the turbine system connected to a turbine auxiliary cooling water pipeline in parallel. During ordinary operation of the reactor, heat exchange for each of the auxiliary equipments of the reactor and heat exchange for each of the equipments of the turbine system are conducted simultaneously. Since most portions of the cooling devices of each of the auxiliary equipments of the reactor system and each of the auxiliary equipments of the turbine system can be used in common, the operation efficiency of the cooling device is improved. In addition, the space for the pipelines and the cost for the equipments can be reduced. (I.N.)

  15. SIC Industriemonitor najaar 2003

    NARCIS (Netherlands)

    Brouwer, N.; de Nooij, M.; Pomp, M.

    2003-01-01

    In juni 2000 publiceerde de Stichting voor Economisch Onderzoek (SEO) van de Universiteit van Amsterdam in opdracht van Stichting voor Industriebeleid en Communicatie (SIC) een ontwerp voor een SIC industriemonitor met een voorstel voor de inhoud en de structuur van een dergelijke monitor. Op dat

  16. EMI Evaluation on Wireless Computer Devices in Nuclear Power Plants

    International Nuclear Information System (INIS)

    Lee, Jae Ki; JI Yeong Hwa; Sung, Chan Ho

    2011-01-01

    Wireless computer devices, for example, mice and keyboards are widely used in various industries. However, I and C (instrumentation and control) equipment in nuclear power plants are very susceptible to the EMI (Electro-magnetic interference) and there are concerns regarding EMI induced transient caused by wireless computer devices which emit electromagnetic waves for communication. In this paper, industrial practices and nuclear related international standards are investigated to verify requirements of wireless devices. In addition, actual measurement and evaluation for the intensity of EMI of some commercially available wireless devices is performed to verify their compatibility in terms of EMI. Finally we suggest an appropriate method of using wireless computer devices in nuclear power plant control rooms for better office circumstances of operators

  17. 75 FR 70112 - Medical Devices; General and Plastic Surgery Devices; Classification of Non-Powered Suction...

    Science.gov (United States)

    2010-11-17

    .... FDA-2010-N-0513] Medical Devices; General and Plastic Surgery Devices; Classification of Non-Powered... risks. Adverse tissue reaction Material degradation Improper function of suction apparatus (e.g., reflux.... Material degradation Section 8. Stability and Shelf Life. [[Page 70113

  18. Multi-objective optimal power flow with FACTS devices

    International Nuclear Information System (INIS)

    Basu, M.

    2011-01-01

    This paper presents multi-objective differential evolution to optimize cost of generation, emission and active power transmission loss of flexible ac transmission systems (FACTS) device-equipped power systems. In the proposed approach, optimal power flow problem is formulated as a multi-objective optimization problem. FACTS devices considered include thyristor controlled series capacitor (TCSC) and thyristor controlled phase shifter (TCPS). The proposed approach has been examined and tested on the modified IEEE 30-bus and 57-bus test systems. The results obtained from the proposed approach have been compared with those obtained from nondominated sorting genetic algorithm-II, strength pareto evolutionary algorithm 2 and pareto differential evolution.

  19. A power device material of corundum-structured α-Ga2O3 fabricated by MIST EPITAXY® technique

    Science.gov (United States)

    Kaneko, Kentaro; Fujita, Shizuo; Hitora, Toshimi

    2018-02-01

    Corundum-structured oxides have been attracting much attention as next-generation power device materials. A corundum-structured α-Ga2O3 successfully demonstrated power device operations of Schottky barrier diodes (SBDs) with the lowest on-resistance of 0.1 mΩ cm2. The SBDs as a mounting device of TO220 also showed low switching-loss properties with a capacitance of 130 pF. Moreover, the thermal resistance was 13.9 °C/W, which is comparable to that of the SiC TO220 device (12.5 °C/W). On the other hand, corundum-structured α-(Rh,Ga)2O3 showed p-type conductivity, which was confirmed by Hall effect measurements. The Hall coefficient, carrier density, and mobility were 8.22 cm3/C, 7.6 × 1017/cm3, and 1.0 cm2 V-1 s-1, respectively. These values were acceptable for the p-type layer of pn diodes based on α-Ga2O3.

  20. A Literature Survey on Wireless Power Transfer for Biomedical Devices

    Directory of Open Access Journals (Sweden)

    Reem Shadid

    2018-01-01

    Full Text Available This paper provides a review and survey of research on power transfer for biomedical applications based on inductive coupling. There is interest in wireless power transfer (WPT for implantable and wearable biomedical devices, for example, heart pacemaker or implantable electrocardiogram (ECG recorders. This paper concentrates on the applications based on near-field power transfer methods, summarizes the main design features in the recent literature, and provides some information about the system model and coil optimization.

  1. Reliability-cost models for the power switching devices of wind power converters

    DEFF Research Database (Denmark)

    Ma, Ke; Blaabjerg, Frede

    2012-01-01

    In order to satisfy the growing reliability requirements for the wind power converters with more cost-effective solution, the target of this paper is to establish a new reliability-cost model which can connect the relationship between reliability performances and corresponding semiconductor cost...... temperature mean value Tm and fluctuation amplitude ΔTj of power devices, are presented. With the proposed reliability-cost model, it is possible to enable future reliability-oriented design of the power switching devices for wind power converters, and also an evaluation benchmark for different wind power...... for power switching devices. First the conduction loss, switching loss as well as thermal impedance models of power switching devices (IGBT module) are related to the semiconductor chip number information respectively. Afterwards simplified analytical solutions, which can directly extract the junction...

  2. Advantages and Limits of 4H-SIC Detectors for High- and Low-Flux Radiations

    Science.gov (United States)

    Sciuto, A.; Torrisi, L.; Cannavò, A.; Mazzillo, M.; Calcagno, L.

    2017-11-01

    Silicon carbide (SiC) detectors based on Schottky diodes were used to monitor low and high fluxes of photons and ions. An appropriate choice of the epilayer thickness and geometry of the surface Schottky contact allows the tailoring and optimizing the detector efficiency. SiC detectors with a continuous front electrode were employed to monitor alpha particles in a low-flux regime emitted by a radioactive source with high energy (>5.0 MeV) or generated in an ion implanter with sub-MeV energy. An energy resolution value of 0.5% was measured in the high energy range, while, at energy below 1.0 MeV, the resolution becomes 10%; these values are close to those measured with a traditional silicon detector. The same SiC devices were used in a high-flux regime to monitor high-energy ions, x-rays and electrons of the plasma generated by a high-intensity (1016 W/cm2) pulsed laser. Furthermore, SiC devices with an interdigit Schottky front electrode were proposed and studied to overcome the limits of the such SiC detectors in the detection of low-energy (˜1.0 keV) ions and photons of the plasmas generated by a low-intensity (1010 W/cm2) pulsed laser. SiC detectors are expected to be a powerful tool for the monitoring of radioactive sources and ion beams produced by accelerators, for a complete characterization of radiations emitted from laser-generated plasmas at high and low temperatures, and for dosimetry in a radioprotection field.

  3. Homoepitaxial VPE growth of SiC active layers

    Energy Technology Data Exchange (ETDEWEB)

    Burk, A.A. Jr. [Northrop Grumman Electron. Sensors and Syst. Div., Baltimore, MD (United States); Rowland, L.B. [Northrop Grumman Sci. and Technol. Center, Pittsburgh, PA (United States)

    1997-07-01

    SiC active layers of tailored thickness and doping form the heart of all SiC electronic devices. These layers are most conveniently formed by vapor phase epitaxy (VPE). Exacting requirements are placed upon the SiC-VPE layers` material properties by both semiconductor device physics and available methods of device processing. In this paper, the current ability of the SiC-VPE process to meet these requirements is described along with continuing improvements in SiC epitaxial reactors, processes and materials. (orig.) 48 refs.

  4. Fire extinguishing device for nuclear power plant

    International Nuclear Information System (INIS)

    Arakawa, Ken

    1990-01-01

    Fire extinguishing pipelines disposed in turbine buildings of low earthquake proof grade and fire extinguishing pipelines disposed in reactor buildings of high earthquakes proof grade have been used in common with each other. Accordingly, if the fire extinguishing device in the turbine buildings designed for low earthquake proof grade are partially destroyed upon occurrence of medium-scale earthquakes, there is a worry that fire extinguishing water can not be supplied to the inside of the reactor buildings. In view of the above, an emergency fire extinguishing water system using a fire extinguishing reservoir at the outdoor of low earthquake proof grade as a feedwater source and suitable to the low earthquake proof grade is disposed in the turbine buildings. Another emergency fire extinguishing water system using an emergency fire extinguishing water reservoir disposed in the reactor buildings as a feedwater source and suitable to the high earthquake proof grade is disposed in the reactor buildings. Then, ordinary fire extinguishing water system and the emergency fire extinguishing water system are connected to each other. Thus, upon occurrence of earthquakes if the function of the ordinary fire extinguishing water system of low earthquake proof grade is lost, fires breaking out in the reactor buildings can rapidly be extinguished. (N.H.)

  5. Accident analysis device for nuclear power plants

    International Nuclear Information System (INIS)

    Ito, Masayuki.

    1982-01-01

    Purpose: To enable rapid recognition of and countermeasure required for accidents upon scram, by identifying the first contact point of causes for resulting the scram and displaying the contact point of causes. Constitution: When a scram signal is inputted by way of process input device, the time of the input is determined by a timer and the contact point of causes generated just before is taken as the point whose changes occurred prior to but most closely to the generation of the signal while referring to the data memory section for the time of change of the contact point of the cause, and sent to the accident analyzing display. The accident analyzing display extracts, based on the contact point of cause, a list for the forecast accidents corresponding thereto from the data memory section and also extracts the list for the corresponding confirmation items of the accident detection and displays them together with the system from which the scram signal has been generated, the time of generation, the name of the contact point of causes operated at first, and the value of the state quantity contained in the data memory section for the store of contact point of cause at the change. (Kawakami, Y.)

  6. Power control device for nuclear reactors

    International Nuclear Information System (INIS)

    Kagawa, Tatsuo

    1984-01-01

    Purpose: To eliminate for requirement of control rods and movable portions, as well as ensure the safety and reliability of the operation. Constitution: A plurality of control tubes are disposed within a reactor core instead of control rods. Tubes are connected from below the reactor core to the control tubes for supplying liquid poisons such as aqueous boric acid to the inside of the control tubes. Further, tubes are connected to the upper portion of the control tubes for guiding the liquid poisons from the reactor core to the outside. The tubes for supplying and discharging the liquid poisons are introduced externally through the flange disposed at the upper portion of a pressure vessel. At the outside of the pressure vessel, are disposed a liquid poison tank, a pressurizing source, a pressure control valve, a liquid level meter and the like. The control for the reactor power is conducted by controlling the level of the liquid poisons in the control tubes. (Ikeda, J.)

  7. Human Powered PiezoelectricBatteries to Supply Power to Wearable Electronic Devices.

    OpenAIRE

    Gonzalez, Jose' Luis; Rubio, Antonio; Moll, Francesc

    2002-01-01

    Consumer electronic equipments are becoming small, portable devices that provide users with a wide range of functionality, from communication to music playing. The battery technology and the power consumption of the device limit the size, weight and autonomous lifetime. One promising alternative to batteries (and fuel cells, that must be refueled as well) is to use the parasitic energy dissipated in the movement of the wearer of the device to power it. We analyze in this work the current stat...

  8. A SiC MOSFET Power Module With Integrated Gate Drive for 2.5 MHz Class E Resonant Converters

    DEFF Research Database (Denmark)

    Jørgensen, Asger Bjørn; Nair, Unnikrishnan Raveendran; Munk-Nielsen, Stig

    2018-01-01

    Industrial processes are still relying on high frequency converters based on vacuum tubes. Emerging silicon carbide semiconductor devices have potential to replace vacuum tubes and bring benefits for converters in the high frequency range. At high switching frequencies hard-switched gate drivers...

  9. The Benefits of SiC MOSFETs in a T-Type Inverter for Grid-Tie Applications

    DEFF Research Database (Denmark)

    Anthon, Alexander; Zhang, Zhe; Andersen, Michael A. E.

    2016-01-01

    at the expense of increased switching losses since these outer switches must now block the full DC link voltage. Silicon Carbide (SiC) MOSFET devices potentially offer substantial advantage in this context with their lower switching losses, but the benefit of replacing all switching devices in a T-Type inverter...... with SiC MOSFETs is not so clear-cut. This paper now explores this issue by presenting a detailed comparison of the use of Si and SiC devices for a three-level T-Type inverter operating in grid-tie applications. The study uses datasheet values, switching loss measurements and calibrated heat sink thermal...... power level or the switching frequency to be significantly increased for the same device losses. Hence the use of SiC MOSFETS for T-Type inverters can be seen to be an attractive and potentially cost effective alternative, since only two switching devices per phase leg need to be upgraded....

  10. System Control Applications of Low-Power Radio Frequency Devices

    Science.gov (United States)

    van Rensburg, Roger

    2017-09-01

    This paper conceptualizes a low-power wireless sensor network design for application employment to reduce theft of portable computer devices used in educational institutions today. The aim of this study is to design and develop a reliable and robust wireless network that can eradicate accessibility of a device’s human interface. An embedded system supplied by an energy harvesting source, installed on the portable computer device, may represent one of multiple slave nodes which request regular updates from a standalone master station. A portable computer device which is operated in an undesignated area or in a field perimeter where master to slave communication is restricted, indicating a possible theft scenario, will initiate a shutdown of its operating system and render the device unusable. Consequently, an algorithm in the device firmware may ensure the necessary steps are executed to track the device, irrespective whether the device is enabled. Design outcomes thus far indicate that a wireless network using low-power embedded hardware, is feasible for anti-theft applications. By incorporating one of the latest Bluetooth low-energy, ANT+, ZigBee or Thread wireless technologies, an anti-theft system may be implemented that has the potential to reduce major portable computer device theft in institutions of digitized learning.

  11. Characterization and Mitigation of Radiation and High Temperature Effects in SiC Power Electronics, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Future NASA science and exploration missions require significant performance improvements over the state-of-the-art in Power Management and Distribution (PMAD)...

  12. Characterization and Mitigation of Radiation and High Temperature Effects in SiC Power Electronics, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Future NASA science and exploration missions require significant performance improvements over the state-of-the-art in Power Management and Distribution (PMAD)...

  13. Smartphone-Driven Low-Power Light-Emitting Device

    Directory of Open Access Journals (Sweden)

    Hea-Ja An

    2017-01-01

    Full Text Available Low-level light (laser therapy (LLLT has been widely researched in the recent past. Existing LLLT studies were performed based on laser. Recently, studies using LED have increased. This study presents a smartphone-driven low-power light-emitting device for use in colour therapy as an alternative medicine. The device consists of a control unit and a colour probe. The device is powered by and communicates with a smartphone using USB On-The-Go (OTG technology. The control unit controls emitting time and intensity of illumination with the configuration value of a smartphone application. Intensity is controlled by pulse width modulation (PWM without feedback. A calibration is performed to resolve a drawback of no feedback. To calibrate, intensity is measured in every 10 percent PWM output. PWM value is linearly calibrated to obtain accurate intensity. The device can control the intensity of illumination, and so, it can find application in varied scenarios.

  14. Power Factor Improvement Using Automatic Power Factor Compensation (APFC Device for Medical Industries in Malaysia

    Directory of Open Access Journals (Sweden)

    Zaidi Maryam Nabihah

    2018-01-01

    Full Text Available This paper present the project designed to correcting power factor for medical industries in Malaysia automatically. Which with hope to make the cost and energy usage efficient, because the energy source are depleting due to increase in population. Power factor is the ratio of real power and apparent power. This definition is mathematically represented as kW/kVA where kW is active power and kVA is apparent power (active + reactive. Reactive power is the non-working power generated by the magnetic and inductive load to generate magnetic flux. The increase in reactive power increase the apparent power so the power factor will decrease. Low pF will cause the industry to meet high demand thus making it less efficient. The main aim of this project is to increasing the current power factor of medical industries from 0.85 to 0.90. Power factor compensation contribute to reduction in current-dependent losses and increase energy efficiency while expanding the reliability of planning for future energy network. As technology develops, the gradual cost and efficiency penalty should reduce. Therefore, automatic power factor compensation device should become cost-effective and smaller device over time. That is the reason this project is using programmable device as it is a miniature architecture device.

  15. Repair and managing device in nuclear power plants

    International Nuclear Information System (INIS)

    Shinzawa, Katsuo.

    1982-01-01

    Purpose: To moderate the operator's labour by automatically carrying out the managing works for the repair of nuclear power plants. Constitution: Information concerning the content of the repair works inputted from an input device is arranged and analyzed in a calculation device and judged if it is the content for a format work or not. The calculation device has a function of extracting the information regarding the format work content from the memory device and comparing the plant information from the reading device before the repair work and after the recovering work. A printer connected to the output end of the calculation device issues an information regarding the format work content extracted from the memory device, that is, written work procedures and operation inhibition TAG. The content, period, person in charge, purpose, allowed items and the likes for the works are printed on the operation inhibition TAG. After the operation for the equipments, one half of them is charged to the equipment and the other half of them is charged to the reading device and the plant information is sent to the memory device. (Kawakami, Y.)

  16. Nonlinear Characterization of Half and Full Wavelength Power Ultrasonic Devices

    Science.gov (United States)

    Mathieson, Andrew; Cerisola, Niccolò; Cardoni, Andrea

    It is well known that power ultrasonic devices whilst driven under elevated excitation levels exhibit nonlinear behaviors. If no attempt is made to understand and subsequently control these behaviors, these devices can exhibit poor performance or even suffer premature failure. This paper presents an experimental method for the dynamic characterization of a commercial ultrasonic transducer for bone cutting applications (Piezosurgery® Device) operated together with a variety of rod horns that are tuned to operate in a longitudinal mode of vibration. Near resonance responses, excited via a burst sine sweep method were used to identify nonlinear responses exhibited by the devices, while experimental modal analysis was performed to identify the modal parameters of the longitudinal modes of vibration of the assemblies between 0-80 kHz. This study tries to provide an understanding of the effects that geometry and material choices may have on the nonlinear behavior of a tuned device.

  17. Oxygen isotopic exchange occurring during dry thermal oxidation of 6H SiC

    Energy Technology Data Exchange (ETDEWEB)

    Vickridge, I.C. E-mail: vickridge@gps.jussieu.fr; Tromson, D.; Trimaille, I.; Ganem, J.-J.; Szilagyi, E.; Battistig, G

    2002-05-01

    SiC is a large band gap semiconductor, promising for high power and high frequency devices. The thermal oxide is SiO{sub 2} however the growth rates of thermal oxide on SiC are substantially slower than on Si, and different along the polar directions (<0 0 0 1-bar> and <0 0 0 1> in the hexagonal polytypes). Thorough understanding of the oxide growth mechanisms may give us new insights into the nature of the SiO{sub 2}/SiC interface, crucial for device applications. We have determined growth kinetics for ultra-dry thermal oxidation of 6H SiC at 1100 deg. C for pressures from 3 to 200 mbar. At 3 mbar, the lowest pressure studied, the oxide growth rates along the two polar directions are virtually the same. At higher pressures growth is faster on the carbon-terminated (0 0 0 1-bar) face. After consecutive oxidations at 1100 deg. C and 100 mbar in {sup 18}O{sub 2} and {sup 16}O{sub 2} gases, {sup 18}O depth profiles show significant isotopic exchange and oxygen movement within the oxide during oxidation.

  18. Authenticated Encryption for Low-Power Reconfigurable Wireless Devices

    DEFF Research Database (Denmark)

    Khajuria, Samant; Andersen, Birger

    2013-01-01

    this enabling technology, these radios have to propose cryptographic services such as con- fidentiality, integrity and authentication. Therefore, integration of security services to these low-power devices is very challenging and crucial as they have limited resources and computational capabilities....... In this paper, we present a crypto solution for reconfigurable devices. The solution is a single pass Authenticated Encryption (AE) scheme that is designed for protecting both message confidentiality and its authenticity. This makes AE very attractive for low-cost low-power hardware implementation. For test...

  19. Calculation device for fuel power history in BWR type reactors

    International Nuclear Information System (INIS)

    Sakagami, Masaharu.

    1980-01-01

    Purpose: To enable calculations for power history and various variants of power change in the power history of fuels in a BWR type reactor or the like. Constitution: The outputs of the process computation for the nuclear reactor by a process computer are stored and the reactor core power distribution is judged from the calculated values for the reactor core power distribution based on the stored data. Data such as for thermal power, core flow rate, control rod position and power distribution are recorded where the changes in the power distribution exceed a predetermined amount, and data such as for thermal power and core flow rate are recorded where the changes are within the level of the predetermined amount, as effective data excluding unnecessary data. Accordingly, the recorded data are taken out as required and the fuel power history and the various variants in the fuel power are calculated and determined in a calculation device for fuel power history and variants for fuel power fluctuation. (Furukawa, Y.)

  20. Reduction of parasitic capacitance in 10 kV SiC MOSFET power modules using 3D FEM

    DEFF Research Database (Denmark)

    Jørgensen, Asger Bjørn; Christensen, Nicklas; Dalal, Dipen Narendrabhai

    2017-01-01

    The benefits of emerging wide-band gap semiconductors can only be utilized if the semiconductor is properly packaged. Capacitive coupling in the package causes electromagnetic interference during high dv/dt switching. This paper investigates the current flowing in the parasitic capacitance between...... the output node and the grounded heat sink for a custom silicon carbide power module. A circuit model of the capacitive coupling path is presented, using parasitic capacitances extracted from ANSYS Q3D. Simulated values are compared with experimental results. A new iteration of the silicon carbide power...

  1. Reactive power control of wind farm using facts devices

    International Nuclear Information System (INIS)

    Ashfaq, S.; Arif, A.; Shakeel, A.; Mahmood, T.

    2014-01-01

    Wind energy is an attainable option to complement other types of pollution-free green generation Grid connections of renewable energy resources are vital if they are to be effectively exploited, but grid connection brings problems of voltage fluctuation and harmonic distortion. FACTs devices are one of the power electronics revolutions to improve voltage profile, system stability, and reactive power control and to reduce transmission losses. The studied system here is a variable speed wind generation system based on Induction Generator (IG) with integration of different FACTs controllers in the wind farm. To harness the wind power efficiently the most reliable and expensive system in the present era is grid connected doubly fed induction generator. Induction generator with FACTs devices is a suitable economical replacement. The suggested scheme is implemented in MATLAB Simulink with real time parameters of GHARO wind power plant in Sind, and corresponding results and output waveforms proves the potential strength of proposed methodology. (author)

  2. Local wall power loading variations in thermonuclear fusion devices

    International Nuclear Information System (INIS)

    Carroll, M.C.; Miley, G.H.

    1989-01-01

    A 2 1/2-dimensional geometric model is presented that allows calculation of power loadings at various points on the first wall of a thermonuclear fusion device. Given average wall power loadings for brems-strahlung, cyclotron radiation charged particles, and neutrons, which are determined from various plasma-physics computation models, local wall heat loads are calculated by partitioning the plasma volume and surface into cells and superimposing the heating effects of the individual cells on selected first-wall differential areas. Heat loads from the entire plasma are thus determined as a function of position on the first-wall surface. Significant differences in local power loadings were found for most fusion designs, and it was therefore concluded that the effect of local power loading variations must be taken into account when calculating temperatures and heat transfer rates in fusion device first walls

  3. Low Power Design for Future Wearable and Implantable Devices

    Directory of Open Access Journals (Sweden)

    Katrine Lundager

    2016-10-01

    Full Text Available With the fast progress in miniaturization of sensors and advances in micromachinery systems, a gate has been opened to the researchers to develop extremely small wearable/implantable microsystems for different applications. However, these devices are reaching not to a physical limit but a power limit, which is a critical limit for further miniaturization to develop smaller and smarter wearable/implantable devices (WIDs, especially for multi-task continuous computing purposes. Developing smaller and smarter devices with more functionality requires larger batteries, which are currently the main power provider for such devices. However, batteries have a fixed energy density, limited lifetime and chemical side effect plus the fact that the total size of the WID is dominated by the battery size. These issues make the design very challenging or even impossible. A promising solution is to design batteryless WIDs scavenging energy from human or environment including but not limited to temperature variations through thermoelectric generator (TEG devices, body movement through Piezoelectric devices, solar energy through miniature solar cells, radio-frequency (RF harvesting through antenna etc. However, the energy provided by each of these harvesting mechanisms is very limited and thus cannot be used for complex tasks. Therefore, a more comprehensive solution is the use of different harvesting mechanisms on a single platform providing enough energy for more complex tasks without the need of batteries. In addition to this, complex tasks can be done by designing Integrated Circuits (ICs, as the main core and the most power consuming component of any WID, in an extremely low power mode by lowering the supply voltage utilizing low-voltage design techniques. Having the ICs operational at very low voltages, will enable designing battery-less WIDs for complex tasks, which will be discussed in details throughout this paper. In this paper, a path towards battery

  4. Thermal Loading and Lifetime Estimation for Power Device Considering Mission Profiles in Wind Power Converter

    DEFF Research Database (Denmark)

    Ma, Ke; Liserre, Marco; Blaabjerg, Frede

    2015-01-01

    for the reliability improvement and also for cost reduction of wind power technology. Unfortunately, the existing lifetime estimation methods for the power electronic converter are not yet suitable in the wind power application, because the comprehensive mission profiles are not well specified and included......As a key component in the wind turbine system, the power electronic converter and its power semiconductors suffer from complicated power loadings related to environment, and are proven to have high failure rates. Therefore, correct lifetime estimation of wind power converter is crucial...... devices, more detailed information of the lifetime-related performance in wind power converter can be obtained. Some experimental results are also included to validate the thermal behavior of power device under different mission profiles....

  5. Advances in wide bandgap SiC for optoelectronics

    DEFF Research Database (Denmark)

    Ou, Haiyan; Ou, Yiyu; Argyraki, Aikaterini

    2014-01-01

    Silicon carbide (SiC) has played a key role in power electronics thanks to its unique physical properties like wide bandgap, high breakdown field, etc. During the past decade, SiC is also becoming more and more active in optoelectronics thanks to the progress in materials growth and nanofabrication...

  6. Power density forecasting device for nuclear power plant

    International Nuclear Information System (INIS)

    Fukuzaki, Takaharu; Kiguchi, Takashi.

    1978-01-01

    Purpose: To attain effective reactor operation in a bwr type reactor by forecasting the power density of the reactor after adjustment and comparing the same with the present status of the reactor by the on-line calculation in a short time. Constitution: The present status for the reactor is estimated in a present status decision section based on a measurement signal from the reactor and it is stored in an operation result collection section. The reactor status after the forecasting is estimated in a forecasting section based on a setting signal from a forecasting condition setting section and it is compared with the result value from the operation results collection section. If the forecast value does not coincide with the result value in the above comparison, the setting value in the forecast condition setting section is changed in the control section. The above procedures are repeated so as to minimize the difference between the forecast value and the result value to thereby exactly forecast the reactor status and operate the reactor effectively. (Moriyama, K.)

  7. Compact electro-thermal modeling of a SiC MOSFET power module under short-circuit conditions

    DEFF Research Database (Denmark)

    Ceccarelli, Lorenzo; Reigosa, Paula Diaz; Bahman, Amir Sajjad

    2017-01-01

    A novel physics-based, electro-thermal model which is capable of estimating accurately the short-circuit behavior and thermal instabilities of silicon carbide MOSFET multi-chip power modules is proposed in this paper. The model has been implemented in PSpice and describes the internal structure.......2 kV breakdown voltage and about 300 A rated current. The short-circuit behavior of the module is investigated experimentally through a non-destructive test setup and the model is validated. The estimation of overcurrent and temperature distribution among the chips can provide useful information...

  8. Reactive power planning with FACTS devices using gravitational search algorithm

    Directory of Open Access Journals (Sweden)

    Biplab Bhattacharyya

    2015-09-01

    Full Text Available In this paper, Gravitational Search Algorithm (GSA is used as optimization method in reactive power planning using FACTS (Flexible AC transmission system devices. The planning problem is formulated as a single objective optimization problem where the real power loss and bus voltage deviations are minimized under different loading conditions. GSA based optimization algorithm and particle swarm optimization techniques (PSO are applied on IEEE 30 bus system. Results show that GSA can also be a very effective tool for reactive power planning.

  9. Experimental Study of a Multi Level Overtopping Wave Power Device

    DEFF Research Database (Denmark)

    Kofoed, Jens Peter; Hald, Tue; Frigaard, Peter Bak

    2002-01-01

    Results of experimental investigations of a floating wave energy device called Power Pyramid is presented. The Power Pyramid utilizes reservoirs in multiple levels when capturing wave overtopping and converting it into electrical energy. The effect of capturing the overtopping in multiple levels,......, using 5 levels introduces practical problems, and is most probably not economically feasible. It is concluded that it is reasonable to use 2 levels (maybe 3), which can increase the efficiency by 25-40 % compared to using a single level.......Results of experimental investigations of a floating wave energy device called Power Pyramid is presented. The Power Pyramid utilizes reservoirs in multiple levels when capturing wave overtopping and converting it into electrical energy. The effect of capturing the overtopping in multiple levels......, compared to only one level, has been evaluated experimentally. From the experimental results, and the performed optimizations based on these, it has been found that the efficiency of a wave power device of the overtopping type can be increased by as much as 76 % by using 5 levels instead of 1. However...

  10. Development of PSpice modeling platform for 10 kV/100 A SiC MOSFET power module

    DEFF Research Database (Denmark)

    Martins, Joäo Pedro Rodrigues; Nawaz, Muhammad; Ilves, Kalle

    2017-01-01

    was implemented based on the already established McNutt Hefner model originally developed for discrete single-die based SiC-MOSFETs. The proposed model has been verified both with static and dynamic experimental data and at different temperatures. Moreover, the energy loss assessment has been performed...... for a variety of operating parameters (e.g., stray inductance, gate resistance), different load current and supply voltages. The model was also verified with parallel connection of several power modules in order to predict the current unbalance as a result of various parasitic elements in the test circuit....... The developed model has been further extended to study the electro-thermal behaviour under short circuit with accurate predictability, and validated with the experimental data. Finally, the operational robustness of the model was judged by simulating an arbitrary Buck, and Boost converter where the converter...

  11. Device for measuring active, reactive and apparent power

    Energy Technology Data Exchange (ETDEWEB)

    Bartosinski, E.; Wieland, J.

    1982-09-30

    The plan consists of a traditional electrodynamic mechanism for measuring power (IM) supplemented by three switches, two rectifiers, resistor, included in parallel, and phaseshifting throttle included in series with the voltage coil of the IM. This makes it possible by selection to perform three types of measurements: active power of alternating current or power of direct current, only the voltage coils and the IM current are engaged; reactive power, the resistor and the throttle are additionally engaged by the aforementioned method; complete (apparent) power--the current and the voltage are supplied directly to the IM coils, but in contrast to the first case, through rectifiers. The influence of the highest harmonic components of voltage and current which are not significant for industrial measurements can be eliminated in necessary cases using filtering devices.

  12. New constructions of approximately SIC-POVMs via difference sets

    Science.gov (United States)

    Luo, Gaojun; Cao, Xiwang

    2018-04-01

    In quantum information theory, symmetric informationally complete positive operator-valued measures (SIC-POVMs) are related to quantum state tomography (Caves et al., 2004), quantum cryptography (Fuchs and Sasaki, 2003) [1], and foundational studies (Fuchs, 2002) [2]. However, constructing SIC-POVMs is notoriously hard. Although some SIC-POVMs have been constructed numerically, there does not exist an infinite class of them. In this paper, we propose two constructions of approximately SIC-POVMs, where a small deviation from uniformity of the inner products is allowed. We employ difference sets to present the first construction and the dimension of the approximately SIC-POVMs is q + 1, where q is a prime power. Notably, the dimension of this framework is new. The second construction is based on partial geometric difference sets and works whenever the dimension of the framework is a prime power.

  13. Power Cycling Test Method for Reliability Assessment of Power Device Modules in Respect to Temperature Stress

    DEFF Research Database (Denmark)

    Choi, Ui-Min; Blaabjerg, Frede; Jørgensen, Søren

    2018-01-01

    Power cycling test is one of the important tasks to investigate the reliability performance of power device modules in respect to temperature stress. From this, it is able to predict the lifetime of a component in power converters. In this paper, representative power cycling test circuits......, measurement circuits of wear-out failure indicators as well as measurement strategies for different power cycling test circuits are discussed in order to provide the current state of knowledge of this topic by organizing and evaluating current literature. In the first section of this paper, the structure...... of a conventional power device module and its related wear-out failure mechanisms with degradation indicators are discussed. Then, representative power cycling test circuits are introduced. Furthermore, on-state collector-emitter voltage (VCE ON) and forward voltage (VF) measurement circuits for wear-out condition...

  14. Low power signal processing electronics for wearable medical devices.

    Science.gov (United States)

    Casson, Alexander J; Rodriguez-Villegas, Esther

    2010-01-01

    Custom designed microchips, known as Application Specific Integrated Circuits (ASICs), offer the lowest possible power consumption electronics. However, this comes at the cost of a longer, more complex and more costly design process compared to one using generic, off-the-shelf components. Nevertheless, their use is essential in future truly wearable medical devices that must operate for long periods of time from physically small, energy limited batteries. This presentation will demonstrate the state-of-the-art in ASIC technology for providing online signal processing for use in these wearable medical devices.

  15. Power supply for magnetic coils in thermonuclear devices

    International Nuclear Information System (INIS)

    Shimada, Ryuichi; Tamura, Sanae; Kishimoto, Hiroshi.

    1981-01-01

    Purpose: To decrease the load fluctuations in an external power supply, as well as to increase the operation efficiency capacity of thermonuclear devices. Constitution: Electrical power with the same frequency as that of a dynamo generator is supplied by a power supply-driving power source including a frequency converter and the like to DC converters for driving plasma-exciting and -controlling coils. At the same time, the electrical power from the frequency converter is supplied to the dynamo generator with flywheel to add accumulate energies to the EC converters. Accordingly, the energy for the great power pulses in a short time comprises the sum of the energy supplied from the dynamo generator with flywheel and the energy supplied continuously from the outside to eliminate the need of providing a stand-by period for the re-acceleration of the dynamo generator with flywheel even if the scale of the thermonuclear device is enlarged and energy consumed in one cycle is increased, whereby the decrease in the operation efficiency can be prevented and the capacity of the flywheel can be reduced. (Yoshino, Y.)

  16. Advanced, High Power, Next Scale, Wave Energy Conversion Device

    Energy Technology Data Exchange (ETDEWEB)

    Mekhiche, Mike [Principal Investigator; Dufera, Hiz [Project Manager; Montagna, Deb [Business Point of Contact

    2012-10-29

    The project conducted under DOE contract DE‐EE0002649 is defined as the Advanced, High Power, Next Scale, Wave Energy Converter. The overall project is split into a seven‐stage, gated development program. The work conducted under the DOE contract is OPT Stage Gate III work and a portion of Stage Gate IV work of the seven stage product development process. The project effort includes Full Concept Design & Prototype Assembly Testing building on our existing PowerBuoy technology to deliver a device with much increased power delivery. Scaling‐up from 150kW to 500kW power generating capacity required changes in the PowerBuoy design that addressed cost reduction and mass manufacturing by implementing a Design for Manufacturing (DFM) approach. The design changes also focused on reducing PowerBuoy Installation, Operation and Maintenance (IO&M) costs which are essential to reducing the overall cost of energy. In this design, changes to the core PowerBuoy technology were implemented to increase capability and reduce both CAPEX and OPEX costs. OPT conceptually envisaged moving from a floating structure to a seabed structure. The design change from a floating structure to seabed structure would provide the implementation of stroke‐ unlimited Power Take‐Off (PTO) which has a potential to provide significant power delivery improvement and transform the wave energy industry if proven feasible.

  17. Method and device for controlling nuclear reactor power

    International Nuclear Information System (INIS)

    Takigawa, Yukio; Ebata, Shigeo.

    1988-01-01

    Purpose: To detect and suppress the special power oscillations in the reactor core. Method: Four pairs of LPRM detectors, each pair comprising two detectors are disposed at an identical axial direction of the reactor core and situated at substantially insymmetrical positions at least in longitudinal, vertical and orthogonal directions with respect to the center of te reactor core and LPRM signals from them are inputted into a device for judging special power oscillations. In this case, a standardized mutual relation function is determined on every pair for the respective LPRM signals. Generation of special power oscillations in the reactor core is judged when it is detected that peaks appearing at least in one of the function forms for each pair are negative and have absolute values exceeding a predetermined value and that time of peak is within a predetermined time. The judged signal is inputted to a selected control rod insertion device. The selected control rod insertion device, upon preceiving the signal, inserts selected control rods into the reactor core to suppress the special power oscillations. Accordingly, it is possible to improve the fuel integrity. (Horiuchi, T.)

  18. Energy-Efficient Resource and Power Allocation for Underlay Multicast Device-to-Device Transmission

    Directory of Open Access Journals (Sweden)

    Fan Jiang

    2017-11-01

    Full Text Available In this paper, we present an energy-efficient resource allocation and power control scheme for D2D (Device-to-Device multicasting transmission. The objective is to maximize the overall energy-efficiency of D2D multicast clusters through effective resource allocation and power control schemes, while considering the quality of service (QoS requirements of both cellular users (CUs and D2D clusters. We first build the optimization model and a heuristic resource and power allocation algorithm is then proposed to solve the energy-efficiency problem with less computational complexity. Numerical results indicate that the proposed algorithm outperforms existing schemes in terms of throughput per energy consumption.

