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Sample records for adjustable speed drive

  1. Adjustable Speed Drives and Power Quality

    Davari, Pooya; Yang, Yongheng; Zare, Firuz;

    2016-01-01

    This paper provides an overview and proposes cost-effective and efficient opportunities in improving power quality in Adjustable Speed Drive (ASD) systems. In particular, an Electronic Inductor (EI) technique has been used in single drives to overcome the existing challenges in conventional...

  2. Adjustable Speed Drives - Future Challenges and Applications

    Blaabjerg, Frede; Thoegersen, Paul

    2004-01-01

    The main trends within Adjustable Drives in industrial and appliance applications for the next decade are discussed based on the newest developments seen on the market and a few historical trends. Different drive configurations are presented and the general demands to adjustable speed drives are...... specified. Further on power architectures and motor types are discussed in a short term and long-term view. Possible drivers of the future development are identified, and the concept of an ?Electronic Motor? is discussed. A number of applications are presented where variable speed is attractive....

  3. Retrofitting adjustable speed drives for large induction motors

    Adjustable speed drives (ASDs) are used in many power plants to control process flow by varying the speed of synchronous and induction motors. In applications where the flow requirements vary significantly, ASDs reduce energy and maintenance requirements when compared with drag valves, dampers or other methods to control flow. Until recently, high horsepower ASDs were not available for induction motors. However, advances in power electronics technology have demonstrated the reliability and cost effectiveness of ASDs for large horsepower induction motors. Emphasis on reducing operation and maintenance costs and increasing the capacity factor of nuclear power plants has led some utilities to consider replacing flow control devices in systems powered by large induction motors with ASDs. ASDs provide a high degree of reliability and significant energy savings in situations where full flow operation is not needed for a substantial part of the time. This paper describes the basic adjustable speed drive technologies available for large induction motor applications, ASD operating experience and retrofitting ASDs to replace the existing GE Boiling Water Reactor recirculation flow control system

  4. Adjustable speed drives: Applications and R&D needs

    Stefanovic, V.R.

    1995-09-01

    The largest opportunity for the growth of adjustable speed drives (ASDs) during the next 5-6 years is in pump, fan and compressor (PFC) applications where a constant, fixed speed operation is converted to adjustable speed in order to realize energy savings. Inverter supplied induction motors are and will continue to be predominately used in these applications. Over the long term (10-15 years), the greatest ASD growth is expected in large volume consumer applications: first in hybrid electric vehicles (EVs) and in residential heating, ventilation and air-conditioning (HVAC). Both induction and a variety of AC Permanent Magnet motors are expected to be the dominant technology in this new field. The traditional ASD applications in industries which require adjustable speed (such as machine tools, robotics, steel rolling, extruders, paper mill finishing lines, etc.) offer a relatively limited potential for above average ASD growth since most of these applications have already converted to electronic speed control. As a result, ASD growth in this sector will essentially track the growth of the corresponding industries. If realized, both short and long term ASD growth opportunities will result in significant advancements of ASD technology, which will then substantially affect all other, more fragmented, ASD applications. In fact, any single large volume ASD application will serve as a catalyst for improving ASD characteristics in all other ASD applications with the same voltage rating. ASD cost and reliability (defined in the context of application compatibility) are the two most important factors which will determine whether the ASD growth opportunities are realized. Conversely, any technological improvement which carries a cost increase will be restricted to niche applications, at best. Consequently, future R & D efforts should be directed to secure reduction in ASD cost and improvement in ASD reliability. A specific action plan is outlined in this report.

  5. ANALYSIS OF EFFECTS OF VECTOR CONTROL ON TOTAL CURRENT HARMONIC DISTORTION OF ADJUSTABLE SPEED AC DRIVE

    KARTIK TAMVADA

    2012-04-01

    Full Text Available Adjustable speed drive (ASD is becoming a significant load component for power distribution. It involves the use of an Induction motor (IM. This paper involves modeling and control of an Induction motor andinvestigates its effects on the total current harmonic distortion of the adjustable speed ac drives. The simulation was carried out with the aid of the Simulink toolbox available in Matlab. It is seen that with Vector control the THDi of the drive reduces considerably.

  6. ANALYSIS OF EFFECTS OF VECTOR CONTROL ON TOTAL CURRENT HARMONIC DISTORTION OF ADJUSTABLE SPEED AC DRIVE

    KARTIK TAMVADA; R.KAMESWARA RAO

    2012-01-01

    Adjustable speed drive (ASD) is becoming a significant load component for power distribution. It involves the use of an Induction motor (IM). This paper involves modeling and control of an Induction motor andinvestigates its effects on the total current harmonic distortion of the adjustable speed ac drives. The simulation was carried out with the aid of the Simulink toolbox available in Matlab. It is seen that with Vector control the THDi of the drive reduces considerably.

  7. Minimize Adverse Motor and Adjustable Speed Drive Interactions - Motor Tip Sheet #15

    None

    2008-07-01

    Electronic adjustable speed drives (ASDs) are an extremely efficient and valuable asset to motor systems. They allow precise process control and provide energy savings within systems that do not need to continuously operate at full output.

  8. FLC based adjustable speed drives for power quality enhancement

    Sukumar Darly

    2010-01-01

    Full Text Available This study describes a new approach based on fuzzy algorithm to suppress the current harmonic contents in the output of an inverter. Inverter system using fuzzy controllers provide ride-through capability during voltage sags, reduces harmonics, improves power factor and high reliability, less electromagnetic interference noise, low common mode noise and extends output voltage range. A feasible test is implemented by building a model of three-phase impedance source inverter, which is designed and controlled on the basis of proposed considerations. It is verified from the practical point of view that these new approaches are more effective and acceptable to minimize the harmonic distortion and improves the quality of power. Due to the complex algorithm, their realization often calls for a compromise between cost and performance. The proposed optimizing strategies may be applied in variable-frequency dc-ac inverters, UPSs, and ac drives.

  9. LC Filter Design for Wide Band Gap Device Based Adjustable Speed Drives

    Vadstrup, Casper; Wang, Xiongfei; Blaabjerg, Frede

    This paper presents a simple design procedure for LC filters used in wide band gap device based adjustable speed drives. Wide band gap devices offer fast turn-on and turn-off times, thus producing high dV/dt into the motor terminals. The high dV/dt can be harmful for the motor windings and bearings...

  10. Adjustable Speed Drive Project for Teaching a Servo Systems Course Laboratory

    Rodriguez-Resendiz, J.; Herrera-Ruiz, G.; Rivas-Araiza, E. A.

    2011-01-01

    This paper describes an adjustable speed drive for a three-phase motor, which has been implemented as a design for a servo system laboratory course in an engineering curriculum. The platform is controlled and analyzed in a LabVIEW environment and run on a PC. Theory is introduced in order to show the sensorless algorithms. These are computed by…

  11. Adjustable Speed Drives in the Next Decade. Future Steps in Industry and Academia

    Thøgersen, Paul; Blaabjerg, Frede

    2004-01-01

    The main trends for the next decade within the multi-disciplinarian field of adjustable speed drives are discussed, and a number of topics are especially addressed in this paper. The topics include market development over the last decade, historical development in power converter volume and weigh......, future drive demands, power converter architecture, interfacing to the grid, motor types, and control principles. Furthermore, some of the possibilities and trends related to decentral ?intelligence? and Internet connection are discussed.......The main trends for the next decade within the multi-disciplinarian field of adjustable speed drives are discussed, and a number of topics are especially addressed in this paper. The topics include market development over the last decade, historical development in power converter volume and weight...

  12. Adjustable-Speed Single-Phase IM Drive with Reduced Number of Switches

    Chomát, Miroslav; Lipo, T. A.

    Chicago : IEEE Industry Applications Society IAS, 2001, s. 1-6. ISBN 0-7803-7114-3. [IEEE Industry Applications Conference - Annual Meeting /36./. Chicago (US), 30.09.2001-04.10.2001] R&D Projects: GA AV ČR IAB2057903 Grant ostatní: NSFA(US) 9820434 Keywords : adjustable-speed drive * single-phase induction machine Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  13. Adjustable-Speed Drive with Single-Phase Induction Machine for HVAC Applications

    Chomát, Miroslav; Lipo, T. A.

    Vancouver : University of British Columbia, 2001, s. 1-6. ISBN 0-7803-7069-4. [Power Electronics Specialists Conference PESC 2001 /32./. Vancouver (CA), 17.06.2001-22.06.2001] R&D Projects: GA MŠk ME 332 Grant ostatní: NSFA(US) 9820434 Keywords : adjustable-speed drive * single-phase induction machine Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  14. IMPROVED PERFORMANCE OF AN ADJUSTABLE SPEED DRIVES DURING VOLTAGE SAG CONDITION

    S.S.DESWAL

    2010-06-01

    Full Text Available Voltage sags normally do not cause equipment damage but can easily disrupt the operation of sensitive loads such as electronic Adjustable Speed Drives (ASD’s. Voltage sags cause a momentary decrease in DC-link voltage triggering an under voltage trip leading to nuisance tripping of adjustable speed drives (ASD’s employed in continuous-process industries which contributes to loss in revenue. A practical ride-through scheme for an adjustable speed drives based on supercapacitor during voltage sag has been presented in this paper. The supercapacitor maintains the ASD dc bus voltage under voltage sag condition. Energy storage module is connected to support the DC-link voltage during power system faults. The performance of ASD’s under normal and power system faults is first simulated in MATLab Simulink and then experimentally verified. The Data AcQuisition boards (DAQ of National Instruments along with LabVIEW software have been used torecord the observed waveforms.

  15. Commutation effect of Adjustable Speed Drives due to installation of active harmonic filters

    Asiminoaei, Lucian; Kalaschnikow, Sergej; Hansen, Steffan;

    2011-01-01

    The success of designing an industrial installation with Active Filters depends on how precise the load profile of the application is known, because this determines the amount of harmonic currents to be compensated. However, once the Active Filter is added to the installation, the harmonic currents...... may increase due to changes in the commutation behavior of diode rectifier converters. The change of natural commutation determines higher harmonics currents of the diode rectifiers and therefore higher harmonic loading of the Active Filter in the installation. This paper presents a method to estimate...... the commutation behavior of Adjustable Speed Drives when their harmonic currents are compensated by a Shunt Active Filter. The method is formulated as an analytical computation algorithm verified by simulations. Further on the method is implemented in a Harmonic Calculation Toolbox which facilitates...

  16. The Use of Active Elements to Reduce the Size and Weight of Passive Components in Adjustable Speed Drives

    Maheshwari, Ram Krishan

    shaft voltage, the common mode voltage, the conducted emissions, and the efficiency of the two systems are compared since they are major factors which affect the size of the passive components in the drives. Although the three-level inverter requires higher number of active components as compared to the......Adjustable speed drives are considered as workhorse of industry due to various applications in different kind of industries. According to a market survey, low voltage drives are most profitable in the drive industries. The drive consists of a machine and a converter, which processes grid power and...... converts into usable power for the machine. The converter consists of active and passive components. The size, weight, and volume of the drive are decided by the passive components since they typically contribute to 75% of the weight and volume of the drive. Most popular topology for the low voltage drive...

  17. Evaluation of the Ride-Through Capability of an Active-Front-End Adjustable Speed Drive under Real Grid Conditions

    Liserre, Marco; Klumpner, Christian; Blaabjerg, Frede;

    2004-01-01

    Better quality of the input currents, unity power factor and regenerative capability are not the only benefits of equipping an Adjustable Speed Drive (ASD) with an active front-end-stage. Controlling the power inflow may enable also the reduction of the dc-link energy storage, which will then lead...

  18. Analysis of cutting-edge techniques in the high voltage and high power adjustable speed drive systems

    2009-01-01

    The high voltage and high power adjustable speed drive (ASD) system is one of the most attractive fields in power electronics, and it is also a very crucial technique for energy saving and emission reduction. This paper discussed and analyzed the main cutting-edge knowledge and issues in the process of exploiting the high voltage and high power ASD system.

  19. Shunt active filter algorithms for a three phase system fed to adjustable speed drive

    Sujatha.CH; Sravanthi.Kusam; Dr. K.Chandra shek

    2011-01-01

    This paper presents the simulation of Shunt Active Power filter by using two different control schemes, Indirect current control technique and Synchronous detection technique by using ANN. These two control techniques are working under both balanced and unbalanced three phase voltage source conditions and it is feeding to aadjustable speed drive the torque speed characteristics of a motor is presented. Indirect current control technique is implemented under dynamic load condition and load bal...

  20. Limitation of Adjustable-Speed Drive Operation by Unbalanced Voltage Supply

    Chomát, Miroslav; Schreier, Luděk; Bendl, Jiří

    Piscataway : IEEE, 2008, s. 1-6. ISBN 978-1-4244-1736-0. [International Conference on Electrical Machines - ICEM 2008 /18./. Vilamoura (PT), 06.09.2008-09.09.2008] R&D Projects: GA ČR GA102/06/0215 Institutional research plan: CEZ:AV0Z20570509 Keywords : unbalanced voltage supply * DC-link voltage pulsations * variable-speed drive Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering www.apdee.org

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

    Davari, Pooya; Yang, Yongheng; Zare, Firuz;

    2016-01-01

    Electronic Inductor (EI) techniques are promising approaches for improving the grid-side current quality, and they are suitable for motor drive applications. In this paper, different EI topologies are investigated from the efficiency perspective, including the effect of employing Silicon Carbide...... (SiC) power devices. Moreover, the influence of partial loading on component sizing in Adjustable Speed Drives (ASDs) is studied. Finally the analytical loss modelling of power switches is utilized for efficiency measurement. The theoretical analyses are verified by experimental benchmarking in an ASD...

  2. Buck-Boost Control of Four Quadrant Chopper using Symmetrical Impedance Network for Adjustable Speed Drive

    Saswati Swapna Dash; Byamakesh Nayak

    2015-01-01

    This paper proposes buck-boost capabilities of four quadrant chopper for wide range speed control of DC motor drives using symmetrical impedance network called Z-source network. By controlling the shoot through duty ratio from 0 to 0.5 and non-shoot through techniques, the Z-source four quadrant choppers can produce any desired DC voltage across the DC motor. The switching patterns for both buck and boost operations are presented to achieve four modes of operation of DC motor. As a result, th...

  3. Passive wide spectrum harmonic filter for adjustable speed drives in oil and gas industry

    Al Jaafari, Khaled Ali

    Non-linear loads such as variable speed drives constitute the bulky load of oil and gas industry power systems. They are widely used in driving induction and permanent magnet motors for variable speed applications. That is because variable speed drives provide high static and dynamic performance. Moreover, they are known of their high energy efficiency and high motion quality, and high starting torque. However, these non-linear loads are main sources of current and voltage harmonics and lower the quality of electric power system. In fact, it is the six-pulse and twelve-pulse diode and thyristor rectifiers that spoil the AC power line with the dominant harmonics (5th, 7th, 11th). They provide DC voltage to the inverter of the variable speed drives. Typical problems that arise from these harmonics are Harmonic resonances', harmonic losses, interference with electronic equipment, and line voltage distortion at the Point of Common Coupling (PCC). Thus, it is necessary to find efficient, reliable, and economical harmonic filters. The passive filters have definite advantage over active filters in terms of components count, cost and reliability. Reliability and maintenance is a serious issue in drilling rigs which are located in offshore and onshore with extreme operating conditions. Passive filters are tuned to eliminate a certain frequency and therefore there is a need to equip the system with more than one passive filter to eliminate all unwanted frequencies. An alternative solution is Wide Spectrum Harmonic passive filter. The wide spectrum harmonic filters are becoming increasingly popular in these applications and found to overcome some of the limitations of conventional tuned passive filter. The most important feature of wide spectrum harmonic passive filters is that only one capacitor is required to filter a wide range of harmonics. Wide spectrum filter is essentially a low-pass filter for the harmonic at fundamental frequency. It can also be considered as a

  4. Buck-Boost Control of Four Quadrant Chopper using Symmetrical Impedance Network for Adjustable Speed Drive

    Saswati Swapna Dash

    2015-02-01

    Full Text Available This paper proposes buck-boost capabilities of four quadrant chopper for wide range speed control of DC motor drives using symmetrical impedance network called Z-source network. By controlling the shoot through duty ratio from 0 to 0.5 and non-shoot through techniques, the Z-source four quadrant choppers can produce any desired DC voltage across the DC motor. The switching patterns for both buck and boost operations are presented to achieve four modes of operation of DC motor. As a result, the proposed model will have ride through capability during voltage sags, manage during voltage swells, used in any types of DC voltage sources such as fuel cell and solar cell and improve the reliability by reducing EMI noise. Analysis and simulation results are presented to demonstrate these new findings.

  5. Adjustable-Speed Single-Phase IM Drive with Reduced Number of Switches

    Chomát, Miroslav; Lipo, T. A.

    2003-01-01

    Roč. 39, č. 3 (2003), s. 819-825. ISSN 0093-9994 R&D Projects: GA ČR GA102/02/0554 Grant ostatní: National Science Foundation(US) GA9820434 Institutional research plan: CEZ:AV0Z2057903 Keywords : AC motor drives * converters * induction motor drives Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.783, year: 2003

  6. DUAL THREE-PHASE ADJUSTABLE SPEED DRIVE WITH SYNCHRONIZED SPACE-VECTOR MODULATION

    Oleschuk V.I.

    2008-04-01

    Full Text Available Split-phase symmetrical motor drive on the base of two voltage source inverters, controlled by algorithms of synchronized pulse width modulation (PWM, has been investigated. Simulation results are presented for dual three-phase power conversion systems with continuous, discontinuous and combined versions of synchronized PWM.

  7. DUAL THREE-PHASE ADJUSTABLE SPEED DRIVE WITH SYNCHRONIZED SPACE-VECTOR MODULATION

    Oleschuk V.I.; Prudeak R.; Sizov A.S.; Iaroshenco E.M.

    2008-01-01

    Split-phase symmetrical motor drive on the base of two voltage source inverters, controlled by algorithms of synchronized pulse width modulation (PWM), has been investigated. Simulation results are presented for dual three-phase power conversion systems with continuous, discontinuous and combined versions of synchronized PWM.

  8. Feedforward Synchronised PWM for Adjustable Speed AC Drives with Different Control Modes

    Oleschuk, Valentin; Blaabjerg, Frede; Jensen, Flemming Buus

    2002-01-01

    This paper presents a novel method of direct synchronised pulswidth modulation (PWM) for three-phase voltage source inverters, feeding induction motors with different control regimes. It is based on the universal algorithm with either simplified algebraic or accurate trigonometric control functions......, with vector approached for determination of the pulse patterns, with vector approach for determination of the pulse patterns. Different control modes of the drive system with synchronised PWM, including standard scalar V/F control, and also V2/F = constant and V/F2 = constant control regimes, have been...... analysed in the paper. Simulations give the behaviour of the PWM techniques proposed. Both continuous and discontinuous schemes of synchronised PWM, applied for the corresponding control regime, have been analysed and compared....

  9. Possibilities of increased power output from existing generator plants. Feasible changes of existing generators. New technology, ASD (Adjustable Speed Drives); Muligheter for oekt effekt fra eksisterende generatoranlegg. Mulige endringer av bestaaende generatorer. Ny teknologi, ASD (Adustable Speed Drives)

    Elstroem, A.

    1996-12-31

    The present paper relates to the increase of power output from existing generator plants in Norway by new operation profiles. The paper focuses on the consequences of increasing the power turnover and production with a particular attention to the generator itself. In addition, some of the possibilities on the use of an ASD (Adjustable Speed Drives) installation are elucidated, which is a concept on regulating the number of revolutions within small limits by synchronous rotation. According to the author, the power output of generator increases between 10 to 30%

  10. Police enforcement and driving speed.

    2008-01-01

    Speed limits are violated frequently in the Netherlands. As speed is an important factor in road crashes, the surveillance of driving speeds is one of the spearheads in the policy plans of the Dutch police. Different methods of speed enforcement have proved to be effective in reducing speed and cras

  11. Motor Integrated Variable Speed Drives

    Singh, Yash Veer

    A new trend in the variable speed drives (VSDs) is to develop fully integrated systems, which lead to low-cost products with shorter design cycles. Motor Integrated design of VSDs will reduce cable length to connect drive with machine windings and installation time for end user. The electric drives...... converter losses and its size so it can fit inside the motor housing. Weight and volume of a filter inductor has to come down drastically to make it a suitable power converter for motor integrated variable speed drives. Introduction of active power electronic switches can ensure very high performance and...

  12. Adjustable drives boost nuclear plant reliability

    A new reactor recirculation control (RRC) adjustable-speed drive (ASD) and digital control system at the Washington Nuclear Plant 2 (WNP-2), Hanford, Wash., has improved plant reliability. Installed this year, the system also will lower plant maintenance costs and reduce personnel radiation doses during maintenance, since the new system has less equipment in high-radiation areas than its predecessor. Advances in power electronics have improved the reliability of adjustable-speed drives for large induction motors. Large ASDs have been used in gas, oil, and coal-fired plants since around 1984. Plants where these systems are installed have realized energy savings and operational improvements in precisely controlling process flow. They also have reduced motor maintenance by slowing the motors when full-power operation is not needed. WNP-2 is the first nuclear utility with a boiling-water reactor to change to digitally controlled reactor recirculation pumps. The new RRC system provides improved flow control and maneuverability, when operating the nuclear reactor at reduced power levels. It controls coolant flow through the reactor core to control power during normal operation. There are two pumps rated at 47,200 gallons per minute (gpm). Each is driven by a vertical, totally enclosed, air/water-cooled, three-phase induction motor. The motor is rated at 8,900 horsepower (hp) and 1,782 revolutions per minute (rpm) and is operated from a 6,600-volt, 60-hertz (Hz) electrical power supply. THe ASD and digital control system replaced a hydraulically operated flow control valve and analog control system for throttling pump output. The replacement also resulted in removing the low-frequency motor generator set used for startup and slow-speed operation. The flow control valve system required a shift from low to high frequency at minimum flow control valve position to prevent excess reactor power conditions from forming during pump shift. 6 refs., 2 figs

  13. Robust Non-Linear Direct Torque and Flux Control of Adjustable Speed Sensorless PMSM Drive Based on SVM Using a PI Predictive Controller

    F. Naceri

    2010-01-01

    Full Text Available This paper presents a new sensorless direct torque control method for voltage inverter – fed PMSM. The control methodis used a modified Direct Torque Control scheme with constant inverter switching frequency using Space Vector Modulation(DTC-SVM. The variation of stator and rotor resistance due to changes in temperature or frequency deteriorates theperformance of DTC-SVM controller by introducing errors in the estimated flux linkage and the electromagnetic torque.As a result, this approach will not be suitable for high power drives such as those used in tractions, as they require goodtorque control performance at considerably lower frequency. A novel stator resistance estimator is proposed. The estimationmethod is implemented using the Extended Kalman Filter. Finally extensive simulation results are presented to validate theproposed technique. The system is tested at different speeds and a very satisfactory performance has been achieved.

  14. Speed of adjustment: Evidence from Borsa Istanbul

    Emrah Arioglu

    2014-06-01

    Full Text Available In this study, we investigate the speed of adjustment for leverage ratios of firms listed on Borsa Istanbul, in order to investigate the prediction of the trade-off theory, regarding capital structure rebalancing. For this purpose, we estimate the speed of adjustment by using Generalized Method of Moments system estimation technique. The results of this estimation suggest the speed of adjustment as approximately 29%. This significant speed of adjustment is consistent with the prediction of trade-off theory, which suggests that firms follow target capital structures and when the firms' leverage ratios deviate from these targets; they make financial decisions with the goal of closing the gap between the previous year's leverage and target leverage of the current period.

  15. Electric motor drive unit, especially adjustment drive for vehicles

    Litterst, P.

    1980-05-29

    An electric motor drive unit, particularly an adjustment drive for vehicles with at least two parallel drive shafts is described, which is compact and saves space, and whose manufacturing costs are low compared with those of well-known drive units of this type. The drive unit contains a suitable number of magnet systems, preferably permanent magnet systems, whose pole axes are spaced and run parallel. The two pole magnet systems have diametrically opposite shell-shaped segments, to which the poles are fixed. In at least one magnet system the two segments are connected by diametrically opposite flat walls parallel to the pole axes to form a single magnetic circuit pole housing. The segments of at least one other magnet system are arranged on this pole housing so that one of these flat walls is a magnetically conducting, connecting component of the magnetic circuit of the other magnet system.

  16. Speed of Adjustment in Cointegrated Systems

    Fanelli, Luca; Paruolo, Paolo

    2007-01-01

    This paper considers the speed of adjustment to long-run equilibria, in the context of cointegrated Vector Autoregressive Processes (VAR). We discuss the definition of multivariate p-lives for any indicator of predictive ability, concentrating on cumulated interim multipliers which converge to impact factor for increasing forecasting horizon. Interim multipliers are related to autoregressive Granger-causality coefficients, structural or generalized cumulative impulse responses. We discuss the...

  17. Output filters for AC adjustable speed drives

    Blaabjerg, Frede; Hanigovszki, Norbert; Landkildehus, Jorn, Jorn

    2007-01-01

    due to bearing currents, acoustic switching noise. Depending on the specific application, the mitigation of some of these effects (or all) might be necessary. The common solution for mitigating the secondary effects at the output of PWM-VSI is the use of output filters [3],[5],[6]. Several types...... of output filters are used and this paper presents an overview of the various output filter solutions typically employed in industrial applications. The paper does not propose any new solutions and it is intended as a guide for practicing engineers and a source of information for researchers....

  18. Rotor speed estimation for indirect stator flux oriented induction motor drive based on MRAS scheme

    Youssef Agrebi; Moncef Triki; Yassine Koubaa; Mohamed Boussak

    2007-01-01

    In this paper, a conventional indirect stator flux oriented controlled (ISFOC) induction motor drive is presented. In order to eliminate the speed sensor, an adaptation algorithm for tuning the rotor speed is proposed. Based on the model reference adaptive system (MRAS) scheme, the rotor speed is tuned to obtain an exact ISFOC induction motor drive. The reference and adjustable models, developed in stationary stator reference frame, are used in the MRAS scheme to estimate induction rotor peed...

  19. Speed of Adjustment to Selected Labour Market and Tax Reforms

    Annabelle Mourougane; Lukas Vogel

    2009-01-01

    This paper examines the length of economic adjustments to selected structural reforms, drawing on simulations with dynamic general equilibrium and macro-economic neo-Keynesian models. Employment adjustment costs appear to have only a limited effect on the pace of adjustment to reforms and the influence of price adjustment costs on output dynamics is found to be marginal. Accommodative monetary policy can speed up the adjustment to a new equilibrium, though to a varying degree in the different...

  20. Electric motor drive with infinitely variable speed transmission

    Tibbals, E.C. Jr.

    1983-07-05

    A drive system adapted for use in motor vehicles comprises an infinitely variable speed drive transmission coupled to a DC motor, and the speed ratio of the transmission is controlled by a speed-responsive flyweight or governor so as to maintain the DC motor at its most efficient operating level.

  1. Speed-calming measures and their Effect on driving speed

    Agerholm, Niels; Knudsen, Daniel; Variyeswaran, Kajan

    2016-01-01

    Speeding increases the risk and severity of accidents, especially for vulnerable road users. Hence, minimisation of speeding in built-up areas is vital. Some countries widely use speed-calming measures (SCs). Documentation shows that SCs reduce speeding considerably although various types and...... designs of SCs affect this reduction. This paper includes studies of the effects from establishment of sinus speed humps of height 10 cm and length 950 cm and chicanes (with a free carriageway width of 5,30 cm and a length between the 0.5 m wide obstacles of 18 m) as a before/after study where the speed....... Despite the apparent absence of more distant effects of each SC, there is an overall reduced average speed on the full length of a road with SCs. Humps reduce the mean speed comparable to the reduction from chicanes, but the speed variation is less reduced near chicanes, and especially prior to the...

  2. Speed choice and steering behavior in curve driving

    van Winsum, W.; Godthelp, J

    1996-01-01

    The relation between speed choice and steering performance during curve negotiation was studied in a driving simulator. The hypothesis was that curve radius and steering competence both affect steering error during curve driving, resulting in compensatory speed choice. In this, the control of safety

  3. To the Problem of Electromechanical Interaction in Elevators with Controlled Electric Drive and Fuzzy Speed Controller

    A. S. Koval

    2010-01-01

    Full Text Available The paper considers problems concerning electromechanical interaction in elevators with an adjustable asynchronous electric drive equipped with the vector control systems under direct torque control and direct torque control with pulse-width modulator. A mathematical description of electromechanical elevator system with due account of nonlinearity of the worm gear is given in the paper. The paper presents a simplified circuit design of a control system with a fuzzy speed controller. It has been established that the factor of electromechanical interaction in electromechanical system with the adjustable asynchronous electric drive and an fuzzy speed controller is within the range which corresponds to existence of the essential electromechanical interaction.

  4. Robust Underestimation of Speed During Driving: A Field Study.

    Schütz, Alexander C; Billino, Jutta; Bodrogi, Peter; Polin, Dmitrij; Khanh, Tran Q; Gegenfurtner, Karl R

    2015-12-01

    Traffic reports consistently identify speeding as a substantial source of accidents. Adequate driving speeds require reliable speed estimation; however, there is still a lack of understanding how speed perception is biased during driving. Therefore, we ran three experiments measuring speed estimation under controlled driving and lighting conditions. In the first experiment, participants had to produce target speeds as drivers or had to judge driven speed as passengers. Measurements were performed at daylight and at night. In the second experiment, participants were required to produce target speeds at dusk, under rapidly changing lighting conditions. In the third experiment, we let two cars approach and pass each other. Drivers were instructed to produce target speeds as well as to judge the speed of the oncoming vehicle. Here measurements were performed at daylight and at night, with full or dipped headlights. We found that passengers underestimated driven speed by about 20% and drivers went over the instructed speed by roughly the same amount. Interestingly, the underestimation of speed extended to oncoming cars. All of these effects were independent of lighting conditions. The consistent underestimation of speed could lead to potentially fatal situations where drivers go faster than intended and judge oncoming traffic to approach slower than it actually is. PMID:26562855

  5. Rotor speed estimation for indirect stator flux oriented induction motor drive based on MRAS scheme

    Youssef Agrebi

    2007-09-01

    Full Text Available In this paper, a conventional indirect stator flux oriented controlled (ISFOC induction motor drive is presented. In order to eliminate the speed sensor, an adaptation algorithm for tuning the rotor speed is proposed. Based on the model reference adaptive system (MRAS scheme, the rotor speed is tuned to obtain an exact ISFOC induction motor drive. The reference and adjustable models, developed in stationary stator reference frame, are used in the MRAS scheme to estimate induction rotor peed from measured terminal voltages and currents. The IP gains speed controller and PI gains current controller are calculated and tuned at each sampling time according to the new estimated rotor speed. The proposed algorithm has been tested by numerical simulation, showing the capability of driving active load; and stability is preserved. Experimental results obtained with a general-purpose 1-kW induction machine are presented showing the effectiveness of the proposed approach in terms of dynamic performance.

  6. Comparing a driving simulator to the real road regarding distracted driving speed

    Knapper, A.S.; CHRISTOPH,M; Hagenzieker, M.P.; Brookhuis, K.A.

    2015-01-01

    Relative and absolute validity of a driving simulator were assessed regarding effects on mean speed and speed variation during distracting secondary tasks, and normal driving. 16 participants drove the same route four times, twice in a simulator and twice in the real world. They performed way finding tasks, using either a paper map or a route guidance system, and mobile phone conversation tasks. Furthermore, driving without secondary tasks on other road segments in the two methods was compare...

  7. Comparing a driving simulator to the real road regarding distracted driving speed.

    Knapper, A. Christoph, M. Hagenzieker, M. & Brookhuis, K.

    2015-01-01

    Relative and absolute validity of a driving simulator were assessed regarding effects on mean speed and speed variation during distracting secondary tasks, and normal driving. 16 participants drove the same route four times, twice in a simulator and twice in the real world. They performed way finding tasks, using either a paper map or a route guidance system, and mobile phone conversation tasks. Furthermore, driving without secondary tasks on other road segments in the two methods was compare...

  8. Driving simulator validation for speed research on a horizontal curve

    CORNU, Joris; Ariën, Caroline; Gardeniers, Beau; BRIJS, Kris; Daniels, Stijn; Brijs, Tom; Wets, Geert

    2016-01-01

    his paper describes the results of a validation study of the fixed-base driving simulator of the Transportation Research Institute. The main objective of this study is to investigate the usefulness of the driving simulator as a tool for speed research on a horizontal curve on a two-lane rural road. Speed was collected at seven measurement points on this horizontal curve study area in the real world. This location was rebuilt in the driving simulator environment by use of the procedure called ...

  9. Musculoskeletal analysis of driving fatigue: The influence of seat adjustments

    Majid, Noor Aliah binti Abdul; Abdullah, Mohd Fareez Edzuan; Jamaludin, Mohd Syahmi;

    2013-01-01

    Main causes for discomfort experienced by vehicle drivers during driving were investigated using a rigid-body model originally developed in the AnyBody Modeling System [1]. The interactions between the human body and the car-seat in various combinations of seat-pan/backrest inclinations...... that various seat adjustments (e.g., seat-pan and backrest inclinations) and the pedal spring stiffness have complex influences on the muscle activation and spinal joint forces of the human body. From the results, an optimal adjustment for the car-seat is proposed, i.e. the backrest inclination is 10......° and the seat-pan inclination is between 0º to 5 º. This study can in general capture the overall interactions between human body and environment (i.e. the maximum muscle activity and spine forces), which is thought to be the factors of driving fatigue....

  10. A New Low-Cost Hybrid Switched Reluctance Motor for Adjustable-Speed Pump Applications

    Lu, Kaiyuan; Rasmussen, Peter Omand; Watkins, Steve;

    2011-01-01

    This paper presents a new low-cost hybrid switched reluctance (HSR) motor intended for use in adjustable-speed pump drive systems. The motor is a single-phase motor, driven by a unipolar converter, which uses both the reluctance torque and the permanent magnet interaction torque. Compared...... with conventional single-phase switched reluctance motors, it has an increased torque density. The cogging torque is beneficially used in this motor for reducing the torque ripple. It is demonstrated that such a motor drive system can be a suitable candidate to advantageously compete with the existing motor drive...... systems for low-cost applications. Finite-element models are used to analyze and predict the motor's performance. The proposed motor drive system has been fabricated, and its performance has been tested in the laboratory. These experimental results are also presented....

  11. PERFORMANCE OF SIX PHASE PMSM DRIVE AT DIFFERENT SPEED LEVELS

    Anurag Singh Tomer; S.P.Dubey

    2016-01-01

    This paper gives a detail modelling of six phase Permanent magnet synchronous machine (PMSM) and complete simulation of  it’s drive system and performance analysis in different speed with PI controller. proposed method can be used easily in many applications like ship propulsion, Hybrid electric vehicle, Washing machine, Ship propulsion, Traction, Spinning mills, Aerospace etc. Proportional-Integral controller is mostly used in drives system. The combination of proportional and int...

  12. Speed Control of PMSM Drives by Generalized Predictive Algorithms

    Belda, Květoslav; Vošmik, D.

    Montral : IEEE Industrial Electronics Society, 2012, s. 2002-2007. ISBN 978-1-4673-2419-9. [38th Annual Conference of the IEEE Industrial Electronics Society. Montreal (CA), 25.10.2012-28.10.2012] R&D Projects: GA ČR(CZ) GAP102/11/0437 Institutional support: RVO:67985556 Keywords : Generalized Predictive Control * PMSM Drives * Speed Control Subject RIV: BC - Control Systems Theory http://library.utia.cas.cz/separaty/2012/AS/belda-speed control of pmsm drives by generalized predictive algorithms.pdf

  13. Speed Control of Bldc Motor Drive By Using Pid Controllers

    Y.Narendra Kumar,

    2014-04-01

    Full Text Available This paper mainly deals with the Brushless DC (BLDC motor speed driving systems have sprouted in various small scale and large scale applications like automobile industries, domestic appliances etc. This leads to the development in Brushless DC motor (BLDCM. The usage of BLDC Motor enhances various performance factors ranging from higher efficiency, higher torque in low-speed range, high power density ,low maintenance and less noise than other motors. The BLDC Motor can act as an alternative for traditional motors like induction and switched reluctance motors. In this paper PID controller is implemented with speed feedback loop and it is observe that torque ripples are minimized. Simulation is carried out using MATLAB / SIMULINK. The results show that the performance of BLDC Motor is quite satisfactory for various loading conditions. Brushless DC motor drives are typically employed in speed controlled applications.

  14. Improved speed estimation in sensorless PM brushless AC drives

    Shen, J. X.; Zhu, Z.Q.; Howe, D.

    2002-01-01

    The application of flux-observer-based sensorless control to permanent-magnet brushless AC motor drives is described. Current methods of speed estimation are assessed, both theoretically and experimentally, and an improved method, which combines the best features of methods in which speed is derived from the differential of rotor position and from the ratio of the electromotive force to excitation flux linkage, is proposed. Its performance is verified experimentally.

  15. Sliding Mode Speed Control for DC Drive Systems

    Guldemir, H.

    2003-01-01

    In this study, the Sliding Mode Control theory of the Variable Structure System has been applied to the speed control of a de motor. The dynamic performance of the sliding mode speed control system has been studied against system parameter variations and external load disturbance and the simulation results are given. The application of the sliding mode control theory to controller design for DC drive control system shows a robust system performance.

  16. Urban Traffic Eco-Driving: Speed Advisory Tracking

    De Nunzio, Giovanni; Canudas de Wit, Carlos; Moulin, Philippe

    2014-01-01

    International audience The evaluation of the benefits of an Eco-Driving assistance system is carried out in the urban environment in presence of traffic lights. The traffic evolution is modeled macroscopically with the Urban Variable-Length Model in a variable speed limits framework. Under the assumption of equal boundary flows, the vehicles in a road section dispose themselves according to well defined equilibrium conditions which are dependent on the traveling speed in the free-flow part...

  17. Speed Control of Bldc Motor Drive By Using Pid Controllers

    Y.Narendra Kumar,; P.Eswara Rao

    2014-01-01

    This paper mainly deals with the Brushless DC (BLDC) motor speed driving systems have sprouted in various small scale and large scale applications like automobile industries, domestic appliances etc. This leads to the development in Brushless DC motor (BLDCM). The usage of BLDC Motor enhances various performance factors ranging from higher efficiency, higher torque in low-speed range, high power density ,low maintenance and less noise than other motors. The BLDC Motor can act ...

  18. Wind generator with electronic variable-speed drives

    David, A.; Buchheit, N.; Jakobsen, H.

    1996-12-31

    Variable speed drives have been inserted between the network and the generator on certain recent wind power facilities. They have the following advantages: the drive allows the wind generator to operate at low speed with a significant reduction in acoustic noise, an important point if the facilities are sited near populated areas; the drive optimizes energy transfer, providing a gain of 4 to 10 %; the drive can possibly replace certain mechanical parts (the starting system and it in some cases, the reduction gear); the drive not only provides better transient management in relation to the network for less mechanical stress on the wind generator, it is also able to control reactive power. One commercial drive design sold by several manufacturers has already been installed on several wind generators with outputs of between 150 and 600 kw. In addition, such a solution is extremely well suited to mixed renewable energy systems. This design uses two inverse rectifier type converters and can therefore exchange energy in both directions. The equivalent drive with a single IGBT converter on the motor side and a diode converter on the network side is the solution most widely adopted throughout industry (with more than 50, 000 units installed in France per year). It still remains to be seen whether such a solution could be profitable in wind generator application (since the cost of the drive is quite high). This technical analysis is more destined for the converter-machine assembly specialists and is presented in this document, paying particular attention as it does to the modelling of the `wind energy - generator - drive - network` assembly, the associated drive command and control strategies and the simulations obtained during various transients. A 7.5 kW test bed has been installed in the Laboratoire d`Electronique de Puissance de Clamart, enabling tests to be carried out which emulate the operation of a wind generator.

  19. To the Problem of Electromechanical Interaction in Elevators with Controlled Electric Drive and Fuzzy Speed Controller

    A. S. Koval; A. V. Shvayakou

    2014-01-01

    The paper considers problems concerning electromechanical interaction in elevators with an adjustable asynchronous electric drive equipped with the vector control systems under direct torque control and direct torque control with pulse-width modulator. A mathematical description of electromechanical elevator system with due account of nonlinearity of the worm gear is given in the paper. The paper presents a simplified circuit design of a control system with a fuzzy speed controller. It has be...

  20. MODELING AND ANALYSIS OF DISTRIBUTION LOAD CURRENTS PRODUCED BY AN AD JUSTABLE SPEED DRIVE HEAT PUMP

    Hoffman, Stephen Paul

    1993-01-01

    A number of demand side management techniques have been proposed for the efficient use of electric power in the commercial and residential sector. The adjustable speed drive heat pump is a technology which has the prospect of decreasing power demands for space heating. This design has the advantage over conventional designs of higher efficiency and, potentially, reduction of peak power demand. Its main disadvantage is higher cost. Further, it has the disadvantage that it produces a load curre...

  1. Nonlinear speed control of large industrial DC motor drives with an energy efficiency enhancement loop

    Sharaf, A. M.; Masry, M. [New Brunswick Univ., Dept of Electrical and Computer Engineering, Fredericton, NB (Canada)

    1998-11-01

    MATLAB simulation of a novel dynamic speed reference trajectory tracking controller using an error driven self-adjustable, self-regulating nonlinear control block is described. Results of the digital simulation of a DC motor drive system take into account the switching inherent delay and other drive/control nonlinearities. The addition of a slow-acting dynamic motor input power tracking loop ensures power energy efficiency, minimum inrush and associated supply line harmonics, minimum load excursions and reduced energy consumption in case of a cyclical inrush type motorized load. 11 refs., 5 figs.

  2. Automated robust control system design for variable speed drives

    Okaeme, Nnamdi

    2008-01-01

    Traditional PI controllers have been largely employed for the control of industrial variable speed drives due to the design ease and performance satisfaction they provide but, the problem is that these controllers do not always provide robust performance under variable loads. Existing solutions present themselves as complex control strategies that demand specialist expertise for their implementation. As a direct consequence, these factors have limited their adoption for the industrial control...

  3. Speed estimator for induction motor drive based on synchronous speed tracking

    S B Bodkhe; M V Aware; J G Chaudhari; J G Agrawal

    2015-06-01

    This paper presents a new open-loop speed estimation method for a three-phase induction motor drive. The open-loop speed estimators available in literature have the advantage of reduced computational stress over the observers but they share a common limitation of being largely dependent on flux and machine parameters. They involve integrations and differentiation in the algorithm that leads to serious error in estimation when subject to different operating conditions. The proposed estimator is based on synchronous speed tracking and is cost-effective. It is immune to any variation in machine parameters and noise. The synchronous speed is computed from stator frequency which is estimated on-line using the stator current signals. A unique, non-adaptive method for estimation of stator frequency within one-sixteenth of time period is also proposed to enhance the speed of estimation. Computer simulation and experimentation on a 2.2 kW Field oriented controlled induction motor drive is carried out to verify the performance of proposed speed estimator. The results show excellent response over a wide range of rotor speed in both directions including low speed and under different operating conditions. This confirms the effectiveness of the proposed method.

  4. Brushless DC motor Drive during Speed regulation with Current Controller

    Bhikshalu Manchala

    2015-04-01

    Full Text Available Brushless DC Motor (BLDC is one of the best electrical drives that have increasing popularity, due to their high efficiency, reliability, good dynamic response and very low maintenance. Due to the increasing demand for compact & reliable motors and the evolution of low cost power semiconductor switches and permanent magnet (PM materials, brushless DC motors become popular in every application from home appliances to aerospace industry. The conventional techniques for controlling the stator phase current in a brushless DC drive are practically effective in low speed and cannot reduce the commutation torque ripple in high speed range. This paper presents the PI controller for speed control of BLDC motor. The output of the PI controllers is summed and is given as the input to the current controller. The BLDC motor is fed from the inverter where the rotor position and current controller is the input. The complete model of the proposed drive system is developed and simulated using MATLAB/Simulink software. The operation principle of using component is analysed and the simulation results are presented in this to verify the theoretical analysis.

  5. Design of an Ultimate High Speed Electrical Drive System

    C. Vishnu Kiran

    2014-05-01

    Full Text Available New emerging applications in the areas of portable power generation, small turbocompressors and spindles require the development of ultrahigh-speed, low power electrical drives. A 500 000 r/min, 100 W electrical drive system is presented. Because of the ultrahigh-speed requirements, standard machine design and power electronic topology choices no longer apply and the complete drive system has to be considered. A permanent magnet machine with a slotless litz-wire winding is used, which results in a low motor inductance and a high fundamental machine frequency. Three different combinations of power electronic topologies and commutation strategies have been experimentally investigated. A voltage source inverter with block commutation and an additional dc–dc converter is selected as the most optimal choice for the power electronics interface as it results in the lowest volume of the entire drive system due to lower switching losses, no heat sink cooling required, a small number of semiconductor devices, and relatively simple control implementation in a low cost digitalsignal processor.

  6. VCA Direct-Drive High Speed and Precision XY Table

    ZHAO Xingyu; FENG Xiaomei; ZHANG Dawei

    2007-01-01

    In order to compensate for the limitation of conventional XY table used in semiconductor integrated circuits(IC) packaging and improve its speed and accuracy, a voice coil actuator (VCA)direct-drive high-speed and precision positioning XY table used in wire bonder was proposed. Also, a novel flexible decoupling mechanism was used in the positioning table, and the small moving mass enabled the positioning table to move at high speed and precision. XY table deformation interference caused by assembly error and instant interference generated by dynamic load moving with high speed and acceleration can be eliminated through the flexible decoupling mechanism. Considering the positioning table as lumped mass spring system, the dynamic equations of the mechanical sys-tem and the VCA were built according to the Newton mechanics principle and electromagnetic theory. Then the electromechanical coupling control model of the system was created through Laplace transform. Based on displacement PID controller, the Icop-locked controlling algorithm of the positioning system was investigated. The dynamic control algorithm effectively improved the system dynamic performance. The precision test of the prototype machine was carried out, and the results val-idated the correctness of the model and the theory. Compared with traditional XY table, the tablehas higher speed, acceleration and positioning accuracy.

  7. Harmonic Calculation Software for Industrial Applications with Adjustable Speed Drives

    Asiminoaei, Lucian; Hansen, S.; Blaabjerg, Frede

    2005-01-01

    This paper describes the evaluation of a new harmonic software. By using a combination of a pre-stored database and new interpolation techniques the software can very fast provide the harmonic data on real applications. The harmonic results obtained with this software have acceptable precision even...... with limited input data. The evaluation concludes here that this approach is very practical compared to other advanced harmonic analysis methods. The results are supported by comparisons of calculations and measurements given in an industrial application....

  8. Harmonic Calculation Toolbox in Industry Application for Adjustable Speed Drive

    Asiminoaei, Lucian; Blaabjerg, Frede; Hansen, Steffan

    2004-01-01

    Previous to electrical installation of large power non-linear loads, a comprehensive design-study is often required in order to determine if the overall installation complies with international regulations in respect to harmonics. Current THD voltage distortion and power factor are just few...

  9. MRAS state estimator for speed sensorless ISFOC induction motor drives with Luenberger load torque estimation.

    Zorgani, Youssef Agrebi; Koubaa, Yassine; Boussak, Mohamed

    2016-03-01

    This paper presents a novel method for estimating the load torque of a sensorless indirect stator flux oriented controlled (ISFOC) induction motor drive based on the model reference adaptive system (MRAS) scheme. As a matter of fact, this method is meant to inter-connect a speed estimator with the load torque observer. For this purpose, a MRAS has been applied to estimate the rotor speed with tuned load torque in order to obtain a high performance ISFOC induction motor drive. The reference and adjustable models, developed in the stationary stator reference frame, are used in the MRAS scheme in an attempt to estimate the speed of the measured terminal voltages and currents. The load torque is estimated by means of a Luenberger observer defined throughout the mechanical equation. Every observer state matrix depends on the mechanical characteristics of the machine taking into account the vicious friction coefficient and inertia moment. Accordingly, some simulation results are presented to validate the proposed method and to highlight the influence of the variation of the inertia moment and the friction coefficient on the speed and the estimated load torque. The experimental results, concerning to the sensorless speed with a load torque estimation, are elaborated in order to validate the effectiveness of the proposed method. The complete sensorless ISFOC with load torque estimation is successfully implemented in real time using a digital signal processor board DSpace DS1104 for a laboratory 3kW induction motor. PMID:26775088

  10. Analysis of Variable Speed PFC Chopper Fed BLDC Motor Drive

    A Jeya Selvan Renius

    2015-02-01

    Full Text Available This paper provides the detailed analysis of the DC-DC chopper fed Brushless DC motor drive used for low-power applications. The various methods used to improve the power quality at the ac mains with lesser number of components are discussed. The most effective method of power quality improvement is also simulated using MATLAB Simulink. Improved method of speed control by controlling the dc link voltage of Voltage Source Inverter is also discussed with reduced switching losses. The continuous and discontinuous modes of operation of the converters are also discussed based on the improvement in power quality. The performance of the most effective solution is simulated in MATLAB Simulink environment and the obtained results are presented.

