Speed Control of Multiphase Cage Induction Motors Incorporating Supply Sequence

Directory of Open Access Journals (Sweden)

Drozdowski Piotr

2014-12-01

Full Text Available The subject of this paper is the control possibility of the multiphase cage induction motors having number of phases greater than 3. These motors have additional properties for speed control that distinguish them from the standard 3 phase motors: operation at various sequences of supplying voltages due to the inverter control and possible operation with few open-circuited phases. For each supply sequence different no load speeds at the same frequency can be obtained. This feature extends the motor application for miscellaneous drive demands including vector or scalar control. This depends mainly on the type of the stator winding for a given number of phases, since the principle of motor operation is based on co-operation of higher harmonics of magnetic field. Examples of operation are presented for a 9-phase motor, though general approach has been discussed. This motor was fed by a voltage source inverter at field oriented control with forced currents. The mathematical model of the motor was reduced to the form incorporating all most important physical features and appropriate for the control law formulation. The operation was illustrated for various supply sequences for “healthy” motor and for the motor operating at one phase broken. The obtained results have shown that parasitic influence of harmonic fields interaction has negligible influence on motor operation with respect to the useful coupling for properly designed stator winding.

Non Linear, Time Variant Speed Control of a Single Phase Hybrid Switched Reluctance Motor

DEFF Research Database (Denmark)

Jakobsen, Uffe; Ahn, Jin Woo

2009-01-01

A high torque ripple in a given motor always presents a challenge for the speed control, since this ripple may lead to excessive actuation and ultimately may even lead to instability. The conventional solution is to low pass filter the measured speed, but this lowers dynamic control performance...

Versatile real-time interferometer phase-detection system using high-speed digital techniques

International Nuclear Information System (INIS)

Mendell, D.S.; Willett, G.W.

1977-01-01

This paper describes the basic design and philosophy of a versatile real-time interferometer phase-detection system to be used on the 2XIIB and TMX magnetic-fusion experiments at Lawrence Livermore Laboratory. This diagnostics system is a satellite to a host computer and uses high-speed emitter-coupled logic techniques to derive data on real-time phase relationships. The system's input signals can be derived from interferometer outputs over a wide range of reference frequencies. An LSI-11 microcomputer is the interface between the high-speed phase-detection logic, buffer memory, human interaction, and host computer. Phase data on a storage CRT is immediately displayed after each experimental fusion shot. An operator can interrogate this phase data more closely from an interactive control panel, and the host computer can be simultaneously examining the system's buffer memory or arming the system for the next shot

Speed Control Analysis of Brushless DC Motor Based on Maximum Amplitude DC Current Feedback

Directory of Open Access Journals (Sweden)

Hassan M.A.A.

2014-07-01

Full Text Available This paper describes an approach to develop accurate and simple current controlled modulation technique for brushless DC (BLDC motor drive. The approach is applied to control phase current based on generation of quasi-square wave current by using only one current controller for the three phases. Unlike the vector control method which is complicated to be implemented, this simple current modulation technique presents advantages such as phase currents are kept in balance and the current is controlled through only one dc signal which represent maximum amplitude value of trapezoidal current (Imax. This technique is performed with Proportional Integral (PI control algorithm and triangular carrier comparison method to generate Pulse Width Modulation (PWM signal. In addition, the PI speed controller is incorporated with the current controller to perform desirable speed operation of non-overshoot response. The performance and functionality of the BLDC motor driver are verified via simulation by using MATLAB/SIMULINK. The simulation results show the developed control system performs desirable speed operation of non-overshoot and good current waveforms.

An adaptive nonlinear internal-model control for the speed control of homopolar salient-pole BLDC motor

Science.gov (United States)

CheshmehBeigi, Hassan Moradi

2018-05-01

In this paper, a novel speed control method for Homopolar Brushless DC (HBLDC) motor based on the adaptive nonlinear internal-model control (ANIMC) is presented. Rotor position information is obtained online by the Hall-Effect sensors placed on the motor's shaft, and is used to calculate the accurate model and accurate inverse model of the HBLDC motor. The online inverse model of the motor is used in the controller structure. To suppress the reference ? error, the negative feedback of difference between the motor speed and its model output ? is applied in the proposed controller. An appropriate signal is the output of the controller, which drives the power switches to converge the motor speed to the constant desired speed. Simulations and experiments are carried out on a ? three-phase HBLDC motor. The proposed drive system operates well in the speed response and has good robustness with respect to the disturbances. To validate the theoretical analysis, several experimental results are discussed in this paper.

Critical Speed Control for a Fixed Blade Variable Speed Wind Turbine

Directory of Open Access Journals (Sweden)

Morgan Rossander

2017-10-01

Full Text Available A critical speed controller for avoiding a certain rotational speed is presented. The controller is useful for variable speed wind turbines with a natural frequency in the operating range. The controller has been simulated, implemented and tested on an open site 12 kW vertical axis wind turbine prototype. The controller is based on an adaptation of the optimum torque control. Two lookup tables and a simple state machine provide the control logic of the controller. The controller requires low computational resources, and no wind speed measurement is needed. The results suggest that the controller is a feasible method for critical speed control. The skipping behavior can be adjusted using only two parameters. While tested on a vertical axis wind turbine, it may be used on any variable speed turbine with the control of generator power.

Sound speed during the QCD phase transition

International Nuclear Information System (INIS)

Nagasawa, Michiyasu; Yokoyama, Jun'ichi

1998-01-01

The Jeans scale is estimated during the coexistence epoch of quark-gluon and hadron phases in the first-order QCD phase transition. It is shown that, contrary to previous claims, reduction of the sound speed is so little that the phase transition does not affect evolution of cosmological density fluctuations appreciably. (author)

DC motor speed control using fuzzy logic controller

Science.gov (United States)

Ismail, N. L.; Zakaria, K. A.; Nazar, N. S. Moh; Syaripuddin, M.; Mokhtar, A. S. N.; Thanakodi, S.

2018-02-01

The automatic control has played a vital role in the advance of engineering and science. Nowadays in industries, the control of direct current (DC) motor is a common practice thus the implementation of DC motor controller speed is important. The main purpose of motor speed control is to keep the rotation of the motor at the present speed and to drive a system at the demand speed. The main purpose of this project is to control speed of DC Series Wound Motor using Fuzzy Logic Controller (FLC). The expectation of this project is the Fuzzy Logic Controller will get the best performance compared to dc motor without controller in terms of settling time (Ts), rise time (Tr), peak time (Tp) and percent overshoot (%OS).

Instantaneous phase-shifting Fizeau interferometry with high-speed pixelated phase-mask camera

Science.gov (United States)

Yatagai, Toyohiko; Jackin, Boaz Jessie; Ono, Akira; Kiyohara, Kosuke; Noguchi, Masato; Yoshii, Minoru; Kiyohara, Motosuke; Niwa, Hayato; Ikuo, Kazuyuki; Onuma, Takashi

2015-08-01

A Fizeou interferometer with instantaneous phase-shifting ability using a Wollaston prism is designed. to measure dynamic phase change of objects, a high-speed video camera of 10-5s of shutter speed is used with a pixelated phase-mask of 1024 × 1024 elements. The light source used is a laser of wavelength 532 nm which is split into orthogonal polarization states by passing through a Wollaston prism. By adjusting the tilt of the reference surface it is possible to make the reference and object beam with orthogonal polarizations states to coincide and interfere. Then the pixelated phase-mask camera calculate the phase changes and hence the optical path length difference. Vibration of speakers and turbulence of air flow were successfully measured in 7,000 frames/sec.

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

DEFF Research Database (Denmark)

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...

Speed control at low wind speeds for a variable speed fixed pitch wind turbine

Energy Technology Data Exchange (ETDEWEB)

Rosmin, N.; Watson, S.J.; Tompson, M. [Loughborough Univ., Loughborough, Leicestershire (United Kingdom)

2010-03-09

The maximum power regulation below rated wind speed is regulated by changing the rotor/generator speed at large frequency range in a fixed pitch, variable speed, stall-regulated wind turbine. In order to capture the power at a maximum value the power coefficient is kept at maximum peak point by maintaining the tip speed ratio at its optimum value. The wind industry is moving from stall regulated fixed speed wind turbines to newer improved innovative versions with better reliability. While a stall regulated fixed pitch wind turbine is among the most cost-effective wind turbine on the market, its problems include noise, severe vibrations, high thrust loads and low power efficiency. Therefore, in order to improve such drawbacks, the rotation of the generator speed is made flexible where the rotation can be controlled in variable speed. This paper discussed the development of a simulation model which represented the behaviour of a stall regulated variable speed wind turbine at low wind speed control region by using the closed loop scalar control with adjustable speed drive. The paper provided a description of each sub-model in the wind turbine system and described the scalar control of the induction machine. It was concluded that by using a constant voltage/frequency ratio of the generator's stator side control, the generator speed could be regulated and the generator torque could be controlled to ensure the power coefficient could be maintained close to its maximum value. 38 refs., 1 tab., 10 figs.

Speed Sensorless vector control of parallel-connected three-phase two-motor single-inverter drive system

DEFF Research Database (Denmark)

Gunabalan, Ramachandiran; Sanjeevikumar, Padmanaban; Blaabjerg, Frede

2016-01-01

to noise and parameter uncertainty. The gain matrix is absent in the natural observer. The rotor speed is estimated from the load torque, stator current, and rotor flux. Under symmetrical load conditions, the difference in speed between two induction motors is reduced by considering the motor parameters......This paper presents the characteristic behavior of direct vector control of two induction motors with sensorless speed feedback having the same rating parameters, paralleled combination, and supplied from a single current-controlled pulse-width-modulated voltage-source inverter drive. Natural...... observer design technique is known for its simple construction, which estimates the speed and rotor fluxes. Load torque is estimated by load torque adaptation and the average rotor flux was maintained constant by rotor flux feedback control. The technique’s convergence rate is very fast and is robust...

Speed control of switched reluctance motors taking into account mutual inductances and magnetic saturation effects

International Nuclear Information System (INIS)

Alrifai, M.; Zribi, M.; Rayan, M.; Krishnan, R.

2010-01-01

This paper deals with the speed control of switched reluctance motor (SRM) drives taking into account the effects of the mutual inductances between two adjacent phases and the effects of the magnetic saturation of the core. To overcome the problems commonly associated with single-phase excitation, a nonlinear SRM model, which is suitable for two-phase excitation and which takes into account the effects of mutual inductances between two adjacent phases and the magnetic saturation effects, is considered in the design of the proposed controllers. A feedback linearization control scheme and a sliding mode control scheme are designed for this motor drive. The proposed controllers guarantee the convergence of the phase currents and the rotor speed of the motor to their desired values. Simulation results indicate that the proposed controllers work well and that they are robust to changes in the parameters of the system and to changes in the load torque.

Speed control of switched reluctance motors taking into account mutual inductances and magnetic saturation effects

Energy Technology Data Exchange (ETDEWEB)

Alrifai, M., E-mail: alrifm@eng.kuniv.edu.k [Electrical Engineering Department, College of Engineering and Petroleum, Kuwait University, P.O. Box 5969, Safat 13060 (Kuwait); Zribi, M.; Rayan, M. [Electrical Engineering Department, College of Engineering and Petroleum, Kuwait University, P.O. Box 5969, Safat 13060 (Kuwait); Krishnan, R. [Center for Rapid Transit Systems, Electrical and Computer Engineering Department, Virginia Tech University, 461 Durham Hall, Blacksburg, VA 24061-011 (United States)

2010-06-15

This paper deals with the speed control of switched reluctance motor (SRM) drives taking into account the effects of the mutual inductances between two adjacent phases and the effects of the magnetic saturation of the core. To overcome the problems commonly associated with single-phase excitation, a nonlinear SRM model, which is suitable for two-phase excitation and which takes into account the effects of mutual inductances between two adjacent phases and the magnetic saturation effects, is considered in the design of the proposed controllers. A feedback linearization control scheme and a sliding mode control scheme are designed for this motor drive. The proposed controllers guarantee the convergence of the phase currents and the rotor speed of the motor to their desired values. Simulation results indicate that the proposed controllers work well and that they are robust to changes in the parameters of the system and to changes in the load torque.

Speed control variable rate irrigation

Science.gov (United States)

Speed control variable rate irrigation (VRI) is used to address within field variability by controlling a moving sprinkler’s travel speed to vary the application depth. Changes in speed are commonly practiced over areas that slope, pond or where soil texture is predominantly different. Dynamic presc...

Plasma Control of Turbine Secondary Flows, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — We propose Phase I and II efforts that will focus on turbomachinery flow control. Specifically, the present work will investigate active control in a high speed...

Modeling and Speed Control of Induction Motor Drives Using Neural Networks

Directory of Open Access Journals (Sweden)

V. Jamuna

2010-08-01

Full Text Available Speed control of induction motor drives using neural networks is presented. The mathematical model of single phase induction motor is developed. A new simulink model for a neural network-controlled bidirectional chopper fed single phase induction motor is proposed. Under normal operation, the true drive parameters are real-time identified and they are converted into the controller parameters through multilayer forward computation by neural networks. Comparative study has been made between the conventional and neural network controllers. It is observed that the neural network controlled drive system has better dynamic performance, reduced overshoot and faster transient response than the conventional controlled system.

Real-time interferometer phase detection using an LSI-11 microcomputer and high-speed digital techniques

International Nuclear Information System (INIS)

Mendell, D.S.

1978-01-01

This paper describes the basic design and philosophy of a real-time, interferometer phase-detection system used on the 2XIIB and TMX magnetic-fusion experiments at the Lawrence Livermore Laboratory. This diagnostics system is now a satellite to a host computer and uses high-speed, emitter-coupled logic techniques to derive data on real-time phase relationships. The system's input signals can be derived from interferometer outputs over a wide range of reference frequencies. An LSI-11 microcomputer is the interface between the high-speed phase-detection logic, buffer memory, human interaction, and host computer. Phase data on a storage CRT is immediately displayed after each experimental fusion shot. An operator can interrogate this phase data more closely from an interactive control panel, while the host computer is simultaneously examining the system's buffer memory or arming the system for the next shot

Research on Control System of Three - phase Brushless DC Motor for Electric Vehicle

Science.gov (United States)

Wang, Zhiwei; Jin, Hai; Guo, Jie; Su, Jie; Wang, Miao

2017-12-01

In order to study the three-phase brushless motor control system of electric vehicle, Freescale9S12XS128 chip is used as the control core, and the power MOSFET is used as the inverter device. The software is compiled by Codewarrior software. The speed control link adopts open-loop control, and the control chip collects the external sensor signal voltage Change control PWM signal output control three-phase brushless DC motor speed. The whole system consists of Hall position detection module, current detection module, power drive module and voltage detection module. The basic functions of three-phase brushless DC motor drive control are realized.

Modeling, Simulation and Control of Matrix Convert for Variable Speed Wind Turbine System

Directory of Open Access Journals (Sweden)

M. Alizadeh Moghadam

2015-09-01

Full Text Available This paper presents modeling, simulation and control of matrix converter (MC for variable speed wind turbine (VSWT system including permanent magnet synchronous generator (PMSG. At a given wind velocity, the power available from a wind turbine is a function of its shaft speed. In order to track maximum power, the MC adjusts the PMSG shaft speed.The proposed control system allowing independent control maximum power point tracking (MPPT of generator side and regulate reactive power of grid side for the operation of the VSWT system. The MPPT is implemented by a new control system. This control system is based on control of zero d-axis current (ZDC. The ZDC control can be realized by transfer the three-phase stator current in the stationary reference frame into d-and q-axis components in the synchronous reference frame. Also this paper is presented, a novel control strategy to regulate the reactive power supplied by a variable speed wind energy conversion system. This control strategy is based on voltage oriented control (VOC. The simulation results based on Simulink/Matlab software show that the controllers can extract maximum power and regulate reactive power under varying wind velocities.

A two-phase control algorithm for gear-shifting in a novel multi-speed transmission for electric vehicles

Science.gov (United States)

Roozegar, M.; Angeles, J.

2018-05-01

In light of the current low energy-storage capacity of electric batteries, multi-speed transmissions (MSTs) are being considered for applications in electric vehicles (EVs), since MSTs decrease the energy consumption of the EV via gear-shifting. Nonetheless, swiftness and seamlessness are the major concerns in gear-shifting. This study focuses on developing a gear-shifting control scheme for a novel MST designed for EVs. The main advantages of the proposed MST are simplicity and modularity. Firstly, the dynamics model of the transmission is formulated. Then, a two-phase algorithm is proposed for shifting between each two gear ratios, which guarantees a smooth and swift shift. In other words, a separate control set is applied for shifting between each gear pair, which includes two independent PID controllers, tuned using trial-and-error and a genetic algorithm (GA), for the two steps of the algorithm and a switch. A supervisory controller is also employed to choose the proper PID gains, called PID gain-scheduling. Simulation results for various controllers and conditions are reported and compared, indicating that the proposed scheme is highly promising for a desired gear-shifting even in the presence of an unknown external disturbance.

Advanced nonlinear engine speed control systems

DEFF Research Database (Denmark)

Vesterholm, Thomas; Hendricks, Elbert

1994-01-01

Several subsidiary control problems have turned out to be important for improving driveability and fuel consumption in modern spark ignition (SI) engine cars. Among these are idle speed control and cruise control. In this paper the idle speed and cruise control problems will be treated as one......: accurately tracking of a desired engine speed in the presence of model uncertainties and severe load disturbances. This is accomplished by using advanced nonlinear control techniques such as input/output-linearization and sliding mode control. These techniques take advantage of a nonlinear model...... of the engine dynamics, a mean value engine model....

Optimal Speed Control for Cruising

DEFF Research Database (Denmark)

Blanke, M.

1994-01-01

With small profit margins in merchant shipping and more than eighty percent of sailing time being cross ocean voyages, speed control is crucial for vessel profitability......With small profit margins in merchant shipping and more than eighty percent of sailing time being cross ocean voyages, speed control is crucial for vessel profitability...

High-frequency, three-phase current controller implementation in an FPGA

Energy Technology Data Exchange (ETDEWEB)

Hartmann, M.; Round, S. D.; Kolar, J. W.