  19. The Development of a Hybrid-Type Radiation Detector with SiC for a Reactor Robot

    International Nuclear Information System (INIS)

    Lee, Nam Ho; Cho, Jai Wan; Kim, Seung Ho

    2005-01-01

    For a robot working in a harsh environment such as a nuclear reactor environment or a space environment, requirements of on-board radiation detectors are not the same as those for environments around human. SiC devices with the wide band-gap are less dependent on temperature than Si counterparts and the can be the better candidate for the high radiation environment. With this background, radiation performance of a commercial SiC detector in a Co-60 gamma-ray environment has been evaluated. In addition to the SiC detector, a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) detector has been incorporated as a backup. With this MOSFET sensor the dosimeter can keep its radiation exposure history even with loss of power. It is not only a redundant feature but also a diverse feature. The dosimetry module can be attached to mobile robot for high radiation environment was developed. This module has both SiC diode and pMOSFET mentioned above. The monitoring program which receives the radiation information from them and gives out the alarm signal when the difference of the two values from them is over the preset level was constructed. Because both the SiC pulse-type detector and the MOSFET dosimeter are small and light weight, they can be easily accommodated on a small printcircuit board for a tight space on a robot arm or for a small spacecraft

  20. THORs Power Method for Hydrokinetic Devices - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    J. Turner Hunt; Joel Rumker

    2012-08-08

    Ocean current energy represents a vast untapped source of renewable energy that exists on the outer continental shelf areas of the 5 major continents. Ocean currents are unidirectional in nature and are perpetuated by thermal and salinity sea gradients, as well as coriolis forces imparted from the earth's rotation. This report details THORs Power Method, a breakthrough power control method that can provide dramatic increases to the capacity factor over and above existing marine hydrokinetic (MHK) devices employed in the extraction of energy from ocean currents. THORs Power Method represents a constant speed, variable depth operational method that continually locates the ocean current turbine at a depth at which the rated power of the generator is routinely achieved. Variable depth operation is achieved by using various vertical force effectors, including ballast tanks for variable weight, a hydrodynamic wing for variable lift or down force and drag flaps for variable vehicle drag forces.

  1. After-heat removing device in nuclear power plant

    Energy Technology Data Exchange (ETDEWEB)

    Mizuno, K [Nippon Atomic Industry Group Co. Ltd., Tokyo

    1977-01-14

    Purpose: To prevent water hammer in a BWR type reactor or the like by moving water in pipe lines having stagnant portions in an after-heat removing device. Constitution: To a reactor container, is provided a recycling pump which constitutes a closed loop type recycling system in a nuclear power plant together with a pressure vessel and pipe lines. A pump and a heat exchanger are provided outside of the reactor container and they are connected to up- and down-streams of the recycling pump to form an after-heat removing device in the plant. Upon shutdown of the nuclear power plant, since water in the stagnant portion flows to the intake port of the recycling pump and water from the reactor is spontaneously supplemented thereafter to the stagnant portion, neither pressurized water nor heated steam is generated and thus water hammer is prevented.

  2. Low-power signal processing devices for portable ECG detection.

    Science.gov (United States)

    Lee, Shuenn-Yuh; Cheng, Chih-Jen; Wang, Cheng-Pin; Kao, Wei-Chun

    2008-01-01

    An analog front end for diagnosing and monitoring the behavior of the heart is presented. This sensing front end has two low-power processing devices, including a 5(th)-order Butterworth operational transconductance-C (OTA-C) filter and an 8-bit successive approximation analog-to-digital converter (SAADC). The components fabricated in a 0.18-microm CMOS technology feature with power consumptions of 453 nW (filter) and 940 nW (ADC) at a supply voltage of 1 V, respectively. The system specifications in terms of output noise and linearity associated with the two integrated circuits are described in this paper.

  3. The 'CETO' wave power generation devices

    Energy Technology Data Exchange (ETDEWEB)

    Profitt, Michael

    2007-07-01

    Renewable Energy Holdings plc (REH) is an international company established to be an operator of, and undertake active investments in both proven and innovative renewable energy technologies. The CETO devices have been developed in Western Australia by Seapower Pacific PTY Ltd (SPPL), a subsidiary of Renewable Energy Holdings Plc (REH). This paper reports on the technology and also includes the findings from an independent technical appraisal undertaken by PB Power. The CETO device consists primarily of a novel pump anchored to the seabed and driven by a spherical buoyant actuator that collects wave energy and transmits it to the pump. High pressure seawater is delivered ashore where it can be used to drive a turbine to generate electricity or passed through a reverse osmosis desalination unit to produce fresh water. The competitive edge of CETO against other current wave and tidal generation devices: Electricity generated onshore (using well-proven hydro-power technology); Low cost mass produced device; Simplified infrastructure from pumping pressurised sea water ashore rather than electricity; Allows shore-based desalination; Modular design and self deployment; and, Transport in standard containers.

  4. Demonstration of a 4H SiC betavoltaic nuclear battery based on Schottky barrier diode

    International Nuclear Information System (INIS)

    Qiao Dayong; Yuan Weizheng; Gao Peng; Yao Xianwang; Zang Bo; Zhang Lin; Guo Hui; Zhang Hongjian

    2008-01-01

    A 4H SiC betavoltaic nuclear battery is demonstrated. A Schottky barrier diode is utilized for carrier separation. Under illumination of Ni-63 source with an apparent activity of 4 mCi/cm 2 an open circuit voltage of 0.49 V and a short circuit current density of 29.44 nA/cm 2 are measured. A power conversion efficiency of 1.2% is obtained. The performance of the device is limited by low shunt resistance, backscattering and attenuation of electron energy in air and Schottky electrode. It is expected to be significantly improved by optimizing the design and processing technology of the device. (authors)

  5. Demonstration of a 4H SiC Betavoltaic Nuclear Battery Based on Schottky Barrier Diode

    International Nuclear Information System (INIS)

    Da-Yong, Qiao; Wei-Zheng, Yuan; Peng, Gao; Xian-Wang, Yao; Bo, Zang; Lin, Zhang; Hui, Guo; Hong-Jian, Zhang

    2008-01-01

    A 4H SiC betavoltaic nuclear battery is demonstrated. A Schottky barrier diode is utilized for carrier separation. Under illumination of Ni-63 source with an apparent activity of 4 mCi/cm 2 an open circuit voltage of 0.49 V and a short circuit current density of 29.44 nA/cm 2 are measured. A power conversion efficiency of 1.2% is obtained. The performance of the device is limited by low shunt resistance, backscattering and attenuation of electron energy in air and Schottky electrode. It is expected to be significantly improved by optimizing the design and processing technology of the device

  6. Asymmetric power device rating selection for even temperature distribution in NPC inverter

    DEFF Research Database (Denmark)

    Choi, Uimin; Blaabjerg, Frede

    2017-01-01

    the power rating and lifetime of the NPC inverter are limited by the most stressed devices. In this paper, an asymmetric power device rating selection method for the NPC inverter is proposed in order to balance the lifetimes of the power devices. The thermal distribution of the power devices is analyzed......A major drawback of the NPC inverter is an unequal power loss distribution among the power devices which leads to unequal temperature stress among them. Therefore, certain power devices experience higher temperature stress, which is the main cause of power device module failure and thus both...... based on 30 kW NPC inverter as a case study. Analytical power loss and thermal impedance models depending on the chip size are derived. Finally, using these models, the junction temperatures of the power devices depending on the chip size is discussed and a proper chip size for an even temperature...

  7. Power Packaging of Spray-Cooled SiC Devices for High Temperature and High Voltage Operation: Final Report

    Science.gov (United States)

    2008-07-01

    the desired switching frequencies. * I Three- r1aL phase dc-ac ac-dc Vph converter # 4 convertr converter 1 # 2 # 3 * I r --- -- -- - 4I6l kV ACSIDE...J:-----------------.HWn.XEMEL ------- J WDC_ SI CEI.................... ... .. .. .............. .......... J . Fig. 4.1 Block diagram of a PCM4. Vph

  8. High density plasma via hole etching in SiC

    International Nuclear Information System (INIS)

    Cho, H.; Lee, K.P.; Leerungnawarat, P.; Chu, S.N.G.; Ren, F.; Pearton, S.J.; Zetterling, C.-M.

    2001-01-01

    Throughwafer vias up to 100 μm deep were formed in 4H-SiC substrates by inductively coupled plasma etching with SF 6 /O 2 at a controlled rate of ∼0.6 μm min-1 and use of Al masks. Selectivities of >50 for SiC over Al were achieved. Electrical (capacitance-voltage: current-voltage) and chemical (Auger electron spectroscopy) analysis techniques showed that the etching produced only minor changes in reverse breakdown voltage, Schottky barrier height, and near surface stoichiometry of the SiC and had high selectivity over common frontside metallization. The SiC etch rate was a strong function of the incident ion energy during plasma exposure. This process is attractive for power SiC transistors intended for high current, high temperature applications and also for SiC micromachining

  9. Channel Access and Power Control for Mobile Crowdsourcing in Device-to-Device Underlaid Cellular Networks

    Directory of Open Access Journals (Sweden)

    Yue Ma

    2018-01-01

    Full Text Available With the access of a myriad of smart handheld devices in cellular networks, mobile crowdsourcing becomes increasingly popular, which can leverage omnipresent mobile devices to promote the complicated crowdsourcing tasks. Device-to-device (D2D communication is highly desired in mobile crowdsourcing when cellular communications are costly. The D2D cellular network is more preferable for mobile crowdsourcing than conventional cellular network. Therefore, this paper addresses the channel access and power control problem in the D2D underlaid cellular networks. We propose a novel semidistributed network-assisted power and a channel access control scheme for D2D user equipment (DUE pieces. It can control the interference from DUE pieces to the cellular user accurately and has low information feedback overhead. For the proposed scheme, the stochastic geometry tool is employed and analytic expressions are derived for the coverage probabilities of both the cellular link and D2D links. We analyze the impact of key system parameters on the proposed scheme. The Pareto optimal access threshold maximizing the total area spectral efficiency is obtained. Unlike the existing works, the performances of the cellular link and D2D links are both considered. Simulation results show that the proposed method can improve the total area spectral efficiency significantly compared to existing schemes.

  10. Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices

    Science.gov (United States)

    Chassin, David P [Pasco, WA; Donnelly, Matthew K [Kennewick, WA; Dagle, Jeffery E [Richland, WA

    2011-12-06

    Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices are described. In one aspect, an electrical power distribution control method includes providing electrical energy from an electrical power distribution system, applying the electrical energy to a load, providing a plurality of different values for a threshold at a plurality of moments in time and corresponding to an electrical characteristic of the electrical energy, and adjusting an amount of the electrical energy applied to the load responsive to an electrical characteristic of the electrical energy triggering one of the values of the threshold at the respective moment in time.

  11. SUBWAY POWER SYSTEMS WITH MODERN SEMICONDUCTOR CONVERTERS AND ENERGY STORAGE DEVICES

    Directory of Open Access Journals (Sweden)

    O.I. Kholod

    2013-02-01

    Full Text Available Five subway power systems, a traditional power system and power systems with an active rectifier and an energy storage device, are considered. Estimation of energy loss in the analyzed subway power systems circuits is made.

  12. Turbine protecting device in a BWR type nuclear power plant

    International Nuclear Information System (INIS)

    Kasuga, Hajime; Oka, Yoko.

    1984-01-01

    Purpose: To prevent highly humid steams from flowing into the turbine upon abnormal reduction in the reactor water level in order to ensure the turbine soundness, as well as in order to trip the turbine with no undesired effect on the reactor. Constitution: A protection device comprising a judging device and a timer are disposed in a BWR type reactor, in order to control a water level signal from a reactor water level gage. If the reactor water level is reduced during rated power operation, steams are kept to be generated due to decay heat although reactor is scramed. When a signal from the reactor water level detector is inputted to the protection device, a trip signal is outputted by way of a judging device after 15 second by means of the timer, when the main steam check valve is closed to trip the turbine. With this delay of time, abrupt increase in the pressure of the reactor due to sudden shutdown can be prevented. (Nakamoto, H)

  13. A wirelessly powered microspectrometer for neural probe-pin device

    Science.gov (United States)

    Choi, Sang H.; Kim, Min H.; Song, Kyo D.; Yoon, Hargsoon; Lee, Uhn

    2015-12-01

    Treatment of neurological anomalies, whether done invasively or not, places stringent demands on device functionality and size. We have developed a micro-spectrometer for use as an implantable neural probe to monitor neuro-chemistry in synapses. The micro-spectrometer, based on a NASA-invented miniature Fresnel grating, is capable of differentiating the emission spectra from various brain tissues. The micro-spectrometer meets the size requirements, and is able to probe the neuro-chemistry and suppression voltage typically associated with a neural anomaly. This neural probe-pin device (PPD) is equipped with wireless power technology (WPT) to enable operation in a continuous manner without requiring an implanted battery. The implanted neural PPD, together with a neural electronics interface and WPT, enable real-time measurement and control/feedback for remediation of neural anomalies. The design and performance of the combined PPD/WPT device for monitoring dopamine in a rat brain will be presented to demonstrate the current level of development. Future work on this device will involve the addition of an embedded expert system capable of performing semi-autonomous management of neural functions through a routine of sensing, processing, and control.

  14. High Efficiency Three-phase Power Factor Correction Rectifier using Wide Band-Gap Devices

    DEFF Research Database (Denmark)

    Kouchaki, Alireza

    Improving the conversion efficiency of power factor correction (PFC) rectifiers has become compelling due to their wide applications such as adjustable speed drives, uninterruptible power supplies (UPS), and battery chargers for electric vehicles (EVs). The attention to PFCs has increased even more....... Therefore, current controllers are also important to be investigated in this project. In this PhD research work, a comprehensive design of a two-level three-phase PFC rectifier using silicon-carbide (SiC) switches to achieve high efficiency is presented. The work is divided into two main parts: 1) Optimum...

  15. Harmonics in Offshore Wind Power Plants Employing Power Electronic Devices in the Transmission System

    DEFF Research Database (Denmark)

    Glasdam, Jakob Bærholm

    Introduction The trend in power generation is to partly replace conventional power plants with renewable energy sources. Offshore wind power has been selected to take up a significant proportion of the renewable energy production. The grid codes have been updated to accommodate the rising share...... of wind power. The onshore as well as offshore wind power plants (OWPPs) therefore have to meet the same stringent requirement as the conventional power plants. This can be accommodated by employment of flexible alternating current transmission system (FACTS) devices, such as the static compensator...... gives rise to a number of challenges to the wind power industry with regard to construction, installation as well as transmission of the generated energy. The STATCOM and the voltage-sourced converter high-voltage direct current (VSC-HVDC) are attractive solutions for grid connection of remotely located...

  16. Energetic Combustion Devices for Aerospace Propulsion and Power

    Science.gov (United States)

    Litchford, Ron J.

    2000-01-01

    Chemical reactions have long been the mainstay thermal energy source for aerospace propulsion and power. Although it is widely recognized that the intrinsic energy density limitations of chemical bonds place severe constraints on maximum realizable performance, it will likely be several years before systems based on high energy density nuclear fuels can be placed into routine service. In the mean time, efforts to develop high energy density chemicals and advanced combustion devices which can utilize such energetic fuels may yield worthwhile returns in overall system performance and cost. Current efforts in this vein are being carried out at NASA MSFC under the direction of the author in the areas of pulse detonation engine technology development and light metals combustion devices. Pulse detonation engines are touted as a low cost alternative to gas turbine engines and to conventional rocket engines, but actual performance and cost benefits have yet to be convincingly demonstrated. Light metal fueled engines also offer potential benefits in certain niche applications such as aluminum/CO2 fueled engines for endo-atmospheric Martian propulsion. Light metal fueled MHD generators also present promising opportunities with respect to electric power generation for electromagnetic launch assist. This presentation will discuss the applications potential of these concepts with respect to aero ace propulsion and power and will review the current status of the development efforts.

  17. Solar power generating device. Solar denryoku hassei sochi

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, E

    1990-02-06

    Concerning the existing solar power generating device using the analogue sequential partial shunt system, the number of interface line between the solar cell panel and the shunt dissipater is enormous and complicated in addition to the increased temperature rise of the shunt transistor in its working condition. Furthermore, concerning the digital sequential full shunt system, the above temperature rise becomes less, but the above number of interface line is likewise enormous. In order to remove the above defects, the solar power generating device which this invention concerns has the features that, in each row of solar cells connected to shunt transistors which are controlled respectively in a manner of on (saturation)/off independently in accordance with the amount of surplus electric power, the number of parallel connection of the unit cell circuits composing the each row above is made to be the different number respectively. Besides, it is proposed to have the feature in particular that such a number is made to be the number of 2 {sup n} (n is from zero to any integer, m) where n is increased by one progressively. 5 figs.

  18. Floor surface decontaminating device for use in nuclear power plants

    International Nuclear Information System (INIS)

    Yoshida, Tomiji; Ue, Tatsuyuki; Omori, Nobuya; Okuzawa, Tsutomu.

    1987-01-01

    Purpose: To obtain a device for decontaminating the floor surfaces contaminated with radioactive materials in nuclear power plants or the likes, mechanically, automatically and effectively. Constitution: During running of the device by means of running wheels and castors, a decontaminating head is always applied with vibrations by a vibrator. In this state, wiping members are sent from a delivery roll, applied with vibrations at the decontaminating head. The members wipe off contamination products while in frictional contact with the floor surface and are then taken up to a winding roll with the contamination products deposited thereto. In this case, since the vibrations from the decontaminating head are transmitted by way of a resilient portion thereof to the wiping members, the vibrations transmitted from the wiping members to the floor surface are somewhat buffered. (Kawakami, Y.)

  19. Water quality monitoring device for nuclear power plant

    International Nuclear Information System (INIS)

    Kubo, Mitsushi.

    1995-01-01

    The device of the present invention measures quality of feedwater after heated in a regenerative heat exchanger device of a coolant cleanup system in a BWR type reactor, to detect ions generated from organic materials decomposed at high temperature and specify the position where impurities are formed. Namely, in a power plant having a reactor coolant cleanup pipeline connected to a feedwater pipeline, a water quality measuring portion is disposed to the feedwater system at the downstream of the junction to the feedwater system pipeline. A water quality sample is taken to measure the water quality in a state where the feedwater heated by a feedwater heater and flowing to the reactor, and the cleanup coolants heated by the regenerative heat exchanger are mixed. Thus, the impurities formed at the down stream of the feedwater system pipeline, as well as the water quality including impurities decomposed in a high temperature state can be measured. (I.S.)

  20. Power Electronic Semiconductor Materials for Automotive and Energy Saving Applications – SiC, GaN, Ga2O3, and Diamond

    Science.gov (United States)

    2017-01-01

    Power electronics belongs to the future key technologies in order to increase system efficiency as well as performance in automotive and energy saving applications. Silicon is the major material for electronic switches since decades. Advanced fabrication processes and sophisticated electronic device designs have optimized the silicon electronic device performance almost to their theoretical limit. Therefore, to increase the system performance, new materials that exhibit physical and chemical properties beyond silicon need to be explored. A number of wide bandgap semiconductors like silicon carbide, gallium nitride, gallium oxide, and diamond exhibit outstanding characteristics that may pave the way to new performance levels. The review will introduce these materials by (i) highlighting their properties, (ii) introducing the challenges in materials growth, and (iii) outlining limits that need innovation steps in materials processing to outperform current technologies. PMID:29200530

  1. Power Electronic Semiconductor Materials for Automotive and Energy Saving Applications - SiC, GaN, Ga2O3, and Diamond.

    Science.gov (United States)

    Wellmann, Peter J

    2017-11-17

    Power electronics belongs to the future key technologies in order to increase system efficiency as well as performance in automotive and energy saving applications. Silicon is the major material for electronic switches since decades. Advanced fabrication processes and sophisticated electronic device designs have optimized the silicon electronic device performance almost to their theoretical limit. Therefore, to increase the system performance, new materials that exhibit physical and chemical properties beyond silicon need to be explored. A number of wide bandgap semiconductors like silicon carbide, gallium nitride, gallium oxide, and diamond exhibit outstanding characteristics that may pave the way to new performance levels. The review will introduce these materials by (i) highlighting their properties, (ii) introducing the challenges in materials growth, and (iii) outlining limits that need innovation steps in materials processing to outperform current technologies.

  2. Transmission Power Adaption for Full-Duplex Relay-Aided Device-to-Device Communication

    Directory of Open Access Journals (Sweden)

    Hui Dun

    2017-03-01

    Full Text Available Device-to-device (D2D communications bring significant improvements of spectral efficiency by underlaying cellular networks. However, they also lead to a more deteriorative interference environment for cellular users, especially the users in severely deep fading or shadowing. In this paper, we investigate a relay-based communication scheme in cellular systems, where the D2D communications are exploited to aid the cellular downlink transmissions by acting as relay nodes with underlaying cellular networks. We modeled two-antenna infrastructure relays employed for D2D relay. The D2D transmitter is able to transmit and receive signals simultaneously over the same frequency band. Then we proposed an efficient power allocation algorithm for the base station (BS and D2D relay to reduce the loopback interference which is inherent due to the two-antenna infrastructure in full-duplex (FD mode. We derived the optimal power allocation problem in closed form under the independent power constraint. Simulation results show that the algorithm reduces the power consumption of D2D relay to the greatest extent and also guarantees cellular users’ minimum transmit rate. Moreover, it also outperforms the existing half-duplex (HD relay mode in terms of achievable rate of D2D.

  3. Video coding for decoding power-constrained embedded devices

    Science.gov (United States)

    Lu, Ligang; Sheinin, Vadim

    2004-01-01

    Low power dissipation and fast processing time are crucial requirements for embedded multimedia devices. This paper presents a technique in video coding to decrease the power consumption at a standard video decoder. Coupled with a small dedicated video internal memory cache on a decoder, the technique can substantially decrease the amount of data traffic to the external memory at the decoder. A decrease in data traffic to the external memory at decoder will result in multiple benefits: faster real-time processing and power savings. The encoder, given prior knowledge of the decoder"s dedicated video internal memory cache management scheme, regulates its choice of motion compensated predictors to reduce the decoder"s external memory accesses. This technique can be used in any standard or proprietary encoder scheme to generate a compliant output bit stream decodable by standard CPU-based and dedicated hardware-based decoders for power savings with the best quality-power cost trade off. Our simulation results show that with a relatively small amount of dedicated video internal memory cache, the technique may decrease the traffic between CPU and external memory over 50%.

  4. Development of 2D and 3D transient electro-thermal computational models to predict the radiation failures in SiC-based Schottky diodes and power field-effect transistors (FETs)

    Data.gov (United States)

    National Aeronautics and Space Administration — High voltage (HV) power devices based on silicon carbide (SiC) semiconductor material may offer revolutionary transformations for future NASA space missions, due to...

  5. Integration of Pneumatic Technology in Powered Mobility Devices.

    Science.gov (United States)

    Daveler, Brandon; Wang, Hongwu; Gebrosky, Benjamin; Grindle, Garrett G; Schneider, Urs; Cooper, Rory A

    2017-01-01

    Advances in electric motors, electronics, and control systems have enhanced the capability and drivability of electric power mobility devices over the last 60 years. Yet, battery technologies used in powered mobility devices (PMDs) have not kept pace. Recent advances in pneumatic technology, primarily the high torque, low speed design of rotary piston air motors, directly align with the needs of PMD. Pneumatic technology has advantages over battery-powered technology, including lighter weight, lower operating costs, decreased environmental impact, better reliability, and increased safety. Two prototypes were created that incorporated rotary piston air motors, high-pressure air tanks, and air-pressure regulators. Prototype 1 was created by modifying an existing electric PMD. Range tests were performed to determine the feasibility of pneumatic technology and the optimal combination of components to allow the longest range possible at acceptable speeds over ideal conditions. Using a 1.44 L air tank for feasibility testing, prototype 1 was capable of traveling 800 m, which confirmed the feasibility of pneumatic technology usage in PMDs. Prototype 2 was designed based on the testing results from prototype 1. After further optimization of prototype 2, the average maximum range was 3,150 m. Prototype 2 is up to 28.3% lighter than an equivalent size electric PMD and can be fully recharged in approximately 2 minutes. It decreases the cost of PMDs by approximately $1,500, because batteries do not need to be replaced over the lifetime of the device. The results provide justification for the use of pneumatic technology in PMDs.

  6. Parallel Connection of Silicon Carbide MOSFETs for Multichip Power Modules

    DEFF Research Database (Denmark)

    Li, Helong

    challenges from the manufacture and application points of view. The less mature manufacture process limits the yield and the single die size of the SiC MOSFETs, which results a smaller current capability of a single SiC MOSFET die. Consequently, in high current application, the paralleled connections of Si...... connections for the paralleled dies are presented and the source of the transient current imbalance is concluded. To mitigate the transient current imbalance in the traditional DBC layout, a novel DBC layout with split output is proposed. First, the working mechanism of the split output topology is studied...... the current sharing performance among the paralleled SiC MOSFET dies in the power module. The proposed DBC layout is not only limited for SiC MOSFETs, but also for Si IGBTs and other voltage controlled devices. of the circuit mismatch on the paralleled connection of SiC MOSFETs. It reveals the circuit...

  7. Spatial and temporal instabilities in high voltage power devices

    Energy Technology Data Exchange (ETDEWEB)

    Milady, Saeed

    2010-01-29

    Dynamic avalanche can occur during the turn-off process of high voltage bipolar devices, e.g. IGBTs and p{sup +}n{sup -}n{sup +} power diodes, that may result in spatial instabilities of the homogeneous current density distribution across the device and the formation of current filaments. Filaments may cause the destruction of the device, mainly because of the high local temperatures. The first part of this work is dedicated to the current filament behavior. The positive feedback mechanisms caused by the transient current flow through the gate capacitance of an IGBT operating under short circuit conditions may result in oscillations and temporal instabilities of the IGBT current. The oscillations may cause electromagnetic interference (EMI). Furthermore, the positive feedback mechanism may accelerate the over-heating of the device and result in a thermal run-away. This is the subject of the second part of this work. In the first part of this work using the device simulation results of power diodes the underlying physical mechanisms of the filament dynamic is investigated. Simulation results of diode structures with evenly distributed doping inhomogeneities show that, the filament motion gets smoother as the distance between the inhomogeneities decreases. Hopping to faraway inhomogeneities turns into the hopping to neighboring ones and finally a smooth motion. In homogeneous structures the slow inhibitory effect of the electron-hole plasma extraction and the fast activation, due to hole current flowing along the filament, result in a smooth filament motion. An analytical model for the filament velocity under isothermal conditions is presented that can reproduce the simulation data satisfactorily. The influence of the boundary conditions on the filament behavior is discussed. The positive beveled edge termination prohibits a long stay of the filament at the edge reducing the risk of filament pinning. Self-heating effects may turn the initially electrically triggered

  8. Customized electric power storage device for inclusion in a collective microgrid

    Science.gov (United States)

    Robinett, III, Rush D.; Wilson, David G.; Goldsmith, Steven Y.

    2016-02-16

    An electric power storage device is described herein, wherein the electric power storage device is included in a microgrid. The electric power storage device has at least one of a charge rate, a discharge rate, or a power retention capacity that has been customized for a collective microgrid. The collective microgrid includes at least two connected microgrids. The at least one of the charge rate, the discharge rate, or the power retention capacity of the electric power storage device is computed based at least in part upon specified power source parameters in the at least two connected microgrids and specified load parameters in the at least two connected microgrids.

  9. UNIPIC code for simulations of high power microwave devices

    International Nuclear Information System (INIS)

    Wang Jianguo; Zhang Dianhui; Wang Yue; Qiao Hailiang; Li Xiaoze; Liu Chunliang; Li Yongdong; Wang Hongguang

    2009-01-01

    In this paper, UNIPIC code, a new member in the family of fully electromagnetic particle-in-cell (PIC) codes for simulations of high power microwave (HPM) generation, is introduced. In the UNIPIC code, the electromagnetic fields are updated using the second-order, finite-difference time-domain (FDTD) method, and the particles are moved using the relativistic Newton-Lorentz force equation. The convolutional perfectly matched layer method is used to truncate the open boundaries of HPM devices. To model curved surfaces and avoid the time step reduction in the conformal-path FDTD method, CP weakly conditional-stable FDTD (WCS FDTD) method which combines the WCS FDTD and CP-FDTD methods, is implemented. UNIPIC is two-and-a-half dimensional, is written in the object-oriented C++ language, and can be run on a variety of platforms including WINDOWS, LINUX, and UNIX. Users can use the graphical user's interface to create the geometric structures of the simulated HPM devices, or input the old structures created before. Numerical experiments on some typical HPM devices by using the UNIPIC code are given. The results are compared to those obtained from some well-known PIC codes, which agree well with each other.

  10. Operation aid device upon periodical inspection of nuclear power plant

    International Nuclear Information System (INIS)

    Fukusaka, Ryoji.

    1997-01-01

    The present invention provides an operation aid device upon periodical inspection of a nuclear power plant, capable of controlling a plurality of control rods safely at good operation efficiency while maintaining subcritical state. Namely, a fuel exchange computer controls an operation for exchanging fuel assemblies upon periodical inspection. An operation aiding computer aids the exchanging operation of fuel assemblies. A control rod position monitoring device allows withdrawal of one control rod under the condition of establishment of entire control rod insertion signal upon operation of exchanging fuel assemblies. Whether all of the four fuel assemblies around one control rod have been entirely taken out or not is judged based on information on the fuel assembly exchanging operation. When conditions for the judgement for operation aiding computer are established, the all insertion signals for the entire control rods as the condition for the withdrawal of the control rods are bypassed, and operation enable signals for plurality control rods are outputted to a control rod manual operation device. (I.S.)

  11. UNIPIC code for simulations of high power microwave devices

    Science.gov (United States)

    Wang, Jianguo; Zhang, Dianhui; Liu, Chunliang; Li, Yongdong; Wang, Yue; Wang, Hongguang; Qiao, Hailiang; Li, Xiaoze

    2009-03-01

    In this paper, UNIPIC code, a new member in the family of fully electromagnetic particle-in-cell (PIC) codes for simulations of high power microwave (HPM) generation, is introduced. In the UNIPIC code, the electromagnetic fields are updated using the second-order, finite-difference time-domain (FDTD) method, and the particles are moved using the relativistic Newton-Lorentz force equation. The convolutional perfectly matched layer method is used to truncate the open boundaries of HPM devices. To model curved surfaces and avoid the time step reduction in the conformal-path FDTD method, CP weakly conditional-stable FDTD (WCS FDTD) method which combines the WCS FDTD and CP-FDTD methods, is implemented. UNIPIC is two-and-a-half dimensional, is written in the object-oriented C++ language, and can be run on a variety of platforms including WINDOWS, LINUX, and UNIX. Users can use the graphical user's interface to create the geometric structures of the simulated HPM devices, or input the old structures created before. Numerical experiments on some typical HPM devices by using the UNIPIC code are given. The results are compared to those obtained from some well-known PIC codes, which agree well with each other.

  12. Observations on Power-Efficiency Trends in Mobile Communication Devices

    Directory of Open Access Journals (Sweden)

    Jyrkkä Kari

    2007-01-01

    Full Text Available Computing solutions used in mobile communications equipment are similar to those in personal and mainframe computers. The key differences between the implementations at chip level are the low leakage silicon technology and lower clock frequency used in mobile devices. The hardware and software architectures, including the operating system principles, are strikingly similar, although the mobile computing systems tend to rely more on hardware accelerators. As the performance expectations of mobile devices are increasing towards the personal computer level and beyond, power efficiency is becoming a major bottleneck. So far, the improvements of the silicon processes in mobile phones have been exploited by software designers to increase functionality and to cut development time, while usage times, and energy efficiency, have been kept at levels that satisfy the customers. Here we explain some of the observed developments and consider means of improving energy efficiency. We show that both processor and software architectures have a big impact on power consumption. Properly targeted research is needed to find the means to explicitly optimize system designs for energy efficiency, rather than maximize the nominal throughputs of the processor cores used.

  13. Observations on Power-Efficiency Trends in Mobile Communication Devices

    Directory of Open Access Journals (Sweden)

    Kari Jyrkkä

    2007-03-01

    Full Text Available Computing solutions used in mobile communications equipment are similar to those in personal and mainframe computers. The key differences between the implementations at chip level are the low leakage silicon technology and lower clock frequency used in mobile devices. The hardware and software architectures, including the operating system principles, are strikingly similar, although the mobile computing systems tend to rely more on hardware accelerators. As the performance expectations of mobile devices are increasing towards the personal computer level and beyond, power efficiency is becoming a major bottleneck. So far, the improvements of the silicon processes in mobile phones have been exploited by software designers to increase functionality and to cut development time, while usage times, and energy efficiency, have been kept at levels that satisfy the customers. Here we explain some of the observed developments and consider means of improving energy efficiency. We show that both processor and software architectures have a big impact on power consumption. Properly targeted research is needed to find the means to explicitly optimize system designs for energy efficiency, rather than maximize the nominal throughputs of the processor cores used.

  14. Silicon carbide devices: more reliability for transmission and distribution systems; Dispositivos de SiC: mais confiabilidade para sistemas de transmissao e distribuicao

    Energy Technology Data Exchange (ETDEWEB)

    Basset, Roger; Ballad, John [Areva T and D Tecnology Centre (United Kingdom)

    2006-05-15

    The silicon carbide power semiconductors will represent an essential role in relation to electrical nets in the future. Counting with higher voltage levels, more rapid commutations and allowing higher temperatures then the current silicon semiconductors, they will result in power electronic equipment with lower dissipation and smaller amount of components, becoming more compacts and reliable.

  15. Accelerated Aging System for Prognostics of Power Semiconductor Devices

    Science.gov (United States)

    Celaya, Jose R.; Vashchenko, Vladislav; Wysocki, Philip; Saha, Sankalita

    2010-01-01

    Prognostics is an engineering discipline that focuses on estimation of the health state of a component and the prediction of its remaining useful life (RUL) before failure. Health state estimation is based on actual conditions and it is fundamental for the prediction of RUL under anticipated future usage. Failure of electronic devices is of great concern as future aircraft will see an increase of electronics to drive and control safety-critical equipment throughout the aircraft. Therefore, development of prognostics solutions for electronics is of key importance. This paper presents an accelerated aging system for gate-controlled power transistors. This system allows for the understanding of the effects of failure mechanisms, and the identification of leading indicators of failure which are essential in the development of physics-based degradation models and RUL prediction. In particular, this system isolates electrical overstress from thermal overstress. Also, this system allows for a precise control of internal temperatures, enabling the exploration of intrinsic failure mechanisms not related to the device packaging. By controlling the temperature within safe operation levels of the device, accelerated aging is induced by electrical overstress only, avoiding the generation of thermal cycles. The temperature is controlled by active thermal-electric units. Several electrical and thermal signals are measured in-situ and recorded for further analysis in the identification of leading indicators of failures. This system, therefore, provides a unique capability in the exploration of different failure mechanisms and the identification of precursors of failure that can be used to provide a health management solution for electronic devices.

  16. The Impact of Power Switching Devices on the Thermal Performance of a 10 MW Wind Power NPC Converter

    DEFF Research Database (Denmark)

    Ma, Ke; Blaabjerg, Frede

    2012-01-01

    Power semiconductor switching devices play an important role in the performance of high power wind energy generation systems. The state-of-the-art device choices in the wind power application as reported in the industry include IGBT modules, IGBT press-pack and IGCT press-pack. Because...

  17. Design of Instantaneous High Power Supply System with power distribution management for portable military devices

    Science.gov (United States)

    Kwak, Kiho; Kwak, Dongmin; Yoon, Joohong

    2015-08-01

    A design of an Instantaneous High Power Supply System (IHPSS) with a power distribution management (PDM) for portable military devices is newly addressed. The system includes a power board and a hybrid battery that can not only supply instantaneous high power but also maintain stable operation at critical low temperature (-30 °C). The power leakage and battery overcharge are effectively prevented by the optimal PDM. The performance of the proposed system under the required pulse loads and the operating conditions of a Korean Advanced Combat Rifle employed in the battlefield is modeled with simulations and verified experimentally. The system with the IHPSS charged the fuse setter with 1.7 times higher voltage (8.6 V) than the one without (5.4 V) under the pulse discharging rate (1 A at 0.5 duty, 1 ms) for 500 ms.

  18. Aging assessment of surge protective devices in nuclear power plants

    International Nuclear Information System (INIS)

    Davis, J.F.; Subudhi, M.; Carroll, D.P.

    1996-01-01

    An assessment was performed to determine the effects of aging on the performance and availability of surge protective devices (SPDs), used in electrical power and control systems in nuclear power plants. Although SPDs have not been classified as safety-related, they are risk-important because they can minimize the initiating event frequencies associated with loss of offsite power and reactor trips. Conversely, their failure due to age might cause some of those initiating events, e.g., through short circuit failure modes, or by allowing deterioration of the safety-related component(s) they are protecting from overvoltages, perhaps preventing a reactor trip, from an open circuit failure mode. From the data evaluated during 1980--1994, it was found that failures of surge arresters and suppressers by short circuits were neither a significant risk nor safety concern, and there were no failures of surge suppressers preventing a reactor trip. Simulations, using the ElectroMagnetic Transients Program (EMTP) were performed to determine the adequacy of high voltage surge arresters

  19. A novel symbiotic organisms search algorithm for optimal power flow of power system with FACTS devices

    Directory of Open Access Journals (Sweden)

    Dharmbir Prasad

    2016-03-01

    Full Text Available In this paper, symbiotic organisms search (SOS algorithm is proposed for the solution of optimal power flow (OPF problem of power system equipped with flexible ac transmission systems (FACTS devices. Inspired by interaction between organisms in ecosystem, SOS algorithm is a recent population based algorithm which does not require any algorithm specific control parameters unlike other algorithms. The performance of the proposed SOS algorithm is tested on the modified IEEE-30 bus and IEEE-57 bus test systems incorporating two types of FACTS devices, namely, thyristor controlled series capacitor and thyristor controlled phase shifter at fixed locations. The OPF problem of the present work is formulated with four different objective functions viz. (a fuel cost minimization, (b transmission active power loss minimization, (c emission reduction and (d minimization of combined economic and environmental cost. The simulation results exhibit the potential of the proposed SOS algorithm and demonstrate its effectiveness for solving the OPF problem of power system incorporating FACTS devices over the other evolutionary optimization techniques that surfaced in the recent state-of-the-art literature.

  20. Monitoring device for the power distribution within a nuclear reactor core

    International Nuclear Information System (INIS)

    Tanzawa, Tomio; Kumanomido, Hironori; Toyoshi, Isamu.