  11. Empirical Evidence of Target Leverage, Adjustment Costs and Adjustment Speed of Non-Financial Firms in Selected African Countries

    Oyebola Fatima Etudaiye-Muhtar; Rubi Ahmad

    2015-01-01

    The issue of target leverage for corporate firms in developing countries has received little attention in extant literature, especially countries in Africa. Given the imperfection that exists in African financial markets that may limit firms access to external capital, this study investigates dynamic adjustment towards a target debt ratio. In addition, the study used a dynamic panel data estimation technique to determine adjustment costs and speed of adjustment in non-financial firms in selec...

  12. From Periphery to Core: Economic Adjustments to High Speed Rail

    Ahlfeldt, Gabriel M.; Feddersen, Arne

    2010-01-01

    This paper presents evidence that high speed rail systems, by bringing economic agents closer together, sustainably promote economic activity within regions that enjoy an increase in accessibility. Our results on the one hand confirm expectations that have led to huge public investments into high speed rail all over the world. On the other hand, they confirm theoretical predictions arising from a consolidate body of (New) Economic Geography literature taking a positive, man-made and reproduci...

  13. Efficiency characteristics of speed modulated drives at predicted torque conditions for air-to-air heat pumps

    Rice, C. K.

    Examples of system (motor + inverter drive) efficiencies of two types of adjustable speed control are compared for predicted compressor and indoor blower load profiles. The two classifications are inverter-driven induction motors (IDIMs) and permanent-magnet electronically commutated motors (PM-ECMs). Reference sine-wave-driven induction motor (SWDIM) efficiencies are also given. Available bench data on late 70's IDIM compressor drives are compared to recent data on IDIM and PM-ECM drives. The drive efficiencies are compared over common operating torque requirements for heating and cooling. A modulating heat pump model was used to develop predicted reciprocating compressor torque/drive-frequency mappings and the expected operating torque ranges. The variation in modulating compressor torque requirements is analyzed. Ways to adjust the torque relation for different compressor types and sizing strategies are also discussed. Modulating blower performance data on an early '80s generation modulating heat pump with an IDIM drive (and SWDIM reference drive) were obtained and compared to bench data on recent IDIM and PM-ECM drives under similar torque conditions. In both compressor and blower applications, the combined system efficiency of the PM-ECM drives is nearly equal to or higher than that of the reference SWDIM cases and significantly better than IDIMs available in the late '70s. When compared to more recent IDIMs, the PM-ECM efficiency advantage over IDIM compressors has been reduced 40 to 50 percent between half and nominal speed (3600 rpm) but still remains 14 to 9 percent higher, respectively.

  14. Experience in the Operation of Adjustable Electric Drives of Main Circulation Pumps of BN-600 Reactors

    Adjustable electric drives of the main circulation pumps of the BN-600 reactor of the Beloyarskaya NPP have a unique layout of asynchronous valve cascades (AVC). Twenty five years of successful operation of such drives prove the expediency of the use of AVC, which deserves study and application in the design of power units with BN-800 reactors

  15. Research on Control System of Spindle Drive for High Speed Spinning Machine

    魏建

    2001-01-01

    Through analyzing the principle of spindle drive of winding mechanism for high speed spinning machine,the article not only describes a kind of mode of spindle drive for take-up motion on the basis of control method of constant velocity winding, but also introduces the design technique of software and hardware for the control system of mechatronics of spindle drive mode for take- up motion on the basis of constant velocity winding for high speed spinning machine with single-chip microcomputer. The mathematical model to describe the spindle rotating speed is established. It is an important technology for high speed spinning machine and provides a feasible application way.

  16. Intelligent speed control and effects on driving behaviour

    Horst, A.R.A. van der; Hogema, J.H.

    1999-01-01

    Supporting the driver in conducting his nowadays demanding task is a promising means to get the maximum out of the road system with respect to both efficiency and safety. With respect to safety, speed management is a main issue. Police enforcement of speeding is one approach, preventing high speeds

  17. Rotor flux and speed estimators for induction motor drives

    Blaabjerg, Frede; Teodorescu, Remus; Zelechowski, M.; Lach, P.; Rozanski, P.

    Flux and rotor speed observer is required for sensorless control of induction motor. This paper shows some different methods of estimation. There are two flux and three rotor speed estimators, which were chosen from the most promising methods presented in literature. Description of control system...

  18. Variable-speed drive and control systems for rolling mills; Atsuenkiyo drive seigyo system

    Kasai, T.; Tochigi, T. [Fuji Electric Co. Ltd., Tokyo (Japan)

    2000-11-10

    The drive systems of large rolling mills is of a cycloconverter type, a GTO (gate turn-off thyristor) type or high-voltage IGBT (insulated gate bipolar transistor) type. Drive systems for bar, rod and pipe mills use three and/or two level IGBT inverters. This paper describes recent technical trends of drives and control systems in rolling mills, including each drive application and the PLC (programmable controller) and HCI (human communication interface) controlling the total rolling mill line. (author)

  19. Internal Model Controller of an ANN Speed Sensorless Controlled Induction Motor Drives

    Hamed Mouna, Ben; Lassaad, Sbita

    This study deals with the performance analysis and implementation of a robust sensorless speed controller. The robustness is guaranteed by the use of the Internal Model Controller (IMC). An intelligent algorithm is evolved to eliminate the mechanical speed. It is based on the Artificial Neural Network (ANN) principle. Verification of the proposed robust sensorless controller is provided by experimental realistic tests on a scalar controlled induction motor drive. Sensorless robust speed control at low speeds and in field weakening region (high speeds) is studied in order to show the robustness of the speed controller under a wide range of load.

  20. Using variable speed drives technology to reap rewards of efficient HVAC design

    Electric motors are continuously running at full speed with vanes and throttles used to modulate the output, in most HVAC applications. This results in an excessive wastage of electrical energy, and the solution is the variable speed drive, which can save vast amounts of energy in fans, pumps and compressors across the HVAC system. Users of traditional control methods will not benefit from the energy savings that are possible through variable speed drives because the motor speed remains the same, with the result that some, and in some cases most, of the energy drawn will be wasted. Variable speed drives are more efficient because they control output by regulating the motor speed, rather than run the motor at full speed and use restrictions to reduce the flow. Recently, small so-called micro-drives have been launched, cutting the cost for most variable speed operation. Variable speed motors can also introduce new features to the HVAC system. An example of how drives can save money and improve the indoor climate is cited for Heathrow airport. There, the gateroom was earlier controlled by modulating valves in both heater and cooler coils, with two fans that operated continuously at rated speed. This system was very inefficient because the occupancy of the gateroom varied between zero and maximum several times daily. A new system was installed using two AC drives, in which one drive controls the supply air fan and the other the return air fan. The energy savings amounted to 89% during two tests and 77% in a third. A pump installation in the district heating system of Strasbourg, Germany, showed the savings that are possible in pump applications

  1. Self-mixing interferometry for rotational speed measurement of servo drives.

    Sun, Hui; Liu, Ji-Gou; Zhang, Quan; Kennel, Ralph

    2016-01-10

    Self-mixing interferometry (SMI) is an efficient technique applied to measure distance, velocity, displacement, and vibration. In this work, a compact and low cost SMI is applied to measure the rotational speed of a servo drive up to 6000 RPM. The application of SMI to rotational speed measurement of servo drives instead of the usage of incremental encoders is proposed. The Doppler frequency is obtained via analysis on the power spectral density, which is estimated by the smoothing periodogram method based on the fast Fourier transformation. The signals are processed in MATLAB and LABVIEW, showing that the SMI can be applied to dynamic rotational speed measurement of servo drives. Results of experiments demonstrate that this system is implementable for rotational speed measurement over the whole range from 3 RPM to 6000 RPM. In addition, the system used to measure rotational speed can also accurately record changes in position without integrating the velocity. PMID:26835757

  2. Induction generator produces constant-frequency voltage from variable-speed drive

    Riaz, M.

    1970-01-01

    Two-stage polyphase generator is usable as induction motor operable over range of speeds while powered from constant frequency source. It requires neither slip rings nor special adjustable-frequency power supplies or external reactive sources.

  3. Speed-Sensorless DTC-SVM for Matrix Converter Drives With Simple Nonlinearity Compensation

    Lee, Kyo Beum; Blaabjerg, Frede; Yoon, Tae-Woong

    2007-01-01

    This paper presents a new method to improve the sensorless performance of matrix converter drives using a parameter estimation scheme. To improve low-speed sensorless performance, the nonlinearities of a matrix converter drive such as commutation delays, turn-on and turn-off times of switching de...

  4. Speed-Sensorless DTC-SVM for Matrix Converter Drives With Simple Non-Linearity Compensation

    Lee, Kyo-Beum; Blaabjerg, Frede; Yoon, Tae-Woong

    2005-01-01

    This paper presents a new method to improve sensorless performance of matrix converter drives using a parameter estimation scheme. To improve low-speed sensorless performance, the non-Iinearities of a matrix converter drive such as commutation delays, turn-on and turn-off times of switching devic...

  5. Speed Loop Control of PMSM Driving Electric Vehicle

    Guo, Yougui; Zeng, Ping; Zhu, Jieqiong;

    2011-01-01

    Various simulation models are set up and closed speed loop control strategy of PMSM is proposed based on flux weakening control in this paper. First the model of maximum torque per ampere(MTPA) is modeled based on mathematical models and gave the corresponding simulation tests. Second the formula...

  6. Sensorless Speed Control including zero speed of Non Salient PM Synchronous Drives

    Rasmussen, Henrik

    2005-01-01

    including the rotor speed. Assuming motor parameters known the design achieves stability with guaranteed region of attraction even at zero speed. The control method is made robust at zero and low speed by changing the direct vector current component to a value different from zero. In order to verify the...

  7. Novel wide range speed control of permanent magnet brushless motor drives

    Chau, KT; Chan, CC; Jiang, JZ; Xia, W

    1995-01-01

    This paper presents a novel approach for wide range speed control of permanent magnet (PM) brushless motor drive, including both sinewave and squarewave versions. As compared with conventional flux-weakening control, the approach takes definite advantages that it can be applied to the squarewave PM brushless motor drive directly, and even to the motor drive with negligible mutual inductances between phase windings. Moreover, it is easier to implement than flux-weakening control because no coo...

  8. An extended induction motor model for investigation of faulted machines and fault tolerant variable speed drives

    Jasim, Omar

    2010-01-01

    High performance variable speed induction motor drives have been commercially available for industrial applications for many years. More recently they have been proposed for applications such as hybrid automotive drives, and some pump applications on more electric aircraft. These applications will require the drive to operate in the presence of faults i.e. they must be “Fault Tolerant” and be capable of “Fault Ride Through”. The aim of this project was therefore to investigate fault ride thro...

  9. Simulation Of 3-Ph To 3-Ph Cycloconverter Fed Variable Speed Drive

    Keshav B Negalur#1 , A.S.Joshikulkarni

    2013-01-01

    With harmonic distortion becoming an ever increasing concern in Variable Speed Drive (VSD) applications, virtually all Drive, manufacturers now consider limiting the generation of input current harmonics to be an important issue in their designs. This has led us to the introduction of various drives which should give us considerable reduction in the harmonic distortion. In practical application, the three-phase to threephase cycloconverter is commonly required to derive a threephase output fr...

  10. A Digital Phase Locked Loop Speed Control of Three Phase Induction Motor Drive: Performances Analysis

    Ben Hamed Mouna; Sbita Lassaâd

    2011-01-01

    This paper deals with performance analysis and implementation of a three phase inverter fed induction motor (IM) drive system. The closed loop control scheme of the drive utilizes the Digital Phase Locked Loop (DPLL). The DPLL is safely implemented all around the well known integrated circuit DPLL 4046. An ex-perimental verification is carried out on one kw scalar controlled IM system drives for a wide range of speeds and loads appliance. This presents a simple and high performance solution f...

  11. Brushless DC motor Drive during Speed regulation with Current Controller

    Bhikshalu Manchala; T.Amar Kiran

    2015-01-01

    Brushless DC Motor (BLDC) is one of the best electrical drives that have increasing popularity, due to their high efficiency, reliability, good dynamic response and very low maintenance. Due to the increasing demand for compact & reliable motors and the evolution of low cost power semiconductor switches and permanent magnet (PM) materials, brushless DC motors become popular in every application from home appliances to aerospace industry. The conventional techniques for controlling...

  12. A speed estimation of sensorless control for asymmetrical parameter type two-phase induction motor drives

    Nuttapong Muangchan

    2015-06-01

    Full Text Available This paper presents the concept of a speed estimation of sensorless control for asymmetrical parameter type two-phase induction motor drive, by using the adaptive observer system. The motor speed is estimated on the rotor-flux reference frame to simplicity for application. The design guideline of the gain of speed estimate system for a motor has speed change. The experimental results for all test conditions show that the responses of current, torque and speed are stable for the entire operating region.

  13. Maximum Efficiency Point Tracking for Adjustable-Speed Small Hydro Power Plant

    BORGHETTI Alberto; Di Silvestro, Mauro; Naldi, Gleb; Paolone, Mario; Alberti, Massimo

    2008-01-01

    The paper presents the general scheme and the relevant implementation of a Maximum Efficiency Point Tracking (MEPT) system for a Small Hydro Power (SHP) plant equipped with a variable-speed generator. This last consists of a Doubly Fed Induction Generator (DFIG) and a power electronic converter that independently controls both the rotor speed and the generator power factor. The MEPT is designed to be used with a propeller turbine with adjustable runner blade angle and it is coupled with the h...

  14. Measuring the impact of digital information displays on speed: a driving simulator study

    CORNU, Joris

    2012-01-01

    The primary objective of this study is to examine the impact of digital information displays on driving behavior at 70 km/h to 50 km/h transition zones. Therefore, two real world locations with a high percentage of speeding violations are rebuilt as realistic as possible in a driving simulator. Sixty-six participants completed an 18.9km trip within a randomized between (location: A, B) -within (condition: no display, smiley, 'You are speeding!', 'Speed control') subject design. Results show t...

  15. The impact of personality on driving safety among Chinese high-speed railway drivers.

    Guo, Ming; Wei, Wei; Liao, Ganli; Chu, Fulei

    2016-07-01

    This study explored the impact of personality traits on driving safety in high-speed railway drivers. A sample of high-speed railway drivers in Beijing (N=214) completed a questionnaire, including information on personality traits and background variables. The NEO Five Factor Inventory (NEO-FFI) was administered to characterize participants based on five personality traits: Neuroticism, Extraversion, Agreeableness, Openness to Experience, and Conscientiousness. The survey data were combined with naturalistic data of accident involvement and risky driving behavior in China. Poisson regression results show that drivers with high Conscientiousness and Extraversion caused fewer accidents. Higher Conscientiousness and lower Agreeableness were related to less frequent risky driving behavior. Education level and age negatively moderated the relation between certain personality traits and driving safety. The findings suggest that personality traits should be considered when selecting and training high-speed railway drivers. PMID:27035394

  16. Very-low-speed variable-structure control of sensorless induction machine drives without signal injection

    Lascu, Christian; Boldea, Ion; Blaabjerg, Frede

    2005-01-01

    A sensorless induction machine drive is presented, in which the principles of variable-structure control and direct torque control (DTC) are combined to ensure high-performance operation in the steady state and under transient conditions. The drive employs a new torque and flux controller, the...... "linear and variable-structure control", which realizes accurate and robust control in a wide speed range. Conventional DTC transient merits are preserved, while the steady-state behavior is significantly improved. The full-order state observer is a sliding-mode one, which does not require the rotor speed...... adaptation and provides accurate state estimation in the entire speed range. The proposed scheme is a complete variable-structure solution that allows persistent sensorless operation of the drive at very low speeds, including zero and 3 r/min, with full load. Simulations and extensive experimental results...

  17. Energy Efficient Control of High Speed IPMSM Drives - A Generalized PSO Approach

    GECIC, M.

    2016-02-01

    Full Text Available In this paper, a generalized particle swarm optimization (GPSO algorithm was applied to the problems of optimal control of high speed low cost interior permanent magnet motor (IPMSM drives. In order to minimize the total controllable electrical losses and to increase the efficiency, the optimum current vector references are calculated offline based on GPSO for the wide speed range and for different load conditions. The voltage and current limits of the drive system and the variation of stator inductances are all included in the optimization method. The stored optimal current vector references are used during the real time control and the proposed algorithm is compared with the conventional high speed control algorithm, which is mostly voltage limit based. The computer simulations and experimental results on 1 kW low cost high speed IPMSM drive are discussed in details.

  18. Offset Compound Gear Inline Two-Speed Drive

    Stevens, Mark A. (Inventor); Handschuh, Robert F. (Inventor); Lewicki, David G. (Inventor)

    2014-01-01

    A two-speed transmission having an input shaft and an output shaft, the transmission being capable of transitioning between fixed ratios, the high-range ratio being direct 1:1 and the low-range ratio being about 2:1. The transmission is a simple lightweight, yet robust, configuration utilizing only two gear meshes, being comprised of an input gear, a cluster gear, and an output gear. The transmission is controlled with a clutch and a sprag and with the input and output shafts turning in the same direction.

  19. Operating Regions of Adjustable-Speed Units with Doubly Fed Machines

    Schreier, Luděk; Chomát, Miroslav; Bendl, Jiří

    2004-01-01

    Roč. 49, č. 2 (2004), s. 119-136. ISSN 0001-7043 R&D Projects: GA AV ČR IAA2057102 Keywords : AC machines * adjustable-speed systems * doubly fed machine Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  20. Pipeline clean-up : speed, environment drive pipelining equipment

    Budd, G.

    2004-08-01

    Horizontal drilling technology is the single most important enhanced oil recovery technology which has resulted in a significant increase in pipeline utilization. Pipeline operators such as Calgary-based Denim Pipeline Construction Ltd. are responding by using the latest equipment, including excavation equipment, to avoid maintenance delays and downtime. The sales of Denim's horizontal pipe bending equipment have increased due to their attention to worker safety. Denim's horizontal bending machine does not require as much technical support, plus it is faster to install and speeds up production. The machine consists of 3 hydraulic jacks that move on a horizontal plate. Curved dies can be modified to accommodate various diameters of pipe. The bending operation is performed very near to the ground, thereby significantly reducing the risk of pipe injury. Environmental damage is minimized through the use of mechanized mulching which has replaced burning of unwanted trees and brush to clean for pipelines. 1 fig.

  1. Adjustable speed operation of a hydropower plant associated to an irrigation reservoir

    This paper deals with the issue of adjustable speed operation (ASO) of hydropower plants. The main idea of this technique is to allow the turbine speed to change in accordance with hydraulic conditions, thus improving the overall unit efficiency. General technical aspects of ASO are further discussed with special emphasis on the energy and operational benefits that may potentially result from its application. In order to assess these benefits, annual operation of a hydropower plant associated to an irrigation reservoir has been simulated under different scenarios, with both adjustable and fixed speed. Turbine operating range proved to be wider with ASO. In addition, simulation results confirm that considerable energy gains are expected to be obtained

  2. Prediction of Driving Ability with Neuropsychological Tests: Demographic Adjustments Diminish Accuracy

    Barrash, Joseph; Stillman, Ashley; Anderson, Steven W; UC, Ergun Y; Dawson, Jeffrey D.; Rizzo, Matthew

    2010-01-01

    Demographically-adjusted norms are used to enhance accuracy of inferences based on neuropsychological assessment. However, we hypothesized that predictive accuracy regarding complex real-world activities is diminished by demographic corrections. Driving performance was assessed with a standardized on-road test in participants aged 65+ (24 healthy elderly, 26 Alzheimer’s disease, 33 Parkinson’s disease). Neuropsychological measures included Trailmaking A and B, Complex Figure, Benton Visual Re...

  3. Two wheel speed robust sliding mode control for electric vehicle drive

    Abdelfatah Nasri

    2008-01-01

    Full Text Available Nowadays the uses of electrical power resources are integrated in the modern vehicle motion traction chain so new technologies allow the development of electric vehicles (EV by means of static converters-related electric motors. All mechanical transmission devices are eliminated and vehicle wheel motion can be controlled by means of power electronics. The proposed propulsing system consists of two induction motors (IM that ensure the drive of the two back driving wheels. The proposed control structure-called independent machines- for speed control permit the achievement of an electronic differential. The electronic differential system ensures the robust control of the vehicle behavior on the road. It also allows controlling independently, every driving wheel to turn at different speeds in any curve. This paper presents the study and the sliding mode control strategy of the electric vehicle driving wheels.

  4. Intraday Speed of Adjustment and the Realized Variance in the Indonesia Stock Exchange

    Zaafri A Husodo

    2009-01-01

    Full Text Available We examine the intraday trading and price dynamics for frequently traded stocks at the Indonesian Stock Exchange. Using trade price, time series generated at one, two, three, five, ten, fifteen, thirty and sixty-minute intervals, we estimate the speed of adjustment and the corresponding realized variance of these series. The objective of the estimation is to infer the noise impact to the deviation of observed prices from their fundamental value. The result from the speed of adjustment estimate is consistent with the realized variance estimator. Both conclude that the 50 most frequently traded stocks in the Indonesia Stock Exchange adjust to new information within 30 minutes. At the interval, the coefficient of the speed of price adjustment is insignificantly different from zero implying negligible noise impact to the observed price. Concurrently, the realized variance starts to stabilize at 30-minute interval purporting fading impact of noise to the realized variance estimate. The evidence justifies the use of realized variance at various intervals as a reliable indicator of price discovery rate in the Indonesia Stock Exchange.

  5. Simplified Fuzzy Control for Flux-Weakening Speed Control of IPMSM Drive

    M. J. Hossain

    2011-01-01

    Full Text Available This paper presents a simplified fuzzy logic-based speed control scheme of an interior permanent magnet synchronous motor (IPMSM above the base speed using a flux-weakening method. In this work, nonlinear expressions of d-axis and q-axis currents of the IPMSM have been derived and subsequently incorporated in the control algorithm for the practical purpose in order to implement fuzzy-based flux-weakening strategy to operate the motor above the base speed. The fundamentals of fuzzy logic algorithms as related to motor control applications are also illustrated. A simplified fuzzy speed controller (FLC for the IPMSM drive has been designed and incorporated in the drive system to maintain high performance standards. The efficacy of the proposed simplified FLC-based IPMSM drive is verified by simulation at various dynamic operating conditions. The simplified FLC is found to be robust and efficient. Laboratory test results of proportional integral (PI controller-based IPMSM drive have been compared with the simulated results of fuzzy controller-based flux-weakening IPMSM drive system.

  6. Modeling and Analysis of PI Controller Based Speed Control of Brushless DC Motor Drive.

    Mr.P.Nagasekhar Reddy

    2013-09-01

    Full Text Available The Brushless DC motors (BLDC find widespread applications in domestic and industries due to their low and high power density and ease of speed control. To accomplish desired level of performance the motor requires suitable speed controllers. In case of permanent magnet Brushless DC motors, usually control of speed is reached by using proportional integral (PI controller. Although the conventional PI controllers are widely used in the industry due to their simple control structure and ease of implementation, these controllers pose difficulties where there are some control complexity such as nonlinearity, load disturbances and parametric variations. Moreover PI controllers require precise linear mathematical models. In this paper, the analysis and mathematical modeling of BLDC motor is implemented. Also, speed control of three phase BLDC motor drive using power electronic device is projected by using matlab/Simulink. The simulation result shows the improved performance of developed Brushless DC motor drive.

  7. Determination of the energy performance of the pumping unit with adjustable electric drive

    Соколовський, Олег Феліксович

    2015-01-01

    Consumption power by pumping unit with adjustable electric is determined by the chosen algorithm and network control. This requires careful analysis of phenomenon of cell loss in power channel. To determine the energy losses in asynchronous motors must know the variation of motor current during transient or analytical expression change of speed over time and reliable data stator winding in case of change of temperature. Energy losses in the pump may determined by the data input and output. No...

  8. Design and static performance of high speed machining centre with "direct drive"

    Shuhong XIAO; Yulian CHEN; Guangyuan ZHENG

    2009-01-01

    "Direct drive" is an ideal method for speeding machine tools. In the structure of a CNC machining centre with "direct drive", the linear motor's primary and secondary parts are assembled into the worktable and machine bed respectively to directly drive the worktable. The built-in rotary motor is assembled in the spindle to realize the main transmission system of the machine tool "direct drive". All mechanical transmission elements in machine tools are eliminated. High speed, efficiency, and accuracy are easily obtained. However, in this type of "direct drive" machining centre, the magnetic attraction force between the primary and the secondary linear motors and the dynamic impact at acceleration and deceleration are directly imposed on the machine tool, and influence the performance of the machining centre. This paper analyzes the special demands of "direct drive" on the machine centre, and introduces a new structure of the machining tool. The worktable and machine bed are optimized to meet the special demands of "direct drive". Static performance simulation on the machining centre is done to reveal an ideal result.

  9. Speed-accuracy trade-off behavior: Response caution adjustment or mixing task strategies?

    van Maanen

    2015-01-01

    The speed-accuracy trade-off (SAT) effect refers to the behavioral trade-off between fast yet error-prone responses and accurate but slow responses. Multiple theories on the cognitive mechanisms behind SAT exist. One theory assumes that SAT is a consequence of strategically adjusting the amount of evidence required for overt behaviors, such as perceptual choices. Another theory hypothesizes that SAT is the consequence of mixing different task strategies. In this paper these theories are disam...

  10. Senserless Speed and Position of Direct Field Orientation Control Induction Motor Drive

    Mohammed Khalil Hussain

    2012-01-01

    Full Text Available Direct field-orientation Control (DFOC of induction motor drives without mechanical speed sensors at the motor shaft has the attractions of low cost and high reliability. To replace the sensor, information on the rotor speed and position are extracted from measured stator currents and from voltages at motor terminals. In this paper presents direct field-orientation control (DFOC with two type of kalman filter (complete order and reduced order extended kalman filter to estimate flux, speed, torque and position. Simulated results show how good performance for reduced order extended kalman filter over that of complete order extended kalman filter in tracking performance and reduced time of state estimation.

  11. Novel Position and Speed Estimator for PM Single Phase Brushless D.C. Motor Drives

    Lepure, Liviu I.; Andreescu, Gheorghe-Daniel; Iles, Doris;

    2010-01-01

    A novel position and speed estimator for single phase permanent magnet brushless d.c. (PMBLDC) motor drives, based on flux integration and prior knowledge of ΨPM (θ) is proposed here and an adequate correction algorithm is adopted in order to increase the robustness to noise and to reduce the...... sensitivity to accuracy of flux linkage estimation. A speed and current close loop control is employed based on the Hall signal and the motor is controlled at different speeds in order to validate the proposed estimation algorithm with satisfying results. The position correction effect is analyzed by...

  12. Speed regulated drives save energy and operating cost; Drehzahlvariable Antriebe senken Energie- und Betriebskosten

    Possberg, Norbert

    2009-12-15

    The cement factory of the Lafarge group at Hope, United Kingdom, retrofitted the last two drive units of the production chain by an electronic speed regulation. By utilization of frequency converters in the cooler ventilation sector the total energy consumption lowered to more than 15 %. (orig./GL)

  13. Comparative Study of Fuzzy Logic Based Speed Control of Multilevel Inverter fed Brushless DC Motor Drive

    Pritha Agrawal

    2014-02-01

    Full Text Available This paper presents a comparative analysis of speed control of brushless DC motor (BLDC drive fed with conventional two-level, three and five level diode clamped multilevel inverter (DC-MLI. The performance of the drive system is successfully evaluated using Fuzzy Logic (FL based speed controller. The control structure of the proposed drive system is described. The speed and torque characteristic of conventional two-level inverter is compared with the three and five-level multilevel inverter (MLI for various operating conditions. The three and five level diode clamped multilevel inverters are simulated using IGBT’s and the mathematical model of BLDC motor has been developed in MATLAB/SIMULINK environment. The simulation results show that the Fuzzy based speed controller eliminate torque ripples and provides fast speed response. The developed Fuzzy Logic model has the ability to learn instantaneously and adapt its own controller parameters based on disturbances with minimum steady state error, overshoot and rise time of the output voltage.

  14. The Digital PI Control for Driving Constant Speed of Brushless DC Motor

    Yoon, Shin Yong; Kim, Yong; Baek, Soo Hyun [Dongguk University (Korea); Kim, Hyun Soo [Chang Hung Telecom Co., Ltd. (Korea); Kim, Il Nam [Dongseoul College (Korea)

    2000-06-01

    This paper presents the improvement for speed characteristics of a Brushless DC Motor (BLDCM), it was applied to digital PI control for this. The practical PID control has been widely used to velocity control of DC motor. In this paper, a digital PI controller is used in order to decrease to speed error in constant velocity control of BLDCM. A TMS320C31 DSP is used for the microprocessor of digital PI control. The method using the DSP carry out the real-time control. The DSP has the rapid calculation ability and sampling time used 1ms. Driving BLDCM used 50W, motor input DC 150V and rotation speed 3000rpm. When BLDCM is to approval for discretion velocity at the acceleration and deceleration driving with any load, it was a feasible for stabilization control. Therefore, the experimental results indicate the superiority and validity of the velocity control by digital PI control. (author). 7 refs., 15 figs., 2 tabs.

  15. Closed Loop Speed Control of a BLDC Motor Drive Using Adaptive Fuzzy Tuned PI Controller

    Sri Latha Eti

    2014-11-01

    Full Text Available Brushless DC Motors are widely used for many industrial applications because of their high efficiency, high torque and low volume. This paper proposed an improved Adaptive Fuzzy PI controller to control the speed of BLDC motor. This paper provides an overview of different tuning methods of PID Controller applied to control the speed of the transfer function model of the BLDC motor drive and then to the mathematical model of the BLDC motor drive. It is difficult to tune the parameters and get satisfied control characteristics by using normal conventional PI controller. The experimental results verify that Adaptive Fuzzy PI controller has better control performance than the conventional PI controller. The modeling, control and simulation of the BLDC motor have been done using the MATLAB/SIMULINK software. Also, the dynamic characteristics of the BLDC motor (i.e. speed and torque as well as currents and voltages of the inverter components are observed by using the developed model.

  16. How Much Degrees Of Temperature A Warp Drive Achieves When At Superluminal Speeds?? The Analysis Of Gonzalez-Diaz Applied To The Natario Warp Drive Spacetime

    Loup, Fernando

    2013-01-01

    Warp Drives are solutions of the Einstein Field Equations that allows superluminal travel within the framework of General Relativity.There are at the present moment two known solutions: The Alcubierre warp drive discovered in $1994$ and the Natario warp drive discovered in $2001$.The warp drive seems to be very attractive because allows interstellar space travel at arbitrarily large speeds avoiding the time dilatation and mass increase paradoxes of Special Relativity. However it suffers from ...

  17. ANALYSIS OF VARIABLE SPEED PFC BUCK–BOOST CONVERTER-FED PMBLDC MOTOR DRIVE

    K. Raghavareddy

    2015-09-01

    Full Text Available This paper presents an analysis of variable speed low power drive with PFC at supply ends by using BLDC PM motor fed from buck-boost converter. The speed control of BLDC achieved by simply control the DC link voltage of VSI converter which is taken as reference signal. This facilitates the operation of VSI at fundamental frequency switching by using the electronic commutation of the BLDC motor which offers reduced switching losses. A PFC buck–boost converter is designed to operate in discontinuous inductor current mode (DICM to provide an inherent PFC at ac mains. The performance of the proposed drive is evaluated over a wide range of speed control and varying supply voltages (universal ac mains at 170–270 V with improved power quality at ac mains. The obtained power quality indices are within the acceptable limits of international power quality standards such as the IEC 61000-3-2. The performance of the proposed drive is simulated in MATLAB/Simulink environment, and the obtained results are validated experimentally on a developed prototype of the drive.

  18. Wavelet transform with fuzzy tuning based indirect field oriented speed control of three-phase induction motor drive

    Sanjeevikumar, P.; Daya, J.L. Febin; Wheeler, Patrick;

    2015-01-01

    This manuscript presents the details about the novel controller using wavelet transform and fuzzy logic tuning for speed control of an induction motor drive. The conventional proportional-integral (PI) speed controller in an indirect vector control of induction motor drive has been replaced by th...

  19. Field Oriented Control for Rotor Position Estimation of IPM Drives over a Wide Speed Range

    Ekhlas Kadhum

    2013-01-01

    Full Text Available Field oriented control strategy of Interior Permanent Magnet IPM Synchronous Motor drives over a wide speed range applications is presented. Rotor position estimation using model reference adaptive system method for IPM Drive without using a mechanical sensor is illustrated considering the effects of cross-saturation between the d and q axes. The cross saturation between d and q axes has been calculated by finite-element analysis. The inductance measurement regards the cross saturation which is used to obtain the suitable id - characteristics in base and flux weakening regions. The simulation results show that rotor position estimation error accuracy was improved. Various dynamic conditions have been investigated

  20. Investigation of Road Enviroment Effects on Choice of Urban and Interurban Driving Speed

    Ádám Török

    2011-03-01

    Full Text Available Human factor plays the most determinant role in traffic accidents. Speeding is a dominant cause of accidents in road transport. However, in order to improve safety, this is not the only element of the road transport system that should be considered. The road and/ or environment influence that behaviour as well, but they can be modified more quickly than drivers’ behaviour, and their effect can also be demonstrated. This paper describes the effect of road environment on chosen driving speed. Decisions of drivers are influenced by environmental impacts. Some of these impacts are planned, deliberate stimuli, being a part of the telematic systems of traffic control. In this paper the measure of road vehicles speed was analyzed on certain road urban and interurban sections which can be characterized by different design speed and construction parameters. Methods of mathematical statistics have been used to prove the hypothesis; the driving speed chosen by the driver depends heavily on the characteristics of urban and interurban road section. The aim of the author is to prove this hypothesis and the difference between urban and interurban decision environment.

  1. A Study of Hydrogen Generation with Doubly-Fed Adjustable Speed Wind Generator

    Kinoshita, Hirotaka; Takahashi, Rion; Murata, Toshiaki; Tamura, Junji; Sugimasa, Masatoshi; Komura, Akiyoshi; Futami, Motoo; Ichinose, Masaya; Ide, Kazumasa

    This paper presents a combination system of wind power generator and hydrogen generator. In the proposed system, Doubly-Fed Synchronous Generator (DFSG) is used as an adjustable speed wind generator, and an electrolyzer is connected to its terminal for hydrogen generation, which is controlled by power electronic converters. Output power from the wind generator is smoothed and supplied to the power system as well as to the electrolyzer to generate hydrogen under a cooperative control of the wind generator and the electrolyzer. The performance of the proposed system is investigated by simulation analyses, in which simulations are performed by using PSCAD/EMTDC.

  2. A high speed camera with auto adjustable ROI for product's outline dimension measurement

    Wang, Qian; Wei, Ping; Ke, Jun; Gao, Jingjing

    2014-11-01

    Currently most domestic factories still manually detect machine arbors to decide if they meet industry standards. This method is costly, low efficient, and easy to misjudge the qualified arbors or miss the unqualified ones, thus seriously affects factories' efficiency and credibility. In this paper, we design a specific high-speed camera system with auto adjustable ROI for machine arbor's outline dimension measurement. The entire system includes an illumination part, a camera part, a mechanic structure part and a signal processing part based on FPGA. The system will help factories to realize automatic arbor measurement, and improve their efficiency and reduce their cost.

  3. Performance Indices Based Optimal Tunning Criterion for Speed Control of DC Drives Using GA

    Deepti Singh

    2014-12-01

    Full Text Available This paper presents a framework to carry out a simulation to tune the speed controller gains for known input of DC drive system. The objective is to find the optimal controller gains (proportional and integral in a closed loop system. Various performance indices have been considered as optimal criterion in this work. The optimal gain values have been obtained by conventional and Genetic Algorithm (GA based optimization methods. The study has been conducted on a simulink model of three phase converter controlled direct current (DC drive with current and speed control strategy. The results show that the GA based tunning provided better solutions as compared to conventional optimization methods based tunning.

  4. An Approach to Synthesis of a Class of Electric Drives with Dual-Zone Speed Control

    GEORGIEV, T.

    2010-11-01

    Full Text Available An approach to dual-zone speed control of DC motor electric drives is presented in this paper. The new point is that in the syntheses of controllers a combination between setting of closed-loop system poles (modal control and optimal control through the quadratic quality criterion minimization is applied. Optimal modal control is achieved whereat a new type of complex criterion for selection of the functional is used. This approach allows taking into consideration the controlled object parameters' change at determination of the optimal modal controller coefficients when speed is regulated above the rated value. The research carried out as well as the results obtained can be used in the design, optimization and tuning of such types of drive systems.

  5. Variable Speed Wind Turbine Based on Multiple Generators Drive-Train Configuration

    Deng, Fujin; Chen, Zhe

    2010-01-01

    A variable speed wind turbine is presented in this paper, where multiple permanent magnet synchronous generators (MPMSGs) drive-train configuration is employed in the wind turbine. A cascaded multilevel converter interface based on the MPMSGs is developed to synthesize a desired high ac sinusoidal...... reduce the fluctuation of the electromagnetic torque sum and results in a good performance for the MPMSGs structure. The simulation study is conducted using PSCAD/EMTDC, and the results verify the feasibility of this variable speed wind turbine based on multiple generators drive-train configuration....... output voltage, which could be directly connected to the grids. What is more, such arrangement has been made so that the output ac voltage having a selected phase angle difference among the stator windings of multiple generators. A phase angle shift strategy is proposed in this paper, which effectively...

  6. High-speed low-power voltage-programmed driving scheme for AMOLED displays

    A new voltage-programmed driving scheme named the mixed parallel addressing scheme is presented for AMOLED displays, in which one compensation interval can be divided into the first compensation frame and the consequent N −1 post-compensation frames without periods of initialization and threshold voltage detection. The proposed driving scheme has the advantages of both high speed and low driving power due to the mixture of the pipeline technology and the threshold voltage one-time detection technology. Corresponding to the proposed driving scheme, we also propose a new voltage-programmed compensation pixel circuit, which consists of five TFTs and two capacitors (5T2C). In–Zn–O thin-film transistors (IZO TFTs) are used to build the proposed 5T2C pixel circuit. It is shown that the non-uniformity of the proposed pixel circuit is considerably reduced compared with that of the conventional 2T1C pixel circuit. The number of frames (N) preserved in the proposed driving scheme are measured and can be up to 35 with the variation of the OLED current remaining in an acceptable range. Moreover, the proposed voltage-programmed driving scheme can be more valuable for an AMOLED display with high resolution, and may also be applied to other compensation pixel circuits. (paper)

  7. Development of Permanent Magnet Reluctance Motor Suitable for Variable-Speed Drive for Electric Vehicle

    Sakai, Kazuto; Takahashi, Norio; Shimomura, Eiji; Arata, Masanobu; Nakazawa, Yousuke; Tajima, Toshinobu

    Regarding environmental and energy issues, increasing importance has been placed on energy saving in various systems. To save energy, it would be desirable if the total efficiency of various types of equipment were increased.Recently, a hybrid electric vehicle (HEV) and an electric vehicle (EV) have been developed. The use of new technologies will eventually lead to the realization of the new- generation vehicle with high efficiency. One new technology is the variable-speed drive over a wide range of speeds. The motor driving systems of the EV or the HEV must operate in the variable-speed range of up to 1:5. This has created the need for a high-efficiency motor that is capable of operation over a wide speed range. In this paper, we describe the concept of a novel permanent magnet reluctance motor (PRM) and discuss its characteristics. We developed the PRM, which has the capability of operating over a wide speed range with high efficiency. The PRM has a rotor with a salient pole, which generates magnetic anisotropy. In addition, the permanent magnets embedded in the rotor core counter the q-axis flux by the armature reaction. Then, the power density and the power factor increase. The PRM produces reluctance torque and torque by permanent magnet (PM) flux. The reluctance torque is 1 to 2 times larger than the PM torque. When the PRM operates over a constant-power speed range, the field component of the current will be regulated to maintain a constant voltage. The output power of the developed PRM is 8 to 250kW. It is clarified that the PRM operates at a wide variable-speed range (1:5) with high efficiency (92-97%). It is concluded that the PRM has high performance over a wide constant-power speed range. In addition, the PRM is constructed using a small PM, so that we can solve the problem of cost. Thus, the PRM is a superior machine that is suited for variable-speed drive applications.

  8. Data-based Speed-limit-respecting Eco-driving System

    Suzdaleva, Evgenia; Nagy, Ivan

    2014-01-01

    Roč. 44, č. 1 (2014), s. 253-264. ISSN 0968-090X R&D Projects: GA TA ČR TA01030123 Institutional support: RVO:67985556 Keywords : eco-driving * fuel consumption * recommended speed * recursive estimation * quadratic optimal control * dynamic programming Subject RIV: BC - Control Systems Theory Impact factor: 2.818, year: 2014 http://library.utia.cas.cz/separaty/2014/AS/suzdaleva-0427942.pdf

  9. Optimal motion planning with the half-car dynamical model for autonomous high-speed driving

    Jeon, Jeong hwan; Cowlagi, Raghvendra V.; Peters, Steven C.; Karaman, Sertac; Frazzoli, Emilio; Tsiotras, Panagiotis; Iagnemma, Karl

    2013-01-01

    We discuss an implementation of the RRT* optimal motion planning algorithm for the half-car dynamical model to enable autonomous high-speed driving. To develop fast solutions of the associated local steering problem, we observe that the motion of a special point (namely, the front center of oscillation) can be modeled as a double integrator augmented with fictitious inputs. We first map the constraints on tire friction forces to constraints on these augmented inputs, which provides instantane...

  10. The universal quantum driving force to speed up a quantum computation -- The unitary quantum dynamics

    Miao, Xijia

    2011-01-01

    It is shown in the paper that the unitary quantum dynamics in quantum mechanics is the universal quantum driving force to speed up a quantum computation. This assertion supports strongly in theory that the unitary quantum dynamics is the fundamental and universal principle in nature. On the other hand, the symmetric structure of Hilbert space of a composite quantum system is the quantum-computing resource that is not owned by classical computation. A new quantum-computing speedup theory is se...

  11. Variable Speed Wind Turbine Based on Multiple Generators Drive-Train Configuration

    Deng, Fujin; Chen, Zhe

    2010-01-01

    A variable speed wind turbine is presented in this paper, where multiple permanent magnet synchronous generators (MPMSGs) drive-train configuration is employed in the wind turbine. A cascaded multilevel converter interface based on the MPMSGs is developed to synthesize a desired high ac sinusoidal output voltage, which could be directly connected to the grids. What is more, such arrangement has been made so that the output ac voltage having a selected phase angle difference among the stator w...

  12. Feed drive simulation for the prediction of the tool path follow up in High Speed Machining

    Prévost, David; Lartigue, Claire

    2010-01-01

    This paper deals with an advanced modeling of the feed drives of a five axis machine tool within the context of High Speed Machining. The management of the multi axes as well as high velocities causes problems to the set machine tool - Numerical Controller throughout the trajectory execution process. As a result, many errors are introduced during machining all process long affecting the surface quality. The paper aims at modeling the feed drive dynamics during trajectory follow-up including the current, the velocity and position loops as well as the feed forward terms, which characterize classical drives on actual HSM machines. It concerns translational axes as well as rotary axes. A procedure of identification is implemented. Performances of the model are assessed by the comparison between simulated tool paths to the real one. Experimental verifications of the virtual axis model are detailed for three and five axis trajectories presenting various types of geometrical discontinuities.

  13. Energy efficiency high speed drives with magnetic bearings; Energieeffizienz durch schnell drehende, magnetgelagerte Antriebe

    Kroll, Matthias [LEViTEC GmbH, Lahnau (Germany)

    2011-07-01

    In modern purification plans the contamination of the wastewater are biologically removed by supplying oxygen. The clarifier is ventilated by compressors around the clock and approximately 60% of the total energy consumption is used for that. It enables a great opportunity for saving energy. This contribution shows that the use of magnetic centrifugal compressors with high-speed drives leads to significant reduction of energy consumption. In addition, the drive is, due to contact free the magnetic bearings, practically wear- and maintenance-free. By the use of integrated sensors in the magnetic bearings a continuous monitoring of the compressor is implemented. Consequently this drive concept provides not only more efficiency and less energy consumption, but also leads to a higher plant availability. (orig.)

  14. Combinatorial Optimization Method for Operation of Pumping Station with Adjustable Blade and Variable Speed Based on Experimental Optimization of Subsystem

    Yi Gong; Jilin Cheng

    2014-01-01

    A decomposition-dynamic programming aggregation method based on experimental optimization for subsystem was proposed to solve mathematical model of optimal operation for single pumping station with adjustable blade and variable speed. Taking minimal daily electric cost as objective function and water quantity pumped by units as coordinated variable, this model was decomposed into several submodels of daily optimal operation with adjustable blade and variable speed for single pump unit which w...

  15. Optimizing the driving scheme of a self-actuated atomic force microscope probe for high-speed applications

    We investigate the optimum driving scheme of a dynamic atomic force microscope with a self-actuated probe for high-speed applications by performing numerical simulations. We compare the recently developed methods such as Q-control, dynamic PID control, and modified Q-control methods to the standard tapping mode by considering scan speed and peak transient forces. In addition, the effects of driving frequency and set-point amplitude on the maximum achievable scan speed for the same probe-sample system are discussed. We find that the scan speed can be increased significantly at the expense of increased peak transient forces. -- Highlights: → Driving schemes of a dynamic AFM are examined to achieve the highest scan speed. → Q-control provides the highest scan speed with increased transient forces. → Off-resonance tapping is preferable unless transient forces can be ignored. → False error signal generation methods provide a slight improvement.

  16. High-speed low-power voltage-programmed driving scheme for AMOLED displays

    Xingheng, Xia; Weijing, Wu; Xiaofeng, Song; Guanming, Li; Lei, Zhou; Lirong, Zhang; Miao, Xu; Lei, Wang; Junbiao, Peng

    2015-12-01

    A new voltage-programmed driving scheme named the mixed parallel addressing scheme is presented for AMOLED displays, in which one compensation interval can be divided into the first compensation frame and the consequent N -1 post-compensation frames without periods of initialization and threshold voltage detection. The proposed driving scheme has the advantages of both high speed and low driving power due to the mixture of the pipeline technology and the threshold voltage one-time detection technology. Corresponding to the proposed driving scheme, we also propose a new voltage-programmed compensation pixel circuit, which consists of five TFTs and two capacitors (5T2C). In-Zn-O thin-film transistors (IZO TFTs) are used to build the proposed 5T2C pixel circuit. It is shown that the non-uniformity of the proposed pixel circuit is considerably reduced compared with that of the conventional 2T1C pixel circuit. The number of frames (N) preserved in the proposed driving scheme are measured and can be up to 35 with the variation of the OLED current remaining in an acceptable range. Moreover, the proposed voltage-programmed driving scheme can be more valuable for an AMOLED display with high resolution, and may also be applied to other compensation pixel circuits. Project supported by the State Key Development Program for Basic Research of China (No. 2015CB655000) the National Natural Science Foundation of China (Nos. 61204089, 61306099, 61036007, 51173049, U1301243), and the Fundamental Research Funds for the Central Universities (Nos. 2013ZZ0046, 2014ZZ0028).

  17. FPGA implementation of adaptive ANN controller for speed regulation of permanent magnet stepper motor drives

    This paper presents a novel adaptive artificial neural network (ANN) controller, which applies on permanent magnet stepper motor (PMSM) for regulating its speed. The dynamic response of the PMSM with the proposed controller is studied during the starting process under the full load torque and under load disturbance. The effectiveness of the proposed adaptive ANN controller is then compared with that of the conventional PI controller. The proposed methodology solves the problem of nonlinearities and load changes of PMSM drives. The proposed controller ensures fast and accurate dynamic response with an excellent steady state performance. Matlab/Simulink tool is used for this dynamic simulation study. The main contribution of this work is the implementation of the proposed controller on field programmable gate array (FPGA) hardware to drive the stepper motor. The driver is built on FPGA Spartan-3E Starter from Xilinx. Experimental results are presented to demonstrate the validity and effectiveness of the proposed control scheme.

  18. Neuro-fuzzy speed tracking control of traveling-wave ultrasonic motor drives using direct pulse width modulation

    Chau, KT; Chung, SW

    2002-01-01

    The traveling-wave ultrasonic motor (TUSM) drive offers many distinct advantages but suffers from severe system nonlinearities and parameter variations especially during speed control. This paper presents a new speed tracking control system for the TUSM drive, which newly incorporates neuro-fuzzy control and direct pulse width modulation to solve the problem of nonlinearities and variations. Increasingly, the proposed control system is digitally implemented by a low-cost digital signal proces...