2008-07-01

Three phase rectifiers with switching frequencies of 500 kHz or more require high speed current controllers. At such high switching frequencies analog controllers as well as high speed digital signal processing (DSP) systems have limited performance. In this paper, two high speed current controller implementations using two different field-programmable gate arrays (FPGA) - one for switching frequencies up to 1 MHz and one for switching frequencies beyond 1 MHz - are presented to overcome this performance limitation. Starting with the digital system design all the blocks of the signal chain, containing analog-to-digital (A/D) interface, digital controller implementation using HW-multipliers and implementation of a novel high speed, high resolution pulse width modulation (PWM) are discussed and compared. Final measurements verify the performance of the controllers. (author)

Power-Quality-Oriented Optimization in Multiple Three-Phase Adjustable Speed Drives

DEFF Research Database (Denmark)

Yang, Yongheng; Davari, Pooya; Blaabjerg, Frede

2016-01-01

As an almost standardized configuration, Diode Rectifiers (DRs) and Silicon-Controlled Rectifiers (SCRs) are commonly employed as the front-end topology in three-phase Adjustable Speed Drive (ASD) systems. Features of this ASD configuration include: structural and control simplicity, small volume......, low cost, and high reliability during operation. Yet, DRs and SCRs bring harmonic distortions in the mains and thus lowering the overall efficiency. Power quality standards/rules are thus released. For multiple ASD systems, certain harmonics of the total grid current can be mitigated by phase......-shifting the currents drawn by SCR-fed drives, and thus it is much flexible to reduce the Total Harmonic Distortion (THD) level in such applications. However, the effectiveness of this harmonic mitigation scheme for multiple ASD systems depends on: a) the number of parallel drives, b) the power levels, and c...

Safety Impact of Average Speed Control in the UK

DEFF Research Database (Denmark)

Lahrmann, Harry Spaabæk; Brassøe, Bo; Johansen, Jonas Wibert

2016-01-01

of automatic speed control was point-based, but in recent years a potentially more effective alternative automatic speed control method has been introduced. This method is based upon records of drivers’ average travel speed over selected sections of the road and is normally called average speed control...... in the UK. The study demonstrates that the introduction of average speed control results in statistically significant and substantial reductions both in speed and in number of accidents. The evaluation indicates that average speed control has a higher safety effect than point-based automatic speed control....

An Analysis of Variable-Speed Wind Turbine Power-Control Methods with Fluctuating Wind Speed

Directory of Open Access Journals (Sweden)

Seung-Il Moon

2013-07-01

Full Text Available Variable-speed wind turbines (VSWTs typically use a maximum power-point tracking (MPPT method to optimize wind-energy acquisition. MPPT can be implemented by regulating the rotor speed or by adjusting the active power. The former, termed speed-control mode (SCM, employs a speed controller to regulate the rotor, while the latter, termed power-control mode (PCM, uses an active power controller to optimize the power. They are fundamentally equivalent; however, since they use a different controller at the outer control loop of the machine-side converter (MSC controller, the time dependence of the control system differs depending on whether SCM or PCM is used. We have compared and analyzed the power quality and the power coefficient when these two different control modes were used in fluctuating wind speeds through computer simulations. The contrast between the two methods was larger when the wind-speed fluctuations were greater. Furthermore, we found that SCM was preferable to PCM in terms of the power coefficient, but PCM was superior in terms of power quality and system stability.

High speed motion neutron radiography of two-phase flow

International Nuclear Information System (INIS)

Robinson, A.H.; Wang, S.L.

1983-01-01

Current research in the area of two-phase flow utilizes a wide variety of sensing devices, but some limitations exist on the information which can be obtained. Neutron radiography is a feasible alternative to ''see'' the two-phase flow. A system to perform neutron radiographic analysis of dynamic events which occur on the order of several milliseconds has been developed at Oregon State University. Two different methods have been used to radiograph the simulated two-phase flow. These are pulsed, or ''flash'' radiography, and high speed movie neutron radiography. The pulsed method serves as a ''snap-shot'' with an exposure time ranging from 10 to 20 milliseconds. In high speed movie radiography, a scintillator is used to convert neutrons into light which is enhanced by an optical intensifier and then photographed by a high speed camera. Both types of radiography utilize the pulsing capability of the OSU TRIGA reactor. The principle difficulty with this type of neutron radiography is the fogging of the image due to the large amount of scattering in the water. This difficulty can be overcome by using thin regions for the two-phase flow or using heavy water instead of light water. The results obtained in this paper demonstrate the feasibility of using neutron radiography to obtain data in two-phase flow situations. Both movies and flash radiographs have been obtained of air bubbles in water and boiling from a heater element. The neutron radiographs of the boiling element show both nucleate boiling and film boiling. (Auth.)

High-speed elevators controlled by inverters

Energy Technology Data Exchange (ETDEWEB)

Sakai, Yoshio; Takahashi, Hideaki; Nakamura, Kiyoshi; Kinoshita, Hiroshi

1988-10-25

The super-high-speed elevator with superiority to 300m/min of speed, requires both the large capacity power and wide range speed controls. Therefore, in order to materialize the smooth and quiet operation characteristics, by applying the inverter control, the low torque ripple control in the low frequency range and high frequency large capacity inverting for lowering the motor in noise are necessary with their being assured of reliability. To satisfy the above necessary items, together with the development of a sine wave pulse width and frequency modulation (PWM/PFM) control system, to more precisely enable the sine wave electric current control, and 3kHz switching power converter, using a 800A power transistor module, a supervoltage control circuit under the extraordinary condition was designed. As a result of commercializing a 360m/min super-high speed inverter elevator, the power source unit, due to the effect of high power factor, could be reduced by 30% in capacity and also the higher harmonic wave including ratio could be considerably lowered to the inferiority to 5%. 2 references, 7 figures, 1 table.

Performance analysis of variable speed multiphase induction motor with pole phase modulation

Directory of Open Access Journals (Sweden)

Liu Huijuan

2016-09-01

Full Text Available The pole phase modulation (PPM technique is an effective method to extend speed range and torque capabilities for an integrated starter and hybrid electric vehicles applications. In this paper, the five pole-phase combination types of a multiphase induction motor (IM with 36 stator slots and 36 stator conductors are presented and compared quantitatively by using the time-stepping finite element method (TS-FEM. The 36 stator conductors of the proposed multiphase IM are fed by a 36 leg inverter and the current phase angle and amplitude of each stator conductor can be controlled independently. This paper focuses on the winding connection, the PPM technique and the performance comparative analysis of each pole-phase combination types of the proposed multiphase IM. The flux distribution, air-gap flux density, output torque, core losses and efficiency of five pole-phase combination types have been investigated.

Grey Wolf based control for speed ripple reduction at low speed operation of PMSM drives.

Science.gov (United States)

Djerioui, Ali; Houari, Azeddine; Ait-Ahmed, Mourad; Benkhoris, Mohamed-Fouad; Chouder, Aissa; Machmoum, Mohamed

2018-03-01

Speed ripple at low speed-high torque operation of Permanent Magnet Synchronous Machine (PMSM) drives is considered as one of the major issues to be treated. The presented work proposes an efficient PMSM speed controller based on Grey Wolf (GW) algorithm to ensure a high-performance control for speed ripple reduction at low speed operation. The main idea of the proposed control algorithm is to propose a specific objective function in order to incorporate the advantage of fast optimization process of the GW optimizer. The role of GW optimizer is to find the optimal input controls that satisfy the speed tracking requirements. The synthesis methodology of the proposed control algorithm is detailed and the feasibility and performances of the proposed speed controller is confirmed by simulation and experimental results. The GW algorithm is a model-free controller and the parameters of its objective function are easy to be tuned. The GW controller is compared to PI one on real test bench. Then, the superiority of the first algorithm is highlighted. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Tickover speed controller for car engines

Energy Technology Data Exchange (ETDEWEB)

Hawk, R L

1980-05-22

In general, the tickover speed of a car engine is made sufficiently high, in order to permit an assumed maximum load to be taken from the engine at tickover. This setting of the tickover speed is usually done by stops in the fuel supply. Matching the actual load would lead to lower fuel consumption, without any danger of the engine stalling. The purpose of the invention is to provide a tickover speed controller, so that the tickover speed is adjusted by electronic control equipment, independently of the machine load. The fuel consumption on tickover is reduced and the emission of noxious substances is decreased. The electro-magnetic control of the throttle valve tickover setting is explained by extensive section drawings of the system. This process dispenses with the special tickover cams for a cold start.

Effect of Different Training Methods on Stride Parameters in Speed Maintenance Phase of 100-m Sprint Running.

Science.gov (United States)

Cetin, Emel; Hindistan, I Ethem; Ozkaya, Y Gul

2018-05-01

Cetin, E, Hindistan, IE, Ozkaya, YG. Effect of different training methods on stride parameters in speed maintenance phase of 100-m sprint running. J Strength Cond Res 32(5): 1263-1272, 2018-This study examined the effects of 2 different training methods relevant to sloping surface on stride parameters in speed maintenance phase of 100-m sprint running. Twenty recreationally active students were assigned into one of 3 groups: combined training (Com), horizontal training (H), and control (C) group. Com group performed uphill and downhill training on a sloping surface with an angle of 4°, whereas H group trained on a horizontal surface, 3 days a week for 8 weeks. Speed maintenance and deceleration phases were divided into distances with 10-m intervals, and running time (t), running velocity (RV), step frequency (SF), and step length (SL) were measured at preexercise, and postexercise period. After 8 weeks of training program, t was shortened by 3.97% in Com group, and 2.37% in H group. Running velocity also increased for totally 100 m of running distance by 4.13 and 2.35% in Com, and H groups, respectively. At the speed maintenance phase, although t and maximal RV (RVmax) found to be statistically unaltered during overall phase, t was found to be decreased, and RVmax was preceded by 10 m in distance in both training groups. Step length was increased at 60-70 m, and SF was decreased at 70-80 m in H group. Step length was increased with concomitant decrease in SF at 80-90 m in Com group. Both training groups maintained the RVmax with a great percentage at the speed maintenance phase. In conclusion, although both training methods resulted in an increase in running time and RV, Com training method was more prominently effective method in improving RV, and this improvement was originated from the positive changes in SL during the speed maintaining phase.

Engine control system having speed-based timing

Science.gov (United States)

Willi, Martin L [Dunlap, IL; Fiveland, Scott B [Metamora, IL; Montgomery, David T [Edelstein, IL; Gong, Weidong [Dunlap, IL

2012-02-14

A control system for an engine having a cylinder is disclosed having an engine valve movable to regulate a fluid flow of the cylinder and an actuator associated with the engine valve. The control system also has a controller in communication with the actuator. The controller is configured to receive a signal indicative of engine speed and compare the engine speed signal with a desired engine speed. The controller is also configured to selectively regulate the actuator to adjust a timing of the engine valve to control an amount of air/fuel mixture delivered to the cylinder based on the comparison.

Pitch Angle Control for Variable Speed Wind Turbines

DEFF Research Database (Denmark)

Chen, Zhe; Zhang, Jianzhong; Cheng, M

2008-01-01

Pitch angle control is the most common means for adjusting the aerodynamic torque of the wind turbine when wind speed is above rated speed and various controlling variables may be chosen, such as wind speed, generator speed and generator power. As conventional pitch control usually use PI...... controller, the mathematical model of the system should be known well. A fuzzy logic pitch angle controller is developed in this paper, in which it does not need well known about the system and the mean wind speed is used to compensate the non-linear sensitivity. The fuzzy logic control strategy may have...... the potential when the system contains strong non-linearity, such as wind turbulence is strong, or the control objectives include fatigue loads. The design of the fuzzy logic controller and the comparisons with conversional pitch angle control strategies with various controlling variables are carried out...

Variable speed control for Vertical Axis Wind Turbine

DEFF Research Database (Denmark)

Galinos, Christos; Larsen, Torben J.

A robust variable speed control for vertical axis wind turbine applications is implemented. It is a PI rotor speed controller based on an induction generator model operated at variable frequency. The generator dynamics are approximated by a first order differential equation with a prescribed slip....... In order to allow variability in the rotor speed an inverter is assumed which changes the nominal generator speed. Below rated power the optimum tip speed ratio is tracked, while above the power is constrained to rated. The wind speed which is needed in the control it is considered as a known signal...... the Inflow project. The investigation of the VAWT performance under different control parameters such as the PI gains has been performed by Christos Galinos. Deterministic and turbulent wind speed steps of 2 m/s from 6 m/s to 24 m/s and back to 12 m/s are applied. The controller gives smooth transient...

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

DEFF Research Database (Denmark)

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

2008-01-01

voltage-current model with PI compensator for low-speed operations. As speed increases, the observer switches gradually to a PI compensated closed-loop voltage model, which is solely used at high speeds. High-frequency rotating-voltage injection with a single D-module bandpass vector filter and a phase......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...

Wheel speed management control system for spacecraft

Science.gov (United States)

Goodzeit, Neil E. (Inventor); Linder, David M. (Inventor)

1991-01-01

A spacecraft attitude control system uses at least four reaction wheels. In order to minimize reaction wheel speed and therefore power, a wheel speed management system is provided. The management system monitors the wheel speeds and generates a wheel speed error vector. The error vector is integrated, and the error vector and its integral are combined to form a correction vector. The correction vector is summed with the attitude control torque command signals for driving the reaction wheels.

The speed of growth of the gamma phase comes prime in nickel based alloys

International Nuclear Information System (INIS)

Peretti, M.M; Ges, A.M; Versaci, R.A

2004-01-01

Nickel-based alloys have a high fraction in volume of precipitate phase. This precipitate phase provides the characteristics of high mechanical resistance to high temperatures and, therefore, a study of the growth of this phase can predict the behavior of the components in service. This work studies the speed of growth in the alloy INCONEL 713C at temperatures of 800 o C, 875 o C and 950 o C with different treatment times. The present phase in this alloy is Ni3(AlTi), with a very high fraction in volume. The follow-up on the growth of the phase was carried out using scanning and transmission electron microscopy techniques. The speed of growth presents modifications that increase and decrease as a function of time. These variations in speed are attributed to modifications in the size and morphology of the precipitate particles. The changes in size and morphology directly influence the interfacial energy that produces the change in the speed of growth (CW)

Differences of muscle co-contraction of the ankle joint between young and elderly adults during dynamic postural control at different speeds.

Science.gov (United States)

Iwamoto, Yoshitaka; Takahashi, Makoto; Shinkoda, Koichi

2017-08-02

Agonist and antagonist muscle co-contractions during motor tasks are greater in the elderly than in young adults. During normal walking, muscle co-contraction increases with gait speed in young adults, but not in elderly adults. However, no study has compared the effects of speed on muscle co-contraction of the ankle joint during dynamic postural control in young and elderly adults. We compared muscle co-contractions of the ankle joint between young and elderly subjects during a functional stability boundary test at different speeds. Fifteen young adults and 16 community-dwelling elderly adults participated in this study. The task was functional stability boundary tests at different speeds (preferred and fast). Electromyographic evaluations of the tibialis anterior and soleus were recorded. The muscle co-contraction was evaluated using the co-contraction index (CI). There were no statistically significant differences in the postural sway parameters between the two age groups. Elderly subjects showed larger CI in both speed conditions than did the young subjects. CI was higher in the fast speed condition than in the preferred speed condition in the young subjects, but there was no difference in the elderly subjects. Moreover, after dividing the analytical range into phases (acceleration and deceleration phases), the CI was larger in the deceleration phase than in the acceleration phase in both groups, except for the young subjects in the fast speed conditions. Our results showed a greater muscle co-contraction of the ankle joint during dynamic postural control in elderly subjects than in young subjects not only in the preferred speed condition but also in the fast speed condition. In addition, the young subjects showed increased muscle co-contraction in the fast speed condition compared with that in the preferred speed condition; however, the elderly subjects showed no significant difference in muscle co-contraction between the two speed conditions. This indicates

The effects of blocking in the subtropics on the phase speed of the MJO

Science.gov (United States)

Roundy, P. E.

2016-12-01

The phase speed of the MJO might be regulated by many different factors. Previous works have suggested that moist processes govern the phase speed, and our results show that intensification of convection is associated with reduction of phase speed down to about 5 ms-1. However, convection and rainfall decline with declining phase speeds below 5 ms-1. This presentation shows that increased Rossby wave breaking and blocking east of MJO deep convection is associated with reduced phase speed below about 6 ms-1. A wavelet filter is applied to extract time series characterized by selected zonal wavenumbers and frequencies at select equatorial base longitudes over the Indian and West Pacific Oceans. Results show that anomalies of active convection characterized by wavenumber 2 (the dominant scale of MJO convection over the warm pool) are associated with meridional potential vorticity (PV) gradients across the tropics to the east of the active convection that are near climatology for events moving east at 5 ms-1. These gradients are much weaker for slower events. The slowest phase speed events have almost no meridional PV gradients across the tropics between the mean latitudes of the subtropical jet streams, suggesting that jet exit regions occur immediately east of the deep convection, dumping mass in the upper troposphere over the region of suppressed convection. In the absence of PV gradients, synoptic to planetary scale waves moving into that environment break or cease to propagate linearly.

Modeling And Simulation Of Highly Advanced Multilevel Inverter For Speed Control Of Induction Motor

Directory of Open Access Journals (Sweden)

Ravi Raj

2017-02-01

Full Text Available In this Paper the problem of removing Power dissipation from single phase Induction Motor with DC sources is considered by the speed control of Induction Motor with highly advanced 9-Level multi-level Inverter which having approximate zero Harmonics. As the demand of power is increasing day by day. So that we must introduced very advanced Electrical Instruments which having high efficiency and less dissipation of power. The requirement of very advanced Inverter is necessary. Here we are designing a Multi-level Inverter up to the 9-level using IGBT Insulated-gate bipolar transistor by Mat lab which having negligible total harmonic distortion THD thats why it will control the speed of single phase Induction motor which is presently widely used in our daily needs. Also several informative Simulation results verify the authority and truthiness of the proposed Model.

Sliding-Mode Observer for Speed and Position Sensorless Control of Linear-PMSM

Directory of Open Access Journals (Sweden)

Kazraji Saeed Masoumi

2014-05-01

Full Text Available The paper presents a sliding-mode observer that utilizes sigmoid function for speed and position sensorless control of permanent-magnet linear synchronous motor (PMLSM. In conventional sliding mode observer method there are the chattering phenomenon and the phase lag. Thus, in order to avoid the usage of the low pass filter and the phase compensator based on back EMF, in this paper a sliding mode observer with sigmoid function for detecting the back EMF in a PMLSM is designed to estimate the speed and the position of the rotor. Most of conventional sliding mode observers use sign or saturation functions which need low pass filter in order to detect back electromotive force (back EMF. In this paper a sigmoid function is used instead of discontinuous sign function to decrease undesirable chattering phenomenon. By reducing the chattering, detecting of the back EMF can be made directly from switching signal without any low pass filter. Thus the delay time in the proposed observer is eliminated because of the low pass filter. Furthermore, there is no need to compensate phase fault in position and speed estimating of linear-PMSM. Advantages of the proposed observer have been shown by simulation with MATLAB software.