    1986-01-01

    Purpose: To provide a monitoring device for the power distribution in the reactor core that calculates the power distribution based on the measurement by instruments disposed within the reactor core of BWR type reactors. Constitution: The power distribution monitoring device in a reactor core comprises a signal correcting device, a signal normalizing device and a power distribution calculating device, in which the power distribution calculating device is constituted with an average power calculating device for four fuel assemblies and an average power calculating device for fuel assemblies. Gamma-ray signals corrected by the signal correcting device and signals from neutron detectors are inputted to the signal normalizing device, both of which are calibrated to determine the axial gamma-ray signal distribution in the central water gap region with the four fuel assemblies being as the unit. The average power from the four fuel assemblies are inputted to the fuel assembly average power calculating device to allocate to each of the fuel assembly average power thereby attaining the purpose. Further, thermal restriction values are calculated thereby enabling to secure the fuel integrity. (Kamimura, M.)

  1. Cutting device for a local power range monitor tube

    International Nuclear Information System (INIS)

    Watanabe, Shigeru; Tsuji, Teruaki.

    1976-01-01

    Object: To provide a combination of a lifting device for a local power range monitor (LPRM) tube, a cutter and a transfer machine to safely and securely cut the LPRM tube under water. Structure: An LPRM tube is gripped by an LPRM tube gripper, which is moved up and down by a chain drive, through a flexture corrector, and the tip of the LPRM tube is held and released from the LPRM tube gripper so as to be threaded into an LPRM tube cutter to grip it by a transfer gripper of an LPRM tube transfer machine, after which the LPRM tube cutter is operated under pressure water to cut the LPRM tube with a cutter edge so that a cut portion is closed. (Yoshino, Y.)

  2. Autonomy and Housing Accessibility Among Powered Mobility Device Users

    Science.gov (United States)

    Brandt, Åse; Lexell, Eva Månsson; Iwarsson, Susanne

    2015-01-01

    OBJECTIVE. To describe environmental barriers, accessibility problems, and powered mobility device (PMD) users’ autonomy indoors and outdoors; to determine the home environmental barriers that generated the most housing accessibility problems indoors, at entrances, and in the close exterior surroundings; and to examine personal factors and environmental components and their association with indoor and outdoor autonomy. METHOD. This cross-sectional study was based on data collected from a sample of 48 PMD users with a spinal cord injury (SCI) using the Impact of Participation and Autonomy and the Housing Enabler instruments. Descriptive statistics and logistic regression were used. RESULTS. More years living with SCI predicted less restriction in autonomy indoors, whereas more functional limitations and accessibility problems related to entrance doors predicted more restriction in autonomy outdoors. CONCLUSION. To enable optimized PMD use, practitioners must pay attention to the relationship between client autonomy and housing accessibility problems. PMID:26356666

  3. SiC Sensors in Extreme Environments: Real-time Hydrogen Monitoring for Energy Plant Applications

    Science.gov (United States)

    Ghosh, Ruby

    2008-03-01

    Clean, efficient energy production, such as the gasification of coal (syngas), requires physical and chemical sensors for exhaust gas monitoring as well as real-time control of the combustion process. Wide-bandgap semiconducting materials systems can meet the sensing demands in these extreme environments consisting of chemically corrosive gases at high temperature and pressure. We have developed a SiC based micro-sensor for detection of hydrogen containing species with millisecond response at 600 C. The sensor is a Pt-SiO2-SiC device with a dense Pt catalytic sensing film, capable of withstanding months of continuous high temperature operation. The device was characterized in robust sensing module that is compatible with an industrial reactor. We report on the performance of the SiC sensor in a simulated syngas ambient at 370 C containing the common interferants CO2, CH4 and CO [1]. In addition we demonstrate that hours of exposure to >=1000 ppm H2S and 15% water vapor does not degrade the sensor performance. To elucidate the mechanisms responsible for the hydrogen response of the sensor we have modeled the hydrogen adsorptions kinetics at the internal Pt-SiO2 interface, using both the Tempkin and Langmuir isotherms. Under the conditions appropriate for energy plant applications, the response of our sensor is significantly larger than that obtained from ultra-high vacuum electrochemical sensor measurements at high temperatures. We will discuss the role of morphology, at the nano to micro scale, on the enhanced catalytic activity observed for our Pt sensing films in response to a heated hydrogen gas stream at atmospheric pressure. [1] R. Loloee, B. Chorpening, S. Beers & R. Ghosh, Hydrogen monitoring for power plant applications using SiC sensors, Sens. Actuators B:Chem. (2007), doi:10.1016/j.snb.2007.07.118

  4. Design and comparison of a 10-kW interleaved boost converter for PV application using Si and SiC devices

    NARCIS (Netherlands)

    Chandra Mouli, G.R.; Schijffelen, Jos H.; Bauer, P.; Zeman, M.

    2017-01-01

    Grid-connected photovoltaic (PV) inverters have a dc/dc converter connected to the PV for executing the maximum power point tracking. The design of an interleaved boost converter (IBC) with three switching legs for a 10-kW PV inverter is presented in this paper. This paper shows how the use of

  5. Power loss measurement of implantable wireless power transfer components using a Peltier device balance calorimeter

    International Nuclear Information System (INIS)

    Leung, Ho Yan; Budgett, David M; Taberner, Andrew; Hu, Patrick

    2014-01-01

    Determining heat losses in power transfer components operating at high frequencies for implantable inductive power transfer systems is important for assessing whether the heat dissipated by the component is acceptable for implantation and medical use. However, this is a challenge at high frequencies and voltages due to limitations in electronic instrumentation. Calorimetric methods of power measurement are immune to the effects of high frequencies and voltages; hence, the measurement is independent of the electrical characteristics of the system. Calorimeters have been widely used to measure the losses of high power electrical components (>50 W), however it is more difficult to perform on low power components. This paper presents a novel power measurement method for components dissipating anywhere between 0.2 W and 1 W of power based on a heat balance calorimeter that uses a Peltier device as a balance sensor. The proposed balance calorimeter has a single test accuracy of ±0.042 W. The experimental results revealed that there was up to 35% difference between the power measurements obtained with electrical methods and the proposed calorimeter. (paper)

  6. Simulation study of a high power density rectenna array for biomedical implantable devices

    Science.gov (United States)

    Day, John; Yoon, Hargsoon; Kim, Jaehwan; Choi, Sang H.; Song, Kyo D.

    2016-04-01

    The integration of wireless power transmission devices using microwaves into the biomedical field is close to a practical reality. Implanted biomedical devices need a long lasting power source or continuous power supply. Recent development of high efficiency rectenna technology enables continuous power supply to these implanted devices. Due to the size limit of most of medical devices, it is imperative to minimize the rectenna as well. The research reported in this paper reviews the effects of close packing the rectenna elements which show the potential of directly empowering the implanted devices, especially within a confined area. The rectenna array is tested in the X band frequency range.

  7. Complete Loss and Thermal Model of Power Semiconductors Including Device Rating Information

    DEFF Research Database (Denmark)

    Ma, Ke; Bahman, Amir Sajjad; Beczkowski, Szymon

    2015-01-01

    Thermal loading of power devices are closely related to the reliability performance of the whole converter system. The electrical loading and device rating are both important factors that determine the loss and thermal behaviors of power semiconductor devices. In the existing loss and thermal...

  8. 78 FR 33849 - Battery-Powered Medical Devices Workshop: Challenges and Opportunities; Public Workshop; Request...

    Science.gov (United States)

    2013-06-05

    ... after the public workshop on the Internet at http://www.fda.gov/MedicalDevices/NewsEvents/Workshops..., compact, and mobile, the number of battery-powered medical devices will continue to increase. While many...] Battery-Powered Medical Devices Workshop: Challenges and Opportunities; Public Workshop; Request for...

  9. Organic material reducing device in nuclear power plant

    International Nuclear Information System (INIS)

    Minakata, Noriyuki; Takada, Takao

    1998-01-01

    A total organic carbon (TOC) removing device is disposed between a filtration device and a desalting device or between a condensator and the desalting device disposed to a radioactive liquid waste processing facility or a condensate cleaning system of a BWR type nuclear reactor. Since the removing ratio of the TOC removing device is generally high if impurities are not contained, and ionic ingredients are formed after decomposition, TOC can be decomposed and removed more efficiently and removal in a short period of time can be expected by disposing the TOC device downstream of the filtration device or a condensator to be disposed instead of the filtration device and upstream of the desalting device. Then, further enhanced effect can be expected, if two series of the TOC removing line and the bypass line are disposed between the filtration device or the condensator and the desalting device so as to enable selection of processed liquids. (T.M.)

  10. Magnetic field generation device for magnetohydrodynamic electric power generation

    International Nuclear Information System (INIS)

    Kuriyama, Yoshihiko.

    1993-01-01

    An existent magnetic field generation device for magnetohydrodynamic electric power generation comprises at least a pair of permanent magnets disposed to an inner circumferential surface of a yoke having such a cross sectional area that two pairs of parallel sides are present, in which different magnetic poles are opposed while interposing a flow channel for a conductive fluid therebetween. Then, first permanent magnets which generate main magnetic fields are disposed each at a gap sandwiching a plane surface including a center axis of a flow channel for the conductive fluid. Second permanent magnets which generate auxiliary magnetic fields are disposed to an inner circumferential surface of a yoke intersecting the yoke to which the first permanent magnets are disposed. The magnetic poles on the side of the flow channel for the second permanent magnets have identical polarity with that of the magnetic poles of the adjacent first permanent magnets. As a result, a magnetic flux density in the flow channel for the conductive fluid can be kept homogeneous and at a high level from a position of the axial line of the flow channel to the outer circumference, thereby enabling to remarkably improve a power generation efficiency. (N.H.)

  11. Cutting device for spent local power range monitor

    International Nuclear Information System (INIS)

    Watanabe, Shigeru; Tsuji, Teruaki.

    1976-01-01

    Purpose: To prevent radioactive contamination of the reactor water and simplify the operation of transferring the spent local power range monitor to a pool and preparation of the space for storing the monitor in the pool by arranging it such that the monitor is cut in the reactor water and that its cut end is closed in the reactor water. Constitution: A device for clamping a spent local power range monitor disposed within the reactor core and for cutting the monitor such that the content will not be exposed are supported by support means such that they are spaced apart in the vertical direction, and the support means is suspended in the reactor water such that it is movable relative to the monitor. Thus, there is no need to mount the cutter in any separately provided support means, and there is no possibility of exposure of the content since the cut end of the monitor is closed by the outer frame. It is therefore possible to prevent contamination of the reactor water. (Horiuchi, T.)

  12. Self-operation type power control device for nuclear reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kanbe, Mitsuru.

    1993-07-23

    The device of the present invention operates by sensing the temperature change of a reactor core in all of LMFBR type reactors irrespective of the scale of the reactor core power. That is, a region where liquid poison is filled is disposed at the upper portion and a region where sealed gases are filled is disposed at the lower portion of a pipe having both ends thereof being closed. When the pipe is inserted into the reactor core, the inner diameter of the pipe is determined smaller than a predetermined value so that the boundary between the liquid poison and the sealed gases in the pipe is maintained relative to an assumed maximum acceleration. The sealed gas region is disposed at the reactor core region. If the liquid poison is expanded by the elevation of the reactor core exit temperature, it is moved to the lower gas region, to control the reactor power. Since high reliability can be maintained over a long period of time by this method, it is suitable to FBR reactors disposed in such environments that maintenance can not easily be conducted, such as desserts, isolated islands and undeveloped countries. Further, it is also suitable to ultra small sized nuclear reactors disposed at environments that the direction and the magnitude of gravity are different from those on the ground. (I.S.).

  13. Self-operation type power control device for nuclear reactor

    International Nuclear Information System (INIS)

    Kanbe, Mitsuru.

    1993-01-01

    The device of the present invention operates by sensing the temperature change of a reactor core in all of LMFBR type reactors irrespective of the scale of the reactor core power. That is, a region where liquid poison is filled is disposed at the upper portion and a region where sealed gases are filled is disposed at the lower portion of a pipe having both ends thereof being closed. When the pipe is inserted into the reactor core, the inner diameter of the pipe is determined smaller than a predetermined value so that the boundary between the liquid poison and the sealed gases in the pipe is maintained relative to an assumed maximum acceleration. The sealed gas region is disposed at the reactor core region. If the liquid poison is expanded by the elevation of the reactor core exit temperature, it is moved to the lower gas region, to control the reactor power. Since high reliability can be maintained over a long period of time by this method, it is suitable to FBR reactors disposed in such environments that maintenance can not easily be conducted, such as desserts, isolated islands and undeveloped countries. Further, it is also suitable to ultra small sized nuclear reactors disposed at environments that the direction and the magnitude of gravity are different from those on the ground. (I.S.)

  14. Isolation valve control device for nuclear power plant

    International Nuclear Information System (INIS)

    Yukinori, Shigeru.

    1990-01-01

    The present invention provides an isolation valve control device for detecting pipeline rupture accidents in a BWR type nuclear power plant at an early stage to close an isolation valve thereby reducing the amout of radioactivity released to the circumstance. That is, isolation valves are disposed in the pipeline for each of the systems in the nuclear power plant and flow ratemeters are disposed to at least two positions in each of the pipelines. If a meaningful difference is shown for the measured values by these flow ratemeters, the isolation valve is closed. In this way, if pipeline rupture such as leak before break (LBB) is caused to a portion of a system pipelines, the measured value from the flow ratemeters at the downstream of the pipeline is lowered. Accordingly, when a meaningful difference is formed between the value of the flow ratematers at the upstream and the downstream, occurrence of pipe rutpture between both of the flow ratemeters can be detected. As a result, the isolation valves of the system can be closed. According to the present invention, it is possible to detect the pipeline rupture at an early stage irrespective of the kind of the systems, diameter of the pipelines and the magnitude of the ruptured area, and the isolation valve can be closed. (I.S.)

  15. Alkali (Li, K and Na) and alkali-earth (Be, Ca and Mg) adatoms on SiC single layer

    Science.gov (United States)

    Baierle, Rogério J.; Rupp, Caroline J.; Anversa, Jonas

    2018-03-01

    First-principles calculations within the density functional theory (DFT) have been addressed to study the energetic stability, and electronic properties of alkali and alkali-earth atoms adsorbed on a silicon carbide (SiC) single layer. We observe that all atoms are most stable (higher binding energy) on the top of a Si atom, which moves out of the plane (in the opposite direction to the adsorbed atom). Alkali atoms adsorbed give raise to two spin unpaired electronic levels inside the band gap leading the SiC single layer to exhibit n-type semiconductor properties. For alkaline atoms adsorbed there is a deep occupied spin paired electronic level inside the band gap. These finding suggest that the adsorption of alkaline and alkali-earth atoms on SiC layer is a powerful feature to functionalize two dimensional SiC structures, which can be used to produce new electronic, magnetic and optical devices as well for hydrogen and oxygen evolution reaction (HER and OER, respectively). Furthermore, we observe that the adsorption of H2 is ruled by dispersive forces (van der Waals interactions) while the O2 molecule is strongly adsorbed on the functionalized system.

  16. Microwave joining of SiC ceramics and composites

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, I.; Silberglitt, R.; Tian, Y.L. [FM Technologies, Inc., Fairfax, VA (United States); Katz, J.D. [Los Alamos National Lab., NM (United States)

    1997-04-01

    Potential applications of SiC include components for advanced turbine engines, tube assemblies for radiant burners and petrochemical processing and heat exchangers for high efficiency electric power generation systems. Reliable methods for joining SiC are required in order to cost-effectively fabricate components for these applications from commercially available shapes and sizes. This manuscript reports the results of microwave joining experiments performed using two different types of SiC materials. The first were on reaction bonded SiC, and produced joints with fracture toughness equal to or greater than that of the base material over an extended range of joining temperatures. The second were on continuous fiber-reinforced SiC/SiC composite materials, which were successfully joined with a commercial active brazing alloy, as well as by using a polymer precursor.

  17. An Extension of SIC Predictions to the Wiener Coactive Model.

    Science.gov (United States)

    Houpt, Joseph W; Townsend, James T

    2011-06-01

    The survivor interaction contrasts (SIC) is a powerful measure for distinguishing among candidate models of human information processing. One class of models to which SIC analysis can apply are the coactive, or channel summation, models of human information processing. In general, parametric forms of coactive models assume that responses are made based on the first passage time across a fixed threshold of a sum of stochastic processes. Previous work has shown that that the SIC for a coactive model based on the sum of Poisson processes has a distinctive down-up-down form, with an early negative region that is smaller than the later positive region. In this note, we demonstrate that a coactive process based on the sum of two Wiener processes has the same SIC form.

  18. Characterization and Aging Test Methodology for Power Electronic Devices at High Temperature

    International Nuclear Information System (INIS)

    Ibrahim, A.; Khatir, Z.; Dupont, L.

    2011-01-01

    Power electronic modules are key elements in the chain of power conversion. The application areas include aerospace, aviation, railway, electrical distribution, automotive, home automation, oil industry ... But the use of power electronics in high temperature environments is a major strategic issue in the coming years especially in transport. However, the active components based on silicon are limited in their applications and not suitable for those require both high voltages and high ambient temperatures. The materials with wide energy gap like SiC, GaN and diamond, have the advantage of being able to exceed these limits [1,2]. These materials seem adequate to extremely harsh temperature environments and allow the reduction of cooling systems, but also the increasing of switching frequency. (author)

  19. Performance Evaluation of an Automotive-Grade, High Speed Gate Driver for SiC FETs, Type UCC27531, Over a Wide Temperature Range

    Science.gov (United States)

    Boomer, Kristen; Hammoud, Ahmad

    2015-01-01

    Silicon carbide (SiC) devices are becoming widely used in electronic power circuits as replacement for conventional silicon parts due to their attractive properties that include low on-state resistance, high temperature tolerance, and high frequency operation. These attributes have a significant impact by reducing system weight, saving board space, and conserving power. In this work, the performance of an automotive-grade high speed gate driver with potential use in controlling SiC FETs (field-Effect Transistors) in converters or motor control applications was evaluated under extreme temperatures and thermal cycling. The investigations were carried out to assess performance and to determine suitability of this device for use in space exploration missions under extreme temperature conditions.

  20. Gaseous waste processing device in nuclear power plant

    International Nuclear Information System (INIS)

    Takechi, Eisuke; Matsutoshi, Makoto.

    1978-01-01

    Purpose: To arrange the units of waste processing devices in a number one more than the number thereof required for a plurality of reactors, and to make it usable commonly as a preliminary waste processing device thereby to effectively use all the gaseous waste processing devices. Constitution: A gaseous waste processing device is constituted by an exhaust gas extractor, a first processing device, a second processing device and the like, which are all connected in series. Upon this occasion, devices from the exhaust gas extractor to the first processing device and valves, which are provided in each of reactors, are arranged in series, on one hand, but valves at the downstream side join one another by one pipeline, and are connected to a stack through a total gaseous waste processing device, on another. (Yoshihara, H.)

  1. Impacts of Ripple Current to the Loading and Lifetime of Power Semiconductor Device

    DEFF Research Database (Denmark)

    Ma, Ke; Choi, Uimin; Blaabjerg, Frede

    2017-01-01

    The thermal loading of power electronics devices is determined by many factors and has being a crucial design consideration because it is closely related to the reliability and cost of the converter system. In this paper the impacts of the ripple current to the loss and thermal loading, as well...... as reliability performances of power devices are comprehensively investigated and tested. It is concluded that the amplitude of ripple current may modify the loss and thermal loading of the power devices, especially under the conditions of converter with low power output, and thus the lifetime of devices could...

  2. Hydrogen transfer preventive device in FBR power plant

    International Nuclear Information System (INIS)

    Hoshi, Yuichi.

    1987-01-01

    Purpose: To prevent transfer of hydrogen, etc. in FBR power plant. Constitution: Since H 2 permeates heat conduction pipes in a steam generator, it is necessary to eliminate all of permeation hydrogen, etc. by primary cold traps particularly in the case of saving the intermediate heat exchange. In view of the above, the heat conduction pipes of the steam generator are constituted as a double pipe structure and helium gases are recycled through the gaps thereof and hydrogen traps are disposed to the recycling path. H 2 released into water flowing through the inside of the inner pipe is permeated through the inner pipe and leached into the gap, but the leached H 2 is carried by the helium recycling stream to the hydrogen trap and then the H 2 stream removed with H 2 is returned to the gaps. In this way, the capacity of the primary cold traps disposed in the liquid sodium recycling circuit can be reduced remarkably and the capacity of the purifying device, if an intermediate heat exchanger is disposed, is also reduced to decrease the plant cost. Further, diffusion of deleterious gases from the primary to the secondary circuits can be prevented as well. (Kamimura, M.)

  3. Nitrogen gas supply device in nuclear power plant

    International Nuclear Information System (INIS)

    Nishino, Masami

    1991-01-01

    The present invention concerns a nitrogen gas supply device in a nuclear power plant for supplying nitrogen gases to a reactor container and equipments working with the nitrogen gas as the load. A liquid nitrogen storage pool is disposed to a concrete nuclear buildings and has a two-vessel structure of inner and outer vessels, in which heat insulators are disposed between the inner and the outer vessels. Further, the nitrogen gas supply mechanism is disposed in an evaporation chamber disposed in adjacent with the liquid nitrogen storage pool in the reator building. Accordingly, since liquid nitrogen is stored in the liquid nitrogen storage pool having a structure surrounded by concrete walls, direct sunlight is completely interrupted, thereby enabling to prevent the heat caused by the direct sunlight from conducting to the liquid nitrogen. Further, since the outer vessel is not exposed to the surrounding atmosphere, heat conduction rate relative to the external air is small. This can reduce the amount of liquid nitrogen released to the atmospheric air due to natural evaporation. (I.N.)

  4. BIPV-powered smart windows utilizing photovoltaic and electrochromic devices.

    Science.gov (United States)

    Ma, Rong-Hua; Chen, Yu-Chia

    2012-01-01

    A BIPV-powered smart window comprising a building-integrated photovoltaic (BIPV) panel and an all-solid-state electrochromic (EC) stack is proposed. In the proposed device, the output voltage of the BIPV panel varies in accordance with the intensity of the incident light and is modulated in such a way as to generate the EC stack voltage required to maintain the indoor illuminance within a specified range. Two different EC stacks are fabricated and characterized, namely one stack comprising ITO/WO(3)/Ta(2)O(5)/ITO and one stack comprising ITO/WO(3)/lithium-polymer electrolyte/ITO. It is shown that of the two stacks, the ITO/WO(3)/lithium-polymer electrolyte/ITO stack has a larger absorptance (i.e., approximately 99% at a driving voltage of 3.5 V). The experimental results show that the smart window incorporating an ITO/WO(3)/lithium-polymer electrolyte/ITO stack with an electrolyte thickness of 1.0 μm provides an indoor illuminance range of 750-1,500 Lux under typical summertime conditions in Taiwan.

  5. BIPV-Powered Smart Windows Utilizing Photovoltaic and Electrochromic Devices

    Directory of Open Access Journals (Sweden)

    Yu-Chia Chen

    2011-12-01

    Full Text Available A BIPV-powered smart window comprising a building-integrated photovoltaic (BIPV panel and an all-solid-state electrochromic (EC stack is proposed. In the proposed device, the output voltage of the BIPV panel varies in accordance with the intensity of the incident light and is modulated in such a way as to generate the EC stack voltage required to maintain the indoor illuminance within a specified range. Two different EC stacks are fabricated and characterized, namely one stack comprising ITO/WO3/Ta2O5/ITO and one stack comprising ITO/WO3/lithium-polymer electrolyte/ITO. It is shown that of the two stacks, the ITO/WO3/lithium-polymer electrolyte/ITO stack has a larger absorptance (i.e., approximately 99% at a driving voltage of 3.5 V. The experimental results show that the smart window incorporating an ITO/WO3/lithium-polymer electrolyte/ITO stack with an electrolyte thickness of 1.0 μm provides an indoor illuminance range of 750–1,500 Lux under typical summertime conditions in Taiwan.

  6. Reactor core cooling device for nuclear power plant

    International Nuclear Information System (INIS)

    Tsuda, Masahiko.

    1992-01-01

    The present invention concerns a reactor core cooling facility upon rupture of pipelines in a BWR type nuclear power plant. That is, when rupture of pipelines should occur in the reactor container, an releasing safety valve operates instantly and then a depressurization valve operates to depressurize the inside of a reactor pressure vessel. Further, an injection valve of cooling water injection pipelines is opened and cooling water is injected to cool the reactor core from the time when the pressure is lowered to a level capable of injecting water to the pressure vessel by the static water head of a pool water as a water source. Further, steams released from the pressure vessel and steams in the pressure vessel are condensed in a high pressure/low pressure emergency condensation device and the inside of the reactor container is depressurized and cooled. When the reactor is isolated, since the steams in the pressure vessel are condensed in the state that the steam supply valve and the return valve of a steam supply pipelines are opened and a vent valve is closed, the reactor can be maintained safely. (I.S.)

  7. Device for forecasting reactor power-up routes

    International Nuclear Information System (INIS)

    Fukuzaki, Takaharu.

    1980-01-01

    Purpose: To improve the reliability and forecasting accuracy for a device forecasting the change of the state on line in BWR type reactors. Constitution: The present state in a nuclear reactor is estimated in a present state judging section based on measuring signals for thermal power, core flow rate, control rod density and the like from the nuclear reactor, and the estimated results are accumulated in an operation result collecting section. While on the other hand, a forecasting section forecasts the future state in the reactor based on the signals from the forecasting condition setting section. The actual result values from the collecting section and the forecasting results are compared to each other. If they are not equal, new setting signals are outputted from the setting section to perform the forecasting again. These procedures are repeated till the difference between the forecast results and the actual result values is minimized, by which accurate forecasting for the state of the reactor is made possible. (Furukawa, Y.)

  8. Influences of Device and Circuit Mismatches on Paralleling Silicon Carbide MOSFETs

    DEFF Research Database (Denmark)

    Li, Helong; Munk-Nielsen, Stig; Wang, Xiongfei

    2016-01-01

    This paper addresses the influences of device and circuit mismatches on paralleling the Silicon Carbide (SiC) MOSFETs. Comprehensive theoretical analysis and experimental validation from paralleled discrete devices to paralleled dies in multichip power modules are first presented. Then, the influ......This paper addresses the influences of device and circuit mismatches on paralleling the Silicon Carbide (SiC) MOSFETs. Comprehensive theoretical analysis and experimental validation from paralleled discrete devices to paralleled dies in multichip power modules are first presented. Then......, the influence of circuit mismatch on paralleling SiC MOSFETs is investigated and experimentally evaluated for the first time. It is found that the mismatch of the switching loop stray inductance can also lead to on-state current unbalance with inductive output current, in addition to the on-state resistance...... of the device. It further reveals that circuit mismatches and a current coupling among the paralleled dies exist in a SiC MOSFET multichip power module, which is critical for the transient current distribution in the power module. Thus, a power module layout with an auxiliary source connection is developed...

  9. Impact of Thyristors Controlled Series Capacitor Devices and Optimal Power Flow on Power Systems

    Directory of Open Access Journals (Sweden)

    Fatiha LAKDJA

    2010-12-01

    Full Text Available This paper presents an algorithm, for solving the Optimal Power Flow problem with flexible AC transmission systems (FACTS. The type of FACTS devices is used: thyristor-controlled series capacitor (TCSC. A method to determine the optimal location of thyristor controlled series compensators has been suggested. The proposed approaches have been implemented on an adapted IEEE 26 bus system. The simulation results are discussed to show the performance of the proposed algorithm and our “FACTS programmer “simulator technique, which are compared with TCSC and without TCSC.

  10. High Efficiency Reversible Fuel Cell Power Converter

    DEFF Research Database (Denmark)

    Pittini, Riccardo

    as well as different dc-ac and dc-dc converter topologies are presented and analyzed. A new ac-dc topology for high efficiency data center applications is proposed and an efficiency characterization based on the fuel cell stack I-V characteristic curve is presented. The second part discusses the main...... converter components. Wide bandgap power semiconductors are introduced due to their superior performance in comparison to traditional silicon power devices. The analysis presents a study based on switching loss measurements performed on Si IGBTs, SiC JFETs, SiC MOSFETs and their respective gate drivers...

  11. Quantitative analyses of impurity silicon-carbide (SiC) and high-purity-titanium by neutron activation analyses based on k0-standardization method. Development of irradiation silicon technology in productivity using research reactor (Joint research)

    International Nuclear Information System (INIS)

    Motohashi, Jun; Takahashi, Hiroyuki; Magome, Hirokatsu; Sasajima, Fumio; Tokunaga, Okihiro; Kawasaki, Kozo; Onizawa, Koji; Isshiki, Masahiko

    2009-07-01

    JRR-3 and JRR-4 have been providing neutron-transmutation-doped silicon (NTD-Si) by using the silicon NTD process, which is a method to produce a high quality semiconductor. The domestic supply of NTD-Si is insufficient for the demand, and the market of NTD-Si is significantly growing at present. It is very important to increase achieve the production. To fulfill the requirement, we have been investigating a neutron filter, which is made of high-purity-titanium, for uniform doping. Silicon-carbide (SiC) semiconductor doped with NTD technology is considered suitable for high power devices with superior performances to conventional Si-based devices. We are very interested in the SiC as well. This report presents the results obtained after the impurity contents in the high-purity-titanium and SiC were analyzed by neutron activation analyses (NAA) using k 0 -standardization method. There were 6 and 9 impurity elements detected from the high-purity-titanium and SiC, respectively. Among those Sc from the high-purity-titanium and Fe from SiC were comparatively long half life nuclides. From the viewpoint of exposure in handling them, we need to examine the impurity control of materials. (author)

  12. Triple tooth AlGaN/GaN HEMT on SiC substrate: A novel structure for high-power applications

    Science.gov (United States)

    Ghaffari, Majid; Orouji, Ali A.; Valinataj, Mojtaba

    2017-12-01

    In this paper, a AlGaN/AlN/GaN/SiC High Electron Mobility Transistor (HEMT) to reduce the electric field is suggested. The main idea of this work is to improve the Direct Current (DC) and Radio Frequency (RF) properties of device by modifying the depletion region in the channel. The proposed structure consists of a floating metal like a comb with triple tooth which is located in the space between the gate and drain and inside the buffer layer. We called the proposed structure as triple tooth HEMT (TT-HEMT). The RF and DC characteristics of the proposed structure are studied using numerical simulations. The breakdown voltage ( V BR ) increases to 169.5 V for the proposed structure in comparison with 103 V for the conventional HEMT (C-HEMT) due to the modified electric field distribution in the channel of the TT-HEMT structure. The maximum output power density ( P max ) of the TT-HEMT structure is 60.4% greater than that of the C-HEMT. The optimized results show that the maximum oscillation frequency ( f max ) and cut-off frequency (fT) of the proposed structure improve 111% and 26.5%, respectively compared to the C-HEMT structure. In addition, the maximum available gain (MAG) of the TT-HEMT structure is obtained 8.5 dB higher than that of the C-HEMT structure at the frequency of 40 GHz. The optimal results show that whatever the number of teeth on metal increases, the depletion region in the channel is modified more and the breakdown voltage increases, as well. Besides, the output power density ( P max ) is improved with the increasing number of teeth on metal (N). This characteristic is also true, for the cut-off frequency ( f T ), the maximum oscillation frequency ( f max ) and the maximum available gain (MAG) of the proposed structure. However, the drain current ( I D ) of the proposed structure is reduced.

  13. Load power device, system and method of load control and management employing load identification

    Science.gov (United States)

    Yang, Yi; Luebke, Charles John; Schoepf, Thomas J.

    2018-01-09

    A load power device includes a power input, at least one power output for at least one load, a plurality of sensors structured to sense voltage and current at the at least one power output, and a processor. The processor provides: (a) load identification based upon the sensed voltage and current, and (b) load control and management based upon the load identification.

  14. Comparative study of leakage power in CNTFET over MOSFET device

    International Nuclear Information System (INIS)

    Sinha Sanjeet Kumar; Chaudhury Saurabh

    2014-01-01

    A comparison of the CNTFET device with the MOSFET device in the nanometer regime is reported. The characteristics of both devices are observed as varying the oxide thickness. Thereafter, we have analyzed the effect of the chiral vector and the temperature on the threshold voltage of the CNTFET device. After simulation on the HSPICE tool, we observed that the high threshold voltage can be achieved at a low chiral vector pair. It is also observed that the effect of temperature on the threshold voltage of the CNTFET is negligibly small. After that, we have analyzed the channel length variation and their impact on the threshold voltage of the CNTFET as well as MOSFET devices. We found an anomalous effect from our simulation result that the threshold voltage increases with decreasing the channel length in CNTFET devices; this is contrary to the well known short channel effect. It is observed that at below the 10 nm channel length, the threshold voltage is increased rapidly in the case of the CNTFET device, whereas in the case of the MOSFET device, the threshold voltage decreases drastically. (semiconductor devices)

  15. Bi-directional magnetic resonance based wireless power transfer for electronic devices

    International Nuclear Information System (INIS)

    Kar, Durga P.; Nayak, Praveen P.; Bhuyan, Satyanarayan; Mishra, Debasish

    2015-01-01

    In order to power or charge electronic devices wirelessly, a bi-directional wireless power transfer method has been proposed and experimentally investigated. In the proposed design, two receiving coils are used on both sides of a transmitting coil along its central axis to receive the power wirelessly from the generated magnetic fields through strongly coupled magnetic resonance. It has been observed experimentally that the maximum power transfer occurs at the operating resonant frequency for optimum electric load connected across the receiving coils on both side. The optimum wireless power transfer efficiency is 88% for the bi-directional power transfer technique compared 84% in the one side receiver system. By adopting the developed bi-directional power transfer method, two electronic devices can be powered up or charged simultaneously instead of a single device through usual one side receiver system without affecting the optimum power transfer efficiency

  16. Bi-directional magnetic resonance based wireless power transfer for electronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Kar, Durga P.; Nayak, Praveen P.; Bhuyan, Satyanarayan; Mishra, Debasish [Department of Electronics and Instrumentation Engineering, Institute of Technical Education and Research, Siksha ‘O’ Anushandhan University, Bhubaneswar 751030 (India)

    2015-09-28

    In order to power or charge electronic devices wirelessly, a bi-directional wireless power transfer method has been proposed and experimentally investigated. In the proposed design, two receiving coils are used on both sides of a transmitting coil along its central axis to receive the power wirelessly from the generated magnetic fields through strongly coupled magnetic resonance. It has been observed experimentally that the maximum power transfer occurs at the operating resonant frequency for optimum electric load connected across the receiving coils on both side. The optimum wireless power transfer efficiency is 88% for the bi-directional power transfer technique compared 84% in the one side receiver system. By adopting the developed bi-directional power transfer method, two electronic devices can be powered up or charged simultaneously instead of a single device through usual one side receiver system without affecting the optimum power transfer efficiency.

  17. Loss and thermal model for power semiconductors including device rating information

    DEFF Research Database (Denmark)

    Ma, Ke; Bahman, Amir Sajjad; Beczkowski, Szymon

    2014-01-01

    The electrical loading and device rating are both important factors that determine the loss and thermal behaviors of power semiconductor devices. In the existing loss and thermal models, only the electrical loadings are focused and treated as design variables, while the device rating is normally...

  18. Single-event burnout of power MOSFET devices for satellite application

    International Nuclear Information System (INIS)

    Xue Yuxiong; Tian Kai; Cao Zhou; Yang Shiyu; Liu Gang; Cai Xiaowu; Lu Jiang

    2008-01-01

    Single-event burnout (SEB) sensitivity was tested for power MOSFET devices, JTMCS081 and JTMCS062, which were made in Institute of Microelectronics, Chinese Academy of Sciences, using californium-252 simulation source. SEB voltage threshold was found for devices under test (DUT). It is helpful for engineers to choose devices used in satellites. (authors)

  19. Assessment of intrinsic small signal parameters of submicron SiC MESFETs

    Science.gov (United States)

    Riaz, Mohammad; Ahmed, Muhammad Mansoor; Rafique, Umair; Ahmed, Umer Farooq

    2018-01-01

    In this paper, a technique has been developed to estimate intrinsic small signal parameters of submicron SiC MESFETs, designed for high power microwave applications. In the developed technique, small signal parameters are extracted by involving drain-to-source current, Ids instead of Schottky barrier depletion layer expression. It has been demonstrated that in SiC MESFETs, the depletion layer gets modified due to intense transverse electric field and/or self-heating effects, which are conventionally not taken into account. Thus, assessment of AC small signal parameters by employing depletion layer expression loses its accuracy for devices meant for high power applications. A set of expressions for AC small signal elements has been developed using Ids and its dependence on device biasing has been discussed. The validity of the proposed technique has been demonstrated using experimental data. Dr. Ahmed research interests are in Microelectronics, Microwave and RF Engineering and he has supervised numerous MS and PhD research projects. He authored over 100 research papers in the field of microelectronics. Dr. Ahmed is a fellow of the Institution of Engineering and Technology (IET), UK.; a Chartered Engineer (CEng) from the UK Engineering Council and holds the title of European Engineer (Eur Ing) from the European Federation of National Engineering Association (FEANI), Brussels. He is a life member of PEC (Pak); EDS & MTTS (USA).

  20. 77 FR 32642 - Medical Devices; Exemption From Premarket Notification: Powered Patient Transport

    Science.gov (United States)

    2012-06-01

    ...] Medical Devices; Exemption From Premarket Notification: Powered Patient Transport AGENCY: Food and Drug... received a petition requesting exemption from the premarket notification requirements for powered patient... necessary to provide a reasonable assurance of safety and effectiveness. Under the Medical Device Amendments...