  19. Neuro-Fuzzy Speed Tracking Control of Traveling-Wave Ultrasonic Motor Drives Using Direct Pulsewidth Modulation

    Chau, KT; Chung, SW; Chan, CC

    2003-01-01

    The traveling-wave ultrasonic motor (TWUM) drive offers many distinct advantages but suffers from severe system nonlinearities and parameter variations, especially during speed control. This paper presents a new speed tracking control system for the TWUM drive, which newly incorporates neuro-fuzzy control and direct pulsewidth modulation to solve the problem of nonlinearities and variations. The proposed control system is digitally implemented by a low-cost digital-signal-processor-based micr...

  20. Commissioning of 30 kVA variable-speed, direct-drive wind power plant

    Yildirim, Deniz

    Most wind turbines in service today employ induction generators together with a step-up mechanical gear so that the operational speed is close to the synchronous speed of two or four-pole generators. Because of the torque-speed characteristic of induction generators, the range of speed change is rather small; therefore, the operational speed can be considered to be nearly constant. Mechanical gears are subject to wear and tear, reduce reliability of the drive train and add to its weight. The maximum power that can be extracted from wind varies with its speed. Therefore, a direct-drive system, where a wind turbine is directly coupled to the generator shaft, is desirable along with a variable-speed operation. The variable-speed, direct-drive train described in this thesis consists of a lowspeed, permanent-magnet generator (60 to 120rpm), a resonant rectifier and a pulsewidth-modulated inverter. It supplies 30 kVA/20kW apparent/real power to the utility system at leading and unity power factors for a given DC link voltage. The amplitude and phase (leading, unity) of the AC current delivered to the utility system are controllable and the voltage/current wave forms at the point of common coupling satisfy standard IEEE-519. The overall efficiency of the drive train is about 83% (excluding the generator), whereby the rectifier has an efficiency of 86% and the inverter efficiency is around 95%. Using two different approaches (computer-aided and three-voltmeter methods), the losses of inductors are measured for the frequency range of 0 to 6 kHz. Measurement errors of both methods are less than 10% when measuring a few watts. The AC resistance increase of a Litz-wire inductor without a core is smallest among all of the inductors being tested. Stranding of individual (uninsulated) wires to obtain a flexible cable results in more losses than using a solid cable having the same cross-sectional area as that of a stranded cable. Nonsinusoidal voltages and currents in a power

  1. 400-MW adjustable-speed pumped-storage hydraulic power plant

    Kita, E. [Kansai Electric Power Co. Inc., Osaka (Japan); Bando, A.; Kuwabara, T. [Hitachi, Ltd., Tokyo (Japan)

    1995-02-01

    The performance of the 400 MW adjustable-speed pumped-storage hydraulic power plant of Okawachi Power Station, Kansai Electric Power Co., Inc., Japan is outlined. The plant adopts a cycloconverter for an exciter, and uses selectively one of three real power control modes such as fixed-frequency excitation, synchronous speed control and slip-phase control according to internal phase angles. The plant also adopts the operation mode giving priority to quick response to output commands, and the stator frequency detecting mode giving priority to response to power systems. The plant maintains an AFC capacity of {plus_minus}80 MW during pumping operation, and satisfies the intended performance requirements in both generating and pumping modes. The overcurrent and overvoltage protection systems of which functions were ascertained to be effective through power system tests, are used to eliminate side effects due to use of the cycloconverter for an exciter. The specific transient phenomenon analysis system is also used for supporting maintenance works. 5 refs., 12 figs., 2 tabs.

  2. Speed Sensorless Vector Control of Induction Motor Drive with PI and Fuzzy Controller

    R. Gunabalan

    2015-02-01

    Full Text Available This paper directed the speed-sensorless vector control of induction motor drive with PI and fuzzy controllers.  Natural observer with fourth order state space model is employed to estimate the speed and rotor fluxes of the induction motor. The formation of the natural observer is similar to and as well as its attribute is identical to the induction motor. Load torque adaptation is provided to estimate the torque and rotor speed is estimated from the load torque, rotor fluxes and stator currents. There is no direct feedback in natural observer and also observer gain matrix is absent. Both the induction motor and the observer are characterized by state space model. Simple fuzzy logic controller and conventional PI controllers are used to control the speed of the induction motor in closed loop. MATLAB simulations are made with PI and fuzzy controllers and the performance of fuzzy controller is better than PI controller in view of torque ripples. The simulation results are obtained for various running conditions to exhibit the suitability of this method for sensorless vector control. Experimental results are provided for natual observer based sensorless vector control with conventional PI controller.

  3. Variable-Speed Induction Motor Drives for Aircraft Environmental Control Compressors

    Mildice, J. W.; Hansen, I. G.; Schreiner, K. E.; Roth, M. E.

    1996-01-01

    New, more-efficient designs for aircraft jet engines are not capable of supplying the large quantities of bleed air necessary to provide pressurization and air conditioning for the environmental control systems (ECS) of the next generation of large passenger aircraft. System analysis and engineering have determined that electrically-driven ECS can help to maintain the improved fuel efficiencies; and electronic controllers and induction motors are now being developed in a NASA/NPD SBIR Program to drive both types of ECS compressors. Previous variable-speed induction motor/controller system developments and publications have primarily focused on field-oriented control, with large transient reserve power, for maximum acceleration and optimum response in actuator and robotics systems. The application area addressed herein is characterized by slowly-changing inputs and outputs, small reserve power capability for acceleration, and optimization for maximum efficiency. This paper therefore focuses on the differences between this case and the optimum response case, and shows the development of this new motor/controller approach. It starts with the creation of a new set of controller requirements. In response to those requirements, new control algorithms are being developed and implemented in an embedded computer, which is integrated into the motor controller closed loop. Buffered logic outputs are used to drive the power switches in a resonant-technology, power processor/motor-controller, at switching/resonant frequencies high enough to support efficient high-frequency induction motor operation at speeds up to 50,000-RPA

  4. Sensorless Rotor-Field Oriented Controlled Induction Motor Drive with Particle Swarm Optimization Algorithm Speed Controller Design Strategy

    Yung-Chang Luo; Zhi-Sheng Ke; Ying-Piao Kuo

    2014-01-01

    A sensorless rotor-field oriented control induction motor drive with particle swarm optimization algorithm speed controller design strategy is presented. First, the rotor-field oriented control scheme of induction motor is established. Then, the current-and-voltage serial-model rotor-flux estimator is developed to identify synchronous speed for coordinate transformation. Third, the rotor-shaft speed on-line estimation is established applying the model reference adaptive system method based on...

  5. A low-power high-speed driving circuit for spatial light modulators

    朱明皓; 朱从义; 李文江; 张耀辉

    2012-01-01

    This paper describes the design and test of a novel custom driving circuit for multi-quantum-well (MQW) spatial light modulators (SLMs).Unlike previous solutions,we integrated all blocks in one chip to synchronize the control logic circuit and the driving circuits.Single-slope digital-to-analog converters (DACs) inside each pixel are not adopted because it is difficult to eliminate capacitor mismatch.64 column-shared 8-bit resistorstring DACs are utilized to provide programmable output voltages from 0.5 to 3.8 V.They are located on the top of 64 × 64 driving pixels tightly to match each other with several dummies.Each DAC performs its conversion in 280 ns and draws 80 μA.For a high speed data transfer rate,the system adopts a 2-stage shift register that operates at 50 MHz and the modulating rate achieves 50 K frames/s while dissipating 302 mW from a 5-V supply.The die is fabricated in a 0.35μm CMOS process and its area is 5.5 × 7 mm2.

  6. Direct Torque Control of Four Switch Three Phase Inverter fed Induction Motor Sensorless Speed Drive

    Mohamed K Metwally

    2014-10-01

    Full Text Available This paper presents sensorless speed control of induction motor (IM using four switch three phase inverter (FSTPI with direct torque and flux control (DTFC. The proposed sensorless DTFC system consists of an adaptive observer of rotor flux to accurately estimate stator resistance and speed simultaneously, without affecting drive performances. The switching technique for DTFC of IM using FSTPI in low power application is based on the principle of similarity between FSTPI and SSTPI (six switch three phase inverter, where the αβ plan is divided into 6 sectors and the formation of the voltage space vector is done in the same way as for SSTPI by using effective (mean vectors. This approach allows using the well-known established switching table of SSTPI for FSTPI. The simulation results indicates that the sensorless speed control of FSTPI fed IM with DTFC and adaptive observer provides accurate estimate, good trajectory tracking with different dynamics performance. The experimental results verify the effectiveness of the proposed method at different operating points.

  7. Type-2 fuzzy logic control based MRAS speed estimator for speed sensorless direct torque and flux control of an induction motor drive.

    Ramesh, Tejavathu; Kumar Panda, Anup; Shiva Kumar, S

    2015-07-01

    In this research study, a model reference adaptive system (MRAS) speed estimator for speed sensorless direct torque and flux control (DTFC) of an induction motor drive (IMD) using two adaptation mechanism schemes are proposed to replace the conventional proportional integral controller (PIC). The first adaptation mechanism scheme is based on Type-1 fuzzy logic controller (T1FLC), which is used to achieve high performance sensorless drive in both transient as well as steady state conditions. However, the Type-1 fuzzy sets are certain and unable to work effectively when higher degree of uncertainties presents in the system which can be caused by sudden change in speed or different load disturbances, process noise etc. Therefore, a new Type-2 fuzzy logic controller (T2FLC) based adaptation mechanism scheme is proposed to better handle the higher degree of uncertainties and improves the performance and also robust to various load torque and sudden change in speed conditions, respectively. The detailed performances of various adaptation mechanism schemes are carried out in a MATLAB/Simulink environment with a speed sensor and speed sensorless modes of operation when an IMD is operating under different operating conditions, such as, no-load, load and sudden change in speed, respectively. To validate the different control approaches, the system also implemented on real-time system and adequate results are reported for its validation. PMID:25887841

  8. LC-filter Resonance Cancellation with DPWM Inverters in Adjustable Speed Drives

    Vadstrup, Casper; Wang, Xiongfei; Blaabjerg, Frede

    2015-01-01

    inverter and filter. Instead of abruptly clamp in one of the inverter legs and cause resonance in the filter. This method will charge or discharge the filter capacitor before clamping, this way the capacitor current is zero, and the capacitor voltage is equal to the average inverter voltage. Thereby, no...

  9. An EMC Evaluation of the Use of Unshielded Motor Cables in AC Adjustable Speed Drive Applications

    Hanigovszki, Norbert; Poulsen, J.; Spiazzi, G.;

    2004-01-01

    -phase applications the occurrence of common-mode voltage is inherent due to asymmetrical output pulses. As a result, for electromagnetic compatibility (EMC) reasons, in most applications shielded cables are used between the inverter and the motor, implying high installation costs. The present paper discusses the use...... of cheaper, unshielded cables. A new method for measuring electromagnetic interference (EMI) from unshielded cables is proposed and measurement results are presented. The level of EMI is evaluated in different situations: without an output filter, with a classical LC output filter and with an...

  10. Two Switch Adjustable-Speed Drive with Single-Phase Induction Machine

    Chomát, Miroslav; Lipo, T.

    Blacksburg, VA: National Science Foundation Engineering research Center, 2000, s. 381-385. [2000 CPES Power Electronics Seminar at Virginia Tech. Blacksburg, VA (US), 17.09.2000-19.09.2000] R&D Projects: GA MŠk ME 332 Grant ostatní: NSF(US) 9820434 Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  11. SPEED CONTROL OF PMBLDC DRIVE WITH GATE CONTROL METHOD USING CONVENTIONAL AND FUZZY CONTROLLER

    T.V.NARMADHA,

    2010-11-01

    Full Text Available The paper presents simulation results of fuzzy logic and conventional proportional integral controller for the sensorless speed control of permanent magnet brushless dc (PMBLDC motor using Gate control method. Although conventional PI controllers are widely used in the industry due to its simple control structure and ease of implementation, these controllers pose difficulties under the conditions of nonlinearity, load disturbances and parametric variations. Moreover PI controllers require precise linear mathematical models. In the paper, the performance of the permanent magnet brushless dc motor drive is examined with the aid of the fuzzy logic controller. The fuzzy logic controller shows improved performance compared to the conventional PI speed controller. The module of the Three Phase inverter system controlled Permanent magnet Brushless DC motor is simulated using PI and Fuzzy Logic Controller and implemented in closed loop model. . By simulation, the characteristics of the PMBLDCM system are investigated. THD analysis for the methods is presented. The simulation results indicate FLC has improved performance.

  12. Application of modern control theory to variable-speed drive. Gendai seigyo riron no kudo system eno oyo

    Tanisaka, A.; Yano, K.; Umida, H. (Fuji Electric Co. Ltd., Tokyo (Japan))

    1991-10-10

    Application of a modern control theory to drive systems for industrial facilities was reviewed. On a modern control theory, an observer, LQI control (integral optimum regulator), model following control, and adaptive identification were discussed briefly. The following were given as application examples of a modern control theory to practical facilities, the control for depressing impact drop in mill driving for steel rolling, the control for depressing axial torsional vibration in motor connected with load through a low stiffness axis, the control for depressing tension vibration developed in steel plates during cold rolling, the autotuning of parameters, and the instantaneous speed detection in combination of mean speed detection, disturbance torque observer and instantaneous speed calculation. In addition, as new trials for the drive systems, parametrization of three-freedom control systems and adaptive control in vector control were discussed. 9 refs., 21 figs., 1 tab.

  13. Establishing force and speed training targets for lumbar spine high-velocity, low-amplitude chiropractic adjustments*

    Owens, Edward F.; Hosek, Ronald S.; Sullivan, Stephanie G.B.; Russell, Brent S.; Mullin, Linda E.; Dever, Lydia L.

    2016-01-01

    Objective: We developed an adjusting bench with a force plate supporting the lumbar portion to measure loads transmitted during lumbar manual adjustment. It will be used to provide force-feedback to enhance student learning in technique labs. The study goal is to define the learning target loads and speeds, with instructors as expert models. Methods: A total of 11 faculty members experienced in teaching Gonstead technique methods performed 81 simulated adjustments on a mannequin on the force plate. Adjustments were along 9 lumbopelvic “listings” at 3 load levels: light, normal, and heavy. We analyzed the thrusts to find preload, peak load, duration, and thrust rate. Results: Analysis of 891 thrusts showed wide variations between doctors. Peak loads ranged from 100 to 1400 N. All doctors showed clear distinctions between peak load levels, but there was overlap between high and low loads. Thrust rates were more uniform across doctors, averaging 3 N/ms. Conclusion: These faculty members delivered a range of thrusts, not unlike those seen in the literature for high velocity, low amplitude manipulation. We have established at least minimum force and speed targets for student performance, but more work must be done to create a normative adjustment to guide refinement of student learning. PMID:26600272

  14. Using Artificial Neural Networks for Energy Regulation Based Variable-speed Electrohydraulic Drive

    XU Ming; JIN Bo; YU Yaxin; SHEN Haikuo; LI Wei

    2010-01-01

    In the energy regulation based varibable-speed electrohydraulic drive system, the supply energy and the demanded energy, which will affect the control performance greatly, are crucial. However, they are hard to be obtained via conventional methods for some reasons. This paper tries to a new route: the definitive numerical values of the supply energy and the demanded energy are not required, except for their relationship which is called energy state. A three-layer back propagation(BP) neural network was built up to act as an energy analysis unit to deduce the energy state. The neural network has three inputs: the reference displacement, the actual displacement of cylinder rod and the system flowrate supply. The output of the neural network is energy state. A Chebyshev type II filter was designed to calculate the cylinder speed for the estimation of system flowrate supply. The training and testing samples of neural network were collected by the system accurate simulation model. After off-line training, the neural network was tested by the testing data. And the testing result demonstrates that the designed neural network was successful. Then, the neural network acts as the energy analysis unit in real-time experiments of cylinder position control, where it works efficiently under square-wave and sine-wave reference displacement. The experimental results validate its feasibility and adaptability. Only a position sensor and some pressure sensors, which are cheap and have quick dynamic response, are necessary for the system control. And the neural network plays the role of identifying the energy state.

  15. Gear Design Effects on the Performance of High Speed Helical Gear Trains as Used in Aerospace Drive Systems

    Handschuh, R.; Kilmain, C.; Ehinger, R.; Sinusas, E.

    2013-01-01

    The performance of high-speed helical gear trains is of particular importance for tiltrotor aircraft drive systems. These drive systems are used to provide speed reduction / torque multiplication from the gas turbine output shaft and provide the necessary offset between these parallel shafts in the aircraft. Four different design configurations have been tested in the NASA Glenn Research Center, High Speed Helical Gear Train Test Facility. The design configurations included the current aircraft design, current design with isotropic superfinished gear surfaces, double helical design (inward and outward pumping), increased pitch (finer teeth), and an increased helix angle. All designs were tested at multiple input shaft speeds (up to 15,000 rpm) and applied power (up to 5,000 hp). Also two lubrication, system-related, variables were tested: oil inlet temperature (160 to 250 degF) and lubricating jet pressure (60 to 80 psig). Experimental data recorded from these tests included power loss of the helical system under study, the temperature increase of the lubricant from inlet to outlet of the drive system and fling off temperatures (radially and axially). Also, all gear systems were tested with and without shrouds around the gears. The empirical data resulting from this study will be useful to the design of future helical gear train systems anticipated for next generation rotorcraft drive systems.

  16. Combined Flux Observer With Signal Injection Enhancement for Wide Speed Range Sensorless Direct Torque Control of IPMSM Drives

    Blaabjerg, Frede; Andreescu, G.-D.; Pitic, C.I.;

    2008-01-01

    This paper proposes a motion-sensorless control system using direct torque control with space vector modulation for interior permanent magnet synchronous motor (IPMSM) drives, for wide speed range operation, including standstill. A novel stator flux observer with variable structure uses a combined...

  17. Practical Wide-speed-range Sensorless Control System for Permanent Magnet Reluctance Synchronous Motor Drives via Active Flux Model

    Ancuti, Mihaela Codruta; Tutelea, Lucian; Andreescu, Gheorghe-Daniel;

    2014-01-01

    This article introduces a control strategy to obtain near-maximum available torque in a wide speed range with sensorless operation via the active flux concept for permanent magnet-reluctance synchronous motor drives. A new torque dq current reference calculator is proposed, with reference torque...

  18. DEVELOPMENT OF OPTIMUM SPEED DIAGRAMS FOR SMALL MOVEMENT OF AN ACTUATING DEVICE OF AС ELECTRIC DRIVE-WITH ELASTIC SHAFTING

    Dobrobaba Y. P.

    2013-10-01

    Full Text Available In this article we describe the optimum speed diagram of moving actuating device of АС electric drive with elastic shafting. Parameters, conditions of existence and dependence of the duration of the cycle from the angle of rotation of actuating device are defined as well

  19. Effects of fatigue on simulated high speed driving for prolonged periods

    Javier Ferrero; Alejandra Hervás; Cristina Civera; Francisco Tortosa

    2011-01-01

    Some evidences show that fatigue, that is one of the main effects of prolonged driving, can be more evident on elderly people. This work describes a study on the effects of prolonged driving using a driving simulator within a group of individuals older than 55 years. These individuals underwent medical and psychological examinations before and after the driving experience: on the one hand, Blood Pressure and PulseOximetry were monitored and they took the Driver-Test. Preliminary results sugge...

  20. Effects of fatigue on simulated high speed driving for prolonged periods

    Javier Ferrero

    2011-09-01

    Full Text Available Some evidences show that fatigue, that is one of the main effects of prolonged driving, can be more evident on elderly people. This work describes a study on the effects of prolonged driving using a driving simulator within a group of individuals older than 55 years. These individuals underwent medical and psychological examinations before and after the driving experience: on the one hand, Blood Pressure and PulseOximetry were monitored and they took the Driver-Test. Preliminary results suggest a decreasing performance after driving, especially affecting decision-making capacity

  1. Dynamic Modeling of Adjustable-Speed Pumped Storage Hydropower Plant: Preprint

    Muljadi, E.; Singh, M.; Gevorgian, V.; Mohanpurkar, M.; Havsapian, R.; Koritarov, V.

    2015-04-06

    Hydropower is the largest producer of renewable energy in the U.S. More than 60% of the total renewable generation comes from hydropower. There is also approximately 22 GW of pumped storage hydropower (PSH). Conventional PSH uses a synchronous generator, and thus the rotational speed is constant at synchronous speed. This work details a hydrodynamic model and generator/power converter dynamic model. The optimization of the hydrodynamic model is executed by the hydro-turbine controller, and the electrical output real/reactive power is controlled by the power converter. All essential controllers to perform grid-interface functions and provide ancillary services are included in the model.

  2. Swarming Speed Control for DC Permanent Magnet Motor Drive via Pulse Width Modulation Technique and DC/DC Converter

    A.S. Oshaba

    2013-05-01

    Full Text Available This study presents an approach for the speed control of a permanent magnet DC motor drive via Pulse Width Modulation (PWM technique and a DC/DC converter. The Particle Swarm Optimization (PSO technique is used to minimize a time domain objective function and obtain the optimal controller parameters. The performance of the proposed technique has been evaluated using various types of disturbances including load torque variations. Simulation results illustrate clearly the robustness of the controller and validity of the design technique for controlling the speed of permanent magnet motors.

  3. A Novel Adjustment Method for Shearer Traction Speed through Integration of T-S Cloud Inference Network and Improved PSO

    Lei Si

    2014-01-01

    Full Text Available In order to efficiently and accurately adjust the shearer traction speed, a novel approach based on Takagi-Sugeno (T-S cloud inference network (CIN and improved particle swarm optimization (IPSO is proposed. The T-S CIN is built through the combination of cloud model and T-S fuzzy neural network. Moreover, the IPSO algorithm employs parameter automation adjustment strategy and velocity resetting to significantly improve the performance of basic PSO algorithm in global search and fine-tuning of the solutions, and the flowchart of proposed approach is designed. Furthermore, some simulation examples are carried out and comparison results indicate that the proposed method is feasible, efficient, and is outperforming others. Finally, an industrial application example of coal mining face is demonstrated to specify the effect of proposed system.

  4. Swarming Speed Control for DC Permanent Magnet Motor Drive via Pulse Width Modulation Technique and DC/DC Converter

    A.S. Oshaba; E.S. Ali

    2013-01-01

    This study presents an approach for the speed control of a permanent magnet DC motor drive via Pulse Width Modulation (PWM) technique and a DC/DC converter. The Particle Swarm Optimization (PSO) technique is used to minimize a time domain objective function and obtain the optimal controller parameters. The performance of the proposed technique has been evaluated using various types of disturbances including load torque variations. Simulation results illustrate clearly the robustness of the co...

  5. Adjusting for car occupant injury liability in relation to age, speed limit, and gender-specific driver crash involvement risk.

    Keall, Michael; Frith, William

    2004-12-01

    It is well established that older drivers' fragility is an important factor associated with higher levels of fatal crash involvement for older drivers. There has been less research on age-related fragility with respect to the sort of minor injuries that are more common in injury crashes. This study estimates a quantity that is related to injury fragility: the probability that a driver or a passenger of that driver will be injured in crashes involving two cars. The effects of other factors apart from drivers' fragility are included in this measure, including the fragility of the passengers, the crashworthiness of cars driven, seatbelt use by the occupants, and characteristics of crashes (including configuration and impact speed). The car occupant injury liability estimates appropriately includes these factors to adjust risk curves by age, gender, and speed limit accounting for overrepresentation in crashes associated with fragility and these other factors. PMID:15545071

  6. Free-standing few-layered graphene oxide films: selective, steady and lasting permeation of organic molecules with adjustable speeds

    Huang, Tao; An, Qi; Luan, Xinglong; Zhang, Qian; Zhang, Yihe

    2016-01-01

    A variety of small molecules with diameters around 1 nm possess a range of functions, such as antibiotic, antimicrobic, anticoagulant, pesticidal and chemotherapy effects, making these molecules especially useful in various applications ranging from medical treatment to environmental microbiological control. However, the long-term steady delivery (release or permeation) of these small molecules with adjustable and controllable speeds has remained an especially challenging task. In this study, we prepared covalently cross-linked free-standing few-layered GO films using a layer-by-layer technique in combination with photochemical cross-linkages, and achieved a controlled release of positively charged, negatively charged, and zwitterionic small molecules with adjustable and controllable speeds. The steady delivery of the small molecule lasted up to 9 days. Other functionalities, such as graphene-enhanced Raman spectra and electrochemical properties that could also be integrated or employed in delivery systems, were also studied for our films. We expect the special molecular delivery properties of our films to lead to new possibilities in drug/fertilizer delivery and environmental microbiological control applications.A variety of small molecules with diameters around 1 nm possess a range of functions, such as antibiotic, antimicrobic, anticoagulant, pesticidal and chemotherapy effects, making these molecules especially useful in various applications ranging from medical treatment to environmental microbiological control. However, the long-term steady delivery (release or permeation) of these small molecules with adjustable and controllable speeds has remained an especially challenging task. In this study, we prepared covalently cross-linked free-standing few-layered GO films using a layer-by-layer technique in combination with photochemical cross-linkages, and achieved a controlled release of positively charged, negatively charged, and zwitterionic small molecules with

  7. Modulation of Premotor and Primary Motor Cortical Activity during Volitional Adjustments of Speed-Accuracy Trade-Offs.

    Thura, David; Cisek, Paul

    2016-01-20

    Recent work suggests that while animals decide between reaching actions, neurons in dorsal premotor (PMd) and primary motor (M1) cortex reflect a dynamic competition between motor plans and determine when commitment to a choice is made. This competition is biased by at least two sources of information: the changing sensory evidence for one choice versus another, and an urgency signal that grows over time. Here, we test the hypothesis that the urgency signal adjusts the trade-off between speed and accuracy during both decision-making and movement execution. Two monkeys performed a reaching decision task in which sensory evidence continuously evolves over the course of each trial. In different blocks, task timing parameters encouraged monkeys to voluntarily adapt their behavior to be either hasty or conservative. Consistent with our hypothesis, during the deliberation process the baseline and gain of neural activity in decision-related PMd (29%) and M1 cells (45%) was higher when monkeys applied a hasty policy than when they behaved conservatively, but at the time of commitment the population activity was similar across blocks. Other cells (30% in PMd, 30% in M1) showed activity that increased or decreased with elapsing time until the moment of commitment. Movement-related neurons were also more active after longer decisions, as if they were influenced by the same urgency signal controlling the gain of decision-related activity. Together, these results suggest that the arm motor system receives an urgency/vigor signal that adjusts the speed-accuracy trade-off for decision-making and movement execution. Significance statement: This work addresses the neural mechanisms that control the speed-accuracy trade-off in both decisions and movements, in the kinds of dynamic situations that are typical of natural animal behavior. We found that many "decision-related" premotor and motor neurons are modulated in a time-dependent manner compatible with an "urgency" signal that

  8. New possibilities with new technology: the Adjustable Speed Hydro (ASH) generator

    Generators with variable rotational speed can be the solution for the Norwegian power system. The technology is available and is already used abroad. As with all projects, investing in ASH must be based on economic profitability, where all advantages and disadvantages are considered, and on thorough techno-economic analyses. The article describes the fundamental principles of the ASH, its advantages, and discusses its possible installation in already existing power stations

  9. Modeling and Analysis of PI Controller Based Speed Control of Brushless DC Motor Drive.

    Mr.P.Nagasekhar Reddy

    2013-01-01

    The Brushless DC motors (BLDC) find widespread applications in domestic and industries due to their low and high power density and ease of speed control. To accomplish desired level of performance the motor requires suitable speed controllers. In case of permanent magnet Brushless DC motors, usually control of speed is reached by using proportional integral (PI) controller. Although the conventional PI controllers are widely used in the industry due to their simple control structure and ease ...

  10. Gravitational search algorithm based tuning of a PI speed controller for an induction motor drive

    Abd Ali, Jamal; Hannan, M. A.; Mohamed, Azah

    2016-03-01

    Proportional-integral (PI)-controller is very useful for controlling speed and mechanical load variables for the three-phase induction motor (TIM) operation. However, the conventional PI-controller has a very exhaustive trial and error procedure for obtaining it is parameters. In this paper, PI speed controller has been improved in it is design technique to suite TIM by utilizing a gravitational search algorithm (GSA) optimization technique. The mean absolute error (MAE) of the speed response has been used as an objective function. An optimal GSA based PI speed controller (GSA-PI) objective function is also employed to tune and minimize the MAE for developing the performance of the TIM in terms of changes speed and mechanical load. This experiment use space vector pulse width modulation (SVPWM) technique to create pulse width modulation for switching devices for three phase bridge inverter. Results obtained from the GSA-PI speed controller are compared with those obtained through particle swarm optimization (PSO) to validate the developed controller. Then it has been proved that the robustness of the GSA-PI speed controller is far better than that of the1 PSO controller in all tested cases in terms of damping capability and transient response under different mechanical loads and speeds.

  11. Emission characteristics of nonmethane hydrocarbons from private cars and taxis at different driving speeds in Hong Kong

    Guo, H.; Zou, S. C.; Tsai, W. Y.; Chan, L. Y.; Blake, D. R.

    2011-05-01

    Vehicular emissions are the major sources of a number of air pollutants including nonmethane hydrocarbons (NMHCs) in urban area. The emission composition and emission factors of NMHCs from vehicles are currently lacking in Hong Kong. In this study, speciation and emission factors of NMHCs emitted from gasoline-fuelled private cars and liquefied petroleum gas (LPG)-fuelled taxis at different driving speeds were constructed using a chassis dynamometer. Large variations in the contributions of individual NMHC species to total emission were observed for different private cars at different driving speeds. The variations of individual NMHC emissions were relatively smaller for taxis due to their relatively homogeneous year of manufacture and mileages. Incomplete combustion products like ethane, ethene and propene were the major component of both types of vehicles, while unburned fuel component was also abundant in the exhausts of private cars and taxis (i.e. i-pentane and toluene for private car, and propane and butanes for taxi). Emission factors of major NMHCs emitted from private cars and taxis were estimated. High emission factors of ethane, n-butane, i/ n-pentanes, methylpentanes, trimethylpentanes, ethene, propene, i-butene, benzene, toluene and xylenes were found for private cars, whereas propane and i/ n-butanes had the highest values for taxis. By evaluating the effect of vehicular emissions on the ozone formation potential (OFP), it was found that the contributions of olefinic and aromatic hydrocarbons to OFP were higher than that from paraffinic hydrocarbons for private car, whereas the contributions of propane and i/ n-butanes were the highest for taxis. The total OFP value was higher at lower speeds (≤50 km h -1) for private cars while a minimum value at driving speed of 100 km h -1 was found for taxis. At the steady driving speeds, the total contribution of NMHCs emitted from LPG-fuelled taxis to the OFP was much lower than that from gasoline

  12. The Effect of Rotor Cruise Tip Speed, Engine Technology and Engine/Drive System RPM on the NASA Large Civil Tiltrotor (LCTR2) Size and Performance

    Robuck, Mark; Wilkerson, Joseph; Maciolek, Robert; Vonderwell, Dan

    2012-01-01

    A multi-year study was conducted under NASA NNA06BC41C Task Order 10 and NASA NNA09DA56C task orders 2, 4, and 5 to identify the most promising propulsion system concepts that enable rotor cruise tip speeds down to 54% of the hover tip speed for a civil tiltrotor aircraft. Combinations of engine RPM reduction and 2-speed drive systems were evaluated. Three levels of engine and the drive system advanced technology were assessed; 2015, 2025 and 2035. Propulsion and drive system configurations that resulted in minimum vehicle gross weight were identified. Design variables included engine speed reduction, drive system speed reduction, technology, and rotor cruise propulsion efficiency. The NASA Large Civil Tiltrotor, LCTR, aircraft served as the base vehicle concept for this study and was resized for over thirty combinations of operating cruise RPM and technology level, quantifying LCTR2 Gross Weight, size, and mission fuel. Additional studies show design sensitivity to other mission ranges and design airspeeds, with corresponding relative estimated operational cost. The lightest vehicle gross weight solution consistently came from rotor cruise tip speeds between 422 fps and 500 fps. Nearly equivalent results were achieved with operating at reduced engine RPM with a single-speed drive system or with a two-speed drive system and 100% engine RPM. Projected performance for a 2025 engine technology provided improved fuel flow over a wide range of operating speeds relative to the 2015 technology, but increased engine weight nullified the improved fuel flow resulting in increased aircraft gross weights. The 2035 engine technology provided further fuel flow reduction and 25% lower engine weight, and the 2035 drive system technology provided a 12% reduction in drive system weight. In combination, the 2035 technologies reduced aircraft takeoff gross weight by 14% relative to the 2015 technologies.

  13. Mechanical fault diagnostics for induction motor with variable speed drives using Adaptive Neuro-fuzzy Inference System

    Ye, Z. [Department of Electrical & amp; Computer Engineering, Queen' s University, Kingston, Ont. (Canada K7L 3N6); Sadeghian, A. [Department of Computer Science, Ryerson University, Toronto, Ont. (Canada M5B 2K3); Wu, B. [Department of Electrical & amp; Computer Engineering, Ryerson University, Toronto, Ont. (Canada M5B 2K3)

    2006-06-15

    A novel online diagnostic algorithm for mechanical faults of electrical machines with variable speed drive systems is presented in this paper. Using Wavelet Packet Decomposition (WPD), a set of feature coefficients, represented with different frequency resolutions, related to the mechanical faults is extracted from the stator current of the induction motors operating over a wide range of speeds. A new integrated diagnostic system for electrical machine mechanical faults is then proposed using multiple Adaptive Neuro-fuzzy Inference Systems (ANFIS). This paper shows that using multiple ANFIS units significantly reduces the scale and complexity of the system and speeds up the training of the network. The diagnostic algorithm is validated on a three-phase induction motor drive system, and it is proven to be capable of detecting rotor bar breakage and air gap eccentricity faults with high accuracy. The algorithm is applicable to a variety of industrial applications where either continuous on-line monitoring or off-line fault diagnostics is required. (author)

  14. Experimental Performance Evaluation of a High Speed Permanent Magnet Synchronous Motor and Drive for a Flywheel Application at Different Frequencies

    Nagorny, Aleksandr S.; Jansen, Ralph H.; Kankam, M. David

    2007-01-01

    This paper presents the results of an experimental performance characterization study of a high speed, permanent magnet motor/generator (M/G) and drive applied to a flywheel module. Unlike the conventional electric machine the flywheel M/G is not a separated unit; its stator and rotor are integrated into a flywheel assembly. The M/G rotor is mounted on a flywheel rotor, which is magnetically levitated and sealed within a vacuum chamber during the operation. Thus, it is not possible to test the M/G using direct load measurements with a dynamometer and torque transducer. Accordingly, a new in-situ testing method had to be developed. The paper describes a new flywheel M/G and drive performance evaluation technique, which allows the estimation of the losses, efficiency and power quality of the flywheel high speed permanent magnet M/G, while working in vacuum, over wide frequency and torque ranges. This method does not require any hardware modification nor any special addition to the test rig. This new measurement technique is useful for high-speed applications, when applying an external load is technically difficult.

  15. Circuit Regulates Speed Of dc Motor

    Weaver, Charles; Padden, Robin; Brown, Floyd A., Jr.

    1990-01-01

    Driving circuit regulates speed of small dc permanent-magnet motor in tape recorder. Two nested feedback loops maintain speed within 1 percent of constant value. Inner loop provides coarse regulation, while outer loop removes most of variation in speed that remains in the presence of regulation by the inner loop. Compares speed of motor with commanded speed and adjusts current supplied to motor accordingly.

  16. Driving behaviour responses to a moose encounter, automatic speed camera, wildlife warning sign and radio message determined in a factorial simulator study.

    Jägerbrand, Annika K; Antonson, Hans

    2016-01-01

    In a driving simulator study, driving behaviour responses (speed and deceleration) to encountering a moose, automatic speed camera, wildlife warning sign and radio message, with or without a wildlife fence and in dense forest or open landscape, were analysed. The study consisted of a factorial experiment that examined responses to factors singly and in combination over 9-km road stretches driven eight times by 25 participants (10 men, 15 women). The aims were to: determine the most effective animal-vehicle collision (AVC) countermeasures in reducing vehicle speed and test whether these are more effective in combination for reducing vehicle speed; identify the most effective countermeasures on encountering moose; and determine whether the driving responses to AVC countermeasures are affected by the presence of wildlife fences and landscape characteristics. The AVC countermeasures that proved most effective in reducing vehicle speed were a wildlife warning sign and radio message, while automatic speed cameras had a speed-increasing effect. There were no statistically significant interactions between different countermeasures and moose encounters. However, there was a tendency for a stronger speed-reducing effect from the radio message warning and from a combination of a radio message and wildlife warning sign in velocity profiles covering longer driving distances than the statistical tests. Encountering a moose during the drive had the overall strongest speed-reducing effect and gave the strongest deceleration, indicating that moose decoys or moose artwork might be useful as speed-reducing countermeasures. Furthermore, drivers reduced speed earlier on encountering a moose in open landscape and had lower velocity when driving past it. The presence of a wildlife fence on encountering the moose resulted in smaller deceleration. PMID:26600095

  17. Using LDR as Sensing Element for an External Fuzzy Controller Applied in Photovoltaic Pumping Systems with Variable-Speed Drives

    Geraldo Neves De A. Maranhão

    2015-09-01

    Full Text Available In the present paper, a fuzzy controller applied to a Variable-Speed Drive (VSD for use in Photovoltaic Pumping Systems (PVPS is proposed. The fuzzy logic system (FLS used is embedded in a microcontroller and corresponds to a proportional-derivative controller. A Light-Dependent Resistor (LDR is used to measure, approximately, the irradiance incident on the PV array. Experimental tests are executed using an Arduino board. The experimental results show that the fuzzy controller is capable of operating the system continuously throughout the day and controlling the direct current (DC voltage level in the VSD with a good performance.

  18. Explicit Generalized Predictive Algorithms for Speed Control of PMSM Drives Fast Explicit Form with Field Weakening and Current Limitation

    Belda, Květoslav; Vošmik, D.

    Vienna: AIT Austrian Institute of Technology GmbH, 2013, s. 2833-2838. ISBN 978-1-4799-0224-8. ISSN 1553-572X. [IECON 2013. Vienna (AT), 10.11.2013-13.11.2013] R&D Projects: GA ČR(CZ) GAP102/11/0437 Institutional support: RVO:67985556 Keywords : PMSM drives * speed control * field weakening * current limitation * Generalized Predictive Control Subject RIV: BC - Control Systems Theory http://library.utia.cas.cz/separaty/2013/AS/belda-0398603.pdf

  19. DAC to Mitigate the Effect of Periodic Disturbances on Drive Train using Collective Pitch for Variable Speed Wind Turbine

    Imran, Raja Muhammad; Hussain, Dil Muhammad Akbar; Soltani, Mohsen

    scheme to mitigate the effect of 3p flicker on drive train. 5MW wind turbine of the National Renewable Laboratories (NREL) is used as research object and results are simulated in MATLAB/Simulink. We designed the controller based on linearized model of the wind turbine generated for above rated wind speed...... and then tested its performance on the nonlinear model of wind turbine. We have shown a comparison of the results for proportional-integral(PI) and proposed DAC controller tested on nonlinear model of wind turbine. Result shows that our proposed controller shows better mitigation of flicker generated...

  20. A hybrid inverter/cycloconverter-based variable-speed three-phase induction motor drive for single-phase inputs

    Chen, C. [Ford Motor Co., Dearborn, MI (United States). Scientific Research Lab.; Divan, D.M.; Novotny, D.W. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Electrical and Computer Engineering

    1995-05-01

    This paper presents a simple converter topology for driving a three-phase induction motor with a single-phase ac supply. Using only two active switches and a Triac, the converter can start the motor with high starting torque and low input current, and can bring the motor up to full speed using a very cost-effective, single-phase field-oriented control strategy. The converter supplies balanced output voltages at rated frequency with virtually no output distortion and with very high input power factor. In this paper, the capability contours for different speed ranges and various operating modules are addressed; the trade-offs between output torque, torque, ripple, input current distortion, and inverter rating are also explained, and the proposed control approaches are supported by simulation and test results.

  1. A Class of Speed Sensorless Sliding Mode Observers for Direct Torque Controlled Induction Motor Drives

    Lascu, Cristian; Boldea, Ion; Blaabjerg, Frede

    A family of speed-sensorless sliding-mode observers for induction motors has been developed. Three topologies have been investigated in order to determine their feasibility, parameter sensitivity and practical applicability. The salient feature of all schemes is that they do not require the rotor...... speed adaptation, that is, they are inherently sensorless observers. The most versatile is a dual-reference-frame observer. The other two schemes, implemented in stator frame and rotor frame, respectively, are simpler and are insensitive to detuning some of the motor parameters. Main theoretical aspects...

  2. Explicit Generalized Predictive Control of Speed and Position of PMSM Drives

    Belda, Květoslav; Vošmik, D.

    2016-01-01

    Roč. 63, č. 6 (2016), s. 3889-3896. ISSN 0278-0046 Institutional support: RVO:67985556 Keywords : current limitation * field weakening * motion control * permanent magnet synchronous motors * position control * predictive control * speed control Subject RIV: BC - Control Systems Theory Impact factor: 6.498, year: 2014 http://library.utia.cas.cz/separaty/2016/AS/belda-0457259.pdf

  3. Comparative Study between PI and FUZZY Logic Speed Controller in Vector Controlled PMSM Drive

    Kaushik Jash

    2014-04-01

    Full Text Available This paper is concerned with vector control of permanent magnet synchronous motor (PMSM using two different type of speed controller, one is PI controller and another is FUZZY logic controller. Although Proportional Integral Controller usually preferred as a speed controller due to its fixed gain and integral time constant but the performance of PI controller is affected by parameter variation, such as load changing, speed variation etc. In PI controller THD of the stator phase current is more and torque ripple also more. To avoid this problem here we used FUZZY logic controller. In this paper the mathematical model of PMSM, using the powerful simulation modeling capabilities of Matlab/Simulink is implemented. The entire PMSM control system is divided into several independent functional modules such as PMSM body module, inverter module and coordinate transformation module and Sinusoidal pulse width modulation (SPWM production module and so on. Here we used two loops, one is outer loop known as speed control loop, another is inner loop called current loop. we can analyzed a variety of simulation waveforms and it provide an effective means for the analysis and design of the PMSM control system.

  4. 高频斩波串级调速系统功率因数的分析与计算%Analysis and Calculation for Power Factor of the High-frequency Chopped Wave Cascade Speed Control Drive System

    张军伟; 王兵树; 万军; 甄亚

    2011-01-01

    相对于变频调速系统,高频斩波串级调速系统具有节能效率高、结构简单、技术难度小等优点,在交流调速中得到了广泛应用.但和传统串级调速一样,该系统的严重缺点之一是功率因数低,而且随着负载变化和速度的调节,系统功率因数的变化范围很大.所以有必要准确分析计算其功率因数.本文介绍了高频斩波串级调速系统的工作原理,在此基础上提出了一种新的计算高频斩波串级调速系统功率因数的简化算法,总结了影响高频斩波串级调速系统功率因数的几大因素,最后通过建立试验系统进行验证,证实该算法的可靠性,对实际工程设计有实用价值.%Compared with frequency conversion speed control, high-frequency chopped wave cascade speed control drive system has such advantages as good efficiency on energy saving, simple structure and little technical difficulty,etc. So, it is widely used in AC governing speed field. However, as the traditional cascade speed governing drive, low power factor is the same overt weakness to the high-frequency chopped wave cascade speed control drive system. In addition, the power factor could change in a large range with the speed adjustment and changing load. So it is very necessary to analyse and calculate the power factor accurately. A compact algorithm to calculate the power factor of chopped wave cascade speed control drive system is put forward on the basic of introduction of the radical theory about it. A few of factors impacting on the power factor of chopper cascade speed control drive system are summed up. At last, A simulation validating system is founded, and which prove that the algorithm is reliable and practical on engineering design.

  5. An enhanced Z-source inverter topology-based permanent magnet brushless DC motor drive speed control

    Geno Peter, P.; Rajaram, M.

    2015-08-01

    In this paper, an enhanced Z-source inverter (ZSI) is introduced for controlling the speed of permanent magnet brushless DC motor (PMBLDCM) drive. It is the extension of the conventional ZSI and the elements used in the circuit are the same as those of the conventional ZSI, except that the position of Inverter Bridge and diode would be exchanged from the classical circuit diagram. This exchanged circuit avoids the startup path of the inrush current and hence reduces the inrush current and improves the motor efficiency. Different modes of enhanced ZSI are studied with PMBLDCM. The voltage polarity of Z-source capacitors in the proposed circuit is the same as that of the input voltage polarity. Furthermore, to get the same voltage boost, the capacitor voltage stress is reduced to a significant extent. The speed control capability of the proposed brushless DC motor drive is compared with that of the conventional ZSI. The proposed ZSI is implemented in MATLAB/Simulink working platform and the output performance is evaluated. Also, the performance of voltage ratio is analysed both by simulation and mathematical models. All these analyses are known to express the innovative features of the proposed system.

  6. Structure of 15-Level Sub-Module Cascaded H-Bridge Inverter for Speed Control of AC Drive Applications

    R. Uthirasamy

    2015-02-01

    Full Text Available This paper deals with the implementation of a single phase 15-level Sub-Multilevel Cascaded H-Bridge Inverter (SMCHBI for variable speed industrial drive applications. It consists of sub-multilevel modules and H-bridge inverter configuration. Sub-multilevel switches synthesize stepped DC link voltage and current from the DC sources. H-bridge inverter switches renovate stepped DC link voltage and current into sinusoidal waveform. Compared with conventional Cascaded Multilevel Inverter (CMLI, the proposed system employs the reduced number of power switches, DC sources and gate driver requirements. The proposed system not only reduces the overall system cost but also reduces the voltage stress across the inverter switches. The proposed system does not required additional resonant soft switching circuits for Zero Voltage Switching (ZVS of inverter. In the proposed method, variable frequency method is adopted for the speed control of industrial induction motor drives. A prototype model of 15-level SMCHB is developed and the performance of the systems is validated experimentally.

  7. Social interactions dominate speed control in driving natural flocks toward criticality

    Bialek, William; Giardina, Irene; Mora, Thierry; Pohl, Oliver; Silvestri, Edmondo; Viale, Massimiliano; Walczak, Aleksandra

    2013-01-01

    Flocks of birds exhibit a remarkable degree of coordination and collective response. It is not just that thousands of individuals fly, on average, in the same direction and at the same speed, but that even the fluctuations around the mean velocity are correlated over long distances. Quantitative measurements on flocks of starlings, in particular, show that these fluctuations are scale-free, with effective correlation lengths proportional to the linear size of the flock. Here we construct models for the joint distribution of velocities in the flock that reproduce the observed local correlations between individuals and their neighbors, as well as the variance of flight speeds across individuals, but otherwise have as little structure as possible. These minimally structured, or maximum entropy models provide quantitative, parameter-free predictions for the spread of correlations throughout the flock, and these are in excellent agreement with the data. These models are mathematically equivalent to statistical phy...

  8. SPEED CONTROL OF PMBLDC DRIVE WITH GATE CONTROL METHOD USING CONVENTIONAL AND FUZZY CONTROLLER

    T.V.NARMADHA,; T. Thyagarajan

    2010-01-01

    The paper presents simulation results of fuzzy logic and conventional proportional integral controller for the sensorless speed control of permanent magnet brushless dc (PMBLDC) motor using Gate control method. Although conventional PI controllers are widely used in the industry due to its simple control structure and ease of implementation, these controllers pose difficulties under the conditions of nonlinearity, load disturbances and parametric variations. Moreover PI controllers require pr...

  9. Type-1 and Type-2 Fuzzy Logic and Sliding-Mode Based Speed Control of Direct Torque and Flux Control Induction Motor Drives - A Comparative Study

    Ramesh, Tejavathu; Panda, A. K.; Kumar, S. Shiva

    2013-08-01

    In this research study, the performance of direct torque and flux control induction motor drive (IMD) is presented using five different speed control techniques. The performance of IMD mainly depends on the design of speed controller. The PI speed controller requires precise mathematical model, continuous and appropriate gain values. Therefore, adaptive control based speed controller is desirable to achieve high-performance drive. The sliding-mode speed controller (SMSC) is developed to achieve continuous control of motor speed and torque. Furthermore, the type-1 fuzzy logic speed controller (T1FLSC), type-1 fuzzy SMSC and a new type-2 fuzzy logic speed controller are designed to obtain high performance, dynamic tracking behaviour, speed accuracy and also robustness to parameter variations. The performance of each control technique has been tested for its robustness to parameter uncertainties and load disturbances. The detailed comparison of different control schemes are carried out in a MATALB/Simulink environment at different speed operating conditions, such as, forward and reversal motoring under no-load, load and sudden change in speed.