Enabling universal memory by overcoming the contradictory speed and stability nature of phase-change materials.

Science.gov (United States)

Wang, Weijie; Loke, Desmond; Shi, Luping; Zhao, Rong; Yang, Hongxin; Law, Leong-Tat; Ng, Lung-Tat; Lim, Kian-Guan; Yeo, Yee-Chia; Chong, Tow-Chong; Lacaita, Andrea L

2012-01-01

The quest for universal memory is driving the rapid development of memories with superior all-round capabilities in non-volatility, high speed, high endurance and low power. Phase-change materials are highly promising in this respect. However, their contradictory speed and stability properties present a key challenge towards this ambition. We reveal that as the device size decreases, the phase-change mechanism changes from the material inherent crystallization mechanism (either nucleation- or growth-dominated), to the hetero-crystallization mechanism, which resulted in a significant increase in PCRAM speeds. Reducing the grain size can further increase the speed of phase-change. Such grain size effect on speed becomes increasingly significant at smaller device sizes. Together with the nano-thermal and electrical effects, fast phase-change, good stability and high endurance can be achieved. These findings lead to a feasible solution to achieve a universal memory.

Robust control of speed and temperature in a power plant gas turbine.

Science.gov (United States)

Najimi, Ebrahim; Ramezani, Mohammad Hossein

2012-03-01

In this paper, an H(∞) robust controller has been designed for an identified model of MONTAZER GHAEM power plant gas turbine (GE9001E). In design phase, a linear model (ARX model) which is obtained using real data has been applied. Since the turbine has been used in a combined cycle power plant, its speed and also the exhaust gas temperature should be adjusted simultaneously by controlling fuel signals and compressor inlet guide vane (IGV) position. Considering the limitations on the system inputs, the aim of the control is to maintain the turbine speed and the exhaust gas temperature within desired interval under uncertainties and load demand disturbances. Simulation results of applying the proposed robust controller on the nonlinear model of the system (NARX model), fairly fulfilled the predefined aims. Simulations also show the improvement in the performance compared to MPC and PID controllers for the same conditions. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

Rotor Speed Control of a Direct-Driven Permanent Magnet Synchronous Generator-Based Wind Turbine Using Phase-Lag Compensators to Optimize Wind Power Extraction

Directory of Open Access Journals (Sweden)

Ester Hamatwi

2017-01-01

Full Text Available Due to the intermittent nature of wind, the wind power output tends to be inconsistent, and hence maximum power point tracking (MPPT is usually employed to optimize the power extracted from the wind resource at a wide range of wind speeds. This paper deals with the rotor speed control of a 2 MW direct-driven permanent magnet synchronous generator (PMSG to achieve MPPT. The proportional-integral (PI, proportional-derivative (PD, and proportional-integral-derivative (PID controllers have widely been employed in MPPT studies owing to their simple structure and simple design procedure. However, there are a number of shortcomings associated with these controllers; the trial-and-error design procedure used to determine the P, I, and D gains presents a possibility for poorly tuned controller gains, which reduces the accuracy and the dynamic performance of the entire control system. Moreover, these controllers’ linear nature, constricted operating range, and their sensitivity to changes in machine parameters make them ineffective when applied to nonlinear and uncertain systems. On the other hand, phase-lag compensators are associated with a design procedure that is well defined from fundamental principles as opposed to the aforementioned trial-and-error design procedure. This makes the latter controller type more accurate, although it is not well developed yet, and hence it is the focus of this paper. The simulation results demonstrated the effectiveness of the proposed MPPT controller.

Observer Backstepping Control for Variable Speed Wind Turbine

DEFF Research Database (Denmark)

Galeazzi, Roberto; Gryning, Mikkel Peter Sidoroff; Blanke, Mogens

2013-01-01

. The nonlinear controller aims at regulating the generator torque such that an optimal tip-speed ratio can be obtained. Simply relying on the measured rotor angular velocity the proposed observer backstepping controller guarantees global asymptotic tracking of the desired trajectory while maintaining a globally......This paper presents an observer backstepping controller as feasible solution to variable speed control of wind turbines to maximize wind power capture when operating between cut-in and rated wind speeds. The wind turbine is modeled as a two-mass drive-train system controlled by the generator torque...

Interstation phase speed and amplitude measurements of surface waves with nonlinear waveform fitting: application to USArray

Science.gov (United States)

Hamada, K.; Yoshizawa, K.

2015-09-01

A new method of fully nonlinear waveform fitting to measure interstation phase speeds and amplitude ratios is developed and applied to USArray. The Neighbourhood Algorithm is used as a global optimizer, which efficiently searches for model parameters that fit two observed waveforms on a common great-circle path by modulating the phase and amplitude terms of the fundamental-mode surface waves. We introduce the reliability parameter that represents how well the waveforms at two stations can be fitted in a time-frequency domain, which is used as a data selection criterion. The method is applied to observed waveforms of USArray for seismic events in the period from 2007 to 2010 with moment magnitude greater than 6.0. We collect a large number of phase speed data (about 75 000 for Rayleigh and 20 000 for Love) and amplitude ratio data (about 15 000 for Rayleigh waves) in a period range from 30 to 130 s. The majority of the interstation distances of measured dispersion data is less than 1000 km, which is much shorter than the typical average path-length of the conventional single-station measurements for source-receiver pairs. The phase speed models for Rayleigh and Love waves show good correlations on large scales with the recent tomographic maps derived from different approaches for phase speed mapping; for example, significant slow anomalies in volcanic regions in the western Unites States and fast anomalies in the cratonic region. Local-scale phase speed anomalies corresponding to the major tectonic features in the western United States, such as Snake River Plains, Basin and Range, Colorado Plateau and Rio Grande Rift have also been identified clearly in the phase speed models. The short-path information derived from our interstation measurements helps to increase the achievable horizontal resolution. We have also performed joint inversions for phase speed maps using the measured phase and amplitude ratio data of vertical component Rayleigh waves. These maps exhibit

Control of a Stand-Alone Variable Speed Wind Energy Supply System †

Directory of Open Access Journals (Sweden)

Mohamed M. Hamada

2013-04-01

Full Text Available This paper presents a simple control strategy for the operation of a variable speed stand-alone wind turbine with a permanent magnet synchronous generator (PMSG. The PMSG is connected to a three phase resistive load through a switch mode rectifier and a voltage source inverter. Control of the generator side converter is used to achieve maximum power extraction from the available wind power. Control of the DC-DC bidirectional buck-boost converter, which is connected between batteries bank and DC-link voltage, is used to maintain the DC-link voltage at a constant value. It is also used to make the batteries bank stores the surplus of wind energy and supplies this energy to the load during a wind power shortage. The load side voltage source inverter uses a relatively complex vector control scheme to control the output load voltage in terms of amplitude and frequency. The control strategy works under wind speed variation as well as with variable load. Extensive simulation results have been performed using MATLAB/SIMULINK.

Extended Kalman Filter Based Sliding Mode Control of Parallel-Connected Two Five-Phase PMSM Drive System

Directory of Open Access Journals (Sweden)

Tounsi Kamel

2018-01-01

Full Text Available This paper presents sliding mode control of sensor-less parallel-connected two five-phase permanent magnet synchronous machines (PMSMs fed by a single five-leg inverter. For both machines, the rotor speeds and rotor positions as well as load torques are estimated by using Extended Kalman Filter (EKF scheme. Fully decoupled control of both machines is possible via an appropriate phase transposition while connecting the stator windings parallel and employing proposed speed sensor-less method. In the resulting parallel-connected two-machine drive, the independent control of each machine in the group is achieved by controlling the stator currents and speed of each machine under vector control consideration. The effectiveness of the proposed Extended Kalman Filter in conjunction with the sliding mode control is confirmed through application of different load torques for wide speed range operation. Comparison between sliding mode control and PI control of the proposed two-motor drive is provided. The speed response shows a short rise time, an overshoot during reverse operation and settling times is 0.075 s when PI control is used. The speed response obtained by SMC is without overshoot and follows its reference and settling time is 0.028 s. Simulation results confirm that, in transient periods, sliding mode controller remarkably outperforms its counterpart PI controller.

A Mathematical Model of Marine Diesel Engine Speed Control System

Science.gov (United States)

Sinha, Rajendra Prasad; Balaji, Rajoo

2018-02-01

Diesel engine is inherently an unstable machine and requires a reliable control system to regulate its speed for safe and efficient operation. Also, the diesel engine may operate at fixed or variable speeds depending upon user's needs and accordingly the speed control system should have essential features to fulfil these requirements. This paper proposes a mathematical model of a marine diesel engine speed control system with droop governing function. The mathematical model includes static and dynamic characteristics of the control loop components. Model of static characteristic of the rotating fly weights speed sensing element provides an insight into the speed droop features of the speed controller. Because of big size and large time delay, the turbo charged diesel engine is represented as a first order system or sometimes even simplified to a pure integrator with constant gain which is considered acceptable in control literature. The proposed model is mathematically less complex and quick to use for preliminary analysis of the diesel engine speed controller performance.

Belt conveyor dynamics in transient operation for speed control

OpenAIRE

He, D.; Pang, Y.; Lodewijks, G.

2016-01-01

Belt conveyors play an important role in continuous dry bulk material transport, especially at the mining industry. Speed control is expected to reduce the energy consumption of belt conveyors. Transient operation is the operation of increasing or decreasing conveyor speed for speed control. According to literature review, current research rarely takes the conveyor dynamics in transient operation into account. However, in belt conveyor speed control, the conveyor dynamic behaviors are signifi...

Speed control with torque ripple reduction of switched reluctance motor by Hybrid Many Optimizing Liaison Gravitational Search technique

Directory of Open Access Journals (Sweden)

Nutan Saha

2017-06-01

Full Text Available This paper presents a control scheme for simultaneous control of the speed of Switched Reluctance Motor (SRM and minimizing the torque ripple employing Hybrid Many Optimizing Liaison Gravitational Search Algorithm (Hybrid MOLGSA technique. The control mechanism includes two controlling loops, the outer loop is governed for speed control and a current controller for the inner loop, intelligent selection of turn on and turn off angle for a 60 KW, 3-phase 6/8 SRM. It is noticed that the torque ripple coefficient, ISE of speed & current are reduced by 12.81%, 38.60%, 16.74% respectively by Hybrid MOLGSA algorithm compared to Gravitational Search Algorithm (GSA algorithm. It is also observed that the settling times for the controller using the parameter values for obtaining best values of torque ripple, Integral square error of speed and current are reduced by 51.25%, 58.04% and 59.375% by proposed Hybrid MOLGSA algorithm compared to the GSA algorithm.

Multilayer SnSb4-SbSe Thin Films for Phase Change Materials Possessing Ultrafast Phase Change Speed and Enhanced Stability.

Science.gov (United States)

Liu, Ruirui; Zhou, Xiao; Zhai, Jiwei; Song, Jun; Wu, Pengzhi; Lai, Tianshu; Song, Sannian; Song, Zhitang

2017-08-16

A multilayer thin film, comprising two different phase change material (PCM) components alternatively deposited, provides an effective means to tune and leverage good properties of its components, promising a new route toward high-performance PCMs. The present study systematically investigated the SnSb 4 -SbSe multilayer thin film as a potential PCM, combining experiments and first-principles calculations, and demonstrated that these multilayer thin films exhibit good electrical resistivity, robust thermal stability, and superior phase change speed. In particular, the potential operating temperature for 10 years is shown to be 122.0 °C and the phase change speed reaches 5 ns in the device test. The good thermal stability of the multilayer thin film is shown to come from the formation of the Sb 2 Se 3 phase, whereas the fast phase change speed can be attributed to the formation of vacancies and a SbSe metastable phase. It is also demonstrated that the SbSe metastable phase contributes to further enhancing the electrical resistivity of the crystalline state and the thermal stability of the amorphous state, being vital to determining the properties of the multilayer SnSb 4 -SbSe thin film.

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

Directory of Open Access Journals (Sweden)

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.

Speed Controlled Belt Conveyors: Drives and Mechanical Considerations

Directory of Open Access Journals (Sweden)

BEBIC, M. Z.

2018-02-01

Full Text Available The paper presents variable speed belt conveyor system where the reference speed is changed in order to achieve improved energy efficiency of operation. The recorded measurements show that belt tension varies within the same limits as under constant speed operation. These results introduce a new insight of the present state of the art in variable speed belt conveyor drives. The system is realized with remote control from the control center on an open pit mine. The structure of the multi-motor drive system of a single conveyor, as well as of the network-based control system distributed among belt conveyor stations and the control center are shown. Speed control of a belt conveyor system is organized to provide better utilization of the available material cross section on the belt and reduced electrical energy consumption of the drive. The experimental results obtained on the system prove that, under existing constraints, the applied algorithm has not introduced additional stress to the belt or mechanical assemblies during acceleration and deceleration processes, while providing higher energy efficiency of operation.

Torque- and Speed Control of a Pitch Regulated Wind Turbine

Energy Technology Data Exchange (ETDEWEB)

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.

A new phase coding method using a slice selection gradient for high speed flow velocity meaurements in NMR tomography

International Nuclear Information System (INIS)

Oh, C.H.; Cho, Z.H.; California Univ., Irvine

1986-01-01

A new phase coding method using a selection gradient for high speed NMR flow velocity measurements is introduced and discussed. To establish a phase-velocity relationship of flow under the slice selection gradient and spin-echo RF pulse, the Bloch equation was numerically solved under the assumption that only one directional flow exists, i.e. in the direction of slice selection. Details of the numerical solution of the Bloch equation and techniques related to the numerical computations are also given. Finally, using the numerical calculation, high speed flow velocity measurement was attempted and found to be in good agreement with other complementary controlled measurements. (author)

Direct Torque Control of a Small Wind Turbine with a Sliding-Mode Speed Controller

Science.gov (United States)

Sri Lal Senanayaka, Jagath; Karimi, Hamid Reza; Robbersmyr, Kjell G.

2016-09-01

In this paper. the method of direct torque control in the presence of a sliding-mode speed controller is proposed for a small wind turbine being used in water heating applications. This concept and control system design can be expanded to grid connected or off-grid applications. Direct torque control of electrical machines has shown several advantages including very fast dynamics torque control over field-oriented control. Moreover. the torque and flux controllers in the direct torque control algorithms are based on hvsteretic controllers which are nonlinear. In the presence of a sliding-mode speed control. a nonlinear control system can be constructed which is matched for AC/DC conversion of the converter that gives fast responses with low overshoots. The main control objectives of the proposed small wind turbine can be maximum power point tracking and soft-stall power control. This small wind turbine consists of permanent magnet synchronous generator and external wind speed. and rotor speed measurements are not required for the system. However. a sensor is needed to detect the rated wind speed overpass events to activate proper speed references for the wind turbine. Based on the low-cost design requirement of small wind turbines. an available wind speed sensor can be modified. or a new sensor can be designed to get the required measurement. The simulation results will be provided to illustrate the excellent performance of the closed-loop control system in entire wind speed range (4-25 m/s).

Active surge control for variable speed axial compressors.

Science.gov (United States)

Lin, Shu; Yang, Chunjie; Wu, Ping; Song, Zhihuan

2014-09-01

This paper discusses active surge control in variable speed axial compressors. A compression system equipped with a variable area throttle is investigated. Based on a given compressor model, a fuzzy logic controller is designed for surge control and a proportional speed controller is used for speed control. The fuzzy controller uses measurements of the change of pressure rise as well as the change of mass flow to determine the throttle opening. The presented approach does not require the knowledge of system equilibrium or the surge line. Numerical simulations show promising results. The proposed fuzzy logic controller performs better than a backstepping controller and is capable to suppress surge at different operating points. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Bandwidth Controllable Tunable Filter for Hyper-/Multi-Spectral Imager, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — This SBIR Phase I proposal introduces a fast speed bandwidth controllable tunable filter for hyper-/multi-spectral (HS/MS) imagers. It dynamically passes a variable...

High-speed X-ray phase tomography with Talbot interferometer and fringe scanning method

International Nuclear Information System (INIS)

Kibayashi, Shunsuke; Harasse, Sébastien; Yashiro, Wataru; Momose, Atsushi

2012-01-01

High-speed X-ray phase tomography based on the Fourier-transform method has been demonstrated with an X-ray Talbot interferometer using white synchrotron radiation. We report the experimental results of high-speed X-ray phase tomography with fringe-scanning method instead of Fourier-transform method to improve spatial resolution without a considerable increase of scan time. To apply fringe-scanning method to high speed tomography, we tested a scan that is a synchronous combination of one-way continuous movements of the sample rotation and the grating displacement. When this scanning method was combined with X-ray phase tomography, we were able to obtain a scan time of 5 s. A comparison of the image quality derived with the conventional approach and with the proposed approach using the fringe-scanning method showed that the latter had better spatial resolution.

Electromagnetic phenomena analysis in brushless DC motor with speed control using PWM method

Science.gov (United States)

Ciurys, Marek Pawel

2017-12-01

Field-circuit model of a brushless DC motor with speed control using PWM method was developed. Waveforms of electrical and mechanical quantities of the designed motor with a high pressure vane pump built in a rotor of the motor were computed. Analysis of electromagnetic phenomena in the system: single phase AC network - converter - BLDC motor was carried out.

Belt conveyor dynamics in transient operation for speed control

NARCIS (Netherlands)

He, D.; Pang, Y.; Lodewijks, G.

2016-01-01

Belt conveyors play an important role in continuous dry bulk material transport, especially at the mining industry. Speed control is expected to reduce the energy consumption of belt conveyors. Transient operation is the operation of increasing or decreasing conveyor speed for speed control.

Flicker Mitigation by Speed Control of Permanent Magnet Synchronous Generator Variable-Speed Wind Turbines

DEFF Research Database (Denmark)

Hu, Weihao; Zhang, Yunqian; Chen, Zhe

2013-01-01

operation. A new method of flicker mitigation by controlling the rotational speed is proposed. It smoothes the 3p active power oscillations from wind shear and tower shadow effects of the wind turbine by varying the rotational speed of the PMSG. Simulation results show that damping the 3p active power...... oscillation by using the flicker mitigation speed controller is an effective means for flicker mitigation of variable speed wind turbines with full-scale back-to-back power converters and PMSG during continuous operation.......Grid-connected wind turbines are fluctuating power sources that may produce flicker during continuous operation. This paper presents a simulation model of a MW-level variable speed wind turbine with a full-scale back-to-back power converter and permanent magnet synchronous generator (PMSG...