  1. Integrated Silicon Carbide Power Electronic Block

    Energy Technology Data Exchange (ETDEWEB)

    Radhakrishnan, Rahul [Global Power Technologies Group, Inc., Lake Forest, CA (United States)

    2017-11-07

    Research involved in this project is aimed at monolithically integrating an anti-parallel diode to the SiC MOSFET switch, so as to avoid having to use an external anti-parallel diode in power circuit applications. SiC MOSFETs are replacing Si MOSFETs and IGBTs in many applications, yet the high bandgap of the body diode in SiC MOSFET and consequent need for an external anti-parallel diode increases costs and discourages circuit designers from adopting this technology. Successful demonstration and subsequent commercialization of this technology would reduce SiC MOSFET cost and additionally reduce component count as well as other costs at the power circuit level. In this Phase I project, we have created multiple device designs, set up a process for device fabrication at the 150mm SiC foundry XFAB Texas, demonstrated unit-processes for device fabrication in short loops and started full flow device fabrication. Key findings of the development activity were: The limits of coverage of photoresist over the topology of thick polysilicon structures covered with oxide, which required larger feature dimensions to overcome; and The insufficient process margin for removing oxide spacers from polysilicon field ring features which could result in loss of some features without further process development No fundamental obstacles were uncovered during the process development. Given sufficient time for additional development it is likely that processes could be tuned to realize the monolithically integrated SiC JBS diode and MOSFET. Sufficient funds were not available in this program to resolve processing difficulties and fabricate the devices.

  2. Low Power Design for Future Wearable and Implantable Devices

    DEFF Research Database (Denmark)

    Lundager, Katrine; Zeinali, Behzad; Tohidi, Mohammad

    2016-01-01

    limit, which is a critical limit for further miniaturization to develop smaller and smarter wearable/implantable devices (WIDs), especially for multi-task continuous computing purposes. Developing smaller and smarter devices with more functionality requires larger batteries, which are currently the main...

  3. Wearable thermoelectric generators for body-powered devices

    NARCIS (Netherlands)

    Leonov, V.; Vullers, R.J.M.

    2009-01-01

    This paper presents a discussion on energy scavenging for wearable devices in conjunction with human body properties. Motivation, analysis of the relevant properties of the human body, and results of optimization of a thermopile and a thermoelectric generator for wearable and portable devices are

  4. Measuring the power consumption of social media applications on a mobile device

    Science.gov (United States)

    Dunia, A. I. M.; Suherman; Rambe, A. H.; Fauzi, R.

    2018-03-01

    As fully connected social media applications become popular and require all time connection, the power consumption on mobile device battery increases significantly. As power supplied by a battery is limited, social media application should be designed to be less power consuming. This paper reports the power consumption measurement of social media running on a mobile device. Experimental circuit was developed by using a microcontroller measuring an android smartphone on a 802.11 controlled network. The experiment results show that whatsapp consumes the power less than others in stand by and chat. While other states are dominated by line. The blackberry consumes the power the worst.

  5. A CMOS self-powered front-end architecture for subcutaneous event-detector devices

    CERN Document Server

    Colomer-Farrarons, Jordi

    2011-01-01

    A CMOS Self-Powered Front-End Architecture for Subcutaneous Event-Detector Devices presents the conception and prototype realization of a Self-Powered architecture for subcutaneous detector devices. The architecture is designed to work as a true/false (event detector) or threshold level alarm of some substances, ions, etc. that are detected through a three-electrodes amperometric BioSensor approach. The device is conceived as a Low-Power subcutaneous implantable application powered by an inductive link, one emitter antenna at the external side of the skin and the receiver antenna under the ski

  6. Construction of a dog training device with high frequency and high power pulses

    International Nuclear Information System (INIS)

    Viaud Trejos, Rafael Alfonso

    2013-01-01

    An electronic device is built to produce high frequency and high power sound. The device is used in training and control of dogs. Commercial ultrasonic devices used for dog training are analyzed. The best strategies and components of the design are determined from an electronic device to produce sounds in frequency from 15kHz to 50Khz. Effectiveness tests are performed to establish the adequate design of the ultrasonic electronic device. The test results are analyzed to find opportunities of improvement in the design or construction of the device [es

  7. The Impact of Power Switching Devices on the Thermal Performance of a 10 MW Wind Power NPC Converter

    Directory of Open Access Journals (Sweden)

    Ke Ma

    2012-07-01

    Full Text Available Power semiconductor switching devices play an important role in the performance of high power wind energy generation systems. The state-of-the-art device choices in the wind power application as reported in the industry include IGBT modules, IGBT press-pack and IGCT press-pack. Because of significant deviation in the packaging structure, electrical characteristics, as well as thermal impedance, these available power switching devices may have various thermal cycling behaviors, which will lead to converter solutions with very different cost, size and reliability performance. As a result, this paper aimed to investigate the thermal related characteristics of some important power switching devices. Their impact on the thermal cycling of a 10 MW three-level Neutral-Point-Clamped wind power converter is then evaluated under various operating conditions; the main focus will be on the grid connected inverter. It is concluded that the thermal performances of the 3L-NPC wind power converter can be significantly changed by the power device technology as well as their parallel configurations.

  8. RESURF power semiconductor devices - Performance and operating limits

    NARCIS (Netherlands)

    Ferrara, A.

    2016-01-01

    Power transmission is the transfer of energy from a generating source to a load which uses the energy to perform useful work. Since the end of the 19th century, electrical power transmission has replaced mechanical power transmission in all long distance applications. The alternating current (AC)

  9. RESURF power semiconductor devices: performance and operating limits

    NARCIS (Netherlands)

    Ferrara, A.

    2016-01-01

    Power transmission is the transfer of energy from a generating source to a load which uses the energy to perform useful work. Since the end of the 19th century, electrical power transmission has replaced mechanical power transmission in all long distance applications. The alternating current (AC)

  10. Automatic control device for the reduction of reactor power

    International Nuclear Information System (INIS)

    Sumida, Susumu; Mizuno, Hiroshi.

    1982-01-01

    Purpose: To early detect troubles in condensate pipeways and feedwater pipeways of BWR-type reactor. Constitution: Detectors are provided to a condensate pipe, a condensator, a low pressure condensate pump, a condensate desalting device and a high pressure condensate pump for constituting condensate pipeways, as well as to a feedwater heater, a feedwater pipe and a feedwater pump for constituting feedwater pipeways. Each of the detectors is connected by way of a lead wire to an abnormal detection and processing device. The abnormal detection and processing device, which are connected to a recycling control device, monitor the input from the detector and sends a control signal to the recycling control system upon calculation of a trouble signal from the detector. (Sekiya, K.)

  11. A flexible super-capacitive solid-state power supply for miniature implantable medical devices.

    Science.gov (United States)

    Meng, Chuizhou; Gall, Oren Z; Irazoqui, Pedro P

    2013-12-01

    We present a high-energy local power supply based on a flexible and solid-state supercapacitor for miniature wireless implantable medical devices. Wireless radio-frequency (RF) powering recharges the supercapacitor through an antenna with an RF rectifier. A power management circuit for the super-capacitive system includes a boost converter to increase the breakdown voltage required for powering device circuits, and a parallel conventional capacitor as an intermediate power source to deliver current spikes during high current transients (e.g., wireless data transmission). The supercapacitor has an extremely high area capacitance of ~1.3 mF/mm(2), and is in the novel form of a 100 μm-thick thin film with the merit of mechanical flexibility and a tailorable size down to 1 mm(2) to meet various clinical dimension requirements. We experimentally demonstrate that after fully recharging the capacitor with an external RF powering source, the supercapacitor-based local power supply runs a full system for electromyogram (EMG) recording that consumes ~670 μW with wireless-data-transmission functionality for a period of ~1 s in the absence of additional RF powering. Since the quality of wireless powering for implantable devices is sensitive to the position of those devices within the RF electromagnetic field, this high-energy local power supply plays a crucial role in providing continuous and reliable power for medical device operations.

  12. Method and device allowing a more rational exploitation of electrical power-stations. [energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Mascarello, J

    1974-04-12

    Description is given of a device permitting a more rational exploitation of electrical power stations characterized by the fact that, while electric power available during slack hours is used for pressurizing air (the pressurized air being stored in tanks), the electric power available during slack days is used for generating hydrogen from water, the hydrogen being stored in other tanks. Combustion of the stored hydrogen by the stored air is used for generating electric power during electric power consumption peak-periods.

  13. Performance of FACTS Devices for Power System Stability

    Directory of Open Access Journals (Sweden)

    Bhupendra Sehgal

    2015-09-01

    Full Text Available When a power grid is connected to an induction type wind electric generator (WEG, when there is variation in load and wind speed, grid voltage also vary. In this paper, we study what is the impact when there is a variation of load and wind by variation of real power and reactive power consumed by WEG effect of load and wind speed variations on real power supplied and reactive power consumed by the WEG as well as voltage on the grid are studied. The voltage variation in the grid is controlled by reactive power compensation using shunt connected Static VAR Compensator (SVC comprising Thyristor Controlled Reactor (TCR and Fixed Capacitor (FC. With the help of Fuzzy Logic Controller (FLC, TCR is operated automatically.

  14. REACTIVE POWER DEVICES IN SYSTEMS OF ELECTRIC TRACTION

    Directory of Open Access Journals (Sweden)

    M. O. Kostin

    2010-04-01

    Full Text Available A comparative characteristic of different concepts and expressions for determination of reactive power in the circuits with non-sinusoidal electric values has been given. For the first Ukrainian electric locomotives of DE1 type with the system of DC electric traction, the values of reactive power after Budeany, Fryze, and also the differential, integral and generalized reactive powers have been determined. Some measures on reducing its consumption by the DC electric rolling stock have been suggested.

  15. Device for the nuclear reactor automatic start-up and power control

    International Nuclear Information System (INIS)

    Nikiforov, B.N.; Volkov, A.V.; Ogon'kov, A.I.

    1978-01-01

    A description and flowsheet of a reactor start-up and power-control automatic device containing no nonlinear elements with a relay characteristic are presented. The device consists of two independent channels for measuring the physical power and time (period) constant of the reactor. Requirements for the device are considered, based on the condition of a minimum permissible number of a servomechanism operations due to fluctuations of an input signal which appear because of the statistical nature of processes taking place in the reactor. It is noted that the threshold amplifier used in the device allows a considerable decrease of the reactor start-up time

  16. Application of Devices and Systems Designed for Power Quality Monitoring and Assessment

    Directory of Open Access Journals (Sweden)

    Wiesław Gil

    2014-03-01

    Full Text Available The paper presents the problems associated with increasing demands on the equipment and systems for power quality assessment (PQ, installed at power substations. Difficulties are signaled due to current lack of standards defining the test methodology of measuring devices. The necessary device properties and the structure of a large system operated in real time and designed to assess the PQ are discussed. The usefulness of multi-channel analyzers featuring the identification and registration of transients is pointed out. The desirability of synchrophasor assessment implementation and device integration by standard PN-EN 61850 with other SAS devices is also justified.

  17. Modelling aluminium wire bond reliability in high power OMP devices

    NARCIS (Netherlands)

    Kregting, R.; Yuan, C.A.; Xiao, A.; Bruijn, F. de

    2011-01-01

    In a RF power application such as the OMP, the wires are subjected to high current (because of the high power) and high temperature (because of the heat from IC and joule-heating from the wire itself). Moreover, the wire shape is essential to the RF performance. Hence, the aluminium wire is

  18. SiC materials: a semiconductor family for the next century

    Science.gov (United States)

    Camassel, Jean; Contreras, Sylvie; Robert, Jean-Louis

    2000-03-01

    The current status of SiC semiconductor materials is reviewed, with emphasize on forthcoming applications. In a first part one focuses on the most important physical properties. Then, power device and micro-opto-electronic applications, using both 4H and 6H-SiC, are presented. Technological problems which have to be solved in order to realize simple planar device are considered. Emphasize is set on the French and European efforts, and on the USA and Japan's ones. In a second part, one deals with advanced high temperature industrial sensor applications. Interest for cubic 3C-SiC eposited on Silicon On Insulator (SOI) is demonstrated and results of comparative examinations of different 3CSiC/SOI materials are briefly given.

  19. Research on export system of marine nuclear power device

    International Nuclear Information System (INIS)

    Fu Mingyu; Bian Xinqian; Shi Ji; Xin Chengdong; Wei Dong

    2002-01-01

    A marine nuclear power plant simulation system is founded, and a management expert system, which can administer and diagnose the typical faults, is constituted by the intelligent expert theory. This real-time expert system can analyze the reason of the typical fault caused by the nuclear power plant practically running and give the best solvent by the expert knowledge reasoning in the repository; a neural network fault inspection and diagnosis expert system which can inspect every equipment continually and give the faults diagnosis result based on the inspective dates is established. Based on the three hierarchical architecture, the operation performance is improved very much by using of the neural network fault inspection and diagnosis expert system to inspect and diagnose the nuclear power plant faults and the management expert system to supervise the nuclear power plant running. The expert system research can give guidance for the marine nuclear power plant safety operation

  20. Short-circuit ruggedness assessment of a 1.2 kV/180 A SiC MOSFET power module

    DEFF Research Database (Denmark)

    Ionita, Claudiu; Nawaz, Muhammad; Ilves, Kalle

    2017-01-01

    is typically encountered in applications for devices of these ratings. Five modules were failed in total, with a critical short-circuit energy, Ecr ranging from 7.3 J to 9.7 J. The failure mechanism is generally the thermal runaway. Prior to failure, a decrease in VGS can be observed which is an indication...

  1. Vertically cross-linked and porous CoNi2S4 nanosheets-decorated SiC nanowires with exceptional capacitive performance as a free-standing electrode for asymmetric supercapacitors

    Science.gov (United States)

    Zhao, Jian; Li, Zhenjiang; Zhang, Meng; Meng, Alan; Li, Qingdang

    2016-11-01

    In this paper, a simple, low-cost and mild hydrothermal technology of growing vertically cross-linked ternary nickel cobalt sulfides nanosheets (CoNi2S4 NSs) with porous characteristics on SiC nanowires (SiC NWs) supporters with outstanding resistances to oxidation and corrosion, good conductivity and large specific surface area deposited directly on carbon cloth (CC) is successfully developed, forming a new family of free-standing advanced hybrid electrode for asymmetric supercapacitors (ASCs). Such integrated electrode (SiC NWs@CoNi2S4 NSs) manifests intriguing electrochemical characteristics such as high specific capacity (231.1 mA h g-1 at 2 A g-1) and rate capability due to the synergistic effect of SiC NWs and CoNi2S4 NSs with unique morphology. Additionally, an asymmetric supercapacitor is also assembled via using this special hybrid architectures as positive electrode and activated carbon (AC) on Ni foam (NF) as negative electrode, and it can yield a high energy density of 57.8 W h kg-1 with a power density of 1.6 kW kg-1 and long cycling lifespan. This study constitutes an emerging attractive strategy to reasonably design and fabricate novel SiC NWs-based nanostructured electrodes with enhanced capacity, which holds great potential to be the candidate of electrode materials for environmentally benign as well as high-performance energy storage devices.

  2. Safety device and machine system of nuclear power plant

    International Nuclear Information System (INIS)

    1978-10-01

    It introduces principle and kinds of heat power including heat balance and nuclear power. It explains a lot of technical terms about the nuclear power system, which are primary loop, reactor, steam generator, primary coolant pump and pressurizer in PWR, chemical and volume control system, component cooling system, safety injection system, and spent fuel cooling and storage system in auxiliary system, liquid solid and gaseous waste disposal system in radwaste disposal, gland sealing system, turbine instrumentation, turning gear, hydrogen cooling system, condenser, feedwater heater, degenerate heater, auxiliary heat exchanger, centrifugal pump, rotary reciprocating and tank and pressure vessel.

  3. Research Progress of Optical Fabrication and Surface-Microstructure Modification of SiC

    Directory of Open Access Journals (Sweden)

    Fang Jiang

    2012-01-01

    Full Text Available SiC has become the best candidate material for space mirror and optical devices due to a series of favorable physical and chemical properties. Fine surface optical quality with the surface roughness (RMS less than 1 nm is necessary for fine optical application. However, various defects are present in SiC ceramics, and it is very difficult to polish SiC ceramic matrix with the 1 nm RMS. Surface modification of SiC ceramics must be done on the SiC substrate. Four kinds of surface-modification routes including the hot pressed glass, the C/SiC clapping, SiC clapping, and Si clapping on SiC surface have been reported and reviewed here. The methods of surface modification, the mechanism of preparation, and the disadvantages and advantages are focused on in this paper. In our view, PVD Si is the best choice for surface modification of SiC mirror.

  4. State-of-the-art technologies of gallium oxide power devices

    Science.gov (United States)

    Higashiwaki, Masataka; Kuramata, Akito; Murakami, Hisashi; Kumagai, Yoshinao

    2017-08-01

    Gallium oxide (Ga2 O3 ) has gained increased attention for power devices due to its superior material properties and the availability of economical device-quality native substrates. This review illustrates recent advances in Ga2 O3 device technologies, beginning with an overview of the social circumstances that motivate the development of new-generation switching devices. Following an introduction to the material properties of Ga2 O3 from the viewpoint of power electronics, growth technologies of Ga2 O3 bulk single crystals and epitaxial thin films are discussed. The fabrication and performance of state-of-the-art Ga2 O3 transistors and diodes are then described. We conclude by identifying the directions and challenges of Ga2 O3 power device development in the near future.

  5. Multilayer mirrors as power filters in insertion device beamlines

    International Nuclear Information System (INIS)

    Kortright, J.B.; DiGennaro, R.S.

    1988-08-01

    The power-filtering capabilities of multilayer band-pass x-ray mirrors relative to total reflection low-pass mirrors is presented. Results are based on calculations assuming proposed wiggler sources on the upcoming generation of low energy (1.5 GeV) and high energy (7.0 GeV) synchrotron radiation sources. Results show that multilayers out-perform total reflection mirrors in terms of reduction in reflected power by roughly an order of magnitude, with relatively small increases in total absorbed power and power density over total reflection mirrors, and with comparable reflected flux values. Various aspects of this potential application of multilayer x-ray optics are discussed. 13 refs., 3 figs., 1 tab

  6. Application of energy storage devices in power systems

    African Journals Online (AJOL)

    user

    paper concentrates on performance benefits of adding energy storage to power ..... Because of geographical, environmental, and cost constraints, construction of pumped .... transport, in Information Day on Non-Nuclear Energy RTD, Brussels.

  7. A Wave Power Device with Pendulum Based on Ocean Monitoring Buoy

    Science.gov (United States)

    Chai, Hui; Guan, Wanchun; Wan, Xiaozheng; Li, Xuanqun; Zhao, Qiang; Liu, Shixuan

    2018-01-01

    The ocean monitoring buoy usually exploits solar energy for power supply. In order to improve power supply capacity, this paper proposes a wave power device according to the structure and moving character of buoy. The wave power device composes of pendulum mechanism that converts wave energy into mechanical energy and energy storage mechanism where the mechanical energy is transferred quantitatively to generator. The hydrodynamic equation for the motion of buoy system with generator devise is established based on the potential flow theory, and then the characteristics of pendulum motion and energy conversion properties are analysed. The results of this research show that the proposed wave power devise is able to efficiently and periodically convert wave energy into power, and increasing the stiffness of energy storage spring is benefit for enhancing the power supply capacity of the buoy. This study provides a theory reference for the development of technology on wave power generator for ocean monitoring buoy.

  8. Grafted SiC nanocrystals

    DEFF Research Database (Denmark)

    Saini, Isha; Sharma, Annu; Dhiman, Rajnish

    2017-01-01

    ), raman spectroscopy and X-ray diffraction (XRD) measurements. UV–Visible absorption spectroscopy was used to study optical properties such as optical energy gap (Eg), Urbach's energy (Eu), refractive index (n), real (ε1) and imaginary (ε2) parts of dielectric constant of PVA as well as PVA......Polyvinyl alcohol (PVA) grafted SiC (PVA-g-SiC)/PVA nanocomposite was synthesized by incorporating PVA grafted silicon carbide (SiC) nanocrystals inside PVA matrix. In-depth structural characterization of resulting nanocomposite was carried out using fourier transform infrared spectroscopy (FTIR...

  9. On the fundamental performance of the floating offshore wave power device (FOWAD)

    International Nuclear Information System (INIS)

    Hotta, H.; Washio, Y.; Miyazaki, T.

    1990-01-01

    This paper reports on the wave power absorption, wave dissipation, mooring line tension and oscillation in regular and irregular (long created and short created) waves of the floating offshore wave power device (FOWAD) that were measured and analyzed by a scale model test in a wave tank. FOWAD is an oscillating water column type device equipped with air turbine generators, and air chambers facing the waves. Therefore, it belongs in the close of terminator type wave power devices. It has several projecting walls in front of each air chamber, several buoyancy compartments behind each chamber and stabilizer at the keel. The measured data indicates that, the performance and stability were improved in comparison with former terminator type devices, FOWAD absorbed about 30% of wave power and mooring line tension was within the limits of safety even in rough seas. Nevertheless the performance for dissipation of waves can be improved. This paper describes on the results of the model test and subsequent analysis

  10. Energy transmission and power sources for mechanical circulatory support devices to achieve total implantability.

    Science.gov (United States)

    Wang, Jake X; Smith, Joshua R; Bonde, Pramod

    2014-04-01

    Left ventricular assist device therapy has radically improved congestive heart failure survival with smaller rotary pumps. The driveline used to power today's left ventricular assist devices, however, continues to be a source of infection, traumatic damage, and rehospitalization. Previous attempts to wirelessly power left ventricular assist devices using transcutaneous energy transfer systems have been limited by restrictions on separation distance and alignment between the transmit and receive coils. Resonant electrical energy transfer allows power delivery at larger distances without compromising safety and efficiency. This review covers the efforts to wirelessly power mechanical circulatory assist devices and the progress made in enhancing their energy sources. Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  11. High-Efficiency, Nanowire Based Thermoelectric Devices for Radioisotope Power Conversion, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I proposal responds to topic S3.03 of the 2010 NASA SBIR solicitation, for Power Generation and Conversion. Thermoelectric devices offer a simple and...

  12. Load power device and system for real-time execution of hierarchical load identification algorithms

    Science.gov (United States)

    Yang, Yi; Madane, Mayura Arun; Zambare, Prachi Suresh

    2017-11-14

    A load power device includes a power input; at least one power output for at least one load; and a plurality of sensors structured to sense voltage and current at the at least one power output. A processor is structured to provide real-time execution of: (a) a plurality of load identification algorithms, and (b) event detection and operating mode detection for the at least one load.

  13. Use of UPFC device controlled by fuzzy logic controllers for decoupled power flow control

    Directory of Open Access Journals (Sweden)

    Ivković Sanja

    2014-01-01

    Full Text Available This paper investigates the possibility of decoupled active and reactive power flow control in a power system using a UPFC device controlled by fuzzy logic controllers. A Brief theoretical review of the operation principles and applications of UPFC devices and design principles of the fuzzy logic controller used are given. A Matlab/Simulink model of the system with UPFC, the fuzzy controller setup, and graphs of the results are presented. Conclusions are drawn regarding the possibility of using this system for decoupled control of the power flow in power systems based on analysis of these graphs.

  14. Earthquake proof device for nuclear power plant building

    International Nuclear Information System (INIS)

    Okada, Yasuo.

    1991-01-01

    The structure of the present invention enables three dimensional vibration proof, i.e., in horizontal and vertical directions of a reactor container building. That is, each of the reactor container building and a reactor auxiliary building is adapted as an independent structure. The periphery of the reactor container building is surrounded by the reactor auxiliary building. The reactor auxiliary building is supported against the ground by way of a horizontal vibration proof device. The reactor container building is supported against the ground by way of a three-dimensional vibration proof device that prevents vibrations in both of the horizontal directions, and the vertical directions. The reactor container building is connected to the auxiliary building by way of a vertical vibration proof device. With such a constitution, although the reactor container building is vibration proof against both of the horizontal and the vertical vibrations, the vertical vibration proofness is an extension of inherent vertical vibration period. Accordingly, the head of the building undergoes rocking vibrations. However, since the reactor container building is connected to the reactor auxiliary building, the rocking vibrations are prevented by the reactor auxiliary building. As a result, safety upon occurrence of an earthquakes can be ensured. (I.S.)

  15. Optimizing MEMS-Based Storage Devices for Mobile Battery-Powered Systems

    NARCIS (Netherlands)

    Khatib, M.G.; Hartel, Pieter H.

    An emerging storage technology, called MEMS-based storage, promises nonvolatile storage devices with ultrahigh density, high rigidity, a small form factor, and low cost. For these reasons, MEMS-based storage devices are suitable for battery-powered mobile systems such as PDAs. For deployment in such

  16. Fabrication and Characterization of Li-ion Electrodes for High-Power Energy Storage Devices

    OpenAIRE

    Lai, Chun-Han

    2017-01-01

    Renewable energy technologies have been a rapidly emerging option to meet future energy demand. However, their systems require stable, high-power storage devices to overcome fluctuating energy outputs for consistent distribution. Since traditional Li-ion batteries (LIB) are not considered to be capable of fast charging and discharging, we have to develop devices with new chemistry for high-power operation. This dissertation focuses on the development of supercapacitors and high-rate batteries...

  17. The ''controbloc'', a programmable automatic device for the 1,300 MW generation of power stations

    International Nuclear Information System (INIS)

    Pralus, B.; Winzelle, J.C.

    1983-01-01

    Technological progress in the field of microelectronics has led to the development of an automatic control device, the ''controbloc'', for operating and controlling nuclear power plants. The ''controbloc'' will be used in automatic systems with a high degree of safety and versatility and is now being installed in the first of the new generation 1,300 MW power stations. The main characteristics of the device and the evaluation tests which have been carried out are described [fr

  18. Palladium transport in SiC

    International Nuclear Information System (INIS)

    Olivier, E.J.; Neethling, J.H.

    2012-01-01

    Highlights: ► We investigate the reaction of Pd with SiC at typical HTGR operating temperatures. ► The high temperature mobility of palladium silicides within polycrystalline SiC was studied. ► Corrosion of SiC by Pd was seen in all cases. ► The preferential corrosion and penetration of Pd along grain boundaries in SiC was found. ► The penetration and transport of palladium silicides in SiC along grain boundaries was found. - Abstract: This paper reports on a transmission electron microscopy (TEM) and scanning electron microscopy (SEM) study of Pd corroded SiC. The reaction of Pd with different types of SiC at typical HTGR operating temperatures was examined. In addition the high temperature mobility of palladium silicides within polycrystalline SiC was investigated. The results indicated corrosion of the SiC by Pd in all cases studied. The corrosion leads to the formation of palladium silicides within the SiC, with the predominant phase found being Pd 2 Si. Evidence for the preferential corrosion and penetration of Pd along grain boundaries in polycrystalline SiC was found. The penetration and transport, without significant corrosion, of palladium silicides into polycrystalline SiC along grain boundaries was also observed. Implications of the findings with reference to the use of Tri Isotropic particles in HTGRs will be discussed.

  19. Palladium transport in SiC

    Energy Technology Data Exchange (ETDEWEB)

    Olivier, E.J., E-mail: jolivier@nmmu.ac.za [Centre for High Resolution Transmission Electron Microscopy, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Neethling, J.H. [Centre for High Resolution Transmission Electron Microscopy, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer We investigate the reaction of Pd with SiC at typical HTGR operating temperatures. Black-Right-Pointing-Pointer The high temperature mobility of palladium silicides within polycrystalline SiC was studied. Black-Right-Pointing-Pointer Corrosion of SiC by Pd was seen in all cases. Black-Right-Pointing-Pointer The preferential corrosion and penetration of Pd along grain boundaries in SiC was found. Black-Right-Pointing-Pointer The penetration and transport of palladium silicides in SiC along grain boundaries was found. - Abstract: This paper reports on a transmission electron microscopy (TEM) and scanning electron microscopy (SEM) study of Pd corroded SiC. The reaction of Pd with different types of SiC at typical HTGR operating temperatures was examined. In addition the high temperature mobility of palladium silicides within polycrystalline SiC was investigated. The results indicated corrosion of the SiC by Pd in all cases studied. The corrosion leads to the formation of palladium silicides within the SiC, with the predominant phase found being Pd{sub 2}Si. Evidence for the preferential corrosion and penetration of Pd along grain boundaries in polycrystalline SiC was found. The penetration and transport, without significant corrosion, of palladium silicides into polycrystalline SiC along grain boundaries was also observed. Implications of the findings with reference to the use of Tri Isotropic particles in HTGRs will be discussed.

  20. Power control device for heavy water moderated reactor

    International Nuclear Information System (INIS)

    Matsushima, Hidesuke; Masuda, Hiroyuki.

    1978-01-01

    Purpose: To improve self controllability of a nuclear power plant, as well as enable continuous power level control by a controlled flow of moderators in void pipes provided in a reactor core. Constitution: Hollow void pipes are provided in a reactor core to which a heavy water recycle loop for power control, a heavy water recycle pump for power control, a heavy water temperature regulator and a heavy water flow rate control valve for power control are connected in series to constitute a heavy water recycle loop for flowing heavy water moderators. The void ratio in each of the void pipes are calculated by a process computer to determine the flow rate and the temperature for the recycled heavy water. Based on the above calculation result, the heavy water temperature regulator is actuated by way of a temperature setter at the heavy water inlet and the heavy water flow rate is controlled by the actuation of the heavy water flow rate control valve. (Kawakami, Y.)

  1. Short-time action electric generators to power physical devices

    International Nuclear Information System (INIS)

    Glebov, I.A.; Kasharskij, Eh.G.; Rutberg, F.G.; Khutoretskij, G.M.

    1982-01-01

    Requirements to be met by power-supply sources of the native electrophysical facilities have been analyzed and trends in designing foreign electric machine units of short-time action have been considered. Specifications of a generator, manufactured in the form of synchronous bipolar turbogenerator with an all-forged rotor with indirect air cooling of the rotor and stator windings are presented. Front parts of the stator winding are additionally fixed using glass-textolite rings, brackets and gaskets. A flywheel, manufactured in the form of all-forged steel cylinder is joined directly with the generator rotor by means of a half-coupling. An acceleration asynchronous engine with a phase rotor of 4 MW nominal capacity is located on the opposite side of the flywheel. The generator peak power is 242 MVxA; power factor = 0.9; energy transferred to the load 5per 1 pulse =00 MJ; the flywheel weight 81 t

  2. Temperature control of power semiconductor devices in traction applications

    Science.gov (United States)

    Pugachev, A. A.; Strekalov, N. N.

    2017-02-01

    The peculiarity of thermal management of traction frequency converters of a railway rolling stock is highlighted. The topology and the operation principle of the automatic temperature control system of power semiconductor modules of the traction frequency converter are designed and discussed. The features of semiconductors as an object of temperature control are considered; the equivalent circuit of thermal processes in the semiconductors is suggested, the power losses in the two-level voltage source inverters are evaluated and analyzed. The dynamic properties and characteristics of the cooling fan induction motor electric drive with the scalar control are presented. The results of simulation in Matlab are shown for the steady state of thermal processes.

  3. Enersave API: Android-based power-saving framework for mobile devices

    Directory of Open Access Journals (Sweden)

    A.M. Muharum

    2017-06-01

    Full Text Available Power consumption is a major factor to be taken into consideration when using mobile devices in the IoT field. Good Power management requires proper understanding of the way in which it is being consumed by the end-devices. This paper is a continuation of the work in Ref. [1] and proposes an energy saving API for the Android Operating System in order to help developers turn their applications into energy-aware ones. The main features heavily used for building smart applications, greatly impact battery life of Android devices and which have been taken into consideration are: Screen brightness, Colour scheme, CPU frequency, 2G/3G network, Maps, Low power localisation, Bluetooth and Wi-Fi. The assessment of the power-saving API has been performed on real Android devices and also compared to the most powerful power-saving applications – DU Battery Saver and Battery Saver 2016 – currently available on the Android market. Comparisons demonstrate that the Enersave API has a significant impact on power saving when incorporated in android applications. While DU Battery Saver and Battery Saver 2016 help saving 22.2% and 40.5% of the battery power respectively, the incorporation of the Enersave API in android applications can help save 84.6% of battery power.

  4. Columnar transmitter based wireless power delivery system for implantable device in freely moving animals.

    Science.gov (United States)

    Eom, Kyungsik; Jeong, Joonsoo; Lee, Tae Hyung; Lee, Sung Eun; Jun, Sang Bum; Kim, Sung June

    2013-01-01

    A wireless power delivery system is developed to deliver electrical power to the neuroprosthetic devices that are implanted into animals freely moving inside the cage. The wireless powering cage is designed for long-term animal experiments without cumbersome wires for power supply or the replacement of batteries. In the present study, we propose a novel wireless power transmission system using resonator-based inductive links to increase power efficiency and to minimize the efficiency variations. A columnar transmitter coil is proposed to provide lateral uniformity of power efficiency. Using this columnar transmitter coil, only 7.2% efficiency fluctuation occurs from the maximum transmission efficiency of 25.9%. A flexible polymer-based planar type receiver coil is fabricated and assembled with a neural stimulator and an electrode. Using the designed columnar transmitter coil, the implantable device successfully operates while it moves freely inside the cage.

  5. Optically-gated Non-latched High Gain Power Device

    Science.gov (United States)

    2008-11-21

    doping level. • In the structure of Fig. 6b, the effective P-body length for the carriers traveling from the NT1 " source to drain is dependent on the...photomask picture of a single cell of the prototype device in close detail with all the layers visible. The source metal, N* source and P-body rectangles...drain mask layer P-base mask layer N+ source mask layer Source metal mask layer Fig. 19: A detailed close-up of the photomask for a single cell of

  6. Monitor and control device in a nuclear power plant

    International Nuclear Information System (INIS)

    Neda, Toshikatsu.

    1980-01-01

    Purpose: To facilitate and ensure monitor and control, as well as improve the operation efficiency and save man power, by render the operation automatic utilizing a process computer and centralizing the monitor and control functions. Constitution: All of the operations from the start up to stop in a nuclear power plant are conducted by way of a monitor and control board. The process data for the nuclear power plant are read into the process computer and displayed on a CRT display. Controls are carried out respectively for the control rod on a control rod panel, for the feedwater rate on a feedwater control panel, for the recycling flow rate on a recycling control panel and for the turbine generator on a turbine control panel. When the operation is conducted by an automatic console, operation signals from the console are imputted into the process computer and the state of the power plant is monitored and automatic operation is carried out based on the operation signals and from signals from each of the panels. (Moriyama, K.)

  7. Wireless power transfer for electric vehicles and mobile devices

    CERN Document Server

    Rim, Chun T

    2017-01-01

    From mobile, cable-free re-charging of electric vehicles, smart phones and laptops to collecting solar electricity from orbiting solar farms, wireless power transfer (WPT) technologies offer consumers and society enormous benefits. Written by innovators in the field, this comprehensive resource explains the fundamental principles and latest advances in WPT and illustrates key applications of this emergent technology.

  8. A Review of Electronic Inductor Technique for Power Factor Correction in Three-Phase Adjustable Speed Drives

    DEFF Research Database (Denmark)

    Davari, Pooya; Yang, Yongheng; Zare, Firuz

    2016-01-01

    (SiC) power devices. Moreover, the influence of partial loading on component sizing in Adjustable Speed Drives (ASDs) is studied. Finally the analytical loss modelling of power switches is utilized for efficiency measurement. The theoretical analyses are verified by experimental benchmarking in an ASD...

  9. Water quality improving device of nuclear power plant

    International Nuclear Information System (INIS)

    Mori, Tsuguo.

    1994-01-01

    In the device of the present invention, the amount of an oxygen injected to an inlet of a recombiner is automatically controlled by detecting an oxygen concentration at the exit of the recombiner. Accordingly, the range for the concentration of dissolved oxygen at the exit of the recombiner is appropriately maintained. That is, the device of the present invention comprises a hydrogen injection means, hydrogen concentration measuring means, oxygen injection means, oxygen concentration measuring means and control means. If a hydrogen gas is injected to condensates which are to be coolants of the reactor, it is combined with the dissolved oxygen in the coolants. Excessive hydrogen in this case is measured by an off-gas system, and oxygen of an amount corresponding to the amount for combining the excessive hydrogen is injected to the inlet of the recombiner. The oxygen concentration at the exit of the recombiner is measured. If the result of the measurement is out of a predetermined range, the injection amount of oxygen is increased or decreased to conduct automatic control so that oxygen is within a predetermined range. As a result, the improvement for the water quality of the reactor coolants and processing of the excessive hydrogen gas can be conducted smoothly, stably and safely. (I.S.)

  10. Development of standard technical report on using and selecting wireless device in nuclear power plants

    International Nuclear Information System (INIS)

    Koo, I. S.; Hong, S. B.; Cho, J. W.