  10. Recent developments and benefits of high-speed PWM inverter-fed induction-motor drive for gas filtration in nuclear power plants

    This paper will discuss new developments relating to the use of a high-speed inverter-fed induction-motor drive for gas filtration of the main gas circulator compartment in nuclear power stations. Conventional drives use low speed induction motors which operate from fixed supply frequencies of either 50 Hz or 60 Hz. Operating speeds are essentially constant and for a 2-pole, 50 Hz machine the speed is 2750 r/min approximately. Due to the low operating speed, the sizes of both the motor and the impeller are rather large. For this type of drive, fixed speed operation results in high capital and operational costs. The system environmental conditions of very dry helium are severe and the operating temperature and pressure are both high for this type of motor. The expected system life is 40 years approximately and does not allow maintenance. In operation the motor is fully submerged in the process gas. This contribution will present some of the results of a development program carried out by two Howden Group companies on a high-speed drive. (Author)

  11. High-Speed Current dq PI Controller for Vector Controlled PMSM Drive

    Mohammad Marufuzzaman

    2014-01-01

    Full Text Available High-speed current controller for vector controlled permanent magnet synchronous motor (PMSM is presented. The controller is developed based on modular design for faster calculation and uses fixed-point proportional-integral (PI method for improved accuracy. Current dq controller is usually implemented in digital signal processor (DSP based computer. However, DSP based solutions are reaching their physical limits, which are few microseconds. Besides, digital solutions suffer from high implementation cost. In this research, the overall controller is realizing in field programmable gate array (FPGA. FPGA implementation of the overall controlling algorithm will certainly trim down the execution time significantly to guarantee the steadiness of the motor. Agilent 16821A Logic Analyzer is employed to validate the result of the implemented design in FPGA. Experimental results indicate that the proposed current dq PI controller needs only 50 ns of execution time in 40 MHz clock, which is the lowest computational cycle for the era.

  12. Performance Analysis of DTC-SVM Sliding Mode Controllers-Based Parameters Estimator of Electric Motor Speed Drive

    Fatma Ben Salem

    2014-01-01

    Full Text Available This paper is concerned with a framework which unifies direct torque control space vector modulation (DTC-SVM and variable structure control (VSC. The result is a hybrid VSC-DTC-SVM controller design which eliminates several major limitations of the two individual controls and retains merits of both controllers. It has been shown that obtained control laws are very sensitive to variations of the stator resistance, the rotor resistance, and the mutual inductance. This paper discusses the performances of adaptive controllers of VSC-DTC-SVM monitored induction motor drive in a wide speed range and even in the presence of parameters uncertainties and mismatching disturbances. Better estimations of the stator resistance, the rotor resistance, and the mutual inductance yield improvements of induction motor performances using VSC-DTC-SVM, thereby facilitating torque ripple minimization. Simulation results verified the performances of the proposed approach.

  13. The use of variable speed drives for cost-effective energy savings in South African mine cooling systems

    Highlights: • Energy analysis of 20 South African mine cooling systems. • Energy savings and feasibility calculated for large-scale variable speed drive implementation. • An annual electricity saving of 144,721 MW h (32.2%) and CO2 emission reduction of 132 Mton can be realised. • Pump and fan application found more viable than chiller application. • Pilot implementation study shows pump electricity savings of 29.9%. - Abstract: An industrial energy efficiency improvement through the introduction of modern technology is an important demand-side management initiative. Cooling systems on South African mines have been identified as large electricity consumers. There is significant potential for energy efficiency improvement by the widespread introduction of variable speed drive (VSD) technology. An energy audit was conducted on 20 large mine cooling systems and potential savings and feasibility indicators were calculated. A pilot implementation study was also done on one mine to experimentally validate the estimated savings. In this paper, the results of the audit, the potential savings and the pilot study results are presented. It is shown that large-scale implementation of VSDs on mine cooling system pumps and fans is economically viable. A total annual electrical energy saving of 144,721 MW h, or 32.2%, can be achieved. An annual cost saving of US$6,938,148 and CO2 emissions reduction of 132 Mton is possible. The implementation of VSDs on mine chiller compressors will also result in large energy savings, but is not economically feasible at present. Results of the pilot study indicate an electricity savings of 29.9%. The results are important to decision makers and indicate the significant impact that widespread VSD usage on mine cooling systems can have on South African mine sustainability

  14. Temperature and Light Control of Three phase Induction Motor Speed Drive by PIC

    Barsoum, Nader

    2010-06-01

    PIC is a family of Harvard architecture microcontrollers made by Microchip Technology, derived from the PIC1640 originally developed by General Instrument's Microelectronics Division. The name PIC initially referred to "Peripheral Interface Controller". PICs are popular with the developers and the hobbyists due to their low cost, wide availability, large user base, extensive collection of application notes, free development tools, and serial programming (and re-programming with flash memory) capability. In modern days, PIC microcontrollers are used in the industrial world to control many types of equipment, ranging from consumer to specialized devices. They have replaced older types of controllers, including microprocessors. Also, there is a growing need for off-line support of a computer's main processor. The demand is going to grow with more equipment uses more intelligence. In the engineering field for instance, PIC has brought a very positive impact in designing an automation control system and controlling industrial machineries. Accordingly, this paper shows the change in the motor speed by the use of PIC in accordance to the light and level of temperature. The project focuses on programming the PIC by embedded software that detects the temperature and light signals and send it to 3 phase induction motor of 240 volt. A theoretical analysis and the practical approach in achieving this work goal have proved that PIC plays an important role in the field of electronics control.

  15. Effects of priming exercise on the speed of adjustment of muscle oxidative metabolism at the onset of moderate-intensity step transitions in older adults.

    De Roia, Gabriela; Pogliaghi, Silvia; Adami, Alessandra; Papadopoulou, Christina; Capelli, Carlo

    2012-05-15

    Aging is associated with a functional decline of the oxidative metabolism due to progressive limitations of both O(2) delivery and utilization. Priming exercise (PE) increases the speed of adjustment of oxidative metabolism during successive moderate-intensity transitions. We tested the hypothesis that such improvement is due to a better matching of O(2) delivery to utilization within the working muscles. In 21 healthy older adults (65.7 ± 5 yr), we measured contemporaneously noninvasive indexes of the overall speed of adjustment of the oxidative metabolism (i.e., pulmonary Vo(2) kinetics), of the bulk O(2) delivery (i.e., cardiac output), and of the rate of muscle deoxygenation (i.e., deoxygenated hemoglobin, HHb) during moderate-intensity step transitions, either with (ModB) or without (ModA) prior PE. The local matching of O(2) delivery to utilization was evaluated by the ΔHHb/ΔVo(2) ratio index. The overall speed of adjustment of the Vo(2) kinetics was significantly increased in ModB compared with ModA (P ModA (P < 0.05), suggesting an improved O(2) delivery. Our data are compatible with the hypothesis that, in older adults, PE, prior to moderate-intensity exercise, beneficially affects the speed of adjustment of oxidative metabolism due to an acute improvement of the local matching of O(2) delivery to utilization. PMID:22422668

  16. High- Speed railway lines in Germany: Experience in Tunnelling in Karstic Geology and Discussion oF Tunnel Driving Methods

    Rudolf Pottler

    2004-01-01

    In the course of Deutsche Bahn's new high - speed railway line between Nuremberg and Ingolstadt, a number of tunnels are being constructed, with a total length of about 15 km. One of the longest tunnel is the 7,250 m long Irlahüll tunnel.The tunnel was driven in karst geology. It was not expected that karst phenomena would be so widespread. This forced client, designer and contractor to take a new approach to the project. Different tools were developed to handle the problems on site. Additional site investigations had to be performed to identify karst phenomena in the vicinity of the tunnel. For validating the stability and serviceability of the tunnel, a new way of defining the probability of failure of the construction had to be found. Based on the experience of the tunnel driving at the high - speed railway line in Germany between Nuremberg and Ingolstadt, two different methods of tunnelling are discussed: Drill and blast ( New Austrian Tunnelling Method: NATM) and the use of tunnel boring machines (TBM).

  17. Minimization and identification of conducted emission bearing current in variable speed induction motor drives using PWM inverter

    A Ramachandran; M Channa Reddy; Ranjan Moodithaya

    2008-10-01

    The recent increase in the use of speed control of ac induction motor for variable speed drive using pulse width modulation (PWM) inverter is due to the advent of modern power electronic devices and introduction of microprocessors. There are many advantages of using ac induction motor for speed control applicatons in process and aerospace industries, but due to fast switching of the modern power electronic devices, the parasitic coupling produces undesirable effects. The undesirable effects include radiated and conducted electromagnetic interference (EMI) which adversely affect nearby computers, electronic/electrical instruments and give rise to the flow of bearing current in the induction motor. Due to the flow of bearing current in the induction motor, electrical discharge machining takes place in the inner race of the bearing which reduces the life of the bearing. In high power converters and inverters, the conducted and radiated emissions become a major concern. In this paper, identification of bearing current due to conducted emission, the measurement of bearing current in a modified induction motor and to minimize the bearing current are discussed. The standard current probe, the standard line impedance stabilization network (LISN)), the electronics interface circuits are used to measure high frequency common mode current, bearing current and to minimize the conducted noise from the system. The LISN will prevent the EMI noise entering the system from the supply source by conductive methods, at the same time prevents the EMI generated if any due to PWM, fast switching in the system, will not be allowed to enter the supply line. For comparing the results with Federal Communications Commission (FCC) and Special Committee on Radio Interference (CISPR) standards, the graphs are plotted with frequency Vs, line voltage in $dB{_\\mu} V$, common mode voltage in $dB{_\\mu} V$ and the bearing current in $dB_{\\mu} A$ with out and with minimizing circuits.

  18. Correlation of prefrontal cortical activation with changing vehicle speeds in actual driving: a vector-based functional near-infrared spectroscopy study

    Kouji Yamamoto; Hideki Takahashi; Toshinori Kato

    2013-01-01

    Traffic accidents occur more frequently during deceleration than during acceleration. However, little is known about the relationship between brain activation and vehicle acceleration because it has been difficult to measure the brain activation of drivers while they drive. In this study, we measured brain activation during actual driving using vector-based functional near-infrared spectroscopy. Subjects decelerated from 100 to 50 km/h (speed reduction task) and accelerated from 50 to 100 km/...

  19. Space and time harmonics related problems and their mitigation for position and speed sensorless slip-ring induction motor drives applications

    Subhasis Nandi

    2008-10-01

    There have been renewed interests in slip-ring induction machines due to their increasing use in both grid connected and stand-alone wind power generation schemes. Despite the squirrel cage induction generators’ advantages of being brushless, low-cost, needing less maintenance and having inherent overload protection, the biggest advantage of variable-speed wound rotor induction machines is in its doubled energy capture. Also in high power induction motor drives such as static Kramer drives or static Scherbius drives use of wound rotor induction motors is a must. Thus it becomes necessary to measure the speed of the machine for closed loop control for such high performance drives. Recently, a sensorless position and speed estimation scheme was proposed for wound rotor wind power generator. In this paper, the limitation of the scheme caused by space and time harmonics have been investigated. Simulation results have been presented to explain the mechanism of the space and time harmonics caused distortion of current. Experimental results showing the deterioration of speed detection scheme at light load for a slip-ring induction motor have been presented. Finally, improvements have been applied experimentally to obtain better speed estimation.

  20. 同调式带转动的无级变速%Stepless Speed of Synchronous Adjusting Belt Drive

    邢荣胜; 赵华

    2002-01-01

    通过对国内目前广泛采用的v型带无级变速传动装置中存在的问题进行剖析,并根据实际需要,设计出一种结构简单,调速灵活,操作方便的同调式带传动无级变速装置.

  1. Chapter 18: Variable Frequency Drive Evaluation Protocol

    Romberger, J.

    2014-11-01

    An adjustable-speed drive (ASD) includes all devices that vary the speed of a rotating load, including those that vary the motor speed and linkage devices that allow constant motor speed while varying the load speed. The Variable Frequency Drive Evaluation Protocol presented here addresses evaluation issues for variable-frequency drives (VFDs) installed on commercial and industrial motor-driven centrifugal fans and pumps for which torque varies with speed. Constant torque load applications, such as those for positive displacement pumps, are not covered by this protocol. Other ASD devices, such as magnetic drive, eddy current drives, variable belt sheave drives, or direct current motor variable voltage drives, are also not addressed. The VFD is by far the most common type of ASD hardware. With VFD speed control on a centrifugal fan or pump motor, energy use follows the affinity laws, which state that the motor electricity demand is a cubic relationship to speed under ideal conditions. Therefore, if the motor runs at 75% speed, the motor demand will ideally be reduced to 42% of full load power; however, with other losses it is about 49% of full load power.

  2. Improvements in High Speed, High Resolution Dynamic Digital Image Correlation for Experimental Evaluation of Composite Drive System Components

    Kohlman, Lee W.; Ruggeri, Charles R.; Roberts, Gary D.; Handschuh, Robert Frederick

    2013-01-01

    Composite materials have the potential to reduce the weight of rotating drive system components. However, these components are more complex to design and evaluate than static structural components in part because of limited ability to acquire deformation and failure initiation data during dynamic tests. Digital image correlation (DIC) methods have been developed to provide precise measurements of deformation and failure initiation for material test coupons and for structures under quasi-static loading. Attempts to use the same methods for rotating components (presented at the AHS International 68th Annual Forum in 2012) are limited by high speed camera resolution, image blur, and heating of the structure by high intensity lighting. Several improvements have been made to the system resulting in higher spatial resolution, decreased image noise, and elimination of heating effects. These improvements include the use of a high intensity synchronous microsecond pulsed LED lighting system, different lenses, and changes in camera configuration. With these improvements, deformation measurements can be made during rotating component tests with resolution comparable to that which can be achieved in static tests

  3. Balanced Motions Realization for a Mechanical Regulators Free and Front-Wheel Drive Bicycle Robot Under Zero Forward Speed

    Yonghua Huang

    2013-08-01

    Full Text Available This paper focuses on a mechanical regulator free and front‐ wheel drive bicycle robot. We present a scheme to achieve the robotʹs track‐stand motion and circular motion under zero forward speed. In a situation where the robotʹs front‐bar is locked at 90 degrees, a kinetic constraint about the rotating rate of the front‐wheel and the yawing rate of the frame is derived. Using the constraint as a basis, we developed a simplified model of two independent velocities for the robot. The model suggests there is an under‐ actuated rolling angle in the system. Our control strategy originates from the under‐ actuated characteristics of the robot system. Concretely, we linearize the rolling angle of the frame and set the bicycle robot to regulate its tilting by rotating the front‐wheel. In the track‐stand motion, we control the position and the rotational rate of the front‐wheel; but in the circular motion, only the rotational rate of the front‐wheel is strictly regulated. Both simulations and physical experiments results show that our strategy is effective for achieving these two motions.

  4. Two-Phase Induction Motor Drives

    Gholam Reza Arab Markadeh

    2010-10-01

    Full Text Available The lack of variable-speed drives for two (single induction motor is a reality. This article attempts mainly to investigate the reasons for this lack of variable – speed drives. This paper deals with literature survey of various existing converter topologies, which have been proposed for adjustable speed single phase induction motor drives. Various converter topologies have been compared in this paper. Among these converter topologies, the adjustable frequency PWM inverter is the best choice for single-phase induction motor drives. However, adjustable-frequency drives have not been widely used with single-phase Induction motors. The open-loop constant V/F control law cannot be used with the single-phase induction motor drives as it is used with three phase motors. The variation of the operating frequency at lower speed range with constant load torque causes variation in motor's slip. A constant V/F control is suitable only over the upper speed range.

  5. Improvement of power system stability of an adjustable-speed pumped-storage generator/motor. Denryoku keito ni okeru kahensoku yosui hatsuden dendoki no keito anteido kojo ni kansuru kenkyu

    Michigami, T. (Tokyo Electric Power Co., Inc. (Japan)); Koyanagi, K. (Toshiba Corp., Tokyo (Japan))

    1994-02-20

    Recently, adjustable-speed pumped-storage generator/motor (adjustable-speed machine) is applied to power system as AFC adjusting force. This adjustable-speed machine has no problem on its stability and AC excitation control is carried out by the cycloconverter with speedy response since its being different from the conventional fixed-speed synchronous machine that the rotor speed becomes to adjustable. In this paper, aiming at the improvement of power system stability by using said adjustable-speed machine, the basic consideration on the rotor speed and reactive power control by AC excitation of the adjustable-speed machine; theoretical examination on the analysis model for analysing the system stability; analysis simulation results using two machine-pair infinite system for obtaining the basic properties of the improvement of power system stability; verification results on the effectiveness of improvement of power system stability as well as analysis model by simulative power transmission test are described. Further, the analysis simulation results on the effectiveness of improvement of power system stability by the models with the scale of practical system are reported. 11 refs., 15 figs., 9 tabs.

  6. Fuzzy Logic based Speed Control of a Six-Phase Series-Connected Two-Motor Drive System Feed from SVPWMVSI

    H. A. Hairik

    2008-01-01

    Full Text Available This paper presents a new topology for the control of a six-phase series-connectedtwo-motor drive system supplied from Space Vector Pulse Width Modulation (SVPWMVoltage Source Inverter (VSI. The two-motordrive system consists of a six-phase and athree-phase induction motors connected in series. These motors and the supply system havebeen analyzed to construct a field-orientedmodel for them. This model clearly shows thepossibility of independent of control of the two machines. A fuzzy logic based speed controller has been constructed and used to drive the two-motor in this work . The two-motor system, inverter system, and the fuzzy controller models are implemented and tested using Simulink/Matlab facilities. The presented results show the validity of the model to dowell for the sake of speed control under different operating conditions.

  7. Design and analysis of speed-sensorless robust stochastic L∞-induced observer for high-performance brushless DC motor drives with diminished torque ripple

    Highlights: ► A new sensorless BLDC motor drives based on L∞-induced observer has been proposed. ► A design and analysis of robust stochastic L∞-induced observer has been carried out. ► We present theoretical aspects of design for proposed, Kalman, sliding-mode methods. ► We compare three sensorless topologies from four aspects of simulation performance. ► Unique merit of proposed method makes it suitable for high-performance application. - Abstract: This paper aims to present an analysis and design of a high-performance speed-sensorless control scheme for a three-phase brushless DC (BLDC) motor drive by means of a novel observer technique in the induced L∞ norm setting, named robust stochastic L∞-induced observer, with the purpose of reducing torque ripple and increasing system robustness. The proposed observer is used for estimating the phase-to-phase trapezoidal back-electromotive-force (back-EMF) for the BLDC motor merely via utilizing measured line stator currents and voltages in such a way that by estimating the back-EMF, position and speed of the rotor is readily obtained. In contrast to the conventional back-EMF sensing methods, this strategy of utilized drive requires no filtering of current and voltage; furthermore, it does not suffer from any sensitivity to switching noises. Owing to that high-speed operation is vital for a motor, the varying input voltage method is used for realizing the minimization of commutation-torque-ripple in a parallel way to the proposed method since drive performance intensely degrades in this mode. Apart from analytic investigation of the proposed method, two other types of observers, namely, the sliding-mode observer and Kalman filter are compared with the proposed method for the aim of determining steady-state accuracy, dynamic performance, parameter and noise sensitivity, low-speed-operation performance, and computational complexity. Finally, the proposed system has been simulated in different operating

  8. Effects of excessive speeding and falling asleep while driving on crash injury severity in Ethiopia: a generalized ordered logit model analysis.

    Abegaz, Teferi; Berhane, Yemane; Worku, Alemayehu; Assrat, Abebe; Assefa, Abebayehu

    2014-10-01

    The severity of injury from vehicle crash is a result of a complex interaction of factors related to drivers' behavior, vehicle characteristics, road geometric and environmental conditions. Knowing to what extent each factor contributes to the severity of an injury is very important. The objective of the study was to assess factors that contribute to crash injury severity in Ethiopia. Data was collected from June 2012 to July 2013 on one of the main and busiest highway of Ethiopia, which extends from the capital Addis Ababa to Hawassa. During the study period a total of 819 road crashes was recorded and investigated by trained crash detectors. A generalized ordered logit/partial proportional odds model was used to examine factors that might influence the severity of crash injury. Model estimation result suggested that, alcohol use (Coef.=0.5565; p-value=0.017), falling asleep while driving (Coef.=1.3102; p-value=0.000), driving at night time in the absence of street light (Coef.=0.3920; p-value=0.033), rainfall (Coef.=0.9164; p-value=0.000) and being a minibus or vans (Coef.=0.5065; p-value=0.013) were found to be increased crash injury severity. On the other hand, speeding was identified to have varying coefficients for different injury levels, its highest effects on sever and fatal crashes. In this study risky driving behaviors (speeding, alcohol use and sleep/fatigue) were a powerful predictor of crash injury severity. Therefore, better driver licensing and road safety awareness campaign complimented with strict police enforcement can play a pivotal role to improve road safety. Further effort needed as well to monitor speed control strategies like; using the radar control and physical speed restraint measures (i.e., rumble strips). PMID:24866353

  9. A Sensorless Speed Control using Stator Ripple Currents for an Induction Motor Drive with Space Phasor PWM

    Mohapatra, KK; Gopakumar, K.; Baiju, MR; Murty, BV

    2004-01-01

    In the present paper a simple sensorless speed estimation scheme is presented, where the speed information is obtained from the motor phase current ripple. The scheme measures the stator current phasor deviation direction to determine the back EMF vector position during inverter zero vector switching states. This measurement of rotor flux position is done indirectly by computing the motor back EMF position which is orthogonal to the rotor flux position. The space vector PWM voltage output in ...

  10. 新型高速精密压力机传动机构研究%Research on new drive mechanism of a high-speed precision press

    柯尊芒; 鹿新建; 冯华伟; 王寒阳

    2013-01-01

    基于ADAMS动力学仿真软件,对卵形齿轮一曲柄滑块机构的新型高速精密压力机进行仿真研究,并与曲柄滑块机构的滑块位移、速度、加速度和驱动扭矩进行对比,有助于该型高速精密压力机的研发.%Based on ADAMS the oval gear-slider-crank mechanism of the new high-speed precision press was studied.The slider displacement,velocity,acceleration and driving torque were compared with the slider-crank mechanism.And this helps the development of the high-speed precision press

  11. Sensorless FOC Performance Improved with On-Line Speed and Rotor Resistance Estimator Based on an Artificial Neural Network for an Induction Motor Drive.

    Gutierrez-Villalobos, Jose M; Rodriguez-Resendiz, Juvenal; Rivas-Araiza, Edgar A; Martínez-Hernández, Moisés A

    2015-01-01

    Three-phase induction motor drive requires high accuracy in high performance processes in industrial applications. Field oriented control, which is one of the most employed control schemes for induction motors, bases its function on the electrical parameter estimation coming from the motor. These parameters make an electrical machine driver work improperly, since these electrical parameter values change at low speeds, temperature changes, and especially with load and duty changes. The focus of this paper is the real-time and on-line electrical parameters with a CMAC-ADALINE block added in the standard FOC scheme to improve the IM driver performance and endure the driver and the induction motor lifetime. Two kinds of neural network structures are used; one to estimate rotor speed and the other one to estimate rotor resistance of an induction motor. PMID:26131677

  12. Fault Tolerant Three-Phase AC Motor Drive Topologies:A Comparison of Features, Cost, and Limitations

    2005-01-01

    THE RELIABILITY of adjustables peed ac motor drives is an area of great interest for all members of the drives community and marketplace. This is particularly the case for the military, aerospace and automotive industries that are increasingly adopting variable speed drives in order to improve overall system efficiency and performance. There are certain safety critical applications such as steering, fuel pumps,

  13. SPEED CONTROL OF DC MOTOR WITH PIC 16F877

    İlhami ÇOLAK

    2005-02-01

    Full Text Available In this study, a PI controlled separately excited direct current (DC motor speed has been controlled using PIC 16F877 controller. In the PIC 16F877 programming as a PI controller, the speed of the motor is expected to follow the reference speed. Speed of the motor is measured by a tacho generator and then, the voltage applied to the motor is adjusted by a semiconductor power switch using pulse width modulation (PWM technique. Drive circuit was tested with 0.9 kW DC motor. Experimental results show that the drive circuit developed is very simple, useful, sensible, economical and flexible to apply for different applications.

  14. A Class of Speed-Sensorless Sliding-Mode Observers for High-Performance Induction Motor Drives

    Lascu, Christian; Boldea, Ion; Blaabjerg, Frede

    2009-01-01

    require the rotor speed adaptation, i.e., they are inherently sensorless observers. The most versatile and robust is a dual-reference-frame full-order flux observer. The other two schemes are flux observers implemented in stator frame and rotor frame, respectively. These are simpler than the first one and...

  15. Rotor-dynamic design aspects for a variable frequency drive based high speed cryogenic centrifugal pump in fusion devices

    Superconducting magnets of large size are inevitable for fusion devices due to high magnetic field requirements. Forced flow cooling of the superconducting magnets with high mass flowrate of the order ∼3 kg/s is required to keep superconducting magnets within its safe operational boundaries during various plasma scenarios. This important requirement can be efficiently fulfilled by employing high capacity and high efficiency cryogenic centrifugal pumps. The efficiency > 70% will ensure overall lower heat load to the cryoplant. Thermo-hydraulic design of cryogenic centrifugal pump revealed that to achieve the operational regime with high efficiency, the speed should be ∼ 10,000 revolutions per minute. In this regard, the rotor-dynamic design aspect is quite critical from the operational stability point of view. The rotor shaft design of the cryogenic pump is primarily an outcome of optimization between thermal heat-in leak at cryogenic temperature level from ambient, cryogenic fluid impedance and designed rotation speed of the impeller wheel. The paper describes the basic design related to critical speed of the rotor shaft, rotor whirl and system instability prediction to explore the ideal operational range of the pump from the system stability point of view. In the rotor-dynamic analysis, the paper also describes the Campbell plots to ensure that the pump is not disturbed by any of the critical speeds, especially while operating near the nominal and enhanced operating modes. (author)

  16. Robust optical speed tracking control of a current sensor less synchronous reluctance motor drive using a new sliding mode controller

    This paper describes the robust optimal incremental motion control of a current sensor less synchronous reluctance motor, which can be specified by any desired speed profile. The control scheme is a combination of conventional linear quadratic feed back control method and sliding mode control. A novel sliding switching surface is employed first, that makes the states of the synchronous reluctance motor follow the nominal trajectories (controlled by any type of nominal controller) when the motor parameter uncertainties and the disturbance load torque exist. The sliding mode controller has no reaching phase and produces small sliding mode control chattering. Then, using the above tracking controller, the well-known torque control schemes, maximum torque, constant current inductive axis control and maximum power factor control related to the synchronous reluctance motor are examined below and above the base speed. Finally the validity of our proposed control scheme is verified by computer simulation results

  17. Applied intelligent control of induction motor drives

    Chan, Tze Fun

    2011-01-01

    Induction motors are the most important workhorses in industry. They are mostly used as constant-speed drives when fed from a voltage source of fixed frequency. Advent of advanced power electronic converters and powerful digital signal processors, however, has made possible the development of high performance, adjustable speed AC motor drives.This book aims to explore new areas of induction motor control based on artificial intelligence (AI) techniques in order to make the controller less sensitive to parameter changes. Selected AI techniques are applied for different induction motor control s.

  18. Use of an expert system for the choice of variable speed drives; Application des techniques d`intelligence artificielle pour le choix des systemes d`entrainement a vitesse variable

    Chetate, B.; Khaldi, T.; Boudjennah, B.; Kara, C. [Institut National des Hydrocarbures et de la Chimie de Boumerdes (Algeria). Laboratoire des Economies d`Energie Electrique

    1998-06-01

    The electrical motors variable speed is a factor of energy saving. The interest of variable speed is justified by the fact that the investment is quickly redeemable. In this study, the authors present an expert system for the rational choice of variable speed drives (IES/VSD). This system allows to take into account the varieties of electrical motors, electronics converters and complex control systems. (authors) 12 refs.

  19. Correlation of prefrontal cortical activation with changing vehicle speeds in actual driving: a vector-based functional near-infrared spectroscopy study

    Kouji Yamamoto

    2013-12-01

    Full Text Available Traffic accidents occur more frequently during deceleration than during acceleration. However, little is known about the relationship between brain activation and vehicle acceleration because it has been difficult to measure the brain activation of drivers while they drive. In this study, we measured brain activation during actual driving using vector-based functional near-infrared spectroscopy. Subjects decelerated from 100 to 50 km/h (speed reduction task and accelerated from 50 to 100 km/h (speed increase task while driving on an expressway, in the daytime and at night. We examined correlations between average vehicle acceleration in each task and five hemodynamic indices: changes in oxygenated hemoglobin (ΔoxyHb, deoxygenated hemoglobin (ΔdeoxyHb, cerebral blood volume (ΔCBV, and cerebral oxygen exchange (ΔCOE; and the phase angle k (degrees derived from the other hemoglobin (Hb indices. ΔoxyHb and ΔCBV reflect changes in cerebral blood flow, whereas ΔdeoxyHb, ΔCOE, and k are related to variations in cerebral oxygen metabolism. Most of the resulting correlations with specific brain sites, for all the indices, appeared during deceleration rather than during acceleration. Faster deceleration resulted in greater increases in ΔdeoxyHb, ΔCOE, and k in the prefrontal cortex (r 0.4, p < 0.01, suggesting oxygen metabolism associated with transient ischemic changes. Our results suggest that vehicle deceleration requires more brain activation, focused in the prefrontal cortex, than does acceleration. From the standpoint of the indices used, we found that simultaneous analysis of multiple hemodynamic indices was able to detect not only the blood flow components of hemodynamic responses, but also more localized frontal lobe activation involving oxygen metabolism.

  20. Novel sensorless starting and low speed drive of cylindrical brushless DC motor using eddy current with un-known load; Uzudenryu wo riyoshita entogata brushless DC motor no futokutei fukaji ni okeru sensorless shidoho oyobi teisoku kudoho

    Tomita, M.; Doki, S.; Okuma, S. [Nagoya University, Nagoya (Japan); Yamaguchi, H. [The Aichi Electric Co. Ltd., Aichi (Japan)

    1998-04-01

    Sensorless starting and low speed drive of a cylindrical brushless DC motor with un-known load have been a difficult problem because an electromotive force does not arise enough at the starting and at low speeds and an inductance is constant irrespective of rotor position. In this paper, it is proposed to paste non-magnetic material and to measure a voltage of an opened phase to realize sensorless starting and low speed drives. The method is shown very feasible by experiments. 13 refs., 17 figs., 2 tabs.

  1. A high-speed multi-protocol quantum key distribution transmitter based on a dual-drive modulator

    Korzh, Boris; Houlmann, Raphael; Zbinden, Hugo

    2013-01-01

    We propose a novel source based on a dual-drive modulator that is adaptable and allows Alice to choose between various practical quantum key distribution (QKD) protocols depending on what receiver she is communicating with. Experimental results show that the proposed transmitter is suitable for implementation of the Bennett and Brassard 1984 (BB84), coherent one-way (COW) and differential phase shift (DPS) protocols with stable and low quantum bit error rate. This could become a useful component in network QKD, where multi-protocol capability is highly desirable.

  2. A Luenberger State Observer for Simultaneous Estimation of Speed and Rotor Resistance in sensorless Indirect Stator Flux Orientation Control of Induction Motor Drive

    Mabrouk Jouili

    2011-11-01

    Full Text Available The primary objective of this paper is to implement a sensorless indirect stator field oriented control (ISFOC of induction motor drive with rotor resistance tuning. Indeed, the proposed method for simultaneous rotor speed and rotor resistance estimation is based on Luenberger observer (LO. In order to estimate the rotor speed and the rotor resistance, an adaptive algorithm based on Lyapunov stability theory by using measured and estimated stator currents and estimated stator flux is proposed. The suggested control scheme, as a result, achieves a sound performance with computational complexity reduction obtained by using the analytical relation to determine the LO gain matrix. Again, the observer is simple and robust, when compared with the previously developed observers, and suitable for online implementation. For current regulation, however, this paper suggests a conventional Proportional-Integral (PI controller with feed-forward compensation terms in the synchronous frame. Owing to its advantages, an Integral-Proportional (IP controller is used for rotor speed regulation. The design, analysis, and implementation for a 3-kW induction motor are completely carried out using a dSpace DS 1104 digital signal processor (DSP based real-time data acquisition control (DAC system, and MATLAB/Simulink environment. Digital simulation and experimental results are presented to show the improvement in performance of the proposed algorithm.

  3. Comparative study of SVPWM (space vector pulse width modulation) and SPWM (sinusoidal pulse width modulation) based three phase voltage source inverters for variable speed drive

    We have performed comparative studies of Space Vector Pulse Width Modulation (SVPWM) and Sinusoidal Pulse Width Modulation (SPWM) techniques utilizing MATLAB tools. During these investigations, we carried out intensive simulations, comprehensively analyzed the obtained results and compared the harmonic density, power factor (PF), and switching losses of SVPWM and SPWM. It has been observed during investigations that if the switching frequency is high then losses due to harmonics are negligible, thus based on obtained results we suggested that the SVPWM technique is a more reliable solution. Because SVPWM utilizes DC bus voltage more efficiently, generates less Total Harmonic Distortion (THD) and has higher output quality it provides flexible control of output voltage and output frequency for Variable Speed Drive (VSD)

  4. Warp Drive: A New Approach

    Obousy, Richard

    2007-01-01

    Certain classes of higher dimensional models suggest that the Casimir Effect is a candidate for the cosmological constant. In this paper we demonstrate that a sufficiently advanced civilization could, in principal, manipulate the radius of the extra dimension to locally adjust the value of the cosmological constant. This adjustment could be tuned to generate an expansion/contraction of spacetime around a spacecraft creating an exotic form of field-propulsion. Due to the fact that spacetime expansion itself is not restricted by relativity, a faster-than-light 'warp drive' could be created. Calculations of the energy requirements of such a drive are performed and an 'ultimate' speed limit, based on the Planckian limits on the size of the extra dimensions is found.

  5. Stator insulation systems for medium voltage PWM drives fed motors

    This paper presents the partial results of a research project that studied the impact of medium voltage PWM ASD (adjustable speed drives) on motor stator insulation system. The findings from this study/ investigation have aided designers to improve the robustness of the insulation system used for ASD-fed motors, based on accelerated laboratory tests. (author)

  6. Alternating-Current Motor Drive for Electric Vehicles

    Krauthamer, S.; Rippel, W. E.

    1982-01-01

    New electric drive controls speed of a polyphase as motor by varying frequency of inverter output. Closed-loop current-sensing circuit automatically adjusts frequency of voltage-controlled oscillator that controls inverter frequency, to limit starting and accelerating surges. Efficient inverter and ac motor would give electric vehicles extra miles per battery charge.

  7. Modeling and Simulation of Flux-Optimized Induction Motor Drive

    Igried Dib Al-Khawaldeh

    2010-09-01

    Full Text Available The efficiency of induction motor drives under variable operating conditions can be improved by predicting the optimum flux that guarantees loss minimization. In this research, a loss-minimization scalar controller, based on determining of modulation index of IGBT inverter-based AC-to-AC converter, which corresponds to optimum flux, is proposed. For this purpose, mathematical models for total power losses as a function of magnetic flux, optimum flux as a function of operating speed and load torque, and modulation index as a function of optimum flux were analytically derived. Loss-minimized, scalar-controlled induction motor drive system was modeled, simulated and experimentally tested. The results have validated the effectiveness of this system in minimizing the motor operating losses, especially at light and medium loads. Also, the dynamic performance of the drive system has been improved. The proposed controller can be implemented in adjustable speed induction motor drive systems with variable loads, operating below rated speed.

  8. 可调式风扇传动安装座在客车上的应用%Application of an Adjustable Fan Drive Installed Stand to Bus/Coach

    叶成友

    2015-01-01

    Aiming at the abnormal wear and fracture problems of the belts with traditional fan drive equipment on a bus/coach, the author introduces a type of a solution of adjustable fan drive installation stand. This can completely solve the problem of fan drive belts abnormal wear and fracture, prolong the service life and reduce the maintenance cost.%针对目前客车上采用传统风扇传动装置存在皮带异常磨损和断裂的问题,介绍一种可调式风扇传动安装座的解决方案,彻底解决风扇传动皮带异常磨损和断裂的问题,延长使用寿命和降低维护保养成本。

  9. An Improved Internal Model Principle Based Multivariable Nonlinear Control Method with Multiclass Nonharmonic Disturbances and Its Application to Speed Control of a Motor Drive System

    Yang Yu

    2014-01-01

    Full Text Available We study the global disturbance rejection problem for a class of general multivariable nonlinear systems with multiclass nonharmonic disturbances. The paper first introduces the importance and state of the art for disturbance rejection problem and describes the control problem in the form of mathematical expressions. It stresses the multiclass disturbances produced by the exosystem satisfying certain characteristic conditions. Then, the nonlinear internal models are designed in accordance with different characteristics of multiclass external disturbances. On the basis of introduction of the control law for disturbance-free system, a multivariable state feedback controller is devised in terms of the designed internal model equations and corresponding assumptions. A Lyapunov function is constructed to theoretically prove the global uniform boundness of all signals for the multivariable closed-loop system. Finally, the presented method is applied to implement the speed control and reject the multiclass nonharmonic disturbances for a two-input motor drive system. The simulation results testify correctness and effectiveness of the presented algorithm.

  10. Traffic Offences: Planned or Habitual? Using the Theory of Planned Behaviour and habit strength to explain frequency and magnitude of speeding and driving under the influence of alcohol.

    Lheureux, Florent; Auzoult, Laurent; Charlois, Colette; Hardy-Massard, Sandrine; Minary, Jean-Pierre

    2016-02-01

    This study addresses the socio-cognitive determinants of traffic offences, in particular of speeding and drinking and driving. It has two aims: (1) to test the hypothesis of a direct effect of habits on offences (i.e., independent of intentions) by employing a specific measure of habits (i.e., the SRIH) and (2) to analyse the offences by taking account of three distinct parameters: Frequency, usual magnitude (i.e., the most frequent deviation from the law) and maximal magnitude (i.e., the greatest deviation occasionally adopted) in order to represent more accurately the variability of the offending behaviours. A total of 642 drivers replied to a questionnaire. The results corroborate the idea that intention and habit are distinct and direct determinants of offences. The use of the SRIH dismisses the criticisms made with regard to the measure of past behaviour. The distinction between the three behavioural parameters proves to be relevant, as their determinants are not exactly similar. Finally, attitude and subjective norm had direct effects on the maximal magnitude and/or on the frequency of the offence. The discussion concerns the contribution of this study to the analysis of offences as well as its limitations and addresses the theoretical plausibility of the direct effects of attitude and the subjective norm. PMID:25656057

  11. SPEED CONTROL OF DC MOTOR WITH PIC 16F877

    ÇOLAK, İlhami; Ramazan BAYINDIR

    2005-01-01

    In this study, a PI controlled separately excited direct current (DC) motor speed has been controlled using PIC 16F877 controller. In the PIC 16F877 programming as a PI controller, the speed of the motor is expected to follow the reference speed. Speed of the motor is measured by a tacho generator and then, the voltage applied to the motor is adjusted by a semiconductor power switch using pulse width modulation (PWM) technique. Drive circuit was tested with 0.9 kW DC motor. Experimental resul...

  12. Measures for speed management.

    2009-01-01

    Measures for speed management are essential for limiting the negative effects of driving too fast and at inappropriate speeds. To begin with, safe and credible speed limits need to be determined. Dynamic and variable speed limits that take into account the current circumstances, such as weather cond

  13. Improved Control of an Active-Front-End Adjustable Speed Drive with a Small dc-link Capacitor under Real Grid Conditions

    Klumpner, Christian; Liserre, Marco; Blaabjerg, Frede

    2004-01-01

    capacitors will be replaced by film capacitors in order to increase the ASD lifetime, but as this has lower energy density, the dc-link capacitance is expected to decrease. In these circumstances, operation under unbalanced and distorted supply voltage as well as high dynamic operation of the ASD makes the...... severe due to the small dc-link storage. To mitigate the latter problem it is proposed to pre-compensate the dc-link voltage reference signal considering the real grid voltage. Experiments show that the system handles successfully unbalance situation even with a small dc-link capacitor....

  14. Improvement of speed profile in induction motor drive using a new idea of PWM pulses generation base on artificial neural networks

    hojat moayedi rad; mohsen farshad; mohammad ali shamsi nejad

    2012-01-01

    Due to simplicity and low cost, induction motors are more useful than direct current motors. Hence the control of these motors is important. The pervious methods are fitted normally for a limited speed range and could not be used for high, low and very low speeds. The voltage model is suitable for high speed because the voltage drop of stator resistance is not small in low speed. The current model is suitable for low speed because of the problems of flux saturation at high speed. This researc...

  15. SPEED COMPLIANCE IN FREEWAY VARIABLE SPEED LIMIT SYSTEM – CASE STUDY OF THE PRAGUE CITY RING

    Michał MATOWICKI

    2016-03-01

    Full Text Available Many previous studies have confirmed the strong relationship between speed compliance and the frequency and severity of traffic accidents. Variable speed limit (VSL system as a measure to improve traffic safety enables the freeway system to change its posted speed limit based on various traffic and environmental conditions. Such system helps drivers to recognize the upcoming events, to adjust their driving style and in such way to address speed variation of the traffic flow. This is called speed harmonization. Although many studies researching the effect of VSL system on the traffic stream can be found, there are only few addressing its influence on the drivers behavior, particularly focusing on their tolerance limit and compliance, which has crucial meaning for future design of controlling algorithms. This study was prepared to inspect this grey area by studying the data from the VSL system at Prague city ring, describing the influence of the highway management system and its influence on drivers.

  16. Improving homogeneity by dynamic speed limit systems.

    Nes, N. van Brandenberg, S. & Twisk, D.A.M.

    2010-01-01

    Homogeneity of driving speeds is an important variable in determining road safety; more homogeneous driving speeds increase road safety. This study investigates the effect of introducing dynamic speed limit systems on homogeneity of driving speeds. A total of 46 subjects twice drove a route along 12

  17. Research of Ultrasonic Flow Meter with Driving-voltage and Gain Combined Adjustment%电压与增益联合调节的超声波流量计研制

    徐方明; 朱浩; 闫丽; 韩宇琦

    2013-01-01

    As an unimpeded measurement instrument,ultrasonic flow meters are used widely in the water supply industry,petrochemical engineering and power industry.The driving-circuits of ultrasonic transducer have an important influence on driving power and echo signal.This paper introduced the design of combined adjustment with driving-voltage of ultrasonic transducer and gain of echo signal,and provided the detailed hardware circuits and software control flow.Ultrasonic flow meters can use different driving-voltage and gain under different measure circumstances with combined adjustment of driving-voltage of ultrasonic transducer and gain of echo signal.The design enhanced driving-power of ultrasonic transducer,ensured better amplitude and SNR(signal to noise ratio) of echo signal which played important role in reducing the measuring blind area,increasing measuring distance,improving measuring accuracy and stability.%超声波流量计作为无阻碍式的流量测量仪器,被广泛应用于供水、石油、化工以及电力等工业场合,超声波换能器驱动电路直接影响着超声波发射功率和接收信号.文中首先介绍了超声波流量计换能器驱动电压和回波信号增益可联合调节的设计方案,其次描述了该方案实现的硬件电路原理及软件控制流程,最后通过试验证明通过对换能器驱动电压及回波增益的联合调节,超声波流量计可在不同工况下采用不同驱动电压和回波增益,有效增加换能器驱动功率,保证回波信号的幅值大小,提高其信噪比,对减小超声波流量计的测量盲区、增加测量距离、提高测量精度与稳定性等方面均有重要作用.

  18. Power electronic converters application in modern electrical drives for the pump stations

    The pumps are the most used working machines and they use about 20% of produced electrical energy. The pumps are typical continuous duty machines, their start up is with difficult conditions, and there are needs for the adjustable flow during their work. The modern solution for the pump drives is induction motors with soft starters or the current source inverters. Soft start with electronically change voltage is the most efficient way for the energy saving in the start up process. The classic pumps control systems is based on throttling, by pass and vanes rotation. The only way for the energy saving are adjustable speed drives, which are examined. The example shows that the investment in the adjustable speed drive will be paid back for a short time only with the lower electrical energy bills. (Author)

  19. 基于剔除机械效应的资本结构调整速度再检验%The Retest of Capital Structure′s Adjustment Speed Based on Exclusion of Mechanical Effects

    顾乃康; 邓剑兰

    2014-01-01

    The reason why research on capital structure′s adjustment speed has not yet won unanimous conclusion is that there may be a “mechanical effect” in conventional partial adjustment model .By decomposing the accounting identity of asset-liability ratio, this paper eliminates the mechanical effects caused by the change in asset size .And based on panel data of listed compa-nies in Shenzhen Stock Market and Shanghai Stock Market from 1998 to 2011 which issue A-shares only , this paper uses the two-stage estimation method to retest the adjustment speed and mean reversion of capital structure which are caused by active finan -cing behaviors of corporates .The empirical results show that:The adjustment speed of capital structure is about 13%under tra-ditional estimation which uses the change of asset-liability ratio as the dependent variable;but after excluding mechanical effects caused by changes in assets , the adjustment speed significantly drops to around 5%.The results show that , by excluding such mechanical effects , the corporate financing behaviors still induce mean reversion phenomenon of capital structure , but the speed of adjustment is so low that the trend of mean reversion is not obvious .%关于资本结构调整速度的研究至今仍未获得一致结论的原因之一在于传统的部分调整模型可能存在机械效应。通过对账面资产负债率的会计恒等式进行分解,剔除由资产规模变动引起的机械效应,在此基础上以1998年至2011年中国仅发行A股的非金融类上市公司面板数据为样本,采用两阶段估计法重新检验企业主动的融资行为对资本结构调整速度和均值反转的影响。研究结果表明,在传统的采用资产负债率变动作为因变量的估计下得到的资本结构调整速度约为13%,而剔除由资产规模变动引起的机械效应之后估计得到的调整速度明显下降到5%左右。这意味着在剔除由资产规模变动引起

  20. Improvement of speed profile in induction motor drive using a new idea of PWM pulses generation base on artificial neural networks

    hojat moayedi rad

    2012-02-01

    Full Text Available Due to simplicity and low cost, induction motors are more useful than direct current motors. Hence the control of these motors is important. The pervious methods are fitted normally for a limited speed range and could not be used for high, low and very low speeds. The voltage model is suitable for high speed because the voltage drop of stator resistance is not small in low speed. The current model is suitable for low speed because of the problems of flux saturation at high speed. This research presents a new method of PWM pulse generating in induction motors based on artificial neural networks in which, the switching pulses are generated by a multilayer feed-forward neural network that is trained by the voltage and current references. Also, for the estimation of required torque and flux information a multilayer perceptron is used. By application of this new method, there is no problem of stability at low and high speeds. The simulation results by matlab-simulink verify the proposed method in transient and steady-state operating modes.

  1. Enhanced dynamic Performance of Matrix Converter Cage Drive with Neuro-fuzzy approach

    R.R. Joshi; A.K. Wadhwani

    2007-01-01

    This paper proposes a new control algorithm for a matrix converter (MC) induction motor drive system. First, a new switching strategy, which applies a back-propagation neural network to adjust a pseudo dc bus voltage, is proposed to reduce the current harmonics of the induction motor. Next, a two-degree-of-freedom controller is proposed to improve the system performance. The controller design algorithm can be applied in an adjustable speed control system and a position control system to obtai...

  2. Optimisation of a high speed rotating composite drive shaft using a genetic algorithm - Hybrid high modulus-high resistance carbon solutions

    Montagnier, Olivier

    2011-01-01

    This study deals with the optimisation of subcritical and supercritical laminated composite drive shafts, based on a genetic algorithm. The first part focuses on the modelling of a composite drive shaft. Flexural vibrations in a simply supported composite drive shaft mounted on viscoelastic supports, including shear effects are studied. In particular, an analytic stability criterion is developed to ensure the integrity of the system. The torsional strength is then computed with the maximum stress criterion, assuming the coupling effects to be null. Torsional buckling of thin walled composite tubes is modelled using a combination between laminate theory and Fl\\"ugge theory. In the second part, the genetic algorithm is developed. The last part presents a comparative study between various composite materials solutions on a helicopter tail rotor driveline. In particular, hybrid tubes consisting of high modulus and high resistance carbon/epoxy plies are studied. These solutions make it possible to replace the conv...