Research on fuzzy PID control to electronic speed regulator

Science.gov (United States)

Xu, Xiao-gang; Chen, Xue-hui; Zheng, Sheng-guo

2007-12-01

As an important part of diesel engine, the speed regulator plays an important role in stabilizing speed and improving engine's performance. Because there are so many model parameters of diesel-engine considered in traditional PID control and these parameters present non-linear characteristic.The method to adjust engine speed using traditional PID is not considered as a best way. Especially for the diesel-engine generator set. In this paper, the Fuzzy PID control strategy is proposed. Some problems about its utilization in electronic speed regulator are discussed. A mathematical model of electric control system for diesel-engine generator set is established and the way of the PID parameters in the model to affect the function of system is analyzed. And then it is proposed the differential coefficient must be applied in control design for reducing dynamic deviation of system and adjusting time. Based on the control theory, a study combined control with PID calculation together for turning fuzzy PID parameter is implemented. And also a simulation experiment about electronic speed regulator system was conducted using Matlab/Simulink and the Fuzzy-Toolbox. Compared with the traditional PID Algorithm, the simulated results presented obvious improvements in the instantaneous speed governing rate and steady state speed governing rate of diesel-engine generator set when the fuzzy logic control strategy used.

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

DEFF Research Database (Denmark)

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

2015-01-01

by the proposed controller for an improved transient and steady state performances. The discrete wavelet transform has been used to decompose the error speed into different frequency components and the fuzzy logic is used to generate the scaling gains of the wavelet controller. The complete model of the proposed...

Velocity control in three-phase induction motors using PIC; Controle de velocidade de motor de inducao trifasico usando PIC

Energy Technology Data Exchange (ETDEWEB)

Marcelino, M.A.; Silva, G.B.S.; Grandinetti, F.J. [Universidade Estadual Paulista (UNESP), Guaratingueta, SP (Brazil). Fac. de Engenharia; Universidade de Taubate (UNITAU), SP (Brazil)], Emails: abud@feg.unesp.br, gabonini@yahoo.com.br, grandinetti@unitau.br

2009-07-01

This paper presents a technique for speed control three-phase induction motor using the pulse width modulation (PWM), in open loop while maintaining the tension for constant frequency. The technique is adapted from a thesis entitled 'Control of the three-phase induction motor, using discrete PWM generation, optimized and synchronized', where studies are presented aimed at their application in home appliances, to eliminate mechanical parts, replaced by low cost electronic control, thus having a significant reduction in power consumption. Initially the experiment was done with the Intel 80C31 micro controller. In this paper, the PWM modulation is implemented using a PIC micro controller, and the speed control kept a low profile, based on tables, synchronized with transitions and reduced generation of harmonics in the network. Confirmations were made using the same process of building tables, but takes advantage of the program of a RISC device.

Speed control of switched reluctance motor using sliding mode control strategy

Energy Technology Data Exchange (ETDEWEB)

John, G. [Kenetech Windpower, Livermore, CA (United States); Eastham, A.R. [Queen`s Univ., Kingston, Ontario (Canada). Dept. of Electrical Engineering

1995-12-31

A robust speed drive system for a switched reluctance motor (SRM) using sliding mode control strategy (SLMC) is presented. After reviewing the operation of an SRM drive, a SLMC based scheme is formulated to control the drive speed. The scheme is implemented using a micro-controller and a high resolution position sensor. The parameter insensitive characteristics are demonstrated through computer simulations and experimental verification.

Implementation of FPGA based PID Controller for DC Motor Speed Control System

Directory of Open Access Journals (Sweden)

Savita SONOLI

2010-03-01

Full Text Available In this paper, the implementation of software module using ‘VHDL’ for Xilinx FPGA (XC3S400 based PID controller for DC motor speed control system is presented. The tools used for building and testing the software modules are Xilinx ISE 9.2i and ModelSim XE III 6.3c. Before verifying the design on FPGA the complete design is simulated using Modelsim Simulation tool. A test bench is written where the set speed can be changed for the motor. It is observed that the motor speed gradually changes to the set speed and locks to the set speed.

LH2 three-phase pump control circuit description

International Nuclear Information System (INIS)

Pierce, W.

1977-05-01

A brief description and circuit drawings are given for a pump control system. The pump is used to circulate liquid hydrogen through the cell and heat exchanger of an LH 2 target. The pump is powered by three-phase 60 cycle power, and the control unit is powered from a positive and negative 24 V dc supply available in the NIM Bin. The control unit is packaged in a double-width NIM module. Drawings are given for the pump speed indicator, function generator, and power supply

Fuzzy Logic Controlled Solar Module for Driving Three- Phase Induction Motor

Science.gov (United States)

Afiqah Zainal, Nurul; Sooi Tat, Chan; Ajisman

2016-02-01

Renewable energy produced by solar module gives advantages for generated three- phase induction motor in remote area. But, solar module's ou tput is uncertain and complex. Fuzzy logic controller is one of controllers that can handle non-linear system and maximum power of solar module. Fuzzy logic controller used for Maximum Power Point Tracking (MPPT) technique to control Pulse-Width Modulation (PWM) for switching power electronics circuit. DC-DC boost converter used to boost up photovoltaic voltage to desired output and supply voltage source inverter which controlled by three-phase PWM generated by microcontroller. IGBT switched Voltage source inverter (VSI) produced alternating current (AC) voltage from direct current (DC) source to control speed of three-phase induction motor from boost converter output. Results showed that, the output power of solar module is optimized and controlled by using fuzzy logic controller. Besides that, the three-phase induction motor can be drive and control using VSI switching by the PWM signal generated by the fuzzy logic controller. This concluded that the non-linear system can be controlled and used in driving three-phase induction motor.

Simulation of load traffic and steeped speed control of conveyor

Science.gov (United States)

Reutov, A. A.

2017-10-01

The article examines the possibilities of the step control simulation of conveyor speed within Mathcad, Simulink, Stateflow software. To check the efficiency of the control algorithms and to more accurately determine the characteristics of the control system, it is necessary to simulate the process of speed control with real values of traffic for a work shift or for a day. For evaluating the belt workload and absence of spillage it is necessary to use empirical values of load flow in a shorter period of time. The analytical formulas for optimal speed step values were received using empirical values of load. The simulation checks acceptability of an algorithm, determines optimal parameters of regulation corresponding to load flow characteristics. The average speed and the number of speed switching during simulation are admitted as criteria of regulation efficiency. The simulation example within Mathcad software is implemented. The average conveyor speed decreases essentially by two-step and three-step control. A further increase in the number of regulatory steps decreases average speed insignificantly but considerably increases the intensity of the speed switching. Incremental algorithm of speed regulation uses different number of stages for growing and reducing load traffic. This algorithm allows smooth control of the conveyor speed changes with monotonic variation of the load flow. The load flow oscillation leads to an unjustified increase or decrease of speed. Work results can be applied at the design of belt conveyors with adjustable drives.

Hydrodynamics of phase transition fronts and the speed of sound in the plasma

International Nuclear Information System (INIS)

Leitao, Leonardo; Mégevand, Ariel

2015-01-01

The growth of bubbles in cosmological first-order phase transitions involves nontrivial hydrodynamics. For that reason, the study of the propagation of phase transition fronts often requires several approximations. A frequently used approximation consists in describing the two phases as being composed only of radiation and vacuum energy (the so-called bag equation of state). We show that, in realistic models, the speed of sound in the low-temperature phase is generally smaller than that of radiation, and we study the hydrodynamics in such a situation. We find in particular that a new kind of hydrodynamical solution may be possible, which does not arise in the bag model. We obtain analytic results for the efficiency of the transfer of latent heat to bulk motions of the plasma, as a function of the speed of sound in each phase

Hydrodynamics of phase transition fronts and the speed of sound in the plasma

Energy Technology Data Exchange (ETDEWEB)

Leitao, Leonardo, E-mail: lleitao@mdp.edu.ar; Mégevand, Ariel, E-mail: megevand@mdp.edu.ar

2015-02-15

The growth of bubbles in cosmological first-order phase transitions involves nontrivial hydrodynamics. For that reason, the study of the propagation of phase transition fronts often requires several approximations. A frequently used approximation consists in describing the two phases as being composed only of radiation and vacuum energy (the so-called bag equation of state). We show that, in realistic models, the speed of sound in the low-temperature phase is generally smaller than that of radiation, and we study the hydrodynamics in such a situation. We find in particular that a new kind of hydrodynamical solution may be possible, which does not arise in the bag model. We obtain analytic results for the efficiency of the transfer of latent heat to bulk motions of the plasma, as a function of the speed of sound in each phase.

Evaluation of train-speed control algorithms

Energy Technology Data Exchange (ETDEWEB)

Slavik, M.M. [BKS Advantech (Pty.) Ltd., Pretoria (South Africa)

2000-07-01

A relatively simple and fast simulator has been developed and used for the preliminary testing of train cruise-control algorithms. The simulation is done in software on a PC. The simulator is used to gauge the consequences and feasibility of a cruise-control strategy prior to more elaborate testing and evaluation. The tool was used to design and pre-test a train-cruise control algorithm called NSS, which does not require knowledge of exact train mass, vertical alignment, or actual braking force. Only continuous measurements on the speed of the train and electrical current are required. With this modest input, the NSS algorithm effected speed changes smoothly and efficiently for a wide range of operating conditions. (orig.)

A Position Sensorless Control Method for SRM Based on Variation of Phase Inductance

Science.gov (United States)

Komatsuzaki, Akitomo; Miki, Ichiro

Switched reluctance motor (SRM) drives are suitable for variable speed industrial applications because of the simple structure and high-speed capability. However, it is necessary to detect the rotor position with a position sensor attached to the motor shaft. The use of the sensor increases the cost of the drive system and machine size, and furthermore the reliability of the system is reduced. Therefore, several approaches to eliminate the position sensor have already been reported. In this paper, a position sensorless control method based on the variation of the phase inductance is described. The phase inductance regularly varies with the rotor position. The SRM is controlled without the position sensor using the de-fluxing period and the phase inductance. The turn-off timing is determined by computing the difference of angle between the sampling point and the aligned point and the variation of angle during the de-fluxing period. In the magnetic saturation region, the phase inductance at the current when the effect of the saturation starts is computed and the sensorless control can be carried out using this inductance. Experimental results show that the SRM is well controlled without the position sensor using the proposed method.

Flicker Mitigation by Speed Control of Permanent Magnet Synchronous Generator Variable-Speed Wind Turbines

Directory of Open Access Journals (Sweden)

Yanting Hu

2013-07-01

Full Text Available Grid-connected wind turbines are fluctuating power sources that may produce flicker during continuous operation. This paper presents a simulation model of a MW-level variable speed wind turbine with a full-scale back-to-back power converter and permanent magnet synchronous generator (PMSG developed in the simulation tool of PSCAD/EMTDC. Flicker emission of this system is investigated. The 3p (three times per revolution power oscillation due to wind shear and tower shadow effects is the significant part in the flicker emission of variable speed wind turbines with PMSG during continuous operation. A new method of flicker mitigation by controlling the rotational speed is proposed. It smoothes the 3p active power oscillations from wind shear and tower shadow effects of the wind turbine by varying the rotational speed of the PMSG. Simulation results show that damping the 3p active power oscillation by using the flicker mitigation speed controller is an effective means for flicker mitigation of variable speed wind turbines with full-scale back-to-back power converters and PMSG during continuous operation.

Efficient speed control of induction motor using RBF based model reference adaptive control method

OpenAIRE

Kilic, Erdal; Ozcalik, Hasan Riza; Yilmaz, Saban

2017-01-01

This paper proposes a model reference adaptive speed controller based on artificial neural network for induction motor drives. The performance of traditional feedback controllers has been insufficient in speed control of induction motors due to nonlinear structure of the system, changing environmental conditions, and disturbance input effects. A successful speed control of induction motor requires a nonlinear control system. On the other hand, in recent years, it has been demonstrated that ar...

Regulating vacuum pump speed with feedback control

International Nuclear Information System (INIS)

Ludington, D.C.; Aneshansley, D.J.; Pellerin, R.; Guo, F.

1992-01-01

Considerable energy is wasted by the vacuum pump/motor on dairy farms. The output capacity (m 3 /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

Control design for a pitch-regulated, variable speed wind turbine

DEFF Research Database (Denmark)

Hansen, M.H.; Hansen, Anca Daniela; Larsen, Torben J.

2005-01-01

The three different controller designs presented herein are similar and all based on PI-regulation of rotor speed and power through the collective blade pitch angle and generator moment. The aeroelastic and electrical modelling used for the time-domainanalysis of these controllers are however...... different, which makes a directly quantitative comparison difficult. But there are some observations of similar behaviours should be mentioned: • Very similar step responses in rotor speed, pitch angle, and powerare seen for simulations with steps in wind speed. • All controllers show a peak in power...... for wind speed step-up over rated wind speed, which can be almost removed by changing the parameters of the frequency converter. • Responses of rotor speed, pitchangle, and power for different simulations with turbulent inflow are similar for all three controllers. Again, there seems to be an advantage...

Sliding Mode Control of a Variable- Speed Wind Energy Conversion System Using a Squirrel Cage Induction Generator

Directory of Open Access Journals (Sweden)

Mohamed Zribi

2017-05-01

Full Text Available This paper deals with the control of a variable-speed wind energy conversion (WEC system using a squirrel cage induction generator (SCIG connected to the grid through a back-to-back three phase (AC-DC-AC power converter. The sliding mode control technique is used to control the WEC system. The objective of the controllers is to force the states of the system to track their desired states. One controller is used to regulate the generator speed and the flux so that maximum power is extracted from the wind. Another controller is used to control the grid side converter, which controls the DC bus voltage and the active and reactive powers injected into the grid. The performance of the controlled wind energy conversion system is verified through MATLAB simulations, which show that the controlled system performs well.

Performance Analysis of Phase Controlled Unidirectional and Bidirectional AC Voltage Controllers

Directory of Open Access Journals (Sweden)

Abdul Sattar Larik

2011-01-01

Full Text Available AC voltage controllers are used to vary the output ac voltage from a fixed ac input source. They are also commonly called ac voltage regulators or ac choppers. The output voltage is either controlled by PAC (Phase Angle Control method or on-off control method. Due to various advantages of ac voltage controllers, such as high efficiency, simplicity, low cost and ability to control large amount of power they efficiently control the speed of ac motors, light dimming and industrial heating, etc. These converters are variable structure systems and generate harmonics during the operation which will affect the power quality when connected to system network. During the last couple of years, a number of new semiconductor devices and various power electronic converters has been introduced. Accordingly the subject of harmonics and its problems are of great concern to power industry and customers. In this research work, initially the simulation models of single phase unidirectional and bidirectional ac voltage controllers were developed by using MATLAB software. The harmonics of these models are investigated by simulation. In the end, the harmonics were also analyzed experimentally. The simulated as well as experimental results are presented.

Fuzzy Logic Controlled Solar Module for Driving Three- Phase Induction Motor

International Nuclear Information System (INIS)

Zainal, Nurul Afiqah; Tat, Chan Sooi; Ajisman

2016-01-01

Renewable energy produced by solar module gives advantages for generated three- phase induction motor in remote area. But, solar module's output is uncertain and complex. Fuzzy logic controller is one of controllers that can handle non-linear system and maximum power of solar module. Fuzzy logic controller used for Maximum Power Point Tracking (MPPT) technique to control Pulse-Width Modulation (PWM) for switching power electronics circuit. DC-DC boost converter used to boost up photovoltaic voltage to desired output and supply voltage source inverter which controlled by three-phase PWM generated by microcontroller. IGBT switched Voltage source inverter (VSI) produced alternating current (AC) voltage from direct current (DC) source to control speed of three-phase induction motor from boost converter output. Results showed that, the output power of solar module is optimized and controlled by using fuzzy logic controller. Besides that, the three-phase induction motor can be drive and control using VSI switching by the PWM signal generated by the fuzzy logic controller. This concluded that the non-linear system can be controlled and used in driving three-phase induction motor. (paper)

Apparatus for decelerating the dropping speed of a control rod

International Nuclear Information System (INIS)

Shirakawa, Toshihisa.

1975-01-01

Object: To reduce the dropping speed (i.e. withdrawal) of a control rod of the upward insertion type in a BWR type reactor without reducing the speed of insertion. Structure: A control rod is provided with a flaring lower end so as to constitute a speed limiter which is penerated by vertically extending and upwardly open flow ducts that each have a narrow opening and flare upwardly. Thus, at the time of insertion of the control rod, the resistance offered thereto by the surrounding fluid is reduced to provide increased insertion speed. On the other hand, at the time of withdrawal the resistance offered by the fluid is increased to reduce the dropping speed of the control rod. (Ikeda, J.)

REDUCTION IN CUTS SPEED AT THE BEGINNING OF A SORTING SIDINGS, EQUIPPED WITH QUASI-CONTINUOUS SPEED CONTROL SYSTEM

Directory of Open Access Journals (Sweden)

O. A. Nazarov

2016-08-01

Full Text Available Purpose. Clear and uninterrupted operation of humps depends on the quality of technical equipment and control technology of cuts speed. Technology of interval and purposive regulation of cuts speed is used at most humps. The article discusses ways to reduce the cuts rolling speed to a safe level at the beginning of the sorting sidings equipped with quasi-continuous speed control system. Methodology. It proposed three fundamentally different ways to reduce the cuts rolling speed at the beginning of the sorting siding. The analysis of the ways to reduce cuts rolling speed to a safe level at the beginning of the sorting sidings was conducted using simulation the process of cuts rolling from humps equipped with quasi-continuous speed control. Findings. As a result of analysis, the inappropriateness of opposite elevation using on the roll-out part of the hump after the last separation switch point. Spot regulators of cars speed can be used to reduce the cuts rolling speed at the beginning of the sorting siding, but this leads to a division conditions deterioration on the last separating switch points of long cuts with the following after them short cuts. Reducing the cuts rolling speed at the beginning of the sorting siding can be carried out using the beam on a stationary wagon retarders park brake position. Control Algorithm park brake position is quite simple. All produce should be unhooked from it at a safe speed. If the accuracy of the implementation of the set speed output to unhook from the park brake position is low, it is possible to eliminate the error of point regulators cars speed. Originality. The question where to start location point of wagon retarders zone to reduce speed to cut level requires additional research. Reducing rolling cut the speed at the beginning of the sorting sidings can be carried out using the beam on a stationary wagon retarders park brake position. Practical value. Control Algorithm park brake position is quite

Speed limiter integrated fatigue analyzer (SLIFA) for speed and fatigue control on diesel engine truck and bus

Science.gov (United States)

Wahyudi, Haris; Pranoto, Hadi; Leman, A. M.; Sebayang, Darwin; Baba, I.