    2011-11-01

    1. Purpose · Development of IEC technical report on wireless device using in nuclear power plants 2. Contents · IEC technical reports of draft for circulation and final draft for next planary meeting · Case study on experiment of wireless devices 3. Implementation methods · Preparation of first draft with experts group, its circulation, discussions on the results of the circulation · Organizing three teams such as preparation, reviews and experiment 4. Results · Maintenance cost will be reduced with application of the wireless technologies in nuclear power plants · Commercial wireless devices will be developed before standard is issued

  11. Analysis and evaluation of the power amplifier device

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y. K.; Ryu, J. W. [Kongju National University, Gongju (Korea, Republic of)

    2011-11-15

    We developed a master oscillator power amplifier (MOPA) type fiber amplifier for the separation of the Ca-48 isotope by using a fiber laser. The ytterbium (Yb)-doped end-capped rod-type photonic crystal fiber (PCF) was used as a gain medium of MOPA amplifier. The PCFs used in our experiments were a 56-cm and an 81-cm rod-type end-capped Yb-doped double-clad PM fibers 'DC-285/100-PM-Yb-Rod', with a 100-{mu}m core (NA 0.02) and a 285-{mu}m cladding (NA 0.6) fabricated by NKT Photonics. The mode field diameter (MFD) of the rod-type PCF was 75-{mu}m, and an absorption efficiency of 30 dB/m at 976 nm and a low NA 0.02 helped to sustain the excellent lasing beam quality. We obtained an output power of 112 W at a pump power of 380 W with a repetition rate of 150 kHz. The measured pulse width was 13 ns at 150 kHz, 1056 nm. The laser beam quality shows a single mode amplification characteristics with a beam quality factor values of M2 are 2 -3. The PCF launching efficiency reached a maximum value of 86.7% with an average efficiencies of above 80%. At a pump power of 250 W and seed power input of 4 W, the CW PCF amplifier was found to generate average output powers of 138 W, 110 W, and 82 W at 1056-nm, 1070-nm, and 1089-nm wavelengths, respectively. The amplified PCF output beam had a line width of 70 MHz full width at half maximum (FWHM). These PCF amplified beams had good beam qualities with M2values of less than 1.8 at all three wavelengths. The gain saturation seed input power in the 81-cm PCF was found to be {approx}6 W at 1056 nm. The temperature of the PCF core reached over 230 .deg. C at the pumping section of the PCF. The temperatures of the end-cap heads on both the pumping and the output end-cap sides were 81.4 .deg. C and 35.7 .deg. C, respectively. The PCF amplifier maintained good polarization mode characteristics with an average DOP of over 87%. The slight decrease in the DOP oat output powers over 170 W output power may have been caused by a

  12. Conceptual design and simulation investigation of an electronic cooling device powered by hot electrons

    International Nuclear Information System (INIS)

    Su, Guozhen; Zhang, Yanchao; Cai, Ling; Su, Shanhe; Chen, Jincan

    2015-01-01

    Most electronic cooling devices are powered by an external bias applied between the cold and the hot reservoirs. Here we propose a new concept of electronic cooling, in which cooling is achieved by using a reservoir of hot electrons as the power source. The cooling device incorporates two energy filters with the Lorentzian transmission function to respectively select low- and high-energy electrons for transport. Based on the proposed model, we analyze the performances of the device varying with the resonant levels and half widths of two energy filters and establish the optimal configuration of the cooling device. It is believed that such a novel device may be practically used in some nano-energy fields. - Highlights: • A new electronic cooling device powered by hot electrons is proposed. • Two energy filters are employed to select the electrons for transport. • The effects of the resonant levels and half widths of two filters are discussed. • The maximum cooling power and coefficient of performance are calculated. • The optimal configuration of the cooling device is determined.

  13. Ship nuclear power device of cable aging management

    International Nuclear Information System (INIS)

    Wei Hua; Chen Miao; Chen Tao

    2012-01-01

    Cable for marine nuclear power plant continuous delivery of electrical energy. Cable is mostly in the high temperature and strong radiation and harsh working environment, and can not be replaced in the lifetime This should be the cable aging management methods through research, maintenance and repair program to provide a scientific basis. Cable aging management approach for a number of different levels of cable management at different levels, relying on computers and other modern tools, the use of information management database software maintenance of the cable through the science of aging control. Cable Aging Management including the scope of cable aging management, classification management basis and used for different levels of management supervision and implementation of means testing approach. Application of the ship that has the operational management science, both planned maintenance to improve the science, but also improves the efficiency of aging management. This management method can be extended to nuclear power plants of cable aging management. (authors)

  14. High power RF window deposition apparatus, method, and device

    Science.gov (United States)

    Ives, Lawrence R.; Lucovsky, Gerald; Zeller, Daniel

    2017-07-04

    A process for forming a coating for an RF window which has improved secondary electron emission and reduced multipactor for high power RF waveguides is formed from a substrate with low loss tangent and desirable mechanical characteristics. The substrate has an RPAO deposition layer applied which oxygenates the surface of the substrate to remove carbon impurities, thereafter has an RPAN deposition layer applied to nitrogen activate the surface of the substrate, after which a TiN deposition layer is applied using Titanium tert-butoxide. The TiN deposition layer is capped with a final RPAN deposition layer of nitridation to reduce the bound oxygen in the TiN deposition layer. The resulting RF window has greatly improved titanium layer adhesion, reduced multipactor, and is able to withstand greater RF power levels than provided by the prior art.

  15. Cavitation preventing device in a nuclear power plant

    International Nuclear Information System (INIS)

    Hirose, Masao.

    1983-01-01

    Purpose: To prevent the generation of cavitation upon loss of feedwater flow rate in BWR nuclear power plant by reliably and rapidly tripping a recycling pump. Constitution: Two phase streams from a nuclear reactor are divided into main steams and saturated water in a steam drum. The deviation between the corresponding flow rate of the main steams and the feedwater flow rate of the feedwater pump sending condensates to the steam drum, as well as the continuing period of the deviation are monitored. Then, if it is detected that both of the deviation and the continuing period thereof exceed specified levels, the recycling pump feeding the saturated water to the reactor is tripped. In this way, the recycling pump can be tripped rapidly and reliably upon loss of feedwater flow rate, whereby the generation of the cavitation can be prevented and the normal operation of the nuclear power plant can be insured. (Moriyama, K.)

  16. Liquid-poison type power controlling device for nuclear reactor

    International Nuclear Information System (INIS)

    Horiuchi, Tetsuo; Yamanari, Shozo; Sugisaki, Toshihiko; Goto, Hiroshi.

    1981-01-01

    Purpose: To improve the safety and the operability of a nuclear reactor by adjusting the density of liquid poison. Constitution: The thermal expansion follow-up failure between cladding and a pellet upon abrupt and local variations of the power is avoided by adjusting the density of liquid poison during ordinary operation in combination with a high density liquid poison tank and a filter and smoothly controlling the reactor power through a pipe installed in the reactor core. The high density liquid poison is abruptly charged in to the reactor core under relatively low pressure through the tube installed in the reactor core at the time of control rod insertion failure in an accident, thereby effectively shutting down the reactor and improving the safety and the operability of the reactor. (Yoshihara, H.)

  17. Advanced Thermophotovoltaic Devices for Space Nuclear Power Systems

    International Nuclear Information System (INIS)

    Wernsman, Bernard; Mahorter, Robert G.; Siergiej, Richard; Link, Samuel D.; Wehrer, Rebecca J.; Belanger, Sean J.; Fourspring, Patrick; Murray, Susan; Newman, Fred; Taylor, Dan; Rahmlow, Tom

    2005-01-01

    Advanced thermophotovoltaic (TPV) modules capable of producing > 0.3 W/cm2 at an efficiency > 22% while operating at a converter radiator and module temperature of 1228 K and 325 K, respectively, have been made. These advanced TPV modules are projected to produce > 0.9 W/cm2 at an efficiency > 24% while operating at a converter radiator and module temperature of 1373 K and 325 K, respectively. Radioisotope and nuclear (fission) powered space systems utilizing these advanced TPV modules have been evaluated. For a 100 We radioisotope TPV system, systems utilizing as low as 2 general purpose heat source (GPHS) units are feasible, where the specific power for the 2 and 3 GPHS unit systems operating in a 200 K environment is as large as ∼ 16 We/kg and ∼ 14 We/kg, respectively. For a 100 kWe nuclear powered (as was entertained for the thermoelectric SP-100 program) TPV system, the minimum system radiator area and mass is ∼ 640 m2 and ∼ 1150 kg, respectively, for a converter radiator, system radiator and environment temperature of 1373 K, 435 K and 200 K, respectively. Also, for a converter radiator temperature of 1373 K, the converter volume and mass remains less than 0.36 m3 and 640 kg, respectively. Thus, the minimum system radiator + converter (reactor and shield not included) specific mass is ∼ 16 kg/kWe for a converter radiator, system radiator and environment temperature of 1373 K, 425 K and 200 K, respectively. Under this operating condition, the reactor thermal rating is ∼ 1110 kWt. Due to the large radiator area, the added complexity and mission risk needs to be weighed against reducing the reactor thermal rating to determine the feasibility of using TPV for space nuclear (fission) power systems

  18. Reliability improvement in GaN HEMT power device using a field plate approach

    Science.gov (United States)

    Wu, Wen-Hao; Lin, Yueh-Chin; Chin, Ping-Chieh; Hsu, Chia-Chieh; Lee, Jin-Hwa; Liu, Shih-Chien; Maa, Jer-shen; Iwai, Hiroshi; Chang, Edward Yi; Hsu, Heng-Tung

    2017-07-01

    This study investigates the effect of implementing a field plate on a GaN high-electron-mobility transistor (HEMT) to improve power device reliability. The results indicate that the field plate structure reduces the peak electrical field and interface traps in the device, resulting in higher breakdown voltage, lower leakage current, smaller current collapse, and better threshold voltage control. Furthermore, after high voltage stress, steady dynamic on-resistance and gate capacitance degradation improvement were observed for the device with the field plate. This demonstrates that GaN device reliability can be improved by using the field plate approach.

  19. Prospects for the application of GaN power devices in hybrid electric vehicle drive systems

    International Nuclear Information System (INIS)

    Su, Ming; Chen, Chingchi; Rajan, Siddharth

    2013-01-01

    GaN, a wide bandgap semiconductor successfully implemented in optical and high-speed electronic devices, has gained momentum in recent years for power electronics applications. Along with rapid progress in material and device processing technologies, high-voltage transistors over 600 V have been reported by a number of teams worldwide. These advances make GaN highly attractive for the growing market of electrified vehicles, which currently employ bipolar silicon devices in the 600–1200 V class for the traction inverter. However, to capture this billion-dollar power market, GaN has to compete with existing IGBT products and deliver higher performance at comparable or lower cost. This paper reviews key achievements made by the GaN semiconductor industry, requirements of the automotive electric drive system and remaining challenges for GaN power devices to fit in the inverter application of hybrid vehicles. (invited review)

  20. Prospects for the application of GaN power devices in hybrid electric vehicle drive systems

    Science.gov (United States)

    Su, Ming; Chen, Chingchi; Rajan, Siddharth

    2013-07-01

    GaN, a wide bandgap semiconductor successfully implemented in optical and high-speed electronic devices, has gained momentum in recent years for power electronics applications. Along with rapid progress in material and device processing technologies, high-voltage transistors over 600 V have been reported by a number of teams worldwide. These advances make GaN highly attractive for the growing market of electrified vehicles, which currently employ bipolar silicon devices in the 600-1200 V class for the traction inverter. However, to capture this billion-dollar power market, GaN has to compete with existing IGBT products and deliver higher performance at comparable or lower cost. This paper reviews key achievements made by the GaN semiconductor industry, requirements of the automotive electric drive system and remaining challenges for GaN power devices to fit in the inverter application of hybrid vehicles.

  1. Device and Circuit Design Challenges in the Digital Subthreshold Region for Ultralow-Power Applications

    Directory of Open Access Journals (Sweden)

    Ramesh Vaddi

    2009-01-01

    Full Text Available In recent years, subthreshold operation has gained a lot of attention due to ultra low-power consumption in applications requiring low to medium performance. It has also been shown that by optimizing the device structure, power consumption of digital subthreshold logic can be further minimized while improving its performance. Therefore, subthreshold circuit design is very promising for future ultra low-energy sensor applications as well as high-performance parallel processing. This paper deals with various device and circuit design challenges associated with the state of the art in optimal digital subthreshold circuit design and reviews device design methodologies and circuit topologies for optimal digital subthreshold operation. This paper identifies the suitable candidates for subthreshold operation at device and circuit levels for optimal subthreshold circuit design and provides an effective roadmap for digital designers interested to work with ultra low-power applications.

  2. A rotary multimodal hybrid energy harvesting device powered by human motion

    Science.gov (United States)

    Larkin, Miles R.

    This thesis presents a novel hybrid multimodal energy harvesting device consisting of an unbalanced rotary disk that supports two transduction methods, piezoelectric and electromagnetic. The device generates electrical energy from oscillatory motion either orthogonal or parallel to the rotary axis to power electronic devices. Analytical models of the device were developed, from which numerical simulations were performed for several different generator sizes. Two prototypes, 180 mm and 100 mm in diameter, respectively, were fabricated and characterized experimentally with a modal shaker. The 180 mm prototype generated 120 mW from the electromagnetic system at 5 Hz and 0.8g, and 4.23 mW from the piezoelectric system at 20.2 Hz and 0.4g excitation acceleration. Finally, the power generation capabilities of the two prototypes were compared to other similar devices.

  3. Construction of control and instrumentation devices of high voltage power supply of double chamber plasma nitrogen

    International Nuclear Information System (INIS)

    Saminto; Eko Priyono; Sugeng Riyanto

    2013-01-01

    A control and instrumentation devices of high voltage power supply of double chamber plasma nitrogen have been made. This device consists of the software and hardware component. Hardware component consists of SCR phase angle controller LPC-50HDA type, T100MD1616+ PLC, high voltage transformer and voltage rectifier system. Software component used a LADDER program and TBasic serves to control of the high voltage output. The components in these devices have been tested in the double chamber plasma nitrogen. Its performance meet with the design criteria that can supply of plasma nitrogen operation voltage in the range 290 Vdc to 851 Vdc with glow discharge current 0.4 A to 1.4 A. In general it can be said that the control and instrumentation devices of high voltage power supply is ready for use at the double chamber plasma nitrogen device. (author)

  4. Assembling markets for wind power. An inquiry into the making of market devices

    Energy Technology Data Exchange (ETDEWEB)

    Pallesen, T.

    2013-04-15

    This project studies the making of a market for wind power in France. Markets for wind power, as well as markets for other renewable energies, are often referred to as 'political markets: On the one hand, wind power has the potential to reduce CO{sub 2}-emissions and thus stall the effects of electricity generation on climate change; and on the other hand, as an economic good, wind power is said to suffer from 'disabilities', such as high costs, fluctuating and unpredictable generation, etc. Therefore, because of its performance as a good, it is argued that the survival of wind power in the market is premised on different instruments, some of which I will refer to as 'prosthetic devices'. This thesis inquires into two such prosthetic devices: The feed-in tariff and the wind power development zones (ZDE) as they are negotiated and practiced in France, and the ways in which they affect the making of markets for wind power. In this thesis, it is argued that while the two devices frame the price of wind power and the location of turbines, they also affect and address questions of costs, profitability, and efficiency; and as such, they may be investigated as market devices. (Author)

  5. Waveform measurement in mocrowave device characterization: impact on power amplifiers design

    Directory of Open Access Journals (Sweden)

    Roberto Quaglia

    2016-07-01

    Full Text Available This paper describes an example of a measurement setup enabling waveform measurements during the load-pull characterization of a microwave power device. The significance of this measurement feature is highlighted showing how waveform engineering can be exploited to design high efficiency microwave power amplifiers.

  6. Reliability of IGBT-based power devices in the viewpoint of applications in future power supply systems

    International Nuclear Information System (INIS)

    Lutz, J.

    2011-01-01

    IGBT-based high-voltage power devices will be key components for future renewable energy base of the society. Windmills in the range up to 10 MW use converters with IGBTs. HVDC systems with IGBT-based voltage source converters have the advantage of a lower level of harmonics, less efforts for filters and more possibilities for control. The power devices need a lifetime expectation of several ten years. The lifetime is determined by the reliability of the packaging technology. IGBTs are offered packaged in presspacks and modules. The presentation will have the focus on IGBT high power modules. Accelerated power cycling tests for to determine the end-of-life at given conditions and their results are shown. models to calculate the lifetime, and actual work in research for systems with increased reliability.

  7. Power Factor Improvement Using Automatic Power Factor Compensation (APFC) Device for Medical Industries in Malaysia

    OpenAIRE

    Zaidi Maryam Nabihah; Ali Adlan

    2018-01-01

    This paper present the project designed to correcting power factor for medical industries in Malaysia automatically. Which with hope to make the cost and energy usage efficient, because the energy source are depleting due to increase in population. Power factor is the ratio of real power and apparent power. This definition is mathematically represented as kW/kVA where kW is active power and kVA is apparent power (active + reactive). Reactive power is the non-working power generated by the mag...

  8. Performance and reliability of TPE-2 device with pulsed high power source

    International Nuclear Information System (INIS)

    Sato, Y.; Takeda, S.; Kiyama, S.

    1987-01-01

    The performance and the reliability of TPE-2 device with pulsed high power sources are described. To obtain the stable high beta plasma, the reproducibility and the reliability of the pulsed power sources must be maintained. A new power crowbar system with high efficiency and the switches with low jitter time are adopted to the bank system. A monitor system which always watches the operational states of the switches is developed too, and applied for the fast rising capacitor banks of TPE-2 device. The reliable operation for the bank has been realized, based on the data of switch monitor system

  9. Symmetric low-voltage powering system for relativistic electronic devices

    International Nuclear Information System (INIS)

    Agafonov, A.V.; Lebedev, A.N.; Krastelev, E.G.

    2005-01-01

    A special driver for double-sided powering of relativistic magnetrons and several methods of localized electron flow forming in the interaction region of relativistic magnetrons are proposed and discussed. Two experimental installations are presented and discussed. One of them is designed for laboratory research and demonstration experiments at a rather low voltage. The other one is a prototype of a full-scale installation for an experimental research at relativistic levels of voltages on the microwave generation in the new integrated system consisting of a relativistic magnetron and symmetrical induction driver

  10. Optimal location of shunt FACTS devices in a power system with high wind feeding

    Energy Technology Data Exchange (ETDEWEB)

    Shakib, Arefeh Danesh; Balzer, Gerd [Technische Univ. Darmstadt (Germany). Inst. of Electrical Power Systems

    2009-07-01

    Connections of large offshore wind farms, which will be placed in the North Sea, will lead to several problems in Germany's power system. One of these is the occurance of undervoltage at weak nodes due to the reduction of reactive power generation. This paper is covering several singular analyses of the system Jacobin matrix whose results are applied to identify sensors and weak places in power systems with high wind feeding. This allows for the solution of optimal location of shunt FACTS devices for example static var compensators (SVC) for voltage control. The optimizations are made on two parameters: the location of the devices and their sizes. Simulations are performed on a IEEE 57-bus system for several wind feeding scenarios. It can be shown that by use of optimal placed FACTS devices the voltage stability of the power system in the case of high wind feeding can be guaranteed. (orig.)

  11. Packaging Technologies for 500 C SiC Electronics and Sensors: Challenges in Material Science and Technology

    Science.gov (United States)

    Chen, Liang-Yu; Neudeck, Philip G.; Behelm, Glenn M.; Spry, David J.; Meredith, Roger D.; Hunter, Gary W.

    2015-01-01

    This paper presents ceramic substrates and thick-film metallization based packaging technologies in development for 500C silicon carbide (SiC) electronics and sensors. Prototype high temperature ceramic chip-level packages and printed circuit boards (PCBs) based on ceramic substrates of aluminum oxide (Al2O3) and aluminum nitride (AlN) have been designed and fabricated. These ceramic substrate-based chip-level packages with gold (Au) thick-film metallization have been electrically characterized at temperatures up to 550C. The 96 alumina packaging system composed of chip-level packages and PCBs has been successfully tested with high temperature SiC discrete transistor devices at 500C for over 10,000 hours. In addition to tests in a laboratory environment, a SiC junction field-effect-transistor (JFET) with a packaging system composed of a 96 alumina chip-level package and an alumina printed circuit board was tested on low earth orbit for eighteen months via a NASA International Space Station experiment. In addition to packaging systems for electronics, a spark-plug type sensor package based on this high temperature interconnection system for high temperature SiC capacitive pressure sensors was also developed and tested. In order to further significantly improve the performance of packaging system for higher packaging density, higher operation frequency, power rating, and even higher temperatures, some fundamental material challenges must be addressed. This presentation will discuss previous development and some of the challenges in material science (technology) to improve high temperature dielectrics for packaging applications.

  12. Research on Power Output Characteristics of Magnetic Core in Energy Harvesting Devices

    Directory of Open Access Journals (Sweden)

    Rong-Ping GUO

    2014-07-01

    Full Text Available Magnetic core is the dominant factor in the performance of current transformer energy harvesting devices. The power output model of the magnetic core is established and verified through experiments. According to the actual application requirements, the concept of power density is proposed. The relationships of power density to air gap, material and dimension of the magnetic core are analyzed and verified through experiments.

  13. A method and device allowing a more rational exploitation of electrical power-stations

    International Nuclear Information System (INIS)

    Mascarello, Jean.

    1974-01-01

    Description is given of a device permitting a more rational exploitation of electrical power-stations characterized by the fact that, while electric power available during slack hours is used for pressurizing air (the thus pressurized air being stored in tanks), the electric power available during slack days is used for generating hydrogen from water, said hydrogen being stored in other tanks, combustion of the stored hydrogen by the stored air being used for generating electric power during electric power consumption peak-periods [fr

  14. Usefulness of DC power flow for active power flow analysis with flow controlling devices

    NARCIS (Netherlands)

    Van Hertem, D.; Verboomen, J.; Purchala, K.; Belmans, R.; Kling, W.L.

    2006-01-01

    DC power flow is a commonly used tool for contingency analysis. Recently, due to its simplicity and robustness, it also becomes increasingly used for the real-time dispatch and techno-economic analysis of power systems. It is a simplification of a full power flow looking only at active power.

  15. Zinc injection method and device in nuclear power plant

    International Nuclear Information System (INIS)

    Maehara, Kazumi; Negishi, Itaru; Deguchi, Tatsuya; Ino, Takao; Sasaki, Noriyuki; Yotsuyanagi, Tadashi; Tobara, Hirotaka.

    1996-01-01

    The present invention concerns a method of injecting zinc into reactor water, and it can supply a solution of zinc at a high concentration by improving the solubility of zinc. Namely, zinc is used as a solute and is dissolved in an aqueous solution containing an electrolyte such as carbonic acid. The resultant zinc solution at a high concentration is injected to reactor water. In the device of the present invention, (1) a dissolution vessel for dissolving zinc comprises a zinc supply means at an upper portion thereof and a carbonic acid gas supply means at a lower portion, (2) an injection means supplies the solution in which zinc is dissolved at a high concentration to reactor water. An aqueous solution saturated with a carbonic acid gas is used as a solvent for dissolving zinc into reactor water at a high concentration. The dissolution vessel has a gas diffusion pipe at the bottom for introducing the carbonic acid gas and has a stirrer in the inside. Zinc is supplied continuously or discontinuously. Raw material zinc may be in the form of a plate, rod, granule, or powder, however, powdery zinc is preferably used. (I.S.)

  16. Extending the Limits of Wireless Power Transfer to Miniaturized Implantable Electronic Devices

    Directory of Open Access Journals (Sweden)

    Hugo Dinis

    2017-12-01

    Full Text Available Implantable electronic devices have been evolving at an astonishing pace, due to the development of fabrication techniques and consequent miniaturization, and a higher efficiency of sensors, actuators, processors and packaging. Implantable devices, with sensing, communication, actuation, and wireless power are of high demand, as they pave the way for new applications and therapies. Long-term and reliable powering of such devices has been a challenge since they were first introduced. This paper presents a review of representative state of the art implantable electronic devices, with wireless power capabilities, ranging from inductive coupling to ultrasounds. The different power transmission mechanisms are compared, to show that, without new methodologies, the power that can be safely transmitted to an implant is reaching its limit. Consequently, a new approach, capable of multiplying the available power inside a brain phantom for the same specific absorption rate (SAR value, is proposed. In this paper, a setup was implemented to quadruple the power available in the implant, without breaking the SAR limits. A brain phantom was used for concept verification, with both simulation and measurement data.

  17. A Novel Transdermal Power Transfer Device for the Application of Implantable Microsystems

    Directory of Open Access Journals (Sweden)

    Jing-Quan Liu

    2015-03-01

    Full Text Available This paper presents a transdermal power transfer device for the application of implantable devices or systems. The device mainly consists of plug and socket. The power transfer process can be started after inserting the plug into the socket with an applied potential on the plug. In order to improve the maneuverability and reliability of device during power transfer process, the metal net with mesh structure were added as a part of the socket to serve as intermediate electrical connection layer. The socket was encapsulated by polydimethylsiloxane (PDMS with good biocompatibility and flexibility. Two stainless steel hollow needles placed in the same plane acted as the insertion part of the needle plug, and Parylene C thin films were deposited on needles to serve as insulation layers. At last, the properties of the transdermal power transfer device were tested. The average contact resistance between needle and metal mesh was 0.454 Ω after 50 random insertions, which showed good electrical connection. After NiMH (nickel-metal hydride batteries were recharged for 10 min with current up to 200 mA, the caused resistive heat was less than 0.6 °C, which also demonstrated the low charging temperature and was suitable for charging implantable devices.

  18. Impedance matching wireless power transmission system for biomedical devices.

    Science.gov (United States)

    Lum, Kin Yun; Lindén, Maria; Tan, Tian Swee

    2015-01-01

    For medical application, the efficiency and transmission distance of the wireless power transfer (WPT) are always the main concern. Research has been showing that the impedance matching is one of the critical factors for dealing with the problem. However, there is not much work performed taking both the source and load sides into consideration. Both sides matching is crucial in achieving an optimum overall performance, and the present work proposes a circuit model analysis for design and implementation. The proposed technique was validated against experiment and software simulation. Result was showing an improvement in transmission distance up to 6 times, and efficiency at this transmission distance had been improved up to 7 times as compared to the impedance mismatch system. The system had demonstrated a near-constant transfer efficiency for an operating range of 2cm-12cm.

  19. Cleaning device for steam units in a nuclear power plant

    International Nuclear Information System (INIS)

    Sasamuro, Takemi.

    1978-01-01

    Purpose: To prevent radioactive contamination upon dismantling and inspection of steam units such as a turbine to a building containing such units and the peripheral area. Constitution: A steam generator indirectly heated by steam supplied from steam generating source in a separate system containing no radioactivity is provided to produce cleaning steam. A cleaning steam pipe is connected by way of a stop valve between separation valve of a nuclear power plant steam pipe and a high pressure turbine. Upon cleaning, the separation valve is closed, and steam supplied from the cleaning steam pipe is flown into a condenser. The water thus condensated is returned by way of a feed water heater and a condenser to a water storage tank. (Nakamura, S.)

  20. Using Piezoelectric Devices to Transmit Power through Walls

    Science.gov (United States)

    Sherrit, Stewart; Bar-Cohen, Yoseph; Bao, Xiaoqi

    2008-01-01

    A method denoted wireless acoustic-electric feed-through (WAEF) has been conceived for transmitting power and/or data signals through walls or other solid objects made of a variety of elastic materials that could be electrically conductive or nonconductive. WAEF would make it unnecessary to use wires, optical fibers, tubes, or other discrete wall-penetrating signal-transmitting components, thereby eliminating the potential for structural weakening or leakage at such penetrations. Avoidance of such penetrations could be essential in some applications in which maintenance of pressure, vacuum, or chemical or biological isolation is required. In a basic WAEF setup, a transmitting piezoelectric transducer on one side of a wall would be driven at resonance to excite ultrasonic vibrations in the wall. A receiving piezoelectric transducer on the opposite side of the wall would convert the vibrations back to an ultrasonic AC electric signal, which would then be detected and otherwise processed in a manner that would depend on the modulation (if any) applied to the signal and whether the signal was used to transmit power, data, or both. An electromechanical-network model has been derived as a computationally efficient means of analyzing and designing a WAEF system. This model is a variant of a prior model, known in the piezoelectric-transducer art as Mason's equivalent-circuit model, in which the electrical and mechanical dynamics, including electromechanical couplings, are expressed as electrical circuit elements that can include inductors, capacitors, and lumped-parameter complex impedances. The real parts of the complex impedances are used to account for dielectric, mechanical, and coupling losses in all components (including all piezoelectric-transducer, wall, and intermediate material layers). In an application to a three-layer piezoelectric structure, this model was shown to yield the same results as do solutions of the wave equations of piezoelectricity and acoustic

  1. Water releasing electric generating device for nuclear power plant

    International Nuclear Information System (INIS)

    Umehara, Toshihiro; Tomohara, Yasutaka; Usui, Yoshihiko.

    1994-01-01

    Warm sea water discharged after being used for cooling in an equipment of a coastal nuclear powder plant is discharged from a water discharge port to a water discharge pit, and a conduit vessel is disposed in front of the water discharge port for receiving overflown warm sea water. The warm sea water taken to the conduit vessel is converted to a fallen flow and charged to a turbine generator under water, and electric power is generated by the water head energy of the fallen flow before it is discharged to the water discharge pit. The conduit vessel incorporates a foam preventing unit having spiral flow channels therein, so that the warm sea water taken to the conduit vessel is flown into the water discharge pit after consuming the water head energy while partially branched and flown downwardly and gives lateral component to the downwarding flowing direction. Then, warm sea water is made calm when it is flown into the water discharge pit and, accordingly, generation of bubbles on the water surface of the water discharge pit is avoided. (N.H.)

  2. Reactor control device for controlling load of nuclear power plant

    International Nuclear Information System (INIS)

    Hirota, Tadakuni; Yokoyama, Terukuni; Masuda, Jiro.

    1981-01-01

    Purpose: To improve the load follow-up capacity of a nuclear reactor by automatically controlling the width of the not-sensing band of a control rod inserting and removing discriminator circuit. Constitution: When load control operations such as automatic load control, automatic frequency control, governor free operation and so forth are conducted, the width of a not sensing band of a control rod inserting and removing discriminator circuit is ao automatically controlled that the not sensing band width may return to ordinary value in a normal operation by avoiding the fast repetition of inserting and removing control rods by increasing the width of the insensing band if the period of a control deviation signal produced due to the variation in the load is quickly repeated and varied in correspondence to the control deviation signal. That is, a circuit for varying the insensing band of the control circuit for driving a control mechanism is provided to reduce the amount of driving the control rods in a load control operation and to reduce the strain of the power distribution of the nuclear reactor, thereby improving the load control capacity. (Yoshihara, H.)

  3. Diagnosis device for abnormality of power plant equipment

    International Nuclear Information System (INIS)

    Matono, Chiemi; Okamachi, Masao.

    1995-01-01

    In a power plant, if contained water leaks in a condensate system, water is automatically supplied from a feedwater system in accordance with the leakage. Since the diameter of the pipeline of the supplementary feedwater system is generally small, the influence of the leakage of the contained water appears remarkably as a change of the amount of the feed water in the supplementary feed water system. The change of the supplementary state of water to the condensate system by the supplementary feed water system is monitored, to estimate the presence or absence of the leakage of water contained in the condensate system depending on the result of the monitoring, and then the results are informed. In addition, when leakage of water contained in the condensate system is estimated, guidance information is prepared and outputted for coping with the result of the estimation, and the result of the estimation and the guidance information are displayed auditory and visually. As a result, a plant operator can recognize the abnormality of water leakage in the condensate system rapidly and accurately without observing various states of the condensate system and with no knowledge or experiences at high levels, thereby enabling to conduct appropriate processing rapidly. (N.H.)

  4. A novel electro-thermal model for wide bandgap semiconductor based devices

    DEFF Research Database (Denmark)

    Sintamarean, Nicolae Christian; Blaabjerg, Frede; Wang, Huai

    2013-01-01

    This paper propose a novel Electro-Thermal Model for the new generation of power electronics WBG-devices (by considering the SiC MOSFET-CMF20120D from CREE), which is able to estimate the device junction and case temperature. The Device-Model estimates the voltage drop and the switching energies...... by considering the device current, the off-state blocking voltage and junction temperature variation. Moreover, the proposed Thermal-Model is able to consider the thermal coupling within the MOSFET and its freewheeling diode, integrated into the same package, and the influence of the ambient temperature...... variation. The importance of temperature loop feedback in the estimation accuracy of device junction and case temperature is studied. Furthermore, the Safe Operating Area (SOA) of the SiC MOSFET is determined for 2L-VSI applications which are using sinusoidal PWM. Thus, by considering the heatsink thermal...

  5. Optimization Design of an Inductive Energy Harvesting Device for Wireless Power Supply System Overhead High-Voltage Power Lines

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2016-03-01

    Full Text Available Overhead high voltage power line (HVPL online monitoring equipment is playing an increasingly important role in smart grids, but the power supply is an obstacle to such systems’ stable and safe operation, so in this work a hybrid wireless power supply system, integrated with inductive energy harvesting and wireless power transmitting, is proposed. The energy harvesting device extracts energy from the HVPL and transfers that from the power line to monitoring equipment on transmission towers by transmitting and receiving coils, which are in a magnetically coupled resonant configuration. In this paper, the optimization design of online energy harvesting devices is analyzed emphatically by taking both HVPL insulation distance and wireless power supply efficiency into account. It is found that essential parameters contributing to more extracted energy include large core inner radius, core radial thickness, core height and small core gap within the threshold constraints. In addition, there is an optimal secondary coil turn that can maximize extracted energy when other parameters remain fixed. A simple and flexible control strategy is then introduced to limit power fluctuations caused by current variations. The optimization methods are finally verified experimentally.

  6. Power-Efficient Beacon Recognition Method Based on Periodic Wake-Up for Industrial Wireless Devices.

    Science.gov (United States)

    Song, Soonyong; Lee, Donghun; Jang, Ingook; Choi, Jinchul; Son, Youngsung

    2018-04-17

    Energy harvester-integrated wireless devices are attractive for generating semi-permanent power from wasted energy in industrial environments. The energy-harvesting wireless devices may have difficulty in their communication with access points due to insufficient power supply for beacon recognition during network initialization. In this manuscript, we propose a novel method of beacon recognition based on wake-up control to reduce instantaneous power consumption in the initialization procedure. The proposed method applies a moving window for the periodic wake-up of the wireless devices. For unsynchronized wireless devices, beacons are always located in the same positions within each beacon interval even though the starting offsets are unknown. Using these characteristics, the moving window checks the existence of the beacon associated withspecified resources in a beacon interval, checks again for neighboring resources at the next beacon interval, and so on. This method can reduce instantaneous power and generates a surplus of charging time. Thus, the proposed method alleviates the problems of power insufficiency in the network initialization. The feasibility of the proposed method is evaluated using computer simulations of power shortage in various energy-harvesting conditions.

  7. Economic feasibility of sail power devices on Great Lakes bulk carriers

    Energy Technology Data Exchange (ETDEWEB)

    1982-03-24

    Progress is reported in a project to determine whether retro-fitting existing Great Lakes bulk carriers with auxiliary sail powering devices is economically feasible. The approach being used is to apply known technology both in terms of sail devices and calculation methods to determine the amount of fuel that can be saved and the probable cost of the sail device. Progress includes the identification and collection of data needed to determine the state of the art as well as to model the problem. Several sail powering devices were compared and an unstayed cat rig was chosen for further analysis and its performance characteristics were incorporated into a computer model, which is flow charted. (LEW)

  8. Improvement of cosmic ray ruggedness of hybrid vehicles power semiconductor devices

    International Nuclear Information System (INIS)

    Nishida, Shuichi; Ohnishi, Toyokazu; Fujikawa, Touma; Nose, Noboru; Hamada, Kimimori; Shoji, Tomoyuki; Ishiko, Masayasu

    2010-01-01

    Power semiconductors which are used under high voltage conditions in HVs (Hybrid Vehicles) are required to have high destruction tolerance against cosmic rays as well as to meet conventional quality standards. In this paper, an SEB (Single Event Burnout) failure mechanism induced by cosmic rays in IGBTs (Insulated Gate Bipolar Transistors) was investigated. Through an optimized device design in which thyristor action was suppressed, the device destruction tolerance was greatly improved. (author)

  9. Filter and window assemblies for high power insertion device synchrotron radiation sources

    International Nuclear Information System (INIS)

    Khounsary, A.M.; Viccaro, P.J.; Kuzay, T.M.

    1992-01-01

    The powerful beams of x-ray radiation generated by insertion devices at high power synchrotron facilities deposit substantial amounts of localized heat in the front end and optical components that they intercept. X-ray beams from undulator sources, in particular, are confined to very narrow solid angles and therefore impose very high absorbed heat fluxes. This paper is devoted to a detailed study of the design of windows for the Advanced Photon Source undulators and wigglers, emphasizing alternative design concepts, material considerations, and cooling techniques necessary for handling the high heat load of the insertion devices. Various designs are thermally and structurally analyzed by numerically simulating full-power operating conditions. This analysis also has relevance to the design and development of other beam line components which are subjected to the high heat loads of insertion devices

  10. Acousto-electric transport in MgO/ZnO-covered graphene on SiC

    Science.gov (United States)

    Liou, Y.-T.; Hernández-Mínguez, A.; Herfort, J.; Lopes, J. M. J.; Tahraoui, A.; Santos, P. V.

    2017-11-01

    We investigate the acousto-electric transport induced by surface acoustic waves (SAWs) in epitaxial graphene (EG) coated by a MgO/ZnO film. The deposition of a thin MgO layer protects the EG during the sputtering of a piezoelectric ZnO film for the efficient generation of SAWs. We demonstrate by Raman and electric measurements that the coating does not harm the EG structural and electronic properties. We report the generation of two SAW modes with frequencies around 2 GHz. For both modes, we measure acousto-electric currents in EG devices placed in the SAW propagation path. The currents increase linearly with the SAW power, reaching values up to almost two orders of magnitude higher than in previous reports for acousto-electric transport in EG on SiC. Our results agree with the predictions from the classical relaxation model of the interaction between SAWs and a two dimensional electron gas.

  11. Electro-thermal Modeling of Modern Power Devices for Studying Abnormal Operating Conditions

    DEFF Research Database (Denmark)

    Wu, Rui

    in industrial power electronic systems in the range above 10 kW. The failure of IGBTs can be generally classified as catastrophic failures and wear out failures. A wear out failure is mainly induced by accumulated degradation with time, while a catastrophic failure is triggered by a single-event abnormal....... The objective of this project has been to model and predict the electro-thermal behavior of IGBT power modules under abnormal conditions, especially short circuits. A thorough investigation on catastrophic failure modes and mechanisms of modern power semiconductor devices, including IGBTs and power diodes, has...

  12. Emerging technologies to power next generation mobile electronic devices using solar energy

    Institute of Scientific and Technical Information of China (English)

    Dewei JIA; Yubo DUAN; Jing LIU

    2009-01-01

    Mobile electronic devices such as MP3, mobile phones, and wearable or implanted medical devices have already or will soon become a necessity in peoples' lives.However, the further development of these devices is restricted not only by the inconvenient charging process of the power module, but also by the soaring prices of fossil fuel and its downstream chain of electricity manipulation.In view of the huge amount of solar energy fueling the world biochemically and thermally, a carry-on electricity harvester embedded in portable devices is emerging as a most noteworthy research area and engineering practice for a cost efficient solution. Such a parasitic problem is intrinsic in the next generation portable devices. This paper is dedicated to presenting an overview of the photovoltaic strategy in the chain as a reference for researchers and practitioners committed to solving the problem.