  3. 气量无级调节系统的原理及应用%Principle and Application of HydroCOM Stepless Speed Adjustment System

    陈睿

    2012-01-01

    石油化工装置中的往复式压缩机常采用仪表阀旁路回流进行流量调节,造成大量能耗浪费。但在往复式压缩机上实施HydroCOM无级调节系统后,节能降耗效果十分显著。本文阐述了HydroCOM无级调节系统的节能原理、控制方案和联锁逻辑。%The bypass valve was often used to adjust the flow in reciprocating compressor in petrochemical plant, then a lot of energy were wasted. After HydroCOM system applied in reciprocating compressor, energy was saved a great deal. The principle of energy saving, the control program and the interlock logic were describled in detail.

  4. Stabilization of multi-machine power system by coordinated excitation control of multiple adjustable-speed generator/motors; Fukusu kahensoku hatsuden dendoki no reiji den`atsu kyocho seigyo ni yoru taki keito anteika

    Tatematsu, M.; Yokoyama, A. [The University of Tokyo, Tokyo (Japan)

    1996-01-20

    Since an adjustable-speed generator/motor (ASGM) is excited by AC voltage fed by a quick-response cycloconverter, a rotating speed of the rotor can be changed continuously. The ASGMs installed at some pumping-up power stations are now operated effectively for automatic frequency control under the lightly loaded condition at night by changing the pumping-up power due to the rotating speed change. It is expected, on the other hand, that under the generating condition in the daytime the ASGM will be used for enhancement of transient stability because it can generate or absorb active and reactive power independently of each other by AC excitation voltage control. This paper proposes a novel control method of excitation system of ASGM for improving the transient stability of a multi-machine power system including multiple ASGMs. The controller which is designed based on an energy function works well for the stability enhancement. In comparison with the conventional excitation control of synchronous generator and constant output control of ASGM, the effectiveness of the proposed method is shown by digital simulations. 10 refs., 5 figs., 2 tabs.

  5. Relationship between robust stability and power system damping enhancement by excitation control system of adjustable-speed generator; Kahensoku hatsudenki reiji denatsu seigyo kei ni yoru denryoku keito danpingu kojo koka to robasuto anteisei no kankei

    Shigeto, T.; Yokoyama, A. [Tokyo Univ. (Japan)

    1997-12-20

    Since Adjustable-Speed Generator (ASG) is excited by alternative voltage fed by a quick-response cycloconverter, the rotor speed can be changed continuously. The ASGs installed at sonic pumping-up power stations are now utilized for Automatic Frequency Control at night time and under the light load condition by changing the pumping-up power due to the rotating speed change. It is expected. on the other hand. that under the generating condition at day time ASG will be utilized for improvement of power system stability because it can change the active power and the reactive power independently of each other. This paper presents the effect of the excitation control system of ASG designed by robust pole allocation method which is one of the controller design techniques besed on H{infinity} control theory, on the power system damping enhancement. Eigenvalue analysis and digital time simulation are carried out for 10-machine longitudinal test power system including ASGs in order to evaluate the designed controller. 5 refs., 23 figs., 5 tabs.

  6. 四驱混合动力轿车分布式卡尔曼车速估计%Vehicle Speed Estimation Based on Distributed Kalman Filter for Four Wheel Drive Hybrid Electric Car

    赵治国; 杨杰; 吴枭威

    2015-01-01

    四驱混合动力轿车存在两轮/四轮多种驱动模式,针对某一驱动模式所设计的车速估计算法难以满足其他模式下车速估计的精度。考虑车辆不同驱动模式,利用车载传感器信号、后轮毂电机转矩信息以及既定档位下前轮转矩信息,提出两级分布式卡尔曼车速估计方法。考虑模型的强非线性,采用无味卡尔曼滤波(Unscented Kalman filter,UKF)算法设计主/子滤波器。同时为了提高UKF算法对模型误差、信号干扰的鲁棒性,实现了量测噪声均值和方差的自适应调节。基于Untire轮胎模型和滑移率递推方程,设计滑移率子滤波器;基于整车运动学模型,设计车速主滤波器;考虑不同驱动模式,利用子滤波器估计值在线融合得到车速。搭建 Carsim-Simulink 联合仿真平台,并分别在纯电动驱动模式和四轮混合驱动模式下,对车速估计算法进行仿真验证。结果表明,所提出的两级分布式卡尔曼车速估计方法能有效提高车速估计精度,并增强了对模型误差、量测信号干扰和不同驱动模式的鲁棒性。%The driving mode of hybrid electric car can be two-wheel or four-wheel drive. The speed estimation designed for a specific driving mode can hardly achieve high estimated accuracy in all modes. Focus on the changeable driving mode, a kind of distributed Kalman filter with two levels is proposed, by means of utilize vehicle sensors signals, the driving torque of rear in-wheel motors and the torque of front driving wheels at the given gear state. Considering the strongly nonlinear of the model, UKF is adopted to design the filter, and to improve the filter’s robustness on modeling error and signal noise, measurement noise mean and covariance is self-adaptive. Firstly, based on UniTire Model and recursive equation of slip rate, the sub-filter is developed; secondly, based on the vehicle Kinematics model, the master-filter can be

  7. Vehicle speed control transition module and method

    Mangan, E.L.; Conklin, B.

    1986-12-16

    An apparatus is described for automatically controlling the speed of a driverless vehicle comprising a stationary frame supporting first, second and third aligned drive tubes between tracks on the frame and which are adapted to support a driverless vehicle. A means is included for independently driving the first, second and third drive tubes such that each tube, when driven, rotates about its longitudinal axis, sensor means disposed along the frame for actuation by a driverless vehicle. The means for independently driving the drive tubes includes variable speed drive means responsive to the sensor means fro driving the second tube between first and second speeds. A method is described of automatically controlling the speed of a driverless vehicle which travels along first, second and third aligned drive tubes by frictional contact therewith. It maintains the first, second, and third drive tubes out of mechanical engagement with each other at all times, sensing the location of the driverless vehicle, driving the first drive tube at a first speed, driving the third drive tube at a second at a second speed. It also varies the speed of the second drive tube from the first speed to the second speed based on the sensed location of the driverless vehicle while the vehicle is driven by contact with the second drive tube.

  8. ADJUSTMENT FACTORS AND ADJUSTMENT STRUCTURE

    Tao Benzao

    2003-01-01

    In this paper, adjustment factors J and R put forward by professor Zhou Jiangwen are introduced and the nature of the adjustment factors and their role in evaluating adjustment structure is discussed and proved.

  9. 柴油机高速电磁阀驱动模块设计与故障诊断%Design of driving module and fault diagnosis for high-speed solenoid valve of diesel

    密刚刚; 周文华; 沈成宇; 郭修其

    2012-01-01

    According to the characteristic of driving current of the high-pressure pump and injectors' highspeed solenoid valve in the electrically controlled fuel injection system of diesel with time-pressure way, the driving circuit was designed, and the respective driving current was derived. Based on the driving circuit's characteristic, the corresponding circuit for fault detecting and diagnosing was proposed, and its veracity was proved through simulating circuit by software on the PC. The integrated fault diagnosis module was completed after the diagnosis algorithm was proposed. And the designed module was applied to an actual project. Then the experiment of actual driving and real-time fault diagnosing was operated on an electrically controlled diesel. The results showed that the pump and injector operated effectually and the parameter of the actual driving current was accurate with the system requirement. When faults occurred on the condition that the diesel worked on the middle or high speed, electronic control unit (ECU) could detect the faults and take effective actions to stop driving actuators timely. So the driving module satisfies the common rail's operating requirement. The detecting and diagnosing of open and short circuit of pump's solenoid valve and short to ground, open and inner short circuit of injector's solenoid valve is implemented. And its veracity and reliability satisfies the demand of system application.%针对时间压力式电控燃油系统的高速电磁阀——高压油泵及喷油器电磁阀的驱动电流特性,设计相应的驱动电路,得到符合要求的驱动电流.根据驱动电路特点,设计相应的故障诊断电路,并用仿真软件验证电路的准确性.在完成相应的诊断软件设计得到完整的诊断模块后,将设计的模块运用于实际工程中,在柴油机上完成了实际模块的驱动和故障诊断试验.试验结果表明:该驱动模块达到了共轨系统驱动要求,同时实现了油泵电

  10. Adjustment of the Short Track Speed Skaters'Psychology in Starting%短道速滑运动员起跑心理状态的调整

    耿丽; 刘翠佳

    2011-01-01

    比赛中短道速滑的起跑,对于整个比赛的过程和最终取得成绩起着至关重要的作用。运动员起跑时不良起跑心理状态表现为训练和比赛动机障碍、过度紧张性情绪障碍、焦虑性情绪障碍、抑制障碍,提出采取消除紧张情绪、消除焦虑和畏惧情绪、生物反馈法、集中注意力、念动训练法等方法与手段调整运动员赛前的心理状态。%The starting is crucial for a short track speed skater to perform through a competition and catch the final result. The skaters'bad psychology in starting shows the motivational perplexity of training and competition, the emotional handicap of overstrain and anxiety, the disorder of inhibitory control. The paper suggests clearing up their feelings of nervousness, anxiety and fear with the methods and means of biofeedback, focusing attention, ideomotion training.

  11. Occupational Adjustment of Immigrants

    Zorlu, Aslan

    2011-01-01

    This paper examines the speed of the occupational adjustment of immigrants using Labour Force Surveys 2004 and 2005 from Statistics Netherlands. The analysis provides new evidence that immigrants start with jobs at the lower levels of skill distribution. Their occupational achievement improves significantly with the duration of residence. The extent of this initial disadvantage and the rate of adjustment vary across immigrant groups according to the transferability of skills associated with t...

  12. High speed control of electro-mechanical transduction Advanced Drive Techniques for Optimized Step-and-Settle Response of MEMS Micromirrors

    Imboden, Matthias; Pollock, Corey; Lowell, Evan; Akbulut, Mehmet; Morrison, Jessica; Stark, Thomas; Bifano, Thomas G; Bishop, David J

    2015-01-01

    Micro/Nano Electro Mechanical Systems (MEMS/NEMS) provide the engineer with a powerful set of solutions to a wide variety of technical challenges. However, because they are mechanical systems, response times can be a limitation. In some situations, advanced engineered drive techniques can improve response times by as much as a thousand, significantly opening up the application space for MEMS/NEMS solutions.

  13. Speeding or not speeding? When subjective assessment of safe, pleasurable and risky speeds determines speeding behaviour

    Florent Lheureux

    2012-01-01

    Full Text Available It is hypothesized that in a given situation speeding behaviour is determined by three subjective speed assessments: the speed perceived as the riskiest, the speed perceived as the safest, and the speed perceived as the most pleasurable. Specifically, if these assessments are high, drivers are expected to circulate faster. Such speed perceptions are also viewed as influenced by attitudes towards speed and speed limits. 177 car drivers, included 102 men and 75 women between 18 and 72 years (M = 43, SD = 21 and with a mean driving experience of 22 years (SD = 19, answered to a questionnaire about their attitudes towards speed and speed limits, the speeds they considered as the riskiest, the safest, and the most pleasurable in three different contexts, as well as their usual speed. Data analyses (ANOVA and path analyses confirmed the influence of the three types of speed assessment on the usual speed and that the influence of attitudes on this behaviour is mediated by these three assessments. Results suggest that not only a change in attitudes and beliefs is desirable, but a concrete specification (e.g., 100 Km/h of speeds perceived as safe, pleasurable and risky is also needed in order to reduce speeding behaviour.

  14. 直流无刷高速电机驱动电路设计及改进%Design and Improvement of the High - speed Brushless DC Motor Drive Circuit

    石屾; 董春

    2011-01-01

    采用无传感器无刷直流低速电机专用调速控制芯片ML4425,设计制作了航模用直流无刷高速电机的控制器.针对目前航模用直流无刷电机速度高的特点,对用于直流无刷低速电机的传统ML4425控制系统中的相关环节进行了改进,尤其是电机的启动、驱动和保护部分.简化了航模用直流无刷高速电机的控制系统,减少了成本.%In this paper,a dedicated control chip is used to design a drive circuit of a low speed sensorless DC brushless motor.This paper has done some change of the traditional control system of ML4425,in order to adapt to the high speed of the DC brushless motor used in aircraft model, especially in parts of start, drive and protect.Simplified the control system of the DC brushless motor,so it can reduce the cost.

  15. 西山矿区煤巷掘进速度影响因素因子分析%Factor analysis on factors influencing on driving speed of coal roadway in Xishan mining area

    王玉宝; 单仁亮; 蔡炜凌; 王辉; 杨树军; 徐成

    2011-01-01

    The factor questionnaire influencing coal roadway driving in Xishan mining area was designed on the basis of site investigation and Delphi method. There are 6 first grade indexes and 28 secondary indexes which include each factors influencing driving speed of coal mine. By analysis of reliability, lanckerbaha figure is between 0. 8 and 0. 9, therefore the inside reliability of the list is acceptable. By the test of KMO and Barlett,it is suitable for factor analysis. Based on these investigation results,questionnaire outcome was carried out with SPSS 17.0 by analyzing factor,and 7 common influencing factors were abstracted about driving speed of coal area from the questionnaire. Factors include crew management, prediction skill of engineering geological conditions, equipment management, optimization of sup-porting parameter, staff quality, conditions of project rock, performance management. Aiming at the seven common fac-tors,7 specific suggestions for driving speed of coal mine were put forward.%在现场调研与专家意见法的基础上,设计了,该表共有6个一级指标和28个二级指标,基本上涵盖了影响煤巷掘进速度的各个方面.经过信度分析,克朗巴哈系数介于0.8~0.9,该量表的内在信度可以接受,经过KMO检验和Barlett球度检验,认为非常适合做因子分析.在此基础上,运用SPSS 17.0对问卷调查的结果进行因子分析,提炼出影响西山矿区煤巷掘进速度的7个公共因子:班组管理因子、工程地质条件预报水平因子、设备管理因子、支护参数优化设计因子、人员素质因子、工程岩层条件因子、绩效管理因子.针对这7个公共因子,为西山矿区煤巷快速掘进提出了7个方面的具体建议.

  16. Magnetosphere response to high-speed solar wind streams: A comparison of weak and strong driving and the importance of extended periods of fast solar wind

    Denton, Michael; Borovsky, J. E.

    2012-01-01

    Much attention has been focused on the reaction of the magnetosphere to the solar wind during the recent extended solar minimum (2006–2010). Although this period was exceptionally quiet when categorized by some parameters (e.g., the number of sunspots) the solar wind still contained features which impacted the Earth's magnetosphere and caused geomagnetic disturbances. Recurrent corotating interaction regions (CIRs) and associated high-speed solar wind streams (HSSs) are typically associated w...

  17. Research on flutter test technology of continuously adjusting dynamical pressure in high-speed wind tunnel%高速风洞连续变速压颤振试验技术研究

    郭洪涛; 闫昱; 余立; 吕彬彬; 杜宁

    2015-01-01

    针对高速暂冲式风洞阶梯变速压颤振试验用时长、耗气量大和试验模型有效使用寿命短等缺点,开展了高速暂冲式风洞连续变速压颤振试验技术研究,解决了定 Ma 数连续变速压流场控制技术与连续变速压工况下的颤振试验数据处理技术等难题。具体技术措施是:在2.4m×2.4m 暂冲式跨声速风洞中设计了基于运动函数的定Ma 数线性变总压控制策略,使 Ma 数控制精度达到了0.005以内且速压无超调,实现了流场控制目标;采用 Pick-Hold 方法构建颤振边界的亚临界预测判据,并根据预测判据近似于正态分布的特点,基于数理统计的参数估计法来减小预测判据的散布度,从而提高颤振边界亚临界预测的准确性。风洞验证试验结果表明,该试验技术达到了工程实用化水平,不仅能够取得与阶梯变速压颤振试验技术一致的结果,还能极大地节省耗气量,经济效益显著。%According to the defects shown in the flutter tests of stepped adjusting dynamical pressure in high speed intermittent wind tunnel,such as:long testing time,high gas consump-tion,and short acceptable life of testing models,researches on flutter test technology of continu-ously adjusting dynamical pressure in high-speed intermittent wind tunnels are conducted.Tech-nical problems of flutter test data processing and wind tunnel flow controlling have mainly been solved.The specific approaches are:in the 2.4m×2.4m blow off transonic wind tunnel,fixed Mach number and linear varying total pressure controlling strategies based on movement function are presented,and thus the flow controlling goal of fixed Mach number continuously adjusting dynamical pressure is achieved.The controlling uncertainty of Mach number reaches less than 0.005 without deviation of dynamical pressure.The Pick-Hold method is adopted to set up the subcritical prediction criterion in flutter boundary

  18. Research and design on synchronizing belt adjusting device of high-speed stocking machine%高速丝袜机同步带调节装置的研究与设计

    胡国军; 冯方

    2013-01-01

    根据实际生产及使用需要,要求高速丝袜机同步带的松紧能够调节。无论国内还是国外的高速丝袜机,其同步带的松紧均由机器的底座、同步带轮及同步带的制造精度所决定。而且使用一段时间后同步带有可能会松弛,严重影响机器的使用。针对这一问题,设计了一套结构简单、使用方便且可以随时调节同步带松紧的调节装置,降低了零件的生产精度,延长了同步带的使用寿命,为机器的制造商与用户提供了便利。%According to the requirement of practical production and usage ,the tightness degree for the synchronizing belt of high-speed stocking machine need adjust .Whenever the machine is manufactured at home or abroad ,the tightness of synchronizing belt is determined by the machine base ,the synchronizing belt pulley ,and the manufacturing accuracy of the belt .If the belt is used for long-time,the fatigue problem will be produced ,which could result in the serious usage .A set of creative adjusting device with the simple construct ,convenient using and timely adjusting the tightness of synchronizing belt is designed to solve the above prob -lem,which could not only decrease the production accuracy of parts ,but prolong the usage lifetime of the belt to offer the conven-ience for the machine manufacturer and custom .

  19. Compact ASD Topologies for Single-Phase Integrated Motor Drives with Sinusoidal Input Current

    Klumpner, Christian; Blaabjerg, Frede; Thoegersen, Paul

    2005-01-01

    A standard configuration of an Adjustable Speed Drive (ASD) consists of two separate units: an AC motor, which runs with fixed speed when it is supplied from a constant frequency grid voltage and a frequency converter, which is used to provide the motor with variable voltage-variable frequency...... needed to adjust the speed of the motor. The integrated motor drive concept is a result of merging the two units in order to achieve the following benefits [1-3]: reducing the design and the commissioning time in complex industrial equipments, no need for a cabinet to host the frequency converter, no...... induction motor as a boost inductor for a PFC (Power Factor Correction) stage controlled by the inverter zero-sequence voltage component. By determining how much energy is possible to store in a corner inductor, it is proven that integrating the magnetics into the stator yoke is a feasible solution...

  20. 高速直线电动机驱动进给轴热行为测试研究%Test of thermal behavior of high speed feed drive system equipped with linear motor

    林献坤; 李燕军; 吴倩倩

    2012-01-01

    This study investigated a high speed feed drive system equipped with linear motor, which was developed by ourselves. The heat distribution and thermal deformation characteristics of the closed—loop control feed drive system were analyzed qualitatively. It was shown that the thermal deformation of direct linear drives includes thermal expansion of the linear scale, pitch angle error of the guide and thermal deformation of the slide. Meanwhile, the experimental scheme and procedure, using thermocouples, laser interferometer and capacitance gage, were determined. The heat distribution and thermal deformation characteristics of direct linear drives were measured. The factors and its proportions of thermal deformation were verified through experiments on the test rig.%以自构建的直线电动机驱动高速进给轴为研究对象,对全闭环位置反馈进给轴的温度场分布和热变形特性进行了定性分析,指出直线进给轴的几何热变形可以分为光栅尺线性变形、导轨的轴向俯仰角度误差变形和滑台变形3个部分组成,探讨给出进给轴温度测量以及基于激光干涉仪、电容测微仪的变形测量原理及方案,在自构建的直线进给轴试验台上,对该热变形过程进行了综合测试研究,测试结果客观反映了导致直线进给轴热变形误差的组合要素及其所占比例.

  1. A new approach to an optimal adaptive real time DC motor drive control

    Lukic, V.P.; Hall, J.B. [North Carolina Univ., Charlotte, NC (United States)

    2007-07-01

    The dynamic operation of a DC motor drive depends on the choice of the regulator structure and synthesis of the regulator parameters. For that reason, the authors developed an approach to a real time optimal parameters adjustment for a DC motor drive. The approach is based on the system sensitivity analysis and identification theory. This innovative concept and algorithm provide a tool to control a DC motor drive in real time with an adaptive controller. The DC motor drive mathematical model was described by a set of the first order differential equations with constant coefficients. The regulator has speed and current control channels. The structure of the algorithm includes the sensitivity model, system sensitivity functions evaluation, and the circuits for the parameter incremental changes. The performance index is an integral of the squared error of the speed variation during the transients. The following four parameters were adjusted: the gains of the speed and current regulator in direct path; two gains in two feedback channels; and, speed and current control channels. The actual system was simulated by a system model and the algorithm was applied to a DC motor drive with typical parameters. Several numerical experiments were also carried out. The experiments validated the effectiveness and feasibility of the concept and algorithm. 6 refs., 5 figs., 1 appendix.

  2. Convexity Adjustments

    M. Gaspar, Raquel; Murgoci, Agatha

    2010-01-01

    A convexity adjustment (or convexity correction) in fixed income markets arises when one uses prices of standard (plain vanilla) products plus an adjustment to price nonstandard products. We explain the basic and appealing idea behind the use of convexity adjustments and focus on the situations o...

  3. High Speed Flexible Optical Disk with Cylindrically Concaved Stabilizer

    Aman, Yasutomo; Onagi, Nobuaki; Murata, Shozo; Sugimoto, Yasunori; Koide, Daiichi; Tokumaru, Haruki

    2007-06-01

    We developed a brand-new stabilizer with a cylindrically concaved active surface for a flexible optical disk system. The unique design enabled extremely stable driving of the flexible disk at rotational speeds over 10,000 rpm. We actually demonstrated the driving at rotational speeds of up to 15,000 rpm, the spindle motor limit of our optical disk tester. This highest rotational speed promises a maximum data transfer rate of more than 600 Mbps for the recording density of a Blu-ray Disc. This stable state was achieved using a simple control that just adjusts the relative axial position of the stabilizer against the flexible disk. Once the adjustment was made, high stability was maintained over a wide rotational speed, ranging from 4,000 to 15,000 rpm. In this stable state, the axial runout on the pickup scanning line was suppressed to less than 10 μm at all rotational speeds. By achieving this high performance with simplified stabilizer control, we have come close to putting our system into practical use.

  4. Analysis of Control Characteristic for the Drive System of Electric Transit Bus

    张承宁; 李红林; 孙逢春; 张旺

    2003-01-01

    The drive control system of the permanent magnetic direct current motor with the enhanced magnetism windings used in the electric transit bus is developed. The mathematics model of the drive control system for this motor is established. The new mode that the added-exiting magnetism field could be weakened and the speed of the motor could be controlled automatically is proposed and realized. The method of root locus design is applied to analyze the acceleration control characteristic. The results of simulation show that the new drive motor control system has extraordinary response characteristic and adjustable performance. Experiments of vehicle running show that the drive control system's antijamming ability is strong and the adjustable performance is fast and smooth, it can meet the demand of power characteristic very well.

  5. Experimental Evaluation of Turning Vane Designs for High-speed and Coupled Fan-drive Corners of 0.1-scale Model of NASA Lewis Research Center's Proposed Altitude Wind Tunnel

    Gelder, Thomas F.; Moore, Royce D.; Shyne, Rickey J.; Boldman, Donald R.

    1987-01-01

    Two turning vane designs were experimentally evaluated for the fan-drive corner (corner 2) coupled to an upstream diffuser and the high-speed corner (corner 1) of the 0.1 scale model of NASA Lewis Research Center's proposed Altitude Wind Tunnel. For corner 2 both a controlled-diffusion vane design (vane A4) and a circular-arc vane design (vane B) were studied. The corner 2 total pressure loss coefficient was about 0.12 with either vane design. This was about 25 percent less loss than when corner 2 was tested alone. Although the vane A4 design has the advantage of 20 percent fewer vanes than the vane B design, its vane shape is more complex. The effects of simulated inlet flow distortion on the overall losses for corner 1 or 2 were small.

  6. 调速控制技术在静压传动叉车中的应用%Application of Speed Regulation Technology to Hydrostatic Drive Type Forklift

    张战团

    2012-01-01

    In order to upgrade work efficiency of the hydrostatic-driven forklift truck a method was taken to regulate RPM of the hydraulic motor by readjusting the motor's capacity so that the forklift truck can change its speed according to loaded or unloaded work conditions. 2 types of fork-lift truck were taken for instance, one type is for loading and unloading containers, and the other one is an off-highway type, which was followed by introduction of the 2 types' hydrostatic power regulation.%为提高静压传动叉车的工作效率,采用改变液压马达容积进行调速的方法,使叉车的行走速度能够根据空载和满载的作业工况进行变化.以箱内作业车和越野型叉车为例,分别介绍两种静压传动叉车的调速方法.

  7. Sensitivity of hydrologic simulations to bias corrected driving parameters

    Papadimitriou, Lamprini; Grillakis, Manolis; Koutroulis, Aristeidis; Tsanis, Ioannis

    2016-04-01

    Climate model outputs feature systematic errors and biases that render them unsuitable for direct use by the impact models. To deal with this issue many bias correction techniques have been developed to adjust the modelled variables against observations. For the most common applications adjustment concerns only precipitation and temperature whilst for others all the driving parameters (including radiation, wind speed, humidity, air pressure) are bias adjusted. Bias adjusting only part of the variables required as biophysical model input could affect the physical consistency among input variables and is poorly studied. It is important to determine and quantify the effect that bias adjusting each climate variable has on the impact model's simulation and identify parameters that could be treated as raw outputs for specific model applications. In this work, the sensitivity of climate simulations to bias adjusted driving parameters is tested by conducting a series of model runs, for which the impact model JULES is forced with: i) not bias corrected input variables, ii) all bias corrected input variables, iii-viii) all input variables bias corrected except for: iii) precipitation, iv) temperature, v) radiation, vi) specific humidity, vii) air pressure and viii) wind speed. This set of runs is conducted for three climate models of different equilibrium climate sensitivity: GFDL-ESM2M, MIROC-ESM-CHEM and IPSL-CM5A-LR. The baseline for the comparison of the experimental runs is a JULES run forced with the WFDEI dataset, the dataset that was used as the observational dataset for adjusting biases. The comparative analysis is performed using the time period 1981-2010 and focusing on output variables of the hydrological cycle (runoff, evapotranspiration, soil moisture).

  8. Development of a Test Machine for IVECO Drive Axle

    WANG Liang-mo; WANG He-fu; CHEN Jin-rong; LING Zhi-liang; CAO Yu-hua

    2007-01-01

    To improve the automation level of the vehicle drive axle test and better simulate a vehicle′s actual operation, an advanced test machine has been developed. The load system of the machine consists of hand brakes and electric cylinders. It is simple-structured and low-cost. The major motor of the machine is controlled by a transducer and its speed can be adjusted easily. In addition, the programmed machine can automatically test such parameters as the grinding condition, the differential speed, the noise level, etc. It can also adjust the test procedures according to different requirements. Detailed discussion of the structure and mechanism of the test machine is given in this paper.

  9. Cycloconverter drive systems. Cycloconverter gijutsu

    Chiashi, M.; Osawa, H.; Endo, K. (Fuji Electric Co. Ltd., Tokyo (Japan))

    1991-10-10

    Fuji Electric has completed preparation for the production of various cycloconverter variable-speed AC drive systems used for low-speed large-capacity drives, and is ready to supply the optimum system to meet purposes. Among cycloconverter drive systems of Fuji Electric, circulating current-free cycloconverter fed synchronous motor drive is superior in respect of input power factor and equipment capacity, induction motor drive is superior in respect of maintenance, and circulating current cycloconverter fed motor drive is superior in respect of controllability. This report describes outlines, system components, comparison of performances, control systems and their characteristics, and technology for advanced performance of these various cycloconverter drive systems. Furthermore, was introduced a development of hybrid cycloconverter using a GTO thyristor which can regulate input power factor at 1. 2 refs., 14 figs., 1 tab.

  10. Demonstration of variable speed permanent magnet generator at small, low-head hydro site

    Brown Kinloch, David [Shaker Landing Hydro Associates, Inc., Louisville, KY (United States)

    2015-12-18

    Small hydro developers face a limited set of bad choices when choosing a generator for a small low-head hydro site. Direct drive synchronous generators are expensive and technically complex to install. Simpler induction generators are higher speed, requiring a speed increaser, which results in inefficiencies and maintenance problems. In addition, both induction and synchronous generators turn at a fixed speed, causing the turbine to run off its peak efficiency curve whenever the available head is different than the designed optimum head.The solution to these problems is the variable speed Permanent Magnet Generators (PMG). At the Weisenberger Mill in Midway, KY, a variable speed Permanent Magnet Generator has been installed and demonstrated. This new PMG system replaced an existing induction generator that had a HTD belt drive speed increaser system. Data was taken from the old generator before it was removed and compared to data collected after the PMG system was installed. The new variable speed PMG system is calculated to produce over 96% more energy than the old induction generator system during an average year. This significant increase was primarily due to the PMG generator operating at the correct speed at the maximum head, and the ability for the PMG generator to reduce its speed to lower optimum speeds as the stream flow increased and the net head decreased.This demonstration showed the importance of being able to adjust the speed of fixed blade turbines. All fixed blade turbines with varying net heads could achieve higher efficiencies if the speed can be matched to the optimum speed as the head changes. In addition, this demonstration showed that there are many potential efficiencies that could be realized with variable speed technology at hydro sites where mismatched turbine and generator speeds result in lower power output, even at maximum head. Funding for this project came from the US Dept. of Energy, through Award Number DE-EE0005429.

  11. Adjustment disorder

    American Psychiatric Association. Diagnostic and statistical manual of mental disorders . 5th ed. Arlington, VA: American Psychiatric Publishing. 2013. Powell AD. Grief, bereavement, and adjustment disorders. In: Stern TA, Fava ...

  12. Adjustment disorder

    American Psychiatric Association. Diagnostic and statistical manual of mental disorders. 5th ed. Arlington, Va: American Psychiatric Publishing. 2013. Powell AD. Grief, bereavement, and adjustment disorders. In: Stern TA, Rosenbaum ...

  13. Deliberately dispatched SCR firing angles for harmonic mitigation in three-phase multi-drive systems without communication

    Yang, Yongheng; Davari, Pooya; Zare, Firuz;

    2016-01-01

    Adjustable Speed Drives (ASDs) are widely used in threephase multi-drive applications in industry, where low-cost Diode Rectifiers (DRs) or Silicon-Controlled Rectifiers (SCRs) are still employed as the front-ends in practice, also for simplicity. However, the associated harmonics are produced...... witnessed in industry. In this sense, this paper proposes a harmonic mitigation strategy for multiple parallel ASD systems, where the firing angles of the SCR units are deliberately dispatched among the SCR drive units, resulting in certain phase shifts of the SCR currents on purpose. In such a manner...

  14. Gaze-controlled Driving

    Tall, Martin; Alapetite, Alexandre; San Agustin, Javier;

    2009-01-01

    We investigate if the gaze (point of regard) can control a remote vehicle driving on a racing track. Five different input devices (on-screen buttons, mouse-pointing low-cost webcam eye tracker and two commercial eye tracking systems) provide heading and speed control on the scene view transmitted...

  15. Optimization design of wind turbine drive train based on Matlab genetic algorithm toolbox

    Li, R. N.; Liu, X.; Liu, S. J.

    2013-12-01

    In order to ensure the high efficiency of the whole flexible drive train of the front-end speed adjusting wind turbine, the working principle of the main part of the drive train is analyzed. As critical parameters, rotating speed ratios of three planetary gear trains are selected as the research subject. The mathematical model of the torque converter speed ratio is established based on these three critical variable quantity, and the effect of key parameters on the efficiency of hydraulic mechanical transmission is analyzed. Based on the torque balance and the energy balance, refer to hydraulic mechanical transmission characteristics, the transmission efficiency expression of the whole drive train is established. The fitness function and constraint functions are established respectively based on the drive train transmission efficiency and the torque converter rotating speed ratio range. And the optimization calculation is carried out by using MATLAB genetic algorithm toolbox. The optimization method and results provide an optimization program for exact match of wind turbine rotor, gearbox, hydraulic mechanical transmission, hydraulic torque converter and synchronous generator, ensure that the drive train work with a high efficiency, and give a reference for the selection of the torque converter and hydraulic mechanical transmission.

  16. Optimization design of wind turbine drive train based on Matlab genetic algorithm toolbox

    In order to ensure the high efficiency of the whole flexible drive train of the front-end speed adjusting wind turbine, the working principle of the main part of the drive train is analyzed. As critical parameters, rotating speed ratios of three planetary gear trains are selected as the research subject. The mathematical model of the torque converter speed ratio is established based on these three critical variable quantity, and the effect of key parameters on the efficiency of hydraulic mechanical transmission is analyzed. Based on the torque balance and the energy balance, refer to hydraulic mechanical transmission characteristics, the transmission efficiency expression of the whole drive train is established. The fitness function and constraint functions are established respectively based on the drive train transmission efficiency and the torque converter rotating speed ratio range. And the optimization calculation is carried out by using MATLAB genetic algorithm toolbox. The optimization method and results provide an optimization program for exact match of wind turbine rotor, gearbox, hydraulic mechanical transmission, hydraulic torque converter and synchronous generator, ensure that the drive train work with a high efficiency, and give a reference for the selection of the torque converter and hydraulic mechanical transmission

  17. Energy optimized sliding-mode control of sensorless induction motor drives

    In this paper a sensorless sliding-mode (SM) direct torque and flux control is described for three-phase induction motor (IM) drive. The IM drive is supplied with a two level space vector modulation (SVM) voltage source inverter. A conventional PI speed controller is employed to generate the desired torque command in the case of speed control. Stator and rotor flux vectors are estimated using a sliding-mode observer and are employed in rotor speed estimation. Moreover, the IM model includes the iron losses through a speed dependent shunt resistance in the motor two axis equivalent circuits. Motor efficiency is also optimized by adjusting the magnitude of the stator flux reference for each value of motor load and speed. For this purpose, an on-line search method (OSM) is adopted. According to this method, for each given value of load torque and rotor speed, the stator flux reference is adjusted so that the average of real input power becomes minimized. Simulation and experimental results are presented to show the capability and validity of the proposed control scheme.

  18. Driving Resistance from Railroad Trains

    Lindgreen, Erik Bjørn Grønning; Sorenson, Spencer C

    2005-01-01

    This report methods and parameters for calculating the driving resistance of railroad trains. Calculations and comparisons are presented for aerodynamic, rolling and total resistance for a variety of freight trains under different loading conditions, operating speed and configuration. Simplified...... methods are presented for the estimation of the driving resistance for passenger trains. This report is a supplement to the ARTEMIS rail emissions model....

  19. Influence of roadside infrastructure on driving behavior: driving simulator study

    Horst, A.R.A. van der; Ridder, S. de

    2007-01-01

    This paper describes the results of a driving simulator study that focused on the influence of roadside infrastructure on speed choice and lateral placement of car drivers. A review of the RISER detailed accident database revealed that lateral positioning and speed of the vehicle were two of the pri

  20. Quantum effects in warp drives

    Finazzi Stefano

    2013-01-01

    Warp drives are interesting configurations that, at least theoretically, provide a way to travel at superluminal speed. Unfortunately, several issues seem to forbid their realization. First, a huge amount of exotic matter is required to build them. Second, the presence of quantum fields propagating in superluminal warp-drive geometries makes them semiclassically unstable. Indeed, a Hawking-like high-temperature flux of particles is generated inside the warp-drive bubble, which causes an expon...

  1. Reduction in iron losses in Indirect Vector-Controlled IM Drive using FLC

    Srisailam, C; Trivedi, Anurag

    2010-01-01

    This paper describes the use of fuzzy logic controller for efficiency optimization control of a drive while keeping good dynamic response. At steady-state light-load condition, the fuzzy controller adaptively adjusts the excitation current with respect to the torque current to give the minimum total copper and iron loss. The measured input power such that, for a given load torque and speed, the drive settles down to the minimum input power, i.e., operates at maximum efficiency. The low-frequency pulsating torque due to decrementation of flux is compensated in a feed forward manner. If the load torque or speed commands changes, the efficiency search algorithm is abandoned and the rated flux is established to get the best dynamic response. The drive system with the proposed efficiency optimization controller has been simulated with lossy models of converter and machine, and its performance has been thoroughly investigated.

  2. Regulating vacuum pump speed with feedback control

    Considerable energy is wasted by the vacuum pump/motor on dairy farms. The output capacity (m3/min or cfm) of the vacuum pump always exceeds the capacity needed to milk cows and wash pipelines. Vacuum pumps run at full speed and load regardless of actual need for air. Excess air is admitted through a controller. Energy can be saved from electrical demand reduced by regulating vacuum pump speed according to air based on air usage. An adjustable speed drive (ASD) on the motor and controlled based upon air usage, can reduce the energy used by the vacuum pump. However, the ASD unit tested could not maintain vacuum levels within generally accepted guidelines when air usage changed. Adding a high vacuum reserve and a dual vacuum controller between the vacuum pump and the milking pipeline brought vacuum stability within guidelines. The ASD/dual vacuum system can reduce energy consumption and demand by at least 50 percent during milking and provide better vacuum stability than conventional systems. Tests were not run during washing cycles. Using 1990 costs and only the energy saved during milking, the simple payback on investment in new equipment for a 5 hp motor, speed controller and vacuum regulator would be about 5 years

  3. Speed Control of a Three Phase Alternating Current Induction Motor Using Space Vector Pulse Width Modulation

    Angelo A. Beltran Jr.

    2014-01-01

    Sinusoidal pulse width modulation is a popular modulation for most alternating current induction motor. It only requires fewer calculations and is easy to implement. However, the shortcomings of using it are low DC voltage utilization, and poor inverter transmission capability. In recent years, there is an increasing trend and more research concentration of using space vector pulse width modulation in adjustable speed drives and renewable energy systems because...

  4. Active damping technique for small DC-link capacitor based drive system

    Maheshwari, Ram Krishan; Munk-Nielsen, Stig; Henriksen, Bjarne;

    2010-01-01

    A detailed model of Adjustable Speed Drive (ASD) is discussed, which yield a general rule for active damping in a small DC link based drive. A desired value of input LC resonance damping coefficient can be achieved by changing gain parameters. The modified state space matrix due to active damping...... terms is also presented. The performance of the active damping is evaluated based on experimental results. A simple model is presented which can be used to measure the damping factor provided by the system parameters only....

  5. Enhanced dynamic Performance of Matrix Converter Cage Drive with Neuro-fuzzy approach

    R.R. Joshi

    2007-06-01

    Full Text Available This paper proposes a new control algorithm for a matrix converter (MC induction motor drive system. First, a new switching strategy, which applies a back-propagation neural network to adjust a pseudo dc bus voltage, is proposed to reduce the current harmonics of the induction motor. Next, a two-degree-of-freedom controller is proposed to improve the system performance. The controller design algorithm can be applied in an adjustable speed control system and a position control system to obtain good transient responses and good load disturbance rejection abilities. The implementation of this kind of controller is only possible by using a high-speed digital signal processor. In this paper, all the control loops, including current-loop, speed-loop, and position-loop, are implemented by TMS320C6711 digital signal processor. Several experimental results are shown to validate the theoretical analysis.

  6. Electric drives

    Boldea, Ion

    2005-01-01

    ENERGY CONVERSION IN ELECTRIC DRIVESElectric Drives: A DefinitionApplication Range of Electric DrivesEnergy Savings Pay Off RapidlyGlobal Energy Savings Through PEC DrivesMotor/Mechanical Load MatchMotion/Time Profile MatchLoad Dynamics and StabilityMultiquadrant OperationPerformance IndexesProblemsELECTRIC MOTORS FOR DRIVESElectric Drives: A Typical ConfigurationElectric Motors for DrivesDC Brush MotorsConventional AC MotorsPower Electronic Converter Dependent MotorsEnergy Conversion in Electric Motors/GeneratorsPOWER ELECTRONIC CONVERTERS (PECs) FOR DRIVESPower Electronic Switches (PESs)The

  7. Efficient Disengaging Hooks System Based on Constant-Power Speed Regulation of Frequency Converter

    Jianjian Wang

    2013-04-01

    Full Text Available In the traditional port, disengaging hook system adopts a three-phase power frequency power to drive a three-phase asynchronous motor. The operation is simple and the maintenance is convenient. However, it still keeps the speed of mooring lines constant. Under the light-load condition, the work efficiency could be affected because of the low speed. To solve this problem, we start the research in speed control of disengaging hook. By using variable frequency control technology to transform the original system and using frequency converter to carry on the constant-power speed regulation, technicians also adopt vector control algorithm with PG to achieve adjustable speed of cable volume. The motor is under no load or light load state with high-speed after starting and turns into low-speed through full load. It makes motor stay in constant-power state when it works. This design solves the low-efficiency of disengaging hook in the past and makes system achieve adjustable motor speed. In this design and application, not only can technicians reduce the initial cost, but also they can reduce operating costs markedly by adopting energy-saving control equipment at the same time.

  8. 宽范围调速电动汽车用IPM电机驱动控制算法%Driving control of IPM motors with wide-range speed-regulation for electrical vehicles

    贾要勤; 龙飞; 曹慧敏

    2012-01-01

    Interior permanent magnet (IPM) synchronous motors are widely used in electric vehicles. This paper investigates the driving control of IPM motors with Hall position sensors to realize large torque starting, wide range of speed regulation and high efficiency operation. The driving control strategy combines the improved Hall prediction algorithms with the first-order Hall position algorithms. Simulation and experimental results show that the maximum error of rotor position detection is less than 0.3 rad using the proposed strategy when the motor starts. The proposed flux weakening method has a better robustness compared with the traditional flux-weakening control. The motor efficiency is increased by 1% compared with that of the zero quadrature axis current control, when using table look-up control strategy and average-voltage dead-time compensation method.%凸极式永磁(IPM)同步电机被广泛用于电动汽车驱动系统。为实现IPM电机的大转矩启动、宽范围调速和高效率运行,该文研究了用于电动汽车的带有Hall位置传感器的IPM电机驱动控制策略。该控制策略联合了改进的Hall预估算法与一阶Hall位置算法结合的方法。仿真和实验研究表明:在电机启动时,估算出的转子位置与实际转子位置最大误差减小到0.3rad。与普通弱磁扩速控制方法相比,采用改进的弱磁扩速控制方法,增强了控制算法的鲁棒性。采用离线制表一查表的运行控制策略和平均误差电压死区补偿方法后,与交轴电流为零的控制算法相比较,电机效率提高了1%。

  9. Permanent magnet brushless drives

    Chan, CC; Xia, W.; Jiang, JZ; Chau, KT; Zhu, ML

    1998-01-01

    The purpose of this paper is to present an optimal efficiency control scheme for constant power operation of phase decoupling (PD) PM brushless DC motor drives. The key is to adaptively adjust the advanced conduction angle to minimize the system losses for a given operation point in the constant power region. The strategy for constant power operation of PD PM brushless DC motor drives is exemplified using a 5-phase 22-pole PD PM brushless DC motor. In the sections that follow, the newly-devel...

  10. Library of Samples for E-Vehicle Propulsion Drive Tuning

    Rassõlkin Anton

    2014-05-01

    Full Text Available The majority of testing cycles for the vehicle comparison is the long-term cycles and could not be used for the short-term transient mode imitations. Also, all the used nowadays testing cycles were designed for internal combustion engine vehicles and take into account not only energy and mechanical aspects, but also pollution and internal combustion engine characteristics. The paper presents a collection of sample signals developed to explore and simulate multiple system impacts to emulate different reference and load conditions. The study describes the major driving modes, such as the constant-speed cruising, speeding up and braking, typical parking regimes, uphill and downhill motion, and taking a turn. The developed testing equipment and software are described. Responses of the battery vehicle drives to the changeable controls and disturbances were studied in the laboratory test bench. The set of test cycles prepared in the frame of the ABB control arrangement was applied to the system evaluation and assessment. The developed methodology can be recommended to adjust the electric drives for different kinds of testing equipment. Experimental validation of the described approach has demonstrated the broad possibilities for the steady-state and transient modes of vehicle quality evaluation. It suits for recommendations that can be made with regard to the tuning of the drive regulators, control looping, sensor allocation, and feedback arrangements.

  11. When is speed a problem?.

    Wesemann, P.

    1986-01-01

    It is relatively useless to make pronouncements on what, in certain circumstances, is a safe driving speed for road users; it is interesting, however, to indicate what is an optimum speed from the social point of view, after weighing up the various pros and cons, including safety. Ultimately this is

  12. Salary adjustments

    HR Department

    2008-01-01

    In accordance with decisions taken by the Finance Committee and Council in December 2007, salaries are adjusted with effect from 1 January 2008. Scale of basic salaries and scale of stipends paid to fellows (Annex R A 5 and R A 6 respectively): increased by 0.71% with effect from 1 January 2008. As a result of the stability of the Geneva consumer price index, the following elements do not increase: a)\tFamily Allowance, Child Allowance and Infant Allowance (Annex R A 3); b)\tReimbursement of education fees: maximum amounts of reimbursement (Annex R A 4.01) for the academic year 2007/2008. Related adjustments will be applied, wherever applicable, to Paid Associates and Students. As in the past, the actual percentage increase of each salary position may vary, due to the application of a constant step value and rounding effects. Human Resources Department Tel. 73566

  13. Salary adjustments

    HR Department

    2008-01-01

    In accordance with decisions taken by the Finance Committee and Council in December 2007, salaries are adjusted with effect from 1 January 2008. Scale of basic salaries and scale of stipends paid to fellows (Annex R A 5 and R A 6 respectively): increased by 0.71% with effect from 1 January 2008. As a result of the stability of the Geneva consumer price index, following elements do not increase: a) Family Allowance, Child Allowance and Infant Allowance (Annex R A 3). b) Reimbursement of education fees: maximum amounts of reimbursement (Annex R A 4.01) for the academic year 2007/2008. Related adjustments will be implemented, wherever applicable, to Paid Associates and Students. As in the past, the actual percentage increase of each salary position may vary, due to the application of a constant step value and the rounding effects. Human Resources Department Tel. 73566

  14. Speeding Up

    YU SHUJUN

    2010-01-01

    In the wake of the global financial crisis, China has amazed the world with the speed of its economic recovery. But what has been even more surprising is the speed of its railway evolution. The unveiling of the 1,069-km Wuhan-Guangzhou High-speed Railway on December 26, 2009 pushed China's high-speed rail sys-tem-the total mileage, the average speed and the technology-to rank first in the world almost overnight.

  15. Adjustable collimator

    In a rotating fan beam tomographic scanner there is included an adjustable collimator and shutter assembly. The assembly includes a fan angle collimation cylinder having a plurality of different length slots through which the beam may pass for adjusting the fan angle of the beam. It also includes a beam thickness cylinder having a plurality of slots of different widths for adjusting the thickness of the beam. Further, some of the slots have filter materials mounted therein so that the operator may select from a plurality of filters. Also disclosed is a servo motor system which allows the operator to select the desired fan angle, beam thickness and filter from a remote location. An additional feature is a failsafe shutter assembly which includes a spring biased shutter cylinder mounted in the collimation cylinders. The servo motor control circuit checks several system conditions before the shutter is rendered openable. Further, the circuit cuts off the radiation if the shutter fails to open or close properly. A still further feature is a reference radiation intensity monitor which includes a tuning-fork shaped light conducting element having a scintillation crystal mounted on each tine. The monitor is placed adjacent the collimator between it and the source with the pair of crystals to either side of the fan beam

  16. Offset Compound Gear Drive

    Stevens, Mark A.; Handschuh, Robert F.; Lewicki, David G.

    2010-01-01

    The Offset Compound Gear Drive is an in-line, discrete, two-speed device utilizing a special offset compound gear that has both an internal tooth configuration on the input end and external tooth configuration on the output end, thus allowing it to mesh in series, simultaneously, with both a smaller external tooth input gear and a larger internal tooth output gear. This unique geometry and offset axis permits the compound gear to mesh with the smaller diameter input gear and the larger diameter output gear, both of which are on the same central, or primary, centerline. This configuration results in a compact in-line reduction gear set consisting of fewer gears and bearings than a conventional planetary gear train. Switching between the two output ratios is accomplished through a main control clutch and sprag. Power flow to the above is transmitted through concentric power paths. Low-speed operation is accomplished in two meshes. For the purpose of illustrating the low-speed output operation, the following example pitch diameters are given. A 5.0 pitch diameter (PD) input gear to 7.50 PD (internal tooth) intermediate gear (0.667 reduction mesh), and a 7.50 PD (external tooth) intermediate gear to a 10.00 PD output gear (0.750 reduction mesh). Note that it is not required that the intermediate gears on the offset axis be of the same diameter. For this example, the resultant low-speed ratio is 2:1 (output speed = 0.500; product of stage one 0.667 reduction and stage two 0.750 stage reduction). The design is not restricted to the example pitch diameters, or output ratio. From the output gear, power is transmitted through a hollow drive shaft, which, in turn, drives a sprag during which time the main clutch is disengaged.

