WorldWideScience

Sample records for circuit breakers

  1. Overriding Faulty Circuit Breakers

    Science.gov (United States)

    Robbins, Richard L.; Pierson, Thomas E.

    1987-01-01

    Retainer keeps power on in emergency. Simple mechanical device attaches to failed aircraft-type push/pull circuit breaker to restore electrical power temporarily until breaker replaced. Device holds push/pull button in closed position; unnecessary for crewmember to hold button in position by continual finger pressure. Sleeve and plug hold button in, overriding mechanical failure in circuit breaker. Windows in sleeve show button position.

  2. Latching overcurrent circuit breaker

    Science.gov (United States)

    Moore, M. L.

    1970-01-01

    Circuit breaker consists of a preset current amplitude sensor, and a lamp-photo-resistor combination in a feedback arrangement which energizes a power switching relay. The ac input power is removed from the load at predetermined current amplitudes.

  3. High temperature circuit breaker

    Science.gov (United States)

    Edwards, R. N.; Travis, E. F.

    1970-01-01

    Alternating current circuit breaker is suitable for reliable long-term service at 1000 deg F in the vacuum conditions of outer space. Construction materials are resistant to nuclear radiation and vacuum welding. Service test conditions and results are given.

  4. Commutation circuit for an HVDC circuit breaker

    Science.gov (United States)

    Premerlani, William J.

    1981-01-01

    A commutation circuit for a high voltage DC circuit breaker incorporates a resistor capacitor combination and a charging circuit connected to the main breaker, such that a commutating capacitor is discharged in opposition to the load current to force the current in an arc after breaker opening to zero to facilitate arc interruption. In a particular embodiment, a normally open commutating circuit is connected across the contacts of a main DC circuit breaker to absorb the inductive system energy trapped by breaker opening and to limit recovery voltages to a level tolerable by the commutating circuit components.

  5. 46 CFR 169.670 - Circuit breakers.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Circuit breakers. 169.670 Section 169.670 Shipping COAST... Gross Tons § 169.670 Circuit breakers. Each circuit breaker must be of the manually reset type designed... the circuit without damage to the circuit breaker....

  6. 46 CFR 111.54-1 - Circuit breakers.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Circuit breakers. 111.54-1 Section 111.54-1 Shipping... REQUIREMENTS Circuit Breakers § 111.54-1 Circuit breakers. (a) Each Circuit breaker must— (1) Meet the general... circuit breaker frame. (e) Each circuit breaker located in an engineroom, boilerroom, or machinery......

  7. Solid-State dc Circuit Breaker

    Science.gov (United States)

    Harvey, P.

    1983-01-01

    Circuit breaker with no moving parts protects direct-current (dc) loads. Current which circuit breaker opens (trip current) is adjustable and so is time delay before breaker trips. Forward voltage drop rises from 0.6 to 1.2 V as current rises to trip point. Breaker has two terminals, like fuse, therefore replaces fuse in dc circuit. Powered by circuit it protects and reset by either turning off power source or disconnecting load.

  8. High Speed Solid State Circuit Breaker

    Science.gov (United States)

    Podlesak, Thomas F.

    1993-01-01

    The U.S. Army Research Laboratory, Fort Monmouth, NJ, has developed and is installing two 3.3 MW high speed solid state circuit breakers at the Army's Pulse Power Center. These circuit breakers will interrupt 4160V three phase power mains in no more than 300 microseconds, two orders of magnitude faster than conventional mechanical contact type circuit breakers. These circuit breakers utilize Gate Turnoff Thyristors (GTO's) and are currently utility type devices using air cooling in an air conditioned enclosure. Future refinements include liquid cooling, either water or two phase organic coolant, and more advanced semiconductors. Each of these refinements promises a more compact, more reliable unit.

  9. Apollo 14 mission circuit breaker anomaly

    Science.gov (United States)

    1971-01-01

    Continuity through the circuit breaker in the mechanically closed condition was prevented by a foreign substance on the contact surface onboard Apollo 14. It was concluded that this was the only failure of this type in over 3400 units that were flown, and since no circuit breaker is a single-point failure for crew safety or mission success, no corrective action was taken.

  10. 30 CFR 77.904 - Identification of circuit breakers.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Identification of circuit breakers. 77.904... COAL MINES Low- and Medium-Voltage Alternating Current Circuits § 77.904 Identification of circuit breakers. Circuit breakers shall be labeled to show which circuits they control unless identification...

  11. 30 CFR 75.900-1 - Circuit breakers; location.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuit breakers; location. 75.900-1 Section 75... Alternating Current Circuits § 75.900-1 Circuit breakers; location. Circuit breakers used to protect low-and medium-voltage circuits underground shall be located in areas which are accessible for...

  12. 30 CFR 75.904 - Identification of circuit breakers.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Identification of circuit breakers. 75.904 Section 75.904 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... Alternating Current Circuits § 75.904 Identification of circuit breakers. Circuit breakers shall be marked...

  13. 30 CFR 75.800-1 - Circuit breakers; location.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuit breakers; location. 75.800-1 Section 75.800-1 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY... § 75.800-1 Circuit breakers; location. Circuit breakers protecting high-voltage circuits entering...

  14. Trends of Development of Interruption Technologies in DC Circuit Breaker

    Energy Technology Data Exchange (ETDEWEB)

    Lee, B.Y.; Chung, J.K.; Shin, Y.J.; Park, K.Y. [Korea Electrotechnology Research Institute (Korea)

    1999-05-01

    This paper describes the necessity and the history of the development of DC circuit breaker and the trends of the development of interruption technologies in DC circuit breaker. (author). 8 refs., 3 figs., 3 tabs.

  15. 30 CFR 75.800 - High-voltage circuits; circuit breakers.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage circuits; circuit breakers. 75.800... § 75.800 High-voltage circuits; circuit breakers. High-voltage circuits entering the underground area of any coal mine shall be protected by suitable circuit breakers of adequate interrupting...

  16. 30 CFR 75.601-1 - Short circuit protection; ratings and settings of circuit breakers.

    Science.gov (United States)

    2010-07-01

    ... of circuit breakers. 75.601-1 Section 75.601-1 Mineral Resources MINE SAFETY AND HEALTH... Trailing Cables § 75.601-1 Short circuit protection; ratings and settings of circuit breakers. Circuit breakers providing short circuit protection for trailing cables shall be set so as not to exceed...

  17. Circuit Breakers and Market Runs

    OpenAIRE

    Sarah Draus; Mark Van Achter

    2012-01-01

    This paper analyzes whether the application of a “circuit breaker” to a financial market (i.e. a mechanism that interrupts trading for a predetermined period when the price moves beyond a predetermined level) reaches its intended goals of increased market stability and overall welfare. Our framework of analysis is a model in which investors can trade at several dates and might face a liquidity shock forcing them to sell immediately when the shock occurs. This setting potentially induces a “ma...

  18. Low Insertion HVDC Circuit Breaker: Magnetically Pulsed Hybrid Breaker for HVDC Power Distribution Protection

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-01-09

    GENI Project: General Atomics is developing a direct current (DC) circuit breaker that could protect the grid from faults 100 times faster than its alternating current (AC) counterparts. Circuit breakers are critical elements in any electrical system. At the grid level, their main function is to isolate parts of the grid where a fault has occurred—such as a downed power line or a transformer explosion—from the rest of the system. DC circuit breakers must interrupt the system during a fault much faster than AC circuit breakers to prevent possible damage to cables, converters and other grid-level components. General Atomics’ high-voltage DC circuit breaker would react in less than 1/1,000th of a second to interrupt current during a fault, preventing potential hazards to people and equipment.

  19. 30 CFR 75.900-3 - Testing, examination, and maintenance of circuit breakers; procedures.

    Science.gov (United States)

    2010-07-01

    ... circuit breakers; procedures. 75.900-3 Section 75.900-3 Mineral Resources MINE SAFETY AND HEALTH... maintenance of circuit breakers; procedures. Circuit breakers protecting low- and medium-voltage alternating... such tests, actuating any of the circuit breaker auxiliaries or control circuits in any manner...

  20. Synchronous transmission circuit breaker development. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Garzon, R D

    1976-08-01

    The need for the development of a synchronous transmission breaker is discussed and the basic preliminary specifications for such a circuit breaker are established and tabulated. The initial exploratory work designed to establish the preferred designs for a synchronous pulse generator, (or current zero predictor), for an operating mechanism and for a suitable interrupter are described in detail. The experimental results obtained with vacuum interrupters and with axial blast interrupters using pure SF/sub 6/, mixtures of SF/sub 6/ and N/sub 2/, and high pressure liquid SF/sub 6/ are reported. The results are then evaluated and the performances obtained with each interrupting media are compared arriving at the end to a choice of a preferred design. This preferred design, an interrupter that uses SF/sub 6/ in the liquid state at pressures of 13.8 megapascals (2000 psi), is completely described. The results obtained in a series of experiments designed to establish limits of performance for this interrupter are also discussed.

  1. 30 CFR 77.800 - High-voltage circuits; circuit breakers.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false High-voltage circuits; circuit breakers. 77.800... COAL MINES Surface High-Voltage Distribution § 77.800 High-voltage circuits; circuit breakers. High-voltage circuits supplying power to portable or mobile equipment shall be protected by suitable...

  2. 30 CFR 77.800-1 - Testing, examination, and maintenance of circuit breakers; procedures.

    Science.gov (United States)

    2010-07-01

    ... circuit breakers; procedures. 77.800-1 Section 77.800-1 Mineral Resources MINE SAFETY AND HEALTH..., examination, and maintenance of circuit breakers; procedures. (a) Circuit breakers and their auxiliary devices... circuit breaker and its auxiliary devices, and such repairs or adjustments as are indicated by such...

  3. 30 CFR 77.900-1 - Testing, examination, and maintenance of circuit breakers; procedures.

    Science.gov (United States)

    2010-07-01

    ... circuit breakers; procedures. 77.900-1 Section 77.900-1 Mineral Resources MINE SAFETY AND HEALTH... § 77.900-1 Testing, examination, and maintenance of circuit breakers; procedures. Circuit breakers... qualified as provided in § 77.103. In performing such tests, the circuit breaker auxiliaries or...

  4. Transient Ablation Regime in Circuit Breakers

    Institute of Scientific and Technical Information of China (English)

    Alexandre MARTIN; Jean-Yves TREPANIER; Marcelo REGGIO; GUO Xue-yan

    2007-01-01

    Nozzle wall ablation caused by high temperature electric arcs is studied in the context of high voltage SF6 circuit breakers.The simplified ablation model used in litterature has been updated to take into account the unsteady state of ablation.Ablation rate and velocity are now calculated by a kinetic model using two layers of transition,between the bulk plasma and the ablating wall.The first layer (Knudsen layer),right by the wall,is a kinetic layer of a few mean-free path of thickness.The second layer is collision dominated and makes the transition between the kinetic layer and the plasma bulk.With this new coupled algorithm,it is now possible to calculate the temperature distribution inside the wall,as well as more accurate ablation rates.

  5. Hybrid HVDC circuit breaker with self-powered gate drives

    OpenAIRE

    Effah, Francis Boafo; Watson, Alan James; Ji, Chao; Amankwah, Emmanuel K.; Johnson, Christopher Mark; Davidson, Colin; Clare, Jon C.

    2016-01-01

    The ever increasing electric power demand and the advent of renewable energy sources have revived the interest in high-voltage direct current (HVDC) multi-terminal networks. However, the absence of a suitable circuit breaker or fault tolerant VSC station topologies with the required characteristics (such as operating speed) have, until recently, been an obstacle in the development of large scale multi-terminal networks for HVDC. This paper presents a hybrid HVDC circuit breaker concept which...

  6. Hybrid HVDC circuit breaker with self-powered gate drives

    OpenAIRE

    Effah, Francis Boafo; Watson, Alan James; Ji, Chao; Amankwah, Emmanuel K.; Johnson, Christopher Mark; Davidson, Colin; Clare, Jon C.

    2016-01-01

    The ever increasing electric power demand and the advent of renewable energy sources have revived the interest in high-voltage direct current (HVDC) multi-terminal networks. However, the absence of a suitable circuit breaker or fault tolerant VSC station topologies with the required characteristics (such as operating speed) have, until recently, been an obstacle in the development of large scale multi-terminal networks for HVDC. This paper presents a hybrid HVDC circuit breaker concept which ...

  7. Programmable Low-Voltage Circuit Breaker and Tester

    Science.gov (United States)

    Greenfield, Terry

    2008-01-01

    An instrumentation system that would comprise a remotely controllable and programmable low-voltage circuit breaker plus several electric-circuit-testing subsystems has been conceived, originally for use aboard a spacecraft during all phases of operation from pre-launch testing through launch, ascent, orbit, descent, and landing. The system could also be adapted to similar use aboard aircraft. In comparison with remotely controllable circuit breakers heretofore commercially available, this system would be smaller, less massive, and capable of performing more functions, as needed for aerospace applications.

  8. 30 CFR 75.800-4 - Testing, examination, and maintenance of circuit breakers; record.

    Science.gov (United States)

    2010-07-01

    ... circuit breakers; record. 75.800-4 Section 75.800-4 Mineral Resources MINE SAFETY AND HEALTH... Underground High-Voltage Distribution § 75.800-4 Testing, examination, and maintenance of circuit breakers... adjustment of all circuit breakers protecting high-voltage circuits which enter any underground area of...

  9. 30 CFR 75.800-3 - Testing, examination and maintenance of circuit breakers; procedures.

    Science.gov (United States)

    2010-07-01

    ... High-Voltage Distribution § 75.800-3 Testing, examination and maintenance of circuit breakers; procedures. (a) Circuit breakers and their auxiliary devices protecting underground high-voltage circuits... shall include visual observation of all components of the circuit breaker and its auxiliary devices,...

  10. 30 CFR 77.800-2 - Testing, examination, and maintenance of circuit breakers; record.

    Science.gov (United States)

    2010-07-01

    ... circuit breakers; record. 77.800-2 Section 77.800-2 Mineral Resources MINE SAFETY AND HEALTH..., examination, and maintenance of circuit breakers; record. The operator shall maintain a written record of each test, examination, repair, or adjustment of all circuit breakers protecting high-voltage circuits....

  11. 30 CFR 75.900-4 - Testing, examination, and maintenance of circuit breakers; record.

    Science.gov (United States)

    2010-07-01

    ... circuit breakers; record. 75.900-4 Section 75.900-4 Mineral Resources MINE SAFETY AND HEALTH... maintenance of circuit breakers; record. The operator of any coal mine shall maintain a written record of each test, examination, repair, or adjustment of all circuit breakers protecting low- and...

  12. 30 CFR 75.809 - Identification of circuit breakers and disconnecting switches.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Identification of circuit breakers and... High-Voltage Distribution § 75.809 Identification of circuit breakers and disconnecting switches. Circuit breakers and disconnecting switches underground shall be marked for identification....

  13. 30 CFR 77.809 - Identification of circuit breakers and disconnecting switches.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Identification of circuit breakers and disconnecting switches. 77.809 Section 77.809 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... circuit breakers and disconnecting switches. Circuit breakers and disconnecting switches shall be...

  14. 48 CFR 252.225-7038 - Restriction on Acquisition of Air Circuit Breakers.

    Science.gov (United States)

    2010-10-01

    ... of Air Circuit Breakers. 252.225-7038 Section 252.225-7038 Federal Acquisition Regulations System... Circuit Breakers. As prescribed in 225.7006-4(b), use the following clause: Restriction on Acquisition of Air Circuit Breakers (JUN 2005) Unless otherwise specified in its offer, the Contractor shall...

  15. 48 CFR 252.225-7037 - Evaluation of Offers for Air Circuit Breakers.

    Science.gov (United States)

    2010-10-01

    ... Air Circuit Breakers. 252.225-7037 Section 252.225-7037 Federal Acquisition Regulations System DEFENSE... CLAUSES Text of Provisions And Clauses 252.225-7037 Evaluation of Offers for Air Circuit Breakers. As prescribed in 225.7006-4(a), use the following provision: Evaluation of Offers for Air Circuit Breakers...

  16. 46 CFR 111.30-4 - Circuit breakers removable from the front.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Circuit breakers removable from the front. 111.30-4... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Switchboards § 111.30-4 Circuit breakers removable from the front. Circuit breakers, when installed on generator or distribution switchboards, must be mounted or arranged...

  17. Remote control circuit breaker evaluation testing. [for space shuttles

    Science.gov (United States)

    Bemko, L. M.

    1974-01-01

    Engineering evaluation tests were performed on several models/types of remote control circuit breakers marketed in an attempt to gain some insight into their potential suitability for use on the space shuttle vehicle. Tests included the measurement of several electrical and operational performance parameters under laboratory ambient, space simulation, acceleration and vibration environmental conditions.

  18. Switching Surge Analysis of Vacuum Circuit Breaker using EMTP

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ik Mo; Kim, Ji Hong [Hyundai Heavy Industry, Mechatronics Research Institute (Korea)

    2000-07-01

    The first objective of this study is to set up the switching surge analysis method in motor driving distribution system. The simplified model which can simulate the motor energization and circuit breaker re-ignitions, and each circuit element model is presented in this paper. The second objective is to calculate the quantity of surge over-voltage in real nuclear power station. And the surge suppressing measures are verified on the simulation basis. It is clarified that most cases are not satisfactory to meet the IEEE standard 522-1992 without using surge suppressing measures. In cases that the surge arrester are installed in distribution board at the load side of circuit breaker. The IEEE specification is fully met. (author). 6 refs., 4 figs., 3 tabs.

  19. Assessment and modelling of switching technologies for application in HVDC-circuit breakers

    OpenAIRE

    Lund, Johan

    2011-01-01

    A key element for future DC-grids is a DC circuit breaker that in case of a short circuit fault reliably can turn off a short circuit current. AC circuit breakers are well known components that has been in use for a long time in AC-grids. The AC circuit breaker is designed to interrupt the current at its natural current zero crossings. In DC grids such does not exists, therefore AC breakers can not be directly applied in DC grids. Different concepts and technologies to solve this problem is a...

  20. An Overview of Dynamic Contact Resistance Measurement of HV Circuit Breakers

    Science.gov (United States)

    Bhole, A. A.; Gandhare, W. Z.

    2016-06-01

    With the deregulation of the electrical power industry, utilities and service companies are operating in a changing business environment. High voltage circuit breakers are extremely important for the function of modern electric power supply systems. The need to predict the proper function of circuit breaker grew over the years as the transmission networks expanded. The maintenance of circuit breakers deserves special consideration because of their importance for routine switching and for protection of other equipments. Electric transmission system breakups and equipment destruction can occur if a circuit breaker fails to operate because of a lack of preventive maintenance. Dynamic Contact Resistance Measurement (DCRM) is known as an effective technique for assessing the condition of power circuit breakers contacts and operating mechanism. This paper gives a general review about DCRM. It discusses the practical case studies on use of DCRM for condition assessment of high voltage circuit breakers.

  1. Calculation and comparison of circuit breaker parameters in Power World Simulator

    Directory of Open Access Journals (Sweden)

    Kuljinder Kaur,

    2016-01-01

    Full Text Available A circuit breaker has ratings that an engineer uses for their application. These ratings define circuit breaker performance characteristics. A good understanding of Ratings allow the electrical engineer to make a proper comparison of various circuit breaker designs. In this research work, the different ratings of circuit breaker were calculated. The other objective of this work was comparison between ratings of existing circuit breaker and calculated ratings in POWER WORLD SIMULATOR. Further, the impact of time delay in circuit breaker was studied. These calculations were performed for rated current of 400 & 630 Amps. The results performed in POWER WORLD SIMULATOR were shown better and information gained from the analysis can be used for proper relay selection, settings, performances and coordination.

  2. Study on the instantaneous protection reliability of low voltage circuit breakers

    Institute of Scientific and Technical Information of China (English)

    LU Jian-guo; DU Tai-hang; LUO Yan-yan

    2007-01-01

    This paper outlines the significance of enhancing the instantaneous protection reliability of low voltage circuit breakers and describes their main failure modes. The instantaneous failure mechanism of low voltage circuit breakers was analyzed so that measures to improve instantaneous protection reliability can be determined. Furthermore, the theory of the instantaneous characteristics Calibration device for low voltage circuit breakers and the method of eliminating the non-periodic component of test current are given in detail. Finally, the test results are presented.

  3. Evaluation of Bidirectional Silicon Carbide Solid-State Circuit Breaker v3.2

    Science.gov (United States)

    2013-07-01

    Evaluation of Bidirectional Silicon Carbide Solid-State Circuit Breaker v3.2 by D. Urciuoli ARL-MR-0845 July 2013...Evaluation of Bidirectional Silicon Carbide Solid-State Circuit Breaker v3.2 D. Urciuoli Sensors and Electron Devices Directorate, ARL...2012 to 20 March 2013 4. TITLE AND SUBTITLE Evaluation of Bidirectional Silicon Carbide Solid-State Circuit Breaker v3.2 5a. CONTRACT NUMBER 5b

  4. 30 CFR 77.900-2 - Testing, examination, and maintenance of circuit breakers; record.

    Science.gov (United States)

    2010-07-01

    ... circuit breakers; record. 77.900-2 Section 77.900-2 Mineral Resources MINE SAFETY AND HEALTH... § 77.900-2 Testing, examination, and maintenance of circuit breakers; record. The operator shall maintain a written record of each test, examination, repair or adjustment of all circuit...

  5. Experimental and theoretical analysis of vacuum circuit breaker prestrike effect on a transformer

    NARCIS (Netherlands)

    Popov, M.; Smeets, R.P.P.; Van der Sluis, L.; De Herdt, H.; Declerq, J.

    2009-01-01

    The work presented in this paper deals with the investigation of circuit breaker prestrike effect that occurs during energizing a distribution transformer. An experimental test setup that consists of a supply transformer, a vacuum circuit breaker (VCB), a cable and a test transformer is built, and t

  6. Revision of TRV Requirements for the Application of Generator Circuit-Breakers

    NARCIS (Netherlands)

    Palazzo, M.; Popov, M.; Marmolejo, A.; Delfanti, M.

    2015-01-01

    The requirements imposed on generator circuitbreakers greatly differ from the requirements imposed on other transmission and distribution circuit-breakers. Due to the location of installation between the generator and the associated step-up transformer, a generator circuit-breaker must meet high tec

  7. 48 CFR 225.7006 - Restriction on air circuit breakers for naval vessels.

    Science.gov (United States)

    2010-10-01

    ... on air circuit breakers for naval vessels. ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Restriction on air circuit breakers for naval vessels. 225.7006 Section 225.7006 Federal Acquisition Regulations System...

  8. Fault current limiter with solid-state circuit breakers

    Science.gov (United States)

    Bălan, H.; Neamț, L.; Buzdugan, M. I.; Varodi, T.; Pop, E.

    2016-08-01

    Switching of power circuit breakers is an important technical issue, especially at short circuit, since the fault current cause thermal and dynamic stresses, and the power quality worsens. Recently, the development of distributed renewable electricity induces the short circuit protection problematic because the distributed production of electric energy cause the transport networks to lose their radial character and disturbs the protective relays coordination. The modern technologies for power switching uses static fault current limiters, which offers a viable solution to remove the problems caused by large fault currents in the system. An appropriate design of the current limiting device reduces the thermal and dynamic stress and limits the fault current to a low value. The static switches are based on high power semiconductor devices that offer advantages compared to mechanical switches. Using a fault current limiter that minimizes the effect of distributed generation of electricity in a radial network on the co-ordination of protective relays is a solution to this problem in terms of switching speed and lifespan of power switches.

  9. State Evaluation Method Based on Multiagent System for High Voltage Circuit Breaker's Mechanical Properties

    Institute of Scientific and Technical Information of China (English)

    LI Bin; LIN Xin; XU Jianyuan; QI Hongwei; ZHANG Bin

    2013-01-01

    To realize multi-signal joint diagnosis in circuit breaker's state evaluation methods,and to improve their evaluation accuracy,we proposed an intelligent evaluation model of circuit breaker mechanical properties based on multiagent system.Taking a circuit breaker which has mono-stable permanent magnetic operating mechanism as the example,its model involves four kinds of signals:auxiliary contact,operating mechanism current,travel of the contact,and mechanical vibration.Detailed analyses on the evaluation agent's architecture and the process of the system's multiagent evaluation and ratiocination were also proposed.Moreover,it is proved by three application cases that the proposed method could accurately evaluate circuit breaker status not only with normal signals,but also in certain signal failure situations; meanwhile the model has a strong self-learning ability.

  10. HV/EHV circuit breakers status monitoring using the CBW (circuit breaker watcher) system; Monitoramento do estado de disjuntores AT/EAT utilizando o sistema CBW (circuit breaker watcher)

    Energy Technology Data Exchange (ETDEWEB)

    Duran, Ricardo; Schwarz, Marcos Bernert [Schneider Electric Alta Tensao Ltda., Itajai, SC (Brazil)]. E-mail: ricardo.duran@vasat.com.br

    2001-07-01

    Taking in consideration the new requirements related with the imposed penalties to the electric sector due to energy supply interruption it is necessary to employ new maintenance techniques. In this direction, a solution is the introduction of digital systems in the substations supervision, facilitating by this way their operation. The introduction of these systems doesn't care if the substation is of the attended type or not. A system that supplies the monitoring of the HV/EHV circuit breaker status can be considered as an important support tool for new techniques of the maintenance in HV/EHV equipment. This document describes the CBW (Circuit Breaker Watcher) system destined to the monitoring of HV/EHV circuit breakers status, with the main objective to monitor the electric characteristics of power supply signals, commands and measurable magnitudes.The text also approaches integrated system through which it is possible to monitor, in a same system, circuit breakers, switchgears, transformers or others required equipment for monitoring.

  11. Biocompatible circuit-breaker chip for thermal management of biomedical microsystems

    Science.gov (United States)

    Luo, Yi; Dahmardeh, Masoud; Takahata, Kenichi

    2015-05-01

    This paper presents a thermoresponsive micro circuit breaker for biomedical applications specifically targeted at electronic intelligent implants. The circuit breaker is micromachined to have a shape-memory-alloy cantilever actuator as a normally closed temperature-sensitive switch to protect the device of interest from overheating, a critical safety feature for smart implants including those that are electrothermally driven with wireless micro heaters. The device is fabricated in a size of 1.5  ×  2.0  ×  0.46 mm3 using biocompatible materials and a chip-based titanium package, exhibiting a nominal cold-state resistance of 14 Ω. The breaker rapidly enters the full open condition when the chip temperature exceeds 63 °C, temporarily breaking the circuit of interest to lower its temperature until chip temperature drops to 51 °C, at which the breaker closes the circuit to allow current to flow through it again, physically limiting the maximum temperature of the circuit. This functionality is tested in combination with a wireless resonant heater powered by radio-frequency electromagnetic radiation, demonstrating self-regulation of heater temperature. The developed circuit-breaker chip operates in a fully passive manner that removes the need for active sensor and circuitry to achieve temperature regulation in a target device, contributing to the miniaturization of biomedical microsystems including electronic smart implants where thermal management is essential.

  12. INVESTIGATION OF MECHANICAL STRESSES IN THE DRIVE SHAFT OF MV VACUUM CIRCUIT BREAKER

    Directory of Open Access Journals (Sweden)

    E. I. Baida

    2017-03-01

    Full Text Available Introduction. In the last 10-15 years a dominant position in the market of medium voltage circuit breakers, vacuum circuit breakers have taken in which as an actuator mono- or bistable actuators with permanent magnets are used. Such circuit breakers are characterized by simplicity of design, high reliability, require preventive maintenance for many years. Development, research and improvement of vacuum circuit breakers are carried out at the Department for Electrical Apparatus, National Technical University «Kharkiv Polytechnic Institute». While working on the circuit breakers, developers have to deal with two related objectives – electrical and mechanical. This paper considers the solution of one of these problems – calculation of mechanical forces in the drive shaft of the vacuum circuit breaker in static and dynamic modes. This work was preceded by the failure of the results of measurements of the prototype circuit breakers’ contacts. Measurements have shown that these values do not match the expected values (there were less than the value of 0.8 to 1 mm. The assumption about the reasons for this discrepancy needed to be detailed checked. The results of the work done are presented in this paper. Purpose. Investigation of static and dynamic mechanical stresses and strains in the drive shaft of the vacuum circuit breaker mechanism to determine its characteristics and material selection. Methods. The investigation of mechanical processes is performed by the finite element method in the COMSOL software package. Results. We obtain the static and dynamic characteristics of the circuit breaker drive shaft: deformations, reaction forces, stresses. These characteristics made it possible to determine the actual course of the contacts, select shaft material and calculate the forces acting on the bearings. Conclusions. It is shown that the contact velocity and contact pressure are different from the theoretical value due to the deformation of the

  13. Vacuum Dielectric Recovery Characteristics of a Novel Current Limiting Circuit Breaker Base on Artificial Current Zero

    Institute of Scientific and Technical Information of China (English)

    JIANG Zhuangxian; ZHUANG Jinwu; WANG Chen; WU Jin; LIU Luhui

    2012-01-01

    A novel current limiting circuit breaker employs zero current switching method in cutting off DC current, which gives out a reverse impulsive current towards a high speed vacuum interrupter and force the current down to zero. This kind of breaker is simply in structure and can act in a very short time with high current limiting capability, and therefore it has a long electric life and is extremely suitable to be installed in a DC electrical system as a fault orotection utility.

  14. Research on current sharing of paralleled IGBTs in different DC breaker circuit topologies

    Directory of Open Access Journals (Sweden)

    Chen Ying

    2016-01-01

    Full Text Available IGBT modules used in series and parallel to satisfy the requirement in high-power DC circuit breakers are often prone to large-current destruction due to current unbalance between paralleled IGBTs. It is of great importance to identify the current unbalance causes and to find a method optimizing the current sharing of paralleled IGBTs. In this paper the current-sharing influencing factors are discussed and verified by simulation. Two possible circuit topologies used in DC circuit breakers are proposed and simulated to see their performance in current sharing. The results show that one of them can provide us with a simple and effective method to achieve good current balancing in the DC circuit breaker application.

  15. CFD Simulation of Transonic Flow in High-Voltage Circuit Breaker

    Directory of Open Access Journals (Sweden)

    Xiangyang Ye

    2012-01-01

    Full Text Available A high-voltage circuit breaker is an indispensable piece of equipment in the electric transmission and distribution systems. Transonic flow typically occurs inside breaking chamber during the current interruption, which determines the insulating characteristics of gas. Therefore, accurate compressible flow simulations are required to improve the prediction of the breakdown voltages in various test duties of high-voltage circuit breakers. In this work, investigation of the impact of the solvers on the prediction capability of the breakdown voltages in capacitive switching is presented. For this purpose, a number of compressible nozzle flow validation cases have been presented. The investigation is then further extended for a real high-voltage circuit breaker geometry. The correlation between the flow prediction accuracy and the breakdown voltage prediction capability is identified.

  16. Analysis of cold flow reestablishment time in a circuit breaker nozzle

    Science.gov (United States)

    Leone, S. A.; Nagamatsu, H. T.

    1983-01-01

    The deblocking process in a circuit breaker nozzle is similar to the flow starting process in a shock tunnel, and the computer uses this analogy to solve for the deblocking process by utilizing a diaphragm at the throat of a nozzle. At time equal to zero the diaphragm is broken and the throat area increases with time. It is a rarity to have the area as a function of both time and distance. Experimental data obtained from the RPI calibration shock tunnel are utilized to verify some of the calculated results with the area being a function of distance and the agreement is found to be good. The circuit breaker designer can utilize the computer simulation to estimate the deblocking time, an important parameter in the design of circuit breakers.

  17. Optimization of the Switch Mechanism in a Circuit Breaker Using MBD Based Simulation

    Directory of Open Access Journals (Sweden)

    Jin-Seok Jang

    2015-01-01

    Full Text Available A circuit breaker is widely used to protect electric power system from fault currents or system errors; in particular, the opening mechanism in a circuit breaker is important to protect current overflow in the electric system. In this paper, multibody dynamic model of a circuit breaker including switch mechanism was developed including the electromagnetic actuator system. Since the opening mechanism operates sequentially, optimization of the switch mechanism was carried out to improve the current breaking time. In the optimization process, design parameters were selected from length and shape of each latch, which changes pivot points of bearings to shorten the breaking time. To validate optimization results, computational results were compared to physical tests with a high speed camera. Opening time of the optimized mechanism was decreased by 2.3 ms, which was proved by experiments. Switch mechanism design process can be improved including contact-latch system by using this process.

  18. Approaching the Processes in the Generator Circuit Breaker at Disconnection through Sustainability Concepts

    Directory of Open Access Journals (Sweden)

    Carmen A. Bulucea

    2013-03-01

    Full Text Available Nowadays, the electric connection circuits of power plants (based on fossil fuels as well as renewable sources entail generator circuit-breakers (GCBs at the generator terminals, since the presence of that electric equipment offers many advantages related to the sustainability of a power plant. In an alternating current (a.c. circuit the interruption of a short circuit is performed by the circuit-breaker at the natural passing through zero of the short-circuit current. During the current interruption, an electric arc is generated between the opened contacts of the circuit-breaker. This arc must be cooled and extinguished in a controlled way. Since the synchronous generator stator can flow via highly asymmetrical short-circuit currents, the phenomena which occur in the case of short-circuit currents interruption determine the main stresses of the generator circuit-breaker; the current interruption requirements of a GCB are significantly higher than for the distribution network circuit breakers. For shedding light on the proper moment when the generator circuit-breaker must operate, using the space phasor of the short-circuit currents, the time expression to the first zero passing of the short-circuit current is determined. Here, the manner is investigated in which various factors influence the delay of the zero passing of the short-circuit current. It is shown that the delay time is influenced by the synchronous machine parameters and by the load conditions which precede the short-circuit. Numerical simulations were conducted of the asymmetrical currents in the case of the sudden three-phase short circuit at the terminals of synchronous generators. Further in this study it is emphasized that although the phenomena produced in the electric arc at the terminals of the circuit-breaker are complicated and not completely explained, the concept of exergy is useful in understanding the physical phenomena. The article points out that just after the short-circuit

  19. Thermal and Electrodynamic Risk of Residual Current Devices in the Case of Back-Up Protection by Overcurrent Circuit Breakers

    Directory of Open Access Journals (Sweden)

    Stanisław Czapp

    2014-12-01

    Full Text Available Residual current operated circuit breakers without integral overcurrent protection should be back-up protected. As back-up protection devices, overcurrent circuit breakers are used. The maximum let-through energy and let-through current of the overcurrent devices were evaluated under laboratory conditions. The thermal and electrodynamic risk of residual current devices was analyzed.

  20. Evaluation and Simulation of Black-box Arc Models for High-Voltage Circuit-Breakers

    OpenAIRE

    Gustavsson, Niklas

    2004-01-01

    The task for this Master thesis was to evaluate different black-box arc models for circuit-breakers with the purpose of finding criteria for the breaking ability. A black-box model is a model that requires no knowledge from the user of the underlying physical processes. Black-box arc models have been used in circuit-breaker development for many years. Arc voltages from tests made in the High Power Laboratory in Ludvika were used for validation, along with the resistance calculated at current ...

  1. Pressure and Arc Voltage Measurement in a 252 kV SF6 Puffer Circuit Breaker

    Science.gov (United States)

    Zhong, Jianying; Guo, Yujing; Zhang, Hao

    2016-05-01

    The pressure distribution in an arcing chamber is critically important for the SF6 puffer circuit breaker design. In this paper, the pressure variation of four locations in the nozzle was measured by piezoresistive and fiber optical pressure sensors at two current levels of 10 kA and 50 kA. An arc voltage measurement was also taken. The results demonstrate that using either type of sensor with a connecting tube is able to detect the fast pressure variation in circuit breakers, however the possible distortion and delay to the pressure transient caused by the tube need further study.

  2. Pressure and Arc Voltage Measurement in a 252 kV SF6 Puffer Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    ZHONG Jianying; GUO Yujing; ZHANG Hao

    2016-01-01

    The pressure distribution in an arcing chamber is critically important for the SF6 puffer circuit breaker design.In this paper,the pressure variation of four locations in the nozzle was measured by piezoresistive and fiber optical pressure sensors at two current levels of 10 kA and 50 kA.An arc voltage measurement was also taken.The results demonstrate that using either type of sensor with a connecting tube is able to detect the fast pressure variation in circuit breakers,however the possible distortion and delay to the pressure transient caused by the tube need further study.

  3. On-line Monitoring System based on Vibration Signal of High Voltage Circuit Breaker

    Directory of Open Access Journals (Sweden)

    Chao Fu

    2014-04-01

    Full Text Available High voltage circuit breaker is one of the most important switch apparatus in electrical power system. It play a role in the switch control, which can be used to switch the operating mode during normal operation (the equipment run or quit. In order to ensure the normal operation of the grid, it can be removed quickly when a malfunction on the device or circuit. Real-time online monitoring of high voltage circuit breaker can understand the running status, master the operation characteristics and its tend of development. As early as possible find the potential faults then take preventive measures timely, so as to ensure the reliable operation of power system. Online monitoring of high voltage circuit breakers can reduce the premature or unnecessary maintenance and maintenance cost, improve pertinence of the maintenance firstly. Secondly, it can improve the life of the switching device and improve the reliability of electric power system significantly. In this paper, on-line monitoring system based on vibration signal of high voltage circuit breaker is presented

  4. Research on The Mechanical State Parameter Extraction Method of High Voltage Circuit Breakers

    Directory of Open Access Journals (Sweden)

    Yang Tianxu

    2013-05-01

    Full Text Available High voltage circuit breakers play an important role in the power system. So it is necessary to implement the state detection of breakers in order to ensure stable and reliable running of the grid. The purpose of state detection is to provide reliable basis of maintenance by extracting mechanical state parameters accurately. This paper mainly focuses on the coil current signal feature extraction algorithm. To settle the problem of too much noise mixed with the current signal and signal distortion, the discrete wavelet transform algorithm is used to extract the coil current signal parameters. This paper also designs the FIR filter to extract stroke and speed parameters from travel-time waveform. The experiments show that the difference between the theoretical results and test results processed by the method in this paper is very small and the test results are able to accurately reflect operation states and mechanical features of high voltage circuit breakers.

  5. Pressure measurement in HV circuit-breaker; Mesure de pression dans un disjoncteur H.T.

    Energy Technology Data Exchange (ETDEWEB)

    Mottet, C. [Schneider Electric, Groupe appareillage, Lab. d' Essai A1, 75 - Paris (France)

    2002-06-01

    Electric arc pressure measurement in an HV circuit-breaker is fraught with difficulties concerning insulation, equi-potentiality, electromagnetic interference, corrosiveness of SF{sub 6} gas, and pressure and temperature rise. None of the many measurement methods attempted to data has proved wholly satisfactory. This article sets out an optical solution that does overcome the difficulties involved in measuring arc pressure. (author)

  6. Circuit-Breakers: Technical Terminology Bulletin. Terminotech, Vol. 1, No. 3.

    Science.gov (United States)

    General Electric Co. of Canada, Ltd., Montreal, Quebec.

    This issue of a bulletin of technological terminology is devoted to circuit breakers. A brief narrative on the subject is presented in both French and English. An English-French dictionary of terms comprises the bulk of the document. Explanatory illustrations are appended. (JB)

  7. The Implications of the Use of Parental Choice as a Legal "Circuit Breaker"

    Science.gov (United States)

    Mead, Julie F.; Lewis, Maria M.

    2016-01-01

    This study explores four instances where parental choice has been employed as a legal "circuit breaker": (a) First Amendment Establishment Clause cases related to public funding, (b) Fourteenth Amendment Equal Protection cases regarding race-conscious student assignment, (c) Title IX regulations concerning single-sex education, and (d) a…

  8. Online Monitoring System Design of Intelligent Circuit Breaker Based on DSP and ARM

    Directory of Open Access Journals (Sweden)

    Meng Song

    2014-08-01

    Full Text Available In order to accurately analyze the dynamic characteristics of the vacuum circuit breaker, a dual-core master-slave processor structure for online monitoring system based on DSP and ARM is proposed. This structure consists of host computer, lower computer and signal processing modules. The lower computer uses DSP as the core, which completes acquisition and data preprocessing of circuit breaker’s dynamic characteristics through sensors and signal conditioning circuits. The host computer uses ARM as the core which is responsible for task management, analysis, processing and displaying collected data via Ethernet. The communication between DSP and ARM is conducted by HPI. This design improves the reliability of intelligent control unit for the circuit breaker. The experiment showed that this system works steadily and accuracy.

  9. Numerical Simulation of Gas Flow During Arcing Process for 252 kV Puffer Circuit Breakers%Numerical Simulation of Gas Flow During Arcing Process for 252 kV Puffer Circuit Breakers

    Institute of Scientific and Technical Information of China (English)

    吴军辉; 王小华; 马志瀛; 荣命哲; 闫静

    2011-01-01

    A numerical simulation model for 252 kV puffer circuit breaker is constructed, by using a proven commercial computational fluid dynamics (CFD) package, PHOENICS. The model takes into account the moving parts in the circuit breaker, turbulence enhanced momentum and energy transport, radiation transport. The arcing process in a SF6 puffer circuit breaker with two hollow contacts is simulated under different conditions, and the simulation results are verified with experimental results. Through simulation, the pressure, temperature and velocity in the arc quenching chamber can be obtained. The simulation model is also capable of predicting the influence of design parameters variations on breaker performance, and can thus help to reduce the number of short-circuit tests during the design stage.

  10. Operating Circuit Fault Diagnosis of High Voltage Circuit Breaker%高压断路器操作回路的故障诊断

    Institute of Scientific and Technical Information of China (English)

    赵红宇; 龙树峰

    2015-01-01

    This paper analyzes and studies the fault diagnosis operation requirements of high voltage circuit breaker operation circuit and the fault diagnosis method of high voltage circuit breaker.%本文对高压断路器操作回路的故障诊断操作要求和高压断路器操作回路的故障诊断方法进行了分析和研究。

  11. Mechanical Fault Diagnosis for HV Circuit Breakers Based on Ensemble Empirical Mode Decomposition Energy Entropy and Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Jianfeng Zhang

    2015-01-01

    Full Text Available During the operation process of the high voltage circuit breaker, the changes of vibration signals can reflect the machinery states of the circuit breaker. The extraction of the vibration signal feature will directly influence the accuracy and practicability of fault diagnosis. This paper presents an extraction method based on ensemble empirical mode decomposition (EEMD. Firstly, the original vibration signals are decomposed into a finite number of stationary intrinsic mode functions (IMFs. Secondly, calculating the envelope of each IMF and separating the envelope by equal-time segment and then forming equal-time segment energy entropy to reflect the change of vibration signal are performed. At last, the energy entropies could serve as input vectors of support vector machine (SVM to identify the working state and fault pattern of the circuit breaker. Practical examples show that this diagnosis approach can identify effectively fault patterns of HV circuit breaker.

  12. Data Monitoring Recorder for Mechanical Properties of Release Coil in Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    XU Jianyuan; YANG Zhuangzhuang; LIN Xiangbin; LI Bin; LIU Yang

    2013-01-01

    A design of data monitoring recorder is introduced to ensure the stable work of circuit breakers.The recorder is mainly adopted to collect data of different mechanical properties of circuit breakers for real-time online working in power-industrial labs,and to set up a database including both correct information and fault information for assessing and diagnosing power systems.The recorder uses the master-slave detection core design which adopts both digital signal processor (DSP) and peripheral interface controller (PIC).Not-AND (NAND) flash memory is adopted as a mass storage unit,and the designed clock is used to identify the data being accessed.Access to data and communications between the upper computer and the lower computer are achieved through a universal serial bus (USB) communication.Results of an experiment further illustrate the accuracy and reliability of the data obtained by the proposed recorder.

  13. Dynamic Simulation and Opening Bouncing Analysis of Vacuum Circuit Breaker with Permanent Magnetic Actuator

    Institute of Scientific and Technical Information of China (English)

    LIN Xin; CAO Chen; LI Bin; LIU Yang; XU Jianyuan

    2013-01-01

    In order to research the dynamic characteristics of circuit breaker (CB) in opening process,taking a 12 kV vacuum circuit breaker (VCB) with permanent magnetic actuator as the example,a dynamic model of the VCB is established based on the virtual prototype technology,and dynamic equations of the model are deduced.Simulation and experiment are carried out on the VCB of both opening and closing processes.The simulative opening time and closing time are 39.5 ms and 54.6 ms respectively.Influencing factors of opening bouncing and their effect principles are analyzed through dynamic simulations of opening bouncing process.Analytic results indicate that the increase in the stiffness coefficient of contact spring limits the opening bouncing; meanwhile increases in the preload of contact spring and the mass of shaft can enlarge the opening bouncing.

  14. Effect of Circuit Breaker Shunt Resistance on Chaotic Ferroresonance in Voltage Transformer

    Directory of Open Access Journals (Sweden)

    RADMANESH, H.

    2010-08-01

    Full Text Available Ferroresonance or nonlinear resonance is a complex electrical phenomenon, which may cause over voltages and over currents in the electrical power system which endangers the system reliability and continuous safe operating. This paper studies the effect of circuit breaker shunt resistance on the control of chaotic ferroresonance in a voltage transformer. It is expected that this resistance generally can cause ferroresonance dropout. For confirmation this aspect Simulation has been done on a one phase voltage transformer rated 100VA, 275kV. The magnetization characteristic of the transformer is modeled by a single-value two-term polynomial with q=7. The simulation results reveal that considering the shunt resistance on the circuit breaker, exhibits a great mitigating effect on ferroresonance over voltages. Significant effect on the onset of chaos, the range of parameter values that may lead to chaos along with ferroresonance voltages has been obtained and presented.

  15. Research on the overload protection reliability of moulded case circuit-breakers and its test device

    Institute of Scientific and Technical Information of China (English)

    LI Kui; LU Jian-guo; WU Yi; QIN Zhi-jun; YAO Dong-mei

    2007-01-01

    This paper analyzed the reliability and put forward the reliability index of overload protection for moulded case circuit breaker. The success rate was adopted as its reliability index of overload protection. Based on the reliability index and the reliability level, the reliability examination plan was analyzed and a test device for the overload protection of moulded case circuit-breaker was developed. In the reliability test of overload protection, two power sources were used, which reduced the time of conversion and regulation between two different test currents in the overload protection test, which made the characteristic test more accurate. The test device was designed on the base of a Windows system, which made its operation simple and friendly.

  16. Thermal radiation effect on the extinction properties of electric arcs in HV circuit breakers

    Directory of Open Access Journals (Sweden)

    Ziani Abderrahmane

    2009-01-01

    Full Text Available During the formation of the electric arc at the opening of a high voltage circuit breaker, the generated plasma will be the seat of a very important thermal exchange. Models founded only on conduction and convection thermal transfers don't reproduce the whole thermal exchanges that are governing the extinction process. This paper is devoted to the development of a model of the electric arc extinction in a high voltage circuit breaker taking in account the thermal radiation of the plasma, in addition to the conduction and convection phenomena. The Stefan-Boltzman equation is coupled with the heat equation, and both equations are solved simultaneously in order to follow the evolution of the arc voltage and the conductance of the thermal plasma. The obtained results are found in good agreement with experimental recordings.

  17. IMPROVEMENT OF TRANSIENT STABILITY OF POWER SYSTEM USING SOLID STATE CIRCUIT BREAKER

    Directory of Open Access Journals (Sweden)

    Kalai Murugan Amirthalingam

    2013-01-01

    Full Text Available The aim of this study is to use a solid state circuit breaker for the improvement of transient stability margin. Long distance AC transmission is often subject to stability problems, which limits the transmission capability. Interconnected power systems suffer from weakly damped swings between synchronous generator and sub systems. The development of modern power system has lead to an increasing complexity in the study of power system and also presents new challenges to power system stability and in particular to the aspects of transient stability and small signal stability. Transient stability control plays a significant role in ensuring the stable operation of power systems in the event of large disturbances and faults and is thus a significant area of research. This study investigates the improvement of transient stability of a two area system, using Solid State Circuit Breaker which is capable of fast switching in case of faults and thus controlling the real and reactive power flows in a faulted transmission line. Simulations are carried out in Matlab/Simulink environment for two area system model with Solid State Circuit Breaker to analyze the effects of SSCB on transient stability performance of the system. From the simulation results, swing curves of the three phase faulted power system without SSCB gets increases monotonically and thus the system can be considered as unstable whereas the swing curves of the system with an SSCB reaches to a steady state.

  18. A Novel Approach to Power Circuit Breaker Design for Replacement of SF6

    Directory of Open Access Journals (Sweden)

    D. J. Telfer

    2004-01-01

    Full Text Available This contribution explores the role of PTFE ablation in enhancing current interruption for various background gases in high voltage circuit breakers. An assessment of the current interruption capability has been made in terms of the arcing duration and the contact gap length at which critical arc extinction is achieved. These observations are supported by measurements of the magnitude of extinction and re-ignition voltage peaks. Most previous and other current experimental work on gas filled circuit breaker design follows conventional wisdom in investigating arcing behaviours at elevated gas pressures (usually up to 6 bar. But in this work we concentrate on the effects of using low gas pressures (less than 1 bar in the presence of a close-fitting shield of ablatant polymer material (PTFE that surrounds the electrode assembly of an experimental high power circuit breaker. We demonstrate that for several different gases, arc extinction capability compares well under these conditions with SF6, suggesting that SF6 could be replaced entirely in this novel system by more environmentally friendly gases. Moreover, the critical contact gap lengths at extinction are only slightly greater than when using SF6 at 6 bar. Weight loss measurements from the ablatant shield suggest that a chemical puffer action is the most likely mechanism for achieving the observed arc extinctions in this system.

  19. Modeling and Simulation of Flexible Transmission Mechanism with Multiclearance Joints for Ultrahigh Voltage Circuit Breakers

    Directory of Open Access Journals (Sweden)

    Fangang Meng

    2015-01-01

    Full Text Available The transmission mechanism, of which the dynamic characteristics determine the reliability of the circuit breaker, is the principal component of the ultrahigh voltage (UHV circuit breaker. The characteristics of transmission mechanism are quick motion, high sensibility, and high reliability. The transmission mechanism with multiclearance joints present strong no-linear vibration feature which strongly affects the reliability of the UHV circuit breaker. In this investigation, a planar rigid-flexible coupling model of the transmission mechanism considering the clearance joints and the flexibility of components is established by using ADAMS software. The dynamic contact model in clearance joints is performed, based on clearance vector model of clearance joint. Then, the reliability of the model is proved by means of comparing the results of experiments. The simulation results show that the dynamic response of the mechanism is greatly influenced by the clearance and the flexibility of components has a role of suspension for the mechanism. Moreover, the influence of the clearance size, input speed, and number of clearance joints on the dynamic characteristics of the mechanism are also investigated.

  20. Solid-state recoverable fuse functions as circuit breaker

    Science.gov (United States)

    Thomas, E. F., Jr.

    1966-01-01

    Molded, conductive-epoxy recoverable fuse protects electronic circuits during overload conditions, and then permits them to continue to function immediately after the overload condition is removed. It has low resistance at ambient temperature, and high resistance at an elevated temperature.

  1. Fuzzy diagnostic system for oleo-pneumatic drive mechanism of high-voltage circuit breakers.

    Science.gov (United States)

    Nicolau, Viorel

    2013-01-01

    Many oil-based high-voltage circuit breakers are still in use in national power networks of developing countries, like those in Eastern Europe. Changing these breakers with new more reliable ones is not an easy task, due to their implementing costs. The acting device, called oleo-pneumatic mechanism (MOP), presents the highest fault rate from all components of circuit breaker. Therefore, online predictive diagnosis and early detection of the MOP fault tendencies are very important for their good functioning state. In this paper, fuzzy logic approach is used for the diagnosis of MOP-type drive mechanisms. Expert rules are generated to estimate the MOP functioning state, and a fuzzy system is proposed for predictive diagnosis. The fuzzy inputs give information about the number of starts and time of functioning per hour, in terms of short-term components, and their mean values. Several fuzzy systems were generated, using different sets of membership functions and rule bases, and their output performances are studied. Simulation results are presented based on an input data set, which contains hourly records of operating points for a time horizon of five years. The fuzzy systems work well, making an early detection of the MOP fault tendencies.

  2. Fuzzy Diagnostic System for Oleo-Pneumatic Drive Mechanism of High-Voltage Circuit Breakers

    Directory of Open Access Journals (Sweden)

    Viorel Nicolau

    2013-01-01

    Full Text Available Many oil-based high-voltage circuit breakers are still in use in national power networks of developing countries, like those in Eastern Europe. Changing these breakers with new more reliable ones is not an easy task, due to their implementing costs. The acting device, called oleo-pneumatic mechanism (MOP, presents the highest fault rate from all components of circuit breaker. Therefore, online predictive diagnosis and early detection of the MOP fault tendencies are very important for their good functioning state. In this paper, fuzzy logic approach is used for the diagnosis of MOP-type drive mechanisms. Expert rules are generated to estimate the MOP functioning state, and a fuzzy system is proposed for predictive diagnosis. The fuzzy inputs give information about the number of starts and time of functioning per hour, in terms of short-term components, and their mean values. Several fuzzy systems were generated, using different sets of membership functions and rule bases, and their output performances are studied. Simulation results are presented based on an input data set, which contains hourly records of operating points for a time horizon of five years. The fuzzy systems work well, making an early detection of the MOP fault tendencies.