  13. [An implantable micro-device using wireless power transmission for measuring aortic aneurysm sac pressure].

    Science.gov (United States)

    Guo, Xudong; Ge, Bin; Wang, Wenxing

    2013-08-01

    In order to detect endoleaks after endovascular aneurysm repair (EVAR), we developed an implantable micro-device based on wireless power transmission to measure aortic aneurysm sac pressure. The implantable micro-device is composed of a miniature wireless pressure sensor, an energy transmitting coil, a data recorder and a data processing platform. Power transmission without interconnecting wires is performed by a transmitting coil and a receiving coil. The coupling efficiency of wireless power transmission depends on the coupling coefficient between the transmitting coil and the receiving coil. With theoretical analysis and experimental study, we optimized the geometry of the receiving coil to increase the coupling coefficient. In order to keep efficiency balance and satisfy the maximizing conditions, we designed a closed loop power transmission circuit, including a receiving voltage feedback module based on wireless communication. The closed loop improved the stability and reliability of transmission energy. The prototype of the micro-device has been developed and the experiment has been performed. The experiments showed that the micro-device was feasible and valid. For normal operation, the distance between the transmitting coil and the receiving coil is smaller than 8cm. Besides, the distance between the micro-device and the data recorder is within 50cm.

  14. A nondestructive testing device for determining 235U enrichment in power reactor fuel elements

    International Nuclear Information System (INIS)

    Liu Lanhua; Liu Nangai

    1990-07-01

    The development and application of a nondestructive testing device are presented, which is used for determining the 235 U enrichment in the mixed fuel of fuel elements with UO 2 pellets. The testing efficiency is improved because the passive gamma ray method and a hole-bored NaI crystal and four channel multichannel analyzer are used. The false discrimination rate is reduced as the average comparing method is taken. This device is simple in structure and easy in operation. It has provided a new testing tool for the fuel elements production in China. This device has successfully been used in Qinshan Nuclear Power Plant in testing its fuel elements

  15. High-power waveguide resonator second harmonic device with external conversion efficiency up to 75%

    Science.gov (United States)

    Stefszky, M.; Ricken, R.; Eigner, C.; Quiring, V.; Herrmann, H.; Silberhorn, C.

    2018-06-01

    We report on a highly efficient waveguide resonator device for the production of 775 nm light using a titanium indiffused LiNbO3 waveguide resonator. When scanning the resonance, the device produces up to 110 mW of second harmonic power with 140 mW incident on the device—an external conversion efficiency of 75%. The cavity length is also locked, using a Pound–Drever–Hall type locking scheme, involving feedback to either the cavity temperature or the laser frequency. With laser frequency feedback, a stable output power of approximately 28 mW from a 52 mW pump is seen over one hour.

  16. Observation of theoretical power saturation by the KHI free electron laser device

    International Nuclear Information System (INIS)

    Oda, Fumihiko; Yokoyama, Minoru; Kawai, Masayuki; Miura, Hidenori; Koike, Hidehito; Sobajima, Masaaki; Nomaru, Keiji; Kuroda, Haruo

    2002-01-01

    The saturation of free electron laser (FEL) output power by the KHI-FEL device was achieved on 3rd, October 2000 at the wavelength of 9.3 μm. The FEL device has operated thereafter successfully in the wavelength region between 4.0 and 16.0 μm. The macropulse average FEL power of 37.5 kW, which is the theoretical saturation level, has been obtained at the wavelength of 7.9 μm. The net FEL gain was estimated to be 16%. (author)

  17. Organization of synchronization of power supplies for the T-15 device injector

    International Nuclear Information System (INIS)

    Gerasimov, V.P.; Gordin, V.I.; Grachev, V.F.; Ishkin, V.A.; Mozin, I.V.; Kuz'min, B.N.; Skosarev, V.A.

    1984-01-01

    The description of the system for the T-15 tokamak power supply and injector synchronization is presented. The synchronization system consists of 3 branches, comprising 6 sychronization devices according to the number of ion sources. According to the character of control, structurally and territorially, each branch of the synchronization system is devided into three parts: program-controlled, relized in CAMAC standard, synchronization devices, located in the room of low-voltage power supply system, and control channels, manufactured in the form of optical communication channels with controls units or galvanic decoupling units

  18. Simulation of push-pull inverter using wide bandgap devices

    Science.gov (United States)

    Al-badri, Mustafa; Matin, Mohammed A.

    2016-09-01

    This paper discusses the use of wide bandgap devices (SiC-MOSFET) in the design of a push-pull inverter which provides inexpensive low power dc-ac inverters. The parameters used were 1200V SiC MOSFET(C2M0040120D) made by power company ROHM. This modeling was created using parameters that were provided from a device datasheet. The spice model is provided by this company to study the effect of adding this component on push-pull inverter ordinary circuit and compared results between SiC MOSFET and silicon MOSFET (IRFP260M). The results focused on Vout and Vmos stability as well as on output power and MOSFET power loss because it is a very crucial aspect on DC-AC inverter design. These results are done using the National Instrument simulation program (Multisim 14). It was found that power loss is better in the 12 and 15 vdc inverter. The Vout in the SIC MOSFET circuit shows more stability in the high current low resistance load in comparison to the Silicon MOSFET circuit and this will improve the overall performance of the circuit.

  19. Harvesting energy an sustainable power source, replace batteries for powering WSN and devices on the IoT

    Science.gov (United States)

    Pop-Vadean, A.; Pop, P. P.; Latinovic, T.; Barz, C.; Lung, C.

    2017-05-01

    Harvesting energy from nonconventional sources in the environment has received increased attention over the past decade from researchers who study these alternative energy sources for low power applications. Although that energy harvested is small and in the order of milliwatt, it can provide enough power for wireless sensors and other low-power applications. In the environment there is a lot of wasted energy that can be converted into electricity to power the various circuits and represents a potentially cheap source of power. Energy harvesting is important because it offers an alternative power supply for electronic devices where is does not exist conventional energy sources. This technology applied in a wireless sensor network (WSN) and devices on the IoT, will eliminate the need for network-based energy and conventional batteries, will minimize maintenance costs, eliminate cables and batteries and is ecological. It has the same advantage in applications from remote locations, underwater, and other hard to reach places where conventional batteries and energy are not suitable. Energy harvesting will promote environmentally friendly technologies that will save energy, will reduce CO2 emissions, which makes this technology indispensable for achieving next-generation smart cities and sustainable society. In response to the challenges of energy, in this article we remind the basics of harvesting energy and we discuss the various applications of this technology where traditional batteries cannot be used.

  20. A microfabricated low cost enzyme-free glucose fuel cell for powering low-power implantable devices

    Science.gov (United States)

    Oncescu, Vlad; Erickson, David

    In the past decade the scientific community has showed considerable interest in the development of implantable medical devices such as muscle stimulators, neuroprosthetic devices, and biosensors. Those devices have low power requirements and can potentially be operated through fuel cells using reactants present in the body such as glucose and oxygen instead of non-rechargeable lithium batteries. In this paper, we present a thin, enzyme-free fuel cell with high current density and good stability at a current density of 10 μA cm -2. A non-enzymatic approach is preferred because of higher long term stability. The fuel cell uses a stacked electrode design in order to achieve glucose and oxygen separation. An important characteristic of the fuel cell is that it has no membrane separating the electrodes, which results in low ohmic losses and small fuel cell volume. In addition, it uses a porous carbon paper support for the anodic catalyst layer which reduces the amount of platinum or other noble metal catalysts required for fabricating high surface area electrodes with good reactivity. The peak power output of the fuel cell is approximately 2 μW cm -2 and has a sustainable power density of 1.5 μW cm -2 at 10 μA cm -2. An analysis on the effects of electrode thickness and inter electrode gap on the maximum power output of the fuel cell is also performed.

  1. Integrated Production of Ultra-Low Defect GaN Films and Devices for High-Power Amplifiers, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — High quality GaN epitaxial films are key to current efforts for development of both high-power/high-speed electronic devices and optoelectronic devices. In fact,...

  2. Integrated Production of Ultra-Low Defect GaN Films and Devices for High-Power Amplifiers, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — High quality GaN epitaxial films are one of the keys to current efforts for development of both high-power/high-speed electronic devices and optoelectronic devices....

  3. Synthesis of whiskers of SiC microwave assisted; Sintesis de whiskers de SiC asistida por microondas

    Energy Technology Data Exchange (ETDEWEB)

    Garza-Mendez, F. J.; Vanegas, A. J.; Vazquez, B. A.; Garza-Paz, J.

    2013-06-01

    We developed a new process for the synthesis of SiC whiskers assisted by microwaves; this is based on the mixture of silica xerogels and graphite powder. As energy source were used microwaves of 2.45 GHz and 1.0 kW of power RMS. On the other hand, mesoporous silica was synthesized via sol-gel, the precursors used were TEOS/H{sub 2}O and ethanol. Through analysis of the BET is determined the value of average pore size (3.0 nm) and the surface area (1090 m2/g).By mean of X-Ray diffraction it was demonstrated that the silica obtained is an amorphous solid and, the powders obtained in the microwave synthesis are {beta}-SiC. Synthesized SiC powders were observed using a SEM in secondary electron mode, it was observed that this powders consists of SiC whiskers. The effect of microwaves on the synthesis of whiskers of SiC is discussed in the present work. (Author) 19 refs.

  4. A broadband high-efficiency Doherty power amplifier using symmetrical devices

    Science.gov (United States)

    Cheng, Zhiqun; Zhang, Ming; Li, Jiangzhou; Liu, Guohua

    2018-04-01

    This paper proposes a method for broadband and high-efficiency amplification of Doherty power amplifier (DPA) using symmetric devices. In order to achieve the perfect load modulation, the carrier amplifier output circuit total power length is designed to odd multiple of 90°, and the peak amplifier output total power length is designed to even multiple of 180°. The proposed method is demonstrated by designing a broadband high-efficiency DPA using identical 10-W packaged GaN HEMT devices. Measurement results show that over 51% drain efficiency is achieved at 6-dB back-off power, over the frequency band of 1.9–2.4 GHz. Project supported by the National Natural Science Foundation of China (No. 60123456), the Zhejiang Provincial Natural Science Foundation of China (No. LZ16F010001), and the Zhejiang Provincial Public Technology Research Project (No. 2016C31070).

  5. Processing and characterization of device solder interconnection and module attachment for power electronics modules

    Science.gov (United States)

    Haque, Shatil

    This research is focused on the processing of an innovative three-dimensional packaging architecture for power electronics building blocks with soldered device interconnections and subsequent characterization of the module's critical interfaces. A low-cost approach termed metal posts interconnected parallel plate structure (MPIPPS) was developed for packaging high-performance modules of power electronics building blocks (PEBB). The new concept implemented direct bonding of copper posts, not wire bonding of fine aluminum wires, to interconnect power devices as well as joining the different circuit planes together. We have demonstrated the feasibility of this packaging approach by constructing PEBB modules (consisting of Insulated Gate Bipolar Transistors (IGBTs), diodes, and a few gate driver elements and passive components). In the 1st phase of module fabrication with IGBTs with Si3N 4 passivation, we had successfully fabricated packaged devices and modules using the MPIPPS technique. These modules were tested electrically and thermally, and they operated at pulse-switch and high power stages up to 6kW. However, in the 2nd phase of module fabrication with polyimide passivated devices, we experienced significant yield problems due to metallization difficulties of these devices. The under-bump metallurgy scheme for the development of a solderable interface involved sputtering of Ti-Ni-Cu and Cr-Cu, and an electroless deposition of Zn-Ni-Au metallization. The metallization process produced excellent yield in the case of Si3N4 passivated devices. However, under the same metallization schemes, devices with a polyimide passivation exhibited inconsistent electrical contact resistance. We found that organic contaminants such as hydrocarbons remain in the form of thin monolayers on the surface, even in the case of as-received devices from the manufacturer. Moreover, in the case of polyimide passivated devices, plasma cleaning introduced a few carbon constituents on the

  6. Transmission line pulse system for avalanche characterization of high power semiconductor devices

    Science.gov (United States)

    Riccio, Michele; Ascione, Giovanni; De Falco, Giuseppe; Maresca, Luca; De Laurentis, Martina; Irace, Andrea; Breglio, Giovanni

    2013-05-01

    Because of the increasing in power density of electronic devices for medium and high power application, reliabilty of these devices is of great interest. Understanding the avalanche behaviour of a power device has become very important in these last years because it gives an indication of the maximum energy ratings which can be seen as an index of the device ruggedness. A good description of this behaviour is given by the static IV blocking characteristc. In order to avoid self heating, very relevant in high power devices, very short pulses of current have to be used, whose value can change from few milliamps up to tens of amps. The most used method to generate short pulses is the TLP (Transmission Line Pulse) test, which is based on charging the equivalent capacitance of a transmission line to high value of voltage and subsequently discharging it onto a load. This circuit let to obtain very short square pulses but it is mostly used for evaluate the ESD capability of semiconductor and, in this environment, it generates pulses of low amplitude which are not high enough to characterize the avalanche behaviour of high power devices . Advanced TLP circuit able to generate high current are usually very expensive and often suffer of distorption of the output pulse. In this article is proposed a simple, low cost circuit, based on a boosted-TLP configuration, which is capable to produce very square pulses of about one hundreds of nanosecond with amplitude up to some tens of amps. A prototype is implemented which can produce pulses up to 20A of amplitude with 200 ns of duration which can characterize power devices up to 1600V of breakdown voltage. Usage of microcontroller based logic make the circuit very flexible. Results of SPICE simulation are provided, together with experimental results. To prove the effectiveness of the circuit, the I-V blocking characteristics of two commercial devices, namely a 600V PowerMOS and a 1200V Trench-IGBT, are measured at different

  7. Behaviors of SiC fibers at high temperature

    International Nuclear Information System (INIS)

    Colin, C.; Falanga, V.; Gelebart, L.

    2010-01-01

    On the one hand, considering the improvements of mechanical and thermal behaviours of the last generation of SiC fibers (Hi-Nicalon S, Tyranno SA3); on the other hand, regarding physical and chemical properties and stability under irradiation, SiC/SiC composites are potential candidates for nuclear applications in advanced fission and fusion reactors. CEA must characterize and optimize these composites before their uses in reactors. In order to study this material, CEA is developing a multi-scale approach by modelling from fibers to bulk composite specimen: fibres behaviours must be well known in first. Thus, CEA developed a specific tensile test device on single fibers at high temperature, named MecaSiC. Using this device, we have already characterized the thermoelastic and thermoelectric behaviours of SiC fibers. Additional results about the plastic properties at high temperatures were also obtained. Indeed, we performed tensile tests between 1200 degrees C up to 1700 degrees C to characterize this plastic behaviour. Some thermal annealing, up to 3 hours at 1700 degrees C, had been also performed. Furthermore, we compare the mechanical behaviours with the thermal evolution of the electric resistivity of these SiC fibers. Soon, MecaSiC will be coupled to a new charged particle accelerator. Thus, in this configuration, we will be able to study in-situ irradiation effects on fibre behaviours, as swelling or creep for example

  8. Pd/CeO2/SiC Chemical Sensors

    Science.gov (United States)

    Lu, Weijie; Collins, W. Eugene

    2005-01-01

    The incorporation of nanostructured interfacial layers of CeO2 has been proposed to enhance the performances of Pd/SiC Schottky diodes used to sense hydrogen and hydrocarbons at high temperatures. If successful, this development could prove beneficial in numerous applications in which there are requirements to sense hydrogen and hydrocarbons at high temperatures: examples include monitoring of exhaust gases from engines and detecting fires. Sensitivity and thermal stability are major considerations affecting the development of high-temperature chemical sensors. In the case of a metal/SiC Schottky diode for a number of metals, the SiC becomes more chemically active in the presence of the thin metal film on the SiC surface at high temperature. This increase in chemical reactivity causes changes in chemical composition and structure of the metal/SiC interface. The practical effect of the changes is to alter the electronic and other properties of the device in such a manner as to degrade its performance as a chemical sensor. To delay or prevent these changes, it is necessary to limit operation to a temperature sensor structures. The present proposal to incorporate interfacial CeO2 films is based partly on the observation that nanostructured materials in general have potentially useful electrical properties, including an ability to enhance the transfer of electrons. In particular, nanostructured CeO2, that is CeO2 with nanosized grains, has shown promise for incorporation into hightemperature electronic devices. Nanostructured CeO2 films can be formed on SiC and have been shown to exhibit high thermal stability on SiC, characterized by the ability to withstand temperatures somewhat greater than 700 C for limited times. The exchanges of oxygen between CeO2 and SiC prevent the formation of carbon and other chemical species that are unfavorable for operation of a SiC-based Schottky diode as a chemical sensor. Consequently, it is anticipated that in a Pd/CeO2/SiC Schottky

  9. A wireless power transmission system for implantable devices in freely moving rodents.

    Science.gov (United States)

    Eom, Kyungsik; Jeong, Joonsoo; Lee, Tae Hyung; Kim, Jinhyung; Kim, Junghoon; Lee, Sung Eun; Kim, Sung June

    2014-08-01

    Reliable wireless power delivery for implantable devices in animals is highly desired for safe and effective experimental use. Batteries require frequent replacement; wired connections are inconvenient and unsafe, and short-distance inductive coupling requires the attachment of an exterior transmitter to the animal's body. In this article, we propose a solution by which animals with implantable devices can move freely without attachments. Power is transmitted using coils attached to the animal's cage and is received by a receiver coil implanted in the animal. For a three-dimensionally uniform delivery of power, we designed a columnar dual-transmitter coil configuration. A resonator-based inductive link was adopted for efficient long-range power delivery, and we used a novel biocompatible liquid crystal polymer substrate as the implantable receiver device. Using this wireless power delivery system, we obtain an average power transfer efficiency of 15.2% (minimum efficiency of 10% and a standard deviation of 2.6) within a cage of 15×20×15 cm3.

  10. Micro/Nano Fabricated Solid-State Thermoelectric Generator Devices for Integrated High Voltage Power Sources

    Science.gov (United States)

    Fleurial, J.-P.; Ryan, M. A.; Snyder, G. J.; Huang, C.-K.; Whitacre, J. F.; Patel, J.; Lim, J.; Borshchevsky, A.

    2002-01-01

    Deep space missions have a strong need for compact, high power density, reliable and long life electrical power generation and storage under extreme temperature conditions. Except for electrochemical batteries and solar cells, there are currently no available miniaturized power sources. Conventional power generators devices become inefficient in extreme environments (such as encountered in Mars, Venus or outer planet missions) and rechargeable energy storage devices can only be operated in a narrow temperature range thereby limiting mission duration. The planned development of much smaller spacecrafts incorporating a variety of micro/nanodevices and miniature vehicles will require novel, reliable power technologies. It is also expected that such micro power sources could have a wide range of terrestrial applications, in particular when the limited lifetime and environmental limitations of batteries are key factors. Advanced solid-state thermoelectric combined with radioisotope or waste heat sources and low profile energy storage devices are ideally suited for these applications. The Jet Propulsion Laboratory has been actively pursuing the development of thermoelectric micro/nanodevices that can be fabricated using a combination of electrochemical deposition and integrated circuit processing techniques. Some of the technical challenges associated with these micro/nanodevice concepts, their expected level of performance and experimental fabrication and testing results to date are presented and discussed.

  11. Implementation of heat production and storage technology and devices in power systems

    International Nuclear Information System (INIS)

    Romanovsky, G.; Mutale, J.

    2012-01-01

    Implementation of heat storage devices and technologies at power generation plants is a promising way to provide more efficient use of natural energy resources. Heat storage devices can partly replace conventional heating technologies (such as direct use of fossil fuels) during peak energy demand or in the situations where heat and electricity supply and demand do not coincide and to obtain low cost heat energy which can be further transmitted to industrial, commercial and domestic consumers. This paper presents the innovative Heat Production and Storage Device and its application at conventional, nuclear and renewable power generation plants for optimization and balancing of electricity grids. The Heat Production and Storage Device is a vessel type induction-immersion heat production and storage device which produces pre-heated water under pressure for heat energy conservation. Operation of this device is based on simultaneous and/or sequential action of an inductor and an immersion heater and can be easily connected to the electricity network as a single or a three phase unit. Heat energy accumulated by the Heat Production and Storage Device can be utilized in different industrial technological processes during periods of high energy prices. - Highlights: ► Heat Production and Storage Device for energy conservation within low load hours. ► Simultaneous and/or sequential operation of the inductor and immersion heater. ► Transform the energy of low frequency electrical current (50 Hz) into heat energy. ► Connection to the electricity network either in single or three phase unit. ► Heat Production and Storage Device will enhance the economic value of the system.

  12. Adaptive Transcutaneous Power Transfer to Implantable Devices: A State of the Art Review.

    Science.gov (United States)

    Bocan, Kara N; Sejdić, Ervin

    2016-03-18

    Wireless energy transfer is a broad research area that has recently become applicable to implantable medical devices. Wireless powering of and communication with implanted devices is possible through wireless transcutaneous energy transfer. However, designing wireless transcutaneous systems is complicated due to the variability of the environment. The focus of this review is on strategies to sense and adapt to environmental variations in wireless transcutaneous systems. Adaptive systems provide the ability to maintain performance in the face of both unpredictability (variation from expected parameters) and variability (changes over time). Current strategies in adaptive (or tunable) systems include sensing relevant metrics to evaluate the function of the system in its environment and adjusting control parameters according to sensed values through the use of tunable components. Some challenges of applying adaptive designs to implantable devices are challenges common to all implantable devices, including size and power reduction on the implant, efficiency of power transfer and safety related to energy absorption in tissue. Challenges specifically associated with adaptation include choosing relevant and accessible parameters to sense and adjust, minimizing the tuning time and complexity of control, utilizing feedback from the implanted device and coordinating adaptation at the transmitter and receiver.

  13. A new automatic design method to develop multilayer thin film devices for high power laser applications

    International Nuclear Information System (INIS)

    Sahoo, N.K.; Apparao, K.V.S.R.

    1992-01-01

    Optical thin film devices play a major role in many areas of frontier technology like development of various laser systems to the designing of complex and precision optical systems. Design and development of these devices are really challenging when they are meant for high power laser applications. In these cases besides desired optical characteristics, the devices are expected to satisfy a whole range of different needs like high damage threshold, durability etc. In the present work a novel completely automatic design method based on Modified Complex Method has been developed for designing of high power thin film devices. Unlike most of the other methods it does not need any suitable starting design. A quarterwave design is sufficient to start with. If required, it is capable of generating its own starting design. The computer code of the method is very simple to implement. This report discusses this novel automatic design method and presents various practicable output designs generated by it. The relative efficiency of the method along with other powerful methods has been presented while designing a broadband IR antireflection coating. The method is also incorporated with 2D and 3D electric field analysis programmes to produce high damage threshold designs. Some experimental devices developed using such designs are also presented in the report. (author). 36 refs., 41 figs

  14. Adaptive Transcutaneous Power Transfer to Implantable Devices: A State of the Art Review

    Directory of Open Access Journals (Sweden)

    Kara N. Bocan

    2016-03-01

    Full Text Available Wireless energy transfer is a broad research area that has recently become applicable to implantable medical devices. Wireless powering of and communication with implanted devices is possible through wireless transcutaneous energy transfer. However, designing wireless transcutaneous systems is complicated due to the variability of the environment. The focus of this review is on strategies to sense and adapt to environmental variations in wireless transcutaneous systems. Adaptive systems provide the ability to maintain performance in the face of both unpredictability (variation from expected parameters and variability (changes over time. Current strategies in adaptive (or tunable systems include sensing relevant metrics to evaluate the function of the system in its environment and adjusting control parameters according to sensed values through the use of tunable components. Some challenges of applying adaptive designs to implantable devices are challenges common to all implantable devices, including size and power reduction on the implant, efficiency of power transfer and safety related to energy absorption in tissue. Challenges specifically associated with adaptation include choosing relevant and accessible parameters to sense and adjust, minimizing the tuning time and complexity of control, utilizing feedback from the implanted device and coordinating adaptation at the transmitter and receiver.

  15. Near field resonant inductive coupling to power electronic devices dispersed in water

    NARCIS (Netherlands)

    Kuipers, J.; Bruning, H.; Bakker, S.; Rijnaarts, H.H.M.

    2012-01-01

    The purpose of this research was to investigate inductive coupling as a way to wirelessly power electronic devices dispersed in water. The most important parameters determining this efficiency are: (1) the coupling between transmitting and receiving coils, (2) the quality factors of the transmitting

  16. Mechanization devices for maintenance of technological components of nuclear power plant primary circuit

    International Nuclear Information System (INIS)

    Palicka, L.; Blazek, J.

    1987-01-01

    Selected mechanization devices are described, developed for assembly and repair jobs and for decontamination of the steam generator, the main closing valve and the main circulating pump of a WWER-440 nuclear power plant. (author). 8 figs., 3 tabs., 10 refs

  17. Rotary powered device for bone marrow aspiration and biopsy yields excellent specimens quickly and efficiently.

    Science.gov (United States)

    Swords, Ronan T; Kelly, Kevin R; Cohen, Stephen C; Miller, Larry J; Philbeck, Thomas E; Hacker, Sander O; Spadaccini, Cathy J; Giles, Francis J; Brenner, Andrew J

    2010-06-01

    Recently, a new FDA-cleared battery powered bone marrow biopsy system was developed to allow operators access to the bone marrow space quickly and efficiently. A pre-clinical evaluation of the device (OnControl, Vidacare Corporation, San Antonio, TX, USA) on anesthetized pigs was conducted, in addition to a clinical evaluation in hematology clinic patients requiring a bone marrow biopsy. Twenty-six samples were collected from the swine model. No cellular artifact or thermal damage was reported in any of the samples obtained. For the clinical evaluation of the device, 16 patients were recruited. Mean time from needle contact with skin to needle removal was 38.5 +/- 13.94 seconds. No complications were reported. In this study, the manual and powered samples were equivalent in specimen quality. In the patients evaluated, the device was safe, easy to use and the mean procedural time was significantly faster than previously reported with a manual technique.

  18. Strainer device for an emergency cooling system in a nuclear power plant

    International Nuclear Information System (INIS)

    Trybom, J.

    1997-01-01

    The invention relates to a strainer device for separating contaminants from water in an emergency cooling system for a nuclear power plant. The nuclear power plant has a wet-well for water in the emergency cooling system and the strainer device comprises at least one strainer device, which is arranged in the wet-well. According to the invention the strainer is suspended in a desired position in the wet-well by means of at least a group of at least three tie rods arranged at angles to each other, each tie rod being fixed at one end to the strainer and its other end to the container or an anchor ring joined thereto. (author) figs

  19. Power cycling test of a 650 V discrete GaN-on-Si power device with a laminated packaging embedding technology

    DEFF Research Database (Denmark)

    Song, Sungyoung; Munk-Nielsen, Stig; Uhrenfeldt, Christian

    2017-01-01

    A GaN-on-Si power device is a strong candidate to replace power components based on silicon in high-end market for low-voltage applications, thanks to its electrical characteristics. To maximize opportunities of the GaN device in field applications, a package technology plays an important role...... in a discrete GaN power device. A few specialized package technologies having very lower stray inductance and higher thermal conductivity have been proposed for discrete GaN-on-Si power devices. Despite their superior performance, there has been little discussion of their reliability. The paper presents a power...... cycling test of a discrete GaN power device employing a laminated embedded packaging technology subjected to 125 degrees Celsius junction temperature swing. Failure modes are described with collected electrical characteristics and measured temperature data under the test. In conclusion, physical...

  20. Open loop control of filament heating power supply for large volume plasma device

    Energy Technology Data Exchange (ETDEWEB)

    Sugandhi, R., E-mail: ritesh@ipr.res.in [Institute for Plasma Research, Gandhinagar, Gujarat 382428 (India); Homi Bhabha National Institute, Mumbai 400094 (India); Srivastava, P.K.; Sanyasi, A.K. [Homi Bhabha National Institute, Mumbai 400094 (India); Srivastav, Prabhakar [Institute for Plasma Research, Gandhinagar, Gujarat 382428 (India); Homi Bhabha National Institute, Mumbai 400094 (India); Awasthi, L.M., E-mail: kushagra.lalit@gmail.com [Institute for Plasma Research, Gandhinagar, Gujarat 382428 (India); Homi Bhabha National Institute, Mumbai 400094 (India); Mattoo, S.K. [Homi Bhabha National Institute, Mumbai 400094 (India)

    2017-02-15

    A power supply (20 V, 10 kA) for powering the filamentary cathode has been procured, interfaced and integrated with the centralized control system of Large Volume Plasma Device (LVPD). Software interface has been developed on the standard Modbus RTU communication protocol. It facilitates the dashboard for configuration, on line status monitoring, alarm management, data acquisition, synchronization and controls. It has been tested for stable operation of the power supply for the operational capabilities. The paper highlights the motivation, interface description, implementation and results obtained.

  1. Overview of FACTS devices for wind power plants directly connected to the transmission network

    DEFF Research Database (Denmark)

    Adamczyk, Andrzej Grzegorz; Teodorescu, Remus; Rodriguez, Pedro

    2010-01-01

    Growing number of wind turbines is changing electricity generation profile all over the world. This brings challenges for power system operation, which was designed and developed around conventional power plants with directly coupled synchronous generators. In result, safety and stability...... of the electrical network with high wind energy penetration might be compromised. For this reason transmission system operators (TSO) impose more stringent connection requirements on the wind power plant (WPP) owners. On the other hand flexible AC transmission systems (FACTS) devices offer enhancement of grid...... research in FACTS applicability for WPPs is summarized. Examples of few existing FACTS applications for wind farms are given....

  2. Open loop control of filament heating power supply for large volume plasma device

    International Nuclear Information System (INIS)

    Sugandhi, R.; Srivastava, P.K.; Sanyasi, A.K.; Srivastav, Prabhakar; Awasthi, L.M.; Mattoo, S.K.

    2017-01-01

    A power supply (20 V, 10 kA) for powering the filamentary cathode has been procured, interfaced and integrated with the centralized control system of Large Volume Plasma Device (LVPD). Software interface has been developed on the standard Modbus RTU communication protocol. It facilitates the dashboard for configuration, on line status monitoring, alarm management, data acquisition, synchronization and controls. It has been tested for stable operation of the power supply for the operational capabilities. The paper highlights the motivation, interface description, implementation and results obtained.

  3. Effects of Power Tracking Algorithms on Lifetime of Power Electronic Devices Used in Solar Systems

    Directory of Open Access Journals (Sweden)

    Canras Batunlu

    2016-10-01

    Full Text Available In photovoltaic solar energy systems, power management algorithms (PMAs, usually called maximum power point tracking (MPPT algorithms, are widely used for extracting maximum available power at every point in time. However, tracking the maximum power has negative effects on the availability of solar energy systems. This is due, mainly, to the created disturbances and thermal stresses on the associated power electronic converters (PECs. This work investigates the effects of PMA on the lifetime consumption, thermal stresses and failures on DC-DC converters used in solar systems. Firstly theoretical analysis and modelling of photovoltaic solar systems including converter’s electro thermal characteristics were developed. Subsequently, experiments on photovoltaic solar systems were carried out using two different PMAs, namely, perturb and observe (P&O and incremental conductance (IC. Real-time data was collected, under different operating conditions, including thermal behavior using thermal imaging camera and dSPACE. Converters’ thermal cycling was found to be approximately 3 °C higher with the IC algorithm. The steady state temperature was 52.7 °C, for the IC while it was 42.6 °C for P&O. Although IC algorithm offers more accurate power management tool, it causes more severe thermal stresses which, in this study, has led to approximately 1.4 times greater life consumption compared to P&O.

  4. Triggering Mechanism for Neutron Induced Single-Event Burnout in Power Devices

    Science.gov (United States)

    Shoji, Tomoyuki; Nishida, Shuichi; Hamada, Kimimori

    2013-04-01

    Cosmic ray neutrons can trigger catastrophic failures in power devices. It has been reported that parasitic transistor action causes single-event burnout (SEB) in power metal-oxide-semiconductor field-effect transistors (MOSFETs) and insulated gate bipolar transistors (IGBTs). However, power diodes do not have an inherent parasitic transistor. In this paper, we describe the mechanism triggering SEB in power diodes for the first time using transient device simulation. Initially, generated electron-hole pairs created by incident recoil ions generate transient current, which increases the electron density in the vicinity of the n-/n+ boundary. The space charge effect of the carriers leads to an increase in the strength of the electric field at the n-/n+ boundary. Finally, the onset of impact ionization at the n-/n+ boundary can trigger SEB. Furthermore, this failure is closely related to diode secondary breakdown. It was clarified that the impact ionization at the n-/n+ boundary is a key point of the mechanism triggering SEB in power devices.

  5. Merging metabolism and power: development of a novel photobioelectric device driven by photosynthesis and respiration.

    Directory of Open Access Journals (Sweden)

    Ryan J Powell

    Full Text Available Generation of renewable energy is one of the grand challenges facing our society. We present a new bio-electric technology driven by chemical gradients generated by photosynthesis and respiration. The system does not require pure cultures nor particular species as it works with the core metabolic principles that define phototrophs and heterotrophs. The biology is interfaced with electrochemistry with an alkaline aluminum oxide cell design. In field trials we show the system is robust and can work with an undefined natural microbial community. Power generated is light and photosynthesis dependent. It achieved a peak power output of 33 watts/m(2 electrode. The design is simple, low cost and works with the biological processes driving the system by removing waste products that can impede growth. This system is a new class of bio-electric device and may have practical implications for algal biofuel production and powering remote sensing devices.

  6. Diodes of nanocrystalline SiC on n-/n+-type epitaxial crystalline 6H-SiC

    Science.gov (United States)

    Zheng, Junding; Wei, Wensheng; Zhang, Chunxi; He, Mingchang; Li, Chang

    2018-03-01

    The diodes of nanocrystalline SiC on epitaxial crystalline (n-/n+)6H-SiC wafers were investigated, where the (n+)6H-SiC layer was treated as cathode. For the first unit, a heavily boron doped SiC film as anode was directly deposited by plasma enhanced chemical vapor deposition method on the wafer. As to the second one, an intrinsic SiC film was fabricated to insert between the wafer and the SiC anode. The third one included the SiC anode, an intrinsic SiC layer and a lightly phosphorus doped SiC film besides the wafer. Nanocrystallization in the yielded films was illustrated by means of X-ray diffraction, transmission electronic microscope and Raman spectrum respectively. Current vs. voltage traces of the obtained devices were checked to show as rectifying behaviors of semiconductor diodes, the conduction mechanisms were studied. Reverse recovery current waveforms were detected to analyze the recovery performance. The nanocrystalline SiC films in base region of the fabricated diodes are demonstrated as local regions for lifetime control of minority carriers to improve the reverse recovery properties.

  7. Voltage regulated hybrid DC power source using supercapacitors as energy storage device

    International Nuclear Information System (INIS)

    Ayad, Mohamed-Yacine; Pierfederici, Serge; Rael, Stephane; Davat, Bernard

    2007-01-01

    The management of embedded electrical energy needs a storage system with high dynamic performances in order to shave transient power peaks and to compensate for the intrinsic limitations of the main source. The use of supercapacitors for this storage system is quite suitable because of appropriate electrical characteristics (huge capacitance, weak series resistance, high specific energy, high specific power), direct storage (energy ready for use) and easy control by power electronic conversion. This paper deals with the conception and realisation of a voltage regulated hybrid DC power source using supercapacitors as an auxiliary storage device. Here, we present the structure, control principle and results associated with experimental validation. Our interest will be focused on the management of transient power peaks

  8. Voltage regulated hybrid DC power source using supercapacitors as energy storage device

    Energy Technology Data Exchange (ETDEWEB)

    Ayad, Mohamed-Yacine; Pierfederici, Serge; Rael, Stephane; Davat, Bernard [Groupe de Recherche en Electrotechnique et Electronique de Nancy, Centre National de la Recherche Scientifique (Unite Mixte de Recherche 7037), 2, Avenue de la Foret de Haye, 54516 Vandoeuvre-les-Nancy (France)

    2007-07-15

    The management of embedded electrical energy needs a storage system with high dynamic performances in order to shave transient power peaks and to compensate for the intrinsic limitations of the main source. The use of supercapacitors for this storage system is quite suitable because of appropriate electrical characteristics (huge capacitance, weak series resistance, high specific energy, high specific power), direct storage (energy ready for use) and easy control by power electronic conversion. This paper deals with the conception and realisation of a voltage regulated hybrid DC power source using supercapacitors as an auxiliary storage device. Here, we present the structure, control principle and results associated with experimental validation. Our interest will be focused on the management of transient power peaks. (author)

  9. Stress testing on silicon carbide electronic devices for prognostics and health management.

    Energy Technology Data Exchange (ETDEWEB)

    Kaplar, Robert James; Brock, Reinhard C.; Marinella, Matthew; King, Michael Patrick; Smith, Mark A.; Atcitty, Stanley

    2011-01-01

    Power conversion systems for energy storage and other distributed energy resource applications are among the drivers of the important role that power electronics plays in providing reliable electricity. Wide band gap semiconductors such as silicon carbide (SiC) and gallium nitride (GaN) will help increase the performance and efficiency of power electronic equipment while condition monitoring (CM) and prognostics and health management (PHM) will increase the operational availability of the equipment and thereby make it more cost effective. Voltage and/or temperature stress testing were performed on a number of SiC devices in order to accelerate failure modes and to identify measureable shifts in electrical characteristics which may provide early indication of those failures. Those shifts can be interpreted and modeled to provide prognostic signatures for use in CM and/or PHM. Such experiments will also lead to a deeper understanding of basic device physics and the degradation mechanisms behind failure.