2017-09-01

Every second, the number of road traffic deaths is increased globally with millions more sustaining severe injuries and living with long-term adverse health consequences. Jakarta alone in year 2015 had recorded 556 people died due to road accidents, approximately reached 6.231 road accident cases. The identified major contributory factors of such unfortunate events are both driver fatigue and over speeding habit especially related to the driving of truck and bus. This paper presents the idea on how to control the electronic system from input fuel system of injection pump and the combustion chamber engine will control the valve solenoid in injection pump which can lock and fuel will stop for moment, and speed limit can be success, by using sensor heart rate we can input reduce speed limit when fatigue detection driver. Integration process this tool can be relevant when Speed Limiter Integrated Fatigue Analyser (SLIFA) trial in the diesel engine for truck and bus, the result of this research Speed Limiter Integrated Fatigue Analyser (SLIFA) able to control speed of diesel engine for truck and bus almost 30km/h, 60km/h, and until 70 km/h. The installation of the sensor heart rate as the input speed limit SLIFA would work when the driver is detected to be in the fatigue condition. We make Speed Limiter Integrated Fatigue Analyser (SLIFA) for control and monitoring system for diesel engine in truck and bus. Speed Limiter Integrated Fatigue Analyser (SLIFA) system can save the historical of the speed record, fatigue, rpm, and body temperature of the driver.

Implementation Of Automatic Wiper Speed Control And Headlight Modes Control Systems Using Fuzzy Logic

OpenAIRE

ThetKoKo; ZawMyoTun; Hla Myo Tun

2015-01-01

Abstract This research paper describes the design and simulation of the automatic wiper speed and headlight modes controllers using fuzzy logic. This proposed system consists of a fuzzy logic controller to control a cars wiper speed and headlight modes. The automatic wiper system detects the rain and its intensity. And according to the rain intensity the wiper speed is automatically controlled. Headlight modes automatically changes either from low beam mode to high beam mode or form high beam...

PID Neural Network Based Speed Control of Asynchronous Motor Using Programmable Logic Controller

Directory of Open Access Journals (Sweden)

MARABA, V. A.

2011-11-01

Full Text Available This paper deals with the structure and characteristics of PID Neural Network controller for single input and single output systems. PID Neural Network is a new kind of controller that includes the advantages of artificial neural networks and classic PID controller. Functioning of this controller is based on the update of controller parameters according to the value extracted from system output pursuant to the rules of back propagation algorithm used in artificial neural networks. Parameters obtained from the application of PID Neural Network training algorithm on the speed model of the asynchronous motor exhibiting second order linear behavior were used in the real time speed control of the motor. Programmable logic controller (PLC was used as real time controller. The real time control results show that reference speed successfully maintained under various load conditions.

Speed Control Design of Permanent Magnet Synchronous Motor using TakagiSugeno Fuzzy Logic Control

Directory of Open Access Journals (Sweden)

Ahmad Asri Abd Samat

2017-12-01

Full Text Available This paper proposes a speed control design of Permanent Magnet Synchronous Motor (PMSM using Field Oriented Control (FOC. The focus is to design a speed control using Takagi — Sugeno Fuzzy Logic Control (T-S FLS. These systems will replace the conventional method which is proportional-integral (PI. The objective of this paper is to study the T—S Fuzzy Inference System (FIS speed regulator and acceleration observer for PMSM. The scope of study basically is to design and analyse the Takagi Sugeno FLC and the PMSM. This paper also will describe the methodology and process of modelling the PMSM including data analysis. The simulation work is implemented in Matlab-Simulink to verify the control method. The effectiveness of this proposed control method was confirmed through various range of speed and torque variation.

Phase dependence of transport-aperture coordination variability reveals control strategy of reach-to-grasp movements.

Science.gov (United States)

Rand, Miya K; Shimansky, Y P; Hossain, Abul B M I; Stelmach, George E

2010-11-01

Based on an assumption of movement control optimality in reach-to-grasp movements, we have recently developed a mathematical model of transport-aperture coordination (TAC), according to which the hand-target distance is a function of hand velocity and acceleration, aperture magnitude, and aperture velocity and acceleration (Rand et al. in Exp Brain Res 188:263-274, 2008). Reach-to-grasp movements were performed by young adults under four different reaching speeds and two different transport distances. The residual error magnitude of fitting the above model to data across different trials and subjects was minimal for the aperture-closure phase, but relatively much greater for the aperture-opening phase, indicating considerable difference in TAC variability between those phases. This study's goal is to identify the main reasons for that difference and obtain insights into the control strategy of reach-to-grasp movements. TAC variability within the aperture-opening phase of a single trial was found minimal, indicating that TAC variability between trials was not due to execution noise, but rather a result of inter-trial and inter-subject variability of motor plan. At the same time, the dependence of the extent of trial-to-trial variability of TAC in that phase on the speed of hand transport was sharply inconsistent with the concept of speed-accuracy trade-off: the lower the speed, the larger the variability. Conversely, the dependence of the extent of TAC variability in the aperture-closure phase on hand transport speed was consistent with that concept. Taking into account recent evidence that the cost of neural information processing is substantial for movement planning, the dependence of TAC variability in the aperture-opening phase on task performance conditions suggests that it is not the movement time that the CNS saves in that phase, but the cost of neuro-computational resources and metabolic energy required for TAC regulation in that phase. Thus, the CNS

New Intelligent Transmission Concept for Hybrid Mobile Robot Speed Control

Directory of Open Access Journals (Sweden)

Nazim Mir-Nasiri

2008-11-01

Full Text Available This paper presents a new concept of a mobile robot speed control by using two degree of freedom gear transmission. The developed intelligent speed controller utilizes a gear box which comprises of epicyclic gear train with two inputs, one coupled with the engine shaft and another with the shaft of a variable speed dc motor. The net output speed is a combination of the two input speeds and is governed by the transmission ratio of the planetary gear train. This new approach eliminates the use of a torque converter which is otherwise an indispensable part of all available automatic transmissions, thereby reducing the power loss that occurs in the box during the fluid coupling. By gradually varying the speed of the dc motor a stepless transmission has been achieved. The other advantages of the developed controller are pulling over and reversing the vehicle, implemented by intelligent mixing of the dc motor and engine speeds. This approach eliminates traditional braking system in entire vehicle design. The use of two power sources, IC engine and battery driven DC motor, utilizes the modern idea of hybrid vehicles. The new mobile robot speed controller is capable of driving the vehicle even in extreme case of IC engine failure, for example, due to gas depletion..

New Intelligent Transmission Concept for Hybrid Mobile Robot Speed Control

Directory of Open Access Journals (Sweden)

Nazim Mir-Nasiri

2005-09-01

Full Text Available This paper presents a new concept of a mobile robot speed control by using two degree of freedom gear transmission. The developed intelligent speed controller utilizes a gear box which comprises of epicyclic gear train with two inputs, one coupled with the engine shaft and another with the shaft of a variable speed dc motor. The net output speed is a combination of the two input speeds and is governed by the transmission ratio of the planetary gear train. This new approach eliminates the use of a torque converter which is otherwise an indispensable part of all available automatic transmissions, thereby reducing the power loss that occurs in the box during the fluid coupling. By gradually varying the speed of the dc motor a stepless transmission has been achieved. The other advantages of the developed controller are pulling over and reversing the vehicle, implemented by intelligent mixing of the dc motor and engine speeds. This approach eliminates traditional braking system in entire vehicle design. The use of two power sources, IC engine and battery driven DC motor, utilizes the modern idea of hybrid vehicles. The new mobile robot speed controller is capable of driving the vehicle even in extreme case of IC engine failure, for example, due to gas depletion.

Filtering and Control of High Speed Motor Current in a Flywheel Energy Storage System

Science.gov (United States)

Kenny, Barbara H.; Santiago, Walter

2004-01-01

The NASA Glenn Research Center has been developing technology to enable the use of high speed flywheel energy storage units in future spacecraft for the last several years. An integral part of the flywheel unit is the three phase motor/generator that is used to accelerate and decelerate the flywheel. The motor/generator voltage is supplied from a pulse width modulated (PWM) inverter operating from a fixed DC voltage supply. The motor current is regulated through a closed loop current control that commands the necessary voltage from the inverter to achieve the desired current. The current regulation loop is the innermost control loop of the overall flywheel system and, as a result, must be fast and accurate over the entire operating speed range (20,000 to 60,000 rpm) of the flywheel. The voltage applied to the motor is a high frequency PWM version of the DC bus voltage that results in the commanded fundamental value plus higher order harmonics. Most of the harmonic content is at the switching frequency and above. The higher order harmonics cause a rapid change in voltage to be applied to the motor that can result in large voltage stresses across the motor windings. In addition, the high frequency content in the motor causes sensor noise in the magnetic bearings that leads to disturbances for the bearing control. To alleviate these problems, a filter is used to present a more sinusoidal voltage to the motor/generator. However, the filter adds additional dynamics and phase lag to the motor system that can interfere with the performance of the current regulator. This paper will discuss the tuning methodology and results for the motor/generator current regulator and the impact of the filter on the control. Results at speeds up to 50,000 rpm are presented.

Proposed torque optimized behavior for digital speed control of induction motors

Energy Technology Data Exchange (ETDEWEB)

Metwally, H.M.B.; El-Shewy, H.M.; El-Kholy, M.M. [Zagazig Univ., Dept. of Electrical Engineering, Zagazig (Egypt); Abdel-Kader, F.E. [Menoufyia Univ., Dept. of Electrical Engineering, Menoufyia (Egypt)

2002-09-01

In this paper, a control strategy for speed control of induction motors with field orientation is proposed. The proposed method adjusts the output voltage and frequency of the converter to operate the motor at the desired speed with maximum torque per ampere at all load torques keeping the torque angle equal to 90 deg. A comparison between the performance characteristics of a 2 hp induction motor using three methods of speed control is presented. These methods are the proposed method, the direct torque control method and the constant V/f method. The comparison showed that better performance characteristics are obtained using the proposed speed control strategy. A computer program, based on this method, is developed. Starting from the motor parameters, the program calculates a data set for the stator voltage and frequency required to obtain maximum torque per ampere at any motor speed and load torque. This data set can be used by the digital speed control system of induction motors. (Author)

Hybrid I-f starting and observer-based Ssnsorless control of single-phase BLDC-PM motor drives

DEFF Research Database (Denmark)

Iepure, Liviu Ioan; Boldea, Ion; Blaabjerg, Frede

2012-01-01

A motion sensorless control for single-phase permanent magnet brushless dc motor based on an I-f starting sequence and a real-time permanent magnet flux estimation is proposed here. The special calculation for extracting the position and speed used here implies the generating of an orthogonal flux...... system, the atan2 trigonometric function, and a phase-locked loop observer. The influence of the permanent magnet flux harmonic content is presented by analytical expressions and digital simulations. The proposed sensorless control is validated by complete experimental results on a commercial small high......-speed blower-motor (40 W, 10 krpm, 12 Vdc)....

Variable speed control in wells turbine-based oscillating water column devices: optimum rotational speed

Science.gov (United States)

Lekube, J.; Garrido, A. J.; Garrido, I.

2018-03-01

The effects of climate change and global warming reveal the need to find alternative sources of clean energy. In this sense, wave energy power plants, and in particular Oscillating Water Column (OWC) devices, offer a huge potential of energy harnessing. Nevertheless, the conversion systems have not reached a commercially mature stage yet so as to compete with conventional power plants. At this point, the use of new control methods over the existing technology arises as a doable way to improve the efficiency of the system. Due to the non-uniform response that the turbine shows to the rotational speed variation, the speed control of the turbo-generator may offer a feasible solution for efficiency improvement during the energy conversion. In this context, a novel speed control approach for OWC systems is presented in this paper, demonstrating its goodness and affording promising results when particularized to the Mutriku’s wave power plant.

LOFT PSMG Speed Control System frequency response analysis

International Nuclear Information System (INIS)

Hansen, H.R.

1977-01-01

An analysis was done to gain insight into the shape of the open loop frequency response of the PSMG Speed Control System. The results of the analysis were used as a guide to groom the proportional band and reset time settings of the 2 mode controller in the speed control system. The analysis shows that when an actuator with a timing of 90 degrees per 60 seconds is installed in the system the proportional band and reset time should be 316% and 1 minute. Whereas when grooming the system a proportional band and reset time of 150% and 1.5 minutes were found to be appropriate. The closeness of the settings show that even though a linear model was used to describe the non-linear PSMG Speed Control System, it was accurate enough to be used as a guide to groom the proportional band and reset time settings

Nonlinear Output Feedback Control of Underwater Vehicle Propellers using Advance Speed Feedback

DEFF Research Database (Denmark)

Fossen, T.I.; Blanke, M.

1999-01-01

More accurate propeller shaft speed controllers can be designed by using nonlinear control theory. In this paper, an output feedback controller reconstructing the advance speed (speed of water going into the propeller) from vehicle speed measurements is derived. For this purpose a three-state model...... minimizes thruster losses due to variations in propeller axial inlet flow which is a major problem when applying conventional vehicle-propeller control systems. The proposed controller is simulated for an underwater vehicle equipped with a single propeller. From the simulations it can be concluded...... of propeller shaft speed, forward (surge) speed of the vehicle and axial inlet flow of the propeller is applied. A nonlinear observer in combination with an output feedback integral controller are derived by applying Lyapunov stability theory and exponential stability is proven. The output feedback controller...

Analysis, control and design of speed control of electric vehicles delayed model

DEFF Research Database (Denmark)

Khooban, Mohammad-Hassan; ShaSadeghi, Mokhtar; Niknam, Taher

2017-01-01

The purpose of this study is to suggest an optimal multi-objective fuzzy fractional-order PIλDμPIλDμ controller (MOFFOPID) for the speed control of EV systems with time-delay. It is presumed that while the EV is in movement, the armature winding resistance of the direct current (DC) motor varies...... controller. Finally, the experimental results based on a TMS320F28335 DSP are implemented on a DC motor to verify the effectiveness of the proposed MOFFOPID controller in controlling the speed of the DC motor which has non-linear features. The results of the simulation confirm the desirable performance...

Neuro-Fuzzy DC Motor Speed Control Using Particle Swarm Optimization

Directory of Open Access Journals (Sweden)

Boumediene ALLAOUA

2009-12-01

Full Text Available This paper presents an application of Adaptive Neuro-Fuzzy Inference System (ANFIS control for DC motor speed optimized with swarm collective intelligence. First, the controller is designed according to Fuzzy rules such that the systems are fundamentally robust. Secondly, an adaptive Neuro-Fuzzy controller of the DC motor speed is then designed and simulated; the ANFIS has the advantage of expert knowledge of the Fuzzy inference system and the learning capability of neural networks. Finally, the ANFIS is optimized by Swarm Intelligence. Digital simulation results demonstrate that the deigned ANFIS-Swarm speed controller realize a good dynamic behavior of the DC motor, a perfect speed tracking with no overshoot, give better performance and high robustness than those obtained by the ANFIS alone.

Implementation of Close Loop Speed Control with VVVF Control and Slip Regulation on LIM

Directory of Open Access Journals (Sweden)

K. Aditya

2014-04-01

Full Text Available Open loop VVVF control has the disadvantage of low output torque when working at low frequency and poor speed precision at different load conditions.Various performance-improving schemes have been proposed for the basic VVVF control by compensating slips occurring in the low frequency range and slips caused by changing loads. Numerous papers have been published on the close loop speed control of rotary induction motor. In this paper a close loop speed control with VVVF control and slip regulation has been implemented for LIM based conveyor belt test Rig which compensates the disadvantages of traditional Volts/Hz control. SIMULINK results are presented to validate the effectiveness of proposed scheme.

Real Time Implementation of a DC Motor Speed Control by Fuzzy Logic Controller and PI Controller Using FPGA

Directory of Open Access Journals (Sweden)

G. Sakthivel

2010-10-01

Full Text Available Fuzzy logic control has met with growing interest in many motor control applications due to its non-linearity, handling features and independence of plant modelling. The hardware implementation of fuzzy logic controller (FLC on FPGA is very important because of the increasing number of fuzzy applications requiring highly parallel and high speed fuzzy processing. Implementation of a fuzzy logic controller and conventional PI controller on an FPGA using VHDL for DC motor speed control is presented in this paper. The proposed scheme is to improve tracking performance of D.C. motor as compared to the conventional (PI control strategy .This paper describes the hardware implementation of two inputs (error and change in error, one output fuzzy logic controller based on PI controller and conventional PI controller using VHDL. Real time implementation FLC and conventional PI controller is made on Spartan-3A DSP FPGA (XC3SD1800A FPGA for the speed control of DC motor. It is observed that fuzzy logic based controllers give better responses than the conventional PI controller for the speed control of dc motor.

Fuzzy adaptive speed control of a permanent magnet synchronous motor

Science.gov (United States)

Choi, Han Ho; Jung, Jin-Woo; Kim, Rae-Young

2012-05-01

A fuzzy adaptive speed controller is proposed for a permanent magnet synchronous motor (PMSM). The proposed fuzzy adaptive speed regulator is insensitive to model parameter and load torque variations because it does not need any accurate knowledge about the motor parameter and load torque values. The stability of the proposed control system is also proven. The proposed adaptive speed regulator system is implemented by using a TMS320F28335 floating point DSP. Simulation and experimental results are presented to verify the effectiveness of the proposed fuzzy adaptive speed controller under uncertainties such as motor parameter and load torque variations using a prototype PMSM drive system.

Transient analysis of variable-speed wind turbines at wind speed disturbances and a pitch control malfunction

International Nuclear Information System (INIS)

Melicio, R.; Mendes, V.M.F.; Catalao, J.P.S.

2011-01-01

As wind power generation undergoes rapid growth, new technical challenges emerge: dynamic stability and power quality. The influence of wind speed disturbances and a pitch control malfunction on the quality of the energy injected into the electric grid is studied for variable-speed wind turbines with different power-electronic converter topologies. Additionally, a new control strategy is proposed for the variable-speed operation of wind turbines with permanent magnet synchronous generators. The performance of disturbance attenuation and system robustness is ascertained. Simulation results are presented and conclusions are duly drawn.