  3. Discussion on Selectivity of Low Voltage Circuit Breakers%低压断路器的选择性探讨

    Institute of Scientific and Technical Information of China (English)

    何国标

    2014-01-01

    This paper introduces the principle of selectivity for low voltage circuit breakers in distribution line. Focus on the coordinate of several circuit breakers and selectivity of overload and short circuit. This paper describes the latest selectivity technology of low voltage circuit breakers at home and abroad.%本文介绍了在配电线路中对不同低压断路器进行选择的原则。着重阐述了几种断路器之间的配合,过载情况、短路情况下的选择性。并阐述了国内外现阶段最新的低压断路器的选择性技术。

  4. Development of High-Voltage Vacuum Circuit Breaker%高电压真空断路器的发展

    Institute of Scientific and Technical Information of China (English)

    吴红亚; 李建基

    2011-01-01

    六氟化硫断路器在高压断路器中居主导地位,而真空断路器在中压领域占绝对优势,并在高电压领域崭露头角。阐述了开发高电压真空断路器的必要性,介绍了现有产品的结构与特点,并提出了研发高电压真空断路器需解决的技术问题及相关的应对措施。%Sulfur hexafluoride circuit breakers take a leading position in high-voltage circuit breakers and vacuum circuit breakers hold all the trumps in medium voltage field,making a figure in high-voltage field.Description was made to the necessity of development of high-voltage vacuum circuit breakers.Introduction was made to structure and features of the existing products.This paper raised technical issues to be solved in RD of high-voltage vacuum circuit breakers and their related countermeasures.

  5. Measured turbulent mixing in a small-scale circuit breaker model.

    Science.gov (United States)

    Basse, N P T; Bini, R; Seeger, M

    2009-11-10

    The performance of high voltage gas circuit breakers depends on the temperature distribution of hot gas or plasma from the arc zone mixed with cold gas that is present, for example, in the exhausts and mixing volume. Understanding the details of the mixing process is imperative to estimate the temperature distribution within the entire breaker volume. Design studies rely on computational fluid dynamics (CFD) simulations to search for the best way to achieve satisfactory mixing. One key uncertainty in the CFD simulations is the role of turbulence in this process and how to properly account for it. To gain knowledge of the mixing process between hot and cold gases, we have constructed a simplified breaker geometry that is flexible and accessible to diagnostics. Apart from standard measurements of current and arc voltage, we measure pressure in the arc zone and the mixing volume. Further, the mixing volume is specially designed to be transparent, allowing us to make shadowgraphy measurements of the turbulent mixing during and after the arcing phase. We report on experiments performed in air at atmospheric pressure.

  6. Air blast circuit breaker noise and hearing loss: a multifactorial model for risk assessment.

    Science.gov (United States)

    McBride, D I; Williams, S

    2000-04-01

    The assessment of the risk to hearing from impulse noise exposure may be a problem for the occupational physician because existing legislative and international noise exposure standards deal primarily with continuous noise, and are not valid in excess of the peak exposure limit of 200 pa (140 dB). Noise exposure in excess of this level, for example that due to firearms, is frequently perceived as harmful, but this is not necessarily the case, as impulse noise standards do, in fact, allow exposure with a maximum in the order of 6.3 kPa (170 dB). To illustrate this, a cross-sectional group of electrical transmission workers have been studied who were exposed to significant levels of impulse noise from air blast circuit breakers and firearms. Important hearing loss factors have been identified by means of a specially designed questionnaire. Using the Health & Safety Executive definition, the risk of hearing loss was determined by calculating prevalence odds ratios (ORs) for exposure to these factors. The OR for those with fewer than eight unprotected air blast circuit breaker exposures was 2.27 (95% confidence interval (CI), 1.01-5.08), whilst for those with more than eight exposures the OR was 2.10 (95% CI, 0.97-4.54). For firearm exposure, ORs of 1.61 (95% CI, 0.95-2.74) were noted in the medium exposure group and 2.05 (95% CI, 1.08-3.86) in the high exposure group. When all the factors were included in the model, the most significant factor was age. The study gives support to the impulse noise exposure criteria, confirming the borderline risk from air blast circuit breaker noise exposure and the relative safety of moderate gunfire exposure.

  7. Study on Restrike Phenomena for 40.5-kV Vacuum Circuit Breakers

    Institute of Scientific and Technical Information of China (English)

    Yan Jing; Ma Zhiying

    2006-01-01

    When interrupting short circuit fault by 40.5-Kv vacuum circuit breakers, it is significant to eliminate multiple restrike phenomena, which occur frequently and result in high overvoltage and even interruption failure. A synthetic circuit that can supply a DC recovery voltage after current zero was used to study multiple restrike phenomena in switching. Some key factors including breaking current, clearance between open contacts, electrode structure and contact material, which may affect restrike characteristics, were studied. Under various clearances, the statistical probability of restrike was obtained. As a result, the best scope of clearance between open contacts was found. The performance of CuCrS0/50 and CuCr75/25 material were compared. Two kinds of electrode structures, namely 1/2 coil structure and cup-shaped axial magnetic structure, were tested. After a high-current interruption, conditioning effect was realized and the probability ofrestrike decreased.

  8. Transient studies in large offshore wind farms, taking into account network/circuit breaker interaction

    DEFF Research Database (Denmark)

    Glasdam, Jacob Bærholm; Bak, Claus Leth; Hjerrild, Jesper

    2011-01-01

    to ensure reliable switching operations. Transient measurement results in an OWF are compared with simulation results in PSCAD EMTDC and DigSILENT Power Factory, where a user-defined model of the vacuum circuit breaker (VCB) is included, capable of simulating multiple prestrikes during the closing operation....... An analysis of the switching transients that might occur in an OWF will be made on basis of the validated model and the importance of the inclusion of a sufficient accurate representation of the VCB in the simulation tool will be described. The inclusion of the VCB model in PSCAD greatly improves...

  9. Simulation of the Effects of Several Factors on Arc Plasma Behavior in Low Voltage Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Taking into account the properties of the arc plasma and the electromagnetic, heat and radiative phenomena, commercial computational fluid dynamics software PHOENICS has been adapted and modified to develop the three-dimensional magneto-hydrodynamic (MHD)model of arc in a low voltage circuit breaker. The effects of the arc ignition location, venting size and gassing material on arc behavior have been investigated. The analysis of the results show that the arc velocity accelerates with the increase in the distance between arc ignition location and of the venting size, and the existence of the gassing material is beneficial to improving the arc voltage and reducing the arc temperature.

  10. Optical fiber imaging for high speed plasma motion diagnostics: applied to low voltage circuit breakers.

    Science.gov (United States)

    McBride, J W; Balestrero, A; Ghezzi, L; Tribulato, G; Cross, K J

    2010-05-01

    An integrated portable measurement system is described for the study of high speed and high temperature unsteady plasma flows such as those found in the vicinity of high current switching arcs. An array of optical fibers allows the formation of low spatial resolution images, with a maximum capture rate of 1 x 10(6) images per second (1 MHz), with 8 bit intensity resolution. Novel software techniques are reported to allow imaging of the arc; and to measure arc trajectories. Results are presented on high current (2 kA) discharge events in a model test fixture and on the application to a commercial low voltage circuit breaker.

  11. "Report to the Legislature on": The Implementation of the Special Education Reimbursement ("Circuit Breaker") Program. Line-Item 7061-0012

    Science.gov (United States)

    Massachusetts Department of Education, 2008

    2008-01-01

    This paper reports on the implementation of the Special Education Reimbursement ("Circuit Breaker") Program. Fiscal Year 2007 is the fourth year implementing the Circuit Breaker reimbursement program which provides additional state support for students with disabilities. School districts are eligible for a reimbursement of eligible costs…

  12. Proposal to negotiate, without competitive tendering, a contract for the maintenance of three 420 kV circuit breakers

    CERN Document Server

    2000-01-01

    This document concerns the award of a contract for the maintenance, by the manufacturer, of three 420 kV circuit breakers. The Finance Committee is invited to agree to the negotiation of a contract, without competitive tendering, with SCHNEIDER ITALY (IT) (formerly NUOVA MAGRINI GALILEO), the manufacturer of the equipment, for the maintenance of three 420 kV circuit breakers for a total amount of 490 000 Swiss francs, not subject to revision. The firm has indicated the following distribution by country of the contract value covered by this adjudication proposal: IT?100%.

  13. Study on the Mathematical Model of Dielectric Recovery Characteristics in High Voltage SF6 Circuit Breaker

    Science.gov (United States)

    Lin, Xin; Wang, Feiming; Xu, Jianyuan; Xia, Yalong; Liu, Weidong

    2016-03-01

    According to the stream theory, this paper proposes a mathematical model of the dielectric recovery characteristic based on the two-temperature ionization equilibrium equation. Taking the dynamic variation of charged particle's ionization and attachment into account, this model can be used in collaboration with the Coulomb collision model, which gives the relationship of the heavy particle temperature and electron temperature to calculate the electron density and temperature under different pressure and electric field conditions, so as to deliver the breakdown electric field strength under different pressure conditions. Meanwhile an experiment loop of the circuit breaker has been built to measure the breakdown voltage. It is shown that calculated results are in conformity with experiment results on the whole while results based on the stream criterion are larger than experiment results. This indicates that the mathematical model proposed here is more accurate for calculating the dielectric recovery characteristic, it is derived from the stream model with some improvement and refinement and has great significance for increasing the simulation accuracy of circuit breaker's interruption characteristic. supported by Science and Technology Project of State Grid Corporation of China (No. GY17201200063), National Natural Science Foundation of China (No. 51277123), Basic Research Project of Liaoning Key Laboratory of Education Department (LZ2015055)

  14. On-line condition monitoring systems for high voltage circuit breakers : a collaborative research project 1997-2001

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    A three year field project was initiated to review and evaluate the state of the art in on-line conditioning monitoring technology for a high voltage (240 kV SF6) circuit breaker located at Dorsey Converter Station. The ELF breaker is a three independent pole design which allows for three separate monitoring systems. This project involved the installation of a different type of monitoring system on each phase and incorporated many types of transducers. Each monitoring system measured the same basic parameters including contact travel, 'a' and 'b' auxiliary contacts, phase currents, coil currents, heater and pump current, plus SF6/CF4 pressure and temperature. Over the entire monitoring period the breaker was operated over 700 times at rated voltage and an additional 300 times during maintenance. Temperature conditions ranged from -35 to +30 degrees C. The use of on-line monitoring provided many valuable results and enhanced the knowledge base for the apparatus under the test. It was determined that on-line monitoring of HV circuit breakers has potential, but installation has to be considered carefully. Monitoring systems can offer improvement in the understanding of how circuit breakers work and provide input into RCM programs. However, monitoring systems themselves are subject to failure and require maintenance and attention. 2 refs., 2 tabs., 7 figs.

  15. Study of switching electric circuits with DC hybrid breaker, one stage

    Science.gov (United States)

    Niculescu, T.; Marcu, M.; Popescu, F. G.

    2016-06-01

    The paper presents a method of extinguishing the electric arc that occurs between the contacts of direct current breakers. The method consists of using an LC type extinguishing group to be optimally sized. From this point of view is presented a theoretical approach to the phenomena that occurs immediately after disconnecting the load and the specific diagrams are drawn. Using these, the elements extinguishing group we can choose. At the second part of the paper there is presented an analyses of the circuit switching process by decomposing the process in particular time sequences. For every time interval there was conceived a numerical simulation model in MATLAB-SIMULINK medium which integrates the characteristic differential equation and plots the capacitor voltage variation diagram and the circuit dumping current diagram.

  16. 500 kV断路器断口击穿故障与防护措施分析%Research on Breaker Breakdown and Protecting Measures of 500 kV Circuit Breakers

    Institute of Scientific and Technical Information of China (English)

    徐党国; 李雨; 孙云生; 刘平; 骆立实; 张恩伟

    2013-01-01

    通过对几起500 kV断路器断口击穿故障的分析表明,断路器断口发生击穿后,无论是灭弧室内部断口击穿还是断口外绝缘表面闪络,故障电弧均不能自行熄灭,同时由于断口闪络电流较小且没有对地故障,各种保护装置均不能快速动作.持续燃烧数秒钟的电弧使灭弧室严重发热,劣化SF6气体,并引发断路器爆炸等更严重的设备故障.带有并联电抗器的线路断路器及发变组断路器发生断口闪络故障的风险较高.笔者在对断口闪络故障的原因进行分析的基础上,认为对断路器加装断口闪络保护可避免断口闪络引发设备故障,并分别针对带有并联电抗器的线路断路器和发变组断路器,对断口闪络保护的策略及保护定值进行了分析.%Four breaker breakdown are discribed in this paper. Either insulation defect or mechanical error may cause breaker breakdown of circuit breakers. And the faults cannot be cleared automatically when breakdown happened due to the system voltage. The fault current of breaker breakdown is quite small than the short circuit current as there is no phase to ground fault. None protection operates immediately when breaker breakdown happens and the electric-arc buries between breakers for few seconds. The circuit breaker and the SF6 gas may be damaged during the arc buries. The protecting devices do not operate until the breakdown between the contacts becomes a phase-to-ground and the fault current increases rapiddly. The circuit breakers of EHV transmission line with parralle reactor and breakers of generator-transformer unit have higher risk of breaker flashover than other circuit breakers. The reason of breaker flashover of circuit breakers are analyzed in this paper. Breaker flashover protection of circuit breaker are introduced to protect the circuit breakers from damagement during breaker breakdown faults. The protection setting and time delay of breaker flashover protection for

  17. Transient Studies in Large Offshore Wind Farms, Tak-ing Into Account Network/Circuit Breaker Interaction

    DEFF Research Database (Denmark)

    Glasdam, Jakob; Bak, Claus Leth; Hjerrild, Jesper;

    2011-01-01

    to ensure reliable switching operations. Transient measurement results in an OWF are compared with simulation results in PSCAD EMTDC and DigSILENT Power Factory, where a user-defined model of the vacuum circuit breaker (VCB) is included, capable of simulating multiple prestrikes during the closing operation...

  18. Numerical modeling of high-voltage circuit breaker arcs and their interraction with the power system

    Science.gov (United States)

    Orama, Lionel R.

    In this work the interaction between series connected gas and vacuum circuit breaker arcs has been studied. The breakdown phenomena in vacuum interrupters during the post arc current period have been of special interest. Numerical models of gas and vacuum arcs were developed in the form of black box models. Especially, the vacuum post arc model was implemented by combining the existing transition model with an ion density function and expressions for the breakdown mechanisms. The test series studied reflect that for electric fields on the order of 10sp7V/m over the anode, the breakdown of the vacuum gap can result from a combination of both thermal and electrical stresses. For a particular vacuum device, the vacuum model helps to find the interruption limits of the electric field and power density over the anode. The series connection of gas and vacuum interrupters always performs better than the single gas device. Moreover, to take advantage of the good characteristics of both devices, the time between the current zero crossing in each interrupter can be changed. This current zero synchronization is controlled by changing the capacitance in parallel to the gas device. This gas/vacuum interrupter is suitable for interruption of very stressful short circuits in which the product of the dI/dt before current zero and the dV/dt after current zero is very high. Also, a single SF6 interrupter can be replaced by an air circuit breaker of the same voltage rating in series with a vacuum device without compromising the good performance of the SF6 device. Conceptually, a series connected vacuum device can be used for high voltage applications with equal distribution of electrical stresses between the individual interrupters. The equalization can be made by a sequential opening of the individual contact pairs, beginning with the interruptors that are closer to ground potential. This could eliminate the use of grading capacitors.

  19. Improving Transient Recovery voltage of circuit breaker using Fault Current Limiter

    Directory of Open Access Journals (Sweden)

    Amir Heidary

    2012-12-01

    Full Text Available This study investigates influence of Fault Current Limiter (FCL on short-circuits current level of substation bus bar splitter circuit breaker and its TRV. An approach for TRV evaluation is developed and applied for proposed power system as shown in this study. FCL circuit is connected to the power system in order to limit TRV. The limiter circuit consists of two equal windings which are turned around unique magnetic core. One of the windings is connected in series with the power system network and the other is connected to the network via series capacitor and power electronic switches. During normal operating condition, both tyristors are in on state and current of the primary and secondary windings are equal. This causes zero impedance of the limiter. During fault, faults current cause the power electronic switch to turn off which increases the limiter impedance. By increasing the limiter impedance, amplitude of TRV decreases substantially. The novel method presented in this study is a cheap and successful scheme.

  20. Power nanosecond pulse shaping by means of RCD-generators with peaking circuits based on diode current breakers

    CERN Document Server

    Grekhov, I V; Korotkov, S V; Stepanyants, A L; Khristyuk, D V

    2002-01-01

    One considered the basic principles to design nanosecond region generators based on reverse-connected dynistos (RCD) with diode current breaker base output peaking circuits. Paper presents the results of experimental investigation in intense generator based on RCD, peaking pulsed transformer and high-voltage diode breaker from a set of series-connected drift diodes with abrupt reset. Generator at 1 kHz frequency commutates voltage pulses with approx 45 kV amplitude, approx 50 ns duration and approx 10 ns rise front to 25 ohm load

  1. Transient Studies in Large Offshore Wind Farms, Employing Detailed Circuit Breaker Representation

    DEFF Research Database (Denmark)

    Glasdam, Jakob Bærholm; Bak, Claus Leth; Hjerrild, Jesper

    2012-01-01

    in order to ensure reliable switching operations. Transient measurement results in an OWF are compared with simulation results in PSCAD EMTDC and DigSILENT Power Factory. A user-defined model of the vacuum circuit breaker (VCB) is included in both tools, capable of simulating multiple prestrikes during...... the closing operation. An analysis of the switching transients that might occur in OWFs will be made on the basis of the validated model, and the importance of the inclusion of a sufficiently accurate representation of the VCB in the simulation tool will be described. The inclusion of the VCB model in PSCAD...... greatly improves the simulation results, whereas little improvement is found in DigSILENT. Based on the transient study it is found that the simulated SOV can be up to 60% higher at the sending end when using the detailed VCB representation compared to the built-in switch, which emphasises the need...

  2. The Influence of Contact Space on Arc Commutation Process in Air Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    NIU Chunping; DING Juwen; YANG Fei; DONG Delong; RONG Mingzhe; XU Dan

    2016-01-01

    In this paper,a 3D magneto-hydrodynamic (MHD) arc simulation model is applied to analyze the arc motion during current interruption in a certain air circuit breaker (ACB).The distributions of pressure,temperature,gas flow and current density of the arc plasma in the arc region are calculated,and the factors influencing the commutation process are analyzed according to the calculated results.Based on the airflow in the arc chamber,the causes of arc commutation asynchrony and the back commutation are investigated.It indicates that a reasonable contact space design is crucial to a successful arc commutation process.To verify the simulation results,the influence of contact space on arc voltage and arc commutation is tested.This research can provide methods and references to the optimization of ACB design.

  3. Reduction of Switching Surge by Controlled Shunt Reactor Switching of Gas Circuit Breaker

    Science.gov (United States)

    Kohyama, Haruhiko; Ito, Hiroki; Asai, Jun; Hidaka, Mikio; Yonezawa, Takashi

    Controlled switching system (CSS) with a 204kV gas circuit breaker (GCB) demonstrates to reduce an inrush current and to eliminate re-ignitions in shunt reactor switching. Target closing and opening instants for controlled switching are determined by the electrical and mechanical characteristics of GCB. Idle time dependence of the operating time, which gives a sufficient impact on controlling accuracy, is evaluated and successfully compensated by synchronous switching controller (SSC). Field operation of CSS for a year shows an effective suppression of inrush current on closing and prevention of re-ignitions on opening of shunt reactor. The operations also proved that the CSS has a satisfactory performance for electro-magnetic disturbance imposed in practical field.

  4. New Breakdown Electric Field Calculation for SF6 High Voltage Circuit Breaker Applications

    Institute of Scientific and Technical Information of China (English)

    Ph.ROBIN-JOUAN; M.YOUSFI

    2007-01-01

    The critical electric fields of hot SF6 are calculated including both electron and ion kinetics in wide ranges of temperature and pressure,namely from 300 K up to 4000 K and 2 atmospheres up to 32 atmospheres respectively.Based on solving a multi-term electron Boltzmann equation the calculations use improved electron-gas collision cross sections for twelve SF6 dissociation products with a particular emphasis on the electron-vibrating molecule interactions.The ion kinetics is also considered and its role on the critical field becomes non negligible as the temperature is above 2000 K.These critical fields are then used in hydrodynamics simulations which correctly predict the circuit breaker behaviours observed in the case of breaking tests.

  5. Influencing Factors of Breaking Capacity of Double-Break Vacuum Circuit Breakers

    Directory of Open Access Journals (Sweden)

    Shengwen Shu

    2013-06-01

    Full Text Available Using a series arrangement of two vacuum interrupters (VIs has been proved to be an effective way of developing higher voltage vacuum circuit breakers (VCBs, which are known as double-break VCBs. The uniform distribution of the transient recovery voltage (TRV across each VI is very critical for the breaking capacity of double-break VCBs. In this paper, the TRV distribution characteristics of double-break VCBs was studied by the synthetic test and the PSCAD/EMTDC simulation based on a vacuum arc interruption model. The results show that the bias of the TRV distribution ratio is caused by the stray capacitance and the imbalanced post arc plasma characteristic in each VI, which is consistent with the theoretical analysis. Moreover, the negative effect of grading capacitors was discussed. The results show that it is advisable to limit the value of grading capacitors to those ranges which can guarantee sufficiently improve the voltage distribution.

  6. 浅析断路器控制回路故障处理%Treatment of Circuit Breaker Control Circuit Fault

    Institute of Scientific and Technical Information of China (English)

    杨志钧

    2014-01-01

    断路器提高整个电力系统正常运转的稳定及可靠性,对电力系统运转有着极为重要的作用,而断路器上较为重要的一个技术环节就是控制回路,控制回路是每个运行及电力检修员工都必须要会的基本技能,本文将结合断路器中控制回路常出现的一些问题进行分析,希望能够对电路检修有所帮助。%The circuit breaker can improve the stability and reliability of the whole power system, so it has great importance for the power system. An important technology link of the circuit breaker is the control circuit, which is the required skill of each operation and electric power maintenance staff. This paper analyzes the common problems in circuit breaker control circuit in order to provide help for circuit maintenance.

  7. Vacuum interrupter, high reliability component of distribution switches, circuit breakers and contactors

    Institute of Scientific and Technical Information of China (English)

    SLADE Paul G.; LI Wang-pei; MAYO Stephen; SMITH R.Kirkland; TAYLOR Erik D.

    2007-01-01

    The use of vacuum interrupters (VIs) as the current interruption component for switches, circuit breakers, reclosers and contactors operating at distribution voltages has escalated since their introduction in the mid-1950's. This electrical product has developed a dominating position for switching and protecting distribution circuits. VIs are even being introduced into switching products operating at transmission voltages. Among the reasons for the VI's popularity are its compactness, its range of application, its low cost, its superb electrical and mechanical life and its ease of application. Its major advantage is its well-established reliability. In this paper we show how this reliability has been achieved by design, by mechanical life testing and by electrical performance testing. We introduce the "sealed for life" concept for the VI's integrity. We discuss this in terms of what is meant by a practical leak rate for VIs with a life of over 30 years. We show that a simple high voltage withstand test is an easy and effective method for monitoring the long-term vacuum integrity. Finally we evaluate the need for routine inspection of this electrical product when it is used in adverse ambient environments.

  8. Investigating influence of the magnetic arc blow in multi-break vacuum circuit breakers

    Science.gov (United States)

    Liao, Minfu; Ge, Guowei; Duan, Xiongying; Huang, Zhihui; Zou, Jiyan

    2016-12-01

    This paper investigates the influence of the interactive magnetic field in multi-break vacuum circuit breakers (VCBs) on the arc plasma and the post-arc characteristics. The magnetic field of multi-break VCBs is asymmetric and off-center because of the interactive magnetic field, which is also called bias magnetic field (BMF). The BMF distribution of double-break VCBs is gained by electromagnetic analysis. The test circuit of the magnetic arc blow in multi-break VCBs is established by simplifying as the interaction between the vacuum arc and the BMF. The influence of the magnetic arc blow on the arc plasma is studied by the high-speed CMOS camera and the post-arc current measure. While the vacuum arc is in the direction of the Ampere force with the BMF at 200 mT, it is in the retrograde direction when the BMF is below 100 mT, which results in the post-arc charge obviously varying from 9 μC to 50 μC. The relationship between the BMF and the post arc charge is gained. The mechanism of the magnetic arc blow in multi-break VCBs is discussed. Therefore, this paper can provide the base of construct and configuration to avoid the influence of the magnetic arc blow.

  9. 基于STM32智能断路器的设计%The Design of Intelligent Circuit Breaker Based on STM32

    Institute of Scientific and Technical Information of China (English)

    刘勇军

    2014-01-01

    Taking the molded case intelligent circuit breakers of AdaptCan series of CHANGZHENG for example, this paper describes the design of intelligent circuit breaker based on STM32F series MCU.%本文以贵州长征的AdaptCan系列塑壳智能断路器为例,介绍了基于STM32F系列单片机(MCU)的智能断路器的设计。

  10. Automated Monitoring for Circuit Breaker on Line%断路器运行在线自动监测

    Institute of Scientific and Technical Information of China (English)

    邰超

    2011-01-01

    断路器在电力系统中非常重要,用它来切换其他设备在工作与停止两种状态。断路器的可靠运行对重新配置电力系统的能力至关重要,并且可靠性可以通过定期检查和维护来保证。现在可以采用一种自动断路器监测系统来监测断路器的控制电路。系统包括一套新的断路器监测数据采集智能电子设备,它位于断路器上,用于获得关于实时运行的详细信息。本文也论证了系统范围的数据分析的应用,它使得追踪断路器的开关序列成为可能,同时也给出了关于断路器开关序列的性能和最终结果的结论。%Circuit breakers (CBs) are very important elements in the power system. They are used to switch other equipment in and out of service. Reliable operation of circuit breakers is critical to the ability to reconfigure a power system and can be assured by regular inspection and maintenance. An automated circuit breaker monitoring system is proposed to monitor circuit breaker's control circuit. The system consists of a new CB monitoring data acquisition IED that is located at circuit breaker and captures detailed information about its operation in real-time, An application of system wide data analysis is demonstrated. It makes possible to track the circuit breaker switching sequences and make conclusions about their performance and final outcome.

  11. Analytical Analysis and Case Study of Transient Behavior of Inrush Current in Power Transformer for Designing of Efficient Circuit Breakers

    Science.gov (United States)

    Harmanpreet, Singh, Sukhwinder; Kumar, Ashok; Kaur, Parneet

    2010-11-01

    Stability & security are main aspects in electrical power systems. Transformer protection is major issue of concern to system operation. There are many mall-trip cases of transformer protection are caused by inrush current problems. The phenomenon of transformer inrush current has been discussed in many papers since 1958. In this paper analytical analysis of inrush current in a transformer switched on dc and ac supply has been done. This analysis will help in design aspects of circuit breakers for better performance.

  12. A new generation of medium-voltage switchboards and circuit-breakers; Eine neue Generation von Mittelspannungsschaltanlagen und -leistungsschaltern

    Energy Technology Data Exchange (ETDEWEB)

    Saemann, D.; Weichert, R.; Werner, S. [Siemens AG, Erlangen (Germany). Bereich Energieuebertragung und -verteilung

    1998-04-06

    Todays market and the trend towards globalization of business both call for new products. The authors describe the new generation of medium-voltage switchgears and circuit-breakers, along with the benefit they bring for customers. (orig./RHM) [Deutsch] Der Markt und die Globalisierung des Geschaeftes fordern neue Produkte. Die Verfasser beschreiben die neue Generation von Mittelspannungsschaltanlagen und -schaltern sowie deren Nutzen fuer die Anwender. (orig./RHM)

  13. Current identification in vacuum circuit breakers as a least squares problem*

    Directory of Open Access Journals (Sweden)

    Ghezzi Luca

    2013-01-01

    Full Text Available In this work, a magnetostatic inverse problem is solved, in order to reconstruct the electric current distribution inside high voltage, vacuum circuit breakers from measurements of the outside magnetic field. The (rectangular final algebraic linear system is solved in the least square sense, by involving a regularized singular value decomposition of the system matrix. An approximated distribution of the electric current is thus returned, without the theoretical problem which is encountered with optical methods of matching light to temperature and finally to current density. The feasibility is justified from the computational point of view as the (industrial goal is to evaluate whether, or to what extent in terms of accuracy, a given experimental set-up (number and noise level of sensors is adequate to work as a “magnetic camera” for a given circuit breaker. Dans cet article, on résout un problème inverse magnétostatique pour déterminer la distribution du courant électrique dans le vide d’un disjoncteur à haute tension à partir des mesures du champ magnétique extérieur. Le système algébrique (rectangulaire final est résolu au sens des moindres carrés en faisant appel à une décomposition en valeurs singulières regularisée de la matrice du système. On obtient ainsi une approximation de la distribution du courant électrique sans le problème théorique propre des méthodes optiques qui est celui de relier la lumière à la température et donc à la densité du courant. La faisabilité est justifiée d’un point de vue numérique car le but (industriel est d’évaluer si, ou à quelle précision, un dispositif expérimental donné (nombre et seuil limite de bruit des senseurs peut travailler comme une “caméra magnétique” pour un certain disjoncteur.

  14. Modeling and Computer Simulation of the Pulsed Powering of Mechanical D.C. Circuit Breakers for the CERN/LHC Superconducting Magnet Energy Extraction System

    CERN Document Server

    Anushat, V; Erokhin, A; Kussul, A; Medvedko, A S

    2000-01-01

    This article presents the results of modeling and computer simulation of non-linear devices such as the Electromagnetic Driver of a D.C. Circuit Breaker. The mechanical and electromagnetic parts of the Driver are represented as equivalent electrical circuits and all basic processes of the Driver's magnetic circuit are calculated.

  15. Influence of Copper Vapor on Low-Voltage Circuit Breaker Arcs During Stationary and Moving States

    Institute of Scientific and Technical Information of China (English)

    MA Qiang; RONG Mingzhe; WU Yi; XU Tiejun; SUN Zhiqiang

    2008-01-01

    The influence of copper vapor on the low-voltage circuit breaker arcs is studied. A three-dimensional (3-D) magnetohydrodynamics(MHD) model of arc motion under the effect of external magnetic field is built up. By adopting the commercial computational fluid dynamics (CFD) package FLUENT based on control-volume method, the above MHD model is solved. For the mediums of air-1% Cu and air-10% Cu, the distributions of stationary temperature, pressure, electrical potential and the arc motion processes are compared with those of a pure air arc. The copper vapor diffusion process in the arc chamber and the distribution of copper vapor mass concentration are also simulated. The results shows that the copper vapor has a cooling effect on the arc plasma and can decrease the stationary voltage as well. Moreover, the presence of copper vapor can decelerate the arc motion in the quenching chambers. The maximal copper vapor concentration locates behind the arc root because of the existence of a "double vortex" near the electrodes.

  16. Numerical Study on Arc Plasma Behavior During Arc Commutation Process in Direct Current Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    杨飞; 马瑞光; 吴翊; 孙昊; 纽春萍; 荣命哲

    2012-01-01

    This paper focuses on the numerical investigation of arc plasma behavior during arc commutation process in a medium-voltage direct current circuit breaker (DCCB) contact system. A three-dimensional magneto-hydrodynamic (MHD) model of air arc plasma in the contact system of a DCCB is developed, based on commercial software FLUENT. Coupled electromagnetic and gas dynamic interactions are considered as usual, and a thin layer of nonlinear electrical resistance elements is used to represent the voltage drop of plasma sheath and the formation of new arc root. The distributions of pressure, temperature, gas flow and current density of arc plasma in arc region are calculated. The simulation results indicate that the pressure distribution related to the contact system has a strong effect on the arc commutation process, arising from the change of electrical conductivity in the arc root region. In DCCB contact system, the pressure of arc root region will be concentrated and higher if the space above the moving contact is enclosed, which is not good for arc root commutation. However, when the region is opened, the pressure distribution would be lower and more evenly, which is favorable for the arc root commutation.

  17. Simulation and Experimental Study of Arc Column Expansion After Ignition in Low-Voltage Circuit Breakers

    Institute of Scientific and Technical Information of China (English)

    MA Qiang; RONG Mingzhe; WU Yi; XU Tiejun; SUN Zhiqiang

    2008-01-01

    The dynamicprocess of arc pressure and corresponding arc column expansion, which is the main feature after arc ignition and has a significant effect on the breaking behaviour of low -voltage circuit breakers, is studied. By constructing a three dimensional mathematical model of air arc plasma and adopting the Control Volume Method, the parameters of arc plasma including temperature and pressure axe obtained. The variations of pressure field and temperature field with time are simulated. The result indicates that there are six stages for the process of arc column expansion according to the variation of pressure in arc chamber. In the first stage, the maximal pressure locates in the region close to cathode, and in the second stage the maximal pressure shifts to the region close to the anode. In the third stage, the pressure difference between the middle of arc column and the ambient gas is very large, so the arc column begins to expand apparently. In the fourth stage, the pressure wave propagates towards both ends and the maximal pressure appears at the two ends when the pressure wave reaches both sidewalls. In the fifth stage, the pressure wave is reflected and collides in the middle of the arc chamber. In the last stage, the propagation and reflection of pressure wave will repeat several times until a steady burning state is reached. In addition, the experimental results of arc column expansion, corresponding to the arc pressure variation, are presented to verify the simulation results.

  18. Speckle measurements of density and temperature profiles in a model gas circuit breaker

    Science.gov (United States)

    Stoller, P. C.; Panousis, E.; Carstensen, J.; Doiron, C. B.; Färber, R.

    2015-01-01

    Speckle imaging was used to measure the density and temperature distribution in the arc zone of a model high voltage circuit breaker during the high current phase and under conditions simulating those present during current-zero crossings (current-zero-like arc); the arc was stabilized by a transonic, axial flow of synthetic air. A single probe beam was used; thus, accurate reconstruction was only possible for axially symmetric gas flows and arc channels. The displacement of speckles with respect to a reference image was converted to a line-of-sight integrated deflection angle, which was in turn converted into an axially symmetric refractive index distribution using a multistep process that made use of the inverse Radon transform. The Gladstone-Dale relation, which gives the index of refraction as a function of density, was extended to high temperatures by taking into account dissociation and ionization processes. The temperature and density were determined uniquely by assuming that the pressure distribution in the case of cold gas flow (in the absence of an arc) is not modified significantly by the arc. The electric conductivity distribution was calculated from the temperature profile and compared to measurements of the arc voltage and to previous results published in the literature for similar experimental conditions.

  19. Influence of a Circuit Breaker's Grading Capacitor on Controlled Transformer Switching

    Science.gov (United States)

    Corrodi, Yves; Kamei, Kenji; Kohyama, Haruhiko; Ito, Hiroki

    Controlled switching, taking into account the residual flux level within a transformer core, can effectively eliminate inrush currents. Many switching sequences assume the residual flux as a constant value, which can be obtained by a measurement after a transformer de-energization. However, in case of a transformer system that is switched by a circuit breaker equipped with a grading capacitor, the residual flux characteristic cannot be considered as constant. A source voltage will feed the deenergized transformer system through the grading capacitor, which will change the residual flux level and let oscillations appear. It follows that the optimal re-energization targets change and inrush currents might not be optimally minimized. Further, transient voltages based on line failures can influence the residual flux through a grading capacitor as well. At first, this paper evaluates the influence of a grading capacitor on the residual flux characteristic analytically. Further, measurements of two transformer systems at a varied de-energization instant and for different grading capacitors provide actual information for the development of future controller systems.

  20. Calculation of Nozzle Ablation During Arcing Period in an SF6 Auto-Expansion Circuit Breaker

    Science.gov (United States)

    Zhang, Junmin; Lu, Chunrong; Guan, Yonggang; Liu, Weidong

    2016-05-01

    The nozzle ablation process is described as two phases of heat and ablation in the interruption for an SF6 circuit breaker in this paper. Their mathematical models are established with the Fourier heat conduction differential equation respectively. The masses of nozzle ablation with different arc durations and arc currents are calculated through the model of the nozzle ablation combined with an MHD (magneto-hydrodynamic) arc model. The time of the temperature rise on the inner surface of the nozzle under a given energy flux and of reaching the pyrolysis temperature under different energy fluxes is respectively analyzed. The relations between the mass of nozzle ablation and breaking current and arc duration are obtained. The result shows that the absorbing energy process before the nozzle ablation can be neglected under the condition of the energy flux entering into nozzle q > 109 W/m2. The ablation is the severest during the high-current phase and the ablation mass increases rapidly with the breaking current and with arc duration respectively. supported by National Natural Science Foundation of China (Nos. 51177005 and 51477004)

  1. Self-commutated high-voltage direct current transmission with DC circuit breakers. Backbone for the energy policy turnaround; Selbstgefuehrte Hochspannungs-Gleichstromuebertragung mit DC-Leistungsschalter. Rueckgrat fuer die Energiewende

    Energy Technology Data Exchange (ETDEWEB)

    Goerner, Raphael [ABB AG, Mannheim (Germany). Marketing und Vertrieb, Geschaeftsbereich Grid Systems

    2013-06-01

    The 'current war' between direct current and alternating current is extended by a new location. In the future, both technologies work together in order to provide a reliable power transmission in Germany and long-term in Europe. This is based on the self-guided high-voltage direct current transmission. In conjunction with direct current circuit breakers (DC circuit breaker) the power circuit breakers may help to make the transmission grids more flexible and to minimize losses.

  2. Analysis on Dynamic Dielectric Recovery and Statistical Property of Vacuum Circuit-Breakers with Multi-Breaks

    Institute of Scientific and Technical Information of China (English)

    廖敏夫; 段雄英; 邹积岩

    2004-01-01

    Based on the dynamic dielectric recovery process in the vacuum gaps in series, investigations were made on post-arc insulation state in double and multi-breaks operation in high voltage power system. From the research on the breakdown weak points in high voltage vacuum gaps, their turnout and distribution, some theoretic work were made to set up the models for describing the statistical property of multi-breaks vacuum circuit-breakers' breakdown and post-arc re-strike, which can be used for explaining the mechanism of the improvement in the breaking capacity of multi-breaks units compared with that of single-break ones which have the same equivalent gap length. The advantages of vacuum breakers with multi-breaks are proposed.

  3. 断路器防跳回路缺陷分析及改造方法%Detects Analysis of Anti-Skip Circuit for Circuit Breaker and Its Improvements

    Institute of Scientific and Technical Information of China (English)

    王文昕; 阳书雯; 李巧荣

    2015-01-01

    按照二次回路反事故措施要求,断路器防跳功能的设计必须使用机构内防跳回路。文章在分析断路器防跳回路工作原理的基础上,以察汗乌苏水电站中断路器的两例缺陷为例,提出了改造方法。%According to anti-accident requirements of secondary loop,anti-skip mechanism design of circuit breaker must adopt anti-skip circuit within the breaker.Based on operating principle of the anti-skip loop of circuit breaker,two de-fects in circuit breaker of Qagan Us hydro-power station are used as examples to propose improved measures.

  4. Numerical Prediction on the Thermal Interrupting Capability of HV SF6 Gas Circuit Breakers%Numerical Prediction on the Thermal Interrupting Capability of HV SF6Gas Circuit Breakers

    Institute of Scientific and Technical Information of China (English)

    MU Jingwei; GUO Jin; DENG Xiang'e

    2013-01-01

    The design technology for HV SF6 gas circuit breakers is very demanding.A numerical method for prediction of the thermal interruption capability of SF6 gas circuit breakers is established based on the two-dimensional magneto-hydrodynamic (MHD) model and a commercial CFD(computational fluid dynamics) software,FLUENT.Nozzle ablation effect is considered by introducing an independent mass conservation equation for the ablated material to the overall conservation equations of mass,momentum,and energy.The ohmic heating and the radiation of the electric arc are considered in the model by adding relevant source terms.To predict the thermal interruption capability,the arc conductance 200 ns before current zero is used as an indicator.The CFD model is applied for the high current arcing phase,and Mayr arc model is used near the current zero period.The arc conductance at 200 ns before current zero(G200) for various arcing periods are computed by the present method.It shows that there exist a limit of the G200.For those whose arcing periods are within the arcing window,the related G200 are below the limit,therefore result a successful current interruption,and vice versa.The validation of the developed computer simulation tool is therefore verified.The numerical prediction by the simulation tool is verified by the direct interrupting test of 550 kV gas circuit breaker (GCB).The developed computer simulation tool was applied in the design of a 550 kV GCB.Significant benefits have been achieved in terms of both the cost saving and shorten of the development cycle.

  5. 低压断路器的选型与应用%Selection and Application of Low-Voltage Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    钱金川; 贾文军

    2011-01-01

    介绍了低压断路器在配电线路、家用及类似场所负载、电动机负载的选型方法,并分析了在断路器保护功能以及不同负载特性情况下的选型策略。通过对低压断路器的合理选型,使低压断路器达到最佳的保护状态,并避免了因断路器选型不当及安装不合理而造成的安全隐患。%Introduction was made to a low-voltage circuit breaker type selection method in distribution line, household use, similar sites load and motor loads. Analysis was made to type selection strategy under circuit breaker protection function and different load characteristics conditions. Reasonable type selection of low-voltage circuit breakers enables low-voltage circuit breakers to reach optimal protection status, so as to avoid safety dangers caused by unsuitable circuit breaker type selection and unreasonable installation.

  6. Technical-economic evaluation of the utilization of closing resistor in CEMIG extra-high voltage circuit breakers

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, Angelica C.O.; Pinto, Roberto del Giudice R.; Teixeira, Jose Cleber; Fonseca, Rodrigo Assuncao; F. Junior, Sebastiao V. [Companhia Energetica de Minas Gerais (CEMIG), Belo Horizonte, MG (Brazil)

    1994-12-31

    This paper presents the technical and economic studies performed by CEMIG, Companhia Energetica de Minas Gerais, Brazil, concerning the use of closing resistor in its extra-high voltage (EHV) breakers. The analysis emphasizes the advantages which could be achieved with the elimination of the resistor as far as costs and reliability are concerned. This evaluation was motivated by two 500 kV breaker failures resulting from the breakdown of the closing resistor operation mechanism. These occurrences resulted in operative restriction for CEMIG EHV system. The analysis demanded a review of the capability criteria of silicon carbide (Si C) gap arresters, which are still greatly used in CEMIG EHV System, and of the procedures to be applied when carrying out the transient studies. The investigation resulted in the prompt removal of closing resistors from circuit breakers in CEMIG extra-high voltage system generating an economy of approximately U$ 840,00 and an improvement in safety and system reliability. (author) 13 refs., 4 figs., 1 tab.

  7. Feasibility analysis of a novel hybrid-type superconducting circuit breaker in multi-terminal HVDC networks

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Umer Amir [Hanyang University, Sa-3dong, Sangrok-gu, Ansan 426-791 (Korea, Republic of); National University of Sciences and Technology, PNEC Campus, Habib Rehmatullah Road, Karachi (Pakistan); Lee, Jong-Geon; Seo, In-Jin [Hanyang University, Sa-3dong, Sangrok-gu, Ansan 426-791 (Korea, Republic of); Amir, Faisal [National University of Sciences and Technology, PNEC Campus, Habib Rehmatullah Road, Karachi (Pakistan); Lee, Bang-Wook, E-mail: bangwook@hanyang.ac.kr [Hanyang University, Sa-3dong, Sangrok-gu, Ansan 426-791 (Korea, Republic of)

    2015-11-15

    Highlights: • A novel hybrid-type superconducting circuit breaker (SDCCB) is proposed. • SDCCB has SFCL located in the main current path to limit the fault current until the final trip signal. • SFCL in SDCCB suppressed the fast rising DC fault current for a predefined time. • SFCL significantly reduced the DC current breaking stress on SDCCB components. • SDCCB isolated the HVDC faulty line in three, four, and five converter stations MTDC. - Abstract: Voltage source converter-based HVDC systems (VSC-HVDC) are a better alternative than conventional thyristor-based HVDC systems, especially for developing multi-terminal HVDC systems (MTDC). However, one of the key obstacles in developing MTDC is the absence of an adequate protection system that can quickly detect faults, locate the faulty line and trip the HVDC circuit breakers (DCCBs) to interrupt the DC fault current. In this paper, a novel hybrid-type superconducting circuit breaker (SDCCB) is proposed and feasibility analyses of its application in MTDC are presented. The SDCCB has a superconducting fault current limiter (SFCL) located in the main current path to limit fault currents until the final trip signal is received. After the trip signal the IGBT located in the main line commutates the current into a parallel line where DC current is forced to zero by the combination of IGBTs and surge arresters. Fault simulations for three-, four- and five-terminal MTDC were performed and SDCCB performance was evaluated in these MTDC. Passive current limitation by SFCL caused a significant reduction of fault current interruption stress in the SDCCB. It was observed that the DC current could change direction in MTDC after a fault and the SDCCB was modified to break the DC current in both the forward and reverse directions. The simulation results suggest that the proposed SDCCB could successfully suppress the DC fault current, cause a timely interruption, and isolate the faulty HVDC line in MTDC.

  8. Approach for electrodynamic force for compensation in low voltage circuit breaker WP 630-1.2 type

    Institute of Scientific and Technical Information of China (English)

    LU Na; XU L.J.; Miedzi(n)ski B.

    2007-01-01

    Undesirable repulsive force between contact members due to both a current path shrink near a real contact area and/or so-called pinch effect is particularly onerous for power switch applications, and results in either contact floating or bouncing which are associated with an electric arc following contact welding. This problem is of great importance for any circuit breaker especially for compact low voltage vacuum circuit breakers. To avoid contact floating at closure and during any inrush current under short circuit conditions, the electrodynamic repulsive force can be employed successfully if we use a special compensation system flexibly combined with the contact itself. However to select and design the compensation system properly, its efficiency has to be known. This paper presents an approach to obtain the electrodynamic force value depending on different shaped (rectangular,square, circle and arch) copper plates used in the compensator by using ANSYS for current values 40 kA RMS. Curve-fitting was done according to the calculating results, the optimization designing of compensation unit is based on them.

  9. Transient Recovery Voltages at the Main 132kV Line Bay GIS Circuit Breaker in a Windfarm

    OpenAIRE

    Arana Aristi, Iván; Okholm, J.; Holbøll, Joachim

    2011-01-01

    This paper presents the results of investigations of the Transient Recovery Voltage (TRV) across the terminals of the main 132kV Line Bay GIS circuit breaker (GIS CB) for Walney 2, second phase of the Walney Offshore Wind Farm. Several simulations were performed where the influence of different parameters in the network was evaluated during a fault in the onshore substation. The rate of rise of recovery voltage (RRRV) and the maximum crest voltage (Uc) of the TRV across the GIS CB were compar...

  10. Transient Recovery Voltages at the Main 132kV Line Bay GIS Circuit Breaker in a Windfarm

    DEFF Research Database (Denmark)

    Arana Aristi, Iván; Okholm, J.; Holbøll, Joachim

    2011-01-01

    This paper presents the results of investigations of the Transient Recovery Voltage (TRV) across the terminals of the main 132kV Line Bay GIS circuit breaker (GIS CB) for Walney 2, second phase of the Walney Offshore Wind Farm. Several simulations were performed where the influence of different...... performed by means of time domain simulations using the EMT software PSCAD/HVDC. Based on the results, it was concluded that the highest RRRV appears on a system without additional stray capacitances, and the highest Uc appears when the fault is a single phase to ground....

  11. Simulation of the Process of Arc Energy-Effect in High Voltage Auto-Expansion SF6 Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    Rong Mingzhe; Yang Qian; Fan Chunduo

    2005-01-01

    A new magnetic hydro-dynamics (MHD) model of arc in H.V. auto-expansion SF6circuit breaker that takes into consideration nozzle ablation due to both radiation and thermal conduction is presented in this paper. The effect of PTFE (polytetrafluorethylene) vapor is considered in the mass, momentum and energy conservation equations of the constructed model. Then,the gas flow fields with and without conduction considered are simulated. By comparing the aforementioned two results, it is indicated that the arc's maximal temperature with conduction considered is 90 percent of that without considering conduction.

  12. Transient Studies in Large Offshore Wind Farms, Tak-ing Into Account Network/Circuit Breaker Interaction

    DEFF Research Database (Denmark)

    Glasdam, Jakob; Bak, Claus Leth; Hjerrild, Jesper

    2011-01-01

    to ensure reliable switching operations. Transient measurement results in an OWF are compared with simulation results in PSCAD EMTDC and DigSILENT Power Factory, where a user-defined model of the vacuum circuit breaker (VCB) is included, capable of simulating multiple prestrikes during the closing operation....... An analysis of the switching transients that might occur in an OWF will be made on basis of the validated model and the importance of the inclusion of a sufficient accurate representation of the VCB in the simulation tool will be described. The inclusion of the VCB model in PSCAD greatly improves...

  13. Dynamic Stability Analysis and Comparison between Single and Double Breakers of Air Circuit Breaker%双断点与单断点万能式断路器电动稳定性的分析与对比

    Institute of Scientific and Technical Information of China (English)

    陈德桂

    2009-01-01

    提出了一种新型双断点万能式断路器.以两个简化的模型,在短路电流作用下,分析了双断点和单断点万能式断路器触头上的电动斥力,对比了双断点和单断点万能式断路器触头上的电动稳定性,说明了双断点结构具有高电动稳定性的原因.指出提高操作机构的机械强度是双断点万能式断路器设计的关键.%A new dual-breaker air circuit breaker(ACB)was proposed.With two simplified model suffering the effect of short circuit current,the dynamic repulsion force acted on contact in ACB with single and double breakers were analyzed and compared.The reason that dual-breaker configuration had higher dynamic stability was explained as well.The key design of ACB is to impmve the mechanical strength of operation mechanism.

  14. Feasibility analysis of a novel hybrid-type superconducting circuit breaker in multi-terminal HVDC networks

    Science.gov (United States)

    Khan, Umer Amir; Lee, Jong-Geon; Seo, In-Jin; Amir, Faisal; Lee, Bang-Wook

    2015-11-01

    Voltage source converter-based HVDC systems (VSC-HVDC) are a better alternative than conventional thyristor-based HVDC systems, especially for developing multi-terminal HVDC systems (MTDC). However, one of the key obstacles in developing MTDC is the absence of an adequate protection system that can quickly detect faults, locate the faulty line and trip the HVDC circuit breakers (DCCBs) to interrupt the DC fault current. In this paper, a novel hybrid-type superconducting circuit breaker (SDCCB) is proposed and feasibility analyses of its application in MTDC are presented. The SDCCB has a superconducting fault current limiter (SFCL) located in the main current path to limit fault currents until the final trip signal is received. After the trip signal the IGBT located in the main line commutates the current into a parallel line where DC current is forced to zero by the combination of IGBTs and surge arresters. Fault simulations for three-, four- and five-terminal MTDC were performed and SDCCB performance was evaluated in these MTDC. Passive current limitation by SFCL caused a significant reduction of fault current interruption stress in the SDCCB. It was observed that the DC current could change direction in MTDC after a fault and the SDCCB was modified to break the DC current in both the forward and reverse directions. The simulation results suggest that the proposed SDCCB could successfully suppress the DC fault current, cause a timely interruption, and isolate the faulty HVDC line in MTDC.