  10. SiC Optically Modulated Field-Effect Transistor

    Science.gov (United States)

    Tabib-Azar, Massood

    2009-01-01

    An optically modulated field-effect transistor (OFET) based on a silicon carbide junction field-effect transistor (JFET) is under study as, potentially, a prototype of devices that could be useful for detecting ultraviolet light. The SiC OFET is an experimental device that is one of several devices, including commercial and experimental photodiodes, that were initially evaluated as detectors of ultraviolet light from combustion and that could be incorporated into SiC integrated circuits to be designed to function as combustion sensors. The ultraviolet-detection sensitivity of the photodiodes was found to be less than desired, such that it would be necessary to process their outputs using high-gain amplification circuitry. On the other hand, in principle, the function of the OFET could be characterized as a combination of detection and amplification. In effect, its sensitivity could be considerably greater than that of a photodiode, such that the need for amplification external to the photodetector could be reduced or eliminated. The experimental SiC OFET was made by processes similar to JFET-fabrication processes developed at Glenn Research Center. The gate of the OFET is very long, wide, and thin, relative to the gates of typical prior SiC JFETs. Unlike in prior SiC FETs, the gate is almost completely transparent to near-ultraviolet and visible light. More specifically: The OFET includes a p+ gate layer less than 1/4 m thick, through which photons can be transported efficiently to the p+/p body interface. The gate is relatively long and wide (about 0.5 by 0.5 mm), such that holes generated at the body interface form a depletion layer that modulates the conductivity of the channel between the drain and the source. The exact physical mechanism of modulation of conductivity is a subject of continuing research. It is known that injection of minority charge carriers (in this case, holes) at the interface exerts a strong effect on the channel, resulting in amplification

  11. Advanced Accelerated Power Cycling Test for Reliability Investigation of Power Device Modules

    DEFF Research Database (Denmark)

    Choi, Uimin; Jørgensen, Søren; Blaabjerg, Frede

    2016-01-01

    This paper presents an apparatus and methodology for an advanced accelerated power cycling test of insulated-gate bipolar transistor (IGBT) modules. In this test, the accelerated power cycling test can be performed under more realistic electrical operating conditions with online wear-out monitoring...... of tested power IGBT module. The various realistic electrical operating conditions close to real three-phase converter applications can be achieved by the simple control method. Further, by the proposed concept of applying the temperature stress, it is possible to apply various magnitudes of temperature...... swing in a short cycle period and to change the temperature cycle period easily. Thanks to a short temperature cycle period, test results can be obtained in a reasonable test time. A detailed explanation of apparatus such as configuration and control methods for the different functions of accelerated...

  12. Adaptive Power Saving Method for Mobile Walking Guidance Device Using Motion Context

    Directory of Open Access Journals (Sweden)

    Jin-Hee Lee

    2015-01-01

    Full Text Available It is important to recognize the motion of the user and the surrounding environment with multiple sensors. We developed a guidance system based on mobile device for visually impaired person that helps the user to walk safely to the destination in the previous study. However, a mobile device having multiple sensors spends more power when the sensors are activated simultaneously and continuously. We propose a method for reducing the power consumption of a mobile device by considering the motion context of the user. We analyze and classify the user’s motion accurately by means of a decision tree and HMM (Hidden Markov Model that exploit the data from a triaxial accelerometer sensor and a tilt sensor. We can reduce battery power consumption by controlling the number of active ultrasonic sensors and the frame rate of the camera used to acquire spatial context around the user. This helps us to extend the operating time of the device and reduce the weight of the device’s built-in battery.

  13. Automatic disease diagnosis using optimised weightless neural networks for low-power wearable devices.

    Science.gov (United States)

    Cheruku, Ramalingaswamy; Edla, Damodar Reddy; Kuppili, Venkatanareshbabu; Dharavath, Ramesh; Beechu, Nareshkumar Reddy

    2017-08-01

    Low-power wearable devices for disease diagnosis are used at anytime and anywhere. These are non-invasive and pain-free for the better quality of life. However, these devices are resource constrained in terms of memory and processing capability. Memory constraint allows these devices to store a limited number of patterns and processing constraint provides delayed response. It is a challenging task to design a robust classification system under above constraints with high accuracy. In this Letter, to resolve this problem, a novel architecture for weightless neural networks (WNNs) has been proposed. It uses variable sized random access memories to optimise the memory usage and a modified binary TRIE data structure for reducing the test time. In addition, a bio-inspired-based genetic algorithm has been employed to improve the accuracy. The proposed architecture is experimented on various disease datasets using its software and hardware realisations. The experimental results prove that the proposed architecture achieves better performance in terms of accuracy, memory saving and test time as compared to standard WNNs. It also outperforms in terms of accuracy as compared to conventional neural network-based classifiers. The proposed architecture is a powerful part of most of the low-power wearable devices for the solution of memory, accuracy and time issues.

  14. Analytical models of lateral power devices with arbitrary vertical doping profiles in the drift region

    International Nuclear Information System (INIS)

    Hua Ting-Ting; Guo Yu-Feng; Yu Ying; Jian Tong; Yao Jia-Fei; Sheu Gene

    2013-01-01

    By solving the 2D Poisson's equation, analytical models are proposed to calculate the surface potential and electric field distributions of lateral power devices with arbitrary vertical doping profiles. The vertical and the lateral breakdown voltages are formulized to quantify the breakdown characteristic in completely-depleted and partially-depleted cases. A new reduced surface field (RESURF) criterion which can be used in various drift doping profiles is further derived for obtaining the optimal trade-off between the breakdown voltage and the on-resistance. Based on these models and the numerical simulation, the electric field modulation mechanism and the breakdown characteristics of lateral power devices are investigated in detail for the uniform, linear, Gaussian, and some discrete doping profiles along the vertical direction in the drift region. Then, the mentioned vertical doping profiles of these devices with the same geometric parameters are optimized, and the results show that the optimal breakdown voltages and the effective drift doping concentrations of these devices are identical, which are equal to those of the uniform-doped device, respectively. The analytical results of these proposed models are in good agreement with the numerical results and the previous experimental results, confirming the validity of the models presented here. (interdisciplinary physics and related areas of science and technology)

  15. Powering autonomous sensors with miniaturized piezoelectric based energy harvesting devices operating at very low frequency

    Science.gov (United States)

    Ferin, G.; Bantignies, C.; Le Khanh, H.; Flesch, E.; Nguyen-Dinh, A.

    2015-12-01

    Harvesting energy from ambient mechanical vibrations is a smart and efficient way to power autonomous sensors and support innovative developments in IoT (Internet of Things), WSN (Wireless Sensor Network) and even implantable medical devices. Beyond the environmental operating conditions, efficiency of such devices is mainly related to energy source properties like the amplitude of vibrations and its spectral contain and some of these applications exhibit a quite low frequency spectrum where harvesting surrounding mechanical energy make sense, typically 5-50Hz for implantable medical devices or 50Hz-150Hz for industrial machines. Harvesting such low frequency vibrations is a challenge since it leads to adapt the resonator geometries to the targeted frequency or to use out-off band indirect harvesting strategies. In this paper we present a piezoelectric based vibrational energy harvesting device (PEH) which could be integrated into a biocompatible package to power implantable sensor or therapeutic medical devices. The presented architecture is a serial bimorph laminated with ultra-thinned (ranging from 15μm to 100μm) outer PZT “skins” that could operate at a “very low frequency”, below 25Hz typically. The core process flow is disclosed and performances highlighted with regards to other low frequency demonstrations.

  16. Multiscale Thermo-Mechanical Design and Analysis of High Frequency and High Power Vacuum Electron Devices

    Science.gov (United States)

    Gamzina, Diana

    Diana Gamzina March 2016 Mechanical and Aerospace Engineering Multiscale Thermo-Mechanical Design and Analysis of High Frequency and High Power Vacuum Electron Devices Abstract A methodology for performing thermo-mechanical design and analysis of high frequency and high average power vacuum electron devices is presented. This methodology results in a "first-pass" engineering design directly ready for manufacturing. The methodology includes establishment of thermal and mechanical boundary conditions, evaluation of convective film heat transfer coefficients, identification of material options, evaluation of temperature and stress field distributions, assessment of microscale effects on the stress state of the material, and fatigue analysis. The feature size of vacuum electron devices operating in the high frequency regime of 100 GHz to 1 THz is comparable to the microstructure of the materials employed for their fabrication. As a result, the thermo-mechanical performance of a device is affected by the local material microstructure. Such multiscale effects on the stress state are considered in the range of scales from about 10 microns up to a few millimeters. The design and analysis methodology is demonstrated on three separate microwave devices: a 95 GHz 10 kW cw sheet beam klystron, a 263 GHz 50 W long pulse wide-bandwidth sheet beam travelling wave tube, and a 346 GHz 1 W cw backward wave oscillator.

  17. Powering autonomous sensors with miniaturized piezoelectric based energy harvesting devices operating at very low frequency

    International Nuclear Information System (INIS)

    Ferin, G; Bantignies, C; Khanh, H Le; Flesch, E; Nguyen-Dinh, A

    2015-01-01

    Harvesting energy from ambient mechanical vibrations is a smart and efficient way to power autonomous sensors and support innovative developments in IoT (Internet of Things), WSN (Wireless Sensor Network) and even implantable medical devices. Beyond the environmental operating conditions, efficiency of such devices is mainly related to energy source properties like the amplitude of vibrations and its spectral contain and some of these applications exhibit a quite low frequency spectrum where harvesting surrounding mechanical energy make sense, typically 5-50Hz for implantable medical devices or 50Hz-150Hz for industrial machines. Harvesting such low frequency vibrations is a challenge since it leads to adapt the resonator geometries to the targeted frequency or to use out-off band indirect harvesting strategies. In this paper we present a piezoelectric based vibrational energy harvesting device (PEH) which could be integrated into a biocompatible package to power implantable sensor or therapeutic medical devices. The presented architecture is a serial bimorph laminated with ultra-thinned (ranging from 15μm to 100μm) outer PZT “skins” that could operate at a “very low frequency”, below 25Hz typically. The core process flow is disclosed and performances highlighted with regards to other low frequency demonstrations. (paper)

  18. Analytical models of lateral power devices with arbitrary vertical doping profiles in the drift region

    Science.gov (United States)

    Hua, Ting-Ting; Guo, Yu-Feng; Yu, Ying; Gene, Sheu; Jian, Tong; Yao, Jia-Fei

    2013-05-01

    By solving the 2D Poisson's equation, analytical models are proposed to calculate the surface potential and electric field distributions of lateral power devices with arbitrary vertical doping profiles. The vertical and the lateral breakdown voltages are formulized to quantify the breakdown characteristic in completely-depleted and partially-depleted cases. A new reduced surface field (RESURF) criterion which can be used in various drift doping profiles is further derived for obtaining the optimal trade-off between the breakdown voltage and the on-resistance. Based on these models and the numerical simulation, the electric field modulation mechanism and the breakdown characteristics of lateral power devices are investigated in detail for the uniform, linear, Gaussian, and some discrete doping profiles along the vertical direction in the drift region. Then, the mentioned vertical doping profiles of these devices with the same geometric parameters are optimized, and the results show that the optimal breakdown voltages and the effective drift doping concentrations of these devices are identical, which are equal to those of the uniform-doped device, respectively. The analytical results of these proposed models are in good agreement with the numerical results and the previous experimental results, confirming the validity of the models presented here.

  19. Development of combined low-emissions burner devices for low-power boilers

    Science.gov (United States)

    Roslyakov, P. V.; Proskurin, Yu. V.; Khokhlov, D. A.

    2017-08-01

    Low-power water boilers are widely used for autonomous heat supply in various industries. Firetube and water-tube boilers of domestic and foreign manufacturers are widely represented on the Russian market. However, even Russian boilers are supplied with licensed foreign burner devices, which reduce their competitiveness and complicate operating conditions. A task of developing efficient domestic low-emissions burner devices for low-power boilers is quite acute. A characteristic property of ignition and fuel combustion in such boilers is their flowing in constrained conditions due to small dimensions of combustion chambers and flame tubes. These processes differ significantly from those in open combustion chambers of high-duty power boilers, and they have not been sufficiently studied yet. The goals of this paper are studying the processes of ignition and combustion of gaseous and liquid fuels, heat and mass transfer and NO x emissions in constrained conditions, and the development of a modern combined low-emissions 2.2 MW burner device that provides efficient fuel combustion. A burner device computer model is developed and numerical studies of its operation on different types of fuel in a working load range from 40 to 100% of the nominal are carried out. The main features of ignition and combustion of gaseous and liquid fuels in constrained conditions of the flame tube at nominal and decreased loads are determined, which differ fundamentally from the similar processes in steam boiler furnaces. The influence of the burner devices design and operating conditions on the fuel underburning and NO x formation is determined. Based on the results of the design studies, a design of the new combined low-emissions burner device is proposed, which has several advantages over the prototype.

  20. SPECIFIC FEATURES OF POWER CONSUMPTION OF LED DEVICES AND ACCOUNTING THEM IN CALCULATION OF ELECTRICAL NETWORKS

    Directory of Open Access Journals (Sweden)

    V. N. Radkevich

    2016-01-01

    Full Text Available The indicators of power consumption of lighting devices based on LEDs are studied depending on the supplied voltage. For the lamp and floodlight with LEDs active and reactive power, current and power factor as a function of voltage (which value changed in the range 200–245 V were experimentally determined. The analysis of experimental data demonstrated that due to the drivers in the specified voltage range the active power consumed by light devices remains practically unchanged. The reactive power of LED devices depends on the supplied voltage and is capacitive in its nature. In contrast with gas-discharge light sources the LED devices under study do not consume reactive power, but generate it. With the change of the supplied voltage from 200 to 245 V the value of the generated reactive power increases to 60 % for the floodlight and 50 % for the lamp. The LED floodlight has a low coefficient of active power. The current consumed by the floodlight has increased by 22 %, and by the lamp – by 13 %. The formulas for determining the maximum value of the length of the calculated section of single-phase group lines were developed, taking into account specific source data. LED light sources tend to feed by electric power by single-phase group lines. The number of lamps connected to single-phase lines is regulated by normative documents. Bearing this in mind as well as the small power of LED sources single-phase group lines are usually performed with conductors of the smallest possible cross section. The limit values of the length of the calculated section that correspond to a predetermined loss of voltage in line with ambient temperature from 15 to 60 °С were determined for them. The calculations demonstrated that for group lines that feed the LEDs, the choice of conductor cross-sections in accordance with permissible voltage loss is not critical. The determinant factor for the choice of the cross-section of the conductors of group electrical

  1. Packaging Technologies for 500C SiC Electronics and Sensors

    Science.gov (United States)

    Chen, Liang-Yu

    2013-01-01

    Various SiC electronics and sensors are currently under development for applications in 500C high temperature environments such as hot sections of aerospace engines and the surface of Venus. In order to conduct long-term test and eventually commercialize these SiC devices, compatible packaging technologies for the SiC electronics and sensors are required. This presentation reviews packaging technologies developed for 500C SiC electronics and sensors to address both component and subsystem level packaging needs for high temperature environments. The packaging system for high temperature SiC electronics includes ceramic chip-level packages, ceramic printed circuit boards (PCBs), and edge-connectors. High temperature durable die-attach and precious metal wire-bonding are used in the chip-level packaging process. A high temperature sensor package is specifically designed to address high temperature micro-fabricated capacitive pressure sensors for high differential pressure environments. This presentation describes development of these electronics and sensor packaging technologies, including some testing results of SiC electronics and capacitive pressure sensors using these packaging technologies.

  2. A Study on the technology of the Protective Device Application for the power Telecommunication Facilities

    Energy Technology Data Exchange (ETDEWEB)

    Lee, B.K.; Lee, S.J.; Choi, H.Y. [Korea Electric Power Research Insitute, Taejeon (Korea, Republic of); Lee, B.H.; Jeon, D.K.; Lee, K.O.; Ahn, C.H.; Kim, S.O.; Kim, J.S. [Electrical Engineering and Science Research Center, Seoul (Korea, Republic of)

    1997-12-31

    In order to protect the power telecommunication system from surge by lightning or switching and ground potential rise, characteristics of surge are analyzed when surge strikes communication system. Surge generator which meets international standard was made and test of protective devices was carried out by using it. Counter measures against surge is established through the analysis of ground potential which varies with transient ground impedance. Also specification for installing protective devices was recommended, which is proper to apply to the field system. (author). 186 refs., 203 figs., 21 tabs.

  3. Compensating for Tissue Changes in an Ultrasonic Power Link for Implanted Medical Devices.

    Science.gov (United States)

    Vihvelin, Hugo; Leadbetter, Jeff; Bance, Manohar; Brown, Jeremy A; Adamson, Robert B A

    2016-04-01

    Ultrasonic power transfer using piezoelectric devices is a promising wireless power transfer technology for biomedical implants. However, for sub-dermal implants where the separation between the transmitter and receiver is on the order of several acoustic wavelengths, the ultrasonic power transfer efficiency (PTE) is highly sensitive to the distance between the transmitter and receiver. This sensitivity can cause large swings in efficiency and presents a serious limitation on battery life and overall performance. A practical ultrasonic transcutaneous energy transfer (UTET) system design must accommodate different implant depths and unpredictable acoustic changes caused by tissue growth, hydration, ambient temperature, and movement. This paper describes a method used to compensate for acoustic separation distance by varying the transmit (Tx) frequency in a UTET system. In a benchtop UTET system we experimentally show that without compensation, power transfer efficiency can range from 9% to 25% as a 5 mm porcine tissue sample is manipulated to simulate in situ implant conditions. Using an active frequency compensation method, we show that the power transfer efficiency can be kept uniformly high, ranging from 20% to 27%. The frequency compensation strategy we propose is low-power, non-invasive, and uses only transmit-side measurements, making it suitable for active implanted medical device applications.

  4. Power accounting of plasma discharges in the linear device Proto-MPEX

    Science.gov (United States)

    Showers, M.; Piotrowicz, P. A.; Beers, C. J.; Biewer, T. M.; Caneses, J.; Canik, J.; Caughman, J. B. O.; Donovan, D. C.; Goulding, R. H.; Lumsdaine, A.; Kafle, N.; Owen, L. W.; Rapp, J.; Ray, H.

    2018-06-01

    Plasma material interaction (PMI) studies are crucial to the successful development of future fusion reactors. Prototype Material Plasma Exposure eXperiment (Proto-MPEX) is a prototype design for the MPEX, a steady-state linear device being developed to study PMI. The primary purpose of Proto-MPEX is developing the plasma heating source concepts for MPEX. A power accounting study of Proto-MPEX works to identify machine operating parameters that could improve its performance, thereby increasing its PMI research capabilities, potentially impacting the MPEX design concept. To build a comprehensive power balance, an analysis of the helicon region has been performed implementing a diagnostic suite and software modeling to identify mechanisms and locations of heat loss from the main plasma. Of the 106.3 kW of input power, up to 90.5% of the power has been accounted for in the helicon region. When the analysis was extended to encompass the device to its end plates, 49.2% of the input power was accounted for and verified diagnostically. Areas requiring further diagnostic analysis are identified. The required improvements will be implemented in future work. The data acquisition and analysis processes will be streamlined to form a working model for future power balance studies of Proto-MPEX. ).

  5. Impact of modulation strategies on power devices loading for 10 MW multilevel wind power converter

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Isidori, Andrea; Rossi, Fabio Mario

    2012-01-01

    This paper focuses on the control and modulation of a three-level Neutral Point Clamped (3L-NPC) back-to-back full scale converter for a 10 MW direct-drive wind turbine, equipped with a Permanent Magnet Synchronous Generator (PMSG). Emphasis is oriented towards the investigation of the power losses...

  6. Deposition of SiC thin films by PECVD

    CERN Document Server

    Cho, N I; Kim, C K

    1999-01-01

    The SiC films were deposited on Si substrate by the decomposition of CH sub 3 SiCl sub 3 (methylthrichlorosilane) molecules in a high frequency discharge field. From the Raman spectra, it is conjectured that the deposited film are formed into the polycrystalline structure. The photon absorption measurement reveal that the band gap of the electron energy state are to be 2.4 eV for SiC, and 2.6 eV for Si sub 0 sub . sub 4 C sub 0 sub . sub 6 , respectively. In the high power density regime, methyl-radicals decompose easily and increases the carbon concentration in plasma and result in the growing films.

  7. A novel multiple super junction power device structure with low specific on-resistance

    International Nuclear Information System (INIS)

    Zhu Hui; Li Haiou; Li Qi; Huang Yuanhao; Xu Xiaoning; Zhao Hailiang

    2014-01-01

    A novel multiple super junction (MSJ) LDMOS power device is proposed to decrease R on due to lateral and vertical interactions between the N-pillar and P-pillar. In the studied device: multiple layers of SJ are introduced oppositely under surface SJ; when compared with 2D-depleting of the conventional super junction (CSJ), a 3D-depleted effect is formed in the MSJ thanks to vertical electric field modulation; and, current distribution is improved by deep drain, which increases the drift doping concentration and results in a lower on-resistance. The high electric field around the drain region by substrate-assisted depleted effect is reduced due to the charge balance result from the electric field shielding effect of the bottom SJ, which causes the uniform electric field in the drift region and the high breakdown voltage. The numerical simulation results indicate that the specific on-resistance of the MSJ device is reduced by 42% compared with that of CSJ device, while maintaining a high breakdown voltage; the cell pitch of the device is 12 μm. (semiconductor devices)

  8. Transdermal power transfer for recharging implanted drug delivery devices via the refill port.

    Science.gov (United States)

    Evans, Allan T; Chiravuri, Srinivas; Gianchandani, Yogesh B

    2010-04-01

    This paper describes a system for transferring power across a transdermal needle into a smart refill port for recharging implantable drug delivery systems. The device uses a modified 26 gauge (0.46 mm outer diameter) Huber needle with multiple conductive elements designed to couple with mechanical springs in the septum of the refill port of a drug delivery device to form an electrical connection that can sustain the current required to recharge a battery during a reservoir refill session. The needle is fabricated from stainless steel coated with Parylene, and the refill port septum is made from micromachined stainless steel contact springs and polydimethylsiloxane. The device properties were characterized with dry and wet ambient conditions. The needle and port pair had an average contact resistance of less than 2 Omega when mated in either environment. Electrical isolation between the system, the liquid in the needle lumen, and surrounding material has been demonstrated. The device was used to recharge a NiMH battery with currents up to 500 mA with less than 15 degrees C of resistive heating. The system was punctured 100 times to provide preliminary information with regard to device longevity, and exhibited about 1 Omega variation in contact resistance. The results suggest that this needle and refill port system can be used in an implant to enable battery recharging. This allows for smaller batteries to be used and ultimately increases the volume efficiency of an implantable drug delivery device.

  9. Systems and methods for tracking a device in zero-infrastructure and zero-power conditions, and a tracking device therefor

    KAUST Repository

    Shamim, Atif

    2017-03-23

    Disclosed are embodiments for a tracking device having multiple layers of localization and communication capabilities, and particularly having the ability to operate in zero-infrastructure or zero-power conditions. Also disclosed are methods and systems that enhance location determination in zero-infrastructure and zero-power conditions. In one example, a device, system and/or method includes an infrastructure-based localization module, an infrastructure-less localization module and a passive module that can utilize at least two of the modules to determine a location of the tracking device.

  10. Methods to enhance blanket power density in low-power fusion devices

    International Nuclear Information System (INIS)

    Hsu, P.Y.; Miller, L.G.; Bohn, T.S.; Deis, G.A.; Longhurst, G.R.; Masson, L.S.; Wessol, D.E.; Abdou, M.A.

    1982-06-01

    The overall objective of this task is to investigate the extent to which the power density in the FED breeder blanket test modules can be enhanced by artificial means. Assuming a viable approach can be developed, it will allow testing of advanced reactor blanket modules on INTOR at representative conditions. The tentative approach adopted for this task consists of three parts. First, the requirements for augmented heating of the test module are outlined for different applications of interest. Second, methods are identified which have potential for augmenting the heating power in a test module, and this list of methods is narrowed to those which appear to be most useful. Finally, these methods are examined in more detail to determine the practical benefits of employing each

  11. Estimation and harvesting of human heat power for wearable electronic devices

    International Nuclear Information System (INIS)

    Dziurdzia, P; Brzozowski, I; Bratek, P; Gelmuda, W; Kos, A

    2016-01-01

    The paper deals with the issue of self-powered wearable electronic devices that are capable of harvesting free available energy dissipated by the user in the form of human heat. The free energy source is intended to be used as a secondary power source supporting primary battery in a sensor bracelet. The main scope of the article is a presentation of the concept for a measuring setup used to quantitative estimation of heat power sources in different locations over the human body area. The crucial role in the measurements of the human heat plays a thermoelectric module working in the open circuit mode. The results obtained during practical tests are confronted with the requirements of the dedicated thermoelectric generator. A prototype design of a human warmth energy harvester with an ultra-low power DC-DC converter based on the LTC3108 circuit is analysed

  12. Influence of TCSC Devices on Congestion Management in a Deregulated Power System Using Evolutionary Programming Technique

    Science.gov (United States)

    Ananthichristy, A., Dr.; Elanthirayan, R.; Brindha, R., Dr.; Siddhiq, M. S.; Venkatesh, N.; Harshit, M. V.; Nikhilreddy, M.

    2018-04-01

    Congestion management is one of the technical challenges in power system deregulation. In deregulated electricity market it may always not be possible to dispatch all of the contracted power transactions due to congestion of the transmission corridors. Transmission congestion occurs when there is insufficient transmission capacity to simultaneously accommodate all constraints for transmission of a line. Flexible Alternative Current Transmission System (FACTS) devices can be an alternative to reduce the flows in the heavily loaded lines, resulting in an increased loadability, low system loss, improved stability of the network, reduced cost of production and fulfilled contractual requirement by controlling the power flow in the network. A method to determine the optimal location of FACTS has been suggested based on reduction of total system VAR power losses. The simulation was done on IEEE 14 bus system and results were obtained.

  13. Theoretical and experimental study of a wireless power supply system for moving low power devices in ferromagnetic and conductive medium

    Science.gov (United States)

    Safour, Salaheddine; Bernard, Yves

    2017-10-01

    This paper focuses on the design of a wireless power supply system for low power devices (e.g. sensors) located in harsh electromagnetic environment with ferromagnetic and conductive materials. Such particular environment could be found in linear and rotating actuators. The studied power transfer system is based on the resonant magnetic coupling between a fixed transmitter coil and a moving receiver coil. The technique was utilized successfully for rotary machines. The aim of this paper is to extend the technique to linear actuators. A modeling approach based on 2D Axisymmetric Finite Element model and an electrical lumped model based on the two-port network theory is introduced. The study shows the limitation of the technique to transfer the required power in the presence of ferromagnetic and conductive materials. Parametric and circuit analysis were conducted in order to design a resonant magnetic coupler that ensures good power transfer capability and efficiency. A design methodology is proposed based on this study. Measurements on the prototype show efficiency up to 75% at a linear distance of 20 mm.

  14. Selected fault testing of electronic isolation devices used in nuclear power plant operation

    International Nuclear Information System (INIS)

    Villaran, M.; Hillman, K.; Taylor, J.; Lara, J.; Wilhelm, W.

    1994-05-01

    Electronic isolation devices are used in nuclear power plants to provide electrical separation between safety and non-safety circuits and systems. Major fault testing in an earlier program indicated that some energy may pass through an isolation device when a fault at the maximum credible potential is applied in the transverse mode to its output terminals. During subsequent field qualification testing of isolators, concerns were raised that the worst case fault, that is, the maximum credible fault (MCF), may not occur with a fault at the maximum credible potential, but rather at some lower potential. The present test program investigates whether problems can arise when fault levels up to the MCF potential are applied to the output terminals of an isolator. The fault energy passed through an isolated device during a fault was measured to determine whether the levels are great enough to potentially damage or degrade performance of equipment on the input (Class 1E) side of the isolator

  15. MODELING OF POWER SYSTEMS AND TESTING OF RELAY PROTECTION DEVICES IN REAL AND MODEL TIME

    Directory of Open Access Journals (Sweden)

    I. V. Novash

    2017-01-01

    Full Text Available The methods of modelling of power system modes and of testing of relay protection devices with the aid the simulation complexes in real time and with the help of computer software systems that enables the simulation of virtual time scale are considered. Information input protection signals in the simulation of the virtual model time are being obtained in the computational experiment, whereas the tests of protective devices are carried out with the help of hardware and software test systems with the use of estimated input signals. Study of power system stability when modes of generating and consuming electrical equipment and conditions of devices of relay protection are being changed requires testing with the use of digital simulators in a mode of a closed loop. Herewith feedbacks between a model of the power system operating in a real time and external devices or their models must be determined (modelled. Modelling in real time and the analysis of international experience in the use of digital simulation power systems for real-time simulation (RTDS simulator have been fulfilled. Examples are given of the use of RTDS systems by foreign energy companies to test relay protection systems and control, to test the equipment and devices of automatic control, analysis of cyber security and evaluation of the operation of energy systems under different scenarios of occurrence of emergency situations. Some quantitative data on the distribution of RTDS in different countries and Russia are presented. It is noted that the leading energy universities of Russia use the real-time simulation not only to solve scientific and technical problems, but also to conduct training and laboratory classes on modelling of electric networks and anti-emergency automatic equipment with the students. In order to check serviceability of devices of relay protection without taking into account the reaction of the power system tests can be performed in an open loop mode with the

  16. Performance evaluation of hybrid VLC using device cost and power over data throughput criteria

    Science.gov (United States)

    Lee, C. C.; Tan, C. S.; Wong, H. Y.; Yahya, M. B.

    2013-09-01

    Visible light communication (VLC) technology has attained its attention in both academic and industry lately. It is determined by the development of light emitting diode (LED) technology for solid-state lighting (SSL).It has great potential to gradually replace radio frequency (RF) wireless technology because it offers unregulated and unlicensed bandwidth to withstand future demand of indoor wireless access to real-time bandwidth-demanding applications. However, it was found to provide intrusive uplink channel that give rise to unpleasant irradiance from the user device which could interfere with the downlink channel of VLC and hence limit mobility to users as a result of small coverage (field of view of VLC).To address this potential problem, a Hybrid VLC system which integrates VLC (for downlink) and RF (for uplink) technology is proposed. It offers a non-intrusive RF back channel that provides high throughput VLC and maintains durability with conventional RF devices. To deploy Hybrid VLC system in the market, it must be energy and cost saving to attain its equivalent economical advantage by comparing to existing architecture that employs fluorescent or LED lights with RF technology. In this paper, performance evaluation on the proposed hybrid system was carried out in terms of device cost and power consumption against data throughput. Based on our simulation, Hybrid VLC system was found to reduce device cost by 3% and power consumption by 68% when compares to fluorescent lights with RF technology. Nevertheless, when it is compared to LED lights with RF technology, our proposed hybrid system is found to achieve device cost saving as high as 47% and reduced power consumption by 49%. Such promising results have demonstrated that Hybrid VLC system is a feasible solution and has paved the way for greater cost saving and energy efficient compares with the current RF architecture even with the increasing requirement of indoor area coverage.

  17. Acoustic Levitator Power Device: Study of Ethylene-Glycol Water Mixtures

    Science.gov (United States)

    Caccamo, M. T.; Cannuli, A.; Calabrò, E.; Magazù, S.

    2017-05-01

    Acoustic levitator power device is formed by two vertically and opposed high output acoustic transducers working at 22 kHz frequency and produces sound pressure levels of 160 dB. The acoustic waves are monitored from an oscilloscope using a signal amplifier. The ability to perform contactless measurements, avoidance of undesired contamination from the container, are some of advantages of this apparatus. Acoustic levitation can be also used for sample preparation of high concentrated mixtures starting from solutions. In the present paper, an acoustic levitator power device is employed to collect data on levitated water mixtures of Ethylene Glycol (EG) which are then analysed by Infra-Red spectroscopy. The study allows to follow the drying process versus time and to obtain a gel-like compound characterized by an extended chemical crosslinking.

  18. Electron beam gun with kinematic coupling for high power RF vacuum devices

    Science.gov (United States)

    Borchard, Philipp

    2016-11-22

    An electron beam gun for a high power RF vacuum device has components joined by a fixed kinematic coupling to provide both precise alignment and high voltage electrical insulation of the components. The kinematic coupling has high strength ceramic elements directly bonded to one or more non-ductile rigid metal components using a high temperature active metal brazing alloy. The ceramic elements have a convex surface that mates with concave grooves in another one of the components. The kinematic coupling, for example, may join a cathode assembly and/or a beam shaping focus electrode to a gun stem, which is preferably composed of ceramic. The electron beam gun may be part of a high power RF vacuum device such as, for example, a gyrotron, klystron, or magnetron.

  19. Self-healing of cracks in Ag joining layer for die-attachment in power devices

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chuantong, E-mail: chenchuantong@sanken.osaka-u.ac.jp; Nagao, Shijo; Suganuma, Katsuaki; Jiu, Jinting; Zhang, Hao; Sugahara, Tohru [Institute of Scientific and Industrial Research, Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047 (Japan); Iwashige, Tomohito; Sugiura, Kazuhiko; Tsuruta, Kazuhiro [Research Division 3, Denso Corporation, Komenoki-cho, Minamiyama 500-1, Nissin, Aichi 470-0111 (Japan)

    2016-08-29

    Sintered silver (Ag) joining has attracted significant interest in power devices modules for its ability to form stable joints with a porous interconnection layer. A function for the self-healing of cracks in sintered porous Ag interlayers at high temperatures is discovered and reported here. A crack which was prepared on a Ag joining layer was closed after heating at 200 °C in air. The tensile strength of pre-cracked Ag joining layer specimens recovers to the value of non-cracked specimens after heating treatment. Transmission electron microscopy (TEM) was used to probe the self-healing mechanism. TEM images and electron diffraction patterns show that a large quantity of Ag nanoparticles formed at the gap with the size less than 10 nm, which bridges the crack in the self-healing process. This discovery provides additional motivation for the application of Ag as an interconnection material for power devices at high temperature.

  20. Evaporation and condensation devices for passive heat removal systems in nuclear power engineering

    International Nuclear Information System (INIS)

    Gershuni, A.N.; Pis'mennyj, E.N.; Nishchik, A.P.

    2016-01-01

    The paper justifies advantages of evaporation and condensation heat transfer devices as means of passive heat removal and thermal shielding in nuclear power engineering. The main thermophysical factors that limit heat transfer capacity of evaporation and condensation systems have been examined in the research. The results of experimental studies of heat engineering properties of elongated (8-m) vertically oriented evaporation and condensation devices (two-phase thermosyphons), which showed a high enough heat transfer capacity, as well as stability and reliability both in steady state and in start-up modes, are provided. The paper presents the examples of schematic designs of evaporation and condensation systems for passive heat removal and thermal shielding in application to nuclear power equipment

  1. Robust and Imperceptible Watermarking of Video Streams for Low Power Devices

    Science.gov (United States)

    Ishtiaq, Muhammad; Jaffar, M. Arfan; Khan, Muhammad A.; Jan, Zahoor; Mirza, Anwar M.

    With the advent of internet, every aspect of life is going online. From online working to watching videos, everything is now available on the internet. With the greater business benefits, increased availability and other online business advantages, there is a major challenge of security and ownership of data. Videos downloaded from an online store can easily be shared among non-intended or unauthorized users. Invisible watermarking is used to hide copyright protection information in the videos. The existing methods of watermarking are less robust and imperceptible and also the computational complexity of these methods does not suit low power devices. In this paper, we have proposed a new method to address the problem of robustness and imperceptibility. Experiments have shown that our method has better robustness and imperceptibility as well as our method is computationally efficient than previous approaches in practice. Hence our method can easily be applied on low power devices.

  2. EXPERIMENTAL VERIFICATION OF COMPUTER MODEL OF COOLING SYSTEM FOR POWERFUL SEMI- CONDUCTOR DEVICE

    Directory of Open Access Journals (Sweden)

    I. A. Khorunzhii

    2007-01-01

    Full Text Available A cooling system for powerful semi-conductor device (power -1 kW consisting of a pin-type radiator and a body is considered in the paper. Cooling is carried out by forced convection of a coolant. Calculated values of temperatures on the radiator surface and experimentally measured values of temperatures in the same surface points have been compared in the paper. It has been shown that the difference between calculated and experimentally measured temperatures does not exceed 0,1-0,2 °C and it is comparable with experimental error value. The given results confirm correctness of a computer model.

  3. Low power digital communication in implantable devices using volume conduction of biological tissues.

    Science.gov (United States)

    Yao, Ning; Lee, Heung-No; Sclabassi, R J; Sun, Mingui

    2006-01-01

    This work investigates the data communication problem of implantable devices using fundamental theories in communications. We utilize the volume conduction property of biological tissues to establish a digital communications link. Data obtained through animal experiments are used to analyze the time and frequency response of the volume conduction channel as well as to characterize the biological signals and noises present in the system. A low power bandwidth efficient channel-coded modulation scheme is proposed to conserve battery power and reduce the health risks associated.

  4. Magnetostrictive device for high-temperature sound and vibration measurement in nuclear power stations

    International Nuclear Information System (INIS)

    Hans, R.; Podgorski, J.

    1977-01-01

    The demands on the monitoring systems in nuclear power stations are increasing continuously, not only because of more stringent safety requirements but also for reasons of plant availability and thus economic efficiency. The noise and vibration measurements which therefore have to be taken make it necessary to provide measuring devices with a high degree of efficiency, adequate sensitivity and resistance to high temperatures, radiation and corrosion. Probes using the magnetostrictive effect, whereby a ferromagnetic core changes its length in a magnetic field - a phenomenon which has been known for approximately fifty years - fulfill all the conditions for application in nuclear power stations. (orig.) [de

  5. Fire protection devices in the controlled region of GKN nuclear power station

    International Nuclear Information System (INIS)

    Bernhardt, S.; Grauf, E.