  17. Impaired Driving

    ... help prevent injuries and deaths from alcohol-impaired driving. The Problem Risk Factors BAC Effects Prevention Additional Resources How big is the problem? In 2014, 9,967 people were killed in alcohol-impaired driving crashes, accounting for nearly one-third (31%) of ...

  18. Distracted Driving

    ... 18%) in which someone was injured involved distracted driving. 1 What are the risk factors? Activities Some activities—such as texting—take the driver’s attention away from driving more frequently and for longer periods than other ...

  19. Research of Double Internal Model Control for Cycloconverter-fed Adjustable Speed Drive System of Induction Motor%感应电动机交-交变频调速系统的双内模控制研究

    周渊深

    2005-01-01

    基于先进的内模控制理论,提出了一种双内模控制结构,将内模控制拓展应用到多环控制的感应电动机交-交变频调速系统的外环;仿照调速系统调节器的工程设计方法,提出了基于内模控制原理的调速系统调节器设计原则,并进行了调节器设计.所设计的电流调节器为PI结构、磁链和转速调节器为PI或PID结构,但都只有一个可调参数,结构简单,参数调整方便.仿真实验表明,采用内模控制后,系统的输出动态性能优于工程设计方法设计的动态性能.

  20. Study and Analysis of Three Phase Voltage Source Inverter Fed Induction Motor Drive in Various Pulse Width Modulation Techniques

    S. Manivannan, S. Veerakuma; P. Karuppusamy, A. Nandhakumar

    2014-01-01

    The Three Phase Voltage Source Inverter supplies invariably required variable voltage and frequency of the adjustable speed drive system. A number of pulse width modulation (PWM) schemes are used to obtain variable voltage and frequency supply from an inverter. The most widely used PWM scheme for a Three Phase Voltage Source Inverter is carrier based sinusoidal PWM and Space Vector Pulse Width Modulation (SVPWM). There is an increasing trend of using SVPWM, beca...

  1. Comparison Between Line Start PM Synchronous Motor and Induction Motor With Same Nominal Power and Same Pole Pairs When Fed By VF Control Drive

    Ali Reza Sadoughi

    2015-03-01

    Full Text Available Given the importance of electric machines in the industry with high efficiency, and speed control of this machines are also important, in this paper, three-phase line start permanent magnet synchronous motor and three-phase induction motors that are same in nominal power and the number of poles, is controled, monitored and compared by open-loop voltage to frequency drive, with each other. To this end, simulating the same conditions for the launch of electronic drive with open loop control V/Hz with constant load torque is provided.Simulation results from MATLAB/Simulink software are presented for both line-starting and Adjustable Speed Drive (ASD applications in the same situations, to provide a comprehensive comparison, and it shows a transient and steady-state response of an LSPMSM drive compared to its IM.

  2. Driving offences

    Corbett, C

    2010-01-01

    Copyright @ 2010, Taylor & Francis Group. This material is posted on this site with the permission of the publishers. This chapter on driving offences will largely follow the template of earlier chapters except that owing to their vast number, a limited selection only will be examined based on their high volume, seriousness and public concern. The first section will define what driving offences are, how they developed alongside the emerging car culture, and it will consider the contempora...

  3. Direct Torque Control of Sensorless Induction Motor Drives: A Sliding-Mode Approach

    Lascu, Cristian; Boldea, Ion; Blaabjerg, Frede

    2004-01-01

    Direct torque control (DTC) is known to produce fast response and robust control in ac adjustable-speed drives. However, in the steady-state operation, notable torque, flux, and current pulsations occur. A new, direct torque and flux control strategy based on variable-structure control and space......-vector pulsewidth modulation is proposed for induction motor sensorless drives. The DTC transient merits and robustness are preserved and the steady-state behaviour is improved by reducing the torque and flux pulsations. A sliding-mode observer using a dual reference frame motor model is introduced and tested....... Simulations and comparative experimental results with the proposed control scheme, versus classic DTC, are presented. Very-low-speed sensorless operation (3 r/min) is demonstrated....

  4. An Improved Power Quality Based Sheppard-Taylor Converter Fed BLDC Motor Drive

    Singh, Bhim; Bist, Vashist

    2015-12-01

    This paper deals with the design and analysis of a power factor correction based Sheppard-Taylor converter fed brushless dc motor (BLDCM) drive. The speed of the BLDCM is controlled by adjusting the dc link voltage of the voltage source inverter (VSI) feeding BLDCM. Moreover, a low frequency switching of the VSI is used for electronically commutating the BLDCM for reduced switching losses. The Sheppard-Taylor converter is designed to operate in continuous conduction mode to achieve an improved power quality at the ac mains for a wide range of speed control and supply voltage variation. The BLDCM drive is designed and its performance is simulated in a MATLAB/Simulink environment to achieve the power quality indices within the limits of the international power quality standard IEC-61000-3-2.

  5. Semiclassical instability of warp drives

    Warp drives, at least theoretically, provide a way to travel at superluminal speeds. However, even if one succeeded in providing the necessary exotic matter to construct them, it would still be necessary to check whether they would survive to the switching on of quantum effects. In this contribution we will report on the behaviour of the Renormalized Stress-Energy Tensor (RSET) in the spacetimes associated with superluminal warp drives. We find that the RSET will exponentially grow in time close to the front wall of the superluminal bubble, hence strongly supporting the conclusion that the warp-drive geometries are unstable against semiclassical back-reaction.

  6. A Multi-Pulse Pattern Modulation Scheme for Harmonic Mitigation in Three-Phase Multi-Motor Drives

    Davari, Pooya; Yang, Yongheng; Zare, Firuz; Blaabjerg, Frede

    2016-01-01

    Continuous improvement of power electronics technology has widely increased the applications of adjustable speed motor drives in many areas. Beyond the control flexibility, the power electronics devices (e.g., diode rectifiers) are also the main harmonic source to the grid due to their nonlinearity......, which thus deteriorates the power grid quality and also lowers the conversion efficiency. Both degradations are apt to occur in motor drive applications. At present, many industrial drives are equipped with three-phase diode rectifiers and employ passive filtering techniques on the AC or DC side of the...... rectifier. In such topologies, it is difficult to implement the prior-art harmonic control strategies. Moreover, the total cost and complexity has become the main obstacle for these harmonic elimination approaches in multiple drive systems. Therefore, in this paper, a new cost-effective harmonic mitigation...

  7. Maximum torque per ampere control of sensorless induction motor drives with dc offset and parameter compensation

    Markadeh, Gholamreza Arab [Faculty of Engineering, Shahrekord University, Shahrekord (Iran, Islamic Republic of); Hajian, Masood, E-mail: m.hajian@ec.iut.ac.i [Department of Electrical and Computer Engineering, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of); Soltani, Jafar; Hosseinia, Saeed [Department of Electrical and Computer Engineering, Isfahan University of Technology, Isfahan (Iran, Islamic Republic of)

    2010-07-15

    Field orientation control of induction machine (IM) drives is a well-known strategy which has a fast dynamic response. In this paper, the direct rotor flux field orientation control of speed sensorless IM drive is presented. A two level space vector modulation inverter is employed to generate the command stator voltage. In proposed control scheme, a maximum torque per ampere strategy is achieved using a so-called fast flux search method. Based on this method, for a given load torque and rotor speed, the magnitude of rotor reference flux is adjusted step by step until the effective value of stator current becomes minimized finally. In addition, using the IM fifth order model in the stationary reference frame, a nonlinear rotor flux observer is developed which is also capable of motor resistances and rotor speed simultaneously estimation. Moreover, a useful method is introduced for dc offset compensation which is a major problem of ac drives especially at low speeds. The proposed control idea is experimentally implemented in real time using a CPLD board synchronized with a personal computer. Simulation and experimental results are finally presented to confirm the validity and effectiveness of the proposed method.

  8. Maximum torque per ampere control of sensorless induction motor drives with dc offset and parameter compensation

    Field orientation control of induction machine (IM) drives is a well-known strategy which has a fast dynamic response. In this paper, the direct rotor flux field orientation control of speed sensorless IM drive is presented. A two level space vector modulation inverter is employed to generate the command stator voltage. In proposed control scheme, a maximum torque per ampere strategy is achieved using a so-called fast flux search method. Based on this method, for a given load torque and rotor speed, the magnitude of rotor reference flux is adjusted step by step until the effective value of stator current becomes minimized finally. In addition, using the IM fifth order model in the stationary reference frame, a nonlinear rotor flux observer is developed which is also capable of motor resistances and rotor speed simultaneously estimation. Moreover, a useful method is introduced for dc offset compensation which is a major problem of ac drives especially at low speeds. The proposed control idea is experimentally implemented in real time using a CPLD board synchronized with a personal computer. Simulation and experimental results are finally presented to confirm the validity and effectiveness of the proposed method.

  9. Measured speed versus true speed

    Perez, Israel

    2010-01-01

    The theoretical predictions, derived from the Lorentz and the Tangherlini transformations, for the one-way speed of any physical entity are confronted with the corresponding expressions for the one-way measured speed obtained from a gedanken experiment. The experiment demonstrates that, for an inertial frame $K'$ in motion relative to an inertial frame $K$ where the one-way speed of light is isotropic, even the special theory of relativity renders the one-way speed of light as function of the...

  10. Factors Influencing Drivers' Speeding Behaviour

    Wallén Warner, Henriette

    2006-01-01

    Every year many people all over the world are killed and severely injured in road traffic accidents. Even though driving too fast is a behaviour well known to contribute to both the number and the outcome of these accidents, drivers are still speeding. The general aim of this thesis, and its five empirical studies, is therefore to further the knowledge about drivers speeding behaviour by using the theory of planned behaviour and the model underpinning the driver behaviour questionnaire as fra...

  11. High Torque, Direct Drive Electric Motor Project

    National Aeronautics and Space Administration — Bear Engineering proposes to develop an innovative high torque, low speed, direct drive motor in order to meet NASA's requirements for such devices. Fundamentally,...

  12. High Torque, Direct Drive Electric Motor Project

    National Aeronautics and Space Administration — Bear Engineering proposes to advance the development of an innovative high torque, low speed, direct drive motor in order to meet NASA's requirements for such...

  13. Self-Commissioning of AC Motor Drives

    Odhano, Shafiq Ahmed

    2014-01-01

    In modern motion control and power conversion applications, the use of inverter-fed electrical machines is fast growing with continuous development in the field of power electronics and drives. The Variable Voltage Variable Frequency (VVVF) supply for electrical machines gives superior performance in terms of speed control, efficiency and dynamics compared to the machines operated directly from the mains. In one of the most basic configurations, a drive system consists of a closed loop speed ...

  14. Hierarchical Control Strategy of Reactive Power for Wind Farm Based on the Front-End Speed Adjusting Wind Turbine%基于前端调速式风电机组的风电场无功分层控制策略

    燕尧; 董海鹰

    2015-01-01

    前端调速式风电机组具有较强的动态无功调节能力,针对由前端调速式风电机组组成的风电场存在随风电出力的变化引起的并网点电压波动问题,提出一种前端调速式风电场无功电压分层控制策略。该策略确定了风电场无功控制点的选取,利用风电场控制点电压偏差,通过整定控制得到整个风电场无功需求量,以风电场内有功网损最小为目标函数,采用改进的遗传算法优化分配给各台风机,并结合静止同步补偿器的无功输出来调节整个风电场的无功输出,达到维持控制点电压稳定的目的。最后以某一风电场的仿真结果验证了该策略的有效性和可行性。%The front-end speed adjusting wind turbine has strong dynamic reactive power regulation ability, aiming at prob-lems in the wind farm which consists of the front-end speed adjusting wind turbine existing the grid connection node voltage fluctuation which is caused by the change of wind power, this paper proposes a hierarchical control strategy of reactive voltage in the front-end speed adjusting wind farm.The strategy firstly determines selection of the reactive power control point in the wind farm, utilizes the voltage deviation of the wind farm control point, and obtains reactive power demand of the whole wind farm with the tuning control.The minimum real power loss of the wind farm is used as the objective function, based on the im-proved genetic algorithm optimization, and combines the reactive power output of the static synchronous compensator to adjust the reactive power output of the whole wind farm, so as to achieve the purpose of maintaining the voltage stability of the control point.The simulation results prove the feasibility and effectiveness of the strategy.

  15. Hierarchical control strategy of reactive power for wind farm based on the composition of the front-end speed adjusting wind turbine%基于前端调速式风电机组的风电场无功分层控制策略*

    燕尧; 董海鹰

    2015-01-01

    前端调速式风电机组具有较强的动态无功调节能力,针对由前端调速式风电机组组成的风电场存在随风电出力的变化而引起的并网点电压波动的问题,提出了一种前端调速式风电场无功电压分层控制策略。该策略首先确定了风电场无功控制点的选取,利用风电场控制点电压偏差,通过整定控制得到整个风电场无功需求量,以风电场内有功网损最小为目标函数,采用改进的遗传算法优化分配给各台风机,并结合静止同步补偿器的无功输出来调节整个风电场的无功输出,达到维持控制点电压稳定的目的。最后以某一风电场的仿真结果验证了该策略的有效性和可行性。%The front-end speed adjusting wind turbine has strong dynamic reactive power regulation ability. Aiming at the wind farm with the front-end speed adjusting wind turbine exists grid connection node voltage fluctuation problem caused by the change of wind power, a hierarchical control strategy of reactive voltage in the front-end speed adjusting wind farm is proposed. The strategy determines the selection of the reactive power control point in the wind farm, utilizes the voltage deviation of the wind farm control point, and obtains the reactive power demand of the whole wind farm by the tuning control. The minimum real power loss of the wind farm is used as objective function to allocate to each wind turbine based on the optimized and improved genetic algorithm. The strategy combines the reactive power output of the Static Synchronous Compensator to adjust the reactive power output of the whole wind farm and thus to achieve the purpose of maintaining the voltage stability of the control point. The simulation results prove the feasibility and effectiveness of the strategy.

  16. 基于前端调速式风电机组的风电场无功分层控制策略*%Hierarchical control strategy of reactive power for wind farm based on the composition of the front-end speed adjusting wind turbine

    燕尧; 董海鹰

    2015-01-01

    The front-end speed adjusting wind turbine has strong dynamic reactive power regulation ability. Aiming at the wind farm with the front-end speed adjusting wind turbine exists grid connection node voltage fluctuation problem caused by the change of wind power, a hierarchical control strategy of reactive voltage in the front-end speed adjusting wind farm is proposed. The strategy determines the selection of the reactive power control point in the wind farm, utilizes the voltage deviation of the wind farm control point, and obtains the reactive power demand of the whole wind farm by the tuning control. The minimum real power loss of the wind farm is used as objective function to allocate to each wind turbine based on the optimized and improved genetic algorithm. The strategy combines the reactive power output of the Static Synchronous Compensator to adjust the reactive power output of the whole wind farm and thus to achieve the purpose of maintaining the voltage stability of the control point. The simulation results prove the feasibility and effectiveness of the strategy.%前端调速式风电机组具有较强的动态无功调节能力,针对由前端调速式风电机组组成的风电场存在随风电出力的变化而引起的并网点电压波动的问题,提出了一种前端调速式风电场无功电压分层控制策略。该策略首先确定了风电场无功控制点的选取,利用风电场控制点电压偏差,通过整定控制得到整个风电场无功需求量,以风电场内有功网损最小为目标函数,采用改进的遗传算法优化分配给各台风机,并结合静止同步补偿器的无功输出来调节整个风电场的无功输出,达到维持控制点电压稳定的目的。最后以某一风电场的仿真结果验证了该策略的有效性和可行性。

  17. 基于前端调速式风电机组的风电场无功分层控制策略%Hierarchical Control Strategy of Reactive Power for Wind Farm Based on the Front-End Speed Adjusting Wind Turbine

    燕尧; 董海鹰

    2015-01-01

    The front-end speed adjusting wind turbine has strong dynamic reactive power regulation ability, aiming at prob-lems in the wind farm which consists of the front-end speed adjusting wind turbine existing the grid connection node voltage fluctuation which is caused by the change of wind power, this paper proposes a hierarchical control strategy of reactive voltage in the front-end speed adjusting wind farm.The strategy firstly determines selection of the reactive power control point in the wind farm, utilizes the voltage deviation of the wind farm control point, and obtains reactive power demand of the whole wind farm with the tuning control.The minimum real power loss of the wind farm is used as the objective function, based on the im-proved genetic algorithm optimization, and combines the reactive power output of the static synchronous compensator to adjust the reactive power output of the whole wind farm, so as to achieve the purpose of maintaining the voltage stability of the control point.The simulation results prove the feasibility and effectiveness of the strategy.%前端调速式风电机组具有较强的动态无功调节能力,针对由前端调速式风电机组组成的风电场存在随风电出力的变化引起的并网点电压波动问题,提出一种前端调速式风电场无功电压分层控制策略。该策略确定了风电场无功控制点的选取,利用风电场控制点电压偏差,通过整定控制得到整个风电场无功需求量,以风电场内有功网损最小为目标函数,采用改进的遗传算法优化分配给各台风机,并结合静止同步补偿器的无功输出来调节整个风电场的无功输出,达到维持控制点电压稳定的目的。最后以某一风电场的仿真结果验证了该策略的有效性和可行性。

  18. A study on energy saving rate for variable speed condition of multistage centrifugal pump

    Suh, Sang-Ho; Rakibuzzaman; Kim, Kyung-Wuk; Kim, Hyoung-Ho; Yoon, In Sik; Cho, Min-Tae

    2015-11-01

    Centrifugal pumps are being widely used in many industrial and commercial applications. Many of these pumps are being operated at constant speed but could provide energy savings through adjustable speed operations. The purpose of this study was to get the energy saving rates of the multistage centrifugal pump with variable speed conditions. For this investigation an experimental set up of variable flow and pressure system was made to get energy saving rates and numerical analyses are applied to validate the pump performance. The energy saving and therefore the cost saving depends on the specific duty cycle of which the machine operates. Duty cycle is the proportion of time during which a component, device and system is operated. The duty cycle segmented into different flow rates and weighting the average value for each segment by the interval time. The system was operated at 50% or less of the pump capacity. The input power of the system was carried out by pump characteristics curve of each operating point. The energy consumption was done by the product of specific duty cycle and the input power of the system for constant speed and variable speed drive operation. The total energy consumed for constant speed drive pump was 75,770 kW.hr and for variable speed drive pump was 31,700 kW.hr. The total energy saving of the system was 44,070 kW.hr or 58.16% annually. So, this paper suggests a method of implementing an energy saving on variable-flow and pressure system of the multistage centrifugal pump.

  19. Detonation drive pellet injector

    Detonation drive pellet injector has been developed and tested. By this method the free piston is not necessary because the pellet accelerated the high pressure shock directly. In the experiment, the Teflon pellet (5 mm dia., 5 mm length) was accelerated by hydrogen, oxygen and dilution gas mixtured detonation. When the gas pressure was only 500 kPa and the mixture rates of hydrogen, oxygen and helium were 3:6:1 or 3:6:0, the Teflon pellet speed was up to 747 m/s. Typical experimental results over 300 kPa of the initial gas pressure range are 78--92% of the one-dimensional calculational values. It showed that the pellet could be accelerated by a relative low pressure gas. When the helium dilution rate is larger than 20%, it was often found the strong detonation of which speed is more than the Chapman-Jouguet speed. Then the pellet speed above 1,100 m/s was obtained

  20. Energy Optimal Control of Induction Motor Drives

    Abrahamsen, Flemming

    system. The dynamic performances were also evaluated in a vector controlled drive for CT applications. Based on these tests, the displacement power factor control and the direct air-gap flux control appeared to be best for small HVAC applications. Energy optimal control of medium-size drives was analyzed......This thesis deals with energy optimal control of small and medium-size variable speed induction motor drives for especially Heating, Ventilation and Air-Condition (HVAC) applications. Optimized efficiency is achieved by adapting the magnetization level in the motor to the load, and the basic...... purpose is demonstrate how this can be done for low-cost PWM-VSI drives without bringing the robustness of the drive below an acceptable level. Four drives are investigated with respect to energy optimal control: 2.2 kW standard and high-efficiency motor drives, 22 kW and 90 kW standard motor drives. The...

  1. Quantum effects in warp drives

    Finazzi Stefano

    2013-09-01

    Full Text Available Warp drives are interesting configurations that, at least theoretically, provide a way to travel at superluminal speed. Unfortunately, several issues seem to forbid their realization. First, a huge amount of exotic matter is required to build them. Second, the presence of quantum fields propagating in superluminal warp-drive geometries makes them semiclassically unstable. Indeed, a Hawking-like high-temperature flux of particles is generated inside the warp-drive bubble, which causes an exponential growth of the energy density measured at the front wall of the bubble by freely falling observers. Moreover, superluminal warp drives remain unstable even if the Lorentz symmetry is broken by the introduction of regulating higher order terms in the Lagrangian of the quantum field. If the dispersion relation of the quantum field is subluminal, a black-hole laser phenomenon yields an exponential amplification of the emitted flux. If it is superluminal, infrared effects cause a linear growth of this flux.

  2. Speed mathematics

    Handley, Bill

    2012-01-01

    This new, revised edition of the bestselling Speed Mathematics features new chapters on memorising numbers and general information, calculating statistics and compound interest, square roots, logarithms and easy trig calculations. Written so anyone can understand, this book teaches simple strategies that will enable readers to make lightning-quick calculations. People who excel at mathematics use better strategies than the rest of us; they are not necessarily more intelligent. With Speed Mathematics you'll discover methods to make maths easy and fun. This book is perfect for stud

  3. Adjustments and Depression

    Full Text Available ... to my SCI? How do I deal with depression and adjustment to my SCI? ☷ ▾ Page contents The ... the moment you are injured. Understanding adjustment and depression Adjustment to paralysis is a process of changing ...

  4. PERFORMANCE EVALUATION OF THREE-PHASE INDUCTION MOTOR DRIVE FED FROM Z-SOURCE INVERTER

    Bindeshwar Singh

    2011-03-01

    Full Text Available This paper presents a Z-source inverter which has been proposed as an alternative power conversion concept for adjustable speed AC drives. It is having both voltages buck and boost capabilities as they allow inverters to be operated in the shoot through state. It utilizes an exclusive Z-source network (LC component to DC-link in between maininverter circuit and the DC source (rectifier. By controlling the shoot-through duty cycle, the inverter system using IGBTs, reduces the line harmonics, improves power factor, increases reliability and extends output voltage range. The proposed strategy reduces harmonics, low switching stress power and low common mode noise.

  5. Short term Braking Capability during Power Interruptions for Integrated Matrix Converter-Motor Drives

    Klumpner, Christian; Blaabjerg, Frede

    2002-01-01

    The new trend in Adjustable Speed Drives (ASD) is to integrate the inverter and the motor into a single unit in order to reduce the production cost, the commissioning time and the physical size of the equipment. This last issue becomes more important, making the matrix converter topology more...... engages or to perform more effective a combined braking.This paper proposes a new method to provide short-term braking capability during a power outage for matrix converters. A braking chopper is needed in the clamp circuit, which allows for a drastically reduction of the capacitor size. The power flow in...

  6. Simplified drive system models for power system transient studies in industrial plants

    Chen, Peiyuan; Sannino, Ambra

    2007-01-01

    In order to simulate industrial plants for different power system transient studies, simplified adjustable speed drive (ASD) models are needed. For power system transient studies such as assessing the voltage dip ride-through capability of ASDs, detailed representation of semiconductor valve...... switching can be avoided, thereby making possible to increase the time step of the simulation. In this paper, simplified ASD models are developed and compared with corresponding detailed models. The performance of the simplified models is assessed when increasing the simulation step as much as possible...

  7. Control rod drives

    Purpose: To enable fine positioning by using an induction motor of a simple structure as a driving source and thereby improve the reliability of control rod drives. Constitution: A step actuator is directly coupled with an induction motor, in which the induction motor is connected by way of a pulse driving control circuit to an AC power source, while the step actuator is connected to a DC power source. When a thyristor is turned ON, the motor outputs a positive torque and rotates and starts to rotate in the forward direction. When the other thyristor is turned ON, the motor is applied with braking by a reverse excitation in a manner equivalent to the change for the exciting phase sequence. When the speed is lowered to a predetermined value, braking is actuated by the torque of the step actuator and the motor stops at a zero position or balanced position. In this way, braking is actuated from the decelerating step to the stopping with no abrasion and a highly accurate positioning is possible due to the characteristics of the step actuator. (Horiuchi, T.)

  8. Driving things

    Nevile, Maurice Richard

    2015-01-01

    I explore how participants organise involvement with objects brought into the car, relative to the demands of driving and social activity. Objects in cars commonly include phones or other technologies, food, body care products, texts, clothing, bags and carry items, toys, and even animals....... pp.155 ((http://www.infrastructure.gov.au/roads/safety/publications/2010/pdf/rsgr_2010001.pdf)) Nevile, M., Haddington, P., Heinemann, T., Rauniomaa, M. (Eds.) Interacting with objects: Language, materiality, and social activity. Amsterdam/Philadelphia: John Benjamins. Redshaw, S. (2008). In the...

  9. Algorithm of brush short-circuit coefficients of DC machines for extremely low speed drives%极低速驱动用直流电机电刷短路系数的算法

    张琪; 谢国栋; 黄苏融

    2008-01-01

    When a direct-current (DC) machine runs at extremely low speed or standstill, the reduction in the armature resistance and the armature flux linkage due to the short circuited coils by the brushes on the commutator should not be neglected. Taking this reduction effect into account, the average values of the reduction coefficients relate to the machine parameters in complicated forms. In this paper, an effective algorithm for the precise computation of the average values of these reduction coefficients is proposed. Furthermore, in the algorithm, the effect of the insulation thickness between the commutator segments and the multiplicity of the wave winding are considered for the first time. The proposed algorithm can also be accommodated into the computer-aided design (CAD) of a DC machine, which normally runs at extremely low speed or standstill.

  10. Train Operation Adjustment Based on Conflict Resolution for High-speed Rail%高速铁路单个列车运行冲突消解研究

    文超; 彭其渊; 陈芋宏

    2013-01-01

    为研究高速铁路列车运行冲突消解问题,提出了各类列车运行冲突单个冲突的消解策略.分析了平移运行线、交换运行线、变更停站和越行方案以及数学规划方法等4种冲突策略的含义.根据冲突消解代价计算的方法,以最小冲突消解代价为优化目标,研究了高速铁路到达间隔时间冲突和出发间隔时间冲突、区间冲突、到发线运用冲突运用平移运行线、交换运行线、变更停站和越行方案等三种策略进行冲突消解的方法和过程.%In order to study the issue of train running conflict resolution of high-speed rail, the strategies of single train running conflict resolution for various types of train running conflicts is proposed. The 4 conflict resolution strategies named parallel shift of trains running lines, exchange of trains running lines, change of stopping stations and overtaking scheme, mathematical programming method are analyzed. In according to the conflict resolution cost calculation method and aimed to the minimum conflict resolution cost, the conflict resolution method and process are studied. The conflict resolution of the arrival interval conflict, departure interval conflict, section occupation conflict, arrival and departure track utilization conflict are discussed on the basis the conflict resolution strategies of parallel shift of trains running lines, exchange of trains running lines, change of stopping stations and overtaking scheme.

  11. Control Strategy for a High Speed SRM Fed from a Photovoltaic Source

    Ahmed Said Oshaba

    2013-01-01

    High speed Switched Reluctance Motors (SRMs) have recently been gaining attention as contenders in many variable speed drive applications. This has also been stimulated by recent advances in power electronic technology which enables this drive system for many applications such as high speed water pump and space and military applications. This study presents the design and control of high speed four phases SRM suitable for high speed water pumping and other high speed variable load application...

  12. Rotor Speed Detection Method for Vector Control of Induction Motor without Speed Sensor Utilizing Slot Harmonics

    Kiyotake, Hirofumi; Shinohara, Katsuji; Yamamoto, Kichiro

    Speed sensorless vector controlled induction motor drives are the standard choice in many industrial applications, but this can hardly control torque and rotor speed at low speed. Recently, a method based on the high-frequency signal injection has been studied. This paper presents a method for suppressing the effects of the saturation saliency by using high pass filter, and a new approach to estimate the rotor speed. The effectiveness of these methods are demonstrated through experimental results showing both good suppression of saturation harmonics and good sensorless speed control at low speed.

  13. Digital control of electric drives

    Koziol, R; Szklarski, L

    1992-01-01

    The electromechanical systems employed in different branches of industry are utilized most often as drives of working machines which must be fed with electric energy in a continuous, periodic or even discrete way. Some of these machines operate at constant speed, others require wide and varying energy control. In many designs the synchronous cooperation of several electric drives is required in addition to the desired dynamic properties. For these reasons the control of the cooperation and dynamics of electromechanical systems requires the use of computers.This book adopts an unusual approach

  14. Pay as You Speed, ISA with incentives for not speeding

    Lahrmann, Harry Spaabæk; Agerholm, Niels; Tradisauskas, Nerius;

    2012-01-01

    the reduction of a 30% discount on the driver's car insurance premium, which therefore produced the name, Pay as You Speed. The ISA equipment consists of a GPS-based On Board Unit with a mobile phone connection to a web server. The project was planned for a three-year test period with 300 young car drivers......, but it never succeeded in recruiting that number of drivers. After several design changes, the project eventually went forward with 153 test drivers of all ages. This number represents approximately one thousandth of all car owners in the proving ground of North Jutland in Denmark. Furthermore the project......The Intelligent Speed Adaptation (ISA) project we describe in this article is based on Pay as You Drive principles. These principles assume that the ISA equipment informs a driver of the speed limit, warns the driver when speeding and calculates penalty points. Each penalty point entails...

  15. Speed checks on the CERN site

    2007-01-01

    In view of the significant number of speeding incidents that have been reported, CERN will shortly start to carry out speed checks on the site. The radar used for this purpose will show drivers the speed measured. The disciplinary measures taken against those exceeding the authorised limit (generally 50 k.p.h.) will include a ban from driving on the site for a minimum of one month. Maximilian Metzger
Secretary-General

  16. Visual scale factor for speed perception

    Colombet, Florent; Paillot, Damien; Merienne, Frédéric; KEMENY, Andras

    2011-01-01

    Speed perception is an important task depending mainly on optic flow that the driver must perform continuously to control his/her vehicle. Unfortunately it appears that in some driving simulators speed perception is under estimated, leading into speed production higher than in real conditions. Perceptual validity is then not good enough to study driver's behavior. To solve this problem, a technique has recently seen the light, which consists of modifying the geometric field of view (GFOV) whi...

  17. Risky driving and recorded driving offences: a 24-year follow-up study.

    Summala, Heikki; Rajalin, Sirpa; Radun, Igor

    2014-12-01

    Permanent individual differences in driver behavior and accident risk have long been under active debate. Cognitive and personality factors have correlated with risky driving indicators in cross-sectional studies, and prospective cohort studies are now increasingly revealing early antecedents of risky behavior and injury mortality in adult age, with connections to stable personality traits. However, long-term stability in driver behavior or accident involvement has not been documented in a general driver population.This study reports 24-year follow-up data from a study that compared the recorded offenses between 134 drivers stopped by the police because of sustained risky driving and 121 control drivers stopped at the same locations at the same time in 1987 (Rajalin, 1994. Accid. Anal. Prev., 26, 555-562). Data were compiled from national driver records and accident statistics for the same drivers again 24 years later, and their yearly mileage and speed behavior was requested in a mail survey. The results showed that the two groups of drivers sampled on one trip a quarter of a century ago still differ from each other. The offenders still have more entries in their driver record, also when adjusted for age and mileage (OR=1.59, CI=1.03-2.46), they still report in the survey that they drive faster and overtake other cars more often. The results show that individual differences in driver behavior persist for decades, perhaps for life. However, in this on-road sample, the effect seems to be moderated by occupation which also presumably explains the lower mortality among the offenders during this 24-year follow-up. PMID:25171522

  18. Naturalistic speeding data: Drivers aged 75 years and older.

    Chevalier, Anna; Chevalier, Aran John; Clarke, Elizabeth; Wall, John; Coxon, Kristy; Brown, Julie; Ivers, Rebecca; Keay, Lisa

    2016-09-01

    The data presented in this article are related to the research article entitled "A longitudinal investigation of the predictors of older drivers׳ speeding behavior" (Chevalier et al., 2016) [1], wherein these speed events were used to investigate older drivers speeding behavior and the influence of cognition, vision, functional decline, and self-reported citations and crashes on speeding behavior over a year of driving. Naturalistic speeding behavior data were collected for up to 52 weeks from volunteer drivers aged 75-94 years (median 80 years, 52% male) living in the suburban outskirts of Sydney. Driving data were collected using an in-vehicle monitoring device. Global Positioning System (GPS) data were recorded at each second and determined driving speed through triangulation of satellite collected location data. Driving speed data were linked with mapped speed zone data based on a service-provider database. To measure speeding behavior, speed events were defined as driving 1 km/h or more, with a 3% tolerance, above a single speed limit, averaged over 30 s. The data contains a row per 124,374 speed events. This article contains information about data processing and quality control. PMID:27294182

  19. Neural and Fuzzy Adaptive Control of Induction Motor Drives

    This paper proposes an adaptive neural network speed control scheme for an induction motor (IM) drive. The proposed scheme consists of an adaptive neural network identifier (ANNI) and an adaptive neural network controller (ANNC). For learning the quoted neural networks, a back propagation algorithm was used to automatically adjust the weights of the ANNI and ANNC in order to minimize the performance functions. Here, the ANNI can quickly estimate the plant parameters and the ANNC is used to provide on-line identification of the command and to produce a control force, such that the motor speed can accurately track the reference command. By combining artificial neural network techniques with fuzzy logic concept, a neural and fuzzy adaptive control scheme is developed. Fuzzy logic was used for the adaptation of the neural controller to improve the robustness of the generated command. The developed method is robust to load torque disturbance and the speed target variations when it ensures precise trajectory tracking with the prescribed dynamics. The algorithm was verified by simulation and the results obtained demonstrate the effectiveness of the IM designed controller

  20. Study of bus driving parameters on urban route

    Fuad DASHDAMIROV

    2011-01-01

    The article deals with bus traffic time and speed on stage and route in the whole. The factors affecting bus driving parameters are divided into groups. The factors of significant impact are found in each group. The method of consideration of such factors impact on driving parameters in timetable making, is proposed. The extent of impact of selected factors on bus driving time and speed is studied.

  1. Structural and acoustic noise radiated by CD drives

    Nijhof, Marten J.J.; Beltman, Willem M.

    2005-01-01

    Optical drives inside PCs operate at high speed, which may result in significant noise. These drives function both as airborne and structural vibration sources. Three main paths can be distinguished through which noise is emitted to the surroundings: (1) the vibrations of the front of the drive emit

  2. 银行授信影响了资本结构动态调整速度吗?--考虑样本选择偏误的实证分析%Do Lines of Credit Affect Capital Structure Adjustment Speed? Evidence from Dynamic Panel with Sample Selection

    常亮

    2015-01-01

    With the panel data of Chinese listed firms during the time period of 2001—2011, this paper empirically studies the effect of credit lines on the capital structure adjustment speed, based on the theoretical assumption that bank lines of credit could reduce financial constraints so as to reduce adjustment costs. Traditional dynamic panel estimation are flawed to the bias of sample selection, since credit firms are selected according to firm size and investment opportunity. This paper uses dynamic panel model with sample selection to overcome these shortcomings. The results show that credit firms perform a much faster speed of capital structure adjustment comparing with non-credit firms.%银行授信可以通过缓解企业融资约束来降低企业的资本结构调整成本,从而有效提高资本结构的动态调整速度。但同时,企业能否获得银行授信,受到公司规模、投资机会等因素的影响,具有明显的样本选择性。因此,本文基于中国上市公司2001—2011年数据,在控制了授信的样本选择偏误的条件下,得到以下可信的证据:获得授信的公司表现出较快的调整速度,而不控制样本选择偏误的普通动态面板方法会使得估计有偏。本文不仅为资本结构的动态权衡理论提供了支持,同时也突出了在分组回归中控制样本选择偏误的重要性。

  3. Supersymmetry Breaking Casimir Warp Drive

    Obousy, R K

    2005-01-01

    Within the framework of brane-world models it is possible to account for the cosmological constant by assuming supersymmetry is broken on the 3-brane but preserved in the bulk. An effective Casimir energy is induced on the brane due to the boundary conditions imposed on the compactified extra dimensions. It will be demonstrated that modification of these boundary conditions allows a spacecraft to travel at any desired speed due to a local adjustment of the cosmological constant which effectively contracts/expands space-time in the front/rear of the ship resulting in motion potentially faster than the speed of light as seen by observers outside the disturbance.

  4. Speed Choice and Curve Radius on Rural Roads

    Rimme, Nicolai; Nielsen, Lea; Kjems, Erik;

    2016-01-01

    In most developed countries the majority of serious injured and fatalities in traffic accidents can be associated with driving in rural areas. A significant part of these incidents can be connected to the alignment of the road and an inappropriate speed choice. Often are curved alignments marked...... with informative speed-calming measures as traffic signs, reflectors or surface painting. However, it has been the hypothesis that people are reducing their speed insufficiently and are driving too fast in most curved alignments – especially when they are driving there frequently. By knowing the speed...

  5. Effects of chewing gum on driving performance as evaluated by the STISIM driving simulator

    Yoo, Ingyu; Kim, Eun-Joo; Lee, Joo-Hyun

    2015-01-01

    [Purpose] The purpose of this study was to determine the effects of chewing gum on driving performance in a driving simulator. [Subjects] In total, 26 young licensed drivers participated. [Methods] The driving scenario was typical of an urban environment: a single-carriageway, two-way road consisting of a mix of curved and straight sections, with considerable levels of traffic, pedestrians, and parked cars. Mean distance driven above the speed limit, lane position, mean distance driven across...

  6. IMPLEMENTATION AND STUDY OF BLDC MOTOR DRIVE SYSTEM

    Amol R. Sutar*, G. G. Bhide, J. J. Mane

    2016-01-01

    The BLDC motor  is an electronically commutated dc motor becoming very popular in many applications. There are various speed control methods used for BLDC motor. The performance of BLDC motor drives can be improved using sensored control techniques over sensorless technology. This paper presents Brushless Direct Current motor drive system and its sensored speed control technique with PWM.  Advantages and limitations of sensorless techniques are reviewed and then, sensored speed cont...

  7. 1.5MW低风速风力发电机组主传动系统设计及动力学分析%Design and dynamic analysis of main driving system for 1.5MW low-speed wind turbine

    黄宜森; 顾佥; 刘松超

    2012-01-01

    低风速风力发电机组具有广阔的市场前景,其主传动系统的设计和分析是整个风机研发的关键技术之一.通过对风机各种传动系统结构形式的分析、对比和优化,设计了适于1.5 MW低风速风力发电机组的最佳传动方案,即内置式主轴、二级行星加一级平行轴齿轮传动的结构形式.采用多体动力学软件SIMPACK建立了该风机主传动系统的精确模型,找出系统的固有频率及激振源,并进行共振分析;对共振危险点进行时域仿真,根据仿真结果研究振动对风机系统的影响.最后根据系统的动态特性分析结果,验证所设计的主传动系统的可靠性.%Low-speed wind generate turbine has a broad market prospect, the design and analysis of main driving system are the key technologies in the development of wind turbines. In this paper, a optimal main driving system was designed for 1.5 MW low-speed wind generate turbine through kinds of analysis,comparison and optimize, which are. Built-in main shaft, the secondary planet gear stages plus primary parallel gear stage. An accurate MBS model of main driving system is set up by SIMPACK software. All natural frequencies and vibration focus are found out and the NMR is performed. The danger frequencies are checked by time domain simulation, the influence of vibration on wind turbine system based on the simulation result. The dynamic characteristics of drive train are used to verify the reliability of the design.

  8. Indicators of Simulated Driving Skills in Adolescents with Autism Spectrum Disorder

    Sherrilene Classen PhD, MPH, OTR/L, FAOTA

    2013-08-01

    Full Text Available Adolescents are at high risk for motor vehicle crashes (MVCs. Teens with autism spectrum disorder (ASD may have an even greater risk for MVCs due to impaired visual, cognitive, and motor skills critical for driving. This prospective two group study demonstrated the demographic, clinical, and simulated driving skill differences of seven adolescents with ASD (mean age = 15.14, SD ±1.22 compared to 22 healthy controls (HC (mean age = 14.32, SD ±.72 through a comprehensive driving evaluation (CDE conducted by an occupational therapist certified driving rehabilitation specialist (OT-CDRS. Adolescents with ASD performed poorer on right eye acuity (Fischer’s (F = 13.44, p = .003, cognition (Mann-Whitney Statistic (U = 29.00, p = .01, visual motor integration (U = 27.50, p = .01, motor coordination (U = 5.00, p = .001, operational skills for managing simulator controls (U = 4.00, pU = 30.50, p = .02, speed regulation (U = 13.50, p = .001, lane maintenance (U = 34.00, p = .03, signaling (U = 38.50, p = .03, and adjustment to stimuli (U = 9.00, pU = 5.00, pConclusion. Compared to the HC, adolescents with ASD performed worse on visual, cognitive, motor, simulator operational, and fitness to drive skills, suggesting that an OT-CDRS may play an important role in assessing teens with ASD before they pursue traditional driver’s education.

  9. Supersymmetry Breaking Casimir Warp Drive

    Obousy, Richard K.

    2005-01-01

    Within the framework of brane-world models it is possible to account for the cosmological constant by assuming supersymmetry is broken on the 3-brane but preserved in the bulk. An effective Casimir energy is induced on the brane due to the boundary conditions imposed on the compactified extra dimensions. It will be demonstrated that modification of these boundary conditions allows a spacecraft to travel at any desired speed due to a local adjustment of the cosmological constant which effectiv...

  10. A Transformerless Hybrid Active Filter Capable of Complying with Harmonic Guidelines for Medium-Voltage Motor Drives

    Kondo, Ryota; Akagi, Hirofumi

    This paper presents a transformerless hybrid active filter that is integrated into medium-voltage adjustable-speed motor drives for fans, pumps, and compressors without regenerative braking. The authors have designed and constructed a three-phase experimental system rated at 400V and 15kW, which is a downscaled model from a feasible 6.6-kV 1-MW motor drive system. This system consists of the hybrid filter connecting a passive filter tuned to the 7th harmonic filter in series with an active filter that is based on a three-level diode-clamped PWM converter, as well as an adjustable-speed motor drive in which a diode rectifier is used as the front end. The hybrid filter is installed on the ac side of the diode rectifier with no line-frequency transformer. The downscaled system has been exclusively tested so as to confirm the overall compensating performance of the hybrid filter and the filtering performance of a switching-ripple filter for mitigating switching-ripple voltages produced by the active filter. Experimental results verify that the hybrid filter achieves harmonic compensation of the source current in all the operating regions from no-load to the rated-load conditions, and that the switching-ripple filter reduces the switching-ripple voltages as expected.

  11. Adjustments and Depression

    Full Text Available ... adjustment and depression Adjustment to paralysis is a process of changing one's thoughts and feelings and is ... stem cell research? What is the clinical trials process? Get support Ask us anything Get a peer ...

  12. Adjustments and Depression

    Full Text Available ... depression and adjustment to my SCI? How do I deal with depression and adjustment to my SCI? ☷ ▾ ... following an SCI? What are the secondary conditions? I have no health insurance, what are my options? ...

  13. Annual Adjustment Factors

    Department of Housing and Urban Development — The Department of Housing and Urban Development establishes the rent adjustment factors - called Annual Adjustment Factors (AAFs) - on the basis of Consumer Price...

  14. Adjustments and Depression

    Full Text Available ... course an adjustment period as you navigate your new normal. The most important point to remember is ... to rebuild one's identity and to find a new balance in relationships. The stages of adjustment can ...

  15. Do in-car devices affect experienced users' driving performance?

    Knapper, A.S. Hagenzieker, M.P. & Brookhuis, K.A.

    2014-01-01

    Distracted driving is considered to be an important factor in road safety. To investigate how experienced user's driving behaviour is affected by in-vehicle technology, a fixed-base driving simulator was used. 20 participants drove twice in a rich simulated traffic environment while performing secondary, i.e. mobile phone and navigation system tasks. The results show that mean speed was lower in all experimental conditions, compared to baseline driving, while subjective effort increased. Late...

  16. Sizing of a Right BLDC Motor for CNC Feed Drive

    P.Ram Kishore Kumar Reddy,; Mr. P.Nagasekhara Reddy,; M.Ramchandra Rao,; Professor, Department of Electrical and Electronics Engineering, KL University, Guntur-520002, Andhra Pradesh, India.

    2013-01-01

    This paper provides a technical aspects and design factors for selection of a right Brushless Direct Current (BLDC) motor for a CNC feed drive.To meet the most demanding requirements of CNC machine tools, robots and transfer lines in terms of productivity, accuracy and dynamic performance, brushless DC drives are very widely used. These drives employ brushless torque motors which are of high torque, low speed direct drive type. The performance and reliability of BLDC motor drivers have been i...

  17. Using Appropriate Speed Tables Regarding to the Speed Limit of Streets

    Amir Falamarzi

    2014-04-01

    Full Text Available In the present decade along the increasing trend of using private vehicles, calming the local streets and residential areas has been important for local authorities. There are many unsuccessful experiences of traffic calming implementations because of lacking knowledge and engineered assessment before implementing them. Considering the design speed of traffic, calming measure is an essential factor to employ these measures. Design speed of different size of speed humps is investigated in previous studies because of its circular shape but for speed tables it is unknown. In this research the design speeds of two common speed tables in the city of Tehran have been examined, 6.5 and 8.5 m speed table. For calculating the design speed of the speed tables, we asked 220 drivers to participate in our experiment by installing a GPS tracker in their vehicles and encouraging them to drive normally. Crossing speeds over 6.5 and 8.5 m speed tables have been analyzed by collecting totally 220 samples. We pick out 100 correct samples for each speed table and the 85th percentile speed has been calculated for them, consequently the results of 85th percentile calculation of the crossing speeds have been proposed as the design speeds. For 6.5 m speed table, design speed is calculated 41.5 km/h and for 8.5 m speed table, design speed is calculated 47.5 km/h. the comparison of recent findings and past finding of 9.5 m speed table which is used in Denmark with a design speed of 80 km/h reveals that 1 m increasing with the length of a 6.5 speed table plateau will result 3 km/h increase in its design speed. The findings of this research can help traffic calming experts to take in consideration of the relation between speed table physical characteristics and its design speed. Furthermore by finding the design speed of speed tables, we can choose suitable speed tables for streets with different speed limits according to the design speed of speed tables.

  18. Comparative performance analysis for digital regulators in series DC motor controlled drive

    Rezek, A.J.J.; Pinheiro, C.A.M.; Darido, T.Y.T; Da Silva, V.F.; Vicentini, O.H.S.; Assis, W. de O.

    2010-07-01

    The performance between conventional digital regulators and digital regulators was compared using fuzzy logic. A controlled DC drive was used for the analysis. Load torque and speed reference disturbances were used to compare the motor speed and current responses while using conventional and fuzzy PI digital regulators in the current and speed control loops of the drive.

  19. Speed Control Of Induction Motor Using Dspic30f2023

    M. S. Aspalli; Laxmi

    2013-01-01

    AC motor drives are widely used to control the speed of conveyor systems, blower speeds, pump speeds, machine tool speeds and other applications that require variable speed with variable torque. The main aim of the work is to design and develop an electronic system that can be used to control the speed of a three phase induction motor.The speed of the three phase induction motor can be controlled by various methods. The stator frequency control is one of the simplest methods to control the sp...

  20. Semiclassical instability of dynamical warp drives

    Finazzi, Stefano; Liberati, Stefano; Barceló, Carlos

    2009-01-01

    Warp drives are very interesting configurations in General Relativity: At least theoretically, they provide a way to travel at superluminal speeds, albeit at the cost of requiring exotic matter to exist as solutions of Einstein's equations. However, even if one succeeded in providing the necessary exotic matter to build them, it would still be necessary to check whether they would survive to the switching on of quantum effects. Semiclassical corrections to warp-drive geometries have been anal...

  1. Jump Testing and the Speed of Market Adjustment

    Rasmussen, Torben B.

    Asymptotic properties of jump tests rely on the property that any jump occurs within a single time interval no matter what the observation frequency is. Market microstructure effects in relation to news-induced revaluation of the underlying variable is likely to make this an unrealistic assumption...