Transient analysis of variable-speed wind turbines at wind speed disturbances and a pitch control malfunction

Energy Technology Data Exchange (ETDEWEB)

Melicio, R. [Department of Electromechanical Engineering, University of Beira Interior, R. Fonte do Lameiro, 6201-001 Covilha (Portugal); Mendes, V.M.F. [Department of Electrical Engineering and Automation, Instituto Superior de Engenharia de Lisboa, R. Conselheiro Emidio Navarro, 1950-062 Lisbon (Portugal); Catalao, J.P.S. [Department of Electromechanical Engineering, University of Beira Interior, R. Fonte do Lameiro, 6201-001 Covilha (Portugal); Center for Innovation in Electrical and Energy Engineering, Instituto Superior Tecnico, Technical University of Lisbon, Av. Rovisco Pais, 1049-001 Lisbon (Portugal)

2011-04-15

As wind power generation undergoes rapid growth, new technical challenges emerge: dynamic stability and power quality. The influence of wind speed disturbances and a pitch control malfunction on the quality of the energy injected into the electric grid is studied for variable-speed wind turbines with different power-electronic converter topologies. Additionally, a new control strategy is proposed for the variable-speed operation of wind turbines with permanent magnet synchronous generators. The performance of disturbance attenuation and system robustness is ascertained. Simulation results are presented and conclusions are duly drawn. (author)

Digitally controlled analog proportional-integral-derivative (PID) controller for high-speed scanning probe microscopy

Science.gov (United States)

Dukic, Maja; Todorov, Vencislav; Andany, Santiago; Nievergelt, Adrian P.; Yang, Chen; Hosseini, Nahid; Fantner, Georg E.

2017-12-01

Nearly all scanning probe microscopes (SPMs) contain a feedback controller, which is used to move the scanner in the direction of the z-axis in order to maintain a constant setpoint based on the tip-sample interaction. The most frequently used feedback controller in SPMs is the proportional-integral (PI) controller. The bandwidth of the PI controller presents one of the speed limiting factors in high-speed SPMs, where higher bandwidths enable faster scanning speeds and higher imaging resolution. Most SPM systems use digital signal processor-based PI feedback controllers, which require analog-to-digital and digital-to-analog converters. These converters introduce additional feedback delays which limit the achievable imaging speed and resolution. In this paper, we present a digitally controlled analog proportional-integral-derivative (PID) controller. The controller implementation allows tunability of the PID gains over a large amplification and frequency range, while also providing precise control of the system and reproducibility of the gain parameters. By using the analog PID controller, we were able to perform successful atomic force microscopy imaging of a standard silicon calibration grating at line rates up to several kHz.

MAINTAINING VEHICLE SPEED USING A MECHANICAL CRUISE CONTROL

Directory of Open Access Journals (Sweden)

Peter GIROVSKÝ

2017-06-01

Full Text Available In this article we would like to present cruise control realization. This cruise control is presented as mechanical device for vehicle speed maintenance and has been proposed as a low cost solution. Principle of function in mechanical cruise control is based on a position control of throttle. For the right action of mechanical cruise control it was need to solve some particular tasks related with speed sensing, construct of device for control of throttle position and design of control system of whole mechanical cruise control. Information about car velocity we have gained using Hall sensor attached on a magnetic ring of car tachometer. For control of the throttle was used a small servo drive and as the control unit was used Arduino. The designed solution of mechanical cruise control have been realized for car Škoda Felicia.

Automatic Tuning of Control Parameters for Single Speed Engines

OpenAIRE

Olsson, Johan

2004-01-01

In Scania’s single speed engines for industrial and marine use, the engine speed is controlled by a PI-controller. This controller is tuned independent of engine type and application. This brings certain disadvantages since the engines are used in a wide range of applications where the dynamics may differ. In this thesis, the possibility to tune the controller automatically for a specific engine installation has been investigated. The work shows that automatic tuning is possible. By performin...

Experimental Comparison of Speed : Fuel-flow and Speed-area Controls on a Turbojet Engine for Small Step Disturbances

Science.gov (United States)

Wenzel, L M; Hart, C E; Craig, R T

1957-01-01

Optimum proportional-plus-integral control settings for speed - fuel-flow control, determined by minimization of integral criteria, correlated well with analytically predicted optimum settings. Engine response data are given for a range of control settings around the optimum. An inherent nonlinearity in the speed-area loop necessitated the use of nonlinear controls. Response data for two such nonlinear control schemes are presented.

Fractional order PID controller for improvement of PMSM speed control in aerospace applications

Energy Technology Data Exchange (ETDEWEB)

Saraji, Ali Motalebi [Young Researchers and Elite Club, AliAbad Katoul Branch, Islamic Azad University, AliAbad Katoul (Iran, Islamic Republic of); Ghanbari, Mahmood [Department of Electrical Engineering, AliAbad Katoul Branch, Islamic Azad University, AliAbad Katoul (Iran, Islamic Republic of)

2014-12-10

Because of the benefits reduced size, cost and maintenance, noise, CO2 emissions and increased control flexibility and precision, to meet these expectations, electrical equipment increasingly utilize in modern aircraft systems and aerospace industry rather than conventional mechanic, hydraulic, and pneumatic power systems. Electric motor drives are capable of converting electrical power to drive actuators, pumps, compressors, and other subsystems at variable speeds. In the past decades, permanent magnet synchronous motor (PMSM) and brushless dc (BLDC) motor were investigated for aerospace applications such as aircraft actuators. In this paper, the fractional-order PID controller is used in the design of speed loop of PMSM speed control system. Having more parameters for tuning fractional order PID controller lead to good performance ratio to integer order. This good performance is shown by comparison fractional order PID controller with the conventional PI and tuned PID controller by Genetic algorithm in MATLAB soft wear.

Fractional order PID controller for improvement of PMSM speed control in aerospace applications

International Nuclear Information System (INIS)

Saraji, Ali Motalebi; Ghanbari, Mahmood

2014-01-01

Because of the benefits reduced size, cost and maintenance, noise, CO2 emissions and increased control flexibility and precision, to meet these expectations, electrical equipment increasingly utilize in modern aircraft systems and aerospace industry rather than conventional mechanic, hydraulic, and pneumatic power systems. Electric motor drives are capable of converting electrical power to drive actuators, pumps, compressors, and other subsystems at variable speeds. In the past decades, permanent magnet synchronous motor (PMSM) and brushless dc (BLDC) motor were investigated for aerospace applications such as aircraft actuators. In this paper, the fractional-order PID controller is used in the design of speed loop of PMSM speed control system. Having more parameters for tuning fractional order PID controller lead to good performance ratio to integer order. This good performance is shown by comparison fractional order PID controller with the conventional PI and tuned PID controller by Genetic algorithm in MATLAB soft wear

Tip Speed Ratio Based Maximum Power Tracking Control of Variable Speed Wind Turbines; A Comprehensive Design

Directory of Open Access Journals (Sweden)

Murat Karabacak

2017-08-01

Full Text Available The most primitive control method of wind turbines used to generate electric energy from wind is the fixed speed control method. With this method, it is not possible that turbine input power is transferred to grid at maximum rate. For this reason, Maximum Power Tracking (MPT schemes are proposed. In order to implement MPT, the propeller has to rotate at a different speed for every different wind speed. This situation has led MPT based systems to be called Variable Speed Wind Turbine (VSWT systems. In VSWT systems, turbine input power can be transferred to grid at rates close to maximum power. When MPT based control of VSWT systems is the case, two important processes come into prominence. These are instantaneously determination and tracking of MPT point. In this study, using a Maximum Power Point Tracking (MPPT method based on tip speed ratio, power available in wind is transferred into grid over a back to back converter at maximum rate via a VSWT system with permanent magnet synchronous generator (PMSG. Besides a physical wind turbine simulator is modelled and simulated. Results show that a time varying MPPT point is tracked with a high performance.

Method for rudder roll stabilization control by maintaining ship speed

Directory of Open Access Journals (Sweden)

LIU Zhiquan

2017-01-01

Full Text Available A ship navigating on the surface of the water may experience greater resistance, adversely affect-ing its speed and leading to energy loss. The added resistance of surface ships in both still water and waves are investigated, and the computation method of total speed loss is presented. An autopilot system is intro-duced to constrain the speed loss, and course keeping and rudder roll stabilization sliding mode control laws are proposed according to a compact control strategy. The two working conditions of "heading" and "heading plus anti-roll" are discussed, including roll stabilization, heading error, speed maintenance and rudder abrasion. The results show that the speed can be effectively maintained using this method, and from a commercial point of view, the fin-rudder roll stabilization control is not recommended for vessels equipped with both fins and rudders.

Integrated High-Speed Torque Control System for a Robotic Joint

Science.gov (United States)

Davis, Donald R. (Inventor); Radford, Nicolaus A. (Inventor); Permenter, Frank Noble (Inventor); Valvo, Michael C. (Inventor); Askew, R. Scott (Inventor)

2013-01-01

A control system for achieving high-speed torque for a joint of a robot includes a printed circuit board assembly (PCBA) having a collocated joint processor and high-speed communication bus. The PCBA may also include a power inverter module (PIM) and local sensor conditioning electronics (SCE) for processing sensor data from one or more motor position sensors. Torque control of a motor of the joint is provided via the PCBA as a high-speed torque loop. Each joint processor may be embedded within or collocated with the robotic joint being controlled. Collocation of the joint processor, PIM, and high-speed bus may increase noise immunity of the control system, and the localized processing of sensor data from the joint motor at the joint level may minimize bus cabling to and from each control node. The joint processor may include a field programmable gate array (FPGA).

Electric vehicle speed control

Energy Technology Data Exchange (ETDEWEB)

Krueger, W.R.; Mc Auliffe, G.N.; Schlageter, G.A.

1987-06-23

This patent describes an electric vehicle driven by a DC motor. The vehicle has a field winding, an electric resistance element in circuit with the field winding, a switch in the circuit operative when closed to place. The element in parallel with the field winding weakens the field and increases potential motor speed. Also are relay means for operating the switch, means to determine motor speed, computer means for determining whether the motor speed is increasing or decreasing, and means for operating the relay means to close the switch at a first speed. If the motor speed is increased, it actuates the switch at a second speed lower than the first speed but only if switch has been closed previously and motor speed is decreasing.

A Comparison Study between Two MPPT Control Methods for a Large Variable-Speed Wind Turbine under Different Wind Speed Characteristics

Directory of Open Access Journals (Sweden)

Dongran Song

2017-05-01

Full Text Available Variable speed wind turbines (VSWTs usually adopt a maximum power point tracking (MPPT method to optimize energy capture performance. Nevertheless, obtained performance offered by different MPPT methods may be affected by the impact of wind turbine (WT’s inertia and wind speed characteristics and it needs to be clarified. In this paper, the tip speed ratio (TSR and optimal torque (OT methods are investigated in terms of their performance under different wind speed characteristics on a 1.5 MW wind turbine model. To this end, the TSR control method based on an effective wind speed estimator and the OT control method are firstly presented. Then, their performance is investigated and compared through simulation test results under different wind speeds using Bladed software. Comparison results show that the TSR control method can capture slightly more wind energy at the cost of high component loads than the other one under all wind conditions. Furthermore, it is found that both control methods present similar trends of power reduction that is relevant to mean wind speed and turbulence intensity. From the obtained results, we demonstrate that, to further improve MPPT capability of large VSWTs, other advanced control methods using wind speed prediction information need to be addressed.

Pitch Motion Stabilization by Propeller Speed Control Using Statistical Controller Design

DEFF Research Database (Denmark)

Nakatani, Toshihiko; Blanke, Mogens; Galeazzi, Roberto

2006-01-01

This paper describes dynamics analysis of a small training boat and a possibility of ship pitch stabilization by control of propeller speed. After upgrading the navigational system of an actual small training boat, in order to identify the model of the ship, the real data collected by sea trials...... were used for statistical analysis and system identification. This analysis shows that the pitching motion is indeed influenced by engine speed and it is suggested that there exists a possibility of reducing the pitching motion by properly controlling the engine throttle. Based on this observation...

Pneumatic motor speed control by trajectory tracking fuzzy logic

Indian Academy of Sciences (India)

In this study, trajectory tracking fuzzy logic controller (TTFLC) is proposed for the speed control of a pneumatic motor (PM). A third order trajectory is defined to determine the trajectory function that has to be tracked by the PM speed. Genetic algorithm (GA) is used to find the TTFLC boundary values of membership functions ...

Two-Phase Induction Motor Drives

Directory of Open Access Journals (Sweden)

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.

Extending the Constant Power Speed Range of the Brushless DC Motor through Dual Mode Inverter Control -- Part I: Theory and Simulation

International Nuclear Information System (INIS)

Lawler, J.S.

2001-01-01

An inverter topology and control scheme has been developed that can drive low-inductance, surface-mounted permanent magnet motors over the wide constant power speed range required in electric vehicle applications. This new controller is called the dual-mode inverter control (DMIC)[1]. The DMIC can drive either the Permanent Magnet Synchronous Machine (PMSM) with sinusoidal back emf, or the brushless dc machine (BDCM) with trapezoidal emf in the motoring and regenerative braking modes. In this paper we concentrate on the BDCM under high-speed motoring conditions. Simulation results show that if all motor and inverter loss mechanisms are neglected, the constant power speed range of the DMIC is infinite. The simulation results are supported by closed form expressions for peak and rms motor current and average power derived from analytical solution to the differential equations governing the DMIC/BDCM drive for the lossless case. The analytical solution shows that the range of motor inductance that can be accommodated by the DMIC is more than an order of magnitude such that the DMIC is compatible with both low- and high-inductance BDCMs. Finally, method is given for integrating the classical hysteresis band current control, used for motor control below base speed, with the phase advance of DMIC that is applied above base speed. The power versus speed performance of the DMIC is then simulated across the entire speed range

Prefrontal, posterior parietal and sensorimotor network activity underlying speed control during walking

Directory of Open Access Journals (Sweden)

Thomas C Bulea

2015-05-01

Full Text Available Accumulating evidence suggests cortical circuits may contribute to control of human locomotion. Here, noninvasive electroencephalography (EEG recorded from able-bodied volunteers during a novel treadmill walking paradigm was used to assess neural correlates of walking. A systematic processing method, including a recently developed subspace reconstruction algorithm, reduced movement-related EEG artifact prior to independent component analysis and dipole source localization. We quantified cortical activity while participants tracked slow and fast target speeds across two treadmill conditions: an active mode that adjusted belt speed based on user movements and a passive mode reflecting a typical treadmill. Our results reveal frequency specific, multi-focal task related changes in cortical oscillations elicited by active walking. Low γ band power, localized to the prefrontal and posterior parietal cortices, was significantly increased during double support and early swing phases, critical points in the gait cycle since the active controller adjusted speed based on pelvis position and swing foot velocity. These phasic γ band synchronizations provide evidence that prefrontal and posterior parietal networks, previously implicated in visuo-spatial and somotosensory integration, are engaged to enhance lower limb control during gait. Sustained μ and β band desynchronization within sensorimotor cortex, a neural correlate for movement, was observed during walking thereby validating our methods for isolating cortical activity. Our results also demonstrate the utility of EEG recorded during locomotion for probing the multi-regional cortical networks which underpin its execution. For example, the cortical network engagement elicited by the active treadmill suggests that it may enhance neuroplasticity for more effective motor training.

Robust Adaptive Speed Control of Induction Motor Drives

DEFF Research Database (Denmark)

Bidstrup, N.

, (LS) identification and generalized predictive control (GPC) has been implemented and tested on the CVC drive. Allthough GPC is a robust control method, it was not possible to maintain specified controller performance in the entire operating range. This was the main reason for investigating truly...... adaptive speed control of the CVC drive. A direct truly adaptive speed controller has been implemented. The adaptive controller is a moving Average Self-Tuning Regulator which is abbreviated MASTR throughout the thesis. Two practical implementations of this controller were proposed. They were denoted MASTR...... and measurement noise in general, were the major reasons for the drifting parameters. Two approaches was proposed to robustify MASTR2 against the output noise. The first approach consists of filtering the output. Output filtering had a significant effect in simulations, but the robustness against the output noise...

An RFID-Based Intelligent Vehicle Speed Controller Using Active Traffic Signals

Directory of Open Access Journals (Sweden)

Joshué Pérez

2010-06-01

Full Text Available These days, mass-produced vehicles benefit from research on Intelligent Transportation System (ITS. One prime example of ITS is vehicle Cruise Control (CC, which allows it to maintain a pre-defined reference speed, to economize on fuel or energy consumption, to avoid speeding fines, or to focus all of the driver’s attention on the steering of the vehicle. However, achieving efficient Cruise Control is not easy in roads or urban streets where sudden changes of the speed limit can happen, due to the presence of unexpected obstacles or maintenance work, causing, in inattentive drivers, traffic accidents. In this communication we present a new Infrastructure to Vehicles (I2V communication and control system for intelligent speed control, which is based upon Radio Frequency Identification (RFID technology for identification of traffic signals on the road, and high accuracy vehicle speed measurement with a Hall effect-based sensor. A fuzzy logic controller, based on sensor fusion of the information provided by the I2V infrastructure, allows the efficient adaptation of the speed of the vehicle to the circumstances of the road. The performance of the system is checked empirically, with promising results.

An RFID-Based Intelligent Vehicle Speed Controller Using Active Traffic Signals

Science.gov (United States)

Pérez, Joshué; Seco, Fernando; Milanés, Vicente; Jiménez, Antonio; Díaz, Julio C.; de Pedro, Teresa

2010-01-01

These days, mass-produced vehicles benefit from research on Intelligent Transportation System (ITS). One prime example of ITS is vehicle Cruise Control (CC), which allows it to maintain a pre-defined reference speed, to economize on fuel or energy consumption, to avoid speeding fines, or to focus all of the driver’s attention on the steering of the vehicle. However, achieving efficient Cruise Control is not easy in roads or urban streets where sudden changes of the speed limit can happen, due to the presence of unexpected obstacles or maintenance work, causing, in inattentive drivers, traffic accidents. In this communication we present a new Infrastructure to Vehicles (I2V) communication and control system for intelligent speed control, which is based upon Radio Frequency Identification (RFID) technology for identification of traffic signals on the road, and high accuracy vehicle speed measurement with a Hall effect-based sensor. A fuzzy logic controller, based on sensor fusion of the information provided by the I2V infrastructure, allows the efficient adaptation of the speed of the vehicle to the circumstances of the road. The performance of the system is checked empirically, with promising results. PMID:22219692

An RFID-based intelligent vehicle speed controller using active traffic signals.

Science.gov (United States)

Pérez, Joshué; Seco, Fernando; Milanés, Vicente; Jiménez, Antonio; Díaz, Julio C; de Pedro, Teresa

2010-01-01

These days, mass-produced vehicles benefit from research on Intelligent Transportation System (ITS). One prime example of ITS is vehicle Cruise Control (CC), which allows it to maintain a pre-defined reference speed, to economize on fuel or energy consumption, to avoid speeding fines, or to focus all of the driver's attention on the steering of the vehicle. However, achieving efficient Cruise Control is not easy in roads or urban streets where sudden changes of the speed limit can happen, due to the presence of unexpected obstacles or maintenance work, causing, in inattentive drivers, traffic accidents. In this communication we present a new Infrastructure to Vehicles (I2V) communication and control system for intelligent speed control, which is based upon Radio Frequency Identification (RFID) technology for identification of traffic signals on the road, and high accuracy vehicle speed measurement with a Hall effect-based sensor. A fuzzy logic controller, based on sensor fusion of the information provided by the I2V infrastructure, allows the efficient adaptation of the speed of the vehicle to the circumstances of the road. The performance of the system is checked empirically, with promising results.