  15. 浅谈消防风机保护断路器的整定%Setting Research of Protection Circuit Breaker for Fire Fighting Blower

    Institute of Scientific and Technical Information of China (English)

    张振国

    2014-01-01

    The setting problems of corresponding-level protection circuit breaker and the upper-level protection circuit breaker were discussed in a fire fighting blower.Through an instance,it pointed out that the corresponding-level protection circuit breaker only need the short circuit protection setting,and the upper-level protection circuit breaker need the load protection.It could provide references for the designs of similar fire fighting blowers.%针对消防风机的本级保护断路器以及上一级保护断路器的整定问题进行了探讨。通过实例,指出消防风机的本级保护断路器只设短路保护,而上一级保护器需设过负荷保护,以期为类似消防风机设计提供参考。

  16. Analysis to Differences of Miniature Circuit Breakers Between EN and IEC Standard%解析小型断路器EN与IEC标准的差异

    Institute of Scientific and Technical Information of China (English)

    章晓艳

    2012-01-01

      Analysis and comparison were carried out for EN and IEC standard about circuit breakers for over-current protection used for household and similar site──circuit breakers for AC operation (miniature circuit breakers for short), EN 60898-1 and IEC 60898-1. In the aspects of product marking requirements, short-circuit test value quantity, tripping characteristic test of circuit breakers, energy losses clas-sification, this paper gave contents of main differences so as to provide references for related technical personnel.%  对欧盟、IEC 关于家用和类似场所用过电流保护断路器——用于交流的断路器(简称小型断路器)的标准 EN 60898-1、IEC 60898-1进行了分析比较,在产品标志要求、短路试验中试验量、断路器的脱扣特性试验、能耗等级分类等方面给出了主要差异内容,以供相关技术人员进行参考。

  17. Discussion and Analysis on Common Mistakes in LV Circuit Breaker Type Selection%低压断路器选型误区探析

    Institute of Scientific and Technical Information of China (English)

    王殿光

    2016-01-01

    There are various LV circuit breakers with different manufacturers, specifications and models available in the market. Regarding circuit breaker selection and using, there are some common mistakes of users that influence the actual effect. At best, such mistakes result in malfunction and movement resistance; at worst, they lead to life and property loss. From the aspect of product standard, issues like several common mistakes in LV circuit breaker selection: understanding and selection of parameters like Icu, Ics and Icw of LV circuit breaker; relationship between LV circuit breaker’s utilization category and full selective coordination; full and partial selective protections of circuit breakers in series; influence of circuit breaker’s trip value on selective coordination;let-though energy of LV circuit breaker and function of current limiting circuit breaker are illustrated. Suggestions are proposed on the basis of analysis.%市场上低压断路器的制造商众多,规格、型号各异。用户在选择使用断路器上还存在一些误区影响了实际使用效果,轻者误动拒动、重者遭受财产损失危及生命。文章试图从产品标准着眼解释几个主要对低压断路器选择认识的误区:如何理解和选择低压断路器的Ic u、 Ic s、 Ic w等参数,低压断路器的使用类别与全选择性配合的关系,串联断路器间的全选择性和局部选择性保护,断路器脱扣值的误差对选择性配合的影响,低压断路器的允通能量及限流型断路器的作用等,并在分析的基础上给出作者的建议。

  18. Test and Maintain of 10 kV Vacuum Circuit Breaker%10 kV真空断路器的试验及维护

    Institute of Scientific and Technical Information of China (English)

    曾豪

    2015-01-01

    The vacuum circuit breaker has a simple structure, less failure characteristics, and with a strong insulation and interrupter ability, has been widely used. To illustrate the test 10 k vacuum circuit breaker and maintenance issues to our power stations a # generator circuit breakers, for example, on the 10 kV vacuum circuit breaker testing and maintenance of content analysis and exploration.%真空断路器具有结构简单、故障少的特点,且具备强大的绝缘性能和灭弧能力,得到了广泛应用。为了阐述10 kV真空断路器的试验和维护问题,以我公司发电站1#发电机出口断路器为例,对10 kV真空断路器的试验和维护内容进行了分析和探究。

  19. 浅议断路器三相不一致保护%Discuss the Three-phase Circuit Breaker Protection is Inconsistent

    Institute of Scientific and Technical Information of China (English)

    郑锡东

    2014-01-01

    出于供电可靠性考虑,现在220 kV及以上电压等级的电网普遍采用分相操作的断路器。但在实际的电网运行中,由于断路器偷跳和保护没有启动等原因,可能导致断路器三相不一致的现象出现。针对以上问题,详细分析了断路器三相不一致保护的工作原理,并在此基础上给出了处理方法。%For reliability reasons, and now more than 220 kV voltage level of the power grid and widely used circuit breaker phase operation. But in the actual operation of the grid, because the circuit breaker tripping and protection does not start other reasons, could result in a three-phase circuit breaker inconsistent phenomenon. To solve the above problems, detailed analysis of the three-phase circuit breaker inconsistent protection works, give the treatment on this basis.

  20. Characteristic of Oscillation Circuit in HVDC Circuit Breakers%高压直流断路器振荡回路特性

    Institute of Scientific and Technical Information of China (English)

    马元社; 李宾宾; 王蔚华; 李璐

    2011-01-01

    无源直流断路器常用于高压直流输电工程换流站直流场上。为了研究高压直流断路器振荡回路特性,以寻求最佳的参数配置,分析了L、C参数对直流开断的影响,给出了工程中开断电流的计算公式、额定连续过负荷直流电流的取值方法以及直流断路器组成元件的主要应力,并结合实际直流工程数据加以仿真验证,定性给出的直流断路器主要参数随L、C参数变化的规律。%DC circuit breaker is one of the important devices in the DC yard of converter stations. Analyzing the effect of L, C parameters on DC interrupting, this paper deduces the calculation formula of interrupting current for projects, and gives the method to determine the values of rated continuous overload DC current and the main stress of constituent elements in DC circuit breaker with simulations on the project data for verification.

  1. 地铁DC1500V磁保持断路器的研究%Study on Metro DC1500V Magnetic Latching Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    肖涛古; 罗雄

    2016-01-01

    The paper mainly introduces the current domestic MTR 1500V DC circuit breaker structure and working principle, focuses on the analysis and comparison of the switching process of the electric and magnetic latching circuit breaker and arc extinguishing principles. It also makes comparison of performance features the two different circuit breaker, including open and close current parameters, and open and close time analysis etc. The advantages and disadvantages of two kinds of circuit breakers are analyzed and summarized from the aspects of different structure principle and performance parameters. It provides guidance and signifi cance to the selection of future DC circuit breaker, and its maintenance.%主要介绍目前国内地铁采用的1500 V直流断路器的结构及工作原理,着重分析比较了电保持断路器与磁保持断路器的分合闸过程及灭弧原理;对比2种断路器的各种性能参数,包括开断电流参数、分合闸时间分析等;从结构原理及性能参数方面的不同对2种断路器的优缺点进行了总结分析,对后续直流断路器的选型、维护使用具有指导性意义。

  2. Three-dimensional modelling of electric-arc development in a low-voltage circuit-breaker

    Energy Technology Data Exchange (ETDEWEB)

    Piqueras, L.; Henry, D.; Jeandel, D.; Scott, J. [Laboratoire de Mecanique des Fluides et d' Acoustique, CNRS/Universite de Lyon, Ecole Centrale de Lyon/Universite Lyon 1/INSA de Lyon, ECL, 36 avenue Guy de Collongue, 69134 Ecully Cedex (France); Wild, J. [Schneider Electric, 37 quai Merlin, 38050 Grenoble Cedex 9 (France)

    2008-09-15

    This article describes direct numerical simulation of the first three milliseconds following ignition of the arc in a low-voltage circuit-breaker using a computational-fluid-dynamics code adapted for electric-arc modelling. The mobile electrode is allowed for by a moving mesh. The results describe the evolution of the arc with time in terms of its detailed electrical, thermal and fluid dynamic properties. They allow the identification of several phases during the overall arc development process studied here: arc initialisation in the widening electrode gap, arc-thermal expansion, displacement of the arc towards the tip of the mobile electrode, and the beginning of commutation to the fixed electrode. (author)

  3. Numerical Analysis of the Arc Plasma in a Simplified Low-voltage Circuit Breaker Chamber with Ferromagnetic Materials

    Institute of Scientific and Technical Information of China (English)

    Wu Yi; Rong Mingzhe; Yang Qian; Hu Guangxia

    2005-01-01

    This paper is devoted to the simulation of the arc plasma in a simplified low-voltage circuit breaker chamber. Based on a group of coupled governing equations, a three-dimensional (3-D) arc plasma model is built and solved by a modified commercial code. Firstly, this paper presents a solution of the stationary state of the arc plasma and discusses the distribution of some parameters throughout the chamber. Secondly, with the ferromagnetic materials included,the balance of the stationary state is broken and a transient course is calculated. In light of the simulation results, the temperature distribution sequence, the arc motion and the plasma jet are then described and analyzed in detail.

  4. Development of distribution and subtransmission SF/sub 6/ circuit breaker and hybrid transmission interrupter. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Votta, G.A.

    1978-06-01

    This project covered the development of a new generation of SF/sub 6/ arc spinner interrupters, a 15-kV circuit breaker (distribution) using this interrupter, and investigated the feasibility of a high voltage (transmission) hybrid interrupter using the arc-spinner and a vacuum interrupter in series. The arc spinner interrupter concept uses a self-generated magnetic field to drive an arc, on a circular path in an atmosphere of SF/sub 6/ gas, to achieve interruption. Test models of the arc spinner interrupter were built and tested to determine the component requirements and arrangements necessary for the desired performance. A single-phase laboratory model of this interrupter was successfully tested up through 25 kA at 13.5 kV. Interruption of 40 kA at 13.5 kV was demonstrated; however, satisfactory performance was not obtained at significant current levels during this program when tested at higher voltages. A full-scale model of a three-phase outdoor distribution power circuit breaker rated 18 kA at 15.5 kV was built and successfully tested to standards. The hybrid interrupter concept (transmission) uses an arc spinner and a vacuum interrupter in series. The vacuum interrupter handles the high initial rate of rise of recovery voltage associated with short line faults, and the arc spinner interrupter handles the high peak transient recovery voltage. The hybrid interrupter demonstrated an ability to handle the initial high rate of rise recovery voltage but encountered dielectric failures at relatively low current levels. This feasibility investigation was limited by the unavailability of a suitable rating of vacuum interrupters and by limitations inherent to an early model arc spinner interrupter for the tests. The investigation of the hybrid was discontinued until further development of a higher voltage arc spinner interrupter could be accomplished.

  5. Influence of residual plasma drift velocity on the post-arc sheath expansion of vacuum circuit breakers

    Science.gov (United States)

    Mo, Yongpeng; Shi, Zongqian; Bai, Zhibin; Jia, Shenli; Wang, Lijun

    2016-05-01

    The residual plasma in the inter-contact region of a vacuum circuit breaker moves towards the post-arc cathode at current zero, because the residual plasma mainly comes from the cathode spots during the arc burning process. In the most previous theoretical researches on the post-arc sheath expansion process of vacuum circuit breakers, only the thermal motion of residual plasma was taken into consideration. Alternately, the residual plasma was even assumed to be static at the moment of current zero in some simplified models. However, the influence of residual plasma drift velocity at current zero on the post-arc sheath expansion process was rarely investigated. In this paper, this effect is investigated by a one-dimensional particle-in-cell model. Simulation results indicate that the sheath expands slower with higher residual plasma drift velocity in the initial sheath expansion stage. However, with the increase of residual plasma drift velocity, the overall plasma density in the inter-contact region decreases faster, and the sheath expansion velocity increases earlier. Consequently, as a whole, it needs shorter time to expel the residual plasma from the inter-contact region. Furthermore, if the residual plasma drift velocity is high enough, the sheath expansion process ceases before it develops to the post-arc anode. Besides, the influence of the collisions between charges and neutrals is investigated as well in terms of the density of metal vapor. It shows that the residual plasma drift velocity takes remarkable effect only if the density of the metal vapor is relatively low, which corresponds to the circumstance of low-current interruptions.

  6. 关于真空断路器可靠性标志的讨论%DISCUSSION ON THE RELIABILITY CRITERION OF VACUUM CIRCUIT BREAKER

    Institute of Scientific and Technical Information of China (English)

    胡亮

    2001-01-01

    Through the discussion on the general requirements and thereliability criterion of vacuum circuit breaker, this paper puts forward a method of prediction, assessment and control for vacuum circuit breaker’s reliability, which may be effective both to the purchaser and the supplier of a vacuum circuit breaker.%通过对真空断路器可靠性的基本要求和判断标志的论述,提出了对真空断路器的使用者和制造者都有效的,对真空断路器可靠性的预测、判定和控制的方法。

  7. 大容量发电机出口断路器选择%Circuit Breakers Selection Method for Large-capacity AC High-voltage Generator

    Institute of Scientific and Technical Information of China (English)

    张爽

    2011-01-01

    针对大容量发电机出口断路器的选择问题,依据GB/T 14824-2008、IEEE Std C37.013-1997和IEC 60909-0-2001中的计算方法,并结合发电机出口断路器型式试验报告的有关数据,以某百万千瓦级发电机组为例进行了比较计算,分析计算结果,提出了对发电机出口短路器短路电流开断能力不能采用百分比而应采用绝对值进行校验.%For selecting large-capacity AC high-voltage generator circuit breakers in a large generator system, comparative calculations are conducted for a million kilowatts rated generator following the standards of GB/T 14824-2008, IEEE Std C37.013-1997 and IEC 60909-0-2001. The calculation results and the test reports of generator circuit breakers are analyzed, and a suggestion is hence offered that absolute value of short-circuit current should be used for examining the short-circuit current breaking capacity of an AC high-voltage generator circuit breaker instead of percentage value.

  8. Analysis and Solution for Causes of Simultaneous Tripping of Upstream and Downstream Circuit Breaker%两级断路器同时跳闸的原因分析及解决办法

    Institute of Scientific and Technical Information of China (English)

    李桢

    2016-01-01

    针对PLC柜上下两级断路器同时跳闸的问题,对上下两级断路器的特性进行了分析,利用断路器的脱扣曲线找到了问题原因,给出了解决的办法,并对上下两级断路器的设计提出了建议。%Aiming at the problem of simultaneous tripping of upstream and downstream circuit breaker in power supply System for PLC,analyze the character of upstream and downstream circuit breaker,find the cause of the problem with circuit breaker tripping curves, gives the solution, and the design proposal of upstream and downstream circuit breaker were put forward.

  9. Application of Fast Vacuum Circuit Breaker in Electric System%快速真空断路器在电力系统中的应用

    Institute of Scientific and Technical Information of China (English)

    艾绍贵; 马奎; 吴旭涛; 孙丽琼

    2016-01-01

    介绍了涡流驱动型快速真空断路器的原理,分析了目前配网消弧消谐、故障选线及触电防护、电网短路电流限制、串联补偿及变压器直流偏磁抑制等技术的现状和存在的问题。根据快速真空断路器特点,提出了解决相关技术问题的方法,阐述了相关装置的结构、试验及应用情况,并对快速真空断路器在电力系统中的应用进行了展望。%Introduction was made to the principle of eddy current forced fast vacuum circuit breaker. Analysis was made to the technolo-gies used and problems existing including arc and resonance elimination, fault line selection and electric shock protection, grid short-circuit current limitation, series compensation and transformer direct current magnetic bias suppression etc technologies in distribution network at present. According to the characteristic of fast vacuum circuit breaker, the solution method of those problems was proposed. This paper ex-pounded the structure, experiment and application of the relevant device. The further application of the circuit breaker is prospected.

  10. Breaker Control Circuit Unusual Processing and Analysis%一起断路器控制回路异常的处理及分析

    Institute of Scientific and Technical Information of China (English)

    陈月卿; 虞俊峰

    2012-01-01

    Introduced 220kV the Simens circuit breaker simultaneously appears two group of circuit breaker control power source in the movement to short-circuit one after another the trip unusual situation,has made the detailed analysis to its emergency processing and the unusual reason,points out the circuit breaker factory because in the product design is not standard,has brought the serious hidden danger for the production movement,this question proposes the corresponding improvement measure.%介绍了220kV西门子断路器在运行中同时出现两组断路器控制电源相继短路跳闸的异常情况,对其应急处理和异常原因做了详细的分析,指出断路器厂家由于产品设计上的不规范,给生产运行带来了严重隐患,就此问题提出相应的改进措施。

  11. Field Experiments on 10 kV Switching Shunt Capacitor Banks Using Ordinary and Phase-Controlled Vacuum Circuit Breakers

    Directory of Open Access Journals (Sweden)

    Wenxia Sima

    2016-01-01

    Full Text Available During the switching on/off of shunt capacitor banks in substations, vacuum circuit breakers (VCBs are required to switch off or to switch on the capacitive current. Therefore, the VCBs have to be operated under a harsh condition to ensure the reliability of the equipment. This study presents a complete comparison study of ordinary and phase-controlled VCBs on switching 10 kV shunt capacitor banks. An analytical analysis for switching 10 kV shunt capacitor banks is presented on the basis of a reduced circuit with an ungrounded neutral. A phase selection strategy for VCBs to switch 10 kV shunt capacitor banks is proposed. Switching on current waveforms and switching off overvoltage waveforms with, and without, phase selection were measured and discussed by field experiments in a 110 kV substation in Chongqing, China. Results show that the operation of phase-controlled VCBs for 10 kV switching shunt capacitor banks is stable, and phase-controlled VCBs can be used to implement the 10 kV switching on/off shunt capacitor banks to limit the transient overvoltage and overcurrent. The values of overvoltage and inrush current using phase-controlled VCBs are all below those with ordinary VCBs.

  12. Analysis of common faults of VS1 circuit breaker%VS1断路器常见故障分析

    Institute of Scientific and Technical Information of China (English)

    石巧莉

    2016-01-01

    In thispaper,combined with the actual situation,VS1 circuit breaker in the running process of the perennial failure and treatment measures are analyzed,hope that through this study to better enhance the operation quality of VS1 circuit breaker will be helpful.%本文主要结合实际情况,就VS1断路器运行过程中常年的故障和处理措施进行了分析,希望通过本次研究对更好提升VS1断路器运行质量有一定助益。

  13. Numerical study of turbulence-influence mechanism on arc characteristics in an air direct current circuit breaker

    Science.gov (United States)

    Wu, Mingliang; Yang, Fei; Rong, Mingzhe; Wu, Yi; Qi, Yang; Cui, Yufei; Liu, Zirui; Guo, Anxiang

    2016-04-01

    This paper focuses on the numerical investigation of arc characteristics in an air direct current circuit breaker (air DCCB). Using magneto-hydrodynamics (MHD) theory, 3D laminar model and turbulence model are constructed and calculated. The standard k-epsilon model is utilized to consider the turbulence effect in the arc chamber of the DCCB. Several important phenomena are found: the arc column in the turbulence-model case is more extensive, moves much more slowly than the counterpart in the laminar-model case, and shows stagnation at the entrance of the chamber, unlike in the laminar-model case. Moreover, the arc voltage in the turbulence-model case is much lower than in the laminar-model case. However, the results in the turbulence-model case show a much better agreement with the results of the breaking experiments under DC condition than in the laminar-model case, which is contradictory to the previous conclusions from the arc researches of both the low-voltage circuit breaker and the sulfur hexafluoride (SF6) nozzle. First, in the previous air-arc research of the low-voltage circuit breaker, it is assumed that the air plasma inside the chamber is in the state of laminar, and the laminar-model application gives quite satisfactory results compared with the experiments, while in this paper, the laminar-model application works badly. Second, the turbulence-model application in the arc research of the SF6-nozzle performs much better and gives higher arc voltage than the laminar-model application does, whereas in this paper, the turbulence-model application predicts lower arc voltage than the laminar-model application does. Based on the analysis of simulation results in detail, the mechanism of the above phenomena is revealed. The transport coefficients are strongly changed by turbulence, which will enhance the arc diffusion and make the arc volume much larger. Consequently, the arc appearance and the distribution of Lorentz force in the turbulence-model case

  14. 小型断路器操作机构的动作可靠性分析%Action Reliability Analysis of Operating Mechanism in Miniature Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    陈文华; 张文; 潘骏; 张廷秀; 陈丽丽

    2015-01-01

    The operating mechanism action reliability of miniature circuit breaker was studied.The action reliability of miniature circuit breaker was investigated and the mechanism action reliability model was built at the overload breaking moment by using Monte Carlo method of mechanism reliabilG ity design theory.Meanwhile,the action reliability sensitivity of mechanism was analyzed,which gave out the variation laws of random parameters reliability sensitivity and the impacts of random parameG ter changes to operating mechanism action reliability.The analytical results indicate that the method used herein can analyze action reliability of miniature circuit breaker operating mechanism effectively and provide a basis for the design of miniature circuit breaker operating mechanism as well.%对小型断路器操作机构的动作可靠性灵敏度进行探讨。运用机构可靠性设计理论中的Monte Carlo 法分析了操作机构在过载分断时的动作可靠性,构建了操作机构在过载分断时的动作可靠性模型;同时,利用 Monte Carlo 法分析了操作机构的动作可靠性灵敏度,给出了操作机构随机参数可靠性灵敏度的变化规律,研究了随机参数的改变对操作机构动作可靠性的影响。结果表明,该方法能够有效地分析小型断路器操作机构的动作可靠性,同时也可为小型断路器操作机构的可靠性设计提供参考。

  15. 断路器跳位监视与防跳回路的分析与改进%Analysis and Improvement on Open-Position Monitoring and Anti-Pumping Circuit of Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    叶晴炜

    2015-01-01

    某变电站252 kV SF6瓷柱式断路器防跳回路因设计缺陷使断路器跳位监视回路存在寄生回路,导致操作箱对断路器的跳位监视发生错误。分析了防跳回路对跳位监视回路的影响,并对比了550 kV H-GIS断路器出现的类似问题。阐述了成因和解决方法,对防跳回路的设计提出了改进,在跳位监视回路中串联断路器常闭辅助节点和就地防跳继电器的常闭节点,以解决寄生回路对跳位监视的影响。%The anti-pumping circuit of a 252 kV SF6 circuit breaker used in a certain substation existed parasitic circuits in its open-position circuit because of design deficiency, which caused the operation box to make mistakes towards the open-position monitoring of the circuit breaker. This paper analyzed the effect of the anti-pumping circuit on the open-position monitoring circuit, and compared with a similar phe-nomenon that happened to the 550 kV H-GIS circuit breaker. The factor and solution has been explained, and it has also proposed improve-ment towards the design of the anti-pumping circuit. In the open-position monitoring circuit, the normally closed auxiliary nodal point of the circuit breaker was connected in series to the normally closed nodal point in in-site anti-pumping relay of the circuit breaker to remove the effect of parasitic circuits on open-position monitoring.

  16. 高压真空断路器的检修与维护%Maintenance of High Voltage Vacuum Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    Vacuum circuit breaker has advantages of large capacity, good arc extin-guishing performance, long life of contact head, a small amount of operation maintenance and long maintenance cycle. Therefore, the vacuum circuit breaker has been widely used in every substation of Jigang Group Co., Ltd. The problems in maintenance of the vacuum circuit breaker are analyzed, and the improvement suggestions and measures are offered.%  真空断路器具有开断容量大、灭弧性能好、触头寿命长、运行维护量小、检修周期长等特点。因此,真空断路器在济钢各个变电站得到了广泛的应用。针对济钢内部真空断路器维护检修中出现的一些问题进行分析,并提出改进建议和措施。

  17. Analysis of common faults of VS1 circuit breaker%VS1断路器常见故障分析

    Institute of Scientific and Technical Information of China (English)

    张崇金

    2016-01-01

    With thedevelopment of power industry,the frequency of high voltage switch cabinet is more and more high.The use of VS1 circuit breaker has a very important role in the operation of high voltage switch cabinet.Based on the control principle of VS1 circuit breaker, this paper analyzes the common faults of VS1 circuit breaker,and puts forward the measures to deal with it.%随着电力行业的不断发展,高压开关柜的使用频率越来越高。而VS1断路器的使用情况对于高压开关柜的运行具有至关重要的作用。本文从VS1断路器的控制原理出发,对VS1断路器的常见故障进行分析,同时提出处理措施。

  18. AUTOMATED ANALYSIS OF BREAKERS

    Directory of Open Access Journals (Sweden)

    E. M. Farhadzade

    2014-01-01

    Full Text Available Breakers relate to Electric Power Systems’ equipment, the reliability of which influence, to a great extend, on reliability of Power Plants. In particular, the breakers determine structural reliability of switchgear circuit of Power Stations and network substations. Failure in short-circuit switching off by breaker with further failure of reservation unit or system of long-distance protection lead quite often to system emergency.The problem of breakers’ reliability improvement and the reduction of maintenance expenses is becoming ever more urgent in conditions of systematic increasing of maintenance cost and repair expenses of oil circuit and air-break circuit breakers. The main direction of this problem solution is the improvement of diagnostic control methods and organization of on-condition maintenance. But this demands to use a great amount of statistic information about nameplate data of breakers and their operating conditions, about their failures, testing and repairing, advanced developments (software of computer technologies and specific automated information system (AIS.The new AIS with AISV logo was developed at the department: “Reliability of power equipment” of AzRDSI of Energy. The main features of AISV are:· to provide the security and data base accuracy;· to carry out systematic control of breakers conformity with operating conditions;· to make the estimation of individual  reliability’s value and characteristics of its changing for given combination of characteristics variety;· to provide personnel, who is responsible for technical maintenance of breakers, not only with information but also with methodological support, including recommendations for the given problem solving  and advanced methods for its realization.

  19. 断路器“远方/就地”切换控制回路设计缺陷与改进措施%Circuit breaker"remote/local"switching control circuit design defects and improvement measures

    Institute of Scientific and Technical Information of China (English)

    樊国强; 赵红艳

    2014-01-01

    断路器作用是用来断开或接通电路,是变电所以及发电厂的一种重要电气设备,它能够在电力系统发生短路故障时迅速切除故障点。在影响断路器工作性能的因素中,除了自身电气、绝缘、机械等因素外,断路器控制、保护以及二次回路接线是否合理完善等都与其工作性能有很大关系。文章对变电站中所遇到的断路器控制回路经常出现的问题及原因进行分析,并提出相应的改进方法,这些改进方法在工程实际中经过验证是可行的。%The circuit breaker is in power plant and substation is one of the important electrical equipment,used to connect or disconnect the circuit, especially in short circuit fault occurs in the power system,the circuit breaker moves quickly will point of failure removed,the circuit breaker performance besides itself,machinery,electrical insulation,but also its control two,protection and secondary circuit wiring is perfect and reasonable have great relations.Analyzes the problems and reasons of the encountered in substation control circuit of breaker often appear,and brings forward the corresponding improvement method, the improved method in practical engineering is feasible after verification.

  20. Simulation of the Arc Behavior in Puffer-type High Voltage Circuit Breaker Considering the Influence of Nozzle Ablation

    Institute of Scientific and Technical Information of China (English)

    JIANG Xu; ZHONG Jianying; ZHANG Youpeng; ZHANG Gaochao; LI Xingwen; JIA Shenli

    2013-01-01

    In order to investigate the influence of nozzle ablation to arc,a 2 D axisymmetric magneto-hydro-dynamics arc model is developed to simulate the arc behavior during the whole interruption process in a puffer type high voltage circuit breaker,considering the nozzle ablating and the mixing process of Polytetrafluoroethylene(PTFE) vapor with SF6.The results show that the arc radius firstly increases and then decreases as arc current varies according to its sinusoida waveform.At 3.5 ms after arc initiation the nozzle ablation starts,and 2.5 ms later the current nearly reaches its peak value and nozzle ablation develops intensely.Meanwhile the nozzle is blocked by arc at this time and consequently the vapor concentration in nozzle reaches the highest.Then while the current decreasing and open distance increaseing the vapor concentration gradually decreases.Before current zero the extinction peak of arc voltage occurs.It indicates that the PTFE vapor enhances pressure rise in arc quenching chamber and strengthens the arc blocking effect on nozzle; the arc radius is wider and arc temperature is lower when nozzle ablation is considered.

  1. Impact of Abnormal Working Conditions on Performance of Moulded Case Circuit Breaker%特殊工作条件对塑壳断路器性能的影响

    Institute of Scientific and Technical Information of China (English)

    李林; 余意平

    2014-01-01

    Aiming at the problem of standard circuit breaker applying in abnormal working conditions, this paper took the thermal magnetic moulded case circuit breaker as an example to analyze the impacts from DC circuit, frequency and change of high above sea level on the circuit breaker performance, giving countermeasures to be taken in design and application process aiming at circuit breaker temperature rise, short circuit analysis ability and tripping action characteristics etc possible performance changes, which ensures the operation reliability of standard circuit breakers under abnormal working conditions.%针对标准型断路器应用于非正常工作条件下的问题,以热磁式塑壳断路器为例,分析了直流电路、频率及海拔高度变化对断路器性能的影响,并给出了在设计和使用过程中针对断路器温升、短路分析能力、脱扣动作特性等性能可能发生的变化所采取的应对措施,确保了标准型断路器在非正常工作条件下运行的可靠性。

  2. 电力系统直流断路器短路级差配置研究%Study on the Short Circuit Differential Configuration of DC Circuit Breaker in the Power System

    Institute of Scientific and Technical Information of China (English)

    周锋

    2011-01-01

    In power system,the requirements of selectivity and reliability on DC circuit breaker in direct power system are very high.On the basis of the short circuit differential configuration of three-sectional DC circuit breaker,this paper do the theory analyses%电力系统用直流电源系统中直流断路器的选择性、可靠性有着极高的要求。文中选取了三段式直流断路器短路级差配合进行理论分析以及试验验证,探索三段式直流断路器在实际电力系统中应用的可行性。

  3. Analysis and Improvement of Circuit Fault of Energy Storage of 110 kV Circuit Breaker%110 kV断路器储能回路故障分析与改进

    Institute of Scientific and Technical Information of China (English)

    陈飞建; 胡定林

    2014-01-01

    本文介绍了几类断路器储能回路故障现象及其危害,并通过实例,分析了北京 ABB 高压开关设备有限公司110 kV 断路器储能回路存在的缺陷,提出了合理的处理改进措施。%This paper introduces the circuit fault phenomenon and its harm of several kinds of circuit breaker in energy stor-age, and through examples, analyzes energy storage defects of 110 kv circuit breaker of Beijing ABB high voltage switch equipment Co., Ltd, and puts forward the reasonable treatment measures for improvement.

  4. Analysis and Improvement of Circuit Fault of Energy Storage of 110kv Circuit Breaker%110 kV断路器储能回路故障分析与改进

    Institute of Scientific and Technical Information of China (English)

    陈飞建; 胡定林

    2014-01-01

    本文介绍了几类断路器储能回路故障现象及其危害,并通过实例,分析了北京 ABB 高压开关设备有限公司110 kV 断路器储能回路存在的缺陷,提出了合理的处理改进措施。%This paper introduces the circuit fault phenomenon and its harm of several kinds of circuit breaker in energy sto- rage, and through examples, analyzes energy storage defects of 110kv circuit breaker of Beijing ABB high voltage switch eq- uipment Co., Ltd, and puts forward the reasonable treatment measures for improvement.

  5. Circuit-breakers: optical technologies for probing neural signals and systems.

    Science.gov (United States)

    Zhang, Feng; Aravanis, Alexander M; Adamantidis, Antoine; de Lecea, Luis; Deisseroth, Karl

    2007-08-01

    Neuropsychiatric disorders, which arise from a combination of genetic, epigenetic and environmental influences, epitomize the challenges faced in understanding the mammalian brain. Elucidation and treatment of these diseases will benefit from understanding how specific brain cell types are interconnected and signal in neural circuits. Newly developed neuroengineering tools based on two microbial opsins, channelrhodopsin-2 (ChR2) and halorhodopsin (NpHR), enable the investigation of neural circuit function with cell-type-specific, temporally accurate and reversible neuromodulation. These tools could lead to the development of precise neuromodulation technologies for animal models of disease and clinical neuropsychiatry.

  6. 用于智能配电网自动重合闸的断路器分类方法%Classification of Circuit Breakers Suitable for Auto-Reclosing in Smart Distribution System

    Institute of Scientific and Technical Information of China (English)

    丛伟; 孔瑾; 赵义术; 丁磊; 王葵

    2013-01-01

      智能配电网中的断路器类型和数量较多,为了实现合理、有序的自动重合闸,有必要研究断路器的分类方法。文章提出一种基于故障后跳闸断路器信息向量和断路器类型及关联矩阵的断路器分类方法。定义断路器跳闸信息向量描述故障发生后跳闸的断路器,定义断路器类型及关联矩阵描述断路器类型及各断路器之间的连接关系,对上述2个矩阵进行乘法运算,可对因故障隔离而动作的断路器类型进行自动区分,并能指示待重合断路器之间的连接关系,为实现预期的自动重合时序提供依据。在此基础上研究了网络结构改变、断路器拒动导致故障隔离范围扩大、关键位置的断路器状态信息缺失等异常情况对断路器分类方法的影响,提出矩阵修正方案应对各种异常情况。算例分析结果验证了所提算法的正确性和可行性。%In smart distribution network many circuit breakers in various types are equipped. To implement reasonable and ordered auto-reclosure, it is necessary to research the classification of circuit breakers. A method of circuit breaker classification for smart distribution network, which is based on the information vectors of tripped-out circuit breakers due to fault and the types of circuit breakers and corresponding incidence matrix, is proposed. The tripout information vectors of circuit breakers are defined to describe tripped-out circuit breakers due to fault, and the types of circuit breakers and corresponding incidence matrix are defined to describe the types of circuit breakers and the connection among them. By means of multiplication operation of above-mentioned two matrices, the types of tripped-out circuit breakers due to fault isolation can be automatically distinguished and the connection among circuit breakers to be auto-reclosed can be pointed out to provide the foundation for anticipative time sequence of auto

  7. STUDY OF THE INFLUENCE LEVEL CURRENT OF THE SHORT CIRCUIT ON RELIABILITY OF THE BREAKERS

    Directory of Open Access Journals (Sweden)

    Erhan F.

    2010-04-01

    Full Text Available In the article the analysis of the influence level current of the short circuit of the electrical equipment. It is designed the mathematical model allowing the modeling prototype reliability of the operation electrical equipment installed in nodes of the systems.

  8. 直流开断技术的进展与新型直流断路器%Development of Modern DC Switching Technologies and New Type of DC Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    陈德桂

    2014-01-01

    The renaissance of DC system promotes the progress of DC interruption technologies.First of all,this paper introduced the new demands for DC switches according to its application area to be expanded,then the difference between DC and AC interruption characteristics was analyzed,especially,non-stable phenomena to quenching DC arc is shown in the region of small DC current interruption.Based on the above analysis,some new DC interruption technologies and new types of DC circuit breakers were presented,including permanent magnet circuit breaker without polarity;DC circuit breaker derived from AC;gas filled DC circuit breaker;DC circuit breaker with artificial current zero produced by self-excitation oscillation circuit.%提出了直流系统对直流开断的新要求,分析了直流开断与交流分断的区别。同时介绍了几种直流开断新技术与新型直流断路器,包括无极性直流断路器、由交流派生直流断路器、密封充气式直流开关、自励振荡人工零点直流断路器,理清了直流开断技术的进展。

  9. 采用高耦合度分裂电抗器的并联型断路器均流过程研究%Current Dividing Process of Paralleled Circuit Breakers with High Coupled Split Reactor

    Institute of Scientific and Technical Information of China (English)

    袁召; 尹小根; 潘垣; 何俊佳

    2012-01-01

    Focussing on the current sharing process of the paralleled circuit breakers with a high coupled split reactor(HCSR),we put forward the expressions of imbalance current of simply paralleled circuit breakers and the paralleled circuit breakers with HCSR.Conclusions could be drawn that the current limiting reactor and coupling coefficient of HCSR and the arc resistance of the circuit breakers were main factors that affected the current sharing results.In order to prove the onclusions above,the simulation models of HCSR and vacuum/SF6circuit breakers were established to simulate the current sharing of paralleled circuit breakers,and a synthetic circuit test of paralleled circuit breakers was also conducted.The simulation and test results are consistent with the analysis conclusions.The research results give a principle to choose the parameters of HCSR under different types of circuit breakers,and can be used to guide the design of paralleled circuit breakers with HCSR.%为了研究基于高耦合度分裂电抗器(high coupled split reactor,HCSR)的并联型断路器的并联均流效果,推导了简单并联及基于HCSR的并联型断路器并联支路间不平衡电流的表达式,通过分析得出结论:HCSR单臂限流电感、双臂间耦合度、选用的断路器弧阻大小等因素是影响并联型断路器均流效果的主要因素。为验证上述结论,建立了HCSR、真空灭弧室、SF6灭弧室的电路仿真模型,开展了相关仿真分析,并采用合成回路进行了对应断路器并联开断实验。仿真、实验结果与理论分析结果相符合。基于上述研究结果,最终给出了针对不同类型并联断路器的HCSR单臂电感的选取原则,以用于指导新型并联断路器的设计。

  10. Short-Circuit Making Phase Angle and Tri-Pole Circuit-Breaker Each Pole Breaking Performance%短路合闸相角与三极断路器各极的分断性能

    Institute of Scientific and Technical Information of China (English)

    汤金华

    2012-01-01

    Starting from making phase angle of three-phase short-circuit test, this paper analyzed the different impact of making phase angle on tri-pole circuit-breaker each pole. Comparison of three-phase different rigorous degree was made from recovery voltage, let-through energy, arc energy and peak current after breaking. Due to the difference of the circuit-breaker arc blowout system, the uncertain rule existed, but the system was universally adaptable to the circuit breaker of fine arc blowout performance.%从三相短路试验的合闸相角出发,分析合闸相角对三极断路器各极不同的影响,从分断后的恢复电压、允通能量、电弧能量、峰值电流四个方面比较三相的不同严酷程度,虽然由于断路器灭弧系统性能的差异,该规律存在着不确定性,但普遍适用于灭弧性能良好的断路器。

  11. Mechanical Fault Diagnosis of High Voltage Circuit Breakers Based on Variational Mode Decomposition and Multi-Layer Classifier

    Directory of Open Access Journals (Sweden)

    Nantian Huang

    2016-11-01

    Full Text Available Mechanical fault diagnosis of high-voltage circuit breakers (HVCBs based on vibration signal analysis is one of the most significant issues in improving the reliability and reducing the outage cost for power systems. The limitation of training samples and types of machine faults in HVCBs causes the existing mechanical fault diagnostic methods to recognize new types of machine faults easily without training samples as either a normal condition or a wrong fault type. A new mechanical fault diagnosis method for HVCBs based on variational mode decomposition (VMD and multi-layer classifier (MLC is proposed to improve the accuracy of fault diagnosis. First, HVCB vibration signals during operation are measured using an acceleration sensor. Second, a VMD algorithm is used to decompose the vibration signals into several intrinsic mode functions (IMFs. The IMF matrix is divided into submatrices to compute the local singular values (LSV. The maximum singular values of each submatrix are selected as the feature vectors for fault diagnosis. Finally, a MLC composed of two one-class support vector machines (OCSVMs and a support vector machine (SVM is constructed to identify the fault type. Two layers of independent OCSVM are adopted to distinguish normal or fault conditions with known or unknown fault types, respectively. On this basis, SVM recognizes the specific fault type. Real diagnostic experiments are conducted with a real SF6 HVCB with normal and fault states. Three different faults (i.e., jam fault of the iron core, looseness of the base screw, and poor lubrication of the connecting lever are simulated in a field experiment on a real HVCB to test the feasibility of the proposed method. Results show that the classification accuracy of the new method is superior to other traditional methods.

  12. Influence of the gas flow rate on the nonchemical equilibrium N2 arc behavior in a model nozzle circuit breaker

    Science.gov (United States)

    Wu, Yi; Sun, Hao; Tanaka, Yasunori; Tomita, Kentaro; Rong, Mingzhe; Yang, Fei; Uesugi, Yoshihiko; Ishijima, Tatsuo; Wang, Xiaohua; Feng, Ying

    2016-10-01

    The influence of the gas flow rate on the N2 arc behavior was investigated based on a previously established nonchemical equilibrium (non-CE) model. This numerical non-CE model was adopted in the N2 nozzle arc in a model circuit breaker. The arc behaviors of both the arc burning and arc decay phases were obtained at different gas flow rates in both the non-CE and local thermal equilibrium (LTE) model. To better understand the influence of the gas flow rate, in this work we devised the concept of the nonequilibrium parameter. Additionally, the influences of convection, diffusion, and chemical reactions were examined separately to determine which one contributed most to the non-CE behavior. Finally, laser Thomson scattering (LTS) measurements at different gas flow rates were adopted to further demonstrate the validity of the non-CE model. The results of the macroscopic behaviors indicate that the deviations between the non-CE and LTE models during the arc burning phase are much fewer than those during the arc decay phase. By the nonequilibrium parameters, it clearly indicates that with an increase in the gas flow rate, the non-CE effect will be greatly enhanced. During the arc burning phase, this non-CE effect is mainly caused by radial diffusion of the particles. During the arc decay phase, for the charged particles, the chemical reactions had the greatest effect on the time variations of the particle number densities; however, for the neutral particles the time variations of the number densities were mutually influenced by convections, diffusions, and chemical reactions. Finally, the LTS results further demonstrate the validity of the non-CE model at different gas flow rates.

  13. Design of Generator Circuit Breaker Failure Protection for Nuclear Power Plants%核电厂发电机出口断路器失灵保护设计

    Institute of Scientific and Technical Information of China (English)

    谢创树

    2014-01-01

    核电厂发电机机端与升压变压器之间都装设发电机出口断路器,而且装设了发电机出口断路器失灵保护。文中分析核电厂发电机所配置的保护及其定值,发现发电机出口断路器失灵保护设计存在问题:某些启动跳发电机出口断路器、灭磁、关闭主汽门的电气保护,因电流判据不满足而不能直接有效地启动发电机出口断路器失灵保护;汽轮发电机组在程序跳闸过程中,发电机出口断路器发生故障而不能跳开,也不能启动发电机出口断路器失灵保护。对上述问题所造成的危害,文中提出核电厂发电机出口断路器失灵保护设计的改进措施,完善了核电厂发电机出口断路器失灵保护设计。%In a nuclear power plant,between the generator terminal and the step-up transformer,generator circuit breakers are installed,and generator circuit breaker failure protection is also installed.This paper analyzes the protections and the value settings of the nuclear power plant generator,and points out the problems in the generator circuit breaker failure protection design.First,in the protection of some j ump starter generator circuit breakers,de-excitation,and the main valve closing,as the current criteria are not satisfied,the starter generator circuit breaker failure protection cannot be directly activated. Secondly,during the turbo-generator program tripping process,the generator circuit breakers break down and cannot trip, neither can the generator circuit breaker failure protection be activated.Based on the harm caused by these problems,this paper proposes some improvements on the nuclear power plant generator breaker failure protection design,further improving the generator circuit breaker failure protection design in the nuclear power plant.

  14. 浅析500kV断路器操作箱起动失灵优缺点%Analysis of 500kV circuit breaker box start-up failure advantages and disadvantages

    Institute of Scientific and Technical Information of China (English)

    杜书平; 杨平

    2013-01-01

    This article through to XuJi ZFZ-822/A circuit breaker box start-up failure functional analysis, points out the circuit breaker box start-up failure functional advantages and disadvantages , and in the light of the shortcomings mentioned puts forward some improvement Suggestions, ensure circuit breaker failure protection correct action.%本文通过对许继 ZFZ-822/A 断路器操作箱起动失灵功能的分析,指出了操作箱起动失灵功能的优缺点,并针对所述缺点提出了改进建议,确保断路器失灵保护正确动作。

  15. 变电站断路器常见故障及检修要点分析%Analysis of Common Malfunction and Maintenance Key Points of Circuit Breaker in Substation

    Institute of Scientific and Technical Information of China (English)

    温伟

    2015-01-01

    The most important part of the circuit breaker equipment is the control circuit of the actuator and the breaker itself, and the two parts is the most prone part of the daily use. The common failures in the transformer substation circuit breakers are analyzed, and the maintenance measures are put forward for reference.%断路器设备最为重要的组成部分是操动机构和断路器本身的控制回路原件,这两部分也是日常使用过程中最易出现问题的部分。主要分析了变电站断路器中的常见故障,并提出了检修措施,以供参考。

  16. SF6高压断路器检测维护策略研究%Research on the detection and maintenance strategy of SF6 high voltage circuit breaker

    Institute of Scientific and Technical Information of China (English)

    孙勇军

    2016-01-01

    SF6高压断路器是利用六氟化硫气体作为灭弧介质和绝缘介质的一种断路器,由于SF6气体的优异性能,使其在应用过程中具备明显的优势.鉴于此,本文主要分析SF6高压断路器的检测维护策略.%SF6 high voltage circuit breaker is a circuit breaker which uses six sulfur fluoride gas as arc extinguishing media and insulating medium,which has obvious advantages in the application process because of the excellent performance of SF6 gas.In view of this,this paper mainly analyzes the SF6 high voltage circuit breaker testing and maintenance strategy.

  17. 虚拟样机技术在断路器优化中的应用研究%Application Study of Virtual Prototype Technology in Optimization of Circuit Breakers

    Institute of Scientific and Technical Information of China (English)

    于永站; 张金泉; 孙永雷; 陈大江

    2012-01-01

      以 KFW2系列万能式断路器为列,介绍了虚拟样机技术在断路器优化中的应用,利用 ADAMS软件建立断路器虚拟样机模型,对断路器的运动情况进行仿真,模拟了实物样机的真实运动情况,得到断路器各部件在分离、试验、连接位置时的行程数据,并给出了关键部件在试验和连接位置时的行程范围。通过分析结果表明,虚拟样机技术对低压断路器的优化提供了新的技术途径%  Taking KFW2 series open-construction circuit breaker as an example, this paper introduced the application of virtual prototype technology in circuit-breaker optimization. ADAMS software was used to build up a circuit-breaker virtual prototype model to carry out simulation for movement conditions of circuit breakers. The real movement conditions of actual prototype was simulated to get the travel data of circuit-breaker each component at separating, test, contact positions and travel ranges of key components at test and contact positions were given. The results of analysis show that virtual prototype technology has provided new technology path for low-voltage circuit-breaker optimization.

  18. Improvement of energy storage motor control circuit of hydraulic actuator in high-voltage circuit breakers%高压断路器液压操动机构储能电机控制回路改进

    Institute of Scientific and Technical Information of China (English)

    张全民; 赵玉柱

    2011-01-01

    高压断路器液压操动机构的常见故障是储能电机频繁启动。通过合理地设计储能电机的控制回路,减少了液压机构频繁启动的现象。%The fault of the mechanism of High voltage circuit-breaker is motor of storaging power high frequency starup.That rationally design control circuit of hydraulic mechanism reduce the fault that motor of storaging power high frequency starup.

  19. 220 kV 升压站 SF6断路器改造和应用%Transformation and Application of SF6 Circuit Breaker in 220 kV Substation

    Institute of Scientific and Technical Information of China (English)

    姚舜

    2015-01-01

    Previously the SF6 circuit breakers of ELFSP4-1 type were applied to 220 kV substation in Guangzhou Zhujiang Power Plant, which were imported from the Swiss ABB Company.Now, they are replaced by outdoor, an-tifouling three-phase mechanical linkage or three-phase electrical linkage SF6 circuit breakers which are produced by the Siemens high voltage switch Co.Ltd.in Hangzhou.The breaker’s functions and application after transfor-mation are described in detail from four kinds of circuit breaker, i.e.,the main transformer circuit breaker, the line circuit breaker, the contact circuit breaker and start /spare transformer circuit breaker.Finally, the discovery and the existing problems in the reform and operation are explained briefly.And some matters needing attention in the future are put forward in the operation and maintenance.The SF6 circuit breakers are running well in field.%广州珠江电厂220 kV升压站SF6断路器为瑞士ABB公司ELFSP4-1型产品换型改造的杭州西门子高压开关有限公司生产的户外、防污型三相机械联动型或三相电气联动型产品。从主变出口断路器、线路出口断路器、母联分段断路器和启动/备用变出口断路器四类不同断路器分别描述了断路器改造后的功能和现场应用情况,最后就改造和运行中发现和存在的问题进行了简要说明,并提出了今后维护运行中的注意事项。新改造的西门子公司SF6断路器现场运行良好。

  20. LW15-252型断路器气动回路的改进研究与实施%Improvement of Pneumatic Circuit for LW15-252 Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    郭夫; 贾明月; 刘树新; 蒋晓刚

    2011-01-01

    笔者介绍了一种关于LW15-252型断路器气动回路改进方案.在分析气动回路组成及运行原理基础上,详细研究了进口电磁阀、气水分离器结构及动作原理,改进设计了电磁阀活塞和气水分离器滤芯,解决电磁阀活塞容易断裂和气水分离器因锈蚀影响正常工作的问题.从根本上解决了气动回路故障频发的难题,提高了该型断路器稳定运行水平,同时打破了国外技术垄断,也为改造同类断路器提供了借鉴.%This paper introduced an improvement scheme for the pneumatic circuit of the LW15-252 circuit breaker. By analyzing the composition and running principle of the apneumatic circuit, we investigated the basic structures and action principles of the inlet solenoid valve and moisture separator, redesigned the piston of the valve and the filter element of the moisture separator to preven the piston from break and the moisture separator from corrosion. Thus, the frequent failures of the pneumatic circuit disappeared, and the level of stable operation of the LW15-252 circuit breaker was greatly improved. In addition, this study has broken the monopolization of the foreign technology in China, and provides a good reference for updating the similar breakers with pneumatic mechanism.

  1. 南阳特高压断路器失灵保护的研究%Study on Nanyang substation of UHV circuit breaker failure protection

    Institute of Scientific and Technical Information of China (English)

    姜自强; 刘建勇

    2015-01-01

    晋东南-南阳-荆门特高压示范工程的正式投运标识着特高压电网的建设已进入快速发展阶段,但是特高压二次系统时间常数的增大使得CT拖尾现象变得不可忽视。一方面,对特高压断路器 CT电流互感器的选型提出了新的问题,只选择TPY次级则会进一步恶化CT拖尾现象,选择P次级则增加成本。另一方面,CT拖尾对断路器失灵保护的正确动作造成了负面的影响。针对该情况,对特高压3/2断路器接线方式下断路器的失灵保护进行了研究,并提出一种针对性的改进方案。通过对比分析、仿真实验以及数模实验结果,证明该修改方案是切实可行的。既能有效地解决特高压断路器 CT电流互感器的选型问题,也能有效地解决 CT拖尾对失灵保护的危害问题。%The formal commissioning Jindongnan-Nanyang-Jingmen UHV demonstration project identifies that the construction of special high-voltage power grid has entered a rapid development stage, but the increase of UHV two system time constant makes the CT become tailing phenomenon can not be ignored. On the one hand, it puts forward a new problem for the selection of UHV circuit breaker CT current transformer, namely selecting only the TPY secondary will deteriorate further CT tailing phenomenon and selecting the P secondary will increase the cost. On the other hand, CT trailing influences breaker failure protection, making it unable to right action. In view of this situation, it studies the failure protection under the wiring mode of 3/2 breaker in UHV and proposes an improved scheme. The contrast analysis, simulation and RTDS experimental results prove that the modified scheme is feasible, which can both effectively solve the problems of the selection of UHV circuit breaker CT current transformer and CT tailing hazard failure protection.

  2. Circuit breakers for addiction.

    Science.gov (United States)

    Foy, A

    2007-05-01

    The phenomenon of addiction is complex, although its expression clinically is relatively straightforward. There is a series of neurophysiological changes that mediate changes in the mesolimbic and mesocortical systems which in turn lead to disturbances in reward mechanisms. These then act to perpetuate the cycle of intoxication and reinforcement, withdrawal, craving and compulsive use. As our understanding of the pathophysiology of this process has improved, new pharmacological agents have been developed with the potential to moderate or even reverse it. This article briefly reviews the treatment of addiction with particular reference to emerging pharmaceutical agents.

  3. 双断点塑壳断路器触头固有分断时间等计算分析与优化设计%Analysis and Optimization of Inherent Breaking Time for Two-Breakers Molded Case Circuit Breakers Contacts

    Institute of Scientific and Technical Information of China (English)

    周光照

    2016-01-01

    通过对双断点塑壳断路器触头机构的动作过程的受力与运动的详尽分析,应用SolidWorks软件创建了符合实际情况的物理模型与动力学模型,然后应用MATLAB软件,以双断点断路器触头机构相关参数如杠杆弹簧刚度、下连杆长度、动触头质量等多种参数的变化为实例进行优化设计,计算出对应的触头分断速度、固有分断时间、超行程等断路器关键技术数据,同时得到相应情况下的触点P的运动曲线图,为双断点断路器触头机构的优化设计或逆向工程提供依据和参考。%Through a detailed analysis of the force and motion of action about contact mechanism of the two-breakers molded case circuit breaker, creating a kinetic model in line with the actual situation using SolidWorks software, and then using MATLAB software, two-breakers circuit breaker contacts with institutions spring stiffness related parameters such as leverage, changes in the length of the lower link, the movable contact quality and other parameters to optimize the design for instance, calculate the corresponding contact breaking speed, inherent breaking time, travel and other ultra-breaker key technical data, at the same time the corresponding case of contact P of motion graph provide references for optimizing the design or reverse engineering double-break circuit breaker contacts institutions.

  4. Development of a HVDC prototype breaker

    Science.gov (United States)

    Damsky, B. L.; Barkan, P.; Imam, I.; Permerlani, W.; Anderson, J. M.; Carroll, J. J.; Hudson, J. E.; Pohl, R. V.; Solberg, W. D.; Sharbaugh, A. H.

    1980-06-01

    The design features of high voltage dc circuit breaker based on the commutation concept are studied. Tests of components indicate the breaker is capable of interrupting a fault current of 10 kA on a 400 kV system and absorbing up to 10 MJ of system energy without generating more than 1.6 per unit voltage on the system. Interactions of the breaker with a three terminal network were studied using a system simulator.