  2. Design of a DSP-based servo speed controller

    Lu, Jialing

    1992-01-01

    The brushless servo drive is arguably the most important emerging drive category for robotics, machine tools and other applications. This places increasingly high demands on the servo motor and controller. The brushless servo drive is arguably the most important emerging drive category for robotics, machine tools and other applications. This places increasingly high demands on the servo motor and controller. Two PID design methods are studied for the speed controller, an "analog...

  3. Distractions in Everyday Driving

    ... while driving, which is one of the reasons distracted driving is such a big problem. Driver inattention is ... you’re doing any of these things while driving, you become distracted in ways that increase your risk of crashing. ...

  4. The Relationship between Road Design and Driving Behavior

    Abele, Liva; Møller, Mette

    2011-01-01

    Speed is a substantial factor contributing to road safety. Currently, speed reduction is mainly achieved through law enforcement and the implementation of traffic calming measures. An alternative speed reducing approach is to encourage drivers to voluntarily choose an appropriate driving speed....... Improving road infrastructure safety can be achieved by making roads forgiving and self-explaining. This could be done by clarifying the road design characteristics for each road category. The effect on driver behavior by varying road-shoulders and presence of roadside trees was tested by means of a fixed-driving...... simulator experiment. Speed and lateral position were used as performance indicators. The results indicated that shoulders might not be applied to decrease the speed on the experimental road stretch, but their presence cause drivers to drive closer to the road edge, hence eliminating the probability of head...

  5. Expressing Anger Is More Dangerous than Feeling Angry when Driving

    Qu, Weina; Dai, Mengnuo; Zhao, Wenguo; Zhang, Kan

    2016-01-01

    Anger is an emotion that drivers often feel and express while driving, and it is believed by researchers to be an important cause of dangerous driving behavior. In this study, the relationships between driving trait anger, driving anger expression, and dangerous driving behaviors were analyzed. The Driving Anger Scale (DAS) was used to measure driving trait anger, whereas the Driving Anger Expression (DAX) Inventory was used to measure expressions of driving anger. A sample of 38 drivers completed the DAS, DAX, and a driving simulation session on a simulator where their driving behaviors were recorded. Correlation analysis showed that the higher scores on the DAS were associated with longer durations of speeding in the simulator. The more participants expressed their anger in verbal and physical ways, the more likely they were to crash the virtual vehicle during the simulation. Regression analyses illustrated the same pattern. The findings suggest that, although trait anger is related to speeding, the passive expression of anger is the real factor underling traffic accidents. This study extends findings about the predictive effects of self-report scales of driving behaviors to behaviors recorded on a simulator. Thus, if in traffic safety propaganda, guiding drivers to use positive ways to cope with driving anger is recommended by our findings. PMID:27258144

  6. Expressing Anger Is More Dangerous than Feeling Angry when Driving.

    Weina Qu

    Full Text Available Anger is an emotion that drivers often feel and express while driving, and it is believed by researchers to be an important cause of dangerous driving behavior. In this study, the relationships between driving trait anger, driving anger expression, and dangerous driving behaviors were analyzed. The Driving Anger Scale (DAS was used to measure driving trait anger, whereas the Driving Anger Expression (DAX Inventory was used to measure expressions of driving anger. A sample of 38 drivers completed the DAS, DAX, and a driving simulation session on a simulator where their driving behaviors were recorded. Correlation analysis showed that the higher scores on the DAS were associated with longer durations of speeding in the simulator. The more participants expressed their anger in verbal and physical ways, the more likely they were to crash the virtual vehicle during the simulation. Regression analyses illustrated the same pattern. The findings suggest that, although trait anger is related to speeding, the passive expression of anger is the real factor underling traffic accidents. This study extends findings about the predictive effects of self-report scales of driving behaviors to behaviors recorded on a simulator. Thus, if in traffic safety propaganda, guiding drivers to use positive ways to cope with driving anger is recommended by our findings.

  7. Fundamental limitations on "warp drive" spacetimes

    Lobo, F S N; Lobo, Francisco S. N.; Visser, Matt

    2004-01-01

    "Warp drive" spacetimes are useful as "gedanken-experiments" that force us to confront the foundations of general relativity, and among other things, to precisely formulate the notion of "superluminal" communication. We verify the non-perturbative violation of the classical energy conditions of the Alcubierre and Natario warp drive spacetimes and apply linearized gravity to the weak-field warp drive, testing the energy conditions to first and second order of the non-relativistic warp-bubble velocity. We are primarily interested in a secondary feature of the warp drive that has not previously been remarked upon, if it could be built, the warp drive would be an example of a "reaction-less drive". For both the Alcubierre and Natario warp drives we find that the occurrence of significant energy condition violations is not just a high-speed effect, but that the violations persist even at arbitrarily low speeds. An interesting feature of this construction is that it is now meaningful to place a finite mass spaceshi...

  8. GCFR main helium circulator and electric drive

    One of the major objectives of the helium circulators for the gas-cooled fast breeder reactor (GCFR) is to achieve the highest possible operational reliability. This is no simple task considering the plant system integration requirements, auxiliary support systems, all possible transient requirements, and resulting complexity in supplying the driving power, primary coolant flow control, and lubrication and sealing. Therefore, the design of the circulator itself is highly dependent on the type of prime mover selected to drive the circulator, e.g., series turbine, parallel turbine, or electric motor. The circulator main drive has evolved from the series steam turbine drive into the variable-speed, synchronous electric motor drive mounted externally to the reactor and controlled by thyristor variable frequency controller. This design is a result of 18 months of joint effort by General Atomic Company and Westinghouse Electric Corporation

  9. KrF激光对高速飞片的驱动特性研究%Research on the driving characteristics of high speed flyer using KrF laser

    李业军; 王钊; 田宝贤; 梁晶; 韩茂兰; 陆泽; 汤秀章

    2014-01-01

    利用诱导空间非相干技术平滑的KrF准分子(248nm)激光驱动带有烧蚀层的平面靶,研究激光空间均匀性对产生完整飞片的影响,结果表明激光不均匀性在2%以下,能够产生完整的高速飞片,且完整飞片能够维持20ns以上不破裂;当激光不均匀性达到5%,激光引入流体力学不稳定性种子应很强,冲击波在靶内输运过程中不稳定性不断发展增强,到靶背时强到足以使飞片解体甚至气化,不能产生完整的飞片。为了获得尽可能高的飞片速度,采用激光与烧蚀层参数不匹配方法,使冲击波对飞片作多次加速。利用功率密度为1012 W/cm2的KrF激光与含50μm Kapton烧蚀层的5μm铝飞片作用,得到速度约10km/s的高速飞片,与模拟结果吻合得很好。%KrF excimer laser (248nm)has high spatial uniformity by using induced spatial in-coherence technology.After image relay and amplification by optical angular multiplexing tech-nology,non-uniformity of image surface of focal spot is 1 .6%.The spot spatial uniformity decreases with increasing distance of deviating image surface,the spatial non-uniformity is up to 5% at 3mm place deviating image surface.Laser directly drives planar target with ablation layer, the effects of laser spatial uniformity on flyer planarity and integrity were investigated.The results show when the non-uniformity of laser is below 2%,the integrity of inference fringes measured by laser velocity interferometer system for reflector keeps very well,the inference frin-ges last about 20ns after fringes jump.And the flyer can fly about 150 microns.The roughness of discontinuity is 62ps,which indicates that the shock wave planarity is good.The target debris deposited on sputtering film from the target of about 120mm is larger particles,which confirms the flyer has better integrity.When the laser non-uniformity is 5%,the interference fringes dis-appear completely after fringes jump

  10. Repatriation Adjustment: Literature Review

    Gamze Arman

    2009-12-01

    Full Text Available Expatriation is a widely studied area of research in work and organizational psychology. After expatriates accomplish their missions in host countries, they return to their countries and this process is called repatriation. Adjustment constitutes a crucial part in repatriation research. In the present literature review, research about repatriation adjustment was reviewed with the aim of defining the whole picture in this phenomenon. Present research was classified on the basis of a theoretical model of repatriation adjustment. Basic frame consisted of antecedents, adjustment, outcomes as main variables and personal characteristics/coping strategies and organizational strategies as moderating variables.

  11. Theory of adaptive adjustment

    Weihong Huang

    2000-01-01

    Full Text Available Conventional adaptive expectation as a mechanism of stabilizing an unstable economic process is reexamined through a generalization to an adaptive adjustment framework. The generic structures of equilibria that can be stabilized through an adaptive adjustment mechanism are identified. The generalization can be applied to a broad class of discrete economic processes where the variables interested can be adjusted or controlled directly by economic agents such as in cobweb dynamics, Cournot games, Oligopoly markets, tatonnement price adjustment, tariff games, population control through immigration etc.

  12. 77 FR 19127 - Defense Federal Acquisition Regulation Supplement; Inflation Adjustment of Threshold for...

    2012-03-30

    ... Regulation Supplement; Inflation Adjustment of Threshold for Acquisition of Right-Hand Drive Passenger Sedans... Year 2012 that requires that the statutory limitation on the acquisition of right-hand drive passenger sedans be included on the list of dollar thresholds subject to inflation adjustment. DATES:...

  13. Co-variability in Three Dimensions of Teenage Driving Risk Behavior: Impaired Driving, Risky and Unsafe Driving Behavior, and Secondary Task Engagement

    Simons-Morton, Bruce; Li, Kaigang; Ehsani, Johnathon; Vaca, Federico E.

    2016-01-01

    OBJECTIVE This research examined the extent to which teenagers who engaged in one form of risky driving also engaged in other forms and if risky driving measures were reciprocally associated over time. METHODS The data were from waves 1, 2 and 3 (W1, W2 and W3) of the NEXT Generation study, with longitudinal assessment of a nationally representative sample starting with 10th graders starting in 2009–2010. Three measures of risky driving were assessed in autoregressive and cross-lagged analyses: driving while alcohol/drug impaired, Checkpoints Risky Driving Scale (risky and unsafe driving), and secondary task engagement while driving. RESULTS In adjusted auto-regression models the risk variables, demonstrated high levels of stability, with significant associations observed across the three waves. However, associations between variables were inconsistent. DWI at W2 was associated with risky and unsafe driving at W3 (β = 0.21, p driving at W1 was associated with DWI at W2 (β = 0.20, p driving at W2 is associated with secondary task engagement at W3 (β = 0.19, p driving, with prospective associations between the Risky Driving Scale and the other measures, and reciprocal associations between all three variables at some time points. Secondary task engagement, however, appears largely to be an independent measure of risky driving. The findings suggest the importance of implementing interventions that addresses each of these driving risks. PMID:26514232

  14. Approach to Developing Predictive Capability for Hohlraum Drive and Symmetry

    Jones, O. S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-07-22

    Currently, we do not have the ability to predict the hohlraum drive and symmetry without requiring ad hoc adjustments to physics models. This document describes a plan for code improvements and focused physics validation experiments.

  15. The dynamic running law study on driving system of hydraulic winder

    彭佑多; 刘德顺; 郭迎福; 张永忠; 文西芹

    2002-01-01

    Dynamic running law of the hydraulic driving system decides the hoisting cage velocity curve in a hoisting cycle and is decided by the characteristic of the hydraulic driving system and by the operating speed of hoist driver. The paper studies the dynamic running law of hydraulic driving system, analyses the influence of driver operating speed on the dynamic running characteristic, and points out the reasonable driver operating speed to control the dynamic stress in rope and to reduce the oscillation of rope system.

  16. EMI performance comparison of two-level and three-level inverters in small dc-link capacitors based motor drives

    Maheshwari, Ram Krishan; Munk-Nielsen, Stig; Busquets-Monge, S.

    2012-01-01

    The size of passive components in an adjustable speed drive can be reduced by using small dc-link capacitors. The EMI filter in the drive also consists of passive components. The size of the filter can be reduced by using a three-level inverter, which can have low output voltage distortion. However......, the three-level inverter based on small dc-link capacitors requires a PWM strategy to maintain neutral-point voltage balance. In this paper, the common mode voltage, which is the determining factor for the EMI filter size, is analyzed for a virtual-vector-based PWM strategy. The common mode voltage...... presented. Results show that the conducted emission from the three-level inverter is lower than that of the two-level inverter. Thus, a three-level inverter requires a smaller EMI filter in motor drives with small dc-link capacitors....

  17. The Hardware Design of Parameter-Adjustable FIR Filter System

    Guosheng Xu

    2013-01-01

    This design using FPGA parallel architecture, high computing speed and high-speed reliability of USB2.0 interface, designed an FPGA + USB2.0 + computer FIR digital filter system, organically combining the speed of FPGA and flexibility of Computer through USB2.0 bus. The results demonstrated that the coefficients configuring of the system is easy, which can adjust the filter coefficients flexibly according to the actual demand, that it can effectively filter out the noise signals.

  18. The Effect of Speed Camera Warning Sign on Vehicle Speed in School Zones

    M.M. Rohani

    2014-12-01

    Full Text Available Driving too fast is one of the most prevalent factors that contribute to traffic crashes. In school zones, staying alert and obeying the posted speed limit especially during the school period are imperative for public safety, particularly involving children. Encouraging motorists to travel at safe speeds through the installation of yellow transverse bars at Seri Sabak Uni School and Pintas Puding School was found to be ineffective. Drivers were observed to have violated the 30 km/h speed limit and more seriously, driven over the speed limits of adjoining roads. Consequently, speed camera warning signs were erected as a pre-emptive measure to curtail speeding problems in the school zones. From impact studies carried out to measure the effectiveness of these signs, it was found that the speed camera warning signs were also not able to change driver behavior.

  19. ADJUSTABLE CHIP HOLDER

    2009-01-01

    An adjustable microchip holder for holding a microchip is provided having a plurality of displaceable interconnection pads for connecting the connection holes of a microchip with one or more external devices or equipment. The adjustable microchip holder can fit different sizes of microchips with ...

  20. Extended Driving Impairs Nocturnal Driving Performances

    Patricia Sagaspe; Jacques Taillard; Torbjorn Akerstedt; Virginie Bayon; Stéphane Espié; Guillaume Chaumet; Bernard Bioulac; Pierre Philip

    2008-01-01

    Though fatigue and sleepiness at the wheel are well-known risk factors for traffic accidents, many drivers combine extended driving and sleep deprivation. Fatigue-related accidents occur mainly at night but there is no experimental data available to determine if the duration of prior driving affects driving performance at night. Participants drove in 3 nocturnal driving sessions (3-5 am, 1-5 am and 9 pm-5 am) on open highway. Fourteen young healthy men (mean age [+/-SD] = 23.4 [+/-1.7] years)...

  1. Extended Driving Impairs Nocturnal Driving Performances

    SAGASPE, Patricia; Taillard, Jacques; Åkerstedt, Torbjorn; BAYON, Virginie; Espié, Stéphane; Chaumet, Guillaume; Bioulac, Bernard; Philip, Pierre

    2008-01-01

    Though fatigue and sleepiness at the wheel are well-known risk factors for traffic accidents, many drivers combine extended driving and sleep deprivation. Fatigue-related accidents occur mainly at night but there is no experimental data available to determine if the duration of prior driving affects driving performance at night. Participants drove in 3 nocturnal driving sessions (3–5am, 1–5am and 9pm–5am) on open highway. Fourteen young healthy men (mean age [±SD] = 23.4 [±1.7] years) partici...

  2. Reading Text While Driving

    Liang, Yulan; Horrey, William J.; Hoffman, Joshua D.

    2015-01-01

    Objective In this study, we investigated how drivers adapt secondary-task initiation and time-sharing behavior when faced with fluctuating driving demands. Background Reading text while driving is particularly detrimental; however, in real-world driving, drivers actively decide when to perform the task. Method In a test track experiment, participants were free to decide when to read messages while driving along a straight road consisting of an area with increased driving demands (demand zone)...

  3. HARMONIC DRIVE SELECTION

    Piotr FOLĘGA

    2014-03-01

    Full Text Available The variety of types and sizes currently in production harmonic drive is a problem in their rational choice. Properly selected harmonic drive must meet certain requirements during operation, and achieve the anticipated service life. The paper discusses the problems associated with the selection of the harmonic drive. It also presents the algorithm correct choice of harmonic drive. The main objective of this study was to develop a computer program that allows the correct choice of harmonic drive by developed algorithm.

  4. Oscillation control system for electric motor drive

    Slicker, J.M.; Sereshteh, A.

    1988-08-30

    A feedback system for controlling mechanical oscillations in the torsionally complaint drive train of an electric or other vehicle. Motor speed is converted in a processor to estimate state signals in which a plant model which are used to electronically modify the torque commands applied to the motor. 5 figs.

  5. Oscillation control system for electric motor drive

    Slicker, James M. (Union Lake, MI); Sereshteh, Ahmad (Union Lake, MI)

    1988-01-01

    A feedback system for controlling mechanical oscillations in the torsionally complaint drive train of an electric or other vehicle. Motor speed is converted in a processor to estimate state signals in which a plant model which are used to electronically modify thetorque commands applied to the motor.

  6. Speed Regulator for Permanent Magnet DC Boring Machine

    2000-01-01

    In this paper a variable-speed system for a loaded permanent magnet direct current boring machine (PMDCBM) is described in details. The voltage adjustment of PMDCBM is accomplished by means of solid state switch with a high gain Darlington transistor. The device designed possesses good variable speed characteristic and Iow loss at low speed. The speed can be regulated automatically to hold at an ideal value according to the load.

  7. Control Scheme of Z-Source Inverter Based BLDC Motor Drive System Using Modified Pulse Width Modulation Techniq

    S. Suresh Kumar,

    2014-01-01

    Full Text Available A modified pulse width modulation technique for Z-source inverter based BLDC motor is proposed and analyzed in this project.The Z-source inverter can be used as Buck/Boost converter with lower cost and high efficiency. BLDC motors are used in electric vehicles where portability and efficiency are required. This drive system provides advantages of both BLDC motors and Z-source inverter, and can be used in fuel cell system and other adjustable speed drive application. In this project principle of modified pulse width modulation technique is implemented and simulated. The model of a three phase Z-source inverter has been discussed based on modified pulse with modulation technique. The simulation of Z-source inverter based BLDC motor is done using the MATLAB/SIMULINK.

  8. Adaptive control schemes for improving dynamic performance of efficiency-optimized induction motor drives.

    Kumar, Navneet; Raj Chelliah, Thanga; Srivastava, S P

    2015-07-01

    Model Based Control (MBC) is one of the energy optimal controllers used in vector-controlled Induction Motor (IM) for controlling the excitation of motor in accordance with torque and speed. MBC offers energy conservation especially at part-load operation, but it creates ripples in torque and speed during load transition, leading to poor dynamic performance of the drive. This study investigates the opportunity for improving dynamic performance of a three-phase IM operating with MBC and proposes three control schemes: (i) MBC with a low pass filter (ii) torque producing current (iqs) injection in the output of speed controller (iii) Variable Structure Speed Controller (VSSC). The pre and post operation of MBC during load transition is also analyzed. The dynamic performance of a 1-hp, three-phase squirrel-cage IM with mine-hoist load diagram is tested. Test results are provided for the conventional field-oriented (constant flux) control and MBC (adjustable excitation) with proposed schemes. The effectiveness of proposed schemes is also illustrated for parametric variations. The test results and subsequent analysis confer that the motor dynamics improves significantly with all three proposed schemes in terms of overshoot/undershoot peak amplitude of torque and DC link power in addition to energy saving during load transitions. PMID:25820090

  9. Functional Diagram of High-Precision Drive with Variables

    V. A. Gane

    2014-07-01

    Full Text Available The robustness property determines sensitivity of drive quality to immeasurable deviations of its parameters and characteristics of disturbing influences. The paper shows that a standard drive has a local speed feedback in order to ensure robustness at a conversion rate. The feedback covers drive executive elements.The robustness has a special character only in respect of the straight chain conversion rate in the structure of the standard drive. Consequently, an actual problem is to ensure drive robustness in respect of other changing parameters and disturbing characteristics including characteristics of un-stationary character. 

  10. Optimal Control Development System for Electrical Drives

    Marian GAICEANU

    2008-08-01

    Full Text Available In this paper the optimal electrical drive development system is presented. It consists of both electrical drive types: DC and AC. In order to implement the optimal control for AC drive system an Altivar 71 inverter, a Frato magnetic particle brake (as load, three-phase induction machine, and dSpace 1104 controller have been used. The on-line solution of the matrix Riccati differential equation (MRDE is computed by dSpace 1104 controller, based on the corresponding feedback signals, generating the optimal speed reference for the AC drive system. The optimal speed reference is tracked by Altivar 71 inverter, conducting to energy reduction in AC drive. The classical control (consisting of rotor field oriented control with PI controllers and the optimal one have been implemented by designing an adequate ControlDesk interface. The three-phase induction machine (IM is controlled at constant flux. Therefore, the linear dynamic mathematical model of the IM has been obtained. The optimal control law provides transient regimes with minimal energy consumption. The obtained solution by integration of the MRDE is orientated towards the numerical implementation-by using a zero order hold. The development system is very useful for researchers, doctoral students or experts training in electrical drive. The experimental results are shown.

  11. Reflector driving device of FBR type reactor

    The present invention provides a reflector driving device which eliminates driving at outside and rapidly start-up and shuts down the reactor. Namely, the device has an electromagnetic holding mechanism attracted to a reactor core barrel by electromagnetic attracting force. Electromagnetic repulsion coils for generating instantaneous electromagnetic repulsion force are disposed between the reflector and the electromagnet retaining mechanism. The reflector is driven using inertia force of the electromagnetic repulsion force and the reflector. Then, the reflector driving device is attracted and held at a start-up position of the reactor upon start-up of the reactor. The reflector elevated by fluid pressure is secured at a position of the start-up of the reactor while having the reflector driving device as a stopper. The reflector moves at an extremely slow speed while being secured to the reflector driving device along with the elevation of the reflector driving device. As a result, a driving shaft sealing material which supports a conventional driving device at the outside and the reflector is eliminated thereby simplifying the structure of the outside of the reactor. (I.S.)

  12. COMPARISON OF ADJUSTABLE HIGH-PHASE ORDER INDUCTION MOTORS’ MERITS

    V.S. Petrushin

    2016-03-01

    Full Text Available Purpose. Development of mathematical models of adjustable electrical drives with high-phase order induction motors for their merits analysis at static and dynamical modes. Methodology. At the mathematical modeling main kinds of physical processes taking place in the high-phase order induction motors are considered: electromagnetic, electromechanical, energetic, thermal, mechanical, vibroacoustic ones. Besides, functional as well as mass, frame and value indicators of frequency converters are taking into account which permits to consider technical and economical aspects of the adjustable induction electrical drives. Creation of high-phase order induction motors’ modifications in possible on the base of a stock 3-phase motors of basic design. Polyphase supply of induction motors is guaranteed by a number of the adjustable electrical drives’ power circuits. Results. Modelling of a number of adjustable electrical drives with induction motors of different phase number working on the same load by its character, value and required adjustment range is carried out. At the utilization of the family of characteristics including mechanical ones at different adjustment parameters on which loading mechanism’s characteristics are superimposed regulation curves representing dependences of electrical, energetic, thermal, mechanical, vibroacoustic quantities on the motors’ number of revolutions are obtained. Originality. The proposed complex models of adjustable electrical drives with high-phase order induction motors give a possibility to carry out the grounded choice of the drive’s acceptable variant. Besides, they can be used as design models at the development of adjustable high-phase order induction motors. Practical value. The investigated change of vibroacoustic indicators at static and dynamical modes has been determined decrease of these indicators in the drives with number of phase exceeding 3.

  13. Stability Analysis of BLDC Motor Drive based on Input Shaping

    M.Murugan

    2013-10-01

    Full Text Available The main objective of this work is to analyze the brushless DC (BLDC motor drive system with input shaping using classical control theory. In this paper, different values of damping ratio are used to understand the generalized drive performance. The transient response of the BLDC motor drive system is analyzed using time response analysis. The dynamic behaviour and steady state performance of the BLDC motor drive system is judged and compared by its steady state error to various standard test signals. The relative stability of this drive system is determined by Bode Plot. These analysis spotlights that it is possible to obtain a finite-time setting response without oscillation in BLDC motor drive by applying input in four steps of different amplitude to the drive system. These analyses are helpful to design a precise speed control system and current control system for BLDC motor drive with fast response. The Matlab/Simulink software is used to perform the simulation.

  14. Macroeconomic Situations and Policy Adjustments in China

    Dongjun Mao

    2009-01-01

    China has achieved wholly rapid growth, with economic reform and opening-up, since 1978. But the macro-economy is instable and showing prosperity and inflation, and Recession and deflation repeatedly with many times. Excessive fluctuations in the economy are due to macroeconomic policies’ amendments and adjustments, too loose or tight. Economic growth speeds up with macroeconomic fluctuations slowing down in recent years. Improvements in macroeconomic policies have played an important role. 2...

  15. Intelligent Speed Adaptation for involuntary drivers

    Agerholm, Niels; Tradisauskas, Nerius; Juhl, Jens; Berthelsen, Kasper Klitgaard; Lahrmann, Harry

    2012-01-01

    The Danish Intelligent Speed Adaptation (ISA) trial ISA C included 26 commercial cars and 51 drivers a number of whom were involuntary. After a baseline period, ISA was activated for one year. The drivers should identify themselves with a personal key ID before driving. As well as being informative...

  16. Development of Traction Drive Motors for the Toyota Hybrid System

    Kamiya, Munehiro

    Toyota Motor Corporation developed in 2005 a new hybrid system for a large SUV. This system included the new development of a high-speed traction drive motor achieving a significant increase in power weight ratio. This paper provides an overview of the hybrid system, discusses the characteristics required of a traction drive motor, and presents the technologies employed in the developed motor.

  17. Factors Associated with Speeding Penalties in Novice Drivers

    Eensoo, Diva; Paaver, Marika; Harro, Jaanus

    2010-01-01

    Novice drivers are an important risk group in traffic and speed limit exceeding is one of the major risk factors for traffic collisions. In this paper we explore how impulsivity measures, driving skills and driving safety are associated with speed limit exceeding in novice drivers if described variables are measured on the same subjects. Participants of the study were 909 novice car-drivers (mean age 24.7(SD=7.5) years). Subjects filled Barratt Impulsivity Scale, Adaptive and Maladaptive Impu...

  18. Cascade Speed Control Of Dc Motor

    Anagha, Ranjith K; Anand C.P; Rahul Das; Anusha A.S

    2014-01-01

    Abstract: This paper presents a MATLAB aided Cascade designed controller to control and monitor the DC motor speed. First, design the driver circuit of the DC motor and use the microcontroller PIC16F877A to collect the feedback signals from the current sensor and optical encoder. The measured speed and current are serially transmitted to PC using RS232. By the MATLAB aided cascade controller, where inner loop is the current loop and outer loop is the speed loop, the parameters are adjusted to...

  19. Family Adjustment to Aphasia

    ... Public / Speech, Language and Swallowing / Disorders and Diseases Family Adjustment to Aphasia Richard S. was a senior manager ... It also presents a great challenge to the family. There may be tension among family members and ...

  20. Adjustments and Depression

    Full Text Available ... identity and to find a new balance in relationships. The stages of adjustment can include grieving, taking ... treatment options. Related pages What is a complete vs incomplete injury? What emergency procedures occur following an ...

  1. Adjustments and Depression

    Full Text Available ... thoughts and feelings and is something that takes time. The goal of adjusting is to rebuild one's ... updates about our impact > Get the Reeve newsletter International support > Pages in other languages Made with ♡ in ...

  2. Adjustments and Depression

    Full Text Available ... rebuild one's identity and to find a new balance in relationships. The stages of adjustment can include ... a peer mentor Advocate for change Fundraise with Team Reeve Champions Committee Volunteering About Us Our story ...

  3. A novel robust speed controller scheme for PMBLDC motor.

    Thirusakthimurugan, P; Dananjayan, P

    2007-10-01

    The design of speed and position controllers for permanent magnet brushless DC motor (PMBLDC) drive remains as an open problem in the field of motor drives. A precise speed control of PMBLDC motor is complex due to nonlinear coupling between winding currents and rotor speed. In addition, the nonlinearity present in the developed torque due to magnetic saturation of the rotor further complicates this issue. This paper presents a novel control scheme to the conventional PMBLDC motor drive, which aims at improving the robustness by complete decoupling of the design besides minimizing the mutual influence among the speed and current control loops. The interesting feature of this robust control scheme is its suitability for both static and dynamic aspects. The effectiveness of the proposed robust speed control scheme is verified through simulations. PMID:17544426

  4. PERFORMANCE OF ANN BASED INDIRECT VECTOR CONTROL INDUCTION MOTOR DRIVE

    A. K. Sharma,

    2007-09-01

    Full Text Available Indirect field orientation (IFO induction machine drives are increasingly employed in industrial drive systems, but the drive performance is often degrades. Motor works on best performance at certain voltage and frequency for certain loads. In this paper artificial neural network is used to predict the operating voltage and frequency when the load torque and speed going changed so motor efficiency is increased. Simulation and experimental results are shown to validate the scheme.

  5. PERFORMANCE OF ANN BASED INDIRECT VECTOR CONTROL INDUCTION MOTOR DRIVE

    A. K. Sharma,; R. A. Gupta; Laxmi Srivastava

    2007-01-01

    Indirect field orientation (IFO) induction machine drives are increasingly employed in industrial drive systems, but the drive performance is often degrades. Motor works on best performance at certain voltage and frequency for certain loads. In this paper artificial neural network is used to predict the operating voltage and frequency when the load torque and speed going changed so motor efficiency is increased. Simulation and experimental results are shown to validate the scheme.

  6. Driving speed on thoroughfares in minor towns in Denmark

    Jørgensen, Morten; Agerholm, Niels; Lahrmann, Harry;

    Sammenhængen mellem trafikulykker og hastighed viser, at øget hastighed resulterer i flere og mere alvorlige trafikulykker. Tidligere undersøgelser har indikeret, at bilister overskrider hastighedsgrænsen på gennemfartsveje i mindre byer i Danmark. For at holde farten nede i bygennemfarter er der...

  7. Variable-Speed, Robust Synchronous Reluctance Machine Drive Systems

    Wang, Dong

    based on the variation signal injection. A common problem of these methods is that they require on-line calculation of the compensation gain factors, which are system parameters and operating condition dependent. To overcome these difficulties, a “virtual positive impedance” active damping method is...... implemented in the whole machine operation range. As a supplement to the proposed voltage lossless injection method, a machine inductance independent position estimation algorithm, which is suitable for arbitrary injection, is developed and tested. Compared with the flux linkage based position estimation...... algorithm, the proposed machine inductance in-dependent position estimation algorithm shows better dynamic response against the step load changes but requires more accurate signal sampling in steady state. Therefore, the flux linkage based position estimation algorithm with adaptive PI controllers is...

  8. KVA: Capital Valuation Adjustment

    Andrew Green; Chris Kenyon

    2014-01-01

    Credit (CVA), Debit (DVA) and Funding Valuation Adjustments (FVA) are now familiar valuation adjustments made to the value of a portfolio of derivatives to account for credit risks and funding costs. However, recent changes in the regulatory regime and the increases in regulatory capital requirements has led many banks to include the cost of capital in derivative pricing. This paper formalises the addition of cost of capital by extending the Burgard-Kjaer (2013) semi-replication approach to C...

  9. Dementia and driving

    ... this page: //medlineplus.gov/ency/patientinstructions/000028.htm Dementia and driving To use the sharing features on ... please enable JavaScript. If your loved one has dementia, deciding when they can no longer drive may ...

  10. Second-generation speed limit map updating applications

    Tradisauskas, Nerius; Agerholm, Niels; Juhl, Jens;

    2011-01-01

    Intelligent Speed Adaptation is an Intelligent Transport System developed to significantly improve road safety in helping car drivers maintain appropriate driving behaviour. The system works in connection with the speed limits on the road network. It is thus essential to keep the speed limit map...... used in the Intelligent Speed Adaptation scheme updated. The traditional method of updating speed limit maps on the basis of long time interval observations needed to be replaced by a more efficient speed limit updating tool. In a Danish Intelligent Speed Adaptation trial a web-based tool was therefore...... developed to give road authorities the opportunity to keep the speed limit map updated. However, the feedback from road authorities was insufficient. Hence a new web application based on Google Maps was made to provide easier speed limit updates for road authorities. The lessons learnt were that tools for...

  11. RESEARCH OF DESIGN’S PARAMETERS OF DRIVE MECHANISM OF RA 14 DOBBY AND DEVELOPMENT OF THE DRIVE MECHANISM

    ABDULLA Gabil; SERDAR, Serap Gamze; RIHTIM Bilal; ABDULLAYEV, Rashid

    2013-01-01

    There are three different principles to perform shedding motion which are; cam mechanism, dobby controlled mechanism and jacquard controlled mechanism. A dobby mechanism consists of three main parts; drive mechanism, selection mechanism and mechanism for transferring motion to the frames. Rotary dobby mechanisms are being used in shedding process of high-speed weaving machines. In this paper, design and synthesis of a novel drive mechanism had been explained. The drive mechanism, which is use...

  12. The Attentional Demand of Automobile Driving Revisited: Occlusion Distance as a Function of Task- Relevant Event Density in Realistic Driving Scenarios

    Kujala, Tuomo; Mäkelä, Jakke; Kotilainen, Ilkka; Tokkonen, Timo

    2016-01-01

    Objective: We studied the utility of occlusion distance as a function of task-relevant event density in realistic traffic scenarios with self-controlled speed. Background: The visual occlusion technique is an established method for assessing visual demands of driving. However, occlusion time is not a highly informative measure of environmental task-relevant event density in self-paced driving scenarios because it partials out the effects of changes in driving speed. Method: Self-determi...

  13. Gear bearing drive

    Weinberg, Brian (Inventor); Mavroidis, Constantinos (Inventor); Vranish, John M. (Inventor)

    2011-01-01

    A gear bearing drive provides a compact mechanism that operates as an actuator providing torque and as a joint providing support. The drive includes a gear arrangement integrating an external rotor DC motor within a sun gear. Locking surfaces maintain the components of the drive in alignment and provide support for axial loads and moments. The gear bearing drive has a variety of applications, including as a joint in robotic arms and prosthetic limbs.

  14. Universal drive unit

    Sehnálek, Lubomír

    2011-01-01

    This document deal with design of universal driving unit. For the final solution is required driving unit which will be controled with help of sensory unit placed on the chassis of driving unit. In theoretical part of this labour are examined possibilities of a power, electric motor operation by PWM, kind of chassis and odometry which could be taken into account. From this section is finally chosen concrete configuration which is then described in chapter concerned oneself with driving unit d...

  15. Semiclassical instability of dynamical warp drives

    Warp drives are very interesting configurations in general relativity: At least theoretically, they provide a way to travel at superluminal speeds, albeit at the cost of requiring exotic matter to exist as solutions of Einstein's equations. However, even if one succeeded in providing the necessary exotic matter to build them, it would still be necessary to check whether they would survive to the switching on of quantum effects. Semiclassical corrections to warp-drive geometries have been analyzed only for eternal warp-drive bubbles traveling at fixed superluminal speeds. Here, we investigate the more realistic case in which a superluminal warp drive is created out of an initially flat spacetime. First of all we analyze the causal structure of eternal and dynamical warp-drive spacetimes. Then we pass to the analysis of the renormalized stress-energy tensor (RSET) of a quantum field in these geometries. While the behavior of the RSET in these geometries has close similarities to that in the geometries associated with gravitational collapse, it shows dramatic differences too. On one side, an observer located at the center of a superluminal warp-drive bubble would generically experience a thermal flux of Hawking particles. On the other side, such Hawking flux will be generically extremely high if the exotic matter supporting the warp drive has its origin in a quantum field satisfying some form of quantum inequalities. Most of all, we find that the RSET will exponentially grow in time close to, and on, the front wall of the superluminal bubble. Consequently, one is led to conclude that the warp-drive geometries are unstable against semiclassical backreaction.

  16. A 7-year dataset for driving and evaluating snow models at an Arctic site (Sodankylä, Finland)

    Essery, Richard; Kontu, Anna; Lemmetyinen, Juha; Dumont, Marie; Ménard, Cécile B.

    2016-06-01

    Datasets derived from measurements at Sodankylä, Finland, for driving and evaluating snow models are presented. This is the first time that such complete datasets have been made available for a site in the Arctic. The continuous October 2007-September 2014 driving data comprise all of the meteorological variables required as inputs for physically based snow models at hourly intervals: incoming solar and longwave radiation, snowfall and rainfall rates, air temperature, humidity, wind speed and atmospheric pressure. Two versions of the driving data are provided: one using radiation and wind speed measurements made above the height of the trees around the clearing where the evaluation data were measured and one with adjustments for the influence of the trees on conditions close to the ground. The available evaluation data include automatic and manual measurements of bulk snow depth and snow water equivalent, and profiles of snow temperature, snow density and soil temperature. A physically based snow model is driven and evaluated with the datasets to illustrate their utility. Shading by trees is found to extend the duration of both modelled and observed snow cover on the ground by several days a year.

  17. A strategy for torque control for high-performance interior permanent magnet synchronous motor drives

    Zhong, L.; Rahman, M.F.; Lim, K.W. [New South Wales Univ., Kensington, NSW (Australia). School of Electrical Engineering

    1995-12-31

    Permanent magnet synchronous motors (PMSMs) fed by PWM inverters are widely used for industrial applications, such as servo, traction and spindle drives, because of their high air-gap flux density, high power/weight ratio, large torque/inertia ratio and so on. The interior permanent magnet synchronous motor (IPMSM) possesses special features for adjustable-speed operation which distinguish it from other classes of ac machines, especially surface permanent magnet synchronous motors (SPMSMs). Because of its special rotor configuration and pole saliency, IPMSM has relatively large armature inductances and is therefore more suitable for the constant power operation by the flux weakening control. On the other hand, the back EMF and variation of inductances are usually non-sinusoidal which causes the torque pulsations at low speed. This paper presents an instantaneous torque control scheme of IPMSM drive for both constant torque and constant power operations considering the limits of the available dc link voltage and current ratings of a given inverter. The compensation of the cogging torque of IPMSM is also studied. (author). 8 figs., 5 refs.

  18. STRESS; THE VULNERABILITY AND ASSOCIATION WITH DRIVING PERFORMANCE

    B. M.T. Shamsul

    2014-01-01

    Full Text Available Several factors may contribute to occurrence of road accidents which are human factors, vehicle factor, road factor and environmental factor. There has been recent evidence of a relationship between road accidents and emotional distress as well as fatigue. Monotonous and complex road environments are the road factor that relates to the internal factor within driver. The overall aim of this study was to compare driving stress, fatigue and driving error between complex and monotonous driving. This experimental study was carried out to measure the stress level, fatigue status and driving performance among hundred male drivers (20-59 years with driving experience more than one year. Cortisol concentration from respondents’ saliva was obtained to measure the stress level due to the driving test. Cortisols were measured using Salimetrics cortisol Enzyme Immunoassay kit (ELISA. Fatigue status was measured by using EEG test to the respondents while conducted the simulator driving test. Driving performance was measured based on the recorded data of Running-of-the Roads (RORI and Large Speed Variation (LSV index from the simulator system. This study found that there was a significant difference (p<0.05 between cortisol levels, EEG value and driving errors of monotonous and complex driving. Salivary cortisol level was found higher during monotonous driving compared to complex driving. Theta wave which indicates sleepy and fatigue condition was found higher on monotonous driving compared to other brainwaves which is alpha and beta state. RORI and LSV index was higher recorded during driving in complex road environments. The main implications of this study for road safety shows that monotonous driving had significantly induced driving stress and fatigue while complex driving lead to higher driving errors. Human factors and road factors could possibly put drivers in a higher risk to be involved in road accidents.

  19. High performance AC drives

    Ahmad, Mukhtar

    2010-01-01

    This book presents a comprehensive view of high performance ac drives. It may be considered as both a text book for graduate students and as an up-to-date monograph. It may also be used by R & D professionals involved in the improvement of performance of drives in the industries. The book will also be beneficial to the researchers pursuing work on multiphase drives as well as sensorless and direct torque control of electric drives since up-to date references in these topics are provided. It will also provide few examples of modeling, analysis and control of electric drives using MATLAB/SIMULIN

  20. Simple Driving Techniques

    Rosendahl, Mads

    2002-01-01

    -like language. Our aim is to extract a simple notion of driving and show that even in this tamed form it has much of the power of more general notions of driving. Our driving technique may be used to simplify functional programs which use function composition and will often be able to remove intermediate data......Driving was introduced as a program transformation technique by Valentin Turchin in some papers around 1980. It was intended for the programming language REFAL and used in metasystem transitions based on super compilation. In this paper we present one version of driving for a more conventional lisp...

  1. Semiclassical instability of dynamical warp drives

    Finazzi, Stefano; Barceló, Carlos

    2009-01-01

    Warp drives are very interesting configurations in General Relativity: At least theoretically, they provide a way to travel at superluminal speeds, albeit at the cost of requiring exotic matter to exist as solutions of Einstein's equations. However, even if one succeeded in providing the necessary exotic matter to build them, it would still be necessary to check whether they would survive to the switching on of quantum effects. Semiclassical corrections to warp-drive geometries have been analyzed only for eternal warp-drive bubbles traveling at fixed superluminal speeds. Here, we investigate the more realistic case in which a superluminal warp drive is created out of an initially flat spacetime. First of all we analyze the causal structure of eternal and dynamical warp-drive spacetimes. Then we pass to the analysis of the renormalized stress-energy tensor (RSET) of a quantum field in these geometries. While the behavior of the RSET in these geometries has close similarities to that in the geometries associate...

  2. Transistorized PWM inverter-induction motor drive system

    Peak, S. C.; Plunkett, A. B.

    1982-01-01

    This paper describes the development of a transistorized PWM inverter-induction motor traction drive system. A vehicle performance analysis was performed to establish the vehicle tractive effort-speed requirements. These requirements were then converted into a set of inverter and motor specifications. The inverter was a transistorized three-phase bridge using General Electric power Darlington transistors. The description of the design and development of this inverter is the principal object of this paper. The high-speed induction motor is a design which is optimized for use with an inverter power source. The primary feedback control is a torque angle control with voltage and torque outer loop controls. A current-controlled PWM technique is used to control the motor voltage. The drive has a constant torque output with PWM operation to base motor speed and a constant horsepower output with square wave operation to maximum speed. The drive system was dynamometer tested and the results are presented.

  3. Efficiency optimized control of medium-size induction motor drives

    Abrahamsen, F.; Blaabjerg, Frede; Pedersen, John Kim;

    2000-01-01

    The efficiency of a variable speed induction motor drive can be optimized by adaption of the motor flux level to the load torque. In small drives (<10 kW) this can be done without considering the relatively small converter losses, but for medium-size drives (10-1000 kW) the losses can not be disr...... robustness towards load disturbances may unnecessarily be reduced. Both displacement power factor and model-based efficiency optimizing control methods perform well in medium-size drives. The last strategy is also tested on a 22 kW drive with good results.......The efficiency of a variable speed induction motor drive can be optimized by adaption of the motor flux level to the load torque. In small drives (<10 kW) this can be done without considering the relatively small converter losses, but for medium-size drives (10-1000 kW) the losses can not be...... disregarded without further analysis. The importance of the converter losses on efficiency optimization in medium-size drives is analyzed in this paper. Based on the experiments with a 90 kW drive it is found that it is not critical if the converter losses are neglected in the control, except that the...

  4. CLOSED LOOP SPEED CONTROL OF DC MOTOR USING PWM

    Mangesh J Nemade

    2015-01-01

    In This work reveals the digital closed loop control system for speed control of DC motor using PWM technique. In present days the power semiconductor devices have co mpletely revolutionized the control of drives especially in the area of control usage of thyristors IGBT’s power MOSFET etc., was increased. The digital circuit can be interfaced to microcontroller. So that the speed can be controlled by Microcontroller there by making speed control of DC motor even more easil...

  5. Electric drive for an accelerator target with a timer for a pulsed fast reactor

    The invention is presented relating to electric drives with numerical control devices. An electric drive is described, comprising a synchronous drive motor, an electromagnetic clutch, a pulse speed transducer, and a numerical control device with a speed measuring unit, a counter, and a storage unit. The electric drive ensures cophasal rotation of a particle reflector with an attached target at the operating frequency of the accelarator, which is synchronized from the mains with a possibility of maintaining the reflector rotation at any preset invariable speed within a desired range

  6. High-efficiency control of brushless doubly-fed machines for wind turbines and pump drives

    The paper is concerned with vector control of a promising brushless doubly-fed reluctance machine (BDFRM) technology for generator and drive systems with limited adjustable speed ranges such as wind turbines or pump-alike installations. The BDFRM has been receiving increasing attention because of the low capital and operation and maintenance costs afforded by the partially-rated power electronics and the high reliability of brushless construction, while offering performance competitive to its well-known slip-ring counterpart, a doubly-fed induction machine. The comprehensive comparative studies have evaluated the performance of two robust control algorithms by computer simulations and experimentally on a custom-made BDFRM under the maximum torque per inverter ampere conditions for improved efficiency of electro-mechanical energy conversion

  7. Leakage current and commutation losses reduction in electric drives for Hybrid Electric Vehicle

    Miliani, El Hadj

    2014-06-01

    Nowadays, leakage current and inverter losses, produced by adjustable-speed AC drive systems become one of the main interested subject for researchers on Electric Vehicle (EV) and Hybrid Electric Vehicle (HEV) technology. The continuous advancements in solid state device engineering have considerably minimized the switching transients for power switches but the high dv/dt and high switching frequency have caused many adverse effects such as shaft voltage, bearing current, leakage current and electromagnetic interference (EMI). The major objective of this paper is to investigate and suppress of the adverse effects of a PWM inverter feeding AC motor in EV and HEV. A technique to simultaneously reduce the leakage current and the switching losses is presented in this paper. Based on a discontinuous space vector pulse width modulation (DSVPWM) and a modular switches gate resistance, inverter losses and leakage current are reduced. Algorithms are presented and implemented on a DSP controller and experimental results are presented.

  8. Speed Control of BLDC Motor Using DSP

    G.MadhusudhanaRao

    2010-03-01

    Full Text Available This paper proposed the speed control of brushless dc motor drive employing PWM technique using TMS320F240 digital signal processor. BLDC is widely used because of its high mechanical power density, simplicity and cost effectiveness. The complete controller for BLDC is developed using TMS 320F240 digital signal processor, which has thespecial features for digital motor control. A mathematical model of the drive system is developed to analyze the performance of the proposed drive. The hall sensor signals are used to sense the rotor position. A shunt resistor is used to sense the actual current entering into the motor. These hall signals, phase current sensing signal and the speed command are the input to the DSP. Both the outer velocity control loop and inner current control loop uses PI controller that has been implemented by programming in TMS320F240 DSP processor [8]. According to the input command, feedback command andcontrol algorithm, the PWM pulses for each phase generated by the DSP is given to IGBT driver. The output of the driver is 6 independent PWM pulses that have to be given to the corresponding gate of the six IGBTs power switches used in the three-phase bridge inverter whose output is given to the stator of the BLDC motor. The drive performance is studied for starting, speed reversal and load perturbation.

  9. A universal programmable driving circuit for spatial light modulators

    Lan, Wu; Ningmei, Yu; Yaohui, Zhang; Wenlong, Ma

    2009-07-01

    A universal programmable multi-quantum-well (MQW) spatial light modulator (SLM) driving circuit is developed. With a twice scanning, it can generate programmable signals to drive a non-linear MQW SLM by using a software preprocessing unit. By adjusting the switching network of the driving circuit, this circuit can reduce the switching noise and improve the output precision. The chip test results show that the driving voltage can swing from 0 to VDD, and its resolution could be close to 256 with a pixel area of only 65 × 65 μm2.

  10. A universal programmable driving circuit for spatial light modulators

    A universal programmable multi-quantum-well (MQW) spatial light modulator (SLM) driving circuit is developed. With a twice scanning, it can generate programmable signals to drive a non-linear MQW SLM by using a software preprocessing unit. By adjusting the switching network of the driving circuit, this circuit can reduce the switching noise and improve the output precision. The chip test results show that the driving voltage can swing from 0 to VDD, and its resolution could be close to 256 with a pixel area of only 65 x 65 μm2.

  11. Sustainable urban regime adjustments

    Quitzau, Maj-Britt; Jensen, Jens Stissing; Elle, Morten;

    2013-01-01

    The endogenous agency that urban governments increasingly portray by making conscious and planned efforts to adjust the regimes they operate within is currently not well captured in transition studies. There is a need to acknowledge the ambiguity of regime enactment at the urban scale. This direc...