Speed Synchronization of Multi Induction Motors with Fuzzy Sliding Mode Control

Directory of Open Access Journals (Sweden)

HACHEMI Glaoui

2013-05-01

Full Text Available A continuous web winding system is a large-scale, complex interconnected dynamic system with numerous tension zones to transport the web while processing it. There are two control schemes for large-scale system control: the centralized scheme and the decentralized scheme. Centralized control is the traditional control method, which considers all the information about the system to be a single dynamic model and design a control system for this model. Aspeed synchronization control strategy for multiple induction motors, based on adjacent cross-coupling control structure, is developed by employing total sliding mode control method. The proposed controlstrategy is to stabilize speed tracking of each induction motor while synchronizing its speed with the speed of the other motors so as to make speed synchronization error amongst induction motors converge to zero. The global stability and the convergence of the designedcontroller are proved by using Lyapunov method. Simulation results demonstrate the effectiveness of the proposed method.

Intelligent control for large-scale variable speed variable pitch wind turbines

Institute of Scientific and Technical Information of China (English)

Xinfang ZHANG; Daping XU; Yibing LIU

2004-01-01

Large-scale wind turbine generator systems have strong nonlinear multivariable characteristics with many uncertain factors and disturbances.Automatic control is crucial for the efficiency and reliability of wind turbines.On the basis of simplified and proper model of variable speed variable pitch wind turbines,the effective wind speed is estimated using extended Kalman filter.Intelligent control schemes proposed in the paper include two loops which operate in synchronism with each other.At below-rated wind speed,the inner loop adopts adaptive fuzzy control based on variable universe for generator torque regulation to realize maximum wind energy capture.At above-rated wind speed, a controller based on least square support vector machine is proposed to adjust pitch angle and keep rated output power.The simulation shows the effectiveness of the intelligent control.

Vehicle speed control using road bumps

Directory of Open Access Journals (Sweden)

T. A. O. Salau

2004-06-01

Full Text Available Road bumps play a crucial role in enforcing speed limits, thereby preventing overspeeding of vehicles. It significantly contributes to the overall road safety objective through the prevention of accidents that lead to deaths of pedestrians and damage of vehicles. Despite the importance of road bumps, very little research has been done to investigate into their design. While documentation exists on quantitative descriptions of road bumps, they offer little guidance to decision making. This work presents a unique approach to solving road bumps design problems. The results of our study reveal three important road bumps variables that influence the control of vehicle speeds. The key variables are bump height, bump width, and effective distance between two consecutive road bumps. Since vehicle speed control is the ultimate aim of this study the relationship between vehicle speed and other variables earlier mentioned is established. Vehicle speed is defined as the product of frequency at which a vehicle is moving over road bumps and the sum of effective distance between two consecutive road bumps. In the determination of bump height we assume a conical shaped curve for analysis as a matter of research strategy. Based on this, two stages of motion were analysed. The first concerns the motion over the bump itself while the second relates to the motion between two consecutive road bumps. Fourier series was then used to formulate a holistic equation that combines these two stages. We used trigonometric functions to model the behaviour of the first stage while with the second stage giving a functional value of zero since no changes in height are observed. We carried out vibration analysis to determine the effect of road bumps on a vehicular system. Arising from this a model component is referred to as an isolation factor. This offers guidance to the safe frequency at which vehicles could travel over road bumps. The work appears to contribute to knowledge

Modified Euler integration based control of a five-phase induction ...

African Journals Online (AJOL)

phase machines. Variable speed induction motor drives without mechanical speed sensors at the motor shaft have the attractions of low cost and high reliability. To replace the speed sensor, information of the rotor speed is extracted from ...

Comprehensive analysis of the carbon impacts of vehicle intelligent speed control

Science.gov (United States)

Carslaw, David C.; Goodman, Paul S.; Lai, Frank C. H.; Carsten, Oliver M. J.

2010-07-01

In recent years sophisticated technologies have been developed to control vehicle speed based on the type of road the vehicle is driven on using Global Positioning Systems and in-car technology that can alter the speed of the vehicle. While reducing the speed of road vehicles is primarily of interest from a safety perspective, vehicle speed is also an important determinant of vehicle emissions and thus these technologies can be expected to have impacts on a range of exhaust emissions. This work analyses the results from a very large, comprehensive field trial that used 20 instrumented vehicles with and without speed control driven almost 500,000 km measuring vehicle speed at 10 Hz. We develop individual vehicle modal emissions models for CO 2 for 30 Euro III and Euro IV cars at a 1-Hz time resolution. Generalized Additive Models were used to describe how emissions from individual vehicles vary depending on their driving conditions, taking account of variable interactions and time-lag effects. We quantify the impact that vehicle speed control has on-vehicle emissions of CO 2 by road type, fuel type and driver behaviour. Savings in CO 2 of ≈6% were found on average for motorway-type roads when mandatory speed control was used compared with base case conditions. For most other types of road, speed control has very little effect on emissions of CO 2 and in some cases can result in increased emissions for low-speed limit urban roads. We also find that there is on average a 20% difference in CO 2 emission between the lowest and highest emitting driver, which highlights the importance of driver behaviour in general as a means of reducing emissions of CO 2.

Simulation model of an active-stall fixed-speed wind turbine controller

Energy Technology Data Exchange (ETDEWEB)

Jauch, C.; Hansen, A.D.; Sorensen, P.; Blaabjerg, F.

2004-07-01

This paper describes an active-stall wind turbine controller. The objective is to develop a general model of an active stall controller in order to simulate the operation of grid connected active stall wind turbines. The active stall turbine concept and its control strategies are presented and evaluated by simulations. The presented controller is described for continuous operation under all wind speeds from start-up wind speed to shut down wind speed. Due to its parametric implementation it is general i. e. it can represent different active stall wind turbine controllers and can be implemented in different simulation tools. (author)

Green operations of belt conveyors by means of speed control

NARCIS (Netherlands)

He, D.; Pang, Y.; Lodewijks, G.

2017-01-01

Belt conveyors can be partially loaded due to the variation of bulk material flow loaded onto the conveyor. Speed control attempts to reduce the belt conveyor energy consumption and to enable the green operations of belt conveyors. Current research of speed control rarely takes the conveyor dynamics

UDE-based control of variable-speed wind turbine systems

Science.gov (United States)

Ren, Beibei; Wang, Yeqin; Zhong, Qing-Chang

2017-01-01

In this paper, the control of a PMSG (permanent magnet synchronous generator)-based variable-speed wind turbine system with a back-to-back converter is considered. The uncertainty and disturbance estimator (UDE)-based control approach is applied to the regulation of the DC-link voltage and the control of the RSC (rotor-side converter) and the GSC (grid-side converter). For the rotor-side controller, the UDE-based vector control is developed for the RSC with PMSG control to facilitate the application of the MPPT (maximum power point tracking) algorithm for the maximum wind energy capture. For the grid-side controller, the UDE-based vector control is developed to control the GSC with the power reference generated by a UDE-based DC-link voltage controller. Compared with the conventional vector control, the UDE-based vector control can achieve reliable current decoupling control with fast response. Moreover, the UDE-based DC-link voltage regulation can achieve stable DC-link voltage under model uncertainties and external disturbances, e.g. wind speed variations. The effectiveness of the proposed UDE-based control approach is demonstrated through extensive simulation studies in the presence of coupled dynamics, model uncertainties and external disturbances under varying wind speeds. The UDE-based control is able to generate more energy, e.g. by 5% for the wind profile tested.

Differences in hamstring activation characteristics between the acceleration and maximum-speed phases of sprinting.

Science.gov (United States)

Higashihara, Ayako; Nagano, Yasuharu; Ono, Takashi; Fukubayashi, Toru

2018-06-01

This study aimed to investigate activation characteristics of the biceps femoris long head (BFlh) and semitendinosus (ST) muscles during the acceleration and maximum-speed phases of sprinting. Lower-extremity kinematics and electromyographic (EMG) activities of the BFlh and ST muscles were examined during the acceleration sprint and maximum-speed sprint in 13 male sprinters during an overground sprinting. Differences in hamstring activation during each divided phases and in the hip and knee joint angles and torques at each time point of the sprinting gait cycle were determined between two sprints. During the early stance of the acceleration sprint, the hip extension torque was significantly greater than during the maximum-speed sprint, and the relative EMG activation of the BFlh muscle was significantly higher than that of the ST muscle. During the late stance and terminal mid-swing of maximum-speed sprint, the knee was more extended and a higher knee flexion moment was observed compared to the acceleration sprint, and the ST muscle showed higher activation than that of the BFlh. These results indicate that the functional demands of the medial and lateral hamstring muscles differ between two different sprint performances.

Improved Rotor Speed Brushless DC Motor Using Fuzzy Controller

Directory of Open Access Journals (Sweden)

Jafar Mostafapour

2015-04-01

Full Text Available A brushless DC (BLDC Motors have advantages over brushed, Direct current (DC Motors and , Induction motor (IM. They have better speed verses torque characteristics, high dynamic response, high efficiency, long operating life, noiseless operation, higher speed ranges, and rugged construction. Also, torque delivered to motor size is higher, making it useful in application where space and weight are critical factors. With these advantages BLDC motors find wide spread application in automotive appliance, aerospace medical, and instrumentation and automation industries This paper can be seen as fuzzy controllers compared to PI control BLDC motor rotor speed has improved significantly and beter result can be achieve.

Predicting a new phase (T'') of two-dimensional transition metal di-chalcogenides and strain-controlled topological phase transition

Science.gov (United States)

Ma, Fengxian; Gao, Guoping; Jiao, Yalong; Gu, Yuantong; Bilic, Ante; Zhang, Haijun; Chen, Zhongfang; Du, Aijun

2016-02-01

Single layered transition metal dichalcogenides have attracted tremendous research interest due to their structural phase diversities. By using a global optimization approach, we have discovered a new phase of transition metal dichalcogenides (labelled as T''), which is confirmed to be energetically, dynamically and kinetically stable by our first-principles calculations. The new T'' MoS2 phase exhibits an intrinsic quantum spin Hall (QSH) effect with a nontrivial gap as large as 0.42 eV, suggesting that a two-dimensional (2D) topological insulator can be achieved at room temperature. Most interestingly, there is a topological phase transition simply driven by a small tensile strain of up to 2%. Furthermore, all the known MX2 (M = Mo or W; X = S, Se or Te) monolayers in the new T'' phase unambiguously display similar band topologies and strain controlled topological phase transitions. Our findings greatly enrich the 2D families of transition metal dichalcogenides and offer a feasible way to control the electronic states of 2D topological insulators for the fabrication of high-speed spintronics devices.Single layered transition metal dichalcogenides have attracted tremendous research interest due to their structural phase diversities. By using a global optimization approach, we have discovered a new phase of transition metal dichalcogenides (labelled as T''), which is confirmed to be energetically, dynamically and kinetically stable by our first-principles calculations. The new T'' MoS2 phase exhibits an intrinsic quantum spin Hall (QSH) effect with a nontrivial gap as large as 0.42 eV, suggesting that a two-dimensional (2D) topological insulator can be achieved at room temperature. Most interestingly, there is a topological phase transition simply driven by a small tensile strain of up to 2%. Furthermore, all the known MX2 (M = Mo or W; X = S, Se or Te) monolayers in the new T'' phase unambiguously display similar band topologies and strain controlled topological

Using Variable Speed Control on Pump Application

Directory of Open Access Journals (Sweden)

Dr.Sc. Aida Spahiu

2012-06-01

Full Text Available Pumps are one of the most common variable speed drive (VSD system applications and special interest has focused on improving their energy efficiency by using variable speed control instead of throttling or other less efficient flow control methods. Pumps are the single largest user of electricity in industry in the European Union, consuming 160 TWh per annum of electricity and accounting for 79 million tonnes of carbon dioxide (CO2 emissions [1]. Centrifugal pumps are the most likely pump style to provide a favorable return based on energy savings when applied with a variable speed drive. To help illustrate this, are conducted benchmark testing to document various head and flow scenarios and their corresponding effect on energy savings. Paper shows the relationship of static and friction head in the energy efficiency equation and the effect of motor, pump and VSD efficiencies. The received results are good reference points for engineers and managers of water sector in Albania to select the best prospects for maximizing efficiency and energy savings.

Bi Input-extended Kalman filter based estimation technique for speed-sensorless control of induction motors

International Nuclear Information System (INIS)

Barut, Murat

2010-01-01

This study offers a novel extended Kalman filter (EKF) based estimation technique for the solution of the on-line estimation problem related to uncertainties in the stator and rotor resistances inherent to the speed-sensorless high efficiency control of induction motors (IMs) in the wide speed range as well as extending the limited number of states and parameter estimations possible with a conventional single EKF algorithm. For this aim, the introduced estimation technique in this work utilizes a single EKF algorithm with the consecutive execution of two inputs derived from the two individual extended IM models based on the stator resistance and rotor resistance estimation, differently from the other approaches in past studies, which require two separate EKF algorithms operating in a switching or braided manner; thus, it has superiority over the previous EKF schemes in this regard. The proposed EKF based estimation technique performing the on-line estimations of the stator currents, the rotor flux, the rotor angular velocity, and the load torque involving the viscous friction term together with the rotor and stator resistance is also used in the combination with the speed-sensorless direct vector control of IM and tested with simulations under the challenging 12 scenarios generated instantaneously via step and/or linear variations of the velocity reference, the load torque, the stator resistance, and the rotor resistance in the range of high and zero speed, assuming that the measured stator phase currents and voltages are available. Even under those variations, the performance of the speed-sensorless direct vector control system established on the novel EKF based estimation technique is observed to be quite good.

Bi Input-extended Kalman filter based estimation technique for speed-sensorless control of induction motors

Energy Technology Data Exchange (ETDEWEB)

Barut, Murat, E-mail: muratbarut27@yahoo.co [Nigde University, Department of Electrical and Electronics Engineering, 51245 Nigde (Turkey)

2010-10-15

This study offers a novel extended Kalman filter (EKF) based estimation technique for the solution of the on-line estimation problem related to uncertainties in the stator and rotor resistances inherent to the speed-sensorless high efficiency control of induction motors (IMs) in the wide speed range as well as extending the limited number of states and parameter estimations possible with a conventional single EKF algorithm. For this aim, the introduced estimation technique in this work utilizes a single EKF algorithm with the consecutive execution of two inputs derived from the two individual extended IM models based on the stator resistance and rotor resistance estimation, differently from the other approaches in past studies, which require two separate EKF algorithms operating in a switching or braided manner; thus, it has superiority over the previous EKF schemes in this regard. The proposed EKF based estimation technique performing the on-line estimations of the stator currents, the rotor flux, the rotor angular velocity, and the load torque involving the viscous friction term together with the rotor and stator resistance is also used in the combination with the speed-sensorless direct vector control of IM and tested with simulations under the challenging 12 scenarios generated instantaneously via step and/or linear variations of the velocity reference, the load torque, the stator resistance, and the rotor resistance in the range of high and zero speed, assuming that the measured stator phase currents and voltages are available. Even under those variations, the performance of the speed-sensorless direct vector control system established on the novel EKF based estimation technique is observed to be quite good.

Simultaneous thermal stability and phase change speed improvement of Sn15Sb85 thin film through erbium doping

Science.gov (United States)

Zou, Hua; Zhu, Xiaoqin; Hu, Yifeng; Sui, Yongxing; Sun, Yuemei; Zhang, Jianhao; Zheng, Long; Song, Zhitang

2016-12-01

In general, there is a trade off between the phase change speed and thermal stability in chalcogenide phase change materials, which leads to sacrifice the one in order to ensure the other. For improving the performance, doping is a widely applied technological process. Here, we fabricated Er doped Sn15Sb85 thin films by magnetron sputtering. Compared with the pure Sn15Sb85, we show that Er doped Sn15Sb85 thin films exhibit simultaneous improvement over the thermal stability and the phase change speed. Thus, our results suggest that Er doping provides the opportunity to solve the contradiction. The main reason for improvement of both thermal stability and crystallization speed is due to the existence of Er-Sb and Er-Sn bonds in Er doped Sn15Sb85 films. Hence, Er doped Sn15Sb85 thin films are promising candidates for the phase change memory application, and this method could be extended to other lanthanide-doped phase change materials.

Controlling the Dc-link Midpoint Potential in a Six-phase Motor-drive

DEFF Research Database (Denmark)

Bendixen, Flemming Buus; Blaabjerg, Frede; Rasmussen, Peter Omand

2004-01-01

inverter branch and filter inductances is needed for stabilizing the midpoint potential of the series connected dc-capacitor link. A new control strategy that pre-calculates the allowed voltage ripple and controls the motor voltage accordingly (using two standard three phase inverter modules) is suggested....... With this new control strategy the seventh branch and an inductance can be saved. It also opens the possibility to use two standard three-phase inverters to supply the six-phase motor. An experimental setup is build and the theory is verified in the test case. The proposed control strategy works satisfactory....... A drawback is that the voltage ripple in the midpoint increases, if a third harmonic current is injected specially at low speed, which could demand a higher voltage rating of the capacitors. Another drawback is that the higher voltage ripple will stress the capacitors hence the lifetime may be shortened....

The research of automatic speed control algorithm based on Green CBTC

Science.gov (United States)

Lin, Ying; Xiong, Hui; Wang, Xiaoliang; Wu, Youyou; Zhang, Chuanqi

2017-06-01

Automatic speed control algorithm is one of the core technologies of train operation control system. It’s a typical multi-objective optimization control algorithm, which achieve the train speed control for timing, comfort, energy-saving and precise parking. At present, the train speed automatic control technology is widely used in metro and inter-city railways. It has been found that the automatic speed control technology can effectively reduce the driver’s intensity, and improve the operation quality. However, the current used algorithm is poor at energy-saving, even not as good as manual driving. In order to solve the problem of energy-saving, this paper proposes an automatic speed control algorithm based on Green CBTC system. Based on the Green CBTC system, the algorithm can adjust the operation status of the train to improve the efficient using rate of regenerative braking feedback energy while ensuring the timing, comfort and precise parking targets. Due to the reason, the energy-using of Green CBTC system is lower than traditional CBTC system. The simulation results show that the algorithm based on Green CBTC system can effectively reduce the energy-using due to the improvement of the using rate of regenerative braking feedback energy.