  5. A Scheme for Current-limiting Hybrid DC Circuit Breaker%一种限流式混合直流断路器方案

    Institute of Scientific and Technical Information of China (English)

    江道灼; 张弛; 郑欢; 叶李心; 严玉婷

    2014-01-01

    直流输电与交流输电相比,具有线损低、不存在系统同步运行稳定性问题等一系列优点。近年来,随着电压源型高压变流器等技术的迅速发展,柔性多端高压直流输电系统、直流输配电网以及直流断路器等关键技术与装备的研究受到了国内外的高度重视。文中简要阐述了机械式、全固态与混合式3类直流断路器的拓扑结构、工作原理、优缺点及国内外研究现状,指出高压直流断路器应以混合式为主要发展方向;提出一种限流式混合直流断路器方案并仿真验证了其可行性,该方案采用全/半控器件串联构成固态开关再与机械开关并联的混合开关结构及故障限流技术,可有效抑制直流短路电流上升率,降低故障判断灵敏性与机械开关速动性的要求,减少高压应用场合下固态开关器件的串联数量(特别是绝缘栅双极型晶体管等价格昂贵的全控型器件),从而降低装置工程化实现的技术难度及其体积与成本。%In contrast to alternating current(AC) power transmission,direct current(DC) power transmission has a series of advantages,such as low line loss and nonexistence of the problem of system synchronous operation stability.In recent years, with the rapid development of voltage source converter technology with higher voltage,the study on flexible multi-terminal high voltage direct current transmission(HVDC) system,DC transmission and distribution power net,as well as the related key technologies and equipments such as the high-voltage DC circuit breaker (DC-breaker) has captured great attention from the community at home and abroad.The research status of three types of DC-breakers(spoken of as the mechanical type,all-solid-state and hybrid type DC-breakers) and their topologies,working principles,advantages as well as disadvantages are briefly treated.It is concluded that the hybrid type should be the main trend of development

  6. 110 kV FXT11型SF6断路器充气阀改造%Pneumatic Valve Modification for 110 kV FXT11 SF6 Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    尚胤彤; 马雯

    2016-01-01

    由于充气阀密封性不良,大庆油田供电公司杏南工区所辖110 kV FXT11型SF6断路器频发气压异常报警事故,大大降低了断路器的灭弧能力,给电网安全运行带来了巨大隐患。原厂充气阀无法入厂大修更换,没有备品备件,为此参照35 kV LW8-35B型SF6断路器充气阀的设计原理,对FXT11型断路器充气阀进行了改造,配备新的弹簧、自封阀和密封胶垫。实践证明,改造后的新充气阀可以代替原厂的充气阀。%Owing to the sealing defects of pneumatic valve, the 110 kV FXT11 SF6 circuit breaker which belongs to Xingnan branch of power supply company transmits the signal of“Pressure Abnormity” frequently.Thus the arc extinguishing capability of this circuit break-er decreased significantly,the grid security was also threatened vastly.The original pneumat-ic valve can’ t replace when the circuit breaker is overhauling, the corresponding spare parts are insufficient. Technicians launched a pneumatic valve modification for 110 kV FXT11 SF6 circuit breaker, taking the design principle of 35kV LW8-35B SF6 circuit breaker for refer-ence. The result of actual experiment is manifested that the new pneumatic valve can substi-tute the original one.

  7. 10 kV手车式断路器底盘车检修专用工具的研制%Development of Special Device for Repairing Chassis of 10 kV Handcart Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    龚先鹤; 曹辉; 易永利; 钱碧甫

    2015-01-01

    介绍了10 kV手车式断路器底盘车闭锁结构特点及原理,根据温州地区近些年来该类设备出现的故障问题,分析了相应的底盘车故障检修处理手段,针对检修过程中存在的问题,研制了10 kV断路器底盘车检修专用工具,以此来达到现场快速检修底盘车的目的,现场应用情况表明,该装置有效解决了原先需要返厂检修的难题,减少了停电时间,降低了检修成本。%Introduction was made to the structure features and principle of chassis interlock of 10 kV handcart circuit breakers. According to the faults of circuit breakers in recent years in Wenzhou district, this paper analyzed the corresponding faults overhaul methods in chassis of circuit breakers. In allusion to the existing problems in the overhaul process, this paper developed the special device for repairing chassis of 10 kV handcart circuit breakers to fast repair the chassis of circuit breakers onsite. The onsite application condition shows that the former returned overhaul problem is solved effectively and the outage time and overhaul cost are greatly reduced.

  8. 500kV变电站220kV线路断路器延时分闸故障分析%Fault Analysis of Delay Opening of 220 kV Circuit Breaker in 500 kV Substation

    Institute of Scientific and Technical Information of China (English)

    黄玮; 胡宏宇; 陈开群; 彭军海

    2012-01-01

    In view of the importance of close-open time, taking the delay opening failure of a 220 kV circuit breaker for an example, the reason of circuit breaker B phase delay opening is tested and a comprehensive analysis is given. The test results show that there exists conversion delay of the circuit breaker B phase auxiliary switch to cause the mismatch of open-close time of circuit breaker and operation time of relay protection equipment, which affected the opening time of the circuit breaker. Therefore, it is recommended to enhance the periodic test of the close-open time in power system test pro cedure to reduce the line fault.%鉴于断路器合-分时间参数的重要性,以一起220 kV线路断路器延时分闸故障为例,对断路器B相延时分闸的原因进行了现场测试,并进行了全面分析.测试结果表明,断路器B相辅助开关转换存在延时,造成断路器合—分时间与继电保护装置动作时间配合不当,影响了断路器的分闸时间,建议在电力系统相关试验规程中加强合—分时间的周期性测试,以减少线路故障.

  9. Development and testing of a 180-volt dc electronic circuit breaker with a 335-ampere carry and 1200-ampere interrupt rating

    Science.gov (United States)

    Brush, A. S.; Phillips, R. L.

    1991-01-01

    NASA Lewis Research Center and associated contractors have conducted a program to assess the potential requirements for a high-current switch to conceptually design a switch using the best existing technology, and to build and demonstrate a breadboard which meets the requirements. The result is the high current remote bus isolator (HRBI). The HRBI is rated at 180 V dc, 335 A continuous with a 1200 A interrupt rating. It also incorporates remote-control and protective features called for by the Space Station Freedom PMAD dc test bed design. Two breadboard 335 A circuit breakers were built and tested that demonstrate a promising concept of paralleled current-limiting modules. The units incorporated all control and protective features required by advanced aerospace power systems. Component stresses in each unit were determined by design, and are consistent with a life of many thousands of fault operations.

  10. Correctly Understanding and Choosing the Current Parameter of Low-voltage Circuit Breaker%正确理解和选择低压断路器的电流参数

    Institute of Scientific and Technical Information of China (English)

    李远景

    2011-01-01

    低压断路器在配电系统中起着十分重要的作用,低压断路器保护特性的实验加深了学生对理论知识的理解,锻炼了动手能力,对此分析低压断路器的各个电流参数的概念、特性及其作用,帮助从事电气设计、采购、施工和监理工作人员正确理解断路器参数的意义和确定参数,提出更好的意见和建议.%Low-voltage circuit breaker plays a very important role in the distribution system.The experiment of low-voltage circuit breaker deepens students' understanding of theoretical knowledge and practice ability.The concept, feature and function of current parameter of low-voltage breaker are analyzed to help the staff in electrical design, procurement, construction and supervision industry correctly understand the meaning of circuit breaker and the ensuring of the parameters which better suggestions are proposed.

  11. Interruption of a dry-type transformer in no-load by a vacuum circuit-breaker

    Science.gov (United States)

    Vandenheuvel, W. M. C.; Daalder, J. E.; Boone, M. J. M.; Wilmes, L. A. H.

    1983-08-01

    Overvoltages generated during interruption of a dry type delta-star connected transformer in no load by a vacuum breaker were studied. During interruption of inrush current 37% of the phase-to-ground overvoltages were 5 pu, and 6% 7 pu. Comparison of experimental and theoretical results using Boyle's model shows no discrepancy for inrush currents and clean overvoltages from the steady-state interruption. Overvoltages due to repetitive reignitions (not covered by Boyle's model) are higher than the calculated values during steady-state switching.

  12. 高压直流输电用无源型直流转换开关电弧电流特性研究%Arc Current Characteristic of DC Circuit Breaker in HVDC Transmission and Distribution System

    Institute of Scientific and Technical Information of China (English)

    那虎; 丁正平; 孙晋峰; 杨俊清; 刘龙开; 袁芳; 洪深

    2012-01-01

    直流输变电系统用无源型高压直流转换开关是直流系统中的重要运行设备,其运行工况及工作特性极其特殊.笔者通过对高压直流转换开关工作原理及工况进行研究,并依据试验测得的断口电弧电流曲线的特征,对高压直流转换开关开断转换电流的电弧电流特性进行理论研究及分析,给出了电弧电流特性函数,指出高压直流转换开关开断的关键点是断口的弧阻小,变化率大,L1C1辅助支路频率高,才能开断较大的直流电流.%The passive high-voltage direct current (HVDC)circuit breaker is important for ensuring reliability of HVDC distribution system, and its working condition and characteristic are particular. In this paper, the working condition and characteristic of HVDC circuit breaker in HVDC transmission and distribution system are analyzed, the arc current characteristic of the breaker is investigated according to test data, and a function for describing arc current characteristic of the breaker is achieved. Conclusion is drawn that small arcing resistance, high varying rate, and high frequency of L1C1 circuit can facilitate breaking larger direct current by HVDC circuit breaker.

  13. 110 kV断路器防跳回路异常改造方案的探讨%To Investigate the Anti-tripping Circuit Breaker 110 kV Abnormal Rehabilitation Programs

    Institute of Scientific and Technical Information of China (English)

    马杰伟

    2015-01-01

    主要对110 kV断路器防跳回路异常改造方案展开了探讨,介绍了断路器本体机构防跳回路系统,并提出了回路改造的措施和方案,以期能为有关方面的需要提供参考和借鉴。%The main anti-jump to 110 kV circuit breaker abnormal transformation plan launched a discussion describes the anti-tripping circuit breaker main body systems, and made the circuit transformation measures and programs in order to provide reference for the needs of the parties concerned .

  14. 基于遗传算法的有源式高压直流开关参数计算%Parameter calculation of high-voltage DC circuit breaker based on genetic algorithm

    Institute of Scientific and Technical Information of China (English)

    金涛; 蔡超; 王俊; 阮玲

    2013-01-01

    The current waveforms of DC circuit breaker oscillation loop are analyzed by a new on-line parameter estimation method based on genetic algorithm (GA). The method for estimating the parameters of capacitance, inductance and resistance in DC circuit breaker oscillation circuit, can evaluate the performance of DC circuit breaker oscillation loop accurately. According to the on-line monitoring data and off-line measured data of Gezhouba converter station, the veracity and reliability of the new method are validated by comparison with the traditional MAT-LAB curve fitting. The field trials show that GA is better than the traditional method in the aspect of parameter calculation and condition assessment of HVDC circuit breaker.%利用遗传算法对高压直流断路器振荡回路电流波形进行分析,提出对直流断路器振荡回路容抗、感抗和阻尼电阻的值进行在线参数计算的方法,以实现对直流断路器振荡回路性能的正确评估.结合葛上直流输电工程中葛洲坝换流站现场在线监测数据和离线试验数据,通过与MATLAB中利用最小二乘法拟合的结果进行比较,验证了基于遗传算法的高压直流开关参数计算方法的准确性和可靠性.现场试验效果证明遗传算法在高压直流断路器参数计算与状态评估方面优于传统的方法,对实际参数的计算更为准确.

  15. 750 kV断路器现场交流耐压试验系统研究与应用%Site AC Voltage Withstand Test System Study and Application of 750 kV Circuit Breakers

    Institute of Scientific and Technical Information of China (English)

    温定筠; 乔立凤; 江峰; 王成生; 孙亚明; 吕景顺

    2013-01-01

      介绍了750 kV断路器现场交流耐压试验的标准和时序,分析了基于串联谐振原理的试验方法及试验系统中各设备的具体参数。在此基础上配置出成套的750 kV断路器现场交流耐压试验系统,通过实例成功完成了750 kV断路器主回路及断口的交流耐压试验。%  Introduction was made to the standard and time sequence of site AC voltage withstand test of 750 kV circuit breakers. Analysis was made to the test methods based on serial resonance principle and actual parameters of different equipment in test system. On the basis of this, the site AC voltage withstand test system of a set of 750 kV circuit breakers was disposed. The actual example shows that the AC voltage withstand test for the main circuit and breaking outlet of 750 kV circuit breakers could be completed successfully.

  16. Control Strategy and Experimental Study of Hybrid HVDC Circuit Breaker%混合式高压直流断路器的控制策略与实验研究

    Institute of Scientific and Technical Information of China (English)

    杜翼; 江道灼; 陈可; 王玉芬; 尹瑞; 张弛

    2014-01-01

    现有的高压直流断路器能够在几十ms内断开电路,但对于高压直流输电系统,远不能达到要求。基于半导体的高压直流断路器能克服动作速度上的问题,但需要大量电力电子开关器件串并联,有很高的技术难度,同时会产生大量损耗。为了克服上述缺点,采用一种混合式高压直流断路器的拓扑结构。首先介绍了断路器开通和关断的原理,接着提出一种故障预处理的控制策略,在故障发生时提前进行换流,从而缩短故障发生后线路开断的时间;最后利用PSCAD进行建模仿真,制作了单元样机进行降压实验。仿真和实验结果证明:在系统发生短路的情况下,混合式直流断路器能够快速开断短路电流,还可以在直流线路分断后为直流线路及负载中储存的能量提供释放回路。%Existing HVDC circuit breakers are capable of interrupting HVDC currents within several tens of milliseconds, but this is too slow to fulfill the requirements of a reliable HVDC grid.HVDC breakers based on semiconductors can easily overcome the limitations of operating speed,but need large number of the series (parallel ) connection of electronic switching devices;at the same time, it requires high technology and generates a lot of loss. To overcome these shortcomings,a topology of hybrid HVDC circuit breaker was introduced.Firstly,this paper described the principle of hybrid HVDC circuit breaker;then a control strategy of fault pretreatment was also proposed,that was the pre-action of the converter when fault occurred,in order to improve the breaking speed of the hybrid circuit breaker;at last the modeling and simulation were carried out on the hybrid HVDC circuit breaker by PSCAD,and unit prototype was made for the step-down experiments.The simulation and experimental results prove that:when a short circuit occurs,the hybrid HVDC circuit breaker can quickly break the short-circuit current

  17. 继电器、断路器、交流接触器在100 kW发射机中的应用%Relays, Circuit Breakers, AC Contactors used in 100 kW Transmitters

    Institute of Scientific and Technical Information of China (English)

    范学东

    2015-01-01

    DF100 kW transmitter, using a lot of relays, circuit breakers, AC contactor control switch as a transmitter. Detailed summary of all relays, circuit breakers, AC contactors whole transmitter, and various switches for a detailed explanation for reference.%DF100 kW发射机中采用了很多继电器、断路器、交流接触器作为发射机中的控制开关。详细总结了整部发射机的所有继电器、断路器、交流接触器,并对各种开关进行了详细的讲解,以供参考。

  18. Design and Implementation of CAN Bus Interface Used in Intelligent Circuit Breaker%用于智能断路器的CAN总线接口设计与实现

    Institute of Scientific and Technical Information of China (English)

    田莉; 戴瑜兴; 王卫国

    2011-01-01

    Aiming at the trends of remote monitoring of intelligent circuit breaker at present, with combining the monitor computer to realize network control, this paper designed a scheme of communication interface applied in intelligent circuit breakers based on CANbus,and analyzed the transmission conflict between CAN bus and intelligent circuit breaker. Described in detail the hardware and software of CANbus interface, which is based on customer application layer protocol and regards MCU MC9S08DZ32 with embedded CAN controller as the core, formed a complete communication and one master multi-network program. The practical run results show that this scheme provide a solution for the remote monitoring of intelligent circuit breaker, make it stability, low cost, have broad application prospects.%针对目前智能断路器远程监控的发展趋势,在结合上位监控计算机实现网络控制的基础上,设计了一种基于CAN总线的智能断路器通信接口的设计方案,并对CAN接口与智能断路器的传输冲突进行了分析;详细设计了基于自定义应用层协议、以内嵌CAN控制器的MC9508DZ32为核心的CAN总线接口的软硬件设计与实现,形成一个完整的一主多从通信方案;实际运行结果表明,该通信方案为实现智能断路器的远程监控提供了一个解决方案,稳定性好,成本较低,具有广阔的应用前景.

  19. TAN/LOFT 13. 8 KV, 2. 4 KV, and 480 V relay and circuit breaker coordination study

    Energy Technology Data Exchange (ETDEWEB)

    Burnett, J.E.

    1977-10-28

    Present overcurrent relay settings are presented and evaluated for adequacy in terms of the updated short circuit analysis. Recommendations are made for new relay and trip device settings to improve coordination. Switchgear ratings are examined against available short circuit currents, and recommendations are made where applicable. Vital MCC-A and B are examined in detail to provide maximum continuity of service for every fault contingency. A recommendation is made to improve the reliability of these buses.

  20. Path Tracking Control of Vacuum Circuit Breaker%真空断路器循迹控制

    Institute of Scientific and Technical Information of China (English)

    秦涛涛; 董恩源; 陈宇硕; 段雄英; 邹积岩

    2014-01-01

    采用带自调整函数的模糊算法,能够使断路器永磁机构按给定曲线动作,保证断路器的合闸时间稳定,从而提高选相操作的精度。通过该算法可实时纠正断路器永磁机构的运动位移偏差,在电容电压、环境温度等外界因素发生变化时,使机构仍按给定曲线动作。通过开关特性测试仪和DSP2812硬件控制系统,得到标准位移曲线及控制算法中的基本参量值,并在 Matlab 中建立了考虑续流过程的真空断路器闭环控制系统,给出了电容电压变化的仿真结果,验证了上述控制方法的可行性。此外,针对单相配永磁机构真空断路器,进行大量的合闸实验。实验结果表明:在上述外界因素变化时,该控制方法能将断路器合闸时间稳定在±0.5 ms之内。%A fuzzy algorithm with self-turning function was proposed in this paper to make Permanent Magnetic Actuator (PMA) move along with the given displacement curve. Then the closing time of PMA is stable and the precision of phase-selection operation is improved. The deviation of displacement, caused by the variation of capacitor voltage and ambient temperature, can be corrected by the algorithm in real time. So PMA can still move along with the given displacement curve. The standard displacement curve and the basic parameters were obtained by the high-voltage switch testing equipment and hardware system DSP2812 respectively. Meanwhile, a closed-loop system, considering free-wheeling process of coil, was established in the software Matlab to verify the feasibility of the algorithm when the voltage of capacitor varied. In addition, a large number of tracing experiments have been done on the breakers and the results proved that closing time of breaker can be stabilized within±0.5ms under the condition of changing capacitor voltage and ambient temperature.

  1. Advantages of the synthetic technique for the conduction of short circuit tests to breakers; Ventajas de la tecnica sintetica para realizar pruebas de corto circuito a interruptores

    Energy Technology Data Exchange (ETDEWEB)

    Sibilski, Henry [Instituto Electrotecnico de Varsovia, Varsovia (Poland); Ochoa Vivanco, Ruben [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1986-12-31

    In this article the operational principle of the synthetic test is described; specifically of the current injection circuit in parallel. Its utilization in the research and development of new breaker models and its wide possibilities regarding its testing characteristics is outlined. Likewise the different tests that can be performed by means of the synthetic technique are described. Finally the importance of the synthetic tests is outlined for the development of own technology in the area of interruption equipment and emphasis is made that in industrialized countries this technique is of common practice. [Espanol] En este articulo se describe el principio de operacion de la prueba sintetica; especificamente del circuito de inyeccion de corriente en paralelo. Se destaca su utilizacion en la investigacion y desarrollo de nuevos modelos de interruptores y sus amplias posibilidades en cuanto a caracteristicas de prueba. Asimismo, se describen las diferentes pruebas que pueden realizarse mediante la tecnica sintetica. Por ultimo, se destaca la importancia de las pruebas sinteticas para el desarrollo de tecnologia propia en el area de equipos de interrupcion, y se hace notar que en paises desarrollados, esta tecnica es practica comun.

  2. Mechanical Fault Diagnosis of High Voltage Circuit Breakers Based on Wavelet Time-Frequency Entropy and One-Class Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Nantian Huang

    2015-12-01

    Full Text Available Mechanical faults of high voltage circuit breakers (HVCBs are one of the most important factors that affect the reliability of power system operation. Because of the limitation of a lack of samples of each fault type; some fault conditions can be recognized as a normal condition. The fault diagnosis results of HVCBs seriously affect the operation reliability of the entire power system. In order to improve the fault diagnosis accuracy of HVCBs; a method for mechanical fault diagnosis of HVCBs based on wavelet time-frequency entropy (WTFE and one-class support vector machine (OCSVM is proposed. In this method; the S-transform (ST is proposed to analyze the energy time-frequency distribution of HVCBs’ vibration signals. Then; WTFE is selected as the feature vector that reflects the information characteristics of vibration signals in the time and frequency domains. OCSVM is used for judging whether a mechanical fault of HVCBs has occurred or not. In order to improve the fault detection accuracy; a particle swarm optimization (PSO algorithm is employed to optimize the parameters of OCSVM; including the window width of the kernel function and error limit. If the mechanical fault is confirmed; a support vector machine (SVM-based classifier will be used to recognize the fault type. The experiments carried on a real SF6 HVCB demonstrated the improved effectiveness of the new approach.

  3. Study on Reliability Test System for Miniature Circuit Breaker Based on Virtual Instrument Technology%基于虚拟仪器技术的小型断路器可靠性试验系统的研究

    Institute of Scientific and Technical Information of China (English)

    曾学礼; 李笑来; 鲁修军; 张利; 李文华

    2012-01-01

      Introduction was made to the main functions and working principle of a reliability test system for the miniature circuit breaker based on virtual instrument technology. Description was made to the software design flow and some sub functional modules of the test system. The reliability test system for the miniature circuit breaker designed with LabVIEW can realize automatic control for test, carrying out data collection and treatment in real time, parameters amending and correcting, storing and inquiring of related test data etc functions. The operation reliability test and impulse reliability test were carried out for the miniature circuit breaker ac-cording to GB/Z 22203—2008 “Reliability test method for over current protection circuit breaker for home and similar place use”. Practice shows that the miniature circuit breaker reliability test system using virtual instrument technology is stable in performance, simple and convenient in operation, rich in functions with very good prospect in application popularization.%  介绍了基于虚拟仪器技术开发的小型断路器可靠性试验系统的主要功能、工作原理,阐述了试验系统的软件设计流程及部分子功能模块。利用 LabVIEW 软件设计的小型断路器可靠性试验系统可以实现试验的自动控制,完成对数据的实时采集处理、参数修改与校正、相关试验数据的保存与查询等功能。可依照 GB/Z 22203—2008《家用及类似场所用过电流保护断路器的可靠性试验方法》对小型断路器进行操作可靠性试验和瞬动可靠性试验。实践证明,采用虚拟仪器技术开发的小型断路器可靠性试验系统性能稳定、操作简便、功能丰富,有很好的推广应用前景

  4. 真空断路器新型电机操动机构的多体动力学仿真%Multi-Body Dynamics Simulation and Analysis on Novel Motor-Operating Mechanism for Vacuum Circuit Breakers

    Institute of Scientific and Technical Information of China (English)

    林莘; 宋立峰; 李永祥; 徐建源

    2012-01-01

    To improve the reliability of circuit breakers, a new motor-operating mechanism, which possesses such advantages as simple structure, small size, fast response and controllable moving process, is developed. The focal point of the research is concentrated to the switching on/off characteristics of vacuum circuit breaker with motor-operating mechanism. Taking a 40.5kV vacuum circuit breaker with motor operating mechanism as research object and using automatic dynamic analysis of mechanical systems (ADAMS), a virtral prototype model of vacuum circuit breaker with a new type of motor-operating mechanism is built to simulate the switching on/off processes of the circuit breaker. From simulation results corresponding relation between the rotated angle of the motor and the stroke of the contact of circuit breaker as well as the characteristics of contact stroke and speed vs time during the switching on/off process are obtained. Meanwhile, the experiments of switching on/off of the vacuum circuit breaker are made and the corresponding moving characteristics are measured by the torque sensor installed on the rotating shaft and the displacement sensor installed on insulating tension pole. Contrastive analysis on results from experiments and simulation shows that the output characteristics of the simulation model can well conform to experiment results, thus it also states clearly that the virtual prototype model is effective.%为提高断路器的可靠性,研究了一种新型的电机机构,该电机机构具有结构简单、体积小、响应快且运动过程可控等优点,研究重点为在电机机构操作下真空断路器的分广合闸机械特性。结合40.5kV配电机机构的真空断路器,采用多体动力学仿真软件(automatic dynamic analysis of mechanicai systems,ADAMS)建立真空断路器新型电机机构的虚拟样机模型,对断路器的分/合闸过程进行仿真分析。由动态仿真得到电机转角与动触头

  5. Measurement of arc resistance and conductance during interruption of high frequency current on SF sub 6 circuit breaker. SF sub 6 gas shadanki no koshuha denryu shadanji no arc teiko, arc conductance no sokutei hoho

    Energy Technology Data Exchange (ETDEWEB)

    Okabe, S.; Yorozuya, T.; Zaima, E. (The Tokyo Electric Power Co. Inc., Tokyo (Japan)); Nishiwaki, S.; Ishikawa, M.; Nakamoto, T.; Yokota, T. (Toshiba Corp., Tokyo (Japan))

    1991-07-15

    A high-frequency surge may occur when a power ciruit breaker develops re-arcing or reignition at its interruption, but measuring the arc voltage is not easy as it is much lower than the circuit voltage, making diffecult to precisely analyze the surge phenomenon. Therefore, this paper describes building a test circuit simulating re-arcing in a 300 kV, SF{sub 6} gas buffer type model breaker, and measuring the high-frequency current and its arc voltage using the method described as follows. For instance, to minimize measurement errors caused from stray inductance voltage drop, an insulation spacer was installed in the vicinity of the breaker contact as a capacitance for the voltage-divider. The partial potential factor of the voltage-divider was set for measuring arc voltage of several kilovolts, and clippers were installed for large voltage signals. As a result of correcting various errors and preventing noise in optical transmission, the arc resistance and conductance were derived. 10 refs., 14 figs., 1 tab.

  6. 220kV双母分段带旁路接线的断路器失灵保护分析%Failure Protection Analysis of Circuit Breaker of 220kV Sectionalized Double-bus Wiring Mode with Bypass Bus

    Institute of Scientific and Technical Information of China (English)

    黄锷; 邓建峰; 杨柳

    2012-01-01

    为深入了解断路器失灵保护、提高变电站运行可靠性,针对大型变电站中接线方式最为复杂的双母分段带旁路主接线,按设备种类分析了每种设备断路器失灵保护的特点、启动原理和联跳主变三侧断路器原理、回路设计及应用情况,并提供了旁路带线路及主变断路器时应在失灵保护上特别关注的经验.%In order,to understand the circuit breaker failure protection deeply and improve the reliability of substations, aiming at the complex sectionalized double-bus wiring mode with bypass bus, the failure protection characteristics and start-up principle of circuit breaker are analyzed based on the equipment types. The united jumping principle of the three side circuit breakers of main transformer, circuit design and application are also discussed. Some useful experiences of circuit breaker failure protection are supplied for bypass bus driving line and transformer circuit breaker.

  7. 14 CFR 23.1357 - Circuit protective devices.

    Science.gov (United States)

    2010-01-01

    ... circuit breakers, must be installed in all electrical circuits other than— (1) Main circuits of starter... circuit breaker or replace a fuse is essential to safety in flight, that circuit breaker or fuse must be... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Circuit protective devices. 23.1357...

  8. 大容量SF6发电机断路器关键技术的探讨%Discussion on the Key Technologies of Large Capacity SF6 Generator Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    徐齐巍

    2015-01-01

    针对我国电力事业需求及国内发电机断路器的技术水平,阐述国内发电机断路器的发展趋势和迫切目标,提出推进国内发电机断路器发展进程的关键点;通过引入国际先进理念,探讨大容量SF6发电机断路器的关键技术,在结构型式、灭弧原理、特殊性能指标、冷却方式、操动机构方面进行深入研究,并针对该关键技术的难点问题提出解决思路,为研发满足60万kW以上至100万kW机组要求的额定短路电流160 kA以上的大容量、高参数、运行可靠的SF6发电机断路器提供理论依据。%Based on the demand of electric undertaking in china and the technological level of national generator circuit breaker , the development trend and the exigent goal are expounded, and the cores of furthering development course for national generator circuit breaker is put forward. Through importing international advanced ideas, the key technologies of large capacity SF6 generator circuit breaker are discussed. An embedded research in respects of construction form, arc interruption principle, special performance target, cooling type and operating mechanism is made, solving ideas are provided in allusion to the difficulties in key technologies, and theoretical basis is supplied for researching large capacity SF6 generator circuit breaker with rated short-circuit current being upwards of 160 kA, and with high parameter and running reliability in order to settle for the demand of the generating units with a capacity of 600 MW up to 1 000 MW.

  9. "Hyperglutamatergic cortico-striato-thalamo-cortical circuit" breaker drugs alleviate tics in a transgenic circuit model of Tourette׳s syndrome.

    Science.gov (United States)

    Nordstrom, Eric J; Bittner, Katie C; McGrath, Michael J; Parks, Clinton R; Burton, Frank H

    2015-12-10

    The brain circuits underlying tics in Tourette׳s syndrome (TS) are unknown but thought to involve cortico/amygdalo-striato-thalamo-cortical (CSTC) loop hyperactivity. We previously engineered a transgenic mouse "circuit model" of TS by expressing an artificial neuropotentiating transgene (encoding the cAMP-elevating, intracellular A1 subunit of cholera toxin) within a small population of dopamine D1 receptor-expressing somatosensory cortical and limbic neurons that hyperactivate cortico/amygdalostriatal glutamatergic output circuits thought to be hyperactive in TS and comorbid obsessive-compulsive (OC) disorders. As in TS, these D1CT-7 ("Ticcy") transgenic mice׳s tics were alleviated by the TS drugs clonidine and dopamine D2 receptor antagonists; and their chronic glutamate-excited striatal motor output was unbalanced toward hyperactivity of the motoric direct pathway and inactivity of the cataleptic indirect pathway. Here we have examined whether these mice׳s tics are countered by drugs that "break" sequential elements of their hyperactive cortical/amygdalar glutamatergic and efferent striatal circuit: anti-serotonoceptive and anti-noradrenoceptive corticostriatal glutamate output blockers (the serotonin 5-HT2a,c receptor antagonist ritanserin and the NE alpha-1 receptor antagonist prazosin); agmatinergic striatothalamic GABA output blockers (the presynaptic agmatine/imidazoline I1 receptor agonist moxonidine); and nigrostriatal dopamine output blockers (the presynaptic D2 receptor agonist bromocriptine). Each drug class alleviates tics in the Ticcy mice, suggesting a hyperglutamatergic CSTC "tic circuit" could exist in TS wherein cortical/amygdalar pyramidal projection neurons׳ glutamatergic overexcitation of both striatal output neurons and nigrostriatal dopaminergic modulatory neurons unbalances their circuit integration to excite striatothalamic output and create tics, and illuminating new TS drug strategies.

  10. Direct current hybrid breakers: A design and its realization

    Science.gov (United States)

    Atmadji, Ali Mahfudz Surya

    2000-12-01

    The use of semiconductors for electric power circuit breakers instead of conventional breakers remains a utopia when designing fault current interrupters for high power networks. The major problems concerning power semiconductor circuit breakers are the excessive heat losses and their sensitivity to transients. However, conventional breakers are capable of dealing with such matters. A combination of the two methods, or so-called `hybrid breakers', would appear to be a solution; however, hybrid breakers use separate parallel branches for conducting the main current and interrupting the short-circuit current. Such breakers are intended for protecting direct current (DC) traction systems. In this thesis hybrid switching techniques for current limitation and purely solidstate current interruption are investigated for DC breakers. This work analyzes the transient behavior of hybrid breakers and compares their operations with conventional breakers and similar solid-state devices in DC systems. Therefore a hybrid breaker was constructed and tested in a specially designed high power test circuit. A vacuum breaker was chosen as the main breaker in the main conducting path; then a commutation path was connected across the vacuum breaker where it provided current limitation and interruption. The commutation path operated only during any current interruption and the process required additional circuits. These included a certain energy storage, overvoltage suppressor and commutation switch. So that when discharging this energy, a controlled counter-current injection could be produced. That counter-current opposed the main current in the breaker by superposition in order to create a forced current-zero. One-stage and two-stage commutation circuits have been treated extensively. This study project contains both theoretical and experimental investigations. A direct current shortcircuit source was constructed capable of delivering power equivalent to a fault. It supplied a direct

  11. Design of Mechanical Characteristics Test Instrument for Vacuum Circuit Breaker Base on Linux%基于Linux的真空断路器机械特性测试仪的设计

    Institute of Scientific and Technical Information of China (English)

    胡敏

    2011-01-01

    真空断路器的可靠性,主要依赖于其机械特性的可靠性,而这需要有相应的测试设备来对其状态进行检测,便于工作人员对其进行维护.真空断路器机械特性测试仪是以嵌入式Linux为平台构建的嵌入式操作系统,运用Qt/E编写了界面美观、人机交互性能良好的操作控制图形用户界面程序,运用MySQL数据库编写相应的程序模块实现检测结果的存储、查询和传输,达到高精度、高性能、操作简便实现真空断路器机械特性参数测试的目的.%The reliability of vacuum circuit breaker mainly depends on Its mechanical characteristic, which needs relevant test equipment to give a test so as to maintain the vacuum circuit breaker. Embedded operating system is developed based on the embedded Linux. In this system, Qt/E is used to edit graphical user interface programs. Based on MySQL database, we edit relevant program module to store,retrieve and transfer testing results,in order to attain the goal of testing mechanical characteristic parameter of vacuum circuit breaker with high precision, high performance and easy operation.

  12. Study on Current Tests of 145 kV Circuit Breakers for Capacitor Bank Current Switching%145kV断路器开合电容器组电流试验研究

    Institute of Scientific and Technical Information of China (English)

    黄实; 崔博源; 姚斯立; 李志兵; 刘浩军

    2012-01-01

    The standard selection, test method, parameters of test circuit, and test requirement for the current tests of 145 kV circuit breakers for capacitor bank switching are researched, and the test situation is introduced. The performance of 145 kV circuit breakers for capacitor bank switching is examined by using the conclusion of this research to ensure their security and reliability.%笔者研究了145 kV断路器开合电容器组电流试验的标准选用、试验方法、试验回路参数、试验要求等,并介绍了试验情况.研究成果的应用使得145 kV投切电容器组断路器的开合电容器组性能得到了型式试验考核,为工程的安全可靠运行提供了保障.

  13. 基于IGBT串联技术的混合式高压直流断路器方案%A Hybrid High Voltage DC Circuit Breaker Design Plan With Series-Connected IGBTs

    Institute of Scientific and Technical Information of China (English)

    药韬; 温家良; 李金元; 陈中圆

    2015-01-01

    Vigorously developing renewable energy will be an inevitable choice to solve the unbalanced distribution of energy resources, ease the tension between electricity supply and demand, and achieve sustainable economic development in China. To integrate conventional DC transmission technology and flexible DC transmission technology, establishing HVDC grid would be an effective means to solve the problem of large scale grid-connected of renewable energy. In this paper the history of HVDC circuit breaker is reviewed, the latest research results are introduced, the current challenges for HVDC circuit breaker are illustrated. Also the typical topological structure, working principle, advantages and shortcomings of different types of HVDC circuit breaker are analyzed and compared. Based on this, a new hybrid HVDC circuit breaker design with series-connected insulated gate bipolar transistors (IGBTs) is presented, and the topology characteristics and its working principles are introduced in details. Zhoushan five-terminal DC transmission system is modeled and simulated in the PSCAD/EMTDC software to verify its feasibility.%大力发展可再生能源将是解决我国能源资源分布不平衡,电力供需紧张,实现经济可持续发展的必然选择.综合常规直流输电技术和柔性直流输电技术,建立高压直流电网将是解决大规模可再生能源并网问题的有效手段.回顾高压直流断路器的发展历程,介绍当前最新的研究成果,阐明现阶段高压直流断路器将要面临的挑战,分析比较不同类型高压直流断路器的典型拓扑结构、工作原理和优缺点.在此基础上提出一种基于绝缘栅双极型晶体管(insulated gate bipolar transistor,IGBT)串联技术的混合式高压直流断路器方案,详细介绍其拓扑结构、特点和工作原理,基于舟山5端直流工程在PSCAD/EMTDC软件中搭建仿真模型验证了其可行性.

  14. 智能4极断路器非正常跳闸问题及其解决%Improper Trip of Intelligent 4-Pole Circuit Breaker and Its Resolution

    Institute of Scientific and Technical Information of China (English)

    黄友民; 章永孚

    2001-01-01

    The cause of the improper trip of 4-pole circuit breaker was analyzed. A subsidiary power voltage is applied to solve the problem. It is proved in practice that this measure is feasible and effective.%分析了4极断路器非正常跳闸的原因,提出采用施加外接辅助电源电压的解决措施。经实际应用证明该措施行之有效。

  15. 220 kV变电站GIS断路器短路典型事故分析%Analysis on Typical GIS Breaker Short-circuit Fault in 220 kV Substation

    Institute of Scientific and Technical Information of China (English)

    李晓刚

    2014-01-01

    介绍了某220 kV变电站气体绝缘金属封闭开关设备(gas insulated metal enclose switchgear,GIS)断路器短路事故经过。通过对220 kVGIS短路事故后的故障录波、气体成分、断路器解体及出厂原始数据的综合分析,认为在出厂时的雷电冲击试验中的击穿、放电造成的断路器极间绝缘筒的缺陷是事故发生的主要原因。并通过事故过程的还原从另一角度验证了事故原因分析的正确性,并提出了相应的建议,同时为类似 GIS 故障的处理分析提供借鉴与参考。%This paper introduces one GIS breaker short-circuit accident in some 220 kV substation.By comprehensively analy-zing fault recording,gas components,breaker disintegration and factory original data after the short-circuit fault,the main reason for the accident was considered to be defect of breaker interelectrode insulating cylinder caused by breakdown and discharge in factory lightning impulse test.Meanwhile,by review on the accident,correctness of accident reason analysis was verified from another angle and relevant suggestions were proposed for providing references on similar GIS fault handling a-nalysis.

  16. Detection Method of High Voltage Circuit Breaker and Its Application Based on Ultrasonic Sensor%基于超声波传感器的高压断路器检测方法及应用

    Institute of Scientific and Technical Information of China (English)

    程旭东; 王兰芳

    2011-01-01

    In order to improve the efficiency and precision of velocity detection of High voltage circuit breaker (HVCB), a detection method based on ultrasonic sensor is proposed. The TR40 series of ultrasonic transducer is adopted to generate ultrasonic signals. The emission sensor is fixed on the breaker's closing/opening connection rod while receiving sensor installed in the universal triangular bracket. By measuring the frequency difference between emission signals and receiving signals, instantaneous velocity of the current circuit breaker operation can be calculated. Furthermore, a mechanical characteristic detection instrument for HVCB is developed. Field test results show that the ultrasonic sensor is convenient to be installed and the results has high accuracy and small uncertainty, which satisfies the field test requirements for velocity detection of HVCB.%为提高高压断路器速度检测效率与精度,提出了一种基于超声波传感器的高压断路器速度检测方法,利用TR40系列超声波换能器产生超声波信号,将发射传感器固定于断路器合/分连接杆上,接收传感器安装在万能三角支架上,通过统计接收和发送信号的频率差,计算当前断路器运行的瞬时速度,并在此基础上开发了断路器机械特性测试仪.现场试验结果表明,超声波传感器安装方便、测试数据精度较高、不确定度小,能满足高压断路器现场速度检测的需求.

  17. 一种电容器断路器与三工位隔离开关装置的研发%Development of a Capacitor Circuit Breaker and Three Working Position Disconnector

    Institute of Scientific and Technical Information of China (English)

    关士深; 李春东; 郭中杰

    2014-01-01

    一种电容器断路器与三工位隔离开关装置,断路器可以单相操作,满足单相电容器组投入时与该相电压过零点同步;切除电容器组时与该相电流过零点同步,消除电容器组投切时产生的过电压,降低涌流,提高电容器的使用寿命;三工位隔离开关设计成导柱移动式封闭结构,动作准确,绝缘可靠性高。%In this paper,a kind of capacitor circuit breaker and disconnector are introduced. The cir-cuit breaker can be of single phase operation,meet voltage zero synchronize with the single phase in case of single phase capacitor bank switching on,current zero synchronize with the phase in case of switching off,eliminate overvoltage generated during switching capacitor bank, reduce surge current and improve the operation life of the capacitor. The three working position disconnector is designed into mobile enclosed type with correct operation and high insulation reliability.

  18. The Outer Insulation Characteristics of ac 500 kV Filter Circuit Breaker at High Altitude%高海拔500kV交流滤波断路器外绝缘特性

    Institute of Scientific and Technical Information of China (English)

    吕刚; 陆岩; 田应富

    2011-01-01

    地处高海拔地区的500 kV贵广Ⅰ回直流输电系统高坡换流站中多次出现交流滤波断路器外绝缘闪络事故.分析了断路器外绝缘闪络的机理,通过人工污秽试验确定了闪络电压变化情况,确认故障是高海拔地区恶劣天气条件下污秽断路器灭弧室外绝缘降低所致,基于试验结果提出了防止断路器污秽闪络的措施.%Flash faults of ac filters at Gaopo substation of Guizhou-Guangdong 500 kV HVDC transmission system have heppened many times. The mechanism of the flash is analyzed in this paper, and through artificial contamination tests for displaying the voltage change of flash the cause of these flash faults is discovered as follows: The outer insulation of filthy circuit breaker's arc-chute lowered by the inclement weather condition in the high altitude area. Furthermore, countermeasures against the flash of filthy circuit breaker are proposed based on the experimental results.

  19. Design of Test Circuits of DC Circuit Breaker for High Voltage Direct Current (HVDC) Distribution System-Ⅱ%高压直流输电用直流转换开关转换电流试验回路的分析与设计(2)

    Institute of Scientific and Technical Information of China (English)

    那虎; 丁正平; 孙晋峰; 杨俊清; 刘龙开; 袁方; 洪深

    2013-01-01

    For testing the high voltage direct current (HVDC) circuit breakers of HVDC distribution system in laboratory, the working conditions and characteristics of HVDC distribution system are analyzed, and two test circuits for the HVDC circuit breakers are designed according to the grid parameters and working condition requirements, as well as PSCAD simulations. The design of one of the test circuits, named direct test circuit, is described in detail and calculated.%针对超高压直流输变电系统用的直流开关转换设备的检验检测如何在试验室实施,笔者通过对直流输电系统的运行工况及特性进行研究,依据电网参数及工况的要求定性试验方法或方式.通过对转换电流开断能力试验的相关分析及PSCAD仿真试验模拟,设计了两种试验回路以满足试验参数的要求,文中介绍其中之一合成试验回路的设计及分析,并进行计算,对其实施进行了必要的阐述和探讨.

  20. 高压直流输电用直流转换开关转换电流试验回路的分析与设计(1)%Design of Test Circuits of DC Circuit Breaker for High Voltage Direct Current(HVDC) Distribution System-Ⅰ

    Institute of Scientific and Technical Information of China (English)

    那虎; 丁正平; 孙晋峰; 杨俊清; 刘龙开; 袁方; 洪深

    2012-01-01

    For testing the high voltage direct current (HVDC) circuit breakers of HVDC distribution system in laboratory, the working conditions and characteristics of HVDC distribution system are analyzed, and two test circuits for the HVDC circuit breakers are designed according to the grid parameters and working condition requirements, as well as PSCAD simulations. The design of one of the test circuits, named direct test circuit, is described in detail and calculated.%针对超高压直流输变电系统用的直流开关转换设备的检验检测如何在试验室实施,笔者通过对直流输电系统的运行工况及特性进行研究,依据电网参数及工况的要求定性试验方法或方式.通过对转换电流开断能力试验的相关分析及PSCAD仿真试验模拟,设计了两种试验回路以满足试验参数的要求,文中介绍其中之一合成试验回路的设计及分析,并进行计算,对其实施进行了必要的阐述和探讨.

  1. 14 CFR 29.1357 - Circuit protective devices.

    Science.gov (United States)

    2010-01-01

    ... the position of the operating control. (d) If the ability to reset a circuit breaker or replace a fuse is essential to safety in flight, that circuit breaker or fuse must be located and identified so that... circuit protection. (g) Automatic reset circuit breakers may be used as integral protectors for...

  2. Fault Analysis and Prevention of BLK222 Spring Mechanism in LTB245E1 Circuit Breaker%LTB245E1型断路器BLK222型弹簧机构的故障分析和预防

    Institute of Scientific and Technical Information of China (English)

    孙兵

    2013-01-01

    LTB245E1型断路器是目前应用于电力企业的主流开关设备,为北京ABB公司生产的220kV SF6断路器,该型断路器配BLK222型弹簧操动机构.通过对该型断路器弹簧机构故障原因的分析,找出此类型机构存在的诸多问题,并就如何加强SF6断路器的检修维护管理提出了一些措施和建议,以预防电气故障的发生.%LTB245E1 circuit breaker is a widely used switch equipment in electric power enterprise currently. It's the 220 kv SF6 circuit breaker produced by Beijing ABB company. This type of circuit breaker is equipped with BLK222 spring operating mechanism. Based on the fault analysis of spring mechanism, we found out many problems in it and then put forward some measures and suggestions to strengthen the maintenance management of SF6 circuit breaker, which is supposed to prevent the occurrence of electrical fault.

  3. 真空断路器电磨损监测与诊断方法综述%Review of Monitoring and Diagnosis Methods for Vacuum Circuit Breaker Electrical Wear

    Institute of Scientific and Technical Information of China (English)

    范兴明; 贺家敏; 潘永成; 刘旭东; 黄知超; 张鑫; 李震; 刘华东

    2011-01-01

    随着基于智能电网、数字化变电站、非常规互感器技术及IEC 61850标准和基于可靠性的状态检修体制的发展,高压开关设备的智能化逐渐引起电器生产和使用人员的重视.文中描述了影响真空断路器电寿命的判据,分析了真空断路器触头电寿命及其在工程应用中的可行折算式,总结了国内外监测开断电流起孤时刻的方法.以分析为基础并概述了各种不同折算式的适用性及各种监测方法的特点,着重强调了各种方法的工程实用性和起弧时刻监测的重要性,并在此基础上讨论了现有检修和检测手段的缺陷,展望了真空断路器电寿命监测技术发展的方向.%Accompany with the application of intelligent power grid, digitized substation,unconventional transformer technology, IEC 61850 standards and the development of condition-based maintenance system(CBMS) that attention is highly paid to the HV intelligent switchgear by the electrical device producer and the user.The electrical-endurance quality of vacuum circuit-breaker is described, and the vacuum circuit breaker contactor wear is analyzed. Then the application of feasible calculation formula in engineering is discussed. Methods of monitoring arcing duration at home and abroad are summarized, and the applicability of applications of different calculation converted formulas are presented and the characteristics of various monitoring methods are investigated, which based on a series of analysis. The engineering practicability and the arcs moment monitoring are mainly emphasized. In the end the defects of maintenance and detection are discussed and the technology development direction of vacuum circuit breaker's electrical endurance is prospected, which based upon what mentioned above.

  4. Thyristor Based Hybrid Arc-less High Voltage Direct Current Circuit Breaker%基于晶闸管的混合型无弧高压直流断路器

    Institute of Scientific and Technical Information of China (English)

    周万迪; 魏晓光; 高冲; 罗湘; 曹均正

    2014-01-01

    Increasing HVDC transmission project gradually attracts the researcher’s attention to the high voltage DC circuit breaker (DCCB), which is the interrupt equipment in DC line. The DCCB could promote the realization of multi-terminal direct current (MTDC) and DC grid, and advance the development of renewable energy such as offshore wind power. This paper firstly compared the various existing circuit breaker. A thyristor based on hybrid arc-less high voltage DCCB topology was proposed. According to the equivalent mathematical models established in the paper, the critical instants and electrical parameters for different operating stages of the DCCB were derived. Operating performance of the DCCB for Zhou Shan 5 terminals 200 kV DC system was analyzed using PSCAD/EMTDC simulations, which was compared from technology and economic aspects, and the correctness of the theoretical analysis and the feasibility of the circuit breaker were also proved.%伴随着高压直流输电工程日益增长,直流断路器作为直流线路中分断装置,也逐步受到了研究人员的关注,其能够促进多端直流及直流电网实现,推动可再生能源尤其是海上风电的开发。首先简要回顾了高压直流断路器研究状况,对现有方案进行了比较分析。随后提出了一种基于晶闸管的混合型无弧高压直流断路器,通过等效数学模型对工作阶段的电气参数和临界时刻进行了计算。最后以舟山5端直流系统电压200 kV为参照,利用PSCAD/EMTDC开展了断路器仿真研究,验证了理论分析的正确性以及所提断路器的可行性,并从技术和经济角度开展了性能分析。

  5. Review on Out-Of-Phase Making and Breaking Test Method of High-Voltage Circuit Breaker%高压断路器失步开合试验方法的评述

    Institute of Scientific and Technical Information of China (English)

    吴盛刚; 张建新; 赵建沛; 王鹏飞; 周跃刚

    2013-01-01

    Description was made to the multiple test circuits and the test conditions of high-voltage circuit breakers in carrying out out-of-phase making and breaking test and comparison was made to their advantages and disadvantages. According to the actual test conditions in test station, this paper selected transformer double-circuit which is convenient to carry out and parallel voltage injec-tion circuit and calculated parameters of 126 kV level test loop. Simulation was carried out for the relevant transient recovery voltage waveforms. The result is in conformity with the expected requirements, so it can be implemented.%阐述了高压断路器进行失步开合试验的多种试验线路及其试验条件,并比较了各自的优缺点。根据试验站的具体设备条件,选取了便于实施的变压器双联电路和并联电压引入回路,并计算了126 kV级试验回路的参数,对相应的瞬态恢复电压TRV波形进行了仿真,其结果符合预期要求,故可以实施。

  6. 真空断路器弹簧操动机构的稳健优化设计%Design for Spring Actuator of Vacuum Circuit Breaker Based on Robust Optimization

    Institute of Scientific and Technical Information of China (English)

    陈刚; 孙波; 刘晓明; 王尔智

    2013-01-01

    For the spring actuator of 12kV,12. 5kA vacuum circuit breaker,a mathematical model calculating the breaking and closing velocity based on mechanism analysis was given. The design for spring actuator of vacuum circuit breaker based on robust optimization was presented. The lengths of the connecting rods and the stiffness coefficient of breaking and closing spring of the spring actuator were chosen as the optimization variables. The effect of the factors, as processing errors,assembly error, ageing and fatigue,was considered as the tolerance of design variables. The functions,which were used to minimize the error of the breaking and closing velocity of vacuum circuit breaker and to minimize the maximal variation of these velocity when the design variables varied within the acceptable tolerances, were chosen as the objective function. So a robust optimization mathematical model with multi — target and two—level optimization for the spring actuator was given. A series of optimization strategy were presented,and the algorithm was tested by using a classical standard test function. The performance of 12kV,12. 5kA vacuum circuit breaker is improved by robust optimization. The numerical example shows the effectiveness of the method.%在分析10kV/12.5kA真空断路器弹簧操动机构基础上,建立了分合闸速度的计算模型.在此断路器的数学模型基础上,将稳健设计思想和优化设计思想相结合,将弹簧操动机构中各杆件的长度和分合闸弹簧的刚度系数作为设计变量,将加工误差、装配误差、老化、疲劳等因素引起的影响考虑在设计变量的容差之中,以真空断路器的分合闸速度的方差最小化,且当设计变量在其容差内变化时分合闸速度的最大波动量最小化为优化目标,建立了具有多目标、两级优化的弹簧操动机构稳健优化设计数学模型.提出了一系列求解该数学模型的优化策略,运用经典的测试函数验

  7. 探讨高压断路器机械故障及改进方法%Discussion on Mechanical Failure of High Voltage Circuit Breaker and Its Improvement

    Institute of Scientific and Technical Information of China (English)

    杨志钧

    2016-01-01

    高压断路器是电力系统的重要执行元件,能够灵巧地实现系统运行方式的变化和倒闸操作的要求,是电力系统及设备能够安全稳定运行的重要保证。随着社会经济的快速发展,对供电的安全性、质量性、可靠性和经济性提出了更高的要求。本文从实际出发,系统的对高压断路器在运行时的常见的故障问题进行分析,提出合理的改进措施,并结合案例论述改进措施的有效性。希望本文对从事断路器维护及修理的工作人员有一定的指导作用。%High voltage circuit breaker is an important executive component of the power system. It can deftly achieve the change of system operation mode and the request of switching operation. It is an important guarantee for the safe and stable operation of power system and equipment. With the rapid development of social economy, it is put forward higher requirements for the security, quality, reliability and economy of power supply. This article from the reality, systematically analyzed the common faults in the operation of high voltage circuit breakers, put forward reasonable improvement measures, and combining with the case discussed the effectiveness of improvement measures.

  8. Rectifier cabinet static breaker

    Science.gov (United States)

    Costantino, Jr, Roger A.; Gliebe, Ronald J.

    1992-09-01

    A rectifier cabinet static breaker replaces a blocking diode pair with an SCR and the installation of a power transistor in parallel with the latch contactor to commutate the SCR to the off state. The SCR serves as a static breaker with fast turnoff capability providing an alternative way of achieving reactor scram in addition to performing the function of the replaced blocking diodes. The control circuitry for the rectifier cabinet static breaker includes on-line test capability and an LED indicator light to denote successful test completion. Current limit circuitry provides high-speed protection in the event of overload.

  9. 14 CFR 25.1357 - Circuit protective devices.

    Science.gov (United States)

    2010-01-01

    ...) If the ability to reset a circuit breaker or replace a fuse is essential to safety in flight, that circuit breaker or fuse must be located and identified so that it can be readily reset or replaced in... must be designed so that circuit breakers are not the primary means to remove or reset system...