    1976-01-01

    In the GKN nuclear power station ('Neckar reactor'), an 805 MW PWR reactor whose start-up is scheduled for the near future, fire protection measures have been realized that go far beyond those realized in other German nuclear power stations until now. One of the main reasons is that the authorities have been sensibilized by a fire in the refuelling cavity during construction and by the Browns Ferry fire and are therefore extremely thorough in their examination. Further subsections have been added to the fire prevention sections in order to provide better quenching devices for potential fire sites. (orig./AK) [de

  6. Field emission device driven by self-powered contact-electrification: Simulation and experimental analysis

    Science.gov (United States)

    Chen, Xiangyu; Jiang, Tao; Sun, Zhuo; Ou-Yang, Wei

    2015-09-01

    A self-powered field emission device (FED) driven by a single-electrode tribo-electric nanogenerator (TENG) is demonstrated. The mechanical motion works as both a power supply to drive the FED and a control unit to regulate the amount of emitted electrons. By using the Fowler-Nordheim equation and Kirchhoff laws, a theoretical model of this self-powered FED is proposed, and accordingly the real-time output characteristics of the device are systematically investigated. It is found that the motion distance of the TENG controls switch-on of the FED and determines the charge amount for emission, while the motion velocity regulates the amplitude of emission current. The minimum contact area for the TENG to generate field emission is about 9 cm2, which can be improved by optimizing FED structure and the tribo-materials of TENG. The demonstrated concept of this self-powered FED as well as the proposed physical analysis can serve as guidance for further applications of FED in such fields of self-powered electronics and soft electronics.

  7. Field emission device driven by self-powered contact-electrification: Simulation and experimental analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiangyu, E-mail: chenxiangyu@binn.cas.cn, E-mail: ouyangwei@phy.ecnu.edu.cn; Jiang, Tao [Beijing Institute of Nanoenergy and Nanosystems, Chinese Academy of Sciences, Beijing 100083 (China); Sun, Zhuo; Ou-Yang, Wei, E-mail: chenxiangyu@binn.cas.cn, E-mail: ouyangwei@phy.ecnu.edu.cn [Engineering Research Center for Nanophotonics and Advanced Instrument, Ministry of Education, Department of Physics, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062 (China)

    2015-09-14

    A self-powered field emission device (FED) driven by a single-electrode tribo-electric nanogenerator (TENG) is demonstrated. The mechanical motion works as both a power supply to drive the FED and a control unit to regulate the amount of emitted electrons. By using the Fowler-Nordheim equation and Kirchhoff laws, a theoretical model of this self-powered FED is proposed, and accordingly the real-time output characteristics of the device are systematically investigated. It is found that the motion distance of the TENG controls switch-on of the FED and determines the charge amount for emission, while the motion velocity regulates the amplitude of emission current. The minimum contact area for the TENG to generate field emission is about 9 cm{sup 2}, which can be improved by optimizing FED structure and the tribo-materials of TENG. The demonstrated concept of this self-powered FED as well as the proposed physical analysis can serve as guidance for further applications of FED in such fields of self-powered electronics and soft electronics.

  8. Field emission device driven by self-powered contact-electrification: Simulation and experimental analysis

    International Nuclear Information System (INIS)

    Chen, Xiangyu; Jiang, Tao; Sun, Zhuo; Ou-Yang, Wei

    2015-01-01

    A self-powered field emission device (FED) driven by a single-electrode tribo-electric nanogenerator (TENG) is demonstrated. The mechanical motion works as both a power supply to drive the FED and a control unit to regulate the amount of emitted electrons. By using the Fowler-Nordheim equation and Kirchhoff laws, a theoretical model of this self-powered FED is proposed, and accordingly the real-time output characteristics of the device are systematically investigated. It is found that the motion distance of the TENG controls switch-on of the FED and determines the charge amount for emission, while the motion velocity regulates the amplitude of emission current. The minimum contact area for the TENG to generate field emission is about 9 cm 2 , which can be improved by optimizing FED structure and the tribo-materials of TENG. The demonstrated concept of this self-powered FED as well as the proposed physical analysis can serve as guidance for further applications of FED in such fields of self-powered electronics and soft electronics

  9. The physics of epitaxial graphene on SiC(0001)

    International Nuclear Information System (INIS)

    Kageshima, H; Hibino, H; Tanabe, S

    2012-01-01

    Various physical properties of epitaxial graphene grown on SiC(0001) are studied. First, the electronic transport in epitaxial bilayer graphene on SiC(0001) and quasi-free-standing bilayer graphene on SiC(0001) is investigated. The dependences of the resistance and the polarity of the Hall resistance at zero gate voltage on the top-gate voltage show that the carrier types are electron and hole, respectively. The mobility evaluated at various carrier densities indicates that the quasi-free-standing bilayer graphene shows higher mobility than the epitaxial bilayer graphene when they are compared at the same carrier density. The difference in mobility is thought to come from the domain size of the graphene sheet formed. To clarify a guiding principle for controlling graphene quality, the mechanism of epitaxial graphene growth is also studied theoretically. It is found that a new graphene sheet grows from the interface between the old graphene sheets and the SiC substrate. Further studies on the energetics reveal the importance of the role of the step on the SiC surface. A first-principles calculation unequivocally shows that the C prefers to release from the step edge and to aggregate as graphene nuclei along the step edge rather than be left on the terrace. It is also shown that the edges of the existing graphene more preferentially absorb the isolated C atoms. For some annealing conditions, experiments can also provide graphene islands on SiC(0001) surfaces. The atomic structures are studied theoretically together with their growth mechanism. The proposed embedded island structures actually act as a graphene island electronically, and those with zigzag edges have a magnetoelectric effect. Finally, the thermoelectric properties of graphene are theoretically examined. The results indicate that reducing the carrier scattering suppresses the thermoelectric power and enhances the thermoelectric figure of merit. The fine control of the Fermi energy position is thought to

  10. Development of a power-assisted lifting device for construction and periodic inspection

    International Nuclear Information System (INIS)

    Hayatsu, M.; Yamada, M.; Takasu, H.; Tagawa, Y.; Kajiwara, K.

    2001-01-01

    This study focuses on the control system design and control performance of a power-assisted lifting device. The device consists of several electric chain-blocks, each controlled by force sensors and a CPU. The mechanism is as follows: (1) Force sensors detect any chain tension changes (by human force), (2) The CPU calculates the required output, (3) Electric chain-blocks move the object in the intended direction. The feature of this device is that it does not require any information related to the suspension points of the electric chain-blocks. The controller was designed using the H method, which considers disturbances and aims to provide robust stability under the operation conditions of construction verified through experiments using a 700 kg steel dummy mass (control object) suspended by four electric chain-blocks. In the experiments, the controller, which was designed using the H method, was compared to the PI controller method, and the effectiveness of the H controller was proven. A control object could be moved, translated, and rotated by human force (of less than 10 kg). Positioning performance errors were suppressed to less than 0.5 mm, and operation time was reduced by about 50%. This device will improve working efficiency and rationalize lifting operations in nuclear power plants. (author)

  11. Toward Wearable Self-Charging Power Systems: The Integration of Energy-Harvesting and Storage Devices.

    Science.gov (United States)

    Pu, Xiong; Hu, Weiguo; Wang, Zhong Lin

    2018-01-01

    One major challenge for wearable electronics is that the state-of-the-art batteries are inadequate to provide sufficient energy for long-term operations, leading to inconvenient battery replacement or frequent recharging. Other than the pursuit of high energy density of secondary batteries, an alternative approach recently drawing intensive attention from the research community, is to integrate energy-generation and energy-storage devices into self-charging power systems (SCPSs), so that the scavenged energy can be simultaneously stored for sustainable power supply. This paper reviews recent developments in SCPSs with the integration of various energy-harvesting devices (including piezoelectric nanogenerators, triboelectric nanogenerators, solar cells, and thermoelectric nanogenerators) and energy-storage devices, such as batteries and supercapacitors. SCPSs with multiple energy-harvesting devices are also included. Emphasis is placed on integrated flexible or wearable SCPSs. Remaining challenges and perspectives are also examined to suggest how to bring the appealing SCPSs into practical applications in the near future. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Development of a power-assisted lifting device for construction and periodic inspection

    Energy Technology Data Exchange (ETDEWEB)

    Hayatsu, M.; Yamada, M.; Takasu, H. [Hitachi Plant Engineering and Construction, Chiba-ken (Japan); Tagawa, Y. [Tokyo Univ. of Agriculture and Technology (Japan); Kajiwara, K. [National Research Institute for Earth Science and Disaster Prevention, Tokyo (Japan)

    2001-07-01

    This study focuses on the control system design and control performance of a power-assisted lifting device. The device consists of several electric chain-blocks, each controlled by force sensors and a CPU. The mechanism is as follows: (1) Force sensors detect any chain tension changes (by human force), (2) The CPU calculates the required output, (3) Electric chain-blocks move the object in the intended direction. The feature of this device is that it does not require any information related to the suspension points of the electric chain-blocks. The controller was designed using the H method, which considers disturbances and aims to provide robust stability under the operation conditions of construction verified through experiments using a 700 kg steel dummy mass (control object) suspended by four electric chain-blocks. In the experiments, the controller, which was designed using the H method, was compared to the PI controller method, and the effectiveness of the H controller was proven. A control object could be moved, translated, and rotated by human force (of less than 10 kg). Positioning performance errors were suppressed to less than 0.5 mm, and operation time was reduced by about 50%. This device will improve working efficiency and rationalize lifting operations in nuclear power plants. (author)

  13. Complex programmable logic device based alarm sequencer for nuclear power plants

    International Nuclear Information System (INIS)

    Khedkar, Ravindra; Solomon, J. Selva; KrishnaKumar, B.

    2001-01-01

    Complex Programmable Logic Device based Alarm Sequencer is an instrument, which detects alarms, memorizes them and displays the sequences of occurrence of alarms. It caters to sixteen alarm signals and distinguishes the sequence among any two alarms with a time resolution of 1 ms. The system described has been designed for continuous operation in process plants, nuclear power plants etc. The system has been tested and found to be working satisfactorily. (author)

  14. Vertical GaN Devices for Power Electronics in Extreme Environments

    Science.gov (United States)

    2016-03-31

    Vertical GaN Devices for Power Electronics in Extreme Environments Isik C. Kizilyalli (1), Robert J. Kaplar (2), O. Aktas (1), A. M. Armstrong (2...electronics applications. In this paper vertical p-n diodes and transistors fabricated on pseudo bulk low defect density (104 to 106 cm-2) GaN substrates are...discussed. Homoepitaxial MOCVD growth of GaN on its native substrate and being able to control doping has allowed the realization of vertical

  15. Power Devices Loading in Multilevel Converters for 10 MW Wind Turbines

    DEFF Research Database (Denmark)

    Ma, Ke; Blaabjerg, Frede; Xu, Dehong

    2011-01-01

    Several promising multilevel converter solutions for 10 MW wind turbines using permanent magnet synchronous generators are proposed, designed and compared both with one-stage gear-box drive and direct drive systems. The current and loss distributions, as well as the utilization of power devices......-level NeutralPoint-Clamped topology with both the direct-drive and one-stage gear box drive systems....

  16. Device for the analysis of feedwater and condensation samples from power plants

    International Nuclear Information System (INIS)

    Mostofin, A.A.; Sorokina, N.S.

    1978-01-01

    An improved version of a device for automatic measurement of the salt and NH 3 contents of feedwater and condensate samples from nuclear power plants is described. Only one sample is required for determining both values. The invention proposes on the one hand to change the dimensions of a throttle opening and on the other to install a second measuring instrument (conductivity measuring instrument). (UWI) [de

  17. Water quality control method and device for nuclear power plant and nuclear power plant

    International Nuclear Information System (INIS)

    Nagase, Makoto; Asakura, Yamato; Uetake, Naoto; Sawa, Toshio; Uchida, Shunsuke; Takeda, Renzo; Osumi, Katsumi.

    1993-01-01

    In a BWR type nuclear power plant, water quality of coolants is controlled so as to lower deposition rate of Co ions in reactor water on a fuel cladding tube. The water quality control method includes (1) decreasing an iron concentration in feedwater to less than 0.1ppb, (2) adjusting coolants weakly acidic and (3) controlling dissolved oxygen concentration in reactor water to 20ppb. This can decrease 60 Co ion concentration even if 60 Co ion concentration is increased by the change of environment for the operation in future, such as an operation with hydrogen injection and extention of fuel burnup degree. (T.M.)

  18. An optimized electronic device for solar power harvesting dedicated to wireless sensor networks

    Energy Technology Data Exchange (ETDEWEB)

    Le Cam, Vincent; Le Maulf, Regis; Lemarchand, Laurent; Martin, William; Le Pen, Mathieu [LUNAM Univ., Bouguenais (France). IFSTTAR, MACS Dept.

    2012-07-01

    For economics as for practical reasons, this last decade, the use and dissemination of wireless sensor networks (WSN) became obvious; particularly in structural heath monitoring (SHM) use-cases where distances between sensors could be long and access to the structure quite difficult. Even if efforts are leaded to design small components and RF modules that ask for low-power, the need of an external source is often necessary. After have acquired knowledge in solar cells as in batteries technologies and methods to control charge/discharge phases as in optimizing algorithms, IFSTTAR laboratory has designed an electronic device that integrates those progress. This electronic device has a quite generic mission: for a panel of batteries chemistry (Lithium, NiMh) and a panel of solar cells sources (frome mW to some W), the system acts as an improved battery charger whatever the load ask for power. The system applies control algorithms based on battery capacity and chemistry profile. It also applies the MPPT (Maximum Power Point Tracking) algorithm. At any time, battery State Of Charge (SOC) can be requested via I2C bus as well as a warning signal is output when SOC becomes critical. Through standard pin connectors and a simple I2C interface, the system can be used by many wireless devices (sensors) that have to run autonomously. After the presentation of this system, a focus on its application on a real use-case will be given. (orig.)

  19. InP-based photonic integrated circuit platform on SiC wafer.

    Science.gov (United States)

    Takenaka, Mitsuru; Takagi, Shinichi

    2017-11-27

    We have numerically investigated the properties of an InP-on-SiC wafer as a photonic integrated circuit (PIC) platform. By bonding a thin InP-based semiconductor on a SiC wafer, SiC can be used as waveguide cladding, a heat sink, and a support substrate simultaneously. Since the refractive index of SiC is sufficiently low, PICs can be fabricated using InP-based strip and rib waveguides with a minimum bend radius of approximately 7 μm. High-thermal-conductivity SiC underneath an InP-based waveguide core markedly improves heat dissipation, resulting in superior thermal properties of active devices such as laser diodes. The InP-on-SiC wafer has significantly smaller thermal stress than InP-on-SiO 2 /Si wafer, which prevents the thermal degradation of InP-based devices during high-temperature processes. Thus, InP on SiC provides an ideal platform for high-performance PICs.

  20. Implementation methodology for interoperable personal health devices with low-voltage low-power constraints.

    Science.gov (United States)

    Martinez-Espronceda, Miguel; Martinez, Ignacio; Serrano, Luis; Led, Santiago; Trigo, Jesús Daniel; Marzo, Asier; Escayola, Javier; Garcia, José

    2011-05-01

    Traditionally, e-Health solutions were located at the point of care (PoC), while the new ubiquitous user-centered paradigm draws on standard-based personal health devices (PHDs). Such devices place strict constraints on computation and battery efficiency that encouraged the International Organization for Standardization/IEEE11073 (X73) standard for medical devices to evolve from X73PoC to X73PHD. In this context, low-voltage low-power (LV-LP) technologies meet the restrictions of X73PHD-compliant devices. Since X73PHD does not approach the software architecture, the accomplishment of an efficient design falls directly on the software developer. Therefore, computational and battery performance of such LV-LP-constrained devices can even be outperformed through an efficient X73PHD implementation design. In this context, this paper proposes a new methodology to implement X73PHD into microcontroller-based platforms with LV-LP constraints. Such implementation methodology has been developed through a patterns-based approach and applied to a number of X73PHD-compliant agents (including weighing scale, blood pressure monitor, and thermometer specializations) and microprocessor architectures (8, 16, and 32 bits) as a proof of concept. As a reference, the results obtained in the weighing scale guarantee all features of X73PHD running over a microcontroller architecture based on ARM7TDMI requiring only 168 B of RAM and 2546 B of flash memory.

  1. Power Electronics Thermal Management R&D

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Gilbert; Bennion, Kevin

    2016-06-08

    This project will develop thermal management strategies to enable efficient and high-temperature wide-bandgap (WBG)-based power electronic systems (e.g., emerging inverter and DC-DC converter designs). The use of WBG-based devices in automotive power electronics will improve efficiency and increase driving range in electric-drive vehicles; however, the implementation of this technology is limited, in part, due to thermal issues. This project will develop system-level thermal models to determine the thermal limitations of current automotive power modules under elevated device temperature conditions. Additionally, novel cooling concepts and material selection will be evaluated to enable high-temperature silicon and WBG devices in power electronics components. WBG devices (silicon carbide [SiC], gallium nitride [GaN]) promise to increase efficiency, but will be driven as hard as possible. This creates challenges for thermal management and reliability.

  2. Power-Management Techniques for Wireless Sensor Networks and Similar Low-Power Communication Devices Based on Nonrechargeable Batteries

    Directory of Open Access Journals (Sweden)

    Agnelo Silva

    2012-01-01

    Full Text Available Despite the well-known advantages of communication solutions based on energy harvesting, there are scenarios where the absence of batteries (supercapacitor only or the use of rechargeable batteries is not a realistic option. Therefore, the alternative is to extend as much as possible the lifetime of primary cells (nonrechargeable batteries. By assuming low duty-cycle applications, three power-management techniques are combined in a novel way to provide an efficient energy solution for wireless sensor networks nodes or similar communication devices powered by primary cells. Accordingly, a customized node is designed and long-term experiments in laboratory and outdoors are realized. Simulated and empirical results show that the battery lifetime can be drastically enhanced. However, two trade-offs are identified: a significant increase of both data latency and hardware/software complexity. Unattended nodes deployed in outdoors under extreme temperatures, buried sensors (underground communication, and nodes embedded in the structure of buildings, bridges, and roads are some of the target scenarios for this work. Part of the provided guidelines can be used to extend the battery lifetime of communication devices in general.

  3. Effects of SiC amount on phase compositions and properties of Ti3SiC2-based composites

    Institute of Scientific and Technical Information of China (English)

    蔡艳芝; 殷小玮; 尹洪峰

    2015-01-01

    The phase compositions and properties of Ti3SiC2-based composites with SiC addition of 5%−30% in mass fraction fabricated by in-situ reaction and hot pressing sintering were studied. SiC addition effectively prevented TiC synthesis but facilitated SiC synthesis. The Ti3SiC2/TiC−SiC composite had better oxidation resistance when SiC added quantity reached 20% but poorer oxidation resistance with SiC addition under 15%than Ti3SiC2/TiC composite at higher temperatures. There were more than half of the original SiC and a few Ti3SiC2 remaining in Ti3SiC2/TiC−SiC with 20% SiC addition, but all constituents in Ti3Si2/TiC composite were oxidized after 12 h in air at 1500 °C. The oxidation scale thickness of TS30, 1505.78μm, was near a half of that of T, 2715μm, at 1500 °C for 20 h. Ti3SiC2/TiC composite had a flexural strength of 474 MPa, which was surpassed by Ti3SiC2/TiC−SiC composites when SiC added amount reached 15%. The strength reached the peak of 518 MPa at 20%SiC added amount.

  4. RF rectifiers for EM power harvesting in a Deep Brain Stimulating device.

    Science.gov (United States)

    Hosain, Md Kamal; Kouzani, Abbas Z; Tye, Susannah; Kaynak, Akif; Berk, Michael

    2015-03-01

    A passive deep brain stimulation (DBS) device can be equipped with a rectenna, consisting of an antenna and a rectifier, to harvest energy from electromagnetic fields for its operation. This paper presents optimization of radio frequency rectifier circuits for wireless energy harvesting in a passive head-mountable DBS device. The aim is to achieve a compact size, high conversion efficiency, and high output voltage rectifier. Four different rectifiers based on the Delon doubler, Greinacher voltage tripler, Delon voltage quadrupler, and 2-stage charge pumped architectures are designed, simulated, fabricated, and evaluated. The design and simulation are conducted using Agilent Genesys at operating frequency of 915 MHz. A dielectric substrate of FR-4 with thickness of 1.6 mm, and surface mount devices (SMD) components are used to fabricate the designed rectifiers. The performance of the fabricated rectifiers is evaluated using a 915 MHz radio frequency (RF) energy source. The maximum measured conversion efficiency of the Delon doubler, Greinacher tripler, Delon quadrupler, and 2-stage charge pumped rectifiers are 78, 75, 73, and 76 % at -5 dBm input power and for load resistances of 5-15 kΩ. The conversion efficiency of the rectifiers decreases significantly with the increase in the input power level. The Delon doubler rectifier provides the highest efficiency at both -5 and 5 dBm input power levels, whereas the Delon quadrupler rectifier gives the lowest efficiency for the same inputs. By considering both efficiency and DC output voltage, the charge pump rectifier outperforms the other three rectifiers. Accordingly, the optimised 2-stage charge pumped rectifier is used together with an antenna to harvest energy in our DBS device.

  5. Optimal position of the transmitter coil for wireless power transfer to the implantable device.

    Science.gov (United States)

    Jinghui Jian; Stanaćević, Milutin

    2014-01-01

    The maximum deliverable power through inductive link to the implantable device is limited by the tissue exposure to the electromagnetic field radiation. By moving away the transmitter coil from the body, the maximum deliverable power is increased as the magnitude of the electrical field at the interface with the body is kept constant. We demonstrate that the optimal distance between the transmitter coil and the body is on the order of 1 cm when the current of the transmitter coil is limited to 1 A. We also confirm that the conditions on the optimal frequency of the power transmission and the topology of the transmission coil remain the same as if the coil was directly adjacent to the body.

  6. Controlled power delivery for super-resolution imaging of biological samples using digital micromirror device

    Science.gov (United States)

    Valiya Peedikakkal, Liyana; Cadby, Ashley

    2017-02-01

    Localization based super resolution images of a biological sample is generally achieved by using high power laser illumination with long exposure time which unfortunately increases photo-toxicity of a sample, making super resolution microscopy, in general, incompatible with live cell imaging. Furthermore, the limitation of photobleaching reduces the ability to acquire time lapse images of live biological cells using fluorescence microscopy. Digital Light Processing (DLP) technology can deliver light at grey scale levels by flickering digital micromirrors at around 290 Hz enabling highly controlled power delivery to samples. In this work, Digital Micromirror Device (DMD) is implemented in an inverse Schiefspiegler telescope setup to control the power and pattern of illumination for super resolution microscopy. We can achieve spatial and temporal patterning of illumination by controlling the DMD pixel by pixel. The DMD allows us to control the power and spatial extent of the laser illumination. We have used this to show that we can reduce the power delivered to the sample to allow for longer time imaging in one area while achieving sub-diffraction STORM imaging in another using higher power densities.

  7. Effectiveness of MnemoPow (Mnemonics Power Device in Teaching Limit Theorems of Calculus

    Directory of Open Access Journals (Sweden)

    Aldrin John J. Estonanto

    2017-11-01

    Full Text Available Calculus is oftentimes avoided by most students due to the common notion of its difficulty as a subject. Likewise, some studies revealed that most students find the topics in this subject very abstract to understand. To address these problems, a mnemonic device called MnemoPow (Mnemonics Power was developed. A quasi- experimental study was conducted in the laboratory high school of one state college in Sorsogon City to evaluate the effectiveness of the proposed mnemonic device. Two classes composed of forty- five (n= 45 students each were involved in this study as controlled and experimental group. The controlled group was introduced to Limit Theorems of Calculus using traditional lecture method while the experimental group was exposed to MnemoPow Device. Results of Pretest and Posttest were tested using t- test at 0. 05 level. Findings revealed that there is a significant difference between the performance of both groups. MnemoPow Device was found to be an effective approach in teaching Limit Theorems in Calculus.

  8. An efficient enzyme-powered micromotor device fabricated by cyclic alternate hybridization assembly for DNA detection.

    Science.gov (United States)

    Fu, Shizhe; Zhang, Xueqing; Xie, Yuzhe; Wu, Jie; Ju, Huangxian

    2017-07-06

    An efficient enzyme-powered micromotor device was fabricated by assembling multiple layers of catalase on the inner surface of a poly(3,4-ethylenedioxythiophene and sodium 4-styrenesulfonate)/Au microtube (PEDOT-PSS/Au). The catalase assembly was achieved by programmed DNA hybridization, which was performed by immobilizing a designed sandwich DNA structure as the sensing unit on the PEDOT-PSS/Au, and then alternately hybridizing with two assisting DNA to bind the enzyme for efficient motor motion. The micromotor device showed unique features of good reproducibility, stability and motion performance. Under optimal conditions, it showed a speed of 420 μm s -1 in 2% H 2 O 2 and even 51 μm s -1 in 0.25% H 2 O 2 . In the presence of target DNA, the sensing unit hybridized with target DNA to release the multi-layer DNA as well as the multi-catalase, resulting in a decrease of the motion speed. By using the speed as a signal, the micromotor device could detect DNA from 10 nM to 1 μM. The proposed micromotor device along with the cyclic alternate DNA hybridization assembly technique provided a new path to fabricate efficient and versatile micromotors, which would be an exceptional tool for rapid and simple detection of biomolecules.

  9. Laser processing for bevel termination of high voltage pn junction in SiC

    International Nuclear Information System (INIS)

    Kubiak, A; Ruta, Ł; Rosowski, A; French, P

    2016-01-01

    Proper edge termination of the p-n junction in silicon carbide is a key requirement in the fabrication of discrete devices able to withstand high voltages in reverse polarization. Due to the hardness of SiC the creation of the bevel termination remains difficult using mechanical machining. The use of laser beam sources with medium wavelength (532 nm) gives new possibilities in the machining of the silicon carbide. The paper presents the fabrication of the bevel termination structure in SiC using a green DPSS laser equipped with scanner and dedicated rotating sample holder. Characterization of the resulting structures proves the high potential of the proposed approach. (paper)

  10. Realizing stable fully spin polarized transport in SiC nanoribbons with dopant

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Xixi; Wang, Xianlong; Zheng, Xiaohong, E-mail: xhzheng@theory.issp.ac.cn; Zeng, Zhi [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); University of Science and Technology of China, Hefei 230026 (China); Hao, Hua [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2016-06-06

    Intrinsic half-metallicity recently reported in zigzag edged SiC nanoribbons is basically undetectable due to negligible energy difference between the antiferromagnetic (AFM) and ferromagnetic (FM) configurations. In this Letter, by density functional theory calculations, we demonstrate a scheme of N doping at the carbon edge to selectively close the edge state channel at this edge and achieve 100% spin filtering, no matter whether it is in an AFM state or FM state. This turns SiC nanoribbon into a promising material for obtaining stable and completely spin polarized transport and may find application in spintronic devices.

  11. Dense transient pinches and pulsed power technology: research and applications using medium and small devices

    International Nuclear Information System (INIS)

    Soto, Leopoldo; Pavez, Cristian; Moreno, Jose; Cardenas, Miguel; Zambra, Marcelo; Tarifeno, Ariel; Huerta, Luis; Tenreiro, Claudio; Giordano, Jose Luis; Lagos, Miguel; Escobar, Rodrigo; Ramos, Jorge; Altamirano, Luis; Retamal, Cesar; Silva, Patricio

    2008-01-01

    The Plasma Physics and Plasma Technology Group of the Chilean Nuclear Energy Commission (CCHEN) has, since about ten years ago, used plasma production devices to study dense hot plasmas, particularly Z-pinches and plasma foci (PFs). In the case of Z-pinches, the studies include studies on the dynamics and stability of gas-embedded Z-pinches at currents of thermonuclear interest, and preliminary studies on wire arrays. For PF research, the aim of the work has been to characterize the physics of these plasmas and also to carry out the design and construction of smaller devices-in terms of both input energy and size-capable of providing dense hot plasmas. In addition, taking advantage of the experience in pulsed power technology obtained from experimental researches in dense transient plasmas, an exploratory line of pulsed power applications is being developed. In this paper, a brief review listing the most important results achieved by the Plasma Physics and Plasma Technology Group of the CCHEN is presented, including the scaling studies, PF miniaturization and diagnostics and research on Z-pinches at currents of thermonuclear interest. Then, exploratory applications of pulsed power are presented, including nanoflashes of radiation for radiography and substances detection, high pulsed magnetic fields generation and rock fragmentation.

  12. Adapting cognitive radio technology for low-power wireless personal area network devices

    DEFF Research Database (Denmark)

    Toftegaard, Thomas Skjødeberg; Rohde, John

    2011-01-01

    The application of wireless personal area network (WPAN) and simple point-to-point wireless communication devices has increased drastically both in private household and in our workspaces in general over the last decade. Combined with the fact that the total number of wireless devices...... and associated standards present in the wireless environment is experiencing an extreme growth, the frequency spectrum scarcity is exposed as a severe challenge. Setting up efficient and reliable wireless WPAN links can be challenging even today. This is especially true because of the intensive use...... discusses the challenges associated with the implementation of highly reliable low-power WPAN networks for the future and the adaption of Cognitive Radio technology as a potential solution. A brief status on the maturity of CR technology will be presented as an integral part of this discussion....

  13. Semiconductor laser engineering, reliability and diagnostics a practical approach to high power and single mode devices

    CERN Document Server

    Epperlein, Peter W

    2013-01-01

    This reference book provides a fully integrated novel approach to the development of high-power, single-transverse mode, edge-emitting diode lasers by addressing the complementary topics of device engineering, reliability engineering and device diagnostics in the same book, and thus closes the gap in the current book literature. Diode laser fundamentals are discussed, followed by an elaborate discussion of problem-oriented design guidelines and techniques, and by a systematic treatment of the origins of laser degradation and a thorough exploration of the engineering means to enhance the optical strength of the laser. Stability criteria of critical laser characteristics and key laser robustness factors are discussed along with clear design considerations in the context of reliability engineering approaches and models, and typical programs for reliability tests and laser product qualifications. Novel, advanced diagnostic methods are reviewed to discuss, for the first time in detail in book literature, performa...

  14. Assessing electronic cigarette effects and regulatory impact: Challenges with user self-reported device power.

    Science.gov (United States)

    Rudy, Alyssa K; Leventhal, Adam M; Goldenson, Nicholas I; Eissenberg, Thomas

    2017-10-01

    Electronic cigarettes (ECIGs) aerosolize liquids for user inhalation that usually contain nicotine. ECIG nicotine emission is determined, in part, by user behavior, liquid nicotine concentration, and electrical power. Whether users are able to report accurately nicotine concentration and device electrical power has not been evaluated. This study's purpose was to examine if ECIG users could provide data relevant to understanding ECIG nicotine emission, particularly liquid nicotine concentration (mg/ml) as well as battery voltage (V) and heater resistance (ohms, Ω) - needed to calculate power (watts, W). Adult ECIG users (N=165) were recruited from Los Angeles, CA for research studies examining the effects of ECIG use. We asked all participants who visited the laboratory to report liquid nicotine concentration, V, and Ω. Liquid nicotine concentration was reported by 89.7% (mean=9.5mg/ml, SD=7.3), and responses were consistent with the distribution of liquids available in commonly marketed products. The majority could not report voltage (51.5%) or resistance (63.6%). Of the 40 participants (24.8%) who reported voltage and resistance, there was a substantial power range (2.2-32,670W) the upper limit of which exceeds that of the highest ECIG reported by any user to our knowledge (i.e., 2512W). If 2512W is taken as the upper limit, only 30 (18.2%) reported valid results (mean 237.3W, SD=370.6; range=2.2-1705.3W). Laboratory, survey, and other researchers interested in understanding ECIG effects to inform users and policymakers may need to use methods other than user self-report to obtain information regarding device power. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Effects of silicon carbide MOSFETs on the efficiency and power quality of a microgrid-connected inverter

    International Nuclear Information System (INIS)

    Ding, Xiaofeng; Chen, Feida; Du, Min; Guo, Hong; Ren, Suping

    2017-01-01

    Highlights: •The characteristics comparison between SiC-inverter and Si-inverter is implemented, considering thermal effects. •The voltage distortion of inverters is modeling from the perspective of the behaviors of the device. •The efficiency of the microgrid-connected inverter has been greatly increased by replacing Si with SiC. •The SiC microgrid-connected inverter has smaller voltage distortion and less harmonic current than those of Si-inverter. •The proposed analytical model has been validated by the experimental test. -- Abstract: With the expanding power demands and increasing use of renewable energy resources, microgrids have been widely supported. Wide bandgap semiconductor devices with higher blocking voltage capabilities and higher switching speeds, such as silicon carbide (SiC) devices, will become a critical component in building microgrids. This paper describes a comprehensive investigation of the effects of SiC Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs) on the efficiency and power quality of the inverters used in low voltage microgrids compared with conventional inverters based on silicon (Si) Insulated-gate Bipolar Transistors (IGBTs). First, the characteristics of both SiC and Si are measured by a double pulse test (DPT), considering thermal effects. Then, conduction and switching losses under different temperatures are calculated based on DPT results. Second, phase voltage distortions are modeled and calculated according to the tested switching and conduction characteristics of SiC, resulting in harmonic components in the phase current. Finally, an experiment is implemented. The experimental results show that the SiC-inverter greatly increases the energy efficiency and improves the power quality in the microgrid; these results are consistent with the analytical results.

  16. Neutron displacement damage cross sections for SiC

    International Nuclear Information System (INIS)

    Huang Hanchen; Ghoniem, N.

    1993-01-01

    Calculations of neutron displacement damage cross sections for SiC are presented. We use Biersack and Haggmark's empirical formula in constructing the electronic stopping power, which combines Lindhard's model at low PKA energies and Bethe-Bloch's model at high PKA energies. The electronic stopping power for polyatomic materials is computed on the basis of Bragg's Additivity Rule. A continuous form of the inverse power law potential is used for nuclear scattering. Coupled integro-differential equations for the number of displaced atoms j, caused by PKA i, are then derived. The procedure outlined above gives partial displacement cross sections, displacement cross sections for each specie of the lattice, and for each PKA type. The corresponding damage rates for several fusion and fission neutron spectra are calculated. The stoichiometry of the irradiated material is investigated by finding the ratio of displacements among various atomic species. The role of each specie in displacing atoms is also investigated by calculating the fraction of displacements caused by each PKA type. The study shows that neutron displacement damage rates of SiC in typical magnetic fusion reactor first walls will be ∝10-15 dpa MW -1 m 2 ; in typical lead-protected inertial confinement fusion reactor first walls they will be ∝15-20 dpa MW -1 m 2 . For fission spectra, we find that the neutron displacement damage rate of SiC is ∝74 dpa per 10 27 n/m 2 in FFTF, ∝39 dpa per 10 27 n/m 2 in HFIR, and 25 dpa per 10 27 n/m 2 in NRU. Approximately 80% of displacement atoms are shown to be of the carbon-type. (orig.)

  17. Blow-off device for limiting excess pressure in nuclear power plants, especially in boiling water nuclear power plants

    International Nuclear Information System (INIS)

    Simon, U.; Werner, K.D.; Hoffmann, D.; Pontani, B.

    1979-01-01

    In a blow-off device for limiting excess pressure in nuclear power plants, at least one condensation tube disposed so that a lower outflow and thereof is immersed in a volume of water, and an upper inflow end of the condensation tube extends out of the volume of water and is connectible to a source of steam that is to be condensed or a steam-air mixture, the outflow end of the condensation tube, for stabilizing the condensation being provided with an assembly of wall parts forming passageways extending in axial direction for subdividing the steam flow and bubbles produced in the volume of water, the passageways of the assembly of wall parts being stepped in axial direction at both axial ends of the assembly of wall parts

  18. Growth of graphene from SiC{0001} surfaces and its mechanisms

    International Nuclear Information System (INIS)

    Norimatsu, Wataru; Kusunoki, Michiko

    2014-01-01

    Graphene, a one-atom-layer carbon material, can be grown by thermal decomposition of SiC. On Si-terminated SiC(0001), graphene nucleates at steps and grows layer-by-layer, and as a result a homogeneous monolayer or bilayer can be obtained. We demonstrate this mechanism both experimentally and theoretically. On the C-face (000 1-bar ), multilayer graphene nucleates not only at steps, but also on the terraces. These differences reflect the distinct differences in the reactivity of these faces. Due to its high quality and structural controllability, graphene on SiC{0001} surfaces will be a platform for high-speed graphene device applications. (paper)

  19. Efficiency and Cost Comparison of Si IGBT and SiC JFET Isolated DC/DC Converters

    DEFF Research Database (Denmark)

    Nielsen, Rasmus Ørndrup; Török, Lajos; Munk-Nielsen, Stig

    2013-01-01

    Silicon carbide (SiC) and other wide band gap devices are in these years undergoing a rapid development. The need for higher efficiency and smaller dimensions are forcing engineers to take these new devices in to considerations when choosing semiconductors for their converters. In this article a Si...

  20. Powered bone marrow biopsy procedures produce larger core specimens, with less pain, in less time than with standard manual devices

    Directory of Open Access Journals (Sweden)

    Larry J. Miller

    2011-07-01

    Full Text Available Bone marrow sampling remains essential in the evaluation of hematopoietic and many non-hematopoietic disorders. One common limitation to these procedures is the discomfort experienced by patients. To address whether a Powered biopsy system could reduce discomfort while providing equivalent or better results, we performed a randomized trial in adult volunteers. Twenty-six subjects underwent bilateral biopsies with each device. Core samples were obtained in 66.7% of Manual insertions; 100% of Powered insertions (P=0.002. Initial mean biopsy core lengths were 11.1±4.5 mm for the Manual device; 17.0±6.8 mm for the Powered device (P<0.005. Pathology assessment for the Manual device showed a mean length of 6.1±5.6 mm, width of 1.0±0.7 mm, and volume of 11.0±10.8 mm3. Powered device measurements were mean length of 15.3±6.1 mm, width of 2.0±0.3 mm, and volume of 49.1±21.5 mm3 (P<0.001. The mean time to core ejection was 86 seconds for Manual device; 47 seconds for the Powered device (P<0.001. The mean second look overall pain score was 33.3 for the Manual device; 20.9 for the Powered (P=0.039. We conclude that the Powered biopsy device produces superior sized specimens, with less overall pain, in less time.