  12. Auto Adjusting Astronomical Telescope

    Rohit R. Ghalsasi; Prof. N. D. Dhoot

    2014-01-01

    Astronomical telescope is powerful and basic tool for star or celestial observation. Here we proposed integrated system using Raspberry Pi for auto adjusting astronomical telescope. This integrated circuit helps to control stellar monitoring, stellar targeting, and tracking functions of telescope. Astro compass gives the direction of the celestial objects.

  13. Adjustments and Depression

    Full Text Available ... 7309 ☰ Living with Paralysis Get Support Get Involved Research Events Blog & Forum About Us Donate Living with Paralysis > Newly paralyzed > How do I deal with depression and adjustment to my SCI? How do I deal with depression and ...

  14. Auto Adjusting Astronomical Telescope

    Rohit R. Ghalsasi

    2014-04-01

    Full Text Available Astronomical telescope is powerful and basic tool for star or celestial observation. Here we proposed integrated system using Raspberry Pi for auto adjusting astronomical telescope. This integrated circuit helps to control stellar monitoring, stellar targeting, and tracking functions of telescope. Astro compass gives the direction of the celestial objects.

  15. A High Revolution Speed Noncontact Ultrasonic Motor Driven by a Non-Symmetrical Electrode

    YANG Bin; LIU Jing-Quan; CHEN Di; CAI Bing-Chu

    2005-01-01

    @@ A noncontact ultrasonic motor based on a non-symmetrical electrode is proposed. This motor has the advantages of using a simple driving electrode and having a high revolution speed. The revolution speed of its three-blade rotor can reach 5100rpm under a driving voltage of 20 V. A method operated easily is proposed to measure the output torque.

  16. Torque- and Speed Control of a Pitch Regulated Wind Turbine

    Rasila, Mika

    2003-07-01

    Variable speed operated wind turbines has the potential to reduce fatigue loads, compared to fixed speed wind turbines. With pitch controllable rotor blades limitation of the power at high wind speeds is obtained. The thesis describes different controlling aspects concerning wind turbines and how these together can be used to optimize the system's performance. Torque control is used in order to achieve reduction on the mechanical loads on the drive-train for low wind speeds and limitation of power output for high wind speeds. In the high wind speed interval torque control is effective in order to limit the output power if a sufficiently fast pitch actuator is used. In the middle wind speed interval filter utilization can be used to give a reference signal to the controller in order to reduce speed and torque variations.

  17. Kinematic synthesis of adjustable robotic mechanisms

    Chuenchom, Thatchai

    1993-01-01

    Conventional hard automation, such as a linkage-based or a cam-driven system, provides high speed capability and repeatability but not the flexibility required in many industrial applications. The conventional mechanisms, that are typically single-degree-of-freedom systems, are being increasingly replaced by multi-degree-of-freedom multi-actuators driven by logic controllers. Although this new trend in sophistication provides greatly enhanced flexibility, there are many instances where the flexibility needs are exaggerated and the associated complexity is unnecessary. Traditional mechanism-based hard automation, on the other hand, neither can fulfill multi-task requirements nor are cost-effective mainly due to lack of methods and tools to design-in flexibility. This dissertation attempts to bridge this technological gap by developing Adjustable Robotic Mechanisms (ARM's) or 'programmable mechanisms' as a middle ground between high speed hard automation and expensive serial jointed-arm robots. This research introduces the concept of adjustable robotic mechanisms towards cost-effective manufacturing automation. A generalized analytical synthesis technique has been developed to support the computational design of ARM's that lays the theoretical foundation for synthesis of adjustable mechanisms. The synthesis method developed in this dissertation, called generalized adjustable dyad and triad synthesis, advances the well-known Burmester theory in kinematics to a new level. While this method provides planar solutions, a novel patented scheme is utilized for converting prescribed three-dimensional motion specifications into sets of planar projections. This provides an analytical and a computational tool for designing adjustable mechanisms that satisfy multiple sets of three-dimensional motion specifications. Several design issues were addressed, including adjustable parameter identification, branching defect, and mechanical errors. An efficient mathematical scheme for

  18. Control of Electric Drives in the Best Efficiency Region of Pumping System

    Bakman Ilja

    2014-10-01

    Full Text Available The paper concentrates on improving the efficiency of the pumping system in which pumps are run by variable speed drives. The method is applicable to system consisting of several centrifugal pumps. Problems arising from running the pumps outside the optimal efficiency region are discussed. Common principles of operation and control of typical boosting pumping station are represented. Methods of regulation of productivity of the system are described. The proposed method is based on prediction of future efficiency of pumps before making adjustments of pumping system productivity. The proposed method is basing on tracking the working point of pump on efficiency graph. Monitoring the location of working point vs. efficiency graph enables to evaluate its current and future distances from the best efficiency point of the pump. Knowing the current number of running pumps it is possible to predict the location of working point after adjustment of productivity of the system. Ability to predict the increase or decrease of efficiency enables to enhance the adjustment of productivity of the system. Methods of graphical analysis of working state of the pumping system are representing topic for future research.

  19. Fundamental limitations on 'warp drive' spacetimes

    'Warp drive' spacetimes are useful as 'gedanken-experiments' that force us to confront the foundations of general relativity, and among other things, to precisely formulate the notion of 'superluminal' communication. After carefully formulating the Alcubierre and Natario warp drive spacetimes, and verifying their non-perturbative violation of the classical energy conditions, we consider a more modest question and apply linearized gravity to the weak-field warp drive, testing the energy conditions to first and second orders of the warp-bubble velocity, v. Since we take the warp-bubble velocity to be non-relativistic, v << c, we are not primarily interested in the 'superluminal' features of the warp drive. Instead we focus on a secondary feature of the warp drive that has not previously been remarked upon-the warp drive (if it could be built) would be an example of a 'reaction-less drive'. For both the Alcubierre and Natario warp drives we find that the occurrence of significant energy condition violations is not just a high-speed effect, but that the violations persist even at arbitrarily low speeds. A particularly interesting feature of this construction is that it is now meaningful to think of placing a finite mass spaceship at the centre of the warp bubble, and then see how the energy in the warp field compares with the mass-energy of the spaceship. There is no hope of doing this in Alcubierre's original version of the warp field, since by definition the point at the centre of the warp bubble moves on a geodesic and is 'massless'. That is, in Alcubierre's original formalism and in the Natario formalism the spaceship is always treated as a test particle, while in the linearized theory we can treat the spaceship as a finite mass object. For both the Alcubierre and Natario warp drives we find that even at low speeds the net (negative) energy stored in the warp fields must be a significant fraction of the mass of the spaceship

  20. The Design of Sport Bicycle Speed Odometer

    Dongbing Liu

    2013-04-01

    Full Text Available As bicycle sport equipment, a sport bike needs a speed and distance measuring device, due to the characteristic of road cycling, thereby mastering the state of motion. According to external conditions such as temperature, wind speed, the bike can make the appropriate adjustment to achieve the best movement effect. The bicycle speed odometer is a major accessibility tool that satisfies with needs of the people with fast development. This study elaborated a bike speed odometer design based on Hall element, taking AT89C52 single chip as the core, measuring speed with A44E Hall sensor, to finish the bike mileage/speed measurement and statistics by displaying bike mileage and speed in real time. By using the Hall elements, the hardware of speed odometer input the number of pulse of per circle into the single-chip computer system. Then the signal processed by the single-chip computer displays. The software is programmed with assembly language and modular design idea. The design of the hardware circuit is simple and the subroutine has universal property, which fully meet the design requirements and possess a wide range of application and dissemination value.

  1. A Novel Motor-Speed-Regulation Method

    Huang Zhou

    2016-01-01

    Full Text Available The traditional doubly-fed motor has less reliability because it needs carbon brushes and sliding rings which are not highly reliable. The brushless doubly-fed machine costs a lot for its framework requires special designing and processing. To overcome the disadvantages of the two kinds of motors, this paper focuses on a novel method of motor speed regulation which is based on rotating feeding. The motor speed changing around its rated speed can be realized based on the method without any carbon brush or sliding ring on the prosaic electrical motors. On the basis of the full controlled thyristor rectifying bridge structure, the basic idea is introduced; the advantages and disadvantages of this method are analyzed. This kind of systems can replace the brushed or brushless double-fed systems. They are very suitable for driving fans or pumps, or power-generating systems with variable speed constant frequency such as wind power or water power generating systems.

  2. Pace yourself: Improving time-saving judgments when increasing activity speed

    Eyal Peer

    2013-03-01

    Full Text Available The time-saving bias describes people's tendency to misestimate the time they can save by increasing the speed in which they perform an activity such as driving or completing a task. People typically underestimate time saved when increasing from a low speed and overestimate time saved when increasing from an already high speed. We suggest that this bias is the result of people's failure to recognize the curvilinear relationship between increasing speed and reducing activity time: As initial speed rises, the same speed increases will yield smaller reductions in time. We explore a new technique to de-bias these faulty estimations: converting measurements of speed to a pace measure (e.g., minutes per fixed distance. Utilizing common driving scenarios, we show that participants who received pace data made more accurate estimations of journey duration at various speeds, time-savings at various speed increases and the required speed to complete a journey.

  3. Evaluation, Transformation, and Extraction of Driving Cycles and Vehicle Operations

    Nyberg, Peter

    2013-01-01

    A driving cycle is a representation of how vehicles are driven and  is usually represented by a set of data points of vehicle speed  versus time.  Driving cycles have been used to evaluate vehicles for  a long time. A traditional usage of driving cycles have been in  certification test procedures where the exhaust gas emissions from  the vehicles need to comply with legislation. Driving cycles are now  also used in product development for example to size components or  to evaluate different t...

  4. Effects of chewing gum on driving performance as evaluated by the STISIM driving simulator.

    Yoo, Ingyu; Kim, Eun-Joo; Lee, Joo-Hyun

    2015-06-01

    [Purpose] The purpose of this study was to determine the effects of chewing gum on driving performance in a driving simulator. [Subjects] In total, 26 young licensed drivers participated. [Methods] The driving scenario was typical of an urban environment: a single-carriageway, two-way road consisting of a mix of curved and straight sections, with considerable levels of traffic, pedestrians, and parked cars. Mean distance driven above the speed limit, lane position, mean distance driven across the center line, and mean distance driven off the road were used as estimates of brake, accelerator, and steering control. The results were compared with those of a non-chewing gum control condition. [Results] The driving performance while chewing gum was significantly better: the mean distance driven above the speed limit was 26.61% shorter, and the mean distance driven off the road was 31.99% shorter. Lane position and mean distance driven across the center line did not differ significantly between the two conditions. [Conclusion] Chewing gum appears to enhance driving performance during a sustained attention driving task. PMID:26180329

  5. Analysis and Implementation of Efficient BLDC Motor Drive with Different Converter Systems

    Angeline Jayachandran*1,; Mrs. G.R.P Lakshmi2

    2014-01-01

    This Paper deals with analysis of efficient BLDC motor drive with various converter systems. Performance of the drive system is compared based on THD and PF at the AC mains with the following converter topology: Conventional DC-DC converter, SEPIC and CSC converter. The complete drive system is designed and modeled in MATLAB/Simulink environment for speed control over a wide range.

  6. Superluminal warp drive

    In this Letter we consider a warp drive spacetime resulting from that suggested by Alcubierre when the spaceship can only travel faster than light. Restricting to the two dimensions that retains most of the physics, we derive the thermodynamic properties of the warp drive and show that the temperature of the spaceship rises up as its apparent velocity increases. We also find that the warp drive spacetime can be exhibited in a manifestly cosmological form

  7. On state estimation in electric drives

    Leon, A.E., E-mail: aleon@ymail.co [Instituto de Investigaciones en Ingenieria Electrica (IIIE) ' Alfredo Desages' (UNS-CONICET), Departamento de Ingenieria Electrica y de Computadoras, Universidad Nacional del Sur - UNS, 1253 Alem Avenue, P.O. 8000, Bahia Blanca (Argentina); Solsona, J.A., E-mail: jsolsona@uns.edu.a [Instituto de Investigaciones en Ingenieria Electrica (IIIE) ' Alfredo Desages' (UNS-CONICET), Departamento de Ingenieria Electrica y de Computadoras, Universidad Nacional del Sur - UNS, 1253 Alem Avenue, P.O. 8000, Bahia Blanca (Argentina)

    2010-03-15

    This paper deals with state estimation in electric drives. On one hand a nonlinear observer is designed, whereas on the other hand the speed state is estimated by using the dirty derivative from the position measured. The dirty derivative is an approximate version of the perfect derivative which introduces an estimation error few times analyzed in drive applications. For this reason, our proposal in this work consists in illustrating several aspects on the performance of the dirty derivator in presence of both model uncertainties and noisy measurements. To this end, a case study is introduced. The case study considers rotor speed estimation in a permanent magnet stepper motor, by assuming that rotor position and electrical variables are measured. In addition, this paper presents comments about the connection between dirty derivators and observers, and advantages and disadvantages of both techniques are also remarked.

  8. On state estimation in electric drives

    This paper deals with state estimation in electric drives. On one hand a nonlinear observer is designed, whereas on the other hand the speed state is estimated by using the dirty derivative from the position measured. The dirty derivative is an approximate version of the perfect derivative which introduces an estimation error few times analyzed in drive applications. For this reason, our proposal in this work consists in illustrating several aspects on the performance of the dirty derivator in presence of both model uncertainties and noisy measurements. To this end, a case study is introduced. The case study considers rotor speed estimation in a permanent magnet stepper motor, by assuming that rotor position and electrical variables are measured. In addition, this paper presents comments about the connection between dirty derivators and observers, and advantages and disadvantages of both techniques are also remarked.

  9. Universal Drive Train Facility

    Federal Laboratory Consortium — This vehicle drive train research facility is capable of evaluating helicopter and ground vehicle power transmission technologies in a system level environment. The...

  10. Stator insulation systems for medium voltage PWM drives fed motors

    Gao, G.; Chen, W. [TECO-Westinghouse Motor Co., Round Rock, TX (United States)

    2005-07-01

    Adjustable speed drives (ASD) are commonly used in power electronics and control systems. It is estimated that more than 15 per cent of medium voltage motors are currently fed by such drives worldwide. A research project was conducted to examine the influence of medium voltage pulse width modulated (PWM) ASD on motor stator insulation systems. The findings, based on accelerated laboratory tests, have helped designers to improve the capabilities of the insulation system used for ASD-fed motors. Repetitive, high magnitude voltage spikes with fast rise time create significant stress on insulation systems. Gradual deterioration and premature failure of the motor insulation can result from surge voltages which generate surface discharges between phase windings/end windings, or partial discharges between stator turns. However, there is no industrial standard to evaluate motor insulation life under ASD-cable-motor conditions. Several material manufacturers have developed their own version of corona resistant material. However, the insulation life of ASD-fed motors does not depend solely on the raw materials. Rather, it depends on the complete insulation system, including the stator manufacturing process. In order to address this problem, TECO-Westinghouse Motor Company has developed special design criteria and manufacturing practices in order to reduce winding insulation temperature and to compensate for the additional heat generated by high frequency contents in the PWM voltage waveform. A patent pending new cooling system should reduce winding temperature by 15 to 20 degrees C. This paper presented design considerations for turn insulation, groundwall insulation, and a voltage stress grading system. A new thermal class H insulation system was also described. 6 refs., 2 tabs., 5 figs.

  11. Distributed control of electric drives via Ehernet

    Samaranayake, Lilantha

    2003-01-01

    This report presents the work carried out aiming towardsdistributed control of electric drives through a networkcommunication medium with temporal constraints, i.e, Ethernet.A general analysis on time delayed systems is carried out,using state space representation of systems in the discretetime domain. The effect of input time delays is identified andis used in the preceding controller designs. The main hardwareapplication focused in this study is a Brushless DC servomotor, whose speed contro...

  12. Vector controlled induction motor drive systems

    Bharadwaj, Aravind S.

    1993-01-01

    Over the years, dc motors have been widely used for variable speed drives for numerous industrial applications despite the fact that ac machines are robust, less expensive, and have low inertia rotors. The main disadvantage of the ac machines is the complexity in control and the cost of the related circuitry. With the advent of vector control, ac machines have overcome this disadvantage and are being employed in different applications where dc motors were traditionally used. The d-q modeling,...

  13. Drive Cycle Optimisation for Pollution Reduction

    Mostafa, Alghadhi; Andrew, Ball; Laszlo, Kollar; Rakesh, Mishra; Taimoor, Asim

    2015-01-01

    Green house gas emissions have abraded environmental quality for human existence. Automobile exhaust is a significant contributor globally to green house gases, among other contributors. This research investigates how vehicle fuel consumption can be tabulated from laboratory tests and road tests. The laboratory tests are used to establish mathematical relationships to predict fuel consumption as a function of such drive-cycle parameters as vehicle speed,acceleration and throttle position. The...

  14. Drive Cycle Optimisation for Pollution Reduction

    Alghadi, Mostafa; Ball, Andrew; Mishra, Rakesh; Asim, Taimoor

    2015-01-01

    Green house gas emissions have abraded environmental quality for human existence. Automobile exhaust is a significant contributor globally to green house gases, among other contributors. This research investigates how vehicle fuel consumption can be tabulated from laboratory tests and road tests. The laboratory tests are used to establish mathematical relationships to predict fuel consumption as a function of such drive-cycle parameters as vehicle speed, acceleration and throttle position. Th...

  15. Control of Adjustable Compliant Actuators

    Berno J.E. Misgeld

    2014-05-01

    Full Text Available Adjustable compliance or variable stiffness actuators comprise an additional element to elastically decouple the actuator from the load and are increasingly applied to human-centered robotic systems. The advantages of such actuators are of paramount importance in rehabilitation robotics, where requirements demand safe interaction between the therapy system and the patient. Compliant actuator systems enable the minimization of large contact forces arising, for example, from muscular spasticity and have the ability to periodically store and release energy in cyclic movements. In order to overcome the loss of bandwidth introduced by the elastic element and to guarantee a higher range in force/torque generation, new actuator designs consider variable or nonlinear stiffness elements, respectively. These components cannot only be adapted to the walking speed or the patient condition, but also entail additional challenges for feedback control. This paper introduces a novel design method for an impedance-based controller that fulfills the control objectives and compares the performance and robustness to a classical cascaded control approach. The new procedure is developed using a non-standard positive-real Η2 controller design and is applied to a loop-shaping approach. Robust norm optimal controllers are designed with regard to the passivity of the actuator load-impedance transfer function and the servo control problem. Classical cascaded and positive-real Η2 controller designs are validated and compared in simulations and in a test bench using a passive elastic element of varying stiffness.

  16. Exploration adjustment by ant colonies.

    Doran, Carolina; Stumpe, Martin C; Sendova-Franks, Ana; Franks, Nigel R

    2016-01-01

    How do animals in groups organize their work? Division of labour, i.e. the process by which individuals within a group choose which tasks to perform, has been extensively studied in social insects. Variability among individuals within a colony seems to underpin both the decision over which tasks to perform and the amount of effort to invest in a task. Studies have focused mainly on discrete tasks, i.e. tasks with a recognizable end. Here, we study the distribution of effort in nest seeking, in the absence of new nest sites. Hence, this task is open-ended and individuals have to decide when to stop searching, even though the task has not been completed. We show that collective search effort declines when colonies inhabit better homes, as a consequence of a reduction in the number of bouts (exploratory events). Furthermore, we show an increase in bout exploration time and a decrease in bout instantaneous speed for colonies inhabiting better homes. The effect of treatment on bout effort is very small; however, we suggest that the organization of work performed within nest searching is achieved both by a process of self-selection of the most hard-working ants and individual effort adjustment. PMID:26909180

  17. Credit Valuation Adjustment

    Hoffman, Frederick

    2011-01-01

    Credit risk has become a topical issue since the 2007 Credit Crisis, particularly for its impact on the valuation of OTC derivatives. This becomes critical when the credit risk of entities involved in a contract either as underlying or counterparty become highly correlated as is the case during macroeconomic shocks. It impacts the valuation of such contracts through an additional term, the credit valuation adjustment (CVA). This can become large with such correlation. This thesis outlines the...

  18. Adjustable Autonomy Testbed

    Malin, Jane T.; Schrenkenghost, Debra K.

    2001-01-01

    The Adjustable Autonomy Testbed (AAT) is a simulation-based testbed located in the Intelligent Systems Laboratory in the Automation, Robotics and Simulation Division at NASA Johnson Space Center. The purpose of the testbed is to support evaluation and validation of prototypes of adjustable autonomous agent software for control and fault management for complex systems. The AA T project has developed prototype adjustable autonomous agent software and human interfaces for cooperative fault management. This software builds on current autonomous agent technology by altering the architecture, components and interfaces for effective teamwork between autonomous systems and human experts. Autonomous agents include a planner, flexible executive, low level control and deductive model-based fault isolation. Adjustable autonomy is intended to increase the flexibility and effectiveness of fault management with an autonomous system. The test domain for this work is control of advanced life support systems for habitats for planetary exploration. The CONFIG hybrid discrete event simulation environment provides flexible and dynamically reconfigurable models of the behavior of components and fluids in the life support systems. Both discrete event and continuous (discrete time) simulation are supported, and flows and pressures are computed globally. This provides fast dynamic simulations of interacting hardware systems in closed loops that can be reconfigured during operations scenarios, producing complex cascading effects of operations and failures. Current object-oriented model libraries support modeling of fluid systems, and models have been developed of physico-chemical and biological subsystems for processing advanced life support gases. In FY01, water recovery system models will be developed.

  19. Physicians' adjustment to retirement.

    Virshup, B; Coombs, R H

    1993-01-01

    We address the questions, How do physicians adjust to and enjoy their retirement? What factors contribute to the well-being of retired physicians? A 60-item questionnaire mailed to 238 retired physicians in Los Angeles County with a 41.6% response rate assessed health, standard of living, relationships, activities, emotional difficulties, and general enjoyment. Health often improved after retirement, as did relationships with spouses and children. Standard of living was comfortable or better ...

  20. A speed auto-adaptable system for high speed inspection of rail-track defects

    Ge, Jia; Luo, Yunhan; Zhang, Jun; Guo, Long; Sun, Liang; Chen, Zhe

    2012-11-01

    High quality images play a key role in inspecting surface defect of rail track. However, image distortion is frequently occurred in traditional detection systems in which exposure frequency of camera are fixed as constant. The system studied in this paper improves traditional systems by combining a speed auto-adaptable (SAA) system, to adjust proper exposure frequency and uniform image quality all the time according to vehicle riding speed. The system mainly consists of a high-speed external controlled camera, a rotary encoder and a signal processing card, with this system, performance in avoiding image distortion both in laboratory test and practical application can be achieved with minimum detection precision of 0.2 mm at relative low speed and theoretically maximum detection speed of approximate 489 km/h.

  1. Determination of the swing technique characteristics and performance outcome relationship in golf driving for low handicap female golfers.

    Brown, Susan J; Nevill, Alan M; Monk, Stuart A; Otto, Steve R; Selbie, W Scott; Wallace, Eric S

    2011-11-01

    Previous studies on the kinematics of the golf swing have mainly focused on group analysis of male golfers of a wide ability range. In the present study, we investigated gross body kinematics using a novel method of analysis for golf research for a group of low handicap female golfers to provide an understanding of their swing mechanics in relation to performance. Data were collected for the drive swings of 16 golfers using a 12-camera three-dimensional motion capture system and a stereoscopic launch monitor. Analysis of covariance identified three covariates (increased pelvis-thorax differential at the top of the backswing, increased pelvis translation during the backswing, and a decrease in absolute backswing time) as determinants of the variance in clubhead speed (adjusted r (2) = 0.965, P < 0.05). A significant correlation was found between left-hand grip strength and clubhead speed (r = 0.54, P < 0.05) and between handicap and clubhead speed (r = -0.612, P < 0.05). Flexibility measures showed some correlation with clubhead speed; both sitting flexibility tests gave positive correlations (clockwise: r = 0.522, P < 0.05; counterclockwise: r = 0.711, P < 0.01). The results suggest that there is no common driver swing technique for optimal performance in low handicap female golfers, and therefore consideration should be given to individual swing characteristics in future studies. PMID:21988676

  2. Variable frequency drives : energy efficiency guide

    NONE

    2009-07-01

    This paper presented a guide on variable frequency drive (VFD) technology that was developed to provide a better understanding of VFDs and to facilitate their selection, application, and operation. The guide refers to drives as electronic VFDs. It does not cover variable speed drives (VSDs) that have mechanical or hydraulic controls. The main application for the guide is for off-the-shelf, low voltage VFDs used in combination with commercially available alternating current (ac), polyphase, induction motors in the factional to 500 horsepower range that are 600 V or less and have insulated gate bipolar transistors (IGBT) with pulse width modulation. The guide does not address engineered products for special and large motor applications.

  3. Piezoelectric drive circuit

    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.

  4. Fundamentals of electrical drives

    Veltman, André; De Doncker, Rik W

    2007-01-01

    Provides a comprehensive introduction to various aspects of electrical drive systems. This volume provides a presentation of dynamic generic models that cover all major electrical machine types and modulation/control components of a drive as well as dynamic and steady state analysis of transformers and electrical machines.

  5. Electric Vehicle - Economical driving

    Jensen, VCE, Steen V.; Schøn, Henriette

    1999-01-01

    How do you reduce the energy-wast when driving and loading EV's - or rather: How do I get more km/l out of an EV......How do you reduce the energy-wast when driving and loading EV's - or rather: How do I get more km/l out of an EV...

  6. Adjustment Criterion and Algorithm in Adjustment Model with Uncertain

    SONG Yingchun

    2015-02-01

    Full Text Available Uncertainty often exists in the process of obtaining measurement data, which affects the reliability of parameter estimation. This paper establishes a new adjustment model in which uncertainty is incorporated into the function model as a parameter. A new adjustment criterion and its iterative algorithm are given based on uncertainty propagation law in the residual error, in which the maximum possible uncertainty is minimized. This paper also analyzes, with examples, the different adjustment criteria and features of optimal solutions about the least-squares adjustment, the uncertainty adjustment and total least-squares adjustment. Existing error theory is extended with new observational data processing method about uncertainty.

  7. Evolutionary algorithm for vehicle driving cycle generation.

    Perhinschi, Mario G; Marlowe, Christopher; Tamayo, Sergio; Tu, Jun; Wayne, W Scott

    2011-09-01

    Modeling transit bus emissions and fuel economy requires a large amount of experimental data over wide ranges of operational conditions. Chassis dynamometer tests are typically performed using representative driving cycles defined based on vehicle instantaneous speed as sequences of "microtrips", which are intervals between consecutive vehicle stops. Overall significant parameters of the driving cycle, such as average speed, stops per mile, kinetic intensity, and others, are used as independent variables in the modeling process. Performing tests at all the necessary combinations of parameters is expensive and time consuming. In this paper, a methodology is proposed for building driving cycles at prescribed independent variable values using experimental data through the concatenation of "microtrips" isolated from a limited number of standard chassis dynamometer test cycles. The selection of the adequate "microtrips" is achieved through a customized evolutionary algorithm. The genetic representation uses microtrip definitions as genes. Specific mutation, crossover, and karyotype alteration operators have been defined. The Roulette-Wheel selection technique with elitist strategy drives the optimization process, which consists of minimizing the errors to desired overall cycle parameters. This utility is part of the Integrated Bus Information System developed at West Virginia University. PMID:22010377

  8. SYSTEMS FOR THE ADJUSTMENT OF THE MAIN KINEMATIC CHAIN OF THE VERTICAL TURNING LATHES

    Dan PRODAN

    2011-07-01

    Full Text Available This paperwork presents some systems for the adjustment of the main kinematic chains of theVertical Turning Lathes that have been used within the last 20 years. There are presented adjustment systemsused when having the machine equipped with older type motors, with only one speed, and also modern systemsfor which A.C. motors with the speed adjustable by frequency variation are needed. It insists on the presentrole of the “gearboxes” as torque multipliers and not as speed reducer.

  9. Electric drive motors for industrial robots

    Fichtner, K.

    1985-04-01

    In robotized industrial plants it is possible to use electric motors in the technological process and also for control, assembly, transport, testing, and measurements. Particularly suitable for these applications are permanent-magnet d.c. motors. A new special series was developed for industrial robots with hinge joints in kinematic pairs. The complete drive includes thyristors or transistor controls with regulators and, if necessary, a line transformer as well as a servomotor with tachometer and odometer for speed, current, and position control. The drive is coupled to a robot tong through mechanical torque and force converters. In addition to a 0 to 4000 rpm speed regulation, without wobble at low speeds, and a high torque-to-weight ratio for repetitive short-time heavy duty, these low-inertia motors develop high starting and accelerating torques over the entire speed range. They operate from a 1 to O 220 V a.c. line through a rectifier. The motors are totally enclosed, or of open construction for better ventilation. Their windings have class F insulation for operation at ambient temperatures up to 40 C.

  10. Low Speed Energy Conversion from Marine Currents

    Thomas, Karin

    2007-01-01

    The focus of this thesis is research on the performance of very low speed direct drive permanent magnet generators for energy conversion from marine and tidal currents. Various aspects involved in the design of these generators and their electromagnetic modelling using the finite element simulations are presented. For a detailed study, a 5 kW prototype generator has been designed and constructed based on finite element based simulations. Several experiments were conducted on the prototype gen...

  11. Jordan Adjusted Human Development

    Ababsa, Myriam

    2014-01-01

    Jordan Human Development Index (HDI) and Adjusted Human Development Index (IHDI) In 1990, the United Nations Development Programme designed a Human Development Index composed of life expectancy at birth, level of education and gross domestic product (GDP) per capita. In 2011, the UNDP ranked Jordan 95th out of 187 countries with a human development index of 0.698, up from 0.591 in 1990, making it the leading medium-range country for human development (fig. VIII.1). In 2010, the inequality adj...

  12. The Natario Warp Drive using Lorentz Boosts according to the Harold White Spacetime Metric potential $\\theta$

    Loup, Fernando

    2013-01-01

    Warp Drives are solutions of the Einstein Field Equations that allows superluminal travel within the framework of General Relativity.There are at the present moment two known solutions: The Alcubierre warp drive discovered in $1994$ and the Natario warp drive discovered in $2001$.The warp drive seems to be very attractive because allows interstellar space travel at arbitrarily large speeds avoiding the time dilatation and mass increase paradoxes of Special Relativity. However it suffers from ...

  13. Development of a KT driving cycle for UMT PHEV powertrain

    Atiq, W. H.; Haezah, M. N.; Norbakyah, J. S.; Salisa, A. R.

    2015-12-01

    Driving cycles were identified as one of the core sources that contribute to develop the powertrain for vehicle. Plug-in hybrid electric vehicles (PHEVs) are the future transport for next generation. Compared to conventional internal combustion engine vehicle, hybrid and electric vehicle can improve fuel economy and reduce green house gases. This paper describes a development of Kuala Terengganu driving cycle for Universiti Malaysia Terengganu PHEV. Car speed-time data along the two selected fixed route is obtained by using on-board technique which is Global Positioning System, GPS. The developed driving cycle contains a 1050s speed time series, with a distance of 2.17 km, and an average and a maximum speed of 20.67 km/h and 61.47 km/h, respectively. The results obtained from this analysis are within reasonable range and satisfactory.

  14. Comparison of drive systems for pulsed synchronous machines: an overview

    Magnetically confined plasma fusion experiments require large pulses of energy to be delivered into coil systems. One of the most effective methods of generating these high energy pulses is to convert stored inertial energy into electrical energy. Large synchronous generators of both the vertical and horizontal shaft type have been successfully used for this purpose. As the pulsed energy is delivered to the load, the inertial energy of the rotor of the machine is changed into electrical energy, causing the rotor to slow down. A drive system is required to accelerate the generator from standstill to the maximum operating speed and between load pulses from a reduced operating speed to the maximum speed. There are several types of drive systems that can be used for this application. An overview of six candidate drive systems is presented and comparisons of cost, performance, efficiency, and line effects for these systems are described

  15. Comparison of drive systems for pulsed synchronous machines - an overview

    Magnetically confined plasma fusion experiments require large pulses of energy to be delivered into coil systems. One of the most effective methods of generating these high energy pulses is to convert stored inertial energy into electrical energy. Large synchronous generators of both the vertical and horizontal shaft type have been successfully used for this purpose. As the pulsed energy is delivered to the load, the inertial energy of the rotor of the machine is changed into electrical energy, causing the rotor to slow down. A drive system is required to accelerate the generator from standstill to the maximum operating speed and between load pulses from a reduced operating speed to the maximum speed. There are several types of drive systems that can be used for this application. An overview of six candidate drive systems is presented and comparisons of cost, performance, efficiency and line effects for these systems are described

  16. Fast wave current drive

    Goree, J.; Ono, M.; Colestock, P.; Horton, R.; McNeill, D.; Park, H.

    1985-07-01

    Fast wave current drive is demonstrated in the Princeton ACT-I toroidal device. The fast Alfven wave, in the range of high ion-cyclotron harmonics, produced 40 A of current from 1 kW of rf power coupled into the plasma by fast wave loop antenna. This wave excites a steady current by damping on the energetic tail of the electron distribution function in the same way as lower-hybrid current drive, except that fast wave current drive is appropriate for higher plasma densities.

  17. Continuously adjustable Pulfrich spectacles

    Jacobs, Ken; Karpf, Ron

    2011-03-01

    A number of Pulfrich 3-D movies and TV shows have been produced, but the standard implementation has inherent drawbacks. The movie and TV industries have correctly concluded that the standard Pulfrich 3-D implementation is not a useful 3-D technique. Continuously Adjustable Pulfrich Spectacles (CAPS) is a new implementation of the Pulfrich effect that allows any scene containing movement in a standard 2-D movie, which are most scenes, to be optionally viewed in 3-D using inexpensive viewing specs. Recent scientific results in the fields of human perception, optoelectronics, video compression and video format conversion are translated into a new implementation of Pulfrich 3- D. CAPS uses these results to continuously adjust to the movie so that the viewing spectacles always conform to the optical density that optimizes the Pulfrich stereoscopic illusion. CAPS instantly provides 3-D immersion to any moving scene in any 2-D movie. Without the glasses, the movie will appear as a normal 2-D image. CAPS work on any viewing device, and with any distribution medium. CAPS is appropriate for viewing Internet streamed movies in 3-D.

  18. Driving When You Have Cataracts

    ... when they want. I Driving is a complex skill. Our ability to drive safely can be challenged by changes in our ... drive with you to see how well you drive with your cataract. I The ... to improve your driving skills. Improving your skills could help keep you and ...

  19. [Smoking while driving and its consequences on road safety].

    Mangiaracina, G; Palumbo, L

    2007-01-01

    The study was focused on the risk assessment of distraction of smoking habits while driving vehicles. We have compared the results with the data about driving distraction using mobile phone without voice devices. We video-recorded 10 smokers, 4 male and 6 female, smoking while driving a car The average of measured driving distraction of smokers is about 12 seconds. It means to cover a distance of 160 metres with a speed of 50 Km/h. Comparing to the use of mobile phone, the data of driving distraction show a duration of 10.6 seconds, that means to cover a distance of 150 metres at the speed of 50 Km/h. This result suggest that cigarette smoking produces a remarkable risk for road safety, more than the mobile phone use. In addiction to the conditions that produce a considerable driving distraction of smokers, we underline a demonstrated shortage of oxygen, the presence of carbon monoxide and hight concentration offine particulate in the air breathed inside the vehicle. We also consider another aspect related to smoking habits while driving vehicles: the environmental damage. In fact throwing cigarette outside, while the vehicle is moving, is the prevalent reason of setting fire to the edge of the road. This study proposes to make changes in the laws and regulation on road safety in order to fine smokers behaviour during vehicle driving. Furthermore it seems necessary to promote public information about those risks among people. PMID:17658112

  20. Neural network based PWM AC chopper fed induction motor drive

    Venkatesan Jamuna

    2009-01-01

    Full Text Available In this paper, a new Simulink model for a neural network controlled PWM AC chopper fed single phase induction motor is proposed. Closed loop speed control is achieved using a neural network controller. To maintain a constant fluid flow with a variation in pressure head, drives like fan and pump are operated with closed loop speed control. The need to improve the quality and reliability of the drive circuit has increased because of the growing demand for improving the performance of motor drives. With the increased availability of MOSFET's and IGBT's, PWM converters can be used efficiently in low and medium power applications. From the simulation studies, it is seen that the PWM AC chopper has a better harmonic spectrum and lesser copper loss than the Phase controlled AC chopper. It is observed that the drive system with the proposed model produces better dynamic performance, reduced overshoot and fast transient response. .

  1. PMBLDC motor drive with power factor correction controller

    George, G.J.; Ramachandran, Rakesh; Arun, N.

    2012-01-01

    This paper presents a boost converter configuration, control scheme and design of single phase power factor controller for permanent magnet brushless DC motor (PMBLDCM) drive. PMBLDC motors are the latest choice of researchers, due to the high efficiency, silent operation, compact size, high...... reliability, and low maintenance requirements. The proposed Power Factor Controller topology improves power quality by improving performance of PMBLDCM drive, such as reduction of AC main current harmonics, near unity power factor. PFC converter forces the drive to draw sinusoidal supply current in phase with...... supply voltage. It uses a boost converter to obtain unity power factor with improved performance. The system includes a speed controller for PMBLDC drive and a voltage controller for boost converter.. The voltage or speed controllers can be realized using proportional integral (PI) controller...

  2. Development of a drive system for a sequential space camera

    Sharpsteen, J. T.; Solheim, C. D.; Stoap, L. J.

    1976-01-01

    An electronically commutated dc motor is reported for driving the camera claw and magazine, and a stepper motor is described for driving the shutter with the two motors synchronized electrically. Subsequent tests on the breadboard positively proved the concept, but further development beyond this study should be done. The breadboard testing also established that the electronically commutated motor can control speed over a wide dynamic range, and has a high torque capability for accelerating loads. This performance suggested the possibility of eliminating the clutch from the system while retaining all of the other mechanical features of the DAC, if the requirement for independent shutter speeds and frame rates can be removed. Therefore, as a final step in the study, the breadboard shutter and shutter drive were returned to the original DAC configuration, while retaining the brushless dc motor drive.

  3. A larger motor/converter combination for higher efficiency drives

    Tavner, P.J. [Durham Univ., School of Engineering, Durham (United Kingdom); Jagiela, M. [Technical Univ. of Opole (Poland); Ingleton, C. [Durham Univ. (United Kingdom)

    2005-07-01

    The brushless doubly fed machine (BDFM) has been proposed for many years as a variable speed drive machine, where the converter does not need to be of equal rating to the motor. The advent of modern, compact voltage-fed PWM converters with flux vector control suggests that such converters could be combined with BDFM technology to achieve a larger rating integrated drive than has been possible with current integrated induction motor/converters. This paper describes a prototype integrated BDFM motor/converter of 4 and 8 pole technology rated at 11 kW implemented from proprietary components but using an advanced BDFM rotor design. Simulations have predicted its performance and tests are presented to characterise the potential of the drive. The paper shows the speed range possible from the drive and the limitations to its performance from power factor and the parameters of the machine. (orig.)

  4. Closed-loop control of respiratory drive using pressure-support ventilation: target drive ventilation.

    Spahija, Jadranka; Beck, Jennifer; de Marchie, Michel; Comtois, Alain; Sinderby, Christer

    2005-05-01

    By using diaphragm electrical activity (multiple-array esophageal electrode) as an index of respiratory drive, and allowing such activity above or below a preset target range to indicate an increased or reduced demand for ventilatory assistance (target drive ventilation), we evaluated whether the level of pressure-support ventilation can be automatically adjusted in response to exercise-induced changes in ventilatory demand. Eleven healthy individuals breathed through a circuit (18 cm H2O/L/second inspiratory resistance at 1 L/second flow; 0.5-1.0 L/second expiratory flow limitation) connected to a modified ventilator. Subjects breathed for 6-minute periods at rest and during 20 and 40 W of bicycle exercise, with and without target drive ventilation (the target was set to 60% of the increase in diaphragm electrical activity observed between rest and 20 W of unassisted exercise). With target drive ventilation during exercise, the level of pressure-support ventilation was automatically increased, reaching 13.3 +/- 4.0 and 20.3 +/- 2.8 cm H2O during 20- and 40-W exercise, respectively, whereas diaphragm electrical activity was reduced to a level within the target range. Both diaphragmatic pressure-time product and end-tidal CO2 were significantly reduced with target drive ventilation at the end of the 20- (p < 0.01) and 40-W (p < 0.001) exercise periods. Minute ventilation was not altered. These results demonstrate that target drive ventilation can automatically adjust pressure-support ventilation, maintaining a constant neural drive and compensating for changes in respiratory demand. PMID:15665323

  5. Characterization and Development of a KL Driving Cycle for PHERB Powertrain

    Salisa A. R.

    2016-01-01

    Full Text Available This paper presents the result that being obtained by development of Kenyir Lake driving cycle for a plug-in hybrid electric recreational boat (PHERB powertrain. This research is conducted by using on board measurement techniques; second-by-second driving speed data correlate to time is collected by using global positioning system of the boat along selected route. A combination of batteries and ultracapacitor pack are used for hybrid energy storage system in PHERB powertrain which is good for driving performance and energy efficiency. The developed driving cycle contains a 2294 s speed time series, with a distance of 8.19 km, and an average and a maximum speed of 12.85 km/h and 36.91 km/h, respectively. The characteristics of KL driving cycle are compared with existing standard drive cycles. The results obtained from this analysis are within reasonable range and satisfactory.

  6. The Analysis of McMonigal,Lewis and O'Byrne applied to the Natario Warp Drive Spacetime

    Loup, Fernando

    2011-01-01

    Warp Drives are solutions of the Einstein field equations that allows superluminal travel within the framework of General Relativity. There are at the present moment two known solutions: The Alcubierre warp drive discovered in $1994$ and the Natario warp drive discovered in $2001$. Recently McMonigal,Lewis and O'Byrne presented an important analysis for the Alcubierre warp drive:A warp drive ship at superluminal speeds in interstellar space would trap in the warp bubble all the particles and ...

  7. Space Drive Physics: Introduction and Next Steps

    Millis, M. G.

    Research toward the visionary goal of propellantless ``space drives'' is introduced, covering key physics issues and a listing of roughly 2-dozen approaches. The targeted advantage of a space drive is to circumvent the propellant constraints of rockets and the maneuvering limits of light sails by using the interactions between the spacecraft and its surrounding space for propulsion. At present, the scientific foundations from which to engineer a space drive have not been discovered and, objectively, might be impossible. Although no propulsion breakthroughs appear imminent, the subject has matured to where the relevant questions have been broached and are beginning to be answered. The critical make-break issues include; conservation of momentum, uncertain sources of reaction mass, and the net-external thrusting requirement. Note: space drives are not necessarily faster- than-light devices. Speed limits are a separate, unanswered issue. Relevant unsolved physics includes; the sources and mechanisms of inertial frames, coupling of gravitation and electromagnetism, and the nature of the quantum vacuum. The propulsion approaches span mostly stages 1 through 3 of the scientific method (defining the problem, collecting data, and articulating hypotheses), while some have matured to stage 4 (testing hypotheses). Nonviable approaches include `stiction drives,' `gyroscopic antigravity,' and `lifters.' No attempt is made to gauge the prospects of the remaining approaches. Instead, a list of next-step research questions is derived from the examination of these goals, unknowns, and concepts.

  8. Speed and income

    Fosgerau, Mogens

    2005-01-01

    The relationship between speed and income is established in a microeconomic model focusing on the trade-off between travel time and the risk of receiving a penalty for exceeding the speed limit. This is used to determine when a rational driver will choose to exceed the speed limit. The relationship...... between speed and income is found again in the empirical analysis of a cross-sectional dataset comprising 60,000 observations of car trips. This is used to perform regressions of speed on income, distance travelled, and a number of controls. The results are clearly statistically significant and indicate...... an average income elasticity of speed of 0.02; it is smaller at short distances and about twice as large at the longest distance investigated of 200 km....

  9. The Design of Fiscal Adjustments

    Alesina, Alberto Francesco; Ardagna, Silvia

    2013-01-01

    This paper offers three results. First, in line with the previous literature, we confirm that fiscal adjustments based mostly on the spending side are less likely to be reversed. Second, spending based fiscal adjustments have caused smaller recessions than tax based fiscal adjustments. Finally, certain combinations of policies have made it possible for spending based fiscal adjustments to be associated with growth in the economy even on impact rather than with a recession. Thus, expansionary ...

  10. Dual drive; Doppelt angetrieben

    Wilms, Jan

    2011-09-15

    The Opel Ampera was designed as an everyday car with an alternative drive system. A hybrid concept comprising both an electric motor and a gasoline engine ensures long mileage, but there is still the problem of high purchase cost.

  11. Safe driving for teens

    ... for crashes. Drivers and passengers should use automobile safety features at all times. These include: seat belts, shoulder straps, and headrests. Only drive cars that have air bags, padded dashes, safety glass, ...

  12. Quantum effects in the Alcubierre warp drive spacetime

    Hiscock, William A.

    1997-01-01

    The expectation value of the stress-energy tensor of a free conformally invariant scalar field is computed in a two-dimensional reduction of the Alcubierre ``warp drive'' spacetime. The stress-energy is found to diverge if the apparent velocity of the spaceship exceeds the speed of light. If such behavior occurs in four dimensions, then it appears implausible that ``warp drive'' behavior in a spacetime could be engineered, even by an arbitrarily advanced civilization.

  13. Structural Flexibility of Large Direct Drive Generators for Wind Turbines

    Shrestha, G.

    2013-01-01

    The trend in wind energy is towards large offshore wind farms. This trend has led to the demand for high reliability and large single unit wind turbines. Different energy conversion topologies such as multiple stage geared generators, single stage geared generators and gearless (direct drive) generators have been coupled to the wind turbine in the last decades. Direct drive generators based on permanent magnet technology have a high efficiency, less components and lower speeds that can transl...

  14. Comparison of Static Characteristics between Unregulated and Regulated Electrical Drives

    Jukić Antolović, Jelena; Jerković Štil, Vedrana; Hederić, Željko

    2013-01-01

    In this paper, the difference between an unregulated and a regulated electrical drive in terms of power losses is analyzed. First, open loop scalar control, closed loop scalar control and speed estimated scalar control are explained. Then, static characteristics obtained by experimental measurements are analyzed and compared for different control principles. Finally, based on experimental results, it is proposed when and which drive is to be used.

  15. Advanced conduction angle control of permanent magnet brushless motor drives

    Gan, J.; Chan, CC; Jiang, JZ; Chau, KT

    1998-01-01

    A novel advanced conduction angle control scheme for permanent magnet brushless motor drives is presented in this paper. The originality of this scheme is to employ the transformer EMF in stator windings to counteract the rotational EMF by controlling the advanced conduction angle when the motor drive operates above the base speed. Hence the constant-power operation region can be extended considerably, even though the current regulator is in saturation. The attractive feature of the proposed ...

  16. Technical Document for Price Adjustment

    Zheng Tian; Mulugeta Kahsai; Randall Jackson

    2014-01-01

    This document presents the basis for the price adjustment mechanisms in a time series IO model. The essentials of the price adjustment and price change propagation algorithms are presented, along with a matrix permutation algorithm that facilitates the implementation of the price adjustment mechanism. The Matlab function is provided.

  17. 46 CFR 154.1864 - Vessel speed within speed reduction.

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Vessel speed within speed reduction. 154.1864 Section... Vessel speed within speed reduction. The master shall ensure that the speed of the vessel is not greater than the posted speed reduction....

  18. Drunk Driving Campaign

    Christoffersen, Mette Buhl; Vogel, Klara Elisa Pingel

    2014-01-01

    This project evaluates a communication product, consisting of three flush-ad posters against drunk driving. The target group of this campaign is young men in the ages 18-22 in the outskirts of Denmark. The project's scientific theoretical approach is phenomenology which will give insight in the target groups life situation, furthermore the social constructivist perspective is used to understand the target group's opinions in relation to product and subject drunk driving because of the interac...

  19. Drinking and driving

    2003-01-01

    Alcohol misuse generates many health and social problems at a cost that society is increasingly unwilling to sustain. One of the most tragic consequences of alcohol misuse is the result of drinking and driving. Each week, impaired drivers kill 40 Canadian men, women and children and injure 1250 others. The Canadian Medical Association (CMA), in its campaign against drinking and driving, has recommended that a condition of obtaining or renewing a driver's licence include the individual's writt...

  20. Engineering Autonomous Driving Software

    Berger, Christian; Rumpe, Bernhard

    2014-01-01

    A larger number of people with heterogeneous knowledge and skills running a project together needs an adaptable, target, and skill-specific engineering process. This especially holds for a project to develop a highly innovative, autonomously driving vehicle to participate in the 2007 DARPA Urban Challenge. In this contribution, we present essential elements of a software and systems engineering process to develop a so-called artificial intelligence capable of driving autonomously in complex u...