  10. Analysis of an Explosion Accident of 500 kV SF6 Circuit Breaker%一起500kV SF6断路器爆炸事故分析

    Institute of Scientific and Technical Information of China (English)

    郭树永

    2013-01-01

    This paper introduced an explosion accident of 500 kV SF6 circuit breaker in Xingren converter station, the structure of breaking unit,theory of interruption and action process about the SF6 circuit breaker was discussed, combining with the practical situation, all possible factors of the accident is analysised.Finally the reasons of the accident were presented:the shafts in the T-mechanism were displaced caused by the two missing bearings after many opening and closing,a pin had sheared off by the excessive forces and finally breaked off from the mechanism; the arcing contacts could not contact after closing operation, a stable short arc was initiated across the arcing contacts,the pressure inside the breaking unit increased for the heated gas.At last,the interrupter exploded and led to a grid short circuit accident. To avoid similar accidents,this paper provided the corresponding proposal about quality control of manufacturers.%针对兴仁换流站发生的一起500 kV SF6断路器爆炸事故,根据SF6断路器的灭弧室结构、开断原理及动作过程,结合现场实际情况,分析了事故的各种可能因素.确定了该起事故的原因为T型机构箱内转轴的轴承漏装,多次分合后转轴逐渐移位,并磨损了传动机构的1个销子,最终导致销子脱落;断路器合闸后弧触头不能接触,出现稳定短电弧导致灭弧室内气体发热,压力升高,灭弧室发生爆炸导致电网短路事故.对制造厂的质量控制提出了建议,以避免类似事故发生.

  11. Application of Failure Mode and Effects Analysis in Motor Protection Circuit Breaker Design%失效模式与后果分析在电动机保护断路器设计中的应用

    Institute of Scientific and Technical Information of China (English)

    蒋晓锋

    2015-01-01

    针对传统失效模式与后果分析(FMEA)在面对复杂系统时存在的系统描述不清的问题,提出自上而下的功能建模方法。以电动机保护用断路器为例,利用DFMEA 自上而下分析了产品各级系统之间的影响后果、失效模式、起因,并采取针对性的纠正措施以及实施后的效果验证。结果验证能有效控制设计风险。%The traditional Failure Mode and Effects Analysis(FMEA)method can not describe the complex system clearly.Aiming at the problem,the functional modeling method of top-down was put forward.Taking a motor protection circuit breaker for example,the relations of failure modes,effects and causes of various levels were analyzed based on DFMEA top-down method,and the pertinent corrective actions were applied and the action results were verified.

  12. 船用交流中压断路器开断性能相关参数分析%Analysis of Parameters for Breaking Performance of Marine Medium Voltage AC Circuit Breakers

    Institute of Scientific and Technical Information of China (English)

    杨青

    2013-01-01

    According to the characteristics of marine medium voltage power system,the parameters closely related to the breaking performance of medium voltage AC circuit breaker were analyzed.It is shown that the key performance parameters in land standards,such as rated breaking current,making current,power frequency recovery voltage,transient recovery voltage,electrical life and so on,basically meet the marine requirements after conversion. But there are also some individual parameters need to be studied further to decide.%根据船舶中压电力系统的特点,对中压断路器开断性能密切相关的参数进行了分析。结果表明,陆用标准中额定短路开断电流和关合电流、工频恢复电压和瞬态恢复电压、电寿命等参数经过换算、折算,基本上符合船用要求,个别参数是否合适有待进一步研究。

  13. The Theory and Application of A New Appointment Protection of Circuit Breakers%低压断路器的一种新型预约保护功能的原理及应用

    Institute of Scientific and Technical Information of China (English)

    贺贵兵; 雷震宙

    2014-01-01

    本文介绍了低压断路器控制器所具有的实际应用功能,包括测量功能、保护和报警功能、自诊断功能等等。着重阐述了预约保护功能的原理、实现方式以及与原有特性参数修改的差异。对预约保护功能在低电压穿越、负载监控及双电源回路中的具体应用进行了分析和说明。%This paper describes the practical applications of controller of circuit breakers that includes measurements, protection and alarm, self-diagnosis and so on. The article focuses on the principle of protection reservation, implementation and the differences of changing parameters. The application of reservation protection in the area of low voltage ride trough, load monitoring and dual power loop is analyzed and described.

  14. Dynamic dielectric recovery characteristics of hybrid circuit breaker based on vacuum interrupter and SF6 interrupter in series%基于真空灭弧室与SF6灭弧室串联的混合断路器动态介质恢复特性

    Institute of Scientific and Technical Information of China (English)

    程显; 廖敏夫; 段雄英; 邹积岩

    2012-01-01

    论述了基于真空灭弧室和SF6灭弧室串联的混合断路器开断能力提高的原理,分析了混合断路器两灭弧室的介质恢复过程.结合混合断路器开断能力提高的机理提出了混合断路器对其操动控制机构的要求,设计了一种基于真空灭弧室与SF6灭弧室串联的光控模块式混合断路器实验模型.实验模型能满足分析混合断路器中真空灭弧室与SF6灭弧室在不同时刻协同动作开断容量增益特性的要求,其协同动作时间分散性在微秒级.实验对比了SF6断路器与基于相同SF6灭弧室串联真空灭弧室的混合断路器短路电流开断能力,证明在不增加SF6气体使用量的前提下,混合断路器具有比SF6断路器更加优越的开断能力.%The principle of breaking capacity improvement of hybrid circuit breaker with serial vacuum interrupter and SF6 interrupter is discussed and the dielectric recovery process of two interrupters is analyzed. Based on the improvement of breaking capacity,the requirements of hybrid circuit breaker for its control mechanism are proposed. The experimental model of hybrid circuit breaker based on optical control modules is designed,which meets the research requirement for the breaking capacity gain characteristic of coordinating operation at different moments between vacuum interrupter and SF6 interrupter, and the time dispersion is microsecond level. Experimental results show that,if the usage of SF6 gas is same,the breaking capacity of hybrid circuit breaker is higher than that of SF6 circuit breaker.

  15. 广东地区变电站出线断路器侵入波过电压实时数字仿真分析%Realtime Digital Simulation of Lightning Surge Intrusion on Outlet Circuit Breakers of Substations in Guangdong Region

    Institute of Scientific and Technical Information of China (English)

    彭向阳; 姚森敬; 郭婷; 周文俊

    2012-01-01

    General situation of substation outlet circuit breaker faults caused by lightning surge intrusion occurred in Guangdong region before the installation of outlet arrester is described, and it is clarified that the lightning surge intrusion protection for outlet circuit breakers during its reclosure must be reinforced, i.e., outlet arresters must be installed in front of outlet circuit breakers. Utilizing real-time" digital simulator (RTDS), the overvoltage caused by lightning surge intrusion during the reclosure of outlet circuit breaker is simulated, and the effect of enhancing insulation level of transmission line and the protection result of adding outlet arresters are evaluated as well. Simulation results show that after outlet arrester is installed, although the insulation level of transmission line is strengthened considerably, dangerous lightning surge intrusion will not appear on outlet circuit breaker, thus the operating condition of lightning protection for substation can be effectively improved.%介绍广东地区变电站未安装出线避雷器前雷电侵入波事故概况,明确了必须加强出线断路器重合闸期间的侵入波保护,即应安装出线断路器前置避雷器。利用实时数字仿真器(real.timedigitalsimulator,RTDS)分析变电站出线断路器开断期间雷电侵入波过电压,并对加强线路绝缘的影响以及出线避雷器的保护效果进行评估。计算结果表明:变电站装设出线避雷器后,即使大幅提高输电线路绝缘水平,也不会在出线断路器产生危险的雷电侵入波过电压,能有效地改善变电站防雷运行工况。

  16. FAULT ANALYSIS & TREATMENT OF THE VACUUM CIRCUIT BREAKER ON 66 kV STRAIGHT POWER SUPPLY SUBMERGED ARC FURNACE%66 kV直供电矿热炉用真空断路器的故障分析及处理

    Institute of Scientific and Technical Information of China (English)

    谢红亮

    2016-01-01

    高压真空断路器是利用“真空”(气压为0.01~0.000001 Pa)灭弧的一种断路器,是电力线路中重要的一次控制设备,不仅能通断正常负荷电流,而且还能接通和承受一定时间的短路电流,并能在保护装置作用下自动跳闸,切除短路故障,具有体积小、重量轻、动作快、安全可靠等优点,适用于频繁操作的场所。%High voltage vacuum circuit breaker is a kind of breaker which takes advantage of“vacuum”to cut off arc discharge. It is a kind of important one time controlling device in circuit. It can not only break-make normal current, but also switch on and bear some time short circuit current. In the same time, it can also automatic trip under protective device and cut the short circuit fault. It is suitable for places of operation frequently.

  17. 30 CFR 75.900-2 - Approved circuit schemes.

    Science.gov (United States)

    2010-07-01

    ... device installed in the main secondary circuit at the source transformer may be used to provide undervoltage protection for each circuit that receives power from that transformer. (c) One circuit breaker may... overcurrent protection for the smallest conductor. (d) Circuit breakers with shunt trip, series trip...

  18. 特高压奉贤换流站最后断路器保护调试异常原因及改进建议%Abnormal Causes and Improved Suggestions of Last Circuit Breaker Protection during Test Process in Fengxian UHVDC Converter Station

    Institute of Scientific and Technical Information of China (English)

    张婷; 张小亮

    2012-01-01

    The tripping equipment of the last circuit breaker is an important control device of the DC system in HVDC converter station. Firstly, this paper introduces the basic principle of the last circuit breaker protection in Fengxian HVDC converter station. Then, aiming at the abnormal condition of protection failure in system operation period, we analyze parameters variation curves in the field fault recording figure, and it is concluded that protection failure is caused by too small transmitted power. Based on the analysis, we propose an improved suggestion to test the last circuit breaker protection during system operation under low power condition, which can also help to avoid device damage.%鉴于高压直流输电系统逆变站最后断路器跳闸装置是非常重要的换流站直流系统控制设备,介绍了奉贤特高压换流站最后断路器保护的基本原理,针对系统调试期间该保护未正常动作的异常情况,通过分析现场故障录波图中各参数变化曲线得出调试时最后断路器保护未正确动作的原因是由于系统输送功率过小所致,并提出了相应的改进建议,使得在低功率系统调试时能起到测试最后断路器保护的作用,同时避免了设备损坏.

  19. Mechanical Fault Diagnosis of High Voltage Circuit Breakers with Unknown Fault Type Using Hybrid Classifier Based on LMD and Time Segmentation Energy Entropy

    Directory of Open Access Journals (Sweden)

    Nantian Huang

    2016-09-01

    Full Text Available In order to improve the identification accuracy of the high voltage circuit breakers’ (HVCBs mechanical fault types without training samples, a novel mechanical fault diagnosis method of HVCBs using a hybrid classifier constructed with Support Vector Data Description (SVDD and fuzzy c-means (FCM clustering method based on Local Mean Decomposition (LMD and time segmentation energy entropy (TSEE is proposed. Firstly, LMD is used to decompose nonlinear and non-stationary vibration signals of HVCBs into a series of product functions (PFs. Secondly, TSEE is chosen as feature vectors with the superiority of energy entropy and characteristics of time-delay faults of HVCBs. Then, SVDD trained with normal samples is applied to judge mechanical faults of HVCBs. If the mechanical fault is confirmed, the new fault sample and all known fault samples are clustered by FCM with the cluster number of known fault types. Finally, another SVDD trained by the specific fault samples is used to judge whether the fault sample belongs to an unknown type or not. The results of experiments carried on a real SF6 HVCB validate that the proposed fault-detection method is effective for the known faults with training samples and unknown faults without training samples.

  20. Electric Life of Vacuum Circuit Breaker Considering High-speed Trains Passing Neutral Sections%高速列车过分相段下真空断路器的电寿命研究

    Institute of Scientific and Technical Information of China (English)

    李天鸷; 吴广宁; 欧阳乐成; 高国强; 王万岗

    2012-01-01

    For the vacuum circuit breaker (VCB) breaking frequently in high-speed railway, contacts were repeatedly corroded, and tips, coarsenesses and reduction of vacuum degree of diffusing metal vapor were caused by arc during breaking. The experimental program was proposed of characterizing VCB electric life by measuring contact resistance of normal current under different breaking number. Meanwhile, the characteristics of withstanding impulse voltage and frequency voltage under different breaking number were obtained. Studies have shown that the contact resistance was initially increasing with the increase of breaking number, and after that, contact resistance was unchanged; in the initial testing period, the transient recovery voltage could not cause reignition of arc, but multiple reignitions of arc would happen possibly with working in a long term, although the gas of interrupter could not be breakdown by working-frequency voltage.%针对高速列车真空断路器(VCB)在列车运行中处于频繁开断的状态,开断过程中电弧反复烧蚀触头产生尖端、毛刺、金属蒸汽,扩散的金属蒸汽又使灭弧室真空度降低,首次提出了通过测量VCB在分断不同次数正常电流下接触电阻表征其电寿命的试验方法,并得到了不同分断次数下耐受冲击电压和工频工作电压的特性.研究表明:VCB初期接触电阻随分断次数增加而增加,之后接触电阻基本保持不变;在VCB使用初期瞬态恢复电压不能导致电弧重燃,长期工作后可能导致电弧多次重燃,但即使长期工作后工频工作电压仍不能击穿灭弧室.

  1. Review of the Numerical Prediction Method for the Interruption Capability of SF6 Circuit Breakers%SF6断路器开断能力数值预测方法研究综述

    Institute of Scientific and Technical Information of China (English)

    牟京卫; 郭瑾; 李兴文; 陈冰; 辛昭昭; 游一民

    2012-01-01

    Numerical prediction methods both for the thermal interruption capability and the dielectric recovery capability of SF6 gas circuit breaker (GCB) are reviewed in the paper. The arc conductance 200 ns (G200) before current zero is a key parameter of the thermal interruption capability of the GCB. The magneto-hydro-dynamics (MHD) model is applied during the arcing process and the Mayr model is 'adopted near current zero to evaluate the Gxo- Then the arc time constant and the arc power loss coefficient could be obtained. To evaluate the dielectric recovery capability of GCB, the reduced electric field strength Ec has to be calculated everywhere in the interrupter after current zero. The reduced critical electric filed strength £a has to be computed as well. The probability of the dielectric breakdown after current zero can be judged by the comparison of the £a and Ec. It has to be indicated that the proposed numerical prediction methods are still need to be verified by further experimental efforts.%综述了SF6断路器极限开断能力以及介质开断能力的数值预测方法的最新研究进展.电流过零前200 ns的电弧电导(G200)是判断断路器热开断能力的一个重要参数,为计算G200,对电弧特性进行模拟,在燃弧阶段采用磁流体动力学模型,而在接近电流零区采用Mayr模型,从而建立相应的电路模型来确定电弧时间常数和电弧功率损耗系数等参数,以分析高压断路器的热开断能力.为判断电击穿能力,需要根据电弧过零时灭弧室内的每一点的压力和温度值,确定对应点的临界击穿场强分布Ec,同时计算在暂态恢复电压作用下灭弧室内的电场分布Ea,然后通过比较灭弧室内各处Ea和Ec的值,就可以判断出灭弧室内不同区域电击穿几率的大小.

  2. Condition-Based Assessment Model of MV Vacuum Circuit Breaker With Radar Chart Method%中压真空断路器状态的雷达图法评估模型

    Institute of Scientific and Technical Information of China (English)

    李海英; 冯冬; 宋建成

    2013-01-01

      The overall online healthy assessment is the best strategy for the balance between the economy and the reliability of power equipment, this paper focuses on the online healthy condition-based assessment model of the medium voltage (MV) vacuum circuit breakers (VCB). Various performance indices are firstly proposed to assess the VCB’s condition by analyzing the fault characteristics of its main components. Then, the perfection degree is defined to make the sampling data normalized. Based on indices coupling relationships, the weights are determined with analytic hierarchy process (AHP). The entropy is employed to quantify the nonequilibrium impairment of all indices. Finally, an improved radar chart method with eigenvalue calculating algorithm is applied to the VCB’s condition assessment. In the method, the reference samples considering the impairment speed in thresholds design, especially the nonequilibrium entropy are incorporated to ensure VCB’s safety early warning adequately and timely. The test results on monitoring 10 kV VCB show that the model is concise, intuitive and feasible.%  电力设备健康状态的全面在线评估是平衡经济性和可靠性的最佳策略。建立中压真空断路器的评估模型:通过分析断路器各主要组成部分的故障特征,构建健康性能评估指标集;定义完好度概念,进行指标的归一化处理;剖析指标的耦合关系,采用层次分析法确定指标权重;引入熵值法,量化指标劣化的非同步性;建立一种基于雷达图法的图形化状态评估方法,并在定量计算中引入参考样本和指标不平衡值,特别是参考样本区间的设计纳入指标的劣化速度特征,确保了劣化预警的充裕性和及时性。10 kV真空断路安全状态评估表明,该模型简单、直观、实用性强。

  3. 环网式三端直流输电系统及直流断路器应用的分析与仿真%Analysis and Simulation of Ring-Shaped Three-Terminal HVDC Power Transmission System and Annlication of DC Circuit Breakers

    Institute of Scientific and Technical Information of China (English)

    方进; 邓珂琳; 温家良

    2012-01-01

    分析了多端直流输电系统的基本原理,利用PSCAD/EMTDC软件建立了多端直流输电系统仿真模型,并建立了含直流断路器的多环网式多端直流输电系统模型,通过仿真研究了直流断路器开断直流输电线路的过程,分析直流断路器在环网式多端直流输电系统中的作用。对直流断路器切除环网式三端直流输电系统一条输电线路的过程及切除故障换流站分别进行了仿真分析。仿真结果表明,当利用直流断路器切除环网式多端直流输电系统的一条输电线路时,输电线路的电流重新分配,能保证功率输送的连续性。在这种情况下,对各个换流站输出或输入的功率影响不大,对与直流系统连接的交流输电网影响很小。当切除故障换流站后,该系统最大限度地保持功率传输及电流的有效分配,保持稳定运行。%Basic principles of multi-terminal direct current (MTDC) power transmission system are analyzed, and utilizing PSCAD/EMTDC software a model of MTDC power transmission system and a model of multi ring-shaped MTDC power transmission system containing DC circuit breakers are built. The process of switching off a DC transmission line by DC circuit breakers is simulated and researched, and the action of DC circuit breakers in multi ring-shaped MTDC transmission system is analyzed. The process of switching off one of transmission lines as well as the process of switching off a faulty converter station in three-terminal DC transmission system by DC circuit breakers are simulated respectively. Simulation results show that when one of DC transmission line in ring-shaped MTDC transmission system is switched off by DC circuit breakers, the currents in DC transmission lines are redistributed to ensure the continuity of power transmission. Under such a condition, the affection on input or output power of each converter station is not notable, and the affection on AC

  4. Power System Fault Diagnosis Considering Absence of Alarm Messages of Circuit Breakers on the Border of Outage Area%停电区域边界断路器信息缺失时的电网故障诊断

    Institute of Scientific and Technical Information of China (English)

    王磊; 陈青; 李天友; 高湛军; 李兆飞

    2013-01-01

      当电网中的元件发生故障,相关保护会跳开断路器以切断故障电流,最终形成一个或多个停电区域。如果将可疑故障元件限定在停电区域内,故障诊断程序的效率会得到很大的提升。然而在调度中心收到的跳闸断路器信息有缺失的情况下,由于无法形成停电区域,故障诊断程序只能对电网中所有元件逐一进行诊断,并且还容易造成对故障元件的漏判。针对断路器报警信息丢失的情况,从图论角度出发,以点割集算法为基础划分出多个可能包含故障元件的无源区域,然后通过skyline多目标优化查询方法,对这些无源区域按可疑元件查准率由高到低的顺序进行排列,并提供给故障诊断程序,保证了诊断速度的同时,能够防止故障元件的漏判。最后使用Petri网为诊断工具,以故障诊断算例验证了该方法的有效性。%When a fault takes place on a section in a power grid, the corresponding protective relays will trip the related circuit breakers to cut off the fault current. As a result, one or more outage areas would be formed. If the faulty section is restricted in the outage area, the efficiency of fault diagnosis program will be greatly promoted. On the other side, if the control center can not receive the whole alarm message of circuit beakers, all of the sections must be diagnosed because the outrage area can not be gotten. Furthermore, wrong diagnosis results may be gotten because of the missing of alarm messages. Given this back ground, based on graph theory, one or more outrage area can be partitioned by cut-set of nodes. Multi-objective optimization method skyline query was applied to sort the outrage area decreasingly based on the precision rate of fault section. The developed diagnosis method could make the diagnosis program much faster, and can insure the fault section will not be omitted. Petri net was applied as the diagnosis tool

  5. 基于分形理论的低压断路器三相合闸同期性振动信号特征分析%Vibration signal feature analysis of switching synchronization for low voltage circuit breaker based on fractal theory

    Institute of Scientific and Technical Information of China (English)

    石敦义; 缪希仁; 郭谋发

    2014-01-01

    在综述现有断路器机械故障振动信号研究方法的基础上,提出了一种经验模态分解( EMD)和分形理论相结合的方法用于提取低压断路器振动信号的特征量,并以典型的三相合闸不同期性低压断路器故障为对象,研究了EMD结合分形维数的故障振动信号特征分析,且给出以分形维数均方根作为故障特征量的实验仿真数据结果。首先,利用EMD方法对低压断路器的振动信号进行分解,得到若干个本征模态函数( IMF);其次,对振动信号以及各IMF分量求分形维数及其均方根,作为低压断路器振动信号的特征量。通过对低压断路器三相合闸不同期性模拟故障振动信号处理,对比其不同状态下的分形维数及其均方根的变化规律,表明该方法不仅可作为低压断路器三相同期性故障诊断的判据,且可应用于断路器其他各类机械故障的振动信号特征的提取分析。%By reviewing the existing methods for mechanical fault vibration signal of circuit breaker, a method that combines EMD ( Empirical Mode Decomposition) with fractal theory is presented for extracting feature value from vibration signal of low voltage circuit breaker. Based on the typical object of low voltage circuit breaker for three⁃phases switching asynchronism, not only the fault vibration signal feature is analyzed by the method of EMD com⁃bined with fractal dimension, also the fault feature value of experimental and simulation data is provided with the root⁃mean⁃square of fractal dimension. Firstly, EMD is used to decompose the vibration signal into a number of in⁃trinsic mode functions ( IMF) . Secondly, the root⁃mean⁃square of fractal dimension is calculated for the vibration signal and it’ s every order IMF as the vibration signal feature value. Finally, the changing rule for the root⁃mean⁃square of fractal dimension to simulated failure vibration signals is

  6. Text Mining Technique and Application of Lifecycle Condition Assessment for Circuit Breaker%文本信息挖掘技术及其在断路器全寿命状态评价中的应用

    Institute of Scientific and Technical Information of China (English)

    邱剑; 王慧芳; 应高亮; 张波; 邹国平; 何奔腾

    2016-01-01

    In power grids,operating and maintaining engineers have recorded plenty of texts or logs during maintaining and inspecting activities.These textual data contain abundant asset health information.So far,however,few researches,if any, have studied text mining techniques in the power grid.We take the circuit breaker (CB) as a case in point to establish a framework of text mining-based lifecycle condition assessment.Firstly,the key issues of text mining and lifecycle condition assessment models are listed based on reviewing the research of CB condition assessment.Then,use is made of the framework including a hidden Markov model (HMM)-based text preprocessing and vectorizion,self-interval searching k-nearest neighbor (KNN)-based text classification,and a proportional health-index fusion model (PHFM).Finally,we have collected real textual data from a certain power company to demonstrate an example that shows the text mining technique could learn similar defects from other assets by itself,and PHFM shows historical data stream and lifecycle health index much more rigorously.%电网企业记录了大量故障与缺陷中文文本,这些文本蕴藏了丰富的设备健康信息。但迄今为止,鲜有电力领域的文本信息挖掘技术研究。以断路器全寿命状态评价为应用研究背景,探索了电网中文文本挖掘方法。首先,根据断路器状态评价的研究现状,提出了构建文本挖掘与全寿命状态评价模型的关键问题。然后,构建了包含文本挖掘信息的全寿命状态评价模型,通过基于隐马尔可夫法(HMM)的文本预处理与向量化、自主区间搜索 k 最近邻(KNN)算法的文本分类和比率型状态信息融合模型完成了断路器全寿命健康状态指数的展示。最后,采用某电网公司实际缺陷文本构建算例。算例表明,文本挖掘技术实现了相似缺陷的相关性学习,比率型信息融合模型能更全面真实地展示健康状态评价的历史流。

  7. Research on a New Fault Identification Technology for High Voltage Circuit Breaker Actuator%新型高压断路器操动机构故障识别

    Institute of Scientific and Technical Information of China (English)

    徐成龙; 于虹; 董良太; 刘泽坤; 杜必强

    2014-01-01

    By use of high-speed,high-resolution cameras to capture the breaker sub-gate process transmission components operat-ing condition,and acquire the displacement,spindle rotation and angle parameters in the process of breaker operating by using im-age analysis and recognition technology,and then calculate the closing time,dynamic contact trip as well as the speed of movement�This method radically innovative breaker mechanical properties test methods and improve the test accuracy and speed of parameters;Combined with analysis of sound, vibration, spectral characteristics and divide-shut brake coil current in the operation process,found actuator potential failures and analyze the fault type,improve the accuracy of operation state judgment,lay the foundation for the breaker online fault monitoring and condition based maintenance.%利用高速、高分辨率摄像机捕捉断路器合分闸过程传动部件的运行状况,采用图像分析和识别技术获取断路器操动中传变部件运动位移、主轴转动过程及角度参数,计算分合闸时间、动触头行程、运动速度,从根本上革新断路器机械特性测试方法,提高参数测量精度和速度;再结合操动过程中声、振动的频谱特征分析、操作中分合闸线圈电流的分析,发现操动机构潜在故障,并分析故障类型,提高对运行状态判断的准确性,为断路器在线故障监测和状态检修奠定了基础。

  8. Simulation on Interaction of Vacuum Arc and SF6 Arc in Hybrid Circuit Breaker During High-current Interruption%混合断路器大电流开断过程中真空电弧与SF6电弧相互作用的仿真

    Institute of Scientific and Technical Information of China (English)

    程显; 段雄英; 廖敏夫; 陈建华; 邹积岩

    2012-01-01

    真空断路器和SF6断路器串联的混合断路器,可有效利用真空和SF6气体两种介质不同的灭弧特性实现更大短路电流的分断。为研究两种电弧的相互任用,运用ATP软件及其TACS工具建立了系统实验仿真平台、12kV真空断路器与40.5kV SF6断路器的电弧模型;将仿真结果与实验波形结合通过数学方法分别求得实用的真空电弧和SF6电弧模型参数;搭建了实用真空电弧模型与SF6电弧模型串联的混合断路器模型。通过设定不同的系统仿真参数,研究开断过程中真空电弧和SF6电弧的相互作用及真空断路器与SF6断路器的分压关系;分析两断路器不同时刻分断的协同特性与介质恢复过程;量化研究混合断路器的断流容量增益特性。仿真结果证明,真空断口首先承担恢复电压有利于SF6断口的介质强度恢复;两断口间的电压分布关系主要由电弧电阻与断口间电容决定;在不增加SF6气体使用量的情况下混合断路器具有比SF6断路器更大的断流能力。研究结果为大容量混合断路器的设计提供了理论依据。%Hybrid circuit breaker with vacuum interrupter and SF6 interrupter in series makes the best use ot different are extinguishing characteristics of vacuum arc and SF6 arc to achieve high-current interruption. To study the interaction between vacuum arc and SF6 arc, we established a system simulation platform, a vacuum arc model (12 kV), and a SF6 arc model{40. 5 kV) by alternative transients program(ATP) and its transient analysis of control systems (TACS). Combining with the experimental oscillograph traces, we obtained practical model parameters of the vacuum arc and the SF6 arc; and established a hybrid circuit breaker model by connecting the vacuum arc model and the SF6 arc model in series. To study interactions and voltage distribution relations between vacuum arc and SF6 arc during current interruption process, we analyzed the

  9. Implementation of Reliable Interruption of 50kA Direct Current Circuit Breakers Based on High Parameters Thyristors%基于高参数晶闸管实现50kA直流断路器的可靠开断

    Institute of Scientific and Technical Information of China (English)

    楼晓峰; 胡醇; 董涛; 杨孝志; 陈超

    2015-01-01

    Introduction was made to the application of the current hedge method in the reliable interruption of direct current (DC) circuit breakers, and analysis was made to the operating principle of the current hedge method and the technical problems in the test process. Through the co-use of the thyristor devices with high parameters, saturated reactors and synchronous operating mechanism, the reliable and accurate interruption of DC circuit breakers were achieved. The result shows that the key point is how to accurately seize the hedge point of two circuits in the interruption process by controlling the synchronous operating mechanism and trigger thy-ristor devices. The current hedge method takes full advantage of the thyristor devices, ensuring the accuracy of the whole interruption process. The di/dt of hedge current at current zero and the rising amplitude of peak reverse voltage have been suppressed effectively by saturated reactors, and the thyristor devices have also been protected. The whole circuit costs economically and largely make up for the shortcomings of the traditional methods.%介绍了电流对冲法在直流断路器可靠开断方面的应用,分析了电流对冲法的工作原理和试验过程中遇到的技术问题,通过高参数晶闸管器件、饱和电抗器和同步操作机构的配合使用,实现了直流断路器精确、可靠的开断,结果表明:通过控制同步操作机构和触发晶闸管器件来精确把握开断过程中两个回路的对冲点是关键,电流对冲法充分利用了晶闸管器件的优点,保证了整个开断过程的精确性;饱和电抗器有效抑制了对冲电流过零时的di/dt和反峰电压的增长,保护了晶闸管器件;整个回路造价经济,很大程度上弥补了传统试验方法中的不足.

  10. 24 CFR 3280.804 - Disconnecting means and branch-circuit protective equipment.

    Science.gov (United States)

    2010-04-01

    .... Electrical distribution panels containing circuit breakers shall also be dead-front type. (c) Disconnecting... point of entrance of the supply cord or conductors into the manufactured home. The main circuit breakers... floor level of the manufactured home. (e) A distribution panelboard employing a main circuit...

  11. A Study on Main Breaker for Quench Protection of HT-7U Toroidal Superconducting Tokamak

    Institute of Scientific and Technical Information of China (English)

    许留伟; 刘小宁

    2002-01-01

    This paper proposes a quench protection project of HT-7U toroidal superconducting tokamak through a forced commutation analysis of DC circuit breaker (DCCB) paralleling fuse.Based on the requirement of quench protection, main parameters are selected. Experimental results demonstrate the validity of this proposed project.

  12. A study on Main Breaker for Quench Protection of HT—7U Toroidal Superconducting Tokammak

    Institute of Scientific and Technical Information of China (English)

    许留伟; 刘小宁

    2002-01-01

    This paper proposes a quench protection project of HT-7U toroidal superconducting tokamak through a forced commutation analysis of DC circuit breaker(DCCB) paralleling fuse.Based on the requirement of quench protection.Amin parameters are selected.Experimental results demonstrate the validity of this proposed project.

  13. Mechanical Fault Diagnosis of High Voltage Circuit Breakers Utilizing Zero-phase Filter Time-frequency Entropy of Vibration Signal%采用振动信号零相位滤波时频熵的高压断路器机械故障诊断

    Institute of Scientific and Technical Information of China (English)

    常广; 王毅; 王玮

    2013-01-01

    To obtain the mechanical condition information contained in vibration signals of high voltage circuit breakers with small calculation cost, a zero-phase filter time-frequency entropy method was proposed for condition feature extraction. The time-frequency distributions of vibration signals were analyzed via wavelet packet decomposition method. The frequency intervals and the time intervals of the time-frequency plane were calculated based on the marginal spectrum and its instantaneous energy density level. According to the frequency intervals, different frequency components were separated from vibration signals using zero-phase digital filters. According to the time intervals, frequency components were segmented into time subsections. Entropy of a frequency component was constructed adopting the integral of the amplitude envelope of each time subsection, and all entropies composed a time-frequency entropy vector. Through these measures, the characteristics of a time-frequency plane were quantified by the time-frequency entropy vector. Simulative experiments on a vacuum circuit breaker were conducted and vibration signals of normal condition, friction in solenoid, loose flexible connection and defective insulating tie were collected. Support vector machine classifiers were introduced for fault diagnosis of different conditions and an accuracy of 90% was gain. The results verify the feasibility of the mechanical fault diagnosis approach for high voltage circuit breakers employing the zero-phase filter time-frequency entropy scheme.%为了以较少的计算量从高压断路器振动信号中获取机械状态信息,提出一种零相位滤波时频熵方法.通过小波包方法分析高压断路器振动信号的时频分布,并利用边际谱和瞬时能量密度计算时频平面的划分间隔.依据频带间隔,采用零相位数字滤波器提取频带分量;依据时间间隔,将各频带分量划分为多个子时间段.用子时段幅值包络的积分构

  14. An On-line Identification of Equipment Risk for 3/2 Circuit Breaker Connections%针对电网3/2接线方式的设备风险在线辨识方法

    Institute of Scientific and Technical Information of China (English)

    闪鑫; 戴则梅; 曹路; 汪德星

    2012-01-01

    3/2接线方式由于具有供电可靠性高、运行调度灵活、倒闸操作方便等优点,在500kV厂站和部分220kV枢纽变电站得到了广泛应用。但是,该接线方式在一次设备或开关处于检修方式下时,某些故障模式可能会造成多个设备的停电。基于网络拓扑分析和保护动作逻辑的设备风险在线辨识技术,能够针对3/2接线方式下的一次设备或开关检修,自动识别出具有N-2以上停电设备的潜在故障模式,提醒调度运行人员;同时,结合静态安全分析、动态安全分析以及检修计划,实现大电网的设备风险在线防控。%Owing to lots of advantages such as high reliability for power supply,flexible operating and dispatching mechanism and convenient transfer switching,etc,the 3/2 connection mode has been widely put into operation in 500 kV power stations and some 200 kV load-center substations.However,many equipments may be subjected to power cut caused by some fault modes as long as the connection mode is linked with primary equipment or the breaker under prophylactic overhaul.Using on-line identification technology of equipment risk based on network topology analysis and operation logic for protection,it is able to automatically identify the latent fault mode concerning N-2 or more power-failure equipments for primary equipment or breaker overhaul under 3/2 connection mode,and reminds relevant dispatching working staff.In the meantime,through the combination of static and dynamic security analysis and maintenance schedule,it will achieve on-line prevention and control mechanism for equipment risk in large power grid.

  15. 330 MW火电机组发变组出口断路器跳闸原因分析%Trip cause analysis for outlet circuit breaker trip of generator-transformer unit in 330 MW coal-fired power plant

    Institute of Scientific and Technical Information of China (English)

    余民

    2015-01-01

    针对一起330 MW火电机组发变组出口断路器在无任何保护动作情况下的跳闸故障,采用逐步排查法,通过现场模拟实验,找出了故障的原因,提出有效解决办法并制定了防范措施.应用结果表明:改进措施消除了机组存在的安全隐患,确保了机组的长周期安全运行.%Aiming at an accident of generator-transformer unit outlet circuit breaker trip without any protection device act in 330 MW coal-fired power plant,using gradual elimination method and field simulation test,finds out the causes of the trip,puts forward effective solution and preventive measures. The application result shows that the improved measures eliminate the hidden safety trouble,guarantee long periodic safe operation of the 330 MW coal-fired power generation unit.

  16. LW10B-252型断路器机构油压对同期性及分、合闸时间的影响%Mechanism Oil-pressure's Effect on Closing/opening Simultaneityand Time of LW10B-252 Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    石锋杰; 郭琳; 李芳

    2012-01-01

    Non-simultaneous opening or closing of the three phases of circuit breaker can lead to a short time open-phase operation in power system, and perhaps causes neutral point voltage displacement or overvoltage, prolong thereclosing time delay, and is disadvantage to the stability of power system. This paper analyses the relationship betweenoil-pressures in the latching range of hydraulic system and closing/opening time, and the effect on the opening or closingsimultaneity.%分、合闸不同期,将使系统在短时间内处于非全相运行,可能会引起中性点电压位移、过电压、加大重合闸时间,对系统稳定性不利.本文对LW 10B-252型断路器进行试验,分析了液压系统油压在闭锁范围内和分合闸时间的关系以及对同期性分合闸的影响.

  17. The wave vane - A device to measure the breaker angle

    Digital Repository Service at National Institute of Oceanography (India)

    Chandramohan, P.; Nayak, B.U.; Anand, N.M.

    11 February 1992; accepted after revision 11 November 1992) ABSTRACT Estimation of the breaker angle in the littoral environmental observation (LEO) programme is still based on visual methods and therefore is subjective in nature. In the absence... directional wave gauge at a considerable cost. For economic and practical considerations, visual measurements on the breaker height, the breaker period and the breaker angle are generally made in the LEO pro- gramme. The breaker height is recorded...

  18. 30 CFR 56.12001 - Circuit overload protection.

    Science.gov (United States)

    2010-07-01

    ... § 56.12001 Circuit overload protection. Circuits shall be protected against excessive overload by fuses or circuit breakers of the correct type and capacity. ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuit overload protection. 56.12001...

  19. 30 CFR 57.12001 - Circuit overload protection.

    Science.gov (United States)

    2010-07-01

    ... Electricity Surface and Underground § 57.12001 Circuit overload protection. Circuits shall be protected against excessive overloads by fuses or circuit breakers of the correct type and capacity. ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Circuit overload protection. 57.12001...

  20. 断路器的操作机构分析探讨%Discussion and analysis on operating mechanism of breaker

    Institute of Scientific and Technical Information of China (English)

    黄静

    2012-01-01

    断路器必要的动作次数是极无规则的,接受指令时的动作必须准确可靠,从高频度到低频度的广泛范围内,都必须具有高度的可靠性。%The necessary action frequency of circuit breaker was extremely irregularity, while the breaker was accepting instruction action which must be accurate and reliable. From high frequency to low frequency wide range, the action of breaker must have a high degree of reliability.

  1. Medium voltage SF6 switch rooms with switch breakers; Cubiculos de media tensao em SF6 com disjuntores

    Energy Technology Data Exchange (ETDEWEB)

    Matias, Marcos [Schneider Electric Brasil, Sao Paulo, SP (Brazil)

    1999-07-01

    This paper describes the technology using SF6 as breaking gas and the application in medium and high voltage switch rooms. The paper also describes the metal clad panel, the ring main unit, the medium voltage, and the panel saw and circuit breakers with SF6.

  2. Constructing Breaker Sequence based System Restoration Strategy with Graph Theory

    OpenAIRE

    Peng, C.; Qin, Z.; Wang, C.; Hou, Y

    2014-01-01

    This paper has proposed a mapping approach to serve as an interface between the branch-bus model and the breaker-based model. In order to find the specific optimal operation for breakers in substations according to the restoration strategies, firstly, the paper has established the breaker-based model for the substation by using graphic theory, and then the optimal operation sequence for breakers has been figured out by adopting Dijkstra algorithm. Finally, a case study for a realistic power s...

  3. A threshold for the Maker-Breaker clique game

    NARCIS (Netherlands)

    Muller, Tobias; Stojakovic, Milos

    2014-01-01

    We study the Maker-Breaker k-clique game played on the edge set of the random graph G(n, p). In this game, two players, Maker and Breaker, alternately claim unclaimed edges of G(n, p), until all the edges are claimed. Maker wins if he claims all the edges of a k-clique; Breaker wins otherwise. We de

  4. Megavolt nanosecond generator with semiconductor current breaker

    CERN Document Server

    Bushlyakov, A I; Rukin, S N; Slovikovskij, B G; Timoshenkov, S P

    2002-01-01

    The heavy-current nanosecond generator with the pulse capacity up to 1.6 GW and output voltage of 0.5-1 MW is described. The generator contains four capacity storages, one induction storage and six solid body commutators: one thyristor, four magnetic commutators and a semiconductor current breaker on the SOS-diodes. The results of studies on the energy change-over efficiency through a semiconductor breaker by various external resistance loads as well as the results of the thermal and frequency tests are presented. It is established that selection of the optimal cooling system provides for the generator continuous mode of operation with the pulse sequence frequency from 300 Hz up to 850 Hz

  5. 30 CFR 77.900 - Low- and medium-voltage circuits serving portable or mobile three-phase alternating current...

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Low- and medium-voltage circuits serving... Medium-Voltage Alternating Current Circuits § 77.900 Low- and medium-voltage circuits serving portable or mobile three-phase alternating current equipment; circuit breakers. Low- and medium-voltage...

  6. Anti-rebound Cushion Device for Hydraulic Breaker

    Institute of Scientific and Technical Information of China (English)

    Zhao Hongqiang

    2005-01-01

    This paper analyzes the phenomenon of rebound impact and its negative influence on the present hydraulic breaker. To get over its shortcomings, a new anti-rebound cushion device has been designed to prevent the phenomenon of rebound impact. A hydraulic cushion is used to absorb the rebound impact energy, which can be released for the next stroke of the hydraulic breaker. Thus, there is little loss of energy, and the efficiency of the impact system can be increased by 5 %. The absorption effect of the hydraulic anti-rebound cushion increases the service life of breaker components by up to twice as long as in the current breaker. A dynamic model and a motion equation of the anti-rebound cushion device are presented, and the optimum frequency and damping ratio are obtained, providing optimum design parameters for the anti-rebound cushion device.

  7. The Choice on Circuit Breakerof Small and Medium-sized Hydropower Station Generator%中小型水电站发电机专用断路器的选择

    Institute of Scientific and Technical Information of China (English)

    殷晓安

    2016-01-01

    Correct design of generator circuit breaker is directly related to thereasonable investment of electrical equipment, the operation maintenance,and the safe and economic operation of hydropower station.Medial-sized generators used to choose normal oil circuit breaker or vacuum circuit breaker or SF6 circuit breaker.In recent years,common vacuum breaker is becoming more and more popular.Small and medium-sized hydropower station should choose special generator circuit breaker according to different connection method and different capacity of generator circuit breaker method.%正确设计选择发电机保护断路器直接关系到水电站后期的电气设备合理投资、运行维护及保证水电站长周期安全经济地运行.过去中小型水轮发电机大都选用普通型的油断路器或真空断路器或SF6断路器等,近些年来选用普通真空断路器的越来越多.中小型水电站应根据不同接线方式、不同容量的发电机出口断路方法,选择发电机专用断路器.

  8. LARGE EDDY SIMULATION FOR PLUNGING BREAKER WAVE

    Institute of Scientific and Technical Information of China (English)

    Bai Yu-chuan; Wang Zhao-yin

    2003-01-01

    As wave propagates into shallow water, the shoaling effect leads to increase of wave height, and at a certain position, the wave will be breaking. The breaking wave is powerful agents for generating turbulence, which plays an important role in most of the fluid dynamical processes in the surf zone, so a proper numerical model for describing the turbulent effect is needed urgently. A numerical model is set up to simulate the wave breaking process, which consists of a free surface model using the surface marker method and the vertical two-dimensional model that solves the flow equations. The turbulence is described by Large Eddy Simulation (LES) method where the larger turbulent features are simulated by solving the flow equations, and the small-scale turbulence that is represented by a sub-grid model. A dynamic eddy viscosity sub-grid scale stress model has been used for the present simulation. The large eddy simulation model, which we presented in this paper, can be used to study the propagation of a solitary wave in constant water depth and the shoaling of a non-breaking solitary wave on a beach. To track free-surface movements, The TUMMAC method is employed. By applying the model to wave breaking problem in the surf zone, we found that these model results compared very well with experimental data. In addition, this model is able to reproduce the complicated flow phenomena, especially the plunging breaker.

  9. Fracturing Fluid (Guar Polymer Gel Degradation Study by using Oxidative and Enzyme Breaker

    Directory of Open Access Journals (Sweden)

    Aung Kyaw

    2012-06-01

    Full Text Available Oxidative and enzyme breakers are used in this research project with the main objective to study on the degradation pattern of fracturing fluid (i.e., guar polymer gel as a function of time, temperature and breaker concentration itself. The fracturing fluid used in hydraulic fracturing or frac pack contain a chemical breakers to reduce the viscosity of the fluid intermingled with the proppant. Chemical breakers reduce viscosity of the guar polymer by cleaving the polymer into small-molecular-weight fragments. The reduction of viscosity will facilitate the flow-back of residual polymer providing rapid recovery of polymer from proppant pack. Ineffective breakers or misapplication of breakers can result in screen-outs or flow-back of viscous fluids both of which can significantly decrease the well productivity. Breaker activity of low to medium temperature range oxidative and enzyme breaker systems was evaluated. ViCon NF an oxidative breaker (Halliburton product and GBW 12- CD an enzyme breaker (BJ Services product were used in this research project with the main objective to study on the degradation pattern of fracturing fluid (guar polymer gel as a function of (time, temperature and breaker concentration itself. This study provides focuses on the way to mix the fracturing fluid, compositions of the fracturing fluid and how to conduct the crosslink and break test. Crosslink test indicate the optimum cross-linker concentration to produce good crosslink gel and the break test gave the characteristic of the gel during degradation process and also the break time. Besides relying on the laboratory experiment, information obtained from research on SPE and US Pattern papers were used to make a comparison study on oxidative and enzyme breakers properties. Degradation pattern observed from the break test showed that reduction in gel viscosity depends on time, temperature and breaker concentration. Observations from experiment also revealed that small

  10. Experimental investigation of the inception of a spilling breaker

    Science.gov (United States)

    Liberzon, Dan; Shemer, Lev

    2013-11-01

    Conditions for the inception of a spilling breaker were studied in 18 m long tank. Peregrine breather-type wave train was excited to generate breaker at a desired location. Parameters of the breaker were obtained using wave gages and two synchronized 2 Mega pixel cameras operating at 60 fps. The instantaneous surface elevation in the vicinity of the breaker's crest was measured by 5 wave gages, while the local wave shape and the inception of breaking were identified from 18 Mpixel video records of the contact line shape variation at the side wall of the tank. An additional identical camera looking at the wave field from above was used to measure the velocity field in the vicinity of the breaking location using Particle Tracking Velocimetry (PTV). Floating particles with diameter of about 3 mm were used for that purpose. Both cameras were synchronized. The instantaneous crest location and velocity were determined from surface elevation fluctuations records. Actual local instantaneous crest velocities differ from both the phase and group velocities of the dominant wave and are compared with the instantaneous horizontal water velocities at various stages of waves breaking.

  11. Energy Extraction for the LHC Superconducting Circuits

    CERN Document Server

    Dahlerup-Petersen, K; Schmidt, R; Sonnemann, F

    2001-01-01

    The superconducting magnets of the LHC will be powered in about 1700 electrical circuits. The energy stored in circuits, up to 1.3 GJ, can potentially cause severe damage of magnets, bus bars and current leads. In order to protect the superconducting elements after a resistive transition, the energy is dissipated into a dump resistor installed in series with the magnet chain that is switched into the circuit by opening current breakers. Experiments and simulation studies have been performed to identify the LHC circuits that need energy extraction. The required values of the extraction resistors have been computed. The outcome of the experimental results and the simulation studies are presented and the design of the different energy extraction systems that operate at 600 A and at 13 kA is described.

  12. 粒子群优化的KFCM及SVM诊断模型在断路器故障诊断中的应用%Application of Particle Swarm Fused KFCM and Classification Model of SVM for Fault Diagnosis of Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    梅飞; 梅军; 郑建勇; 张思宇; 朱克东

    2013-01-01

    为了利用相对较少的故障数据样本对断路器主要故障类型进行较为准确的在线判断,提出了一种基于融合粒子群的模糊核聚类(particle swarm fused kernel fuzzy C-means, P-KFCM)与支持向量机(support vector machine,SVM)的故障诊断方法。通过对断路器分合闸电流信号的分析,找出与断路器主要故障类型相对应的特征量;据此对采样信号进行处理,建立故障特征样本空间;利用 P-KFCM 算法对故障训练样本进行预分类,并以此为基础建立多SVM故障预测模型。P-KFCM算法将粒子群(particle swarm optimization,PSO)的全局搜索能力融入KFCM中,有效的解决了局部最优问题,在一定程度上提升了诊断结果的可靠性。实验结果表明,该方法在诊断断路器主要机械故障方面能够取得较好的效果。%To make accurate judgments of circuit breakers’ main fault types in on-line system using relatively small amounts of fault data, a fault diagnostic method was proposed in this paper. This method combined particle swarm fused kernel fuzzy C-means (P-KFCM) and support vector machine (SVM). Through analysis of the opening and closing current signals, characteristic values corresponding to main fault types could be found, based on which we could process sample signals and establish feature space of fault samples. P-KFCM was utilized to pre-classify fault training samples, on the basis of which multi-SVM fault prediction model could be established. At the same time, it integrated global search ability of particle swarm optimization (PSO) into KFCM to solve local optimum, which would effectively improve reliability of diagnostic results. Experiment results have proved that the proposed method achieves perfect results in diagnosing circuit breakers’ main mechanical faults.

  13. Causes Analysis, Treatment and Prevention of Remote Switch Refused Action and Tripping Coil Burnout in 110kV Circuit Breaker%110 kV断路器远控分闸开关拒动跳闸线圈烧毁故障原因分析及处理防范

    Institute of Scientific and Technical Information of China (English)

    毛艳东

    2015-01-01

    Through introducing the refused action in breaking the 110kV 161QF remote switch in Dahua hydropower station as well as theoretically analyzing and investigating the reasons of the refused action and the tripping coil burnout, it is found that there is tripping coil burnout risk in the control circuit due to the design defect of switch op-erating mechanism. To eliminate it, some correction measures are presented and brought into operation after passed through on-site inspection.%通过介绍大化水电厂一起远控分闸110 kV 161QF开关过程中出现分闸失灵、开关拒动故障,综合排查故障原因,对跳闸线圈烧毁原因进行详细分析,并通过理论分析, 最后发现开关操作机构设计上存在的缺陷,因操作机构存在的缺陷导致控制回路存在严重隐患,提出整改防范措施,并通过现场检验后投入运行无问题,排除了跳闸线圈烧毁隐患.

  14. Equivalent Circuit for Half-Bridge MMC Dc Fault Current Contribution

    OpenAIRE

    Leterme, Willem; Beerten, Jef; Van Hertem, Dirk

    2016-01-01

    The modular multilevel converter (MMC) is currently the preferred converter topology for HVDC point-to-point links and the likely choice for future meshed HVDC grids. For breaker dimensioning or protection system design, thorough knowledge of the dc fault currents supplied by these converters is required. In this paper, the dc fault current supplied by the half-bridge MMC is analyzed and an equivalent circuit model is proposed. The proposed equivalent circuit has a low complexity and accurate...

  15. Algebraic circuits

    CERN Document Server

    Lloris Ruiz, Antonio; Parrilla Roure, Luis; García Ríos, Antonio

    2014-01-01

    This book presents a complete and accurate study of algebraic circuits, digital circuits whose performance can be associated with any algebraic structure. The authors distinguish between basic algebraic circuits, such as Linear Feedback Shift Registers (LFSRs) and cellular automata, and algebraic circuits, such as finite fields or Galois fields. The book includes a comprehensive review of representation systems, of arithmetic circuits implementing basic and more complex operations, and of the residue number systems (RNS). It presents a study of basic algebraic circuits such as LFSRs and cellular automata as well as a study of circuits related to Galois fields, including two real cryptographic applications of Galois fields.

  16. Every Speed Breaker Is A Source Of Power

    Directory of Open Access Journals (Sweden)

    N. N. Ghuge,

    2014-03-01

    Full Text Available Electricity in India, is a big problem which is faced by people who reside in the country. Electricity is the form of energy, Electricity is a basic part of nature and it is one of our most widely used forms of energy. We get electricity, which is a secondary energy source, from the conversion of other sources of energy, like coal, natural gas, oil, nuclear power and other natural sources, which are called primary sources. Before electricity generation began slightly over 100 years ago, we use kerosene lamps, and rooms were warmed by wood-burning or coal burning stoves. Direct current (DC electricity had been used in arc lights for outdoor lighting. In the late-1800s, Nikola Tesla pioneered the generation, transmission, and use of alternating current (AC electricity, which can be transmitted over much greater distances than direct current. Generating electricity by speed breakers is innovative and useful concept. R

  17. The Impact of a Deep-Water Plunging Breaker

    CERN Document Server

    Ikeda, Christine; Brucker, Kyle A; Drazen, David A; Dommermuth, Douglas G; Fu, Thomas; Fullerton, Anne M; Duncan, James H

    2014-01-01

    The impact of a plunging breaking wave (wavelength approximately 1.3m) on a rigidly mounted rigid cube structure (dimension 0.31m) that is partially submerged is explored through experiments and numerical calculations. The experiments are carried out in a wave tank and the breaker is generated with a mechanical wave maker using a dispersive focusing technique. The water-surface profile upstream of the front face of the cube and in its vertical centerplane is measured using a cinematic laser-induced fluorescence technique. The three-dimensional flow in the wave tank is simulated directly using the Numerical Flow Analysis (NFA) code. The experiments and the calculations are used to explore the details of the wave-impact process and, in particular, the formation of the high-speed vertical jet that is found on the front face of the cube under some impact conditions.

  18. Transients due to multiple prestrike phenomenon when energizing capacitor banks with a vacuum circuit breaker

    OpenAIRE

    Barbieri, María Beatriz; Bianchi Lastra, Raúl E.; Arnera, Patricia L.; Agüero, Jorge Luis

    2006-01-01

    The phenomenon of multiple prestrikes of the arc was observed in field measurements of the energization of a single 4.8 MVAR, 13.2 kV capacitor bank. This paper presents field measurements records and the results of the computer simulation of the transients when energizing the capacitor bank, made with the objective to calculate the overvoltages generated in remote points. A method to avoid the phenomenon is proposed.

  19. 高压直流断路器技术%Technology of HVDC Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    王帮田

    2010-01-01

    笔者着重从高压直流输电换流站用直流断路器的功能要求、主要性能、基本构成、开断原理及试验技术等方面进行探讨,分析了直流断路器和交流断路器在电流转换、环境耐受和开断性能等方面的区别,给出了直流断路器转换电流的计算公式,表明合理选择直流断路器绝缘件的爬电比距对于提高运行水平非常重要,且开断直流电流必须创造过零点.另外,还阐述了直流断路器与交流断路器有主要区别的性能试验,供中国高压直流断路器的研制者参考.

  20. Peculiarities of the relays intended for operating trip coils of the high-voltage circuit breakers

    Directory of Open Access Journals (Sweden)

    Gurevich Vladimir

    2007-01-01

    Full Text Available Parameters of the subminiature electromagnetic relays used as output elements in microprocessor relay protection, do not correspond to technical specifications on these relay protection. The reasons of this discrepancy are analyzed. Contradictions and discrepancies of the international standards in this area are considered. It is shown, that absence of clearness in standards and mistakes in technical specifications of manufacturers of microprocessor protection do not allow estimating correctly technical parameters and lead to decrease in reliability of relay protection.

  1. General Analysis of Vacuum Circuit Breaker Switching Overvoltages in Offshore Wind Farms

    DEFF Research Database (Denmark)

    Ghafourian, S. M.; Arana, I.; Holbøll, Joachim

    2016-01-01

    Understanding mechanisms of switching transient overvoltages in modern electrical power systems is a necessity to ensure a proper design of power plants and switchgear and the required level of reliable and secure system operation. High fidelity plant modelling and accurate transient analysis...... is a prerequisite for understanding the mechanisms of how overvoltages are created and whether or not the voltage withstand capabilities of system components will be exceeded. This research is focused on switching overvoltages typical for an offshore wind farm power collection grid configuration that comprises...... on the transformer terminal voltage during closing operation was studied. A wind farm power collection system was modelled in ATP-EMTP environment. To validate the results obtained through computer simulation, field measurements from an actual system were used....

  2. Calculation of transport coefficients of air-water vapor mixtures thermal plasmas used in circuit breakers

    Directory of Open Access Journals (Sweden)

    KOHIO Niéssan

    2014-12-01

    Full Text Available In this paper we calculate the transport coefficients of plasmas formed by air and water vapor mixtures. The calculation, which assume local thermodynamic equilibrium (LTE are performed in the temperature range from 500 to 12000 K. We use the Gibbs free energy minimization method to determine the equilibrium composition of the plasmas, which is necessary to calculate the transport coefficients. We use the Chapman-Enskog method to calculate the transport coefficients. The results are presented and discussed according to the rate of water vapor. The results of the total thermal conductivity and electrical conductivity show in particular that the increasing of the rate of water vapor in air can be interesting for power cut. This could be improve the performance of plasma during current breaking in air contaminate by the water vapor.

  3. In-line task 57: Component evaluation. [of circuit breakers, panel switches, etc. for space shuttle

    Science.gov (United States)

    Boykin, J. C.

    1974-01-01

    Design analysis tests were performed on selected power switching components to determine the possible applicability of off-the-shelf hardware to space shuttles. Various characteristics were also evaluated in those devices to determine the most desirable properties for the space shuttle.

  4. A brief talk on the vacuum circuit breaker%浅谈真空断路器

    Institute of Scientific and Technical Information of China (English)

    林立生

    2001-01-01

    @@ 1真空断路器的概况 真空断路器是一种以气体分子极为稀少,分子间的平均自由行程很大,电子与分子相碰撞的机会极少,绝缘强度很高的真空空间为熄弧介质的新型断路器. 我国于20世纪60年代开始研制真空断路器,70年代正式投入生产.目前我国10kV级真空断路器的额定短路开断电流已达63kA,切电容器组的重击穿率已降至1%以下.

  5. Vacuum Circuit Breaker Modelling for the Assessment of Transient Recovery Voltages Under Various Network Configurations

    DEFF Research Database (Denmark)

    Bak, Claus Leth; Borghetti, Alberto; Glasdam, Jakob Bærholm;

    2017-01-01

    for both VCB sizing and insulation coordination studies of the components nearby the switching device. In this respect, their accurate modelling, which is the object of the paper, becomes crucial. In particular, the paper presents (the concept of) a VCB model and two relevant applications showing the model...... capabilities of simulating TRVs due to opening/closing manoeuvres, namely the switching of large electrical motors and the switching of cables collecting offshore wind farms (OWFs). Data from digital fault recorder (DFR) in a water-pumping plant and from a measurement campaign in an OWF using a high......-bandwidth GPS-synchronised measurement system, respectively, are used for model validation. It is shown that the inclusion of detailed VCB models significantly improves the agreement between the measurements related to both pre- and restrikes and the corresponding simulation results obtained by using two well...

  6. Numerical modeling of post current-zero dielectric breakdown in a low voltage circuit breaker

    Science.gov (United States)

    Thenkarai Narayanan, Venkat raman

    Oral delivery of macromolecular therapeutics has remained a challenge. Various factors govern principles of oral absorption, including solubility, tissue permeability, stability and dynamics of the gastrointestinal environment. Developing a macromolecular drug carrier for poorly bioavailable drugs is highly desirable. Dendritic polymers are attractive drug delivery vehicles because of their multifunctional surface groups, globular conformation, branched architecture, low poly dispersity and hydrophilic nature. They also offer traditional benefits of macromolecular systems such as extended plasma residence time and reduced systemic toxicity. Developing a poly(amido amine) (PAMAM) dendrimer-based oral drug delivery vehicle is the long-term goal of this research. PAMAM dendrimers can offer advantages in terms of improving solubility and permeability that can ultimately enhance oral absorption of poorly bioavailable drugs. In this dissertation, first the safety and maximum tolerated dose of six different PAMAM dendrimers was studied after oral and systemic administration. Surface charge of these dendrimers significantly influenced their toxicity profile in vivo with cationic systems proving to be more toxic than anionic systems. The inherent permeability of native anionic dendrimers was then evaluated in a mouse model to assess their potential in oral drug delivery. Results suggested that anionic G6.5 dendrimers exhibited appreciable bioavailability with partial degradation observed under in vivo conditions. Subsequently, camptothecin, a model drug used for the treatment of colorectal carcinoma, was attached to PAMAM dendrimers. Antitumor activity revealed that these conjugates were effective in inhibiting growth of cancer cells in vitro. Preliminary efficacy studies conducted in xenograft tumor models also indicated that dendrimer-drug conjugates have potential for oral chemotherapy. Further detailed in vivo studies are needed to demonstrate the utility of PAMAM-drug conjugates for effective and safe delivery of chemotherapeutics by the oral route.

  7. Large Eddy Simulation for Plunge Breaker and Sediment Suspension

    Institute of Scientific and Technical Information of China (English)

    BAI Yuchuan(白玉川); C.O.NG

    2002-01-01

    Breaking waves are a powerful agent for generating turbulence that plays an important role in many fluid dynamicalprocesses, particularly in the mixing of materials. Breaking waves can dislodge sediment and throw it into suspension,which will then be carried by wave-induced steady current and tidal flow. In order to investigate sediment suspension bybreaking waves, a numerical model based on large-eddy-simulation (LES) is developed. This numerical model can beused to simulate wave breaking and sediment suspension. The model consists of a free-surface model using the surfacemarker method combined with a two-dimensional model that solves the flow equations. The turbulence and the turbulentdiffusion are described by a large-eddy-simulation (LES) method where the large turbulence features are simulated bysolving the flow equations, and a subgrid model represents the small-scale turbulence that is not resolved by the flowmodel. A dynamic eddy viscosity subgrid scale stress model has been used for the present simulation. By applying thismodel to Stokes' wave breaking problem in the surf zone, we find that the model results agree very well with experimentaldata. By use of this model to simulation of the breaking process of a periodic wave, it can be found that the model canreproduce the complicated flow phenomena, especially the plunging breaker. It reflects the dynamic structures of roller orvortex in the plunging breaker, and when the wave breaks, many strong vortex structures will be produced in the innersurf zone where the concentration of suspended sediment can thereby become relatively high.

  8. Definition of the electric requirements for the equipment associated to the limiter reactor on a 550 kV line occurring from manoeuvres under short circuits; Definicao dos requisitos eletricos dos equipamentos associados ao reator limitador em 550 kV, em decorrencia de manobras sob curtos-circuitos

    Energy Technology Data Exchange (ETDEWEB)

    Machado Junior, Camilo; Furuoka, Nita; Rose, Eber Havila [ELETRONORTE, Brasilia, DF (Brazil)]. E-mail: eber@eln.gov.br; Violin, Airton; Martinez, Manuel Luis Barreira [Escola Federal de Engenharia de Itajuba (EFEI), MG (Brazil). Inst. de Engenharia Eletrica. Lab. de Alta Tensao; Saraiva, Carlos Alberto Moura [Consorcio THEMAG-ENGEVIX, Sao Paulo, SP (Brazil)

    2001-07-01

    This paper presents the ascertaining based on the TRT study results performed to the definition of the new circuit breakers characteristics for the second stage of the Tucurui hydroelectric power plant, placed at the northern Brazil and with final configuration of two power houses and two air isolated substations, amounting 9 GVA. To reduce the short-circuit level to satisfactory values series reactors were used among the 550 kV substations. The result of the studies associated to the circuit breaker specifications are presented.

  9. Resonance circuits for adiabatic circuits

    Directory of Open Access Journals (Sweden)

    C. Schlachta

    2003-01-01

    Full Text Available One of the possible techniques to reduces the power consumption in digital CMOS circuits is to slow down the charge transport. This slowdown can be achieved by introducing an inductor in the charging path. Additionally, the inductor can act as an energy storage element, conserving the energy that is normally dissipated during discharging. Together with the parasitic capacitances from the circuit a LCresonant circuit is formed.

  10. Assessment of short circuit level and TRV impact on existing substation due to the new addition of a wind farm

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X.; Zhou, Z.; Wilson, P. [Manitoba HVDC Research Centre, Winnipeg, MB (Canada); Anasco, H. [City of Lethbridge, Lethbridge, AB (Canada)

    2006-07-01

    This paper presented a study and breaker evaluation of a substation in the City of Lethbridge with the addition of a 70.5 MW wind plant. The aim of the study was to assess the ability of the electric equipment to cope with short circuit growth. Another objective of the study was to investigate the interconnected power system around the substation power system and determine if transient recovery voltage (TRV) exceeded breaker breaker ratings. A simulation was conducted using PSCAD/EMTDC to analyze the short current levels increase and TRV waveforms. The short current level, peak values, and rate of rise of the TRV waveforms were determined, and values were compared with breaker ratings by IEC standards. Induction generators at the wind farm were modeled as voltage sources with sub-transient impedance. The sub-transient reactance of the induction machines was calculated. Fifteen test cases were presented. Results of the simulation showed that without the addition of the proposed wind farm, the fault current at the substation was 6.94 kA. With the new wind farm in service, the fault current was 7.01 kA, an 0.07 kA increase. Peak TRV values were in the range of between 25 to 195 kV. The allowable TRV peak value from the manufacturer and IEC standard 62271-100 are 235 to 237 kV. Results suggested that the actual TRV peak values of the 138 kV breakers at the substation are well below the peak TRV capability value. The actual rate of rise of the recovery voltage (RRRV) of the 2 breakers in the substation were in the range of 0.08 to 0.85 kV/{mu}s. It was concluded that the breaker TRV did not exceed the breaker capabilities at the substation. The addition of the wind farm caused no major impacts on the 138 kV breakers at the substation. 5 refs., 2 tabs., 6 figs.

  11. GATING CIRCUITS

    Science.gov (United States)

    Merrill, L.C.

    1958-10-14

    Control circuits for vacuum tubes are described, and a binary counter having an improved trigger circuit is reported. The salient feature of the binary counter is the application of the input signal to the cathode of each of two vacuum tubes through separate capacitors and the connection of each cathode to ground through separate diodes. The control of the binary counter is achieved in this manner without special pulse shaping of the input signal. A further advantage of the circuit is the simplicity and minimum nuruber of components required, making its use particularly desirable in computer machines.

  12. Reprises textuelles dans The Dew Breaker d’Edwidge Danticat Rewriting / Reprising in Edwidge Danticat’s The Dew Breaker

    Directory of Open Access Journals (Sweden)

    Corinne Duboin

    2007-01-01

    Full Text Available In her recent novel, The Dew Breaker (2004, Haitian-American writer Edwidge Danticat weaves together the lives of her bruised Haitian characters and their torturer, a former Tonton Macoute, all in exile in the US. Seven of the nine chapters were previously published as separate short stories and have been rearranged to form a novel. The reader is then led to unravel a narrative tangle made of many threads. The disparate nature of the book, its non-linear narrative, the plurality of stories and voices, the gaps in a fragmented, elliptic text all bear witness to an alternative approach to creative writing. Like a seamstress, the novelist pieces together individual stories, connecting them as the multifarious facets of a great whole. In the wake of francophone Haitian writers (namely Jacques Roumain, the author of Masters of the Dew, and Jacques Stephen Alexis who wrote General Sun, My Brother, Edwidge Danticat fictionalizes the traumatic history of a people confronted with violence and terror and engages in a complex intertextual game. Combining ethics and aesthetics, temporal and textual memory, the novelist explores facts and, rather than giving answers, raises difficult questions. Her characters, whether victims or perpetrators, all strive to free themselves from a haunting past: is it ever possible to forgive so as to heal the pain? Can one make amends for the harm that has been done to victims who seek redress?

  13. Breaker concentrations required to improve the permeability of proppant packs damaged by concentrated linear and borate-crosslinked fracturing fluids

    Energy Technology Data Exchange (ETDEWEB)

    Brannon, H. (BJ Services (United States)); Pulsinelli, R.J. (Dowell Schlumberger, Tulsa, OK (United States))

    1992-11-01

    This paper reports on the concentrations of an oxidative breaker required to reduce significantly the proppant-pack permeability damage caused by aqueous hydraulic fracturing fluids. Long-term, proppant-pack permeability testing was used to evaluate linear and borate-crosslinked gels. Results indicate that increasing the breaker concentration can reduce proppant-pack permeability damage very effectively.

  14. Design and Operation Principles of DC Circuit Breakers - Development of a Solid State DC Breaker for the NTNU/SINTEF Smart Grid and Renewable Energy Laboratory

    OpenAIRE

    Norum, Eivind Ødegaard

    2016-01-01

    Exciting high voltage direct current (HVDC) transmission systems are mainly point-to-point connections. A multi-terminal HVDC grid consisting of three or more inter connected converter stations is suggested in order to increase the reliability, redundancy and flexibility in long distant bulk power transmission. Similar to AC (alternating current) grids, a protection system of HVDC-grids must be able to clear faults without affecting the remaining healthy parts of the grid. Thus, there is a ne...

  15. The effect of bubbles on air-water oxygen transfer in the breaker zone

    Science.gov (United States)

    Kakuno, Shohachi; Moog, Douglas B.; Tatekawa, Tetsuya; Takemura, Kenji; Yamagishi, Tatsuya

    The effect of bubbles entrained in the breaker zone on air-water oxygen transfer is examined. First, the area of bubbles entrained by breakers generated on a sloping bottom in a wave tank is analyzed using a color image sensor which can count the pixel number of a specific color in a frame. It was found that the time-averaged pixel number over a wave period has a strong relationship to the energy dissipation rate per unit mass of the breaker. The time-averaged pixel number is then incorporated with some modification into an equation proposed by Eckenfelder for the calculation of the mass transfer coefficient from bubble surfaces in an aeration tank. The coefficient resulting from the modified equation shows a strong relationship between the mass transfer coefficient and the dissipation rate.

  16. Design of a New Type of Distribution Valve for Hydraulic Breaker and Analysis of Energy Consumption

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Energy consumed by distribution valves causes an energy loss for the output energy of hydraulic breakers, which has a significant influence on its efficiency. A new type of distribution valve used for hydraulic breakers, designed to reduce energy consumption, is analyzed on the basis of the operating principle and energy loss of the current distribution valve. The new distribution valve adopts a cone valve and the optimization technique of unequal open degree for the valve port. Theoretical calculations and analyses have proven that the new distribution valve can reduce energy loss by 9.0127J, or energy consumption by 31%, during an impact cycle and the efficiency of the hydraulic breaker can be raised by 4.5%. It has the following characteristics: little leakage, little pressure loss and low energy consumption.

  17. A study of plunging breaker mechanics by PIV measurements and a Navier-Stokes solver

    DEFF Research Database (Denmark)

    Emarat, Narumon; Forehand, David I. M.; Christensen, Erik Damgaard

    2000-01-01

    The mechanics of a surf-zone plunging breaker are studied from Particle Image Velocimetry (PIV) measurements and a numerical model based on the Navier-Stokes equations, using a Volume of Fluid (VOF) method. An additional numerical model using a Boundary-Integral Method (BIM) is also used in order...... to generate input conditions for the main numerical model. The PIV measurements were performed at the University of Edinburgh and then compared against the results found by the numerical model developed at DHI Water and Environment. Good agreement is found, throughout the breaking process, between...... the velocity fields of the plunging breaker measured using PIV and those predicted by the numerical model....

  18. 基于电弧电压的混合型直流断路器%Hybrid DC Breaker Based on Arc Voltage

    Institute of Scientific and Technical Information of China (English)

    吕玮; 方太勋; 杨浩; 杨兵; 王宇; 石巍

    2015-01-01

    The hybrid direct current(DC) breaker has good static characteristics and good dynamic characteristics.The multi-terminal high-voltage direct current (HVDC) transmission network is largely dependent on the development of DC circuit breaker technology. This paper presents a hybrid DC circuit breaker based on arc voltage, and derives mathematical relationship of current-commutation.Simulating the key part-high speed switch by the electro-magnetic repulsion mechanism is performed using finite element analysis.A 1 kA/1 5 kV hybrid DC breaker is designed based on the above research,and the test results show that the prototype”s arc maximum current-commutation capacity is 3 kA.The process of current transfer from high-speed switch to solid state switch accords with the exponential function,and is consistent with theoretical derivation.The prototype can break the short-circuit current less than 10 kA within 5 ms,and the break time depends primarily on high-speed switch and arc voltage.%混合型直流断路器同时具有传统机械开关良好的静态特性和固态开关无弧快速关断的动态特性,多端直流输电网络很大程度上依赖于直流断路器技术的发展。文中提出了一种基于电弧电压的混合型直流断路器,推导了电流换流物理过程的数学关系。通过有限元分析软件,进行了关键部件———电磁斥力机构高速开关的仿真计算。在以上基础上进行了1 kA/15 kV 直流断路器样机的设计研制,试验结果表明,该样机的电弧最大换流能力为3 kA,电流从高速开关向固态开关转移的过程呈指数关系,与理论推导相符。该样机能够在5 ms 内分断10 kA 短路电流,分断时间主要取决于高速开关开断速度以及电弧电压大小。

  19. Discussion about the Relevant Problems of the Coordination of Two Anti-pumping Circuit%断路器两套防跳回路配合问题探讨

    Institute of Scientific and Technical Information of China (English)

    邱涛; 井雨刚; 杜绍辉

    2012-01-01

    Through analyzing the abnormality of the 220 kV circuit breakers anti-pumping circuit in 220 kV substation of Weihai electric power plant, the coordination between the anti-pumping circuit in circuit breaker itself and the anti- pumping circuit inside control kiosk is described. A parasitic circuit in between circuit breaker and the kiosk is found then solution method to this problem is worked out.%通过对威海电厂220kV升压站220kV断路器防跳回路出现故障现象进行分析,阐述开关本体防跳回路和装置操作箱防跳回路的配合,揭示断路器本体防跳回路与装置操作箱防跳回路之间存在的寄生回路问题,并提出解决技术方案。

  20. Controllable circuit

    DEFF Research Database (Denmark)

    2010-01-01

    A switch-mode power circuit comprises a controllable element and a control unit. The controllable element is configured to control a current in response to a control signal supplied to the controllable element. The control unit is connected to the controllable element and provides the control...

  1. Design and optimization of LCL-VSC grid-tied converter having short circuit fault current limiting ability

    Science.gov (United States)

    Liu, Mengqi; Liu, Haijun; Wang, Zhikai

    2017-01-01

    Traditional LCL grid-tied converters haven't the ability to limit the short-circuit fault current and only remove grid-connected converter using the breaker. However, the VSC converters become uncontrollable after the short circuit fault cutting off and the power switches may be damaged if the circuit breaker removes slowly. Compared to the filter function of the LCL passive components in traditional VSC converters, the novel LCL-VSC converter has the ability of limiting the short circuit fault current using the reasonable designed LCL parameters. In this paper the mathematical model of the LCL converter is established and the characteristics of the short circuit fault current generated by the ac side and dc side are analyzed. Thus one design and optimization scheme of the reasonable LCL passive parameter is proposed for the LCL-VSC converter having short circuit fault current limiting ability. In addition to ensuring the LCL passive components filtering the high-frequency harmonic, this scheme also considers the impedance characteristics to limit the fault current of AC and DC short circuit fault respectively flowing through the power switch no more than the maximum allowable operating current, in order to make the LCL converter working continuously. Finally, the 200kW simulation system is set up to prove the validity and feasibility of the theoretical analysis using the proposed design and optimization scheme.

  2. Affective Circuits

    DEFF Research Database (Denmark)

    to the intersecting streams of goods, people, ideas, and money as they circulate between African migrants and their kin who remain back home. They also show the complex ways that emotions become entangled in these exchanges. Examining how these circuits operate in domains of social life ranging from child fosterage......Moving between Africa and Europe, the book explores the many ways migrants sustain and rework family ties and intimate relationships at home and abroad. It demonstrates how their quotidian efforts—on such a mass scale—contribute to a broader process of social regeneration. The contributors point...

  3. Enhanced rhamnolipids production via efficient foam-control using stop valve as a foam breaker.

    Science.gov (United States)

    Long, Xuwei; Shen, Chong; He, Ni; Zhang, Guoliang; Meng, Qin

    2017-01-01

    In this study, a stop valve was used as a foam breaker for dealing with the massive overflowing foam in rhamnolipid fermentation. As found, a stop valve at its tiny opening could break over 90% of the extremely stable rhamnolipid foam into enriched liquid when foam flows through the sharp gap in valve. The efficient foam-control by the stop valve considerably improved the rhamnolipid fermentation and significantly enhanced the rhamnolipid productivity by 83% compared to the regular fermentation. This efficient foam breaking was mainly achieved by a high shear rate in combination with fast separation of air from the collapsed foam. Altogether, the stop valve possessed a great activity in breaking rhamnolipid foam, and the involving mechanism holds the potential for developing efficient foam breakers for industrial rhamnolipid fermentation.

  4. Study on Low Corrosion Gel Breaker%低腐蚀破胶剂的研究

    Institute of Scientific and Technical Information of China (English)

    陆原; 任奕; 王仲广; 逯学朝; 郭海军; 王铁钢

    2014-01-01

    An compound corrosion inhibitor BHH-DRH1 was developed in order to solve corrosion problem of oxidative gel breaker. It can be show that the inhibitor can decrease effectively corrosion of gel breaker JPC in laboratory test. It was suggested that the content of inhibitor was 1%. The technology was trialed in offshore oilfield, and the trial result reached expected effect.%针对氧化类的破胶剂引起的腐蚀问题,研究开发了一种复合型缓蚀剂BHH-DRH1,通过室内评价认为其很好地抑制了破胶剂JPC的腐蚀,推荐现场加注量为1.0%。该技术在南海某油田进行试用,取得了预期效果。

  5. Lagrangian kinematics of steep waves up to the inception of a spilling breaker

    Science.gov (United States)

    Shemer, Lev; Liberzon, Dan

    2014-01-01

    Horizontal Lagrangian velocities and accelerations at the surface of steep water-waves are studied by Particle Tracking Velocimetry for gradually increasing crest heights up to the inception of a spilling breaker. Localized steep waves are excited using wavemaker-generated Peregrine breather-type wave trains. Actual crest and phase velocities are estimated from video recorded sequences of the instantaneous wave shape as well as from surface elevation measurements by wave gauges. Effects of nonlinearity and spectral width on phase velocity, as well as the relation between phase velocity and crest propagation speed are discussed. The inception of a spilling breaker is associated with the horizontal velocity of water particles at the crest attaining that of the crest, thus confirming the kinematic criterion for inception of breaking.

  6. Lagrangian kinematics of steep waves up to the inception of a spilling breaker

    CERN Document Server

    Shemer, Lev

    2013-01-01

    Horizontal Lagrangian velocities and accelerations at the surface of steep water-waves are studied by Particle Tracking Velocimetry (PTV) for gradually increasing crest heights up to the inception of a spilling breaker. Localized steep waves are excited using wavemaker-generated Peregrine breather-type wave trains. Actual crest and phase velocities are estimated from video recorded sequences of the instantaneous wave shape as well as from surface elevation measurements by wave gauges. Effects of nonlinearity and spectral width on phase velocity, as well as relation between the phase velocity and crest propagation speed are discussed. The inception of a spilling breaker is associated with the horizontal velocity of water particles at the crest attaining that of the crest, thus confirming the kinematic criterion for inception of breaking.

  7. Suppressing breakers with polar oil films: Using an epic sea rescue to model wave energy budgets

    Science.gov (United States)

    Cox, Charles S.; Zhang, Xin; Duda, Timothy F.

    2017-02-01

    Oil has been used to still stormy seas for centuries, but the mechanisms are poorly understood. Here we examine the processes by using quantitative information from a remarkable 1883 sea rescue where oil was used to reduce large breakers during a storm. Modeling of the oil film's extent and waves under the film suggests that large breakers were suppressed by a reduction of wind energy input. Modification of surface roughness by the film is hypothesized to alter the wind profile above the sea and the energy flow. The results are central to understanding air-sea momentum exchange, including its role in such processes as cyclone growth and storm surge, although they address only one aspect of the complex problem of wind interaction with the ocean surface.

  8. Detusking fence-breaker elephants as an approach in human-elephant conflict mitigation.

    Directory of Open Access Journals (Sweden)

    Matthew Mutinda

    Full Text Available Human-elephant conflict (HEC is a recurring problem that appears wherever the range of elephants and humans overlap. Different methods including the use of electric fences are used worldwide to mitigate this conflict. Nonetheless, elephants learn quickly that their tusks do not conduct electricity and use them to break down fences (fence-breakers.In Lewa Wildlife Conservancy, Kenya, destructive elephants (Loxodonta africana were monitored between 2010 and 2013. The fence-breaking rate reached four incidents (fence-breaking per elephant per 100 days. Ten bull males and 57 females were identified as fence-breakers. The bulls were involved in 85.07% and the females in 14.93% of incidents. The Kenya Wildlife Service approved detusking (partial cutting of tusks in four of the 10 fence-breakers as a way of preventing them from breaking down fences, thereby mitigating HEC in the Conservancy. The result of the detusking was a drastic six-fold reduction in damage to fences (range: 1.67 to 14.5 times less fence-breaking by the four worst fence-breaker elephants, because with trimmed tusks elephants lack the tools to break down fences. Detusking could not totally eliminate fence destruction because, despite lacking their tools, elephants can still destroy fences using their heads, bodies and trunks, albeit less effectively. On the other hand, apart from inherent aesthetic considerations, the detusking of elephants may have certain negative effects on factors such as elephants' social hierarchies, breeding, mate selection and their access to essential minerals and food.Elephant detusking seems to be effective in drastically reducing fence-breaking incidents, nonetheless its negative effects on behaviour, access to food and its aesthetical consequences still need to be further studied and investigated.

  9. Collective of mechatronics circuit

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1987-02-15

    This book is composed of three parts, which deals with mechatronics system about sensor, circuit and motor. The contents of the first part are photo sensor of collector for output, locating detection circuit with photo interrupts, photo sensor circuit with CdS cell and lamp, interface circuit with logic and LED and temperature sensor circuit. The second part deals with oscillation circuit with crystal, C-R oscillation circuit, F-V converter, timer circuit, stability power circuit, DC amp and DC-DC converter. The last part is comprised of bridge server circuit, deformation bridge server, controlling circuit of DC motor, controlling circuit with IC for PLL and driver circuit of stepping motor and driver circuit of Brushless.

  10. Analog circuit design designing dynamic circuit response

    CERN Document Server

    Feucht, Dennis

    2010-01-01

    This second volume, Designing Dynamic Circuit Response builds upon the first volume Designing Amplifier Circuits by extending coverage to include reactances and their time- and frequency-related behavioral consequences.

  11. Analog circuit design designing waveform processing circuits

    CERN Document Server

    Feucht, Dennis

    2010-01-01

    The fourth volume in the set Designing Waveform-Processing Circuits builds on the previous 3 volumes and presents a variety of analog non-amplifier circuits, including voltage references, current sources, filters, hysteresis switches and oscilloscope trigger and sweep circuitry, function generation, absolute-value circuits, and peak detectors.

  12. Design of a fast linear drive for (hybrid) circuit breakers: development and validation of a multi domain simulation environment

    NARCIS (Netherlands)

    Roodenburg, B.; Evenblij, B.H.

    2008-01-01

    The force acting on a current carrying body, which is induced by magnetic fields gained more interest due to new applications. These magnetic techniques are used for decades to accelerate or move objects, for instance for catheter navigation in the human body, metal forming or for fast opening of el

  13. The Effect of Current-Limiting Reactors on the Tripping of Short Circuits in High-Voltage Electrical Equipment

    Energy Technology Data Exchange (ETDEWEB)

    Volkov, M. S.; Gusev, Yu. P., E-mail: GusevYP@mpei.ru; Monakov, Yu. V.; Cho, Gvan Chun [National Research University “Moscow Power Engineering Institute,” (Russian Federation)

    2016-01-15

    The insertion of current-limiting reactors into electrical equipment operating at a voltage of 110 and 220 kV produces a change in the parameters of the transient recovery voltages at the contacts of the circuit breakers for disconnecting short circuits, which could be the reason for the increase in the duration of the short circuit, damage to the electrical equipment and losses in the power system. The results of mathematical modeling of the transients, caused by tripping of the short circuit in a reactive electric power transmission line are presented, and data are given on the negative effect of a current-limiting resistor on the rate of increase and peak value of the transient recovery voltages. Methods of ensuring the standard requirements imposed on the parameters of the transient recovery voltages when using current-limiting reactors in the high-voltage electrical equipment of power plants and substations are proposed and analyzed.

  14. A novel advanced glycation endproducts breaker restores cardiovascular dysfunctions in experimental diabetic rats

    Institute of Scientific and Technical Information of China (English)

    GangCHENG; Li-liWANG; Hong-yingLIU; HaoCUI; Ying-linCAO; SongLI

    2005-01-01

    AIM The formation of advanced glycation endproducts (AGEs) on connective tissue and matrix components leads to increases in collagen crosslinkingthat contributes to aortic and myocardial stiffness in normal aging and which occurs at an accelerated rate in diabetes. In this study, we examined the effects of a novel AGEs breaker, C36, on cardiovascular dysfunctions in experimental diabetic rats. METHODS and RESULTS Male Wiatar rats were made diabetic by i.p. injection of 70mg/kg streptozotocin. After 12 weeks of diabetes, the animals were randomly divided into 4 groups (n=8-11),

  15. GAS AND OIL POWER DISTRIBUTION RATIO OF A NEW HYDRAULIC BREAKER

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hongqiang; LI Meixiang; GAO Bin; HE Qinghua

    2007-01-01

    The working principle of a new hydraulic breaker operated jointly by gas and hydraulic flow which has a reasonable structure, high efficiency and long piston life-span, is analyzed, and the optimal power distribution ratio of the sealed nitrogen gas to the high-pressure oil in the process of piston impacting is studied. Through theoretical analysis, optimization simulation and detailed calculation, it is determined that the impact system has optimal mechanical performance and highest efficiency when the distribution ratio Φis between 0.3 and 0.5. The theoretical result is also verified by repeated tests.

  16. Experimental and numerical investigation of the internal kinetics of a surf-zone plunging breaker

    DEFF Research Database (Denmark)

    Emarat, Narumon; Forehand, David I.M.; Christensen, Erik Damgaard

    2012-01-01

    for surfzone breaking waves have been reported. In this study, a comparison is made between the experimental and numerical investigation of the internal kinematics of a surf-zone plunging breaker. The full-field velocity measuring technique known as Particle Image Velocimetry (PIV) is used in the experiments...... that this was due to the small amount of smoothing applied in the BIM to enable it to continue to supply input data to the Navier–Stokes solver well beyond the breaking of the wave. In addition, some small differences were also found between the numerically predicted velocity distributions and those measured...

  17. Solid-state circuits

    CERN Document Server

    Pridham, G J

    2013-01-01

    Solid-State Circuits provides an introduction to the theory and practice underlying solid-state circuits, laying particular emphasis on field effect transistors and integrated circuits. Topics range from construction and characteristics of semiconductor devices to rectification and power supplies, low-frequency amplifiers, sine- and square-wave oscillators, and high-frequency effects and circuits. Black-box equivalent circuits of bipolar transistors, physical equivalent circuits of bipolar transistors, and equivalent circuits of field effect transistors are also covered. This volume is divided

  18. Simple Autonomous Chaotic Circuits

    Science.gov (United States)

    Piper, Jessica; Sprott, J.

    2010-03-01

    Over the last several decades, numerous electronic circuits exhibiting chaos have been proposed. Non-autonomous circuits with as few as two components have been developed. However, the operation of such circuits relies on the non-ideal behavior of the devices used, and therefore the circuit equations can be quite complex. In this paper, we present two simple autonomous chaotic circuits using only opamps and linear passive components. The circuits each use one opamp as a comparator, to provide a signum nonlinearity. The chaotic behavior is robust, and independent of nonlinearities in the passive components. Moreover, the circuit equations are among the algebraically simplest chaotic systems yet constructed.

  19. Circuit analysis for dummies

    CERN Document Server

    Santiago, John

    2013-01-01

    Circuits overloaded from electric circuit analysis? Many universities require that students pursuing a degree in electrical or computer engineering take an Electric Circuit Analysis course to determine who will ""make the cut"" and continue in the degree program. Circuit Analysis For Dummies will help these students to better understand electric circuit analysis by presenting the information in an effective and straightforward manner. Circuit Analysis For Dummies gives you clear-cut information about the topics covered in an electric circuit analysis courses to help

  20. Solenoid-Simulation Circuit

    Science.gov (United States)

    Simon, R. A.

    1986-01-01

    Electrical properties of solenoids imitated for tests of control circuits. Simulation circuit imitates voltage and current responses of two engine-controlling solenoids. Used in tests of programs of digital engine-control circuits, also provides electronic interface with circuits imitating electrical properties of pressure sensors and linear variable-differential transformers. Produces voltages, currents, delays, and discrete turnon and turnoff signals representing operation of solenoid in engine-control relay. Many such circuits used simulating overall engine circuitry.

  1. 基于PAC&GPRS的高压直流开关振荡回落参数在线监测系统%On-line monitoring system of HVDC breaker based on PAC and GPRS

    Institute of Scientific and Technical Information of China (English)

    金涛; 蔡超; 王俊; 阮玲

    2013-01-01

    针对传统的离线式高压直流开关监测方法的诸多不足,为了能够实时地掌握直流开关的振荡回路的工作状态,在线计算出高压直流开关的状态参数,提出一种基于PAC(Programmable Automation Controller)和GPRS(General Packet Radio Service)的高压直流开关的在线监测方法.该方法通过采用霍尔传感器将振荡回路的振荡电流信号线性转换为电压信号,再通过PAC高数采样模块采集该电压信号,将采集到的振荡信号在本地存储之后再通过GPRS无线传输技术将采集到的数据传回后台数据处理中心,后台数据处理中心在线处理分析数据,得出RLC的参数值.实验室和葛洲坝换流站的实验表明,该系统对电力系统运行无任何影响,同时该系统能够准确地、高精度地采集振荡信号,正确地计算出振荡回路RLC参数,为准确获取高压直流开关的工作状态提供有利基础.%In order to get the real-time operating state of the oscillation circuit of the high voltage direct circuit (HVDC) breaker,and calculate the RLC parameters of the oscillation circuit,an on-line monitoring system of HVDC breaker's oscillation circuit is put forward based on the programmable automation controller (PAC) data acquisition technique.The hardware and software are designed to achieve this goal.In this system,a Hall sensor is used to linearly transform the oscillation current into voltage signal; then the voltage is gathered by PAC data acquisition system; after stored on local disk of PAC,the data is transmitted to the data processing center.After these,the RLC parameters of the oscillation circuit could be calculated automatically.With this on-line monitoring system of DC breaker's oscillation circuit,we have done experiments in our laboratory and in Gezhouba convertor station.The experimental data prove that this system does not have any impact on the electric power system; the most important is that it can accurately acquire

  2. Cross-shore redistribution of nourished sand near a breaker bar

    DEFF Research Database (Denmark)

    Jacobsen, Niels Gjøl; Fredsøe, Jørgen

    2014-01-01

    This paper focuses on the optimal location for dumping nourished sand on a barred coastline. This is done by investigating the short-term behavior of the cross-shore redistribution of nourished sediment on a breaker-bar profile in a two-dimensional vertical plane. This is achieved by the use of a...... bar can have both destructive and protective impacts on the original shoreward-located cross-shore profile.......This paper focuses on the optimal location for dumping nourished sand on a barred coastline. This is done by investigating the short-term behavior of the cross-shore redistribution of nourished sediment on a breaker-bar profile in a two-dimensional vertical plane. This is achieved by the use...... over the profile is consider as a means of imposing the net recirculation resulting from longshore nonuniformities or the impact of wind-induced shear stresses. The impact of wave height, irregularity in incident waves, and the size of the sediment grains on the cross-shore distribution of suspended...

  3. Hidden circuits and argumentation

    Science.gov (United States)

    Leinonen, Risto; Kesonen, Mikko H. P.; Hirvonen, Pekka E.

    2016-11-01

    Despite the relevance of DC circuits in everyday life and schools, they have been shown to cause numerous learning difficulties at various school levels. In the course of this article, we present a flexible method for teaching DC circuits at lower secondary level. The method is labelled as hidden circuits, and the essential idea underlying hidden circuits is in hiding the actual wiring of DC circuits, but to make their behaviour evident for pupils. Pupils are expected to find out the wiring of the circuit which should enhance their learning of DC circuits. We present two possible ways to utilise hidden circuits in a classroom. First, they can be used to test and enhance pupils’ conceptual understanding when pupils are expected to find out which one of the offered circuit diagram options corresponds to the actual circuit shown. This method aims to get pupils to evaluate the circuits holistically rather than locally, and as a part of that aim this method highlights any learning difficulties of pupils. Second, hidden circuits can be used to enhance pupils’ argumentation skills with the aid of argumentation sheet that illustrates the main elements of an argument. Based on the findings from our co-operating teachers and our own experiences, hidden circuits offer a flexible and motivating way to supplement teaching of DC circuits.

  4. 550 kV双断口交流滤波器断路器暂态恢复电压仿真%Simulation of Transient Recovery Voltage of 550 kV AC Filter Breaker with Double Breaks

    Institute of Scientific and Technical Information of China (English)

    施健; 罗兵; 傅明利; 厉天威; 曾向君; 贾磊; 张福增

    2016-01-01

    直流换流站安装有不同滤波次数的交流滤波器(AC filter,ACF),ACF断路器频繁操作以满足换流站无功补偿的需要,在开断大容性电流后断口承受交直流混合电压的共同作用,断口直流分压按电阻分布,而断口等效电阻受外界环境的影响,因此断口承受的电压可能会超过其绝缘能力。以国内典型的550 kV瓷柱式双断口小组滤波器断路器为例,利用PSCAD建立暂态恢复电压(TRV)仿真电路模型,对影响断口TRV分布的环境因素进行了仿真,仿真结果显示外界环境因素(如湿度、污秽、干湿不均等)对断口TRV影响较大,在特定环境条件下当断口绝缘电阻下降较大且两断口电阻值差异较大时,断口最大TRV值会接近或超过规范要求值,从而可能造成断口电弧重燃或闪络故障。%AC filters (ACFs)for different harmonics are installed in HVDC stations,they switch on and off very often with circuit breakers for reactive power compensation. ACF breakers bear transient recovery voltages (TRV)comprising AC and DC voltages after switching off large capacitive current,because the DC voltage component is decided and divided by resistance which is influenced by the ambient environment of porcelain breaker external insulation,the TRV may exceed the insulation requirement. Using a typical 550 kV AC filter procelain breaker with two breaks used in HVDC stations as an example,a simulation model of TRV is established based on PSCAD to simulate the influencing factors of TRV. The simulation results show that the ambient environment,such as humidity, dirt and dry zone,can seriously affect the TRV of breaks. With specific ambient environment conditions,when the break resistance decreases and the diffence between the two break resistances is large,the maximum break TRV may approach or even exceed the theshhold value,which will result in breaker restrike or flashover.

  5. The circuit designer's companion

    CERN Document Server

    Williams, Tim

    2013-01-01

    The Circuit Designer's Companion covers the theoretical aspects and practices in analogue and digital circuit design. Electronic circuit design involves designing a circuit that will fulfill its specified function and designing the same circuit so that every production model of it will fulfill its specified function, and no other undesired and unspecified function.This book is composed of nine chapters and starts with a review of the concept of grounding, wiring, and printed circuits. The subsequent chapters deal with the passive and active components of circuitry design. These topics are foll

  6. Intuitive analog circuit design

    CERN Document Server

    Thompson, Marc

    2013-01-01

    Intuitive Analog Circuit Design outlines ways of thinking about analog circuits and systems that let you develop a feel for what a good, working analog circuit design should be. This book reflects author Marc Thompson's 30 years of experience designing analog and power electronics circuits and teaching graduate-level analog circuit design, and is the ideal reference for anyone who needs a straightforward introduction to the subject. In this book, Dr. Thompson describes intuitive and ""back-of-the-envelope"" techniques for designing and analyzing analog circuits, including transistor amplifi

  7. Electrical Circuits and Water Analogies

    Science.gov (United States)

    Smith, Frederick A.; Wilson, Jerry D.

    1974-01-01

    Briefly describes water analogies for electrical circuits and presents plans for the construction of apparatus to demonstrate these analogies. Demonstrations include series circuits, parallel circuits, and capacitors. (GS)

  8. Circuits on Cylinders

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Arnsfelt; Miltersen, Peter Bro; Vinay, V

    2006-01-01

    We consider the computational power of constant width polynomial size cylindrical circuits and nondeterministic branching programs. We show that every function computed by a Pi2 o MOD o AC0 circuit can also be computed by a constant width polynomial size cylindrical nondeterministic branching...... program (or cylindrical circuit) and that every function computed by a constant width polynomial size cylindrical circuit belongs to ACC0....

  9. Electric circuits essentials

    CERN Document Server

    REA, Editors of

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Electric Circuits I includes units, notation, resistive circuits, experimental laws, transient circuits, network theorems, techniques of circuit analysis, sinusoidal analysis, polyph

  10. Load testing circuit

    DEFF Research Database (Denmark)

    2009-01-01

    A load testing circuit a circuit tests the load impedance of a load connected to an amplifier. The load impedance includes a first terminal and a second terminal, the load testing circuit comprising a signal generator providing a test signal of a defined bandwidth to the first terminal of the load...

  11. Short-circuit logic

    NARCIS (Netherlands)

    Bergstra, J.A.; Ponse, A.

    2010-01-01

    Short-circuit evaluation denotes the semantics of propositional connectives in which the second argument is only evaluated if the first argument does not suffice to determine the value of the expression. In programming, short-circuit evaluation is widely used. A short-circuit logic is a variant of p

  12. Piezoelectric drive circuit

    Science.gov (United States)

    Treu, Jr., Charles A.

    1999-08-31

    A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes.

  13. Signal sampling circuit

    NARCIS (Netherlands)

    Louwsma, Simon Minze; Vertregt, Maarten

    2011-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital converte

  14. Signal sampling circuit

    NARCIS (Netherlands)

    Louwsma, Simon Minze; Vertregt, Maarten

    2010-01-01

    A sampling circuit for sampling a signal is disclosed. The sampling circuit comprises a plurality of sampling channels adapted to sample the signal in time-multiplexed fashion, each sampling channel comprising a respective track-and-hold circuit connected to a respective analogue to digital converte

  15. Lightning Surge Analysis in 154 kV S/S due to Flashover on the 4 Circuits Tower

    Energy Technology Data Exchange (ETDEWEB)

    Woo, J. W.; Shim, E. B.; Kwak, J. S.; Choi, B. J. [Korea Electric Power Corporation (Korea)

    2000-07-01

    This paper describes the analysis results for the protection of lightning surge at 154 kV substation. We found that the surge arrester is needed at the inlet structure. The maximum overvoltage is about 1,500 kV at the circuit breaker without the surge arrester at the inlet structure. This value can be lower than 600 kV by installing the surge arrester at the inlet structure. In addition to the shield wire should be considered to prevent the shielding failure by the direct lightning stroke. (author). 6 refs., 8 figs.

  16. Integral Battery Power Limiting Circuit for Intrinsically Safe Applications

    Science.gov (United States)

    Burns, Bradley M.; Blalock, Norman N.

    2010-01-01

    A circuit topology has been designed to guarantee the output of intrinsically safe power for the operation of electrical devices in a hazardous environment. This design uses a MOSFET (metal oxide semiconductor field-effect transistor) as a switch to connect and disconnect power to a load. A test current is provided through a separate path to the load for monitoring by a comparator against a preset threshold level. The circuit is configured so that the test current will detect a fault in the load and open the switch before the main current can respond. The main current passes through the switch and then an inductor. When a fault occurs in the load, the current through the inductor cannot change immediately, but the voltage drops immediately to safe levels. The comparator detects this drop and opens the switch before the current in the inductor has a chance to respond. This circuit protects both the current and voltage from exceeding safe levels. Typically, this type of protection is accomplished by a fuse or a circuit breaker, but in order for a fuse or a circuit breaker to blow or trip, the current must exceed the safe levels momentarily, which may be just enough time to ignite anything in a hazardous environment. To prevent this from happening, a fuse is typically current-limited by the addition of the resistor to keep the current within safe levels while the fuse reacts. The use of a resistor is acceptable for non-battery applications where the wasted energy and voltage drop across the resistor can be tolerated. The use of the switch and inductor minimizes the wasted energy. For example, a circuit runs from a 3.6-V battery that must be current-limited to 200 mA. If the circuit normally draws 10 mA, then an 18-ohm resistor would drop 180 mV during normal operation, while a typical switch (0.02 ohm) and inductor (0.97 ohm) would only drop 9.9 mV. From a power standpoint, the current-limiting resistor protection circuit wastes about 18 times more power than the

  17. Record breakers

    CERN Multimedia

    Antonella Del Rosso

    2012-01-01

    In the sixties, CERN’s Fellows were but a handful of about 50 young experimentalists present on site to complete their training. Today, their number has increased to a record-breaking 500. They come from many different fields and are spread across CERN’s different activity areas.   “Diversifying the Fellowship programme has been the key theme in recent years,” comments James Purvis, Head of the Recruitment, Programmes and Monitoring group in the HR Department. “In particular, the 2005 five-yearly review introduced the notion of ‘senior’ and ‘junior’ Fellowships, broadening the target audience to include those with Bachelor-level qualifications.” Diversification made CERN’s Fellowship programme attractive to a wider audience but the number of Fellows on site could not have increased so much without the support of EU-funded projects, which were instrumental in the growth of the programme. ...

  18. Formation and development of a breaker bar under regular waves. Part 2: Sediment transport and morphology

    DEFF Research Database (Denmark)

    Jacobsen, Niels Gjøl; Fredsøe, Jørgen

    2014-01-01

    In Part 2 of this work, the hydrodynamic model described in Part 1 is applied for the simulation of sediment transport and the associated morphological development of breaker bars. The sediment description is split into bed load and suspended load, and like the hydrodynamics the sediment transport...... is phase-resolved in order to get on- and offshore directed contributions to the sediment transport from phase lags between the suspended sediment and the hydrodynamics.First, the sediment transport over a morphologically fixed bed of a constant slope is considered, and the transport rates are discussed......) is discussed relative to the reference simulation.The coupling between sediment transport rate and morphology is analysed and discussed. © 2014 Elsevier B.V....

  19. Antibiotic resistance breakers: can repurposed drugs fill the antibiotic discovery void?

    Science.gov (United States)

    Brown, David

    2015-12-01

    Concern over antibiotic resistance is growing, and new classes of antibiotics, particularly against Gram-negative bacteria, are needed. However, even if the scientific hurdles can be overcome, it could take decades for sufficient numbers of such antibiotics to become available. As an interim solution, antibiotic resistance could be 'broken' by co-administering appropriate non-antibiotic drugs with failing antibiotics. Several marketed drugs that do not currently have antibacterial indications can either directly kill bacteria, reduce the antibiotic minimum inhibitory concentration when used in combination with existing antibiotics and/or modulate host defence through effects on host innate immunity, in particular by altering inflammation and autophagy. This article discusses how such 'antibiotic resistance breakers' could contribute to reducing the antibiotic resistance problem, and analyses a priority list of candidates for further investigation.

  20. Reversible Logic Circuit Synthesis

    CERN Document Server

    Shende, V V; Markov, I L; Prasad, A K; Hayes, John P.; Markov, Igor L.; Prasad, Aditya K.; Shende, Vivek V.

    2002-01-01

    Reversible, or information-lossless, circuits have applications in digital signal processing, communication, computer graphics and cryptography. They are also a fundamental requirement for quantum computation. We investigate the synthesis of reversible circuits that employ a minimum number of gates and contain no redundant input-output line-pairs (temporary storage channels). We propose new constructions for reversible circuits composed of NOT, Controlled-NOT, and TOFFOLI gates (the CNT gate library) based on permutation theory. A new algorithm is given to synthesize optimal reversible circuits using an arbitrary gate library. We also describe much faster heuristic algorithms. We also pursue applications of the proposed techniques to the synthesis of quantum circuits.

  1. Scaled photographs of surf over the full range of breaker sizes on the north shore of Oahu and Jaws, Maui, Hawaiian Islands (NODC Accession 0001753)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Digital surf photographs were scaled using surfers as height benchmarks to estimate the size of the breakers. Historical databases for surf height in Hawaii are...

  2. Feedback in analog circuits

    CERN Document Server

    Ochoa, Agustin

    2016-01-01

    This book describes a consistent and direct methodology to the analysis and design of analog circuits with particular application to circuits containing feedback. The analysis and design of circuits containing feedback is generally presented by either following a series of examples where each circuit is simplified through the use of insight or experience (someone else’s), or a complete nodal-matrix analysis generating lots of algebra. Neither of these approaches leads to gaining insight into the design process easily. The author develops a systematic approach to circuit analysis, the Driving Point Impedance and Signal Flow Graphs (DPI/SFG) method that does not require a-priori insight to the circuit being considered and results in factored analysis supporting the design function. This approach enables designers to account fully for loading and the bi-directional nature of elements both in the feedback path and in the amplifier itself, properties many times assumed negligible and ignored. Feedback circuits a...

  3. Exact Threshold Circuits

    DEFF Research Database (Denmark)

    Hansen, Kristoffer Arnsfelt; Podolskii, Vladimir V.

    2010-01-01

    We initiate a systematic study of constant depth Boolean circuits built using exact threshold gates. We consider both unweighted and weighted exact threshold gates and introduce corresponding circuit classes. We next show that this gives a hierarchy of classes that seamlessly interleave with the ......We initiate a systematic study of constant depth Boolean circuits built using exact threshold gates. We consider both unweighted and weighted exact threshold gates and introduce corresponding circuit classes. We next show that this gives a hierarchy of classes that seamlessly interleave...... with the well-studied corresponding hierarchies defined using ordinary threshold gates. A major open problem in Boolean circuit complexity is to provide an explicit super-polynomial lower bound for depth two threshold circuits. We identify the class of depth two exact threshold circuits as a natural subclass...

  4. Analog circuit design

    CERN Document Server

    Dobkin, Bob

    2012-01-01

    Analog circuit and system design today is more essential than ever before. With the growth of digital systems, wireless communications, complex industrial and automotive systems, designers are being challenged to develop sophisticated analog solutions. This comprehensive source book of circuit design solutions aids engineers with elegant and practical design techniques that focus on common analog challenges. The book's in-depth application examples provide insight into circuit design and application solutions that you can apply in today's demanding designs. <

  5. Parallelizing quantum circuit synthesis

    OpenAIRE

    Di Matteo, Olivia; Mosca, Michele

    2016-01-01

    Quantum circuit synthesis is the process in which an arbitrary unitary operation is decomposed into a sequence of gates from a universal set, typically one which a quantum computer can implement both efficiently and fault-tolerantly. As physical implementations of quantum computers improve, the need is growing for tools which can effectively synthesize components of the circuits and algorithms they will run. Existing algorithms for exact, multi-qubit circuit synthesis scale exponentially in t...

  6. Regenerative feedback resonant circuit

    Science.gov (United States)

    Jones, A. Mark; Kelly, James F.; McCloy, John S.; McMakin, Douglas L.

    2014-09-02

    A regenerative feedback resonant circuit for measuring a transient response in a loop is disclosed. The circuit includes an amplifier for generating a signal in the loop. The circuit further includes a resonator having a resonant cavity and a material located within the cavity. The signal sent into the resonator produces a resonant frequency. A variation of the resonant frequency due to perturbations in electromagnetic properties of the material is measured.

  7. Analog circuits cookbook

    CERN Document Server

    Hickman, Ian

    2013-01-01

    Analog Circuits Cookbook presents articles about advanced circuit techniques, components and concepts, useful IC for analog signal processing in the audio range, direct digital synthesis, and ingenious video op-amp. The book also includes articles about amplitude measurements on RF signals, linear optical imager, power supplies and devices, and RF circuits and techniques. Professionals and students of electrical engineering will find the book informative and useful.

  8. Timergenerator circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Timer/Generator Circuits Manual is an 11-chapter text that deals mainly with waveform generator techniques and circuits. Each chapter starts with an explanation of the basic principles of its subject followed by a wide range of practical circuit designs. This work presents a total of over 300 practical circuits, diagrams, and tables.Chapter 1 outlines the basic principles and the different types of generator. Chapters 2 to 9 deal with a specific type of waveform generator, including sine, square, triangular, sawtooth, and special waveform generators pulse. These chapters also include pulse gen

  9. CMOS circuits manual

    CERN Document Server

    Marston, R M

    1995-01-01

    CMOS Circuits Manual is a user's guide for CMOS. The book emphasizes the practical aspects of CMOS and provides circuits, tables, and graphs to further relate the fundamentals with the applications. The text first discusses the basic principles and characteristics of the CMOS devices. The succeeding chapters detail the types of CMOS IC, including simple inverter, gate and logic ICs and circuits, and complex counters and decoders. The last chapter presents a miscellaneous collection of two dozen useful CMOS circuits. The book will be useful to researchers and professionals who employ CMOS circu

  10. Electronic devices and circuits

    CERN Document Server

    Pridham, Gordon John

    1968-01-01

    Electronic Devices and Circuits, Volume 1 deals with the design and applications of electronic devices and circuits such as passive components, diodes, triodes and transistors, rectification and power supplies, amplifying circuits, electronic instruments, and oscillators. These topics are supported with introductory network theory and physics. This volume is comprised of nine chapters and begins by explaining the operation of resistive, inductive, and capacitive elements in direct and alternating current circuits. The theory for some of the expressions quoted in later chapters is presented. Th

  11. Circuits and filters handbook

    CERN Document Server

    Chen, Wai-Kai

    2003-01-01

    A bestseller in its first edition, The Circuits and Filters Handbook has been thoroughly updated to provide the most current, most comprehensive information available in both the classical and emerging fields of circuits and filters, both analog and digital. This edition contains 29 new chapters, with significant additions in the areas of computer-aided design, circuit simulation, VLSI circuits, design automation, and active and digital filters. It will undoubtedly take its place as the engineer's first choice in looking for solutions to problems encountered in the design, analysis, and behavi

  12. MOS integrated circuit design

    CERN Document Server

    Wolfendale, E

    2013-01-01

    MOS Integral Circuit Design aims to help in the design of integrated circuits, especially large-scale ones, using MOS Technology through teaching of techniques, practical applications, and examples. The book covers topics such as design equation and process parameters; MOS static and dynamic circuits; logic design techniques, system partitioning, and layout techniques. Also featured are computer aids such as logic simulation and mask layout, as well as examples on simple MOS design. The text is recommended for electrical engineers who would like to know how to use MOS for integral circuit desi

  13. Security electronics circuits manual

    CERN Document Server

    MARSTON, R M

    1998-01-01

    Security Electronics Circuits Manual is an invaluable guide for engineers and technicians in the security industry. It will also prove to be a useful guide for students and experimenters, as well as providing experienced amateurs and DIY enthusiasts with numerous ideas to protect their homes, businesses and properties.As with all Ray Marston's Circuits Manuals, the style is easy-to-read and non-mathematical, with the emphasis firmly on practical applications, circuits and design ideas. The ICs and other devices used in the practical circuits are modestly priced and readily available ty

  14. Synchronizing Hyperchaotic Circuits

    DEFF Research Database (Denmark)

    Tamasevicius, Arunas; Cenys, Antanas; Namajunas, Audrius;

    1997-01-01

    Regarding possible applications to secure communications the technique of synchronizing hyperchaotic circuits with a single dynamical variable is discussed. Several specific examples including the fourth-order circuits with two positive Lyapunov exponents as well as the oscillator with a delay line...

  15. A Virtual Circuits Lab

    Science.gov (United States)

    Vick, Matthew E.

    2010-01-01

    The University of Colorado's Physics Education Technology (PhET) website offers free, high-quality simulations of many physics experiments that can be used in the classroom. The Circuit Construction Kit, for example, allows students to safely and constructively play with circuit components while learning the mathematics behind many circuit…

  16. Genetic circuit design automation.

    Science.gov (United States)

    Nielsen, Alec A K; Der, Bryan S; Shin, Jonghyeon; Vaidyanathan, Prashant; Paralanov, Vanya; Strychalski, Elizabeth A; Ross, David; Densmore, Douglas; Voigt, Christopher A

    2016-04-01

    Computation can be performed in living cells by DNA-encoded circuits that process sensory information and control biological functions. Their construction is time-intensive, requiring manual part assembly and balancing of regulator expression. We describe a design environment, Cello, in which a user writes Verilog code that is automatically transformed into a DNA sequence. Algorithms build a circuit diagram, assign and connect gates, and simulate performance. Reliable circuit design requires the insulation of gates from genetic context, so that they function identically when used in different circuits. We used Cello to design 60 circuits forEscherichia coli(880,000 base pairs of DNA), for which each DNA sequence was built as predicted by the software with no additional tuning. Of these, 45 circuits performed correctly in every output state (up to 10 regulators and 55 parts), and across all circuits 92% of the output states functioned as predicted. Design automation simplifies the incorporation of genetic circuits into biotechnology projects that require decision-making, control, sensing, or spatial organization.

  17. Low voltage switchgear breaker loss of pressure from the research and application of switch device%低压开关柜断路器失压自投装置的研究与应用

    Institute of Scientific and Technical Information of China (English)

    陈柳

    2013-01-01

    in view of the distribution network area of low voltage circuit breaker can vote, after pressure loss due to delay in sending, de-veloped a low- voltage circuit breaker based on time relay since loss of pressure switch device, the device delay through closing loop, avoid trans-former excitation inrush current, protection of power grid company and the user's device. Clever use of time relay sliding contact, after a set time delay sliding contact short after connect disconnected, analog manual switch button. Safe, reliable, economic, and greatly shortens the courts to re-cover their jurisdiction for sending time, reduces the customer outage time, reduce the work intensity of the operators, improve the customer satis-faction with the degree of power supply reliability.%针对配网台区低压断路器失压后不能自投,造成延误送电的情况,研发了一种基于时间继电器的低压断路器失压自投装置,该装置延时接通合闸回路,躲过变压器励磁涌流,保护电网公司与用户的设备。巧妙利用时间继电器的滑动触点,经过设定时间后,延时滑动触点短时接通后断开,模拟人工合闸按钮按下。该装置安全、可靠、经济,大大缩短了所辖台区恢复送电所用时间,减少了客户停电时间,减轻了运行人员的工作强度,提高了客户对于供电可靠性的满意程度。

  18. Approximate circuits for increased reliability

    Energy Technology Data Exchange (ETDEWEB)

    Hamlet, Jason R.; Mayo, Jackson R.

    2015-12-22

    Embodiments of the invention describe a Boolean circuit having a voter circuit and a plurality of approximate circuits each based, at least in part, on a reference circuit. The approximate circuits are each to generate one or more output signals based on values of received input signals. The voter circuit is to receive the one or more output signals generated by each of the approximate circuits, and is to output one or more signals corresponding to a majority value of the received signals. At least some of the approximate circuits are to generate an output value different than the reference circuit for one or more input signal values; however, for each possible input signal value, the majority values of the one or more output signals generated by the approximate circuits and received by the voter circuit correspond to output signal result values of the reference circuit.

  19. Approximate circuits for increased reliability

    Energy Technology Data Exchange (ETDEWEB)

    Hamlet, Jason R.; Mayo, Jackson R.

    2015-08-18

    Embodiments of the invention describe a Boolean circuit having a voter circuit and a plurality of approximate circuits each based, at least in part, on a reference circuit. The approximate circuits are each to generate one or more output signals based on values of received input signals. The voter circuit is to receive the one or more output signals generated by each of the approximate circuits, and is to output one or more signals corresponding to a majority value of the received signals. At least some of the approximate circuits are to generate an output value different than the reference circuit for one or more input signal values; however, for each possible input signal value, the majority values of the one or more output signals generated by the approximate circuits and received by the voter circuit correspond to output signal result values of the reference circuit.

  20. Troubleshooting analog circuits

    CERN Document Server

    Pease, Robert A

    1991-01-01

    Troubleshooting Analog Circuits is a guidebook for solving product or process related problems in analog circuits. The book also provides advice in selecting equipment, preventing problems, and general tips. The coverage of the book includes the philosophy of troubleshooting; the modes of failure of various components; and preventive measures. The text also deals with the active components of analog circuits, including diodes and rectifiers, optically coupled devices, solar cells, and batteries. The book will be of great use to both students and practitioners of electronics engineering. Other

  1. Modern TTL circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Modern TTL Circuits Manual provides an introduction to the basic principles of Transistor-Transistor Logic (TTL). This book outlines the major features of the 74 series of integrated circuits (ICs) and introduces the various sub-groups of the TTL family.Organized into seven chapters, this book begins with an overview of the basics of digital ICs. This text then examines the symbology and mathematics of digital logic. Other chapters consider a variety of topics, including waveform generator circuitry, clocked flip-flop and counter circuits, special counter/dividers, registers, data latches, com

  2. Plasmonic Nanoguides and Circuits

    CERN Document Server

    Bozhevolnyi, Sergey

    2008-01-01

    Modern communication systems dealing with huge amounts of data at ever increasing speed try to utilize the best aspects of electronic and optical circuits. Electronic circuits are tiny but their operation speed is limited, whereas optical circuits are extremely fast but their sizes are limited by diffraction. Waveguide components utilizing surface plasmon (SP) modes were found to combine the huge optical bandwidth and compactness of electronics, and plasmonics thereby began to be considered as the next chip-scale technology. In this book, the authors concentrate on the SP waveguide configurati

  3. Pragmatic circuits frequency domain

    CERN Document Server

    Eccles, William

    2006-01-01

    Pragmatic Circuits: Frequency Domain goes through the Laplace transform to get from the time domain to topics that include the s-plane, Bode diagrams, and the sinusoidal steady state. This second of three volumes ends with a-c power, which, although it is just a special case of the sinusoidal steady state, is an important topic with unique techniques and terminology. Pragmatic Circuits: Frequency Domain is focused on the frequency domain. In other words, time will no longer be the independent variable in our analysis. The two other volumes in the Pragmatic Circuits series include titles on DC

  4. Optoelectronics circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Optoelectronics Circuits Manual covers the basic principles and characteristics of the best known types of optoelectronic devices, as well as the practical applications of many of these optoelectronic devices. The book describes LED display circuits and LED dot- and bar-graph circuits and discusses the applications of seven-segment displays, light-sensitive devices, optocouplers, and a variety of brightness control techniques. The text also tackles infrared light-beam alarms and multichannel remote control systems. The book provides practical user information and circuitry and illustrations.

  5. Circuit analysis with Multisim

    CERN Document Server

    Baez-Lopez, David

    2011-01-01

    This book is concerned with circuit simulation using National Instruments Multisim. It focuses on the use and comprehension of the working techniques for electrical and electronic circuit simulation. The first chapters are devoted to basic circuit analysis.It starts by describing in detail how to perform a DC analysis using only resistors and independent and controlled sources. Then, it introduces capacitors and inductors to make a transient analysis. In the case of transient analysis, it is possible to have an initial condition either in the capacitor voltage or in the inductor current, or bo

  6. Monolithic microwave integrated circuits

    Science.gov (United States)

    Pucel, R. A.

    Monolithic microwave integrated circuits (MMICs), a new microwave technology which is expected to exert a profound influence on microwave circuit designs for future military systems as well as for the commercial and consumer markets, is discussed. The book contains an historical discussion followed by a comprehensive review presenting the current status in the field. The general topics of the volume are: design considerations, materials and processing considerations, monolithic circuit applications, and CAD, measurement, and packaging techniques. All phases of MMIC technology are covered, from design to testing.

  7. AGE-breakers cleave model compounds, but do not break Maillard crosslinks in skin and tail collagen from diabetic rats.

    Science.gov (United States)

    Yang, Shengzu; Litchfield, John E; Baynes, John W

    2003-04-01

    Advanced glycation end products (AGE), formed by nonenzymatic Maillard reactions between carbohydrate and protein, contribute to the increase in chemical modification and crosslinking of tissue proteins with age. Acceleration of AGE formation in collagen during hyperglycemia, with resultant effects on vascular elasticity and basement membrane permeability, is implicated in the pathogenesis of diabetic complications. AGE-breakers, such as N-phenacylthiazolium (PTB) and N-phenacyl-4,5-dimethylthiazolium (PMT) halides, have been proposed as therapeutic agents for reversing the increase in protein crosslinking in aging and diabetes. We have confirmed that these compounds, as well as the AGE-inhibitor pyridoxamine (PM), cleave the model AGE crosslink, phenylpropanedione, and have studied the effects of these compounds in reversing the increased crosslinking of skin and tail collagen isolated from diabetic rats. Crosslinking of skin collagen, measured as the half-time for solubilization of collagen by pepsin in 0.5M acetic acid, was increased approximately 5-fold in diabetic, compared to nondiabetic rats. Crosslinking of tail tendon collagen, measured as insolubility in 0.05 N acetic acid, was increased approximately 10-fold. Collagen preparations were incubated in the presence or absence of AGE-breakers or PM in phosphate buffer, pH 7.4, for 24h at 37 degrees C. These treatments did not decrease the half-time for solubilization of diabetic skin collagen by pepsin or increase the acid solubility of diabetic tail tendon collagen. We conclude that, although AGE-breakers and PM cleave model crosslinks, they do not significantly cleave AGE crosslinks formed in vivo in skin collagen of diabetic rats.

  8. C16, a novel advanced glycation endproduct breaker, restores cardiovascular dysfunction in experimental diabetic rats

    Institute of Scientific and Technical Information of China (English)

    Gang CHENG; Li-li WANG; Wen-sheng QU; Long LONG; Hao CUI; Hong-ying LIU; Ying-lin CAO; Song LI

    2005-01-01

    Aim: Advanced glycation endproducts (AGE) have been implicated in the pathogenesis of diabetic complications, including diabetic cardiovascular dysfunction.3-[2-(4-Bromo-phenyl)- 1-methyl-2-oxo-ethyl]-4,5,6,7-tetrahydro-benzothiazol-3-ium bromide (C16), a novel AGE breaker, was investigated for its effects on the development of cardiovascular disease in diabetic rats. Methods: Rats that had streptozotocin-induced diabetes for 12 weeks were divided into groups receiving C16 or vehicle by gavage. Results: In hemodynamic studies of the left ventricle,C16 treatment (25 or 50 mg/kg) for 4 weeks resulted in a significant increase in left ventricular systolic pressure, +dp/dtmax, and -dp/dtmax as compared with vehicletreated diabetic rats. Furthermore, in hemodynamic studies of the cardiovascular system, C16 (12.5, 25, or 50 mg/kg) treatment for 4 weeks resulted in a dosedependent and significant increase in cardiac output, a reduction of total peripheral resistance, and an increase in systemic arterial compliance when compared with vehicle-treated diabetic rats. Biochemical studies showed that C16 treatment also resulted in a significant decrease in immunoglobulin G-red blood cell surface crosslink content and an increase in collagen solubility. Morphological and immunohistochemical examinations indicated that C 16 was able to prevent increases of the collagen type Ⅲ/Ⅰ ratio in the aorta and decrease the accumulation of AGE in the aorta. Conclusion: C16 has the ability to reduce AGE accumulation in tissues in vivo, and can restore diabetes-associated cardiovascular disorders in rats. This provides a potential therapeutic approach for cardiovascular disease associated with diabetes and aging in humans.

  9. Chelation: a fundamental mechanism of action of AGE inhibitors, AGE breakers, and other inhibitors of diabetes complications.

    Science.gov (United States)

    Nagai, Ryoji; Murray, David B; Metz, Thomas O; Baynes, John W

    2012-03-01

    This article outlines evidence that advanced glycation end product (AGE) inhibitors and breakers act primarily as chelators, inhibiting metal-catalyzed oxidation reactions that catalyze AGE formation. We then present evidence that chelation is the most likely mechanism by which ACE inhibitors, angiotensin receptor blockers, and aldose reductase inhibitors inhibit AGE formation in diabetes. Finally, we note several recent studies demonstrating therapeutic benefits of chelators for diabetic cardiovascular and renal disease. We conclude that chronic, low-dose chelation therapy deserves serious consideration as a clinical tool for prevention and treatment of diabetes complications.

  10. Analysis of a Short-Circuit Accident for Low-Voltage Integrated Distribution Box%一起低压综合配电箱短路事故的分析

    Institute of Scientific and Technical Information of China (English)

    朱遵义; 王瑞

    2014-01-01

    Aiming at a short-circuit accident happened during low-voltage integrated distribution box running, this paper analyzed the ac-cident theoretically and carried out calculation and onsite examine, ifnding that when the process chipping, the shift of circuit breakers run-ning shaking caused the short-circuit accident. Because there was non anti-arc board installed between copper bars of inlet wire end of circuit breakers, the accident enlarged. This paper proposed some preventive measures from the aspects of production manufacturing, examine be-fore installation, insulation testing after installation etc.%针对一起低压综合配电箱投入运行时发生的短路事故,对该事故进行了理论分析、计算和现场验证,发现是因加工切屑在断路器投运震动时移位造成短路事故,且由于未在断路器的进线端铜排之间安装隔弧板从而导致事故扩大,并从生产制造、安装前检查、安装后须进行绝缘测试等方面提出了预防措施。

  11. Circuit simulation: some humbling thoughts

    Energy Technology Data Exchange (ETDEWEB)

    Wendt, Manfred; /Fermilab

    2006-01-01

    A short, very personal note on circuit simulation is presented. It does neither include theoretical background on circuit simulation, nor offers an overview of available software, but just gives some general remarks for a discussion on circuit simulator needs in context to the design and development of accelerator beam instrumentation circuits and systems.

  12. Diagnosis technique for the detection of mechanical faults in power breakers; Tecnica de diagnostico para la deteccion de fallas mecanicas en interruptores de potencia

    Energy Technology Data Exchange (ETDEWEB)

    Linan, Roberto; Perez, Marciano; Estrada, J. Manuel [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1996-12-31

    This article reports a non-invasive diagnosis technique for the detection of mechanical faults in power breakers, supporting it with the recording and analysis of vibration signals of the equipment under test. Also, an assessment of four breakers using this technique is presented. [Espanol] En el presente articulo se reporta una tecnica de diagnostico no invasiva para detectar fallas mecanicas en interruptores de potencia, apoyandose en el registro y analisis de senales de vibracion del equipo bajo prueba. Asimismo, se presenta la evaluacion de cuatro interruptores usando esta tecnica.

  13. A semiconductor laser excitation circuit

    Energy Technology Data Exchange (ETDEWEB)

    Kaadzunari, O.; Masaty, K.

    1984-03-27

    A semiconductor laser excitation circuit is patented that is designed for operation in a pulsed mode with a high pulse repetition frequency. This circuit includes, in addition to a semiconductor laser, a high speed photodetector, a reference voltage source, a comparator, and a pulse oscillator and modulator. If the circuit is built using standard silicon integrated circuits, its speed amounts to several hundred megahertz, if it is constructed using gallium arsenide integrated circuits, its speed is several gigahertz.

  14. The Mind Grows Circuits

    CERN Document Server

    Panigrahy, Rina

    2012-01-01

    There is a vast supply of prior art that study models for mental processes. Some studies in psychology and philosophy approach it from an inner perspective in terms of experiences and percepts. Others such as neurobiology or connectionist-machines approach it externally by viewing the mind as complex circuit of neurons where each neuron is a primitive binary circuit. In this paper, we also model the mind as a place where a circuit grows, starting as a collection of primitive components at birth and then builds up incrementally in a bottom up fashion. A new node is formed by a simple composition of prior nodes when we undergo a repeated experience that can be described by that composition. Unlike neural networks, however, these circuits take "concepts" or "percepts" as inputs and outputs. Thus the growing circuits can be likened to a growing collection of lambda expressions that are built on top of one another in an attempt to compress the sensory input as a heuristic to bound its Kolmogorov Complexity.

  15. Chaotic memristive circuit: equivalent circuit realization and dynamical analysis

    Institute of Scientific and Technical Information of China (English)

    Bao Bo-Cheng; Xu Jian-Ping; Zhou Guo-Hua; Ma Zheng-Hua; Zou Ling

    2011-01-01

    In this paper,a practical equivalent circuit of an active flux-controlled memristor characterized by smooth piecewise-quadratic nonlinearity is designed and an experimental chaotic memristive circuit is implemented.The chaotic memristive circuit has an equilibrium set and its stability is dependent on the initial state of the memristor.The initial state-dependent and the circuit parameter-dependent dynamics of the chaotic memristive circuit are investigated via phase portraits,bifurcation diagrams and Lyapunov exponents.Both experimental and simulation results validate the proposed equivalent circuit realization of the active flux-controlled memristor.

  16. Chelation: A Fundamental Mechanism of Action of AGE Inhibitors, AGE Breakers, and Other Inhibitors of Diabetes Complications

    Energy Technology Data Exchange (ETDEWEB)

    Nagai, Rhoji; Murray, David B.; Metz, Thomas O.; Baynes, John

    2012-03-01

    Advanced glycation or glycoxidation end-products (AGE) increase in tissue proteins with age, and their rate of accumulation is increased in diabetes, nephropathy and inflammatory diseases. AGE inhibitors include a range of compounds that are proposed to act by trapping carbonyl and dicarbonyl intermediates in AGE formation. However, some among the newer generation of AGE inhibitors lack reactive functional groups that would trap reaction intermediates, indicating an alternative mechanism of action. We propose that AGE inhibitors function primarily as chelators, inhibiting metal-catalyzed oxidation reactions. The AGE-inhibitory activity of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers is also consistent with their chelating activity. Finally, compounds described as AGE breakers, or their hydrolysis products, also have strong chelating activity, suggesting that these compounds also act through their chelating activity. We conclude that chelation is the common, and perhaps the primary, mechanism of action of AGE inhibitors and breakers, and that chronic, mild chelation therapy should prove useful in treatment of diabetes and age-related diseases characterized by oxidative stress, inflammation and increased chemical modification of tissue proteins by advanced glycoxidation and lipoxidation end-products.

  17. Primer printed circuit boards

    CERN Document Server

    Argyle, Andrew

    2009-01-01

    Step-by-step instructions for making your own PCBs at home. Making your own printed circuit board (PCB) might seem a daunting task, but once you master the steps, it's easy to attain professional-looking results. Printed circuit boards, which connect chips and other components, are what make almost all modern electronic devices possible. PCBs are made from sheets of fiberglass clad with copper, usually in multiplelayers. Cut a computer motherboard in two, for instance, and you'll often see five or more differently patterned layers. Making boards at home is relatively easy

  18. Current Conveyor Equivalent Circuits

    Directory of Open Access Journals (Sweden)

    Tejmal S. Rathore

    2012-02-01

    Full Text Available An equivalence between a class of (current conveyor CC II+ and CC II- circuits is established. CC IIequivalent circuit uses one extra element. However, under certain condition, the extra element can be eliminated. As an illustration of the application of this equivalence, minimal first and second order all-pass filters are derived. Incertain cases, it is possible to compensate the effect of the input resistor of CC at port X. At the end, an open problem of realizing an Nth order (N > 2 minimal all-pass filter is stated.

  19. Inrush Current Control Circuit

    Science.gov (United States)

    Cole, Steven W. (Inventor)

    2002-01-01

    An inrush current control circuit having an input terminal connected to a DC power supply and an output terminal connected to a load capacitor limits the inrush current that charges up the load capacitor during power up of a system. When the DC power supply applies a DC voltage to the input terminal, the inrush current control circuit produces a voltage ramp at the load capacitor instead of an abrupt DC voltage. The voltage ramp results in a constant low level current to charge up the load capacitor, greatly reducing the current drain on the DC power supply.

  20. Circuit design for reliability

    CERN Document Server

    Cao, Yu; Wirth, Gilson

    2015-01-01

    This book presents physical understanding, modeling and simulation, on-chip characterization, layout solutions, and design techniques that are effective to enhance the reliability of various circuit units.  The authors provide readers with techniques for state of the art and future technologies, ranging from technology modeling, fault detection and analysis, circuit hardening, and reliability management. Provides comprehensive review on various reliability mechanisms at sub-45nm nodes; Describes practical modeling and characterization techniques for reliability; Includes thorough presentation of robust design techniques for major VLSI design units; Promotes physical understanding with first-principle simulations.

  1. Electronic circuits fundamentals & applications

    CERN Document Server

    Tooley, Mike

    2015-01-01

    Electronics explained in one volume, using both theoretical and practical applications.New chapter on Raspberry PiCompanion website contains free electronic tools to aid learning for students and a question bank for lecturersPractical investigations and questions within each chapter help reinforce learning Mike Tooley provides all the information required to get to grips with the fundamentals of electronics, detailing the underpinning knowledge necessary to appreciate the operation of a wide range of electronic circuits, including amplifiers, logic circuits, power supplies and oscillators. The

  2. ESD analog circuits and design

    CERN Document Server

    Voldman, Steven H

    2014-01-01

    A comprehensive and in-depth review of analog circuit layout, schematic architecture, device, power network and ESD design This book will provide a balanced overview of analog circuit design layout, analog circuit schematic development, architecture of chips, and ESD design.  It will start at an introductory level and will bring the reader right up to the state-of-the-art. Two critical design aspects for analog and power integrated circuits are combined. The first design aspect covers analog circuit design techniques to achieve the desired circuit performance. The second and main aspect pres

  3. Quantum secure circuit evaluation

    Institute of Scientific and Technical Information of China (English)

    CHEN Huanhuan; LI Bin; ZHUANG Zhenquan

    2004-01-01

    In order to solve the problem of classical secure circuit evaluation, this paper proposes a quantum approach. In this approach, the method of inserting redundant entangled particles and quantum signature has been employed to strengthen the security of the system. Theoretical analysis shows that our solution is secure against classical and quantum attacks.

  4. Superconducting Quantum Circuits

    NARCIS (Netherlands)

    Majer, J.B.

    2002-01-01

    This thesis describes a number of experiments with superconducting cir- cuits containing small Josephson junctions. The circuits are made out of aluminum islands which are interconnected with a very thin insulating alu- minum oxide layer. The connections form a Josephson junction. The current trough

  5. Bioluminescent bioreporter integrated circuit

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, Michael L. (Knoxville, TN); Sayler, Gary S. (Blaine, TN); Paulus, Michael J. (Knoxville, TN)

    2000-01-01

    Disclosed are monolithic bioelectronic devices comprising a bioreporter and an OASIC. These bioluminescent bioreporter integrated circuit are useful in detecting substances such as pollutants, explosives, and heavy-metals residing in inhospitable areas such as groundwater, industrial process vessels, and battlefields. Also disclosed are methods and apparatus for environmental pollutant detection, oil exploration, drug discovery, industrial process control, and hazardous chemical monitoring.

  6. Electronic circuits and systems: A compilation. [including integrated circuits, logic circuits, varactor diode circuits, low pass filters, and optical equipment circuits

    Science.gov (United States)

    1975-01-01

    Technological information is presented electronic circuits and systems which have potential utility outside the aerospace community. Topics discussed include circuit components such as filters, converters, and integrators, circuits designed for use with specific equipment or systems, and circuits designed primarily for use with optical equipment or displays.

  7. Behavioral synthesis of asynchronous circuits

    DEFF Research Database (Denmark)

    Nielsen, Sune Fallgaard

    2005-01-01

    This thesis presents a method for behavioral synthesis of asynchronous circuits, which aims at providing a synthesis flow which uses and tranfers methods from synchronous circuits to asynchronous circuits. We move the synchronous behavioral synthesis abstraction into the asynchronous handshake...... is idle. This reduces unnecessary switching activity in the individual functional units and therefore the energy consumption of the entire circuit. A collection of behavioral synthesis algorithms have been developed allowing the designer to perform time and power constrained design space exploration...

  8. The LMT circuit and SPICE

    DEFF Research Database (Denmark)

    Lindberg, Erik; Murali, K.; Tamacevicius, Arunas

    2006-01-01

    The state equations of the LMT circuit are modeled as a dedicated analogue computer circuit and solved by means of PSpice. The nonlinear part of the system is studied. Problems with the PSpice program are presented.......The state equations of the LMT circuit are modeled as a dedicated analogue computer circuit and solved by means of PSpice. The nonlinear part of the system is studied. Problems with the PSpice program are presented....

  9. Diode, transistor & fet circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Diode, Transistor and FET Circuits Manual is a handbook of circuits based on discrete semiconductor components such as diodes, transistors, and FETS. The book also includes diagrams and practical circuits. The book describes basic and special diode characteristics, heat wave-rectifier circuits, transformers, filter capacitors, and rectifier ratings. The text also presents practical applications of associated devices, for example, zeners, varicaps, photodiodes, or LEDs, as well as it describes bipolar transistor characteristics. The transistor can be used in three basic amplifier configuration

  10. Statistical circuit design for yield improvement in CMOS circuits

    Science.gov (United States)

    Kamath, H. J.; Purviance, J. E.; Whitaker, S. R.

    1990-01-01

    This paper addresses the statistical design of CMOS integrated circuits for improved parametric yield. The work uses the Monte Carlo technique of circuit simulation to obtain an unbiased estimation of the yield. A simple graphical analysis tool, the yield factor histogram, is presented. The yield factor histograms are generated by a new computer program called SPICENTER. Using the yield factor histograms, the most sensitive circuit parameters are noted, and their nominal values are changed to improve the yield. Two basic CMOS example circuits, one analog and one digital, are chosen and their designs are 'centered' to illustrate the use of the yield factor histograms for statistical circuit design.

  11. Circuit Bodging: Atari Punk Console

    NARCIS (Netherlands)

    Allen, B.

    2009-01-01

    Circuit bodging is back! Maxwell is proud to present small, simple, but ultimately lovable little circuits to build for your own, personal pleasure. In this edition we are featuring: The Atari Punk Console. The Atari Punk Console (or APC) is a 555 timer IC based noise maker circuit. The original was

  12. Selective Manipulation of Neural Circuits.

    Science.gov (United States)

    Park, Hong Geun; Carmel, Jason B

    2016-04-01

    Unraveling the complex network of neural circuits that form the nervous system demands tools that can manipulate specific circuits. The recent evolution of genetic tools to target neural circuits allows an unprecedented precision in elucidating their function. Here we describe two general approaches for achieving circuit specificity. The first uses the genetic identity of a cell, such as a transcription factor unique to a circuit, to drive expression of a molecule that can manipulate cell function. The second uses the spatial connectivity of a circuit to achieve specificity: one genetic element is introduced at the origin of a circuit and the other at its termination. When the two genetic elements combine within a neuron, they can alter its function. These two general approaches can be combined to allow manipulation of neurons with a specific genetic identity by introducing a regulatory gene into the origin or termination of the circuit. We consider the advantages and disadvantages of both these general approaches with regard to specificity and efficacy of the manipulations. We also review the genetic techniques that allow gain- and loss-of-function within specific neural circuits. These approaches introduce light-sensitive channels (optogenetic) or drug sensitive channels (chemogenetic) into neurons that form specific circuits. We compare these tools with others developed for circuit-specific manipulation and describe the advantages of each. Finally, we discuss how these tools might be applied for identification of the neural circuits that mediate behavior and for repair of neural connections.

  13. 75 FR 12793 - Petitions for Modification

    Science.gov (United States)

    2010-03-17

    ...); (4) all circuit breakers used to protect trailing cables exceeding the pump approval length or Table... circuit current. The trip setting of these circuit breakers will be sealed or locked, and these circuit breakers will have permanent, legible labels. Each label will identify the circuit breaker as...

  14. 75 FR 34486 - Petitions for Modification

    Science.gov (United States)

    2010-06-17

    ... circuit breakers used to protect trailing cables exceeding the pump approval length or Table 9 of 30 CFR...-circuit current. The trip setting of these circuit breakers will be sealed or locked, and these circuit breakers will have permanent, legible labels. Each label will identify the circuit breaker as...

  15. Neuromorphic silicon neuron circuits

    Directory of Open Access Journals (Sweden)

    Giacomo eIndiveri

    2011-05-01

    Full Text Available Hardware implementations of spiking neurons can be extremely useful for a large variety of applications, ranging from high-speed modeling of large-scale neural systems to real-time behaving systems, to bidirectional brain-machine interfaces. The specific circuit solutions used to implement silicon neurons depend on the application requirements. In this paper we describe the most common building blocks and techniques used to implement these circuits, and present an overview of a wide range of neuromorphic silicon neurons, which implement different computational models, ranging from biophysically realistic and conductance based Hodgkin-Huxley models to bi-dimensional generalized adaptive Integrate and Fire models. We compare the different design methodologies used for each silicon neuron design described, and demonstrate their features with experimental results, measured from a wide range of fabricated VLSI chips.

  16. LC-Circuit Calorimetry

    CERN Document Server

    Bossen, Olaf

    2011-01-01

    We present a new type of calorimeter in which we couple an unknown heat capacity with the aid of Peltier elements to an electrical circuit. The use of an electrical inductance and an amplifier in the circuit allows us to achieve autonomous oscillations, and the measurement of the corresponding resonance frequency makes it possible to accurately measure the heat capacity with an intrinsic statistical error that decreases as ~t^{-3/2} with measuring time t, as opposed to a corresponding error ~t^{-1/2} in the conventional alternating current (a.c.) method to measure heat capacities. We have built a demonstration experiment to show the feasibility of the new technique, and we have tested it on a gadolinium sample at its transition to the ferromagnetic state.

  17. Preconditioner Circuit Analysis

    Science.gov (United States)

    2011-09-01

    ground plane and both operational amplifier terminals. The parasitic capacitances are labeled Cp1 and Cp2 in Figure 19. Figure 19. Circuit for...3.69 MHz 3.98pF 55720 5107 OV                                  (17) Cp2 = 1 pF R1 = 5107 Ω R3...circuit. The capacitor would be placed in parallel with RF to cancel the effect of Cp2 and then feedback factor will look purely resistive. Another

  18. Inkjet deposited circuit components

    Science.gov (United States)

    Bidoki, S. M.; Nouri, J.; Heidari, A. A.

    2010-05-01

    All-printed electronics as a means of achieving ultra-low-cost electronic circuits has attracted great interest in recent years. Inkjet printing is one of the most promising techniques by which the circuit components can be ultimately drawn (i.e. printed) onto the substrate in one step. Here, the inkjet printing technique was used to chemically deposit silver nanoparticles (10-200 nm) simply by ejection of silver nitrate and reducing solutions onto different substrates such as paper, PET plastic film and textile fabrics. The silver patterns were tested for their functionality to work as circuit components like conductor, resistor, capacitor and inductor. Different levels of conductivity were achieved simply by changing the printing sequence, inks ratio and concentration. The highest level of conductivity achieved by an office thermal inkjet printer (300 dpi) was 5.54 × 105 S m-1 on paper. Inkjet deposited capacitors could exhibit a capacitance of more than 1.5 nF (parallel plate 45 × 45 mm2) and induction coils displayed an inductance of around 400 µH (planar coil 10 cm in diameter). Comparison of electronic performance of inkjet deposited components to the performance of conventionally etched items makes the technique highly promising for fabricating different printed electronic devices.

  19. Digital integrated circuits

    Science.gov (United States)

    Polasek, P.; Halamik, J.

    1984-05-01

    The term semicustom designed integrated circuits denotes integrated circuits of an all purpose character in which the production of chips is completed by using one to three custom design stencil type exposure masks. This involves in most cases interconnecting masks that are used to devise the circuit function desired by the customer. Silicon plates with an all purpose gate matrix are produced up to the interconnection level and can be kept at this phase in storage, after which a customer's specific demands can be met very expediently. All purpose logic fields containing 200 logic gates on a chip and an all purpose chip to be expanded to 1,000 logic gates are discussed. The technology facilitates the devising of fast gates with a delay of approximately 5 ns and power dissipation of 1 mW. In assembly it will be possible to make use of the entire assortment of the currently used casings with 16, 18, 20, 24, 28 and 40 outlets. In addition to the development of the mentioned technology, a general methodology for design of the mentioned gate fields is currently under way.

  20. Review on Mechanical Fault Diagnosis of High-voltage Circuit Breakers%高压断路器机械故障诊断技术

    Institute of Scientific and Technical Information of China (English)

    杨景刚; 刘媛; 高山; 陈曦

    2016-01-01

    高压断路器安全可靠运行具有十分重要的工程意义.文中在调研高压断路器常见机械故障类型的基础上,探讨了不同故障产生的原因.评述了目前国内外高压断路器机械故障诊断技术,从机械故障特征量的提取以及故障识别的角度,对其进行了深入的分析.最后综合高压断路器机械故障诊断技术发展现状,指出了目前机械故障诊断急需解决的问题及其发展方向.

  1. 强制过零型高压直流断路器拓扑优化%Topology Optimization of HVDC Circuit Breaker with Forced Current Zero

    Institute of Scientific and Technical Information of China (English)

    方帅; 袁召; 喻新林; 邵敏; 赵文婷; 何俊佳; 潘垣

    2015-01-01

    强制过零型直流断路器作为机械式高压直流断路器的主要研究方向,技术简单成熟,动作可靠性高.笔者基于实际直流电网,对直流断路器可能遇到的最严重故障即直流线路整流侧出口短路故障进行了仿真分析,并提出现有强制过零型直流断路器拓扑的两点缺陷.在此分析基础上,提出了在换流电容两端加装避雷器、在平波电抗器两端加装吸能组件的拓扑优化策略,能有效降低换流电容电压峰值和机械开关断口电压峰值.

  2. 新型高压直流断路器开断能力的研究%Investigation of Interrupting Capability on the New HVDC Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    董溪坤; 王维庆; 张新燕; 付广振

    2013-01-01

    通过对典型高压直流断路器在开断大大直流时开断能力不足的问题的分析,在其电路拓扑的基础之上,引进了一个电阻元件,将该电阻直接并联于直流回路上,用于分流和减小直流电流的幅值.另外,在与该电阻元件并联的直流回路上设置了一台断路器装置,该装置能开断较小容量的直流回路,它能与主直流回路的断路器共同工作,最终开断大幅值直流电流.在Matlab/Simulink环境下,建立Mayr电弧模型,并在此基础上建立了新型高压直流断路器模型.通过仿真及其分析,表明在高压直流系统中,该新型直流断路器具有很好的直流开断能力.

  3. 高压直流断路器系统开断条件仿真研究%Simulation Study on the Breaking Conditions of HVDC Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    姚远; 刘平; 刘朴; 姚斯立; 杜炜

    2015-01-01

    为分析高压直流断路器在实际高压直流输电系统中的各种故障情况及其开断条件,笔者利用PSCAD/EMTDC仿真软件,根据高压直流输电系统的结构和控制方式,搭建了背靠背高压直流输电系统仿真模型.仿真研究了单端高压直流输电系统不同位置发生单相、异相、三相及直流母线短路等故障情况下的暂态特性.仿真结果表明,该仿真模型有很好的动态响应特性,能够有效模拟单端高压直流输电系统的各种短路情况.同时,结合高压直流系统的控制方式对各种短路情况进行了研究分析,找出了在系统中对高压直流断路器的开断较为苛刻的情况.经过参数分析得到了各种不同故障情况下对直流断路器的开断影响较大的故障电流峰值、最大故障电流上升率等系统参数.从而为多端高压直流输电网络建模分析、高压直流断路器型式试验及其标准的制定、高压直流断路器的发展提供借鉴.

  4. Topological Analysis of HVDC Circuit Breaker With Coupling Transformer%串入耦合变压器高压直流断路器拓扑分析

    Institute of Scientific and Technical Information of China (English)

    刘远; 曹均正; 魏晓光; 张升; 王成昊; 高冲

    2015-01-01

    常规能源的稀缺,加快了以清洁能源为主导的全球互联坚强智能电网的构建.大规模清洁能源接入电网,推动了直流电网技术的进步.而高压直流断路器作为直流电网的核心设备之一,近年来渐渐成为研究热点.相比较交流电流,直流电流无自然过零点,分断难度大,在高压大容量系统中尤为明显.在简要回顾直流断路器研究现状之后,提出一种带耦合变压器的无弧分断高压直流断路器拓扑.给出拓扑结构,分析其工作原理.建立各阶段等效模型,并在此基础上对关键组件参数进行设计.以舟山5端柔性直流输电工程为依据,开展断路器仿真研究,验证理论分析的正确性,仿真结果表明:该拓扑直流断路器能有效开断直流电流,为直流断路器的设计提供了依据.

  5. Analysis and Treatment of SFC Input Circuit Breaker%SFC输入断路器未合闸原因分析及改进措施

    Institute of Scientific and Technical Information of China (English)

    蒋明君; 章亮; 潘菊芳; 孟玲

    2016-01-01

    本文对某抽水蓄能电站机组SFC输入断路器未合闸原因进行了细致地分析,特别是对SFC输入断路器合闸回路、逻辑图、断路器本体机构进行了详细分析,对SFC输入断路器端子和SFC输入断路器运行维护提出了改进措施,并对机组拖动回路运行维护提出了建议.

  6. Circuit breaker provides overcurrent and precise overvoltage protection%提供过电流和过电压保护的断路器

    Institute of Scientific and Technical Information of China (English)

    Anthony H Smith

    2007-01-01

    图1中的断路器仅需几个廉价的元件.即可对过电流和过电压故障状态进行反应。电路的核心是可调节的精密分路电压调节器D2,置在一只3引脚的封装中.提供了电压参考、比较器和集电极开路输出。

  7. PASS断路器系统在变电站的应用研究%Application and Study of PASS Circuit Breaker System in Substation

    Institute of Scientific and Technical Information of China (English)

    韩志萍; 曹鑫

    2006-01-01

    PASS断路器系统是ABB公司在多年生产气体绝缘组合电器(GIS)和空气绝缘开关电器(AIS)的基础上开发的一种新型的成套电器设备.本文介绍了PASS断路器系统的构成和适用的范围,分析了PASS断路器的优点和缺点.

  8. Computational non-chemically equilibrium model on the current zero simulation in a model N2 circuit breaker under the free recovery condition

    Science.gov (United States)

    Sun, Hao; Tanaka, Yasunori; Tomita, Kentaro; Wu, Yi; Rong, Mingzhe; Uesugi, Yoshihiko; Ishijima, Tatsuo

    2016-02-01

    A non-chemically equilibrium (non-CE) model was established to investigate the N2 arc plasma in the decaying phase during the arc interruption, and was validated by comparison with the experimental results based on laser Thomson scattering. Unlike the conventional model assuming the local thermodynamic equilibrium (LTE), in this non-CE model, the magneto-hydro-dynamics (MHD) method was coupled with the reaction kinetics to obtain the time-dependent species compositions and properties. The current calculation took into account five species in hot gas and 22 chemical reactions in total. The time-dependent species compositions of hot N2 were derived from the mass conservation equation for each species, considering the effect of the convection, diffusion and the chemical reaction. The influence of the non-CE compositions on the arc decaying behavior was realized by updating the thermodynamic and transport properties at each iterative step. The results indicate that the non-CE model can result in the departure of the arc decaying behavior from the LTE model, because it alters the time evolution of the species composition and consequently changes the thermodynamic and transport properties. At the edge of the arc, the time evolutions of the species are dominant by both the diffusion and the chemical reactions while at the center of the arc they are mainly influenced by the chemical reactions. Generally, the non-CE effect can lead to the delay of all the particles’ variations, particularly the electron decay, so that the arc interruption performance will be reduced compared with that in the LTE model.

  9. 低压断路器热脱扣稳定性的研究%Study on Thermal Test Stability for Low Voltage Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    胡金利

    2015-01-01

    介绍了低压断路器的热脱扣特性及其执行元件,分析了热脱扣特性的缺陷.探讨了双金属的计算公式,推导了双金属能量计算及应用,验证了双金属能量法在热脱扣测试稳定性研究中的运用,提出并验证了双金属初始位置对热脱扣稳定性的影响.

  10. Changes to the shuttle circuits

    CERN Multimedia

    GS Department

    2011-01-01

    To fit with passengers expectation, there will be some changes to the shuttle circuits as from Monday 10 October. See details on http://cern.ch/ShuttleService (on line on 7 October). Circuit No. 5 is cancelled as circuit No. 1 also stops at Bldg. 33. In order to guarantee shorter travel times, circuit No. 1 will circulate on Meyrin site only and circuit No. 2, with departures from Bldg. 33 and 500, on Prévessin site only. Site Services Section

  11. Power system with an integrated lubrication circuit

    Science.gov (United States)

    Hoff, Brian D.; Akasam, Sivaprasad; Algrain, Marcelo C.; Johnson, Kris W.; Lane, William H.

    2009-11-10

    A power system includes an engine having a first lubrication circuit and at least one auxiliary power unit having a second lubrication circuit. The first lubrication circuit is in fluid communication with the second lubrication circuit.

  12. Design, Fabrication and pseudo Field Evaluation of a Sugar Beet Crust Breaker and Weeding Unit Equipped with an Infrared Sensor

    Directory of Open Access Journals (Sweden)

    E Chaligar

    2014-09-01

    Full Text Available In conventional cultivation of sugar beet the weeding and crust breaking are mostly performed manually. The objectives of this research were to design, fabricate and evaluate a soil crust breaker and weeding implement equipped with a detecting sensor. Each unit consisted of a distance detecting sensor and a hydro-motor for driving the blades and pneumatic valves for moving the blades. The hydro-motor was activated by the sensors. To avoid damaging the plants, a command signal was sent to the pneumatic valves to move the blades up and down and pass safely. Three configurations of cutting blades were considered which could be mounted to the crust breaker. The field evaluation was conducted with two tractor forward speeds (0.4 and 1 km h-1 and four plant-to-plant spacings within rows (20, 25, 30 and 40 cm all with three different blade shapes. For field evaluation split plot experiments arranged in a completely randomized block design with three replications. The number of plants damaged (evaluated only for four-lobe blades and size of broken crusts (evaluated for all blade shapes for various treatments were recorded and compared. The results of analysis indicated that the higher the inter-row spacing the lower the injury to the plant. The highest and the least damage to the plants occurred for within-row plant spacings of 20 and 40 cm, respectively. The forward speed was also significantly affected the percent of plant damaged. The forward speed of 1 km h-1 at 20 cm spacing had the most (59% and the speed of 0.40 km h-1 at 40 cm spacing had the least effect (3.3% on the percent of plant damage. The two-lobe blade could result in the maximum surface area broken.

  13. Scaled photographs of surf over the full range of breaker sizes on the north shore of Oahu and Jaws, Maui, Hawaiian Islands, January 1998 - May 2004 (NODC Accession 0001753)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Digital surf photographs were scaled using surfers as height benchmarks to estimate the size of the breakers. Historical databases for surf height in Hawaii are...

  14. Memristor based startup circuit for self biased circuits

    Science.gov (United States)

    Das, Mangal; Singh, Amit Kumar; Rathi, Amit; Singhal, Sonal

    2016-04-01

    This paper presents the design of a Memristor based startup circuit for self biased circuits. Memristor has many advantages over conventional CMOS devices such as low leakage current at nanometer scale, easy to manufacture. In this work the switching characteristics of memristor is utilized. First the theoretical equations describing the switching behavior of memristor are investigated. To prove the switching capability of Memristor, a startup circuit based on memristor is proposed which uses series combination of Memristor and capacitor. Proposed circuit is compared with the previously reported MOSFET based startup circuits. Comparison of different circuits was done to validate the results. Simulation results show that memristor based circuit can attain on (I = 12.94 µA) to off state (I = 1 .2 µA) in 25 ns while the MOSFET based startup circuits take on (I = 14.19 µA) to off state (I = 1.4 µA) in more than 90 ns. The benefit comes in terms of area because the number of components used in the circuit are lesser than the conventional startup circuits.

  15. Photonic Integrated Circuits

    Science.gov (United States)

    Krainak, Michael; Merritt, Scott

    2016-01-01

    Integrated photonics generally is the integration of multiple lithographically defined photonic and electronic components and devices (e.g. lasers, detectors, waveguides passive structures, modulators, electronic control and optical interconnects) on a single platform with nanometer-scale feature sizes. The development of photonic integrated circuits permits size, weight, power and cost reductions for spacecraft microprocessors, optical communication, processor buses, advanced data processing, and integrated optic science instrument optical systems, subsystems and components. This is particularly critical for small spacecraft platforms. We will give an overview of some NASA applications for integrated photonics.

  16. Electronic logic circuits

    CERN Document Server

    Gibson, J

    2013-01-01

    Most branches of organizing utilize digital electronic systems. This book introduces the design of such systems using basic logic elements as the components. The material is presented in a straightforward manner suitable for students of electronic engineering and computer science. The book is also of use to engineers in related disciplines who require a clear introduction to logic circuits. This third edition has been revised to encompass the most recent advances in technology as well as the latest trends in components and notation. It includes a wide coverage of application specific integrate

  17. Electronics circuits and systems

    CERN Document Server

    Bishop, Owen

    2011-01-01

    The material in Electronics - Circuits and Systems is a truly up-to-date textbook, with coverage carefully matched to the electronics units of the 2007 BTEC National Engineering and the latest AS and A Level specifications in Electronics from AQA, OCR and WJEC. The material has been organized with a logical learning progression, making it ideal for a wide range of pre-degree courses in electronics. The approach is student-centred and includes: numerous examples and activities; web research topics; Self Test features, highlighted key facts, formulae and definitions. Ea

  18. Linear integrated circuits

    CERN Document Server

    Carr, Joseph

    1996-01-01

    The linear IC market is large and growing, as is the demand for well trained technicians and engineers who understand how these devices work and how to apply them. Linear Integrated Circuits provides in-depth coverage of the devices and their operation, but not at the expense of practical applications in which linear devices figure prominently. This book is written for a wide readership from FE and first degree students, to hobbyists and professionals.Chapter 1 offers a general introduction that will provide students with the foundations of linear IC technology. From chapter 2 onwa

  19. Optoelectronics circuits manual

    CERN Document Server

    Marston, R M

    1999-01-01

    This manual is a useful single-volume guide specifically aimed at the practical design engineer, technician, and experimenter, as well as the electronics student and amateur. It deals with the subject in an easy to read, down to earth, and non-mathematical yet comprehensive manner, explaining the basic principles and characteristics of the best known devices, and presenting the reader with many practical applications and over 200 circuits. Most of the ICs and other devices used are inexpensive and readily available types, with universally recognised type numbers.The second edition

  20. Nano integrated circuit process

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Yung Sup

    2004-02-15

    This book contains nine chapters, which are introduction of manufacture of semiconductor chip, oxidation such as Dry-oxidation, wet oxidation, oxidation model and oxide film, diffusion like diffusion process, diffusion equation, diffusion coefficient and diffusion system, ion implantation, including ion distribution, channeling, multiimplantation and masking and its system, sputtering such as CVD and PVD, lithography, wet etch and dry etch, interconnection and flattening like metal-silicon connection, silicide, multiple layer metal process and flattening, an integrated circuit process, including MOSFET and CMOS.

  1. Electronics circuits and systems

    CERN Document Server

    Bishop, Owen

    2007-01-01

    The material in Electronics - Circuits and Systems is a truly up-to-date textbook, with coverage carefully matched to the electronics units of the 2007 BTEC National Engineering and the latest AS and A Level specifications in Electronics from AQA, OCR and WJEC. The material has been organized with a logical learning progression, making it ideal for a wide range of pre-degree courses in electronics. The approach is student-centred and includes: numerous examples and activities; web research topics; Self Test features, highlighted key facts, formulae and definitions. Each chapter ends with a set

  2. Electric circuits problem solver

    CERN Document Server

    REA, Editors of

    2012-01-01

    Each Problem Solver is an insightful and essential study and solution guide chock-full of clear, concise problem-solving gems. All your questions can be found in one convenient source from one of the most trusted names in reference solution guides. More useful, more practical, and more informative, these study aids are the best review books and textbook companions available. Nothing remotely as comprehensive or as helpful exists in their subject anywhere. Perfect for undergraduate and graduate studies.Here in this highly useful reference is the finest overview of electric circuits currently av

  3. Sequential circuit design for radiation hardened multiple voltage integrated circuits

    Science.gov (United States)

    Clark, Lawrence T.; McIver, III, John K.

    2009-11-24

    The present invention includes a radiation hardened sequential circuit, such as a bistable circuit, flip-flop or other suitable design that presents substantial immunity to ionizing radiation while simultaneously maintaining a low operating voltage. In one embodiment, the circuit includes a plurality of logic elements that operate on relatively low voltage, and a master and slave latches each having storage elements that operate on a relatively high voltage.

  4. 49 CFR 236.13 - Spring switch; selection of signal control circuits through circuit controller.

    Science.gov (United States)

    2010-10-01

    ... circuits through circuit controller. 236.13 Section 236.13 Transportation Other Regulations Relating to...; selection of signal control circuits through circuit controller. The control circuits of signals governing... circuit controller, or through the contacts of relay repeating the position of such circuit...

  5. Quasi-Linear Circuit

    Science.gov (United States)

    Bradley, William; Bird, Ross; Eldred, Dennis; Zook, Jon; Knowles, Gareth

    2013-01-01

    This work involved developing spacequalifiable switch mode DC/DC power supplies that improve performance with fewer components, and result in elimination of digital components and reduction in magnetics. This design is for missions where systems may be operating under extreme conditions, especially at elevated temperature levels from 200 to 300 degC. Prior art for radiation-tolerant DC/DC converters has been accomplished utilizing classical magnetic-based switch mode converter topologies; however, this requires specific shielding and component de-rating to meet the high-reliability specifications. It requires complex measurement and feedback components, and will not enable automatic re-optimization for larger changes in voltage supply or electrical loading condition. The innovation is a switch mode DC/DC power supply that eliminates the need for processors and most magnetics. It can provide a well-regulated voltage supply with a gain of 1:100 step-up to 8:1 step down, tolerating an up to 30% fluctuation of the voltage supply parameters. The circuit incorporates a ceramic core transformer in a manner that enables it to provide a well-regulated voltage output without use of any processor components or magnetic transformers. The circuit adjusts its internal parameters to re-optimize its performance for changes in supply voltage, environmental conditions, or electrical loading at the output

  6. Automated Design of Quantum Circuits

    Science.gov (United States)

    Williams, Colin P.; Gray, Alexander G.

    2000-01-01

    In order to design a quantum circuit that performs a desired quantum computation, it is necessary to find a decomposition of the unitary matrix that represents that computation in terms of a sequence of quantum gate operations. To date, such designs have either been found by hand or by exhaustive enumeration of all possible circuit topologies. In this paper we propose an automated approach to quantum circuit design using search heuristics based on principles abstracted from evolutionary genetics, i.e. using a genetic programming algorithm adapted specially for this problem. We demonstrate the method on the task of discovering quantum circuit designs for quantum teleportation. We show that to find a given known circuit design (one which was hand-crafted by a human), the method considers roughly an order of magnitude fewer designs than naive enumeration. In addition, the method finds novel circuit designs superior to those previously known.

  7. CMOS Nonlinear Signal Processing Circuits

    OpenAIRE

    2010-01-01

    The chapter describes various nonlinear signal processing CMOS circuits, including a high reliable WTA/LTA, simple MED cell, and low-voltage arbitrary order extractor. We focus the discussion on CMOS analog circuit design with reliable, programmable capability, and low voltage operation. It is a practical problem when the multiple identical cells are required to match and realized within a single chip using a conventional process. Thus, the design of high-reliable circuit is indeed needed. Th...

  8. Analog electronic neural network circuits

    Energy Technology Data Exchange (ETDEWEB)

    Graf, H.P.; Jackel, L.D. (AT and T Bell Labs., Holmdel, NJ (USA))

    1989-07-01

    The large interconnectivity and moderate precision required in neural network models present new opportunities for analog computing. This paper discusses analog circuits for a variety of problems such as pattern matching, optimization, and learning. Most of the circuits build so far are relatively small, exploratory designs. The most mature circuits are those for template matching. Chips performing this function are now being applied to pattern recognition problems.

  9. Transistor switching and sequential circuits

    CERN Document Server

    Sparkes, John J

    1969-01-01

    Transistor Switching and Sequential Circuits presents the basic ideas involved in the construction of computers, instrumentation, pulse communication systems, and automation. This book discusses the design procedure for sequential circuits. Organized into two parts encompassing eight chapters, this book begins with an overview of the ways on how to generate the types of waveforms needed in digital circuits, principally ramps, square waves, and delays. This text then considers the behavior of some simple circuits, including the inverter, the emitter follower, and the long-tailed pair. Other cha

  10. Unstable oscillators based hyperchaotic circuit

    DEFF Research Database (Denmark)

    Murali, K.; Tamasevicius, A.; G. Mykolaitis, A.;

    1999-01-01

    A simple 4th order hyperchaotic circuit with unstable oscillators is described. The circuit contains two negative impedance converters, two inductors, two capacitors, a linear resistor and a diode. The Lyapunov exponents are presented to confirm hyperchaotic nature of the oscillations in the circ......A simple 4th order hyperchaotic circuit with unstable oscillators is described. The circuit contains two negative impedance converters, two inductors, two capacitors, a linear resistor and a diode. The Lyapunov exponents are presented to confirm hyperchaotic nature of the oscillations...

  11. 77 FR 812 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Science.gov (United States)

    2012-01-06

    ... smaller than No. 4 AWG. (3) All circuit breakers used to protect the No. 2 AWG trailing cables that exceed... setting of these circuit breakers will be sealed and will have permanent, legible labels. The labels will identify the circuit breaker as being a specially calibrated circuit breaker suitable for protecting No....

  12. A Circuit to Demonstrate Phase Relationships in "RLC" Circuits

    Science.gov (United States)

    Sokol, P. E.; Warren, G.; Zheng, B.; Smith, P.

    2013-01-01

    We have developed a circuit to demonstrate the phase relationships between resistive and reactive elements in series "RLC" circuits. We utilize a differential amplifier to allow the phases of the three elements and the current to be simultaneously displayed on an inexpensive four channel oscilloscope. We have included a novel circuit…

  13. VLSI circuits implementing computational models of neocortical circuits.

    Science.gov (United States)

    Wijekoon, Jayawan H B; Dudek, Piotr

    2012-09-15

    This paper overviews the design and implementation of three neuromorphic integrated circuits developed for the COLAMN ("Novel Computing Architecture for Cognitive Systems based on the Laminar Microcircuitry of the Neocortex") project. The circuits are implemented in a standard 0.35 μm CMOS technology and include spiking and bursting neuron models, and synapses with short-term (facilitating/depressing) and long-term (STDP and dopamine-modulated STDP) dynamics. They enable execution of complex nonlinear models in accelerated-time, as compared with biology, and with low power consumption. The neural dynamics are implemented using analogue circuit techniques, with digital asynchronous event-based input and output. The circuits provide configurable hardware blocks that can be used to simulate a variety of neural networks. The paper presents experimental results obtained from the fabricated devices, and discusses the advantages and disadvantages of the analogue circuit approach to computational neural modelling.

  14. A dishwasher for circuits

    CERN Multimedia

    Rosaria Marraffino

    2014-01-01

    You have always been told that electronic devices fear water. However, at the Surface Mount Devices (SMD) Workshop here at CERN all the electronic assemblies are cleaned with a machine that looks like a… dishwasher.   The circuit dishwasher. Credit: Clara Nellist.  If you think the image above shows a dishwasher, you wouldn’t be completely wrong. Apart from the fact that the whole pumping system and the case itself are made entirely from stainless steel and chemical resistant materials, and the fact that it washes electrical boards instead of dishes… it works exactly like a dishwasher. It’s a professional machine (mainly used in the pharmaceutical industry) designed to clean everything that can be washed with a water-based chemical soap. This type of treatment increases the lifetime of the electronic boards and therefore the LHC's reliability by preventing corrosion problems in the severe radiation and ozone environment of the LHC tunn...

  15. Basic electronic circuits

    CERN Document Server

    Buckley, P M

    1980-01-01

    In the past, the teaching of electricity and electronics has more often than not been carried out from a theoretical and often highly academic standpoint. Fundamentals and basic concepts have often been presented with no indication of their practical appli­ cations, and all too frequently they have been illustrated by artificially contrived laboratory experiments bearing little relationship to the outside world. The course comes in the form of fourteen fairly open-ended constructional experiments or projects. Each experiment has associated with it a construction exercise and an explanation. The basic idea behind this dual presentation is that the student can embark on each circuit following only the briefest possible instructions and that an open-ended approach is thereby not prejudiced by an initial lengthy encounter with the theory behind the project; this being a sure way to dampen enthusiasm at the outset. As the investigation progresses, questions inevitably arise. Descriptions of the phenomena encounte...

  16. Memristor Circuits and Systems

    KAUST Repository

    Zidan, Mohammed A.

    2015-05-01

    Current CMOS-based technologies are facing design challenges related to the continuous scaling down of the minimum feature size, according to Moore’s law. Moreover, conventional computing architecture is no longer an effective way of fulfilling modern applications demands, such as big data analysis, pattern recognition, and vector processing. Therefore, there is an exigent need to shift to new technologies, at both the architecture and the device levels. Recently, memristor devices and structures attracted attention for being promising candidates for this job. Memristor device adds a new dimension for designing novel circuits and systems. In addition, high-density memristor-based crossbar is widely considered to be the essential element for future memory and bio-inspired computing systems. However, numerous challenges need to be addressed before the memristor genuinely replaces current memory and computing technologies, which is the motivation behind this research effort. In order to address the technology challenges, we begin by fabricating and modeling the memristor device. The devices fabricated at our local clean room enriched our understanding of the memristive phenomenon and enabled the experimental testing for our memristor-based circuits. Moreover, our proposed mathematical modeling for memristor behavior is an essential element for the theoretical circuit design stage. Designing and addressing the challenges of memristor systems with practical complexity, however, requires an extra step, which takes the form of a reliable and modular simulation platform. We, therefore, built a new simulation platform for the resistive crossbar, which can simulate realistic size arrays filled with real memory data. In addition, this simulation platform includes various crossbar nonidealities in order to obtain accurate simulation results. Consequently, we were able to address the significant challenges facing the high density memristor crossbar, as the building block for

  17. Diamond Integrated Optomechanical Circuits

    CERN Document Server

    Rath, Patrik; Nebel, Christoph; Wild, Christoph; Pernice, Wolfram H P

    2013-01-01

    Diamond offers unique material advantages for the realization of micro- and nanomechanical resonators due to its high Young's modulus, compatibility with harsh environments and superior thermal properties. At the same time, the wide electronic bandgap of 5.45eV makes diamond a suitable material for integrated optics because of broadband transparency and the absence of free-carrier absorption commonly encountered in silicon photonics. Here we take advantage of both to engineer full-scale optomechanical circuits in diamond thin films. We show that polycrystalline diamond films fabricated by chemical vapour deposition provide a convenient waferscale substrate for the realization of high quality nanophotonic devices. Using free-standing nanomechanical resonators embedded in on-chip Mach-Zehnder interferometers, we demonstrate efficient optomechanical transduction via gradient optical forces. Fabricated diamond resonators reproducibly show high mechanical quality factors up to 11,200. Our low cost, wideband, carri...

  18. Modeling cortical circuits.

    Energy Technology Data Exchange (ETDEWEB)

    Rohrer, Brandon Robinson; Rothganger, Fredrick H.; Verzi, Stephen J.; Xavier, Patrick Gordon

    2010-09-01

    The neocortex is perhaps the highest region of the human brain, where audio and visual perception takes place along with many important cognitive functions. An important research goal is to describe the mechanisms implemented by the neocortex. There is an apparent regularity in the structure of the neocortex [Brodmann 1909, Mountcastle 1957] which may help simplify this task. The work reported here addresses the problem of how to describe the putative repeated units ('cortical circuits') in a manner that is easily understood and manipulated, with the long-term goal of developing a mathematical and algorithmic description of their function. The approach is to reduce each algorithm to an enhanced perceptron-like structure and describe its computation using difference equations. We organize this algorithmic processing into larger structures based on physiological observations, and implement key modeling concepts in software which runs on parallel computing hardware.

  19. Short-circuit impedance measurement

    DEFF Research Database (Denmark)

    Pedersen, Knud Ole Helgesen; Nielsen, Arne Hejde; Poulsen, Niels Kjølstad

    2003-01-01

    Methods for estimating the short-circuit impedance in the power grid are investigated for various voltage levels and situations. The short-circuit impedance is measured, preferably from naturally occurring load changes in the grid, and it is shown that such a measurement system faces different...

  20. Comminution circuits for compact itabirites

    Directory of Open Access Journals (Sweden)

    Pedro Ferreira Pinto

    Full Text Available Abstract In the beneficiation of compact Itabirites, crushing and grinding account for major operational and capital costs. As such, the study and development of comminution circuits have a fundamental importance for feasibility and optimization of compact Itabirite beneficiation. This work makes a comparison between comminution circuits for compact Itabirites from the Iron Quadrangle. The circuits developed are: a crushing and ball mill circuit (CB, a SAG mill and ball mill circuit (SAB and a single stage SAG mill circuit (SSSAG. For the SAB circuit, the use of pebble crushing is analyzed (SABC. An industrial circuit for 25 million tons of run of mine was developed for each route from tests on a pilot scale (grinding and industrial scale. The energy consumption obtained for grinding in the pilot tests was compared with that reported by Donda and Bond. The SSSAG route had the lowest energy consumption, 11.8kWh/t and the SAB route had the highest energy consumption, 15.8kWh/t. The CB and SABC routes had a similar energy consumption of 14.4 kWh/t and 14.5 kWh/t respectively.

  1. Dive In to Aquatic Circuits.

    Science.gov (United States)

    Goldfarb, Joseph M.

    1995-01-01

    The article presents a method for swimming teachers and coaches to stave off workout boredom in their students by using a circuit in the pool. After explaining how to set up a training circuit, the article describes sample stations and notes important safety precautions. (SM)

  2. Sequential Polarity-Reversing Circuit

    Science.gov (United States)

    Labaw, Clayton C.

    1994-01-01

    Proposed circuit reverses polarity of electric power supplied to bidirectional dc motor, reversible electro-mechanical actuator, or other device operating in direction depending on polarity. Circuit reverses polarity each time power turned on, without need for additional polarity-reversing or direction signals and circuitry to process them.

  3. Logic Circuit Design Selected Methods

    CERN Document Server

    Vingron, Shimon P

    2012-01-01

        In three main divisions the  book covers combinational circuits, latches, and asynchronous sequential circuits. Combinational circuits have  no memorising ability, while sequential circuits have such an ability to various degrees. Latches are the simplest sequential circuits, ones with the shortest memory. The presentation is decidedly non-standard.         The design of combinational circuits is discussed in an orthodox manner using normal forms and in an unorthodox manner using set-theoretical evaluation formulas relying heavily on Karnaugh maps. The latter approach allows for a new design technique called composition.          Latches are covered very extensively. Their memory functions are expressed mathematically in a time-independent manner allowing the use of (normal, non-temporal) Boolean logic in their calculation. The theory of latches is then used as the basis for calculating asynchronous circuits.         Asynchronous circuits are specified in a tree-representation, eac...

  4. Enhancement of Linear Circuit Program

    DEFF Research Database (Denmark)

    Gaunholt, Hans; Dabu, Mihaela; Beldiman, Octavian

    1996-01-01

    In this report a preliminary user friendly interface has been added to the LCP2 program making it possible to describe an electronic circuit by actually drawing the circuit on the screen. Component values and other options and parameters can easily be set by the aid of the interface. The interfac...

  5. Accurate Switched-Voltage voltage averaging circuit

    OpenAIRE

    金光, 一幸; 松本, 寛樹

    2006-01-01

    Abstract ###This paper proposes an accurate Switched-Voltage (SV) voltage averaging circuit. It is presented ###to compensated for NMOS missmatch error at MOS differential type voltage averaging circuit. ###The proposed circuit consists of a voltage averaging and a SV sample/hold (S/H) circuit. It can ###operate using nonoverlapping three phase clocks. Performance of this circuit is verified by PSpice ###simulations.

  6. Photodiode circuits for retinal prostheses.

    Science.gov (United States)

    Loudin, J D; Cogan, S F; Mathieson, K; Sher, A; Palanker, D V

    2011-10-01

    Photodiode circuits show promise for the development of high-resolution retinal prostheses. While several of these systems have been constructed and some even implanted in humans, existing descriptions of the complex optoelectronic interaction between light, photodiode, and the electrode/electrolyte load are limited. This study examines this interaction in depth with theoretical calculations and experimental measurements. Actively biased photoconductive and passive photovoltaic circuits are investigated, with the photovoltaic circuits consisting of one or more diodes connected in series, and the photoconductive circuits consisting of a single diode in series with a pulsed bias voltage. Circuit behavior and charge injection levels were markedly different for platinum and sputtered iridium-oxide film (SIROF) electrodes. Photovoltaic circuits were able to deliver 0.038 mC/cm(2) (0.75 nC/phase) per photodiode with 50- μm platinum electrodes, and 0.54-mC/cm(2) (11 nC/phase) per photodiode with 50-μ m SIROF electrodes driven with 0.5-ms pulses of light at 25 Hz. The same pulses applied to photoconductive circuits with the same electrodes were able to deliver charge injections as high as 0.38 and 7.6 mC/cm(2) (7.5 and 150 nC/phase), respectively. We demonstrate photovoltaic stimulation of rabbit retina in-vitro, with 0.5-ms pulses of 905-nm light using peak irradiance of 1 mW/mm(2). Based on the experimental data, we derive electrochemical and optical safety limits for pixel density and charge injection in various circuits. While photoconductive circuits offer smaller pixels, photovoltaic systems do not require an external bias voltage. Both classes of circuits show promise for the development of high-resolution optoelectronic retinal prostheses.

  7. Experimental Device for Learning of Logical Circuit Design using Integrated Circuits

    OpenAIRE

    石橋, 孝昭

    2012-01-01

    This paper presents an experimental device for learning of logical circuit design using integrated circuits and breadboards. The experimental device can be made at a low cost and can be used for many subjects such as logical circuits, computer engineering, basic electricity, electrical circuits and electronic circuits. The proposed device is effective to learn the logical circuits than the usual lecture.

  8. Performance analysis of electrical circuits /PANE/

    Science.gov (United States)

    Johnson, K. L.; Steinberg, L. L.

    1968-01-01

    Automated statistical and worst case computer program has been designed to perform dc and ac steady circuit analyses. The program determines the worst case circuit performance by solving circuit equations.

  9. Variational integrators for electric circuits

    Energy Technology Data Exchange (ETDEWEB)

    Ober-Blöbaum, Sina, E-mail: sinaob@math.upb.de [Computational Dynamics and Optimal Control, University of Paderborn (Germany); Tao, Molei [Courant Institute of Mathematical Sciences, New York University (United States); Cheng, Mulin [Applied and Computational Mathematics, California Institute of Technology (United States); Owhadi, Houman; Marsden, Jerrold E. [Control and Dynamical Systems, California Institute of Technology (United States); Applied and Computational Mathematics, California Institute of Technology (United States)

    2013-06-01

    In this contribution, we develop a variational integrator for the simulation of (stochastic and multiscale) electric circuits. When considering the dynamics of an electric circuit, one is faced with three special situations: 1. The system involves external (control) forcing through external (controlled) voltage sources and resistors. 2. The system is constrained via the Kirchhoff current (KCL) and voltage laws (KVL). 3. The Lagrangian is degenerate. Based on a geometric setting, an appropriate variational formulation is presented to model the circuit from which the equations of motion are derived. A time-discrete variational formulation provides an iteration scheme for the simulation of the electric circuit. Dependent on the discretization, the intrinsic degeneracy of the system can be canceled for the discrete variational scheme. In this way, a variational integrator is constructed that gains several advantages compared to standard integration tools for circuits; in particular, a comparison to BDF methods (which are usually the method of choice for the simulation of electric circuits) shows that even for simple LCR circuits, a better energy behavior and frequency spectrum preservation can be observed using the developed variational integrator.

  10. Determining Covers in Combinational Circuits

    Directory of Open Access Journals (Sweden)

    Ljubomir Cvetkovic

    2011-05-01

    Full Text Available In this paper we propose a procedure for determining 0- or 1-cover of an arbitrary line in a combinational circuit. When determining a cover we do not need Boolean expression for the line; only the circuit structure is used. Within the proposed procedure we use the tools of the cube theory, in particular, some operations defined on cubes. The procedure can be applied for determining 0- and 1- covers of output lines in programmable logic devices. Basically, this procedure is a method for the analysis of a combinational circuit.

  11. Overpulse railgun energy recovery circuit

    Energy Technology Data Exchange (ETDEWEB)

    Honig, E.M.

    1984-09-28

    The invention presented relates to a high-power pulsing circuit and more particularly to a repetitive pulse inductive energy storage and transfer circuit for an electromagnetic launcher. In an electromagnetic launcher such as a railgun for propelling a projectile at high velocity, an overpulse energy recovery circuit is employed to transfer stored inductive energy from a source inductor to the railgun inductance to propel the projectile down the railgun. Switching circuitry and an energy transfer capacitor are used to switch the energy back to the source inductor in readiness for a repetitive projectile propelling cycle.

  12. Counterpulse railgun energy recovery circuit

    Energy Technology Data Exchange (ETDEWEB)

    Honig, E.M.

    1984-09-28

    The invention presented relates to a high-power pulsing circuit and more particularly to a repetitive pulse inductive energy storage and transfer circuit for an electromagnetic launcher. In an electromagnetic launcher such as a railgun for propelling a projectile at high velocity, a counterpulse energy recovery circuit is employed to transfer stored inductive energy from a source inductor to the railgun inductance to propel the projectile down the railgun. Switching circuitry and an energy transfer capacitor are used to switch the energy back to the source inductor in readiness for a repetitive projectile propelling cycle.

  13. Secure integrated circuits and systems

    CERN Document Server

    Verbauwhede, Ingrid MR

    2010-01-01

    On any advanced integrated circuit or 'system-on-chip' there is a need for security. In many applications the actual implementation has become the weakest link in security rather than the algorithms or protocols. The purpose of the book is to give the integrated circuits and systems designer an insight into the basics of security and cryptography from the implementation point of view. As a designer of integrated circuits and systems it is important to know both the state-of-the-art attacks as well as the countermeasures. Optimizing for security is different from optimizations for speed, area,

  14. The Maplin electronic circuits handbook

    CERN Document Server

    Tooley, Michael

    2015-01-01

    The Maplin Electronic Circuits Handbook provides pertinent data, formula, explanation, practical guidance, theory and practical guidance in the design, testing, and construction of electronic circuits. This book discusses the developments in electronics technology techniques.Organized into 11 chapters, this book begins with an overview of the common types of passive component. This text then provides the reader with sufficient information to make a correct selection of passive components for use in the circuits. Other chapters consider the various types of the most commonly used semiconductor

  15. A Current-Limiting HVDC Circuit Breaker with Equalizing Circuit%一种含有均压均流电路的限流式高压直流断路器

    Institute of Scientific and Technical Information of China (English)

    陈可; 江道灼; 谢峰; 杜翼

    2015-01-01

    针对混合式直流断路器电力电子器件依靠燃弧电压导通,极易出现过压过流等问题,提出了一种新型限流式直流断路器拓扑,设计了其固态开关的均压均流电路,并对其进行建模分析.所提出的拓扑在断路器正常运行时无额外损耗,在短路故障发生时可以无延时地导通固态开关,并快速切断短路电流,其均压均流电路在不影响故障切除的同时能有效均衡各电力电子器件的电压电流.最后对所提拓扑在PSCAD/EMTDC软件平台上进行建模仿真,结果表明提出的新型限流式直流断路器能够在短路故障发生时有效限制短路电流上升,快速切断故障,并可靠地保护固态开关.

  16. 一种适于快速高压直流断路器的过零振荡电路%An Oscillating Circuit Applied to High-speed HVDC Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    李黎; 程勇; 俞斌; 刘云龙; 袁召; 林福昌; 潘垣

    2016-01-01

    为满足高电压等级直流断路器可靠地快速开断故障电流的要求,提出了一种基于多级串联间隙和电容分压自取电的预充电型直流断路器过零振荡电路.描述了带分压网络的多级串联间隙的工作原理,仿真分析了触发频率、横向均压电阻和纵向分压电容对多级串联间隙分压特性的影响,并对多级串联间隙在导通动作过程进行了实验验证.分析了基于电容分压自取电的触发装置原理以及参数配置要求.对此种断路器的短路故障电流开断过程进行了仿真分析,并建立电流模拟开断实验系统进行了振荡回路验证研究.仿真与初步的实验结果表明,该过零振荡电路可在主断口支路快速产生有效的反向振荡电流波形,实现故障电流的开断.

  17. 永磁真空断路器过零分断保护电路的研究与设计%Research and Design of Over Zero Breaking Protection Circuit of Permanent Magnetism Vacuum Circuit Breaker

    Institute of Scientific and Technical Information of China (English)

    赵洪梅

    2013-01-01

    为了避免断路器在大电流/电压下分断电路,产生电弧、电火花,对系统安全造成危害,对永磁真空断路器过零分断保护电路进行研究,设计了零点检测电路.该电路使得断路器在电压电流过零点时进行分合闸,达到无弧可灭的目的,提高了系统的安全性与可靠性.

  18. Cause analysis of circuit breaker tripping caused by AC power flowing into DC circuit%交流电源串入直流电源回路导致断路器跳合闸原因分析

    Institute of Scientific and Technical Information of China (English)

    赵永生; 庄洪波

    2010-01-01

    介绍2起多台断路器同时跳闸或合闸的典型事故,通过现场试验验证和分析,证明当交流电源串入直流电源回路中,可能引起多台断路器跳闸或合闸,并提出防范措施.

  19. Chaos Control for Chua's Circuits

    Science.gov (United States)

    Tôrres, L. A. B.; Aguirre, L. A.; Palhares, R. M.; Mendes, E. M. A. M.

    The practical implementation of Chua's circuit control methods is discussed in this chapter. In order to better address this subject, an inductorless Chua's circuit realization is first presented, followed by practical issues related to data analysis, mathematical modelling, and dynamical characterization associated to this electronic chaotic oscillator. As a consequence of the investigation of different control strategies applied to Chua's circuit, a tradeoff among control objective, control energy, and model complexity is devised, which quite naturally leads to a principle that seems to be of general nature: the Information Transmission Via Control (ITVC) for nonlinear oscillators. The main purpose of the present chapter is to serve as an introductory guide to the universe of Chua's circuit control, synchronization, and mathematical modelling.

  20. CADAT integrated circuit mask analysis

    Science.gov (United States)

    1981-01-01

    CADAT System Mask Analysis Program (MAPS2) is automated software tool for analyzing integrated-circuit mask design. Included in MAPS2 functions are artwork verification, device identification, nodal analysis, capacitance calculation, and logic equation generation.

  1. Circuit design on plastic foils

    CERN Document Server

    Raiteri, Daniele; Roermund, Arthur H M

    2015-01-01

    This book illustrates a variety of circuit designs on plastic foils and provides all the information needed to undertake successful designs in large-area electronics.  The authors demonstrate architectural, circuit, layout, and device solutions and explain the reasons and the creative process behind each. Readers will learn how to keep under control large-area technologies and achieve robust, reliable circuit designs that can face the challenges imposed by low-cost low-temperature high-throughput manufacturing.   • Discusses implications of problems associated with large-area electronics and compares them to standard silicon; • Provides the basis for understanding physics and modeling of disordered material; • Includes guidelines to quickly setup the basic CAD tools enabling efficient and reliable designs; • Illustrates practical solutions to cope with hard/soft faults, variability, mismatch, aging and bias stress at architecture, circuit, layout, and device levels.

  2. Wireless communications circuits and systems

    CERN Document Server

    Sun, Yichuang

    2004-01-01

    This new book examines integrated circuits, systems and transceivers for wireless and mobile communications. It covers the most recent developments in key RF, IF, analogue, mixed-signal components and single-chip transceivers in CMOS technology.

  3. Optimizing Transmission Line Matching Circuits

    OpenAIRE

    Novak, S.

    1996-01-01

    When designing transmission line matching circuits, there exist often overlooked, additional, not much used, degree of choice in the selection of the transmission line impedance. In this work are presented results of CAD analysis for the two element transmission line matching networks, demonstrating that selecting matching circuits transmission lines with higher impedance, than usually used 50 or 75 ohms, can in most cases substantially decrease the physical dimension of the final matching ci...

  4. Spinal sensory circuits in motion

    OpenAIRE

    2016-01-01

    International audience; The role of sensory feedback in shaping locomotion has been long debated. Recent advances in genetics and behavior analysis revealed the importance of proprioceptive pathways in spinal circuits. The mechanisms underlying peripheral mechanosensation enabled to unravel the networks that feedback to spinal circuits in order to modulate locomotion. Sensory inputs to the vertebrate spinal cord were long thought to originate from the periphery. Recent studies challenge this ...

  5. Neural Circuits on a Chip

    Directory of Open Access Journals (Sweden)

    Md. Fayad Hasan

    2016-09-01

    Full Text Available Neural circuits are responsible for the brain’s ability to process and store information. Reductionist approaches to understanding the brain include isolation of individual neurons for detailed characterization. When maintained in vitro for several days or weeks, dissociated neurons self-assemble into randomly connected networks that produce synchronized activity and are capable of learning. This review focuses on efforts to control neuronal connectivity in vitro and construct living neural circuits of increasing complexity and precision. Microfabrication-based methods have been developed to guide network self-assembly, accomplishing control over in vitro circuit size and connectivity. The ability to control neural connectivity and synchronized activity led to the implementation of logic functions using living neurons. Techniques to construct and control three-dimensional circuits have also been established. Advances in multiple electrode arrays as well as genetically encoded, optical activity sensors and transducers enabled highly specific interfaces to circuits composed of thousands of neurons. Further advances in on-chip neural circuits may lead to better understanding of the brain.

  6. 油船压力真空/断开装置适用范围探讨%Discussion of Application for Pressure/Vacuum Breaker on Oil Tanker

    Institute of Scientific and Technical Information of China (English)

    昝彬彬

    2016-01-01

    Due to the different understanding of whether the pressure /vacuum ( PV) breaker should be installed on a tanker without inert gas system , the new application range of the PV breaker is proposed based on analysis of convention requirements , class rules , cargo handling regulations and fault tree analysis of cargo tank pressure .%针对目前业内对于压力/真空断开装置( PV breaker )是否适用于未装设惰性气体系统的船舶存在理解上的差异的问题,从公约条款、各船级社规范,油船装卸货操作要求以及货舱压力故障事故树分析等方面对油船PV breaker的适用范围进行探讨,提出油船PV breaker新的适用范围.

  7. 75 FR 29784 - Petitions for Modification

    Science.gov (United States)

    2010-05-27

    ... Wire Gauge (AWG) cable; (2) all circuit breakers used to protect the No. 2 AWG trailing cables... setting of these circuit breakers will be sealed to insure that the settings on the breakers cannot be changed, and will have permanent, legible labels. Each label will identify the circuit breaker as...

  8. 48 CFR 225.7006-4 - Solicitation provision and contract clause.

    Science.gov (United States)

    2010-10-01

    ... and contract clause. (a) Use the provision at 252.225-7037, Evaluation of Offers for Air Circuit Breakers, in solicitations requiring air circuit breakers for naval vessels unless— (1) An exception... Breakers, in solicitations and contracts requiring air circuit breakers for naval vessels unless— (1)...

  9. 75 FR 41529 - Petitions for Modification

    Science.gov (United States)

    2010-07-16

    ... than 10 American Wire Gauge (AWG); (4) all circuit breakers used to protect trailing cables exceeding... breakers will be sealed or locked, and these circuit breakers will have permanent, legible labels. Each label will identify the circuit breaker as being suitable for protecting the trailing cables. This...

  10. 76 FR 22152 - Petitions for Modification of Application of Existing Mandatory Safety Standards

    Science.gov (United States)

    2011-04-20

    ... haulage unit will not be smaller than a 2 AWG; (3) all circuit breakers used to protect the 4 AWG trailing... larger than 500 AMPS. The circuit breakers will have permanent legible labels attached. The label will identify the circuit breakers as being suitable for protecting 4 AWG cables; (4) replacement breakers...

  11. Replacement Method OptimiTation of the Breakers in Substation%变电站断路器更换方法的优化

    Institute of Scientific and Technical Information of China (English)

    秦卫东; 郭锐; 苏长宝

    2011-01-01

    Along with rapid development of power technology, the old primary equipment in many substations is in the urgent needs of replacement. As a major primary equipment, the breaker plays an important role in stable operation of a substation. The traditional breaker replacement method has a time-consuming problem, affecting the power supply reliability. The breaker replacement method for 110 kV substations is optimized in this paper by using the key route method. It is proved that the optimized new method can significantly shorten the replacement time and reduce the power cut time of a transmission line, subsequently improving the stability of electric power system and the reliability of power supply.%随着电力事业的飞速发展,许多变电站安装的老式一次设备需更换。断路器作为重要的一次设备,对于变电站的稳定运行具有重要作用,但传统的更换方法存在时间长、影响供电可靠性的问题。在保证工程质量的前提下,运用关键路径法对110kV变电站断路器更换的施工方法进行了优化分析。应用实践表明,此方法可以极大地缩短工期,减少线路停电时间,有利于提高电力系统的稳定性和供电可靠性。

  12. Multi-Layer E-Textile Circuits

    Science.gov (United States)

    Dunne, Lucy E.; Bibeau, Kaila; Mulligan, Lucie; Frith, Ashton; Simon, Cory

    2012-01-01

    Stitched e-textile circuits facilitate wearable, flexible, comfortable wearable technology. However, while stitched methods of e-textile circuits are common, multi-layer circuit creation remains a challenge. Here, we present methods of stitched multi-layer circuit creation using accessible tools and techniques.

  13. 30 CFR 56.6403 - Branch circuits.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Branch circuits. 56.6403 Section 56.6403... Blasting § 56.6403 Branch circuits. (a) If electric blasting includes the use of branch circuits, each branch shall be equipped with a safety switch or equivalent method to isolate the circuits to be used....

  14. Equivalence Checking of Hierarchical Combinational Circuits

    DEFF Research Database (Denmark)

    Williams, Poul Frederick; Hulgaard, Henrik; Andersen, Henrik Reif

    1999-01-01

    This paper presents a method for verifying that two hierarchical combinational circuits implement the same Boolean functions. The key new feature of the method is its ability to exploit the modularity of circuits to reuse results obtained from one part of the circuits in other parts. We demonstra...... our method on large adder and multiplier circuits....

  15. Difference-Equation/Flow-Graph Circuit Analysis

    Science.gov (United States)

    Mcvey, I. M.

    1988-01-01

    Numerical technique enables rapid, approximate analyses of electronic circuits containing linear and nonlinear elements. Practiced in variety of computer languages on large and small computers; for circuits simple enough, programmable hand calculators used. Although some combinations of circuit elements make numerical solutions diverge, enables quick identification of divergence and correction of circuit models to make solutions converge.

  16. Comparison between four piezoelectric energy harvesting circuits

    Institute of Scientific and Technical Information of China (English)

    Jinhao QIU; Hao JIANG; Hongli JI; Kongjun ZHU

    2009-01-01

    This paper investigates and compares the efficiencies of four different interfaces for vibration-based energy harvesting systems. Among those four circuits, two circuits adopt the synchronous switching technique, in which the circuit is switched synchronously with the vibration. In this study, a simple source-less trigger circuit used to control the synchronized switch is proposed and two interface circuits of energy harvesting systems are designed based on the trigger circuit. To validate the effectiveness of the proposed circuits, an experimental system was established and the power harvested by those circuits from a vibration beam was measured. Experimental results show that the two new circuits can increase the harvested power by factors 2.6 and 7, respectively, without consuming extra power in the circuits.

  17. Using Combinational Circuits for Control Purposes

    Directory of Open Access Journals (Sweden)

    Maher A. Nabulsi

    2009-01-01

    Full Text Available Problem statement: Combinational circuits are used in computers for generating binary control decisions and for providing digital components for data processing. Approach: The use of combinational circuits and logic gates to control other circuits was discussed. Different systems that use logic gates, multiplexers, decoders and encoders to control different circuits were presented. This study presented a design and implementation of some combinational circuits such as a decoder, an encoder, a multiplexer, a bus system and read/write memory operations. Results: When we connected some types of combinational circuits to the inputs/outputs of digital circuit, these combinational circuits can help us to manage and flow a different types of control signals through a large digital circuit. Conclusion: Many combinational circuits had a good function which can be used for controlling different parts of any digital system and they produce a suitable way to transfer a control signals between different digital components of any large digital system.

  18. Instrumentation and test gear circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Instrumentation and Test Gear Circuits Manual provides diagrams, graphs, tables, and discussions of several types of practical circuits. The practical circuits covered in this book include attenuators, bridges, scope trace doublers, timebases, and digital frequency meters. Chapter 1 discusses the basic instrumentation and test gear principles. Chapter 2 deals with the design of passive attenuators, and Chapter 3 with passive and active filter circuits. The subsequent chapters tackle 'bridge' circuits, analogue and digital metering techniques and circuitry, signal and waveform generation, and p

  19. 49 CFR 236.5 - Design of control circuits on closed circuit principle.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Design of control circuits on closed circuit..., AND APPLIANCES Rules and Instructions: All Systems General § 236.5 Design of control circuits on closed circuit principle. All control circuits the functioning of which affects safety of train...

  20. 30 CFR 77.506 - Electric equipment and circuits; overload and short-circuit protection.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Electric equipment and circuits; overload and short-circuit protection. 77.506 Section 77.506 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION... circuits; overload and short-circuit protection. Automatic circuit-breaking devices or fuses of the...

  1. Introduction to lethal circuit transformations

    Science.gov (United States)

    Fišer, Petr; Schmidt, Jan

    2015-12-01

    Logic optimization is a process that takes a logic circuit description (Boolean network) as an input and tries to refine it, to reduce its size and/or depth. An ideal optimization process should be able to devise an optimum implementation of a network in a reasonable time, given any circuit structure at the input. However, there are cases where it completely fails to produce even near-optimum solutions. Such cases are typically induced by non-standard circuit structure modifications. Surprisingly enough, such deviated structures are frequently present in standard benchmark sets too. We may only wonder whether it is an intention of the benchmarks creators, or just an unlucky coincidence. Even though synthesis tools should be primarily well suited for practical circuits, there is no guarantee that, e.g., a higher-level synthesis process will not generate such unlucky structures. Here we present examples of circuit transformations that lead to failure of most of state-of-the-art logic synthesis and optimization processes, both academic and commercial, and suggest actions to mitigate the disturbing effects.

  2. Logic circuits from zero forcing.

    Science.gov (United States)

    Burgarth, Daniel; Giovannetti, Vittorio; Hogben, Leslie; Severini, Simone; Young, Michael

    We design logic circuits based on the notion of zero forcing on graphs; each gate of the circuits is a gadget in which zero forcing is performed. We show that such circuits can evaluate every monotone Boolean function. By using two vertices to encode each logical bit, we obtain universal computation. We also highlight a phenomenon of "back forcing" as a property of each function. Such a phenomenon occurs in a circuit when the input of gates which have been already used at a given time step is further modified by a computation actually performed at a later stage. Finally, we show that zero forcing can be also used to implement reversible computation. The model introduced here provides a potentially new tool in the analysis of Boolean functions, with particular attention to monotonicity. Moreover, in the light of applications of zero forcing in quantum mechanics, the link with Boolean functions may suggest a new directions in quantum control theory and in the study of engineered quantum spin systems. It is an open technical problem to verify whether there is a link between zero forcing and computation with contact circuits.

  3. Dynamical compensation in physiological circuits.

    Science.gov (United States)

    Karin, Omer; Swisa, Avital; Glaser, Benjamin; Dor, Yuval; Alon, Uri

    2016-11-08

    Biological systems can maintain constant steady-state output despite variation in biochemical parameters, a property known as exact adaptation. Exact adaptation is achieved using integral feedback, an engineering strategy that ensures that the output of a system robustly tracks its desired value. However, it is unclear how physiological circuits also keep their output dynamics precise-including the amplitude and response time to a changing input. Such robustness is crucial for endocrine and neuronal homeostatic circuits because they need to provide a precise dynamic response in the face of wide variation in the physiological parameters of their target tissues; how such circuits compensate their dynamics for unavoidable natural fluctuations in parameters is unknown. Here, we present a design principle that provides the desired robustness, which we call dynamical compensation (DC). We present a class of circuits that show DC by means of a nonlinear feedback loop in which the regulated variable controls the functional mass of the controlling endocrine or neuronal tissue. This mechanism applies to the control of blood glucose by insulin and explains several experimental observations on insulin resistance. We provide evidence that this mechanism may also explain compensation and organ size control in other physiological circuits.

  4. Nuclear sensor signal processing circuit

    Science.gov (United States)

    Kallenbach, Gene A.; Noda, Frank T.; Mitchell, Dean J.; Etzkin, Joshua L.

    2007-02-20

    An apparatus and method are disclosed for a compact and temperature-insensitive nuclear sensor that can be calibrated with a non-hazardous radioactive sample. The nuclear sensor includes a gamma ray sensor that generates tail pulses from radioactive samples. An analog conditioning circuit conditions the tail-pulse signals from the gamma ray sensor, and a tail-pulse simulator circuit generates a plurality of simulated tail-pulse signals. A computer system processes the tail pulses from the gamma ray sensor and the simulated tail pulses from the tail-pulse simulator circuit. The nuclear sensor is calibrated under the control of the computer. The offset is adjusted using the simulated tail pulses. Since the offset is set to zero or near zero, the sensor gain can be adjusted with a non-hazardous radioactive source such as, for example, naturally occurring radiation and potassium chloride.

  5. Chua's Circuit: Control and Synchronization

    Science.gov (United States)

    Irimiciuc, Stefan-Andrei; Vasilovici, Ovidiu; Dimitriu, Dan-Gheorghe

    Chaos-based data encryption is one of the most reliable methods used in secure communications. This implies a good control of a chaotic system and a good synchronization between the involved systems. Here, experimental results are shown on the control and synchronization of Chua's circuits. The control of the chaotic circuit was achieved by using the switching method. The influence of the control signal characteristics (amplitude, frequency and shape) on the system's states was also investigated. The synchronization of two similar chaotic circuits was studied, emphasizing the importance of the chaotic state characteristics of the Master system in respect to those of Slave system. It was shown that the synchronization does not depend on the chaotic state type, neither on the dimension (x, y or z) used for synchronization.

  6. Additive Manufacturing of Hybrid Circuits

    Science.gov (United States)

    Sarobol, Pylin; Cook, Adam; Clem, Paul G.; Keicher, David; Hirschfeld, Deidre; Hall, Aaron C.; Bell, Nelson S.

    2016-07-01

    There is a rising interest in developing functional electronics using additively manufactured components. Considerations in materials selection and pathways to forming hybrid circuits and devices must demonstrate useful electronic function; must enable integration; and must complement the complex shape, low cost, high volume, and high functionality of structural but generally electronically passive additively manufactured components. This article reviews several emerging technologies being used in industry and research/development to provide integration advantages of fabricating multilayer hybrid circuits or devices. First, we review a maskless, noncontact, direct write (DW) technology that excels in the deposition of metallic colloid inks for electrical interconnects. Second, we review a complementary technology, aerosol deposition (AD), which excels in the deposition of metallic and ceramic powder as consolidated, thick conformal coatings and is additionally patternable through masking. Finally, we show examples of hybrid circuits/devices integrated beyond 2-D planes, using combinations of DW or AD processes and conventional, established processes.

  7. Vertically Integrated Circuits at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Deptuch, Grzegorz; Demarteau, Marcel; Hoff, James; Lipton, Ronald; Shenai, Alpana; Trimpl, Marcel; Yarema, Raymond; Zimmerman, Tom; /Fermilab

    2009-01-01

    The exploration of the vertically integrated circuits, also commonly known as 3D-IC technology, for applications in radiation detection started at Fermilab in 2006. This paper examines the opportunities that vertical integration offers by looking at various 3D designs that have been completed by Fermilab. The emphasis is on opportunities that are presented by through silicon vias (TSV), wafer and circuit thinning and finally fusion bonding techniques to replace conventional bump bonding. Early work by Fermilab has led to an international consortium for the development of 3D-IC circuits for High Energy Physics. The consortium has submitted over 25 different designs for the Fermilab organized MPW run organized for the first time.

  8. Analysis on Relativity Between Load Dynamics and Three-phase Short-circuit Current of Receiving-end Power System%受端电网负荷动态特性与三相短路电流相关性分析

    Institute of Scientific and Technical Information of China (English)

    曹炜; 王伟; 刘蓓; 王永生; 段开元; 丁北平

    2011-01-01

    对某实际受端电力系统进行了机电暂态仿真,表明当受端系统联系紧密时,负荷动态特性对三相短路电流周期分量的初始有效值及其在50 ms内的衰减数值影响较大,对该电网某次三相短路故障录波数据的波形分解结果也支持上述观点.仿真还表明,由于三相短路电流存在衰减,传统的不考虑负荷动态特性时求出的短路电流周期分量初始有效值仍可用来检验断路器的开断能力,但不宜用来检验断路器的动稳定.%Mechanic-electric simulation of a real receiving-end power system shows that the load dynamics have a significant impact on the symmetrical three-phase short-circuit current within 50 ms after short-circuit. This is supported by the fault-recording data of a power grid accident. The simulation data and the fault-recording data both indicate that the result from the traditional practical short-circuit calculation can be used to check the interrupting capacity of the circuit breaker, but can not be used to check the stress intensity of the circuit breaker.

  9. Integrated circuits for multimedia applications

    DEFF Research Database (Denmark)

    Vandi, Luca

    2007-01-01

    This work presents several key aspects in the design of RF integrated circuits for portable multimedia devices. One chapter is dedicated to the application of negative-feedback topologies to receiver frontends. A novel feedback technique suitable for common multiplier-based mixers is described......, and it is applied to a broad-band dual-loop receiver architecture in order to boost the linearity performances of the stage. A simplified noise- and linearity analysis of the circuit is derived, and a comparison is provided with a more traditional dual-loop topology (a broad-band stage based on shunt...

  10. Fermionic models with superconducting circuits

    Energy Technology Data Exchange (ETDEWEB)

    Las Heras, Urtzi; Garcia-Alvarez, Laura; Mezzacapo, Antonio; Lamata, Lucas [University of the Basque Country UPV/EHU, Department of Physical Chemistry, Bilbao (Spain); Solano, Enrique [University of the Basque Country UPV/EHU, Department of Physical Chemistry, Bilbao (Spain); IKERBASQUE, Basque Foundation for Science, Bilbao (Spain)

    2015-12-01

    We propose a method for the efficient quantum simulation of fermionic systems with superconducting circuits. It consists in the suitable use of Jordan-Wigner mapping, Trotter decomposition, and multiqubit gates, be with the use of a quantum bus or direct capacitive couplings. We apply our method to the paradigmatic cases of 1D and 2D Fermi-Hubbard models, involving couplings with nearest and next-nearest neighbours. Furthermore, we propose an optimal architecture for this model and discuss the benchmarking of the simulations in realistic circuit quantum electrodynamics setups. (orig.)

  11. Circuit modeling for electromagnetic compatibility

    CERN Document Server

    Darney, Ian B

    2013-01-01

    Very simply, electromagnetic interference (EMI) costs money, reduces profits, and generally wreaks havoc for circuit designers in all industries. This book shows how the analytic tools of circuit theory can be used to simulate the coupling of interference into, and out of, any signal link in the system being reviewed. The technique is simple, systematic and accurate. It enables the design of any equipment to be tailored to meet EMC requirements. Every electronic system consists of a number of functional modules interconnected by signal links and power supply lines. Electromagnetic interference

  12. Simplified design of filter circuits

    CERN Document Server

    Lenk, John

    1999-01-01

    Simplified Design of Filter Circuits, the eighth book in this popular series, is a step-by-step guide to designing filters using off-the-shelf ICs. The book starts with the basic operating principles of filters and common applications, then moves on to describe how to design circuits by using and modifying chips available on the market today. Lenk's emphasis is on practical, simplified approaches to solving design problems.Contains practical designs using off-the-shelf ICsStraightforward, no-nonsense approachHighly illustrated with manufacturer's data sheets

  13. Embedded systems circuits and programming

    CERN Document Server

    Sanchez, Julio

    2012-01-01

    During the development of an engineered product, developers often need to create an embedded system--a prototype--that demonstrates the operation/function of the device and proves its viability. Offering practical tools for the development and prototyping phases, Embedded Systems Circuits and Programming provides a tutorial on microcontroller programming and the basics of embedded design. The book focuses on several development tools and resources: Standard and off-the-shelf components, such as input/output devices, integrated circuits, motors, and programmable microcontrollers The implementat

  14. Endogenous money, circuits and financialization

    OpenAIRE

    Malcolm Sawyer

    2013-01-01

    This paper locates the endogenous money approach in a circuitist framework. It argues for the significance of the credit creation process for the evolution of the economy and the absence of any notion of ‘neutrality of money’. Clearing banks are distinguished from other financial institutions as the providers of initial finance in a circuit whereas other financial institutions operate in a final finance circuit. Financialization is here viewed in terms of the growth of financial assets an...

  15. Circuit, Thermal and Cost Characteristics of Impulse Magnetizing Circuits

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper describes the development of circuit, thermal and cost model for a capacitor discharge impulse megnetizer and compares simulations to measurements from an actual system. We used a cost structure consisting of five major subsystems for cost modeling. Especially, we estimated the potential for cost reductions impulse magnetizer as a function of time using the learning curve.

  16. An Approach to Simplify Reversible Logic Circuits

    Directory of Open Access Journals (Sweden)

    Pabitra Roy

    2012-09-01

    Full Text Available Energy loss is one of the major problems in traditional irreversible circuits. For every bit of information loss kTln2 joules of heat is lost. In order to reduce the energy loss the concept of reversible logic circuits are introduced. Here we have described an algorithm for simplifying the reversible logic circuit and hence reduction of circuit cost and energy. The algorithm considers sub_circuit with respect to their number of lines and contiguous gates. The resulting sub_circuits are re-synthesized with smaller equivalent implementation. The process continues until circuit cost reaches good enough for Application or until a given computation budget has been exhausted. The circuit is constructed by NOT, CNOT and Toffoli gates only. By applying the algorithm and using the equivalent implementation we will get significant reduction of circuit cost and hence energy.

  17. Relaxation Based Electrical Simulation for VLSI Circuits

    Directory of Open Access Journals (Sweden)

    S. Rajkumar

    2012-06-01

    Full Text Available Electrical circuit simulation was one of the first CAD tools developed for IC design. The conventional circuit simulators like SPICE and ASTAP were designed initially for the cost effective analysis of circuits containing a few hundred transistors or less. A number of approaches have been used to improve the performances of congenital circuit simulators for the analysis of large circuits. Thereafter relaxation methods was proposed to provide more accurate waveforms than standard circuit simulators with up to two orders of magnitude speed improvement for large circuits. In this paper we have tried to highlights recently used waveform and point relaxation techniques for simulation of VLSI circuits. We also propose a simple parallelization technique and experimentally demonstrate that we can solve digital circuits with tens of million transistors in a few hours.

  18. Retropath: automated pipeline for embedded metabolic circuits.

    Science.gov (United States)

    Carbonell, Pablo; Parutto, Pierre; Baudier, Claire; Junot, Christophe; Faulon, Jean-Loup

    2014-08-15

    Metabolic circuits are a promising alternative to other conventional genetic circuits as modular parts implementing functionalities required for synthetic biology applications. To date, metabolic design has been mainly focused on production circuits. Emergent applications such as smart therapeutics, however, require circuits that enable sensing and regulation. Here, we present RetroPath, an automated pipeline for embedded metabolic circuits that explores the circuit design space from a given set of specifications and selects the best circuits to implement based on desired constraints. Synthetic biology circuits embedded in a chassis organism that are capable of controlling the production, processing, sensing, and the release of specific molecules were enumerated in the metabolic space through a standard procedure. In that way, design and implementation of applications such as therapeutic circuits that autonomously diagnose and treat disease, are enabled, and their optimization is streamlined.

  19. Digital circuit boards mach 1 GHz

    CERN Document Server

    Morrison, Ralph

    2012-01-01

    A unique, practical approach to the design of high-speed digital circuit boards The demand for ever-faster digital circuit designs is beginning to render the circuit theory used by engineers ineffective. Digital Circuit Boards presents an alternative to the circuit theory approach, emphasizing energy flow rather than just signal interconnection to explain logic circuit behavior. The book shows how treating design in terms of transmission lines will ensure that the logic will function, addressing both storage and movement of electrical energy on these lines. It cove

  20. Advanced circuit simulation using Multisim workbench

    CERN Document Server

    Báez-López, David; Cervantes-Villagómez, Ofelia Delfina

    2012-01-01

    Multisim is now the de facto standard for circuit simulation. It is a SPICE-based circuit simulator which combines analog, discrete-time, and mixed-mode circuits. In addition, it is the only simulator which incorporates microcontroller simulation in the same environment. It also includes a tool for printed circuit board design.Advanced Circuit Simulation Using Multisim Workbench is a companion book to Circuit Analysis Using Multisim, published by Morgan & Claypool in 2011. This new book covers advanced analyses and the creation of models and subcircuits. It also includes coverage of transmissi