Analysis and MPPT control of a wind-driven three-phase induction generator feeding single-phase utility grid

Directory of Open Access Journals (Sweden)

Krishnan Arthishri

2017-05-01

Full Text Available In this study, a three-phase diode bridge rectifier and a single-phase voltage source inverter topology has been proposed for feeding single-phase utility grid employing a three-phase induction generator fed from wind energy. A self-excited induction generator configuration has been chosen for wide speed operation of wind turbine system, which gives the scope for extracting maximum power available in the wind. In addition to maximum power point tracking (MPPT, the generator can be loaded to its rated capacity for feeding single-phase utility grid using a three-phase induction machine, whereas it is not possible with existing configurations because of the absence of power converters. For the proposed system, MPPT algorithm has been devised by continuously monitoring the grid current and a proportional resonant controller has been employed for grid synchronisation of voltage source inverter with single-phase grid. A MATLAB/Simulink model of the proposed system has been developed to ascertain its successful working by predetermining the overall performance characteristics. The present proposal has also been tested with sag, swell and distortion in the grid voltage. The control strategy has been implemented using field programmable gate array (FPGA controller with modularised programming approach. The efficacy of the system has been demonstrated with the results obtained from an experimental set-up in the laboratory.

High-Speed, Low-Power ADC for Digital Beam Forming (DBF) Systems, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — In Phase 1, Ridgetop Group designed a high-speed, yet low-power silicon germanium (SiGe)-based, analog-to-digital converter (ADC) to be a key element for digital...

State control of translational movement in high-speed Maglev transportation systems

Energy Technology Data Exchange (ETDEWEB)

Schnieder, E

1981-01-01

The combination of state control with cascade control satisfies all demands made on train movements in a high-speed Maglev transportation system. The inner control loop compensates nonlinearities and disturbances and limits the acceleration. The dynamics of the control loop are determined by the riding characteristics. The superposed speed state control provides for running without overshoot within permissible limits. In order to reach a target point in the shortest possible time, the control signal for initiating the retardation is issued as late as possible and the speed is output as a function of position. The subsequent structure changeover to a position state control causes the train to come to a smooth halt at its destination in an almost optimal time.

LOFT pump speed controller stability and accuracy analysis

International Nuclear Information System (INIS)

Good, R.R.

1978-01-01

Two system modifications to the primary coolant pumps motor generators control systems have recently been completed. The range of pump speed operation has been extended and the scoop tube positioner motor replaced. This has necessitated a re-analysis of PSMG stability throughout its range of operation. System accuracy requirements of less than 4 Hz differential pump speed when operating at less than 35 Hz and 8.5 Hz differential pump speed when operating at greater than 35 Hz can be guaranteed by specifying the gain of the system. The installation of the new scoop tube positioner motor will increase the PSMG system's bandwidth and stability. Low speed pump trips should be carefully evaluated if the pump's operational range is to extend to 10 Hz

Control of variable speed wind turbine with doubly-fed induction generator

Energy Technology Data Exchange (ETDEWEB)

Hansen, A.D.; Soerensen, P. [Risoe National Lab., Wind Energy Dept., Roskilde (Denmark); Iov, F.; Blaabjerg, F. [Aalborg Univ., Inst. of Energy Technology, Aalborg (Denmark)

2004-07-01

draIn this paper, a Control method suitable for a variable speed grid connected pitch-controlled wind turbine with doubly-fed induction generator (DFIG) is developed. The targets of the Control system are: 1) to Control the power drawn from the wind turbine in order to track the wind turbine optimum operation point 2) to limit the power in case of high wind speeds and 3) to Control the reactive power interchanged between the wind turbine generator and the grid. The considered configuration of DFIG is an induction generator with a wound rotor connected to the grid through a back-to-back power converter and a stator directly connected to the grid. The paper presents the overall Control system of the variable speed DFIG wind turbine, with focus on the Control strategies and algorithms applied at each hierarchical Control level of the wind turbine. There are two Control levels: a DFIG Control level and wind turbine Control level. The DFIG Control level contains a fast Control of the power converter and of the doubly-fed induction generator and it has as goal to Control the active and reactive power of the wind turbine independently. The wind turbine Control level supervises with Control signals both the DFIG Control level and the hydraulic pitch Control system of the wind turbine. The present Control method is designed for normal continuous operations. The variable speed/variable pitch wind turbine with doubly-fed induction generator is implemented in the dynamic power system simulation tool DIgSILENT, which makes possible to investigate the dynamic performance of gid-connected wind turbines as a part of realistic electrical grid models. Several significant simulation results are performed With the overall Control-implemented algorithm applied on a variable speed, variable pitch wind turbine model. (au)

Control of variable speed wind turbines with doubly-fed induction generators

Energy Technology Data Exchange (ETDEWEB)

Hansen, A.D.; Soerensen, P.; Iov, F.; Blaabjerg, F.

2005-07-01

The paper presents an overall control method for variable speed pitch controlled wind turbines with doubly-fed induction generators (DFIG). Emphasis is on control strategies and algorithms applied at each hierarchical control level of the wind turbine. The objectives of the control system are: 1) to control the power drawn from the wind turbine in order to track the wind turbine maximum power operation point, 2) to limit the power in case of large wind speeds, and 3) to control the reactive power interchanged between the wind turbine generator and the grid. The present control method is designed for normal continuous operations. The strongest feature of the implemented control method is that it allows the turbine to operate with the optimum power efficiency over a wide range of wind speeds. The model of the variable speed, variable pitch wind turbine with doubly-fed induction generator is implemented in the dynamic power system simulation tool DlgSILENT PowerFactory which allows investigation of the dynamic performance of grid-connected wind turbines within realistic electrical grid models. Simulation results are presented and analysed in different normal operating conditions. (author)

Control design for a pitch-regulated, variable speed wind turbine

Energy Technology Data Exchange (ETDEWEB)

Hansen, M.H.; Hansen, A.; Larsen, T.J.; Oeye, S.; Soerensen, P.; Fuglsang, P.

2005-01-01

The three different controller designs presented herein are similar and all based on PI-regulation of rotor speed and power through the collective blade pitch angle and generator moment. The aeroelastic and electrical modelling used for the time-domain analysis of these controllers are however different, which makes a directly quantitative comparison difficult. But there are some observations of similar behaviours should be mentioned: 1) Very similar step responses in rotor speed, pitch angle, and power are seen for simulations with steps in wind speed. 2) All controllers show a peak in power for wind speed step-up over rated wind speed, which can be almost removed by changing the parameters of the frequency converter. 3) Responses of rotor speed, pitch angle, and power for different simulations with turbulent inflow are similar for all three controllers. Again, there seems to be an advantage of tuning the parameters of the frequency converter to obtain a more constant power output. The dynamic modelling of the power controller is an important result for the inclusion of generator dynamics in the aeroelastic modelling of wind turbines. A reduced dynamic model of the relation between generator torque and generator speed variations is presented; where the integral term of the inner PI-regulator of rotor current is removed be-cause the time constant is very small compared to the important aeroelastic frequencies. It is shown how the parameters of the transfer function for the remaining control system with the outer PI-regulator of power can be derived from the generator data sheet. The main results of the numerical optimisation of the control parameters in the pitch PI-regulator performed in Chapter 6 are the following: 1) Numerical optimization can be used to tune controller parameters, especially when the optimization is used as refinement of a qualified initial guess. 2) The design model used to calculate the initial value parameters, as described in Chapter 3

Overall control strategy of variable speed doubly-fed induction generator wind turbine

Energy Technology Data Exchange (ETDEWEB)

Hansen, Anca D.; Soerensen, Poul [Risoe National Laboratory, Roskilde (Denmark). Wind Energy Dept.; Iov, Florin; Blaabjerg, Frede [Aalborg Univ. (Denmark). Inst. of Energy Technology

2004-07-01

The variable speed doubly-fed induction generator wind turbine is today the most widely used concept. The paper presents an overall control system of the variable speed DFIG wind turbine, with focus on the control strategies and algorithms applied at each hierarchical control level of the wind turbine. The present control method is designed for normal continuous operations. The strongest feature of the implemented control method is that it allows the turbine to operate with the optimum power efficiency over a wider range of wind speeds. The variable speed/variable pitch wind turbine with doubly-fed induction generator is implemented in the dynamic power system simulation tool DIgSILENT. Simulation results are performed and analyzed in different normal operating conditions.

A new method for speed control of a DC motor using magnetorheological clutch

Science.gov (United States)

Nguyen, Quoc Hung; Choi, Seung-Bok

2014-03-01

In this research, a new method to control speed of DC motor using magnetorheological (MR) clutch is proposed and realized. Firstly, the strategy of a DC motor speed control using MR clutch is proposed. The MR clutch configuration is then proposed and analyzed based on Bingham-plastic rheological model of MR fluid. An optimal designed of the MR clutch is then studied to find out the optimal geometric dimensions of the clutch that can transform a required torque with minimum mass. A prototype of the optimized MR clutch is then manufactured and its performance characteristics are experimentally investigated. A DC motor speed control system featuring the optimized MR clutch is designed and manufactured. A PID controller is then designed to control the output speed of the system. In order to evaluate the effectiveness of the proposed DC motor speed control system, experimental results of the system such as speed tracking performance are obtained and presented with discussions.

Speed control issues for tunnel-in-the-sky displays with predictor

Science.gov (United States)

Sachs, Gottfried; Sperl, Roman

2001-08-01

Speed control issues are considered for tunnel-in-the-sky displays with a predictor presenting guidance information in a 3-dimensional format for flight path control. Factors driving the predictor design are described. With reference to the resulting predictor control law, it is shown that the pilot-predictor-aircraft system is stable for operation on the frontside of the power-required curve and unstable for operation on the reverse. This instability can be removed by thrust control. It is shown that this control loop is supported by the predictor control law because of favorable coupling effects between the two loops involved. Furthermore, an appropriate speed indication in the tunnel-in-the-sky display is considered an aid in manual speed control. The theoretical findings are supported by experimental results from pilot-in-the-loop simulations.

Indirect sensorless speed control of a PMSG for wind application

DEFF Research Database (Denmark)

Diaz, S.A.; Silva, C.; Juliet, J.

2009-01-01

the method usually referred in the literature as indirect speed control (ISC). The principle of this method is the regulation of the generator torque as function of rotor speed such that the steady state operation is at the MPPT. This strategy normally requires the knowledge of the shaft speed to determinate...... in the whole wind generator system a sensorless scheme is proposed, thereby avoiding problems of electromagnetic interferences and failures in the position sensor. Usually, in wind drive system, the generator is not operated a very low speeds, therefore problems related to low back-emf for flux estimation...... the reference torque and rotor position for the orientation of the vector torque control of the PMSG. To achieve both, speed and position estimation, the sensorless technique based in back-emf estimation is proposed. Also in this paper, a laboratory set-up is described. The experimental bench is composed...

Multivariable Techniques for High-Speed Research Flight Control Systems

Science.gov (United States)

Newman, Brett A.

1999-01-01

This report describes the activities and findings conducted under contract with NASA Langley Research Center. Subject matter is the investigation of suitable multivariable flight control design methodologies and solutions for large, flexible high-speed vehicles. Specifically, methodologies are to address the inner control loops used for stabilization and augmentation of a highly coupled airframe system possibly involving rigid-body motion, structural vibrations, unsteady aerodynamics, and actuator dynamics. Design and analysis techniques considered in this body of work are both conventional-based and contemporary-based, and the vehicle of interest is the High-Speed Civil Transport (HSCT). Major findings include: (1) control architectures based on aft tail only are not well suited for highly flexible, high-speed vehicles, (2) theoretical underpinnings of the Wykes structural mode control logic is based on several assumptions concerning vehicle dynamic characteristics, and if not satisfied, the control logic can break down leading to mode destabilization, (3) two-loop control architectures that utilize small forward vanes with the aft tail provide highly attractive and feasible solutions to the longitudinal axis control challenges, and (4) closed-loop simulation sizing analyses indicate the baseline vane model utilized in this report is most likely oversized for normal loading conditions.

Decoupled Speed and Torque Control of IPMSM Drives Using a Novel Load Torque Estimator

Directory of Open Access Journals (Sweden)

ZAKY, M.

2017-08-01

Full Text Available This paper proposes decoupled speed and torque control of interior permanent magnet synchronous motor (IPMSM drives using a novel load torque estimator (LTE. The proposed LTE is applied for computing a load torque and yielding a feed-forward value in the speed controller to separate the torque control from the speed control. Indirect flux weakening using direct current component is obtained for high speed operation of the IPMSM drive, and its value for maximum torque per ampere (MTPA control in constant torque region is also used. LTE uses values of direct and quadrature currents to improve the behavior of the speed controller under the reference tracking and torque disturbances. The complete IPMSM drive by Matlab/Simulink is built. The effectiveness of the proposed control scheme using an experimental setup of the complete drive system implemented on a DSP-DS1102 control board is confirmed. Extensive results over a wide speed range are verified. The efficacy of the proposed method is confirmed in comparison to a conventional PI controller under both the reference speed tracking and load torque disturbance.

Performance Evaluation and Slip Regulation Control of an Asymmetrical Parameter Type Two-Phase Induction Motor Drive Using a Three-Leg Voltage Source Inverter

Science.gov (United States)

Piyarat, Wekin; Kinnares, Vijit

This paper presents a performance evaluation and a simple speed control method of an asymmetrical parameter type two-phase induction motor drive using a three-leg VSI (Voltage Source Inverter). The two-phase induction motor is adapted from an existing single-phase induction motor resulting in impedance unbalance between main and auxiliary windings. The unbalanced two-phase inverter outputs with orthogonal displacement based on a SPWM (Sinusoidal Pulse Width Modulation) method are controlled with appropriate amplitudes for improving the motor performance. Dynamic simulation of the proposed drive system is given. A simple speed controller based on a slip regulation method is designed. The overall system is implemented on a DSP (Digital Signal Processor) board. The validity of the proposed system is verified by simulation and experimental results.

Variable Speed Rotor System, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Variable speed rotors will give helicopters several advantages: higher top speed, greater fuel efficiency, momentary emergency over-power, resonance detuning...

The Effect of Concurrent Visual Feedback on Controlling Swimming Speed

Directory of Open Access Journals (Sweden)

Szczepan Stefan

2016-03-01

Full Text Available Introduction. Developing the ability to control the speed of swimming is an important part of swimming training. Maintaining a defined constant speed makes it possible for the athlete to swim economically at a low physiological cost. The aim of this study was to determine the effect of concurrent visual feedback transmitted by the Leader device on the control of swimming speed in a single exercise test. Material and methods. The study involved a group of expert swimmers (n = 20. Prior to the experiment, the race time for the 100 m distance was determined for each of the participants. In the experiment, the participants swam the distance of 100 m without feedback and with visual feedback. In both variants, the task of the participants was to swim the test distance in a time as close as possible to the time designated prior to the experiment. In the first version of the experiment (without feedback, the participants swam the test distance without receiving real-time feedback on their swimming speed. In the second version (with visual feedback, the participants followed a beam of light moving across the bottom of the swimming pool, generated by the Leader device. Results. During swimming with visual feedback, the 100 m race time was significantly closer to the time designated. The difference between the pre-determined time and the time obtained was significantly statistically lower during swimming with visual feedback (p = 0.00002. Conclusions. Concurrently transmitting visual feedback to athletes improves their control of swimming speed. The Leader device has proven useful in controlling swimming speed.

Implementation Of Automatic Wiper Speed Control And Headlight Modes Control Systems Using Fuzzy Logic

Directory of Open Access Journals (Sweden)

ThetKoKo

2015-07-01

Full Text Available Abstract This research paper describes the design and simulation of the automatic wiper speed and headlight modes controllers using fuzzy logic. This proposed system consists of a fuzzy logic controller to control a cars wiper speed and headlight modes. The automatic wiper system detects the rain and its intensity. And according to the rain intensity the wiper speed is automatically controlled. Headlight modes automatically changes either from low beam mode to high beam mode or form high beam mode to low beam mode depending on the light intensity from the other vehicle coming from the opposite direction. The system comprises of PIC impedance sensor piezoelectric vibration sensor LDR headlamps and a DC motor to accurate the windshield wiper. Piezoelectric sensor is used to detect the rain intensity which is based on the piezoelectric effect. MATLAB software is used to achieve the designed goal.

Phase Control in Nonlinear Systems

Science.gov (United States)

Zambrano, Samuel; Seoane, Jesús M.; Mariño, Inés P.; Sanjuán, Miguel A. F.; Meucci, Riccardo

The following sections are included: * Introduction * Phase Control of Chaos * Description of the model * Numerical exploration of phase control of chaos * Experimental evidence of phase control of chaos * Phase Control of Intermittency in Dynamical Systems * Crisis-induced intermittency and its control * Experimental setup and implementation of the phase control scheme * Phase control of the laser in the pre-crisis regime * Phase control of the intermittency after the crisis * Phase control of the intermittency in the quadratic map * Phase Control of Escapes in Open Dynamical Systems * Control of open dynamical systems * Model description * Numerical simulations and heuristic arguments * Experimental implementation in an electronic circuit * Conclusions and Discussions * Acknowledgments * References

Low speed hybrid generalized predictive control of a gasoline-propelled car.

Science.gov (United States)

Romero, M; de Madrid, A P; Mañoso, C; Milanés, V

2015-07-01

Low-speed driving in traffic jams causes significant pollution and wasted time for commuters. Additionally, from the passengers׳ standpoint, this is an uncomfortable, stressful and tedious scene that is suitable to be automated. The highly nonlinear dynamics of car engines at low-speed turn its automation in a complex problem that still remains as unsolved. Considering the hybrid nature of the vehicle longitudinal control at low-speed, constantly switching between throttle and brake pedal actions, hybrid control is a good candidate to solve this problem. This work presents the analytical formulation of a hybrid predictive controller for automated low-speed driving. It takes advantage of valuable characteristics supplied by predictive control strategies both for compensating un-modeled dynamics and for keeping passengers security and comfort analytically by means of the treatment of constraints. The proposed controller was implemented in a gas-propelled vehicle to experimentally validate the adopted solution. To this end, different scenarios were analyzed varying road layouts and vehicle speeds within a private test track. The production vehicle is a commercial Citroën C3 Pluriel which has been modified to automatically act over its throttle and brake pedals. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Energy-Based Adaptive Sliding Mode Speed Control for Switched Reluctance Motor Drive

Directory of Open Access Journals (Sweden)

M. M. Namazi Isfahani

2012-03-01

Full Text Available Torque ripple minimization of switched reluctance motor drives is a major subject based on these drives’ extensive use in the industry. In this paper, by using a well-known cascaded torque control structure and taking the machine physical structure characteristics into account, the proposed energy-based (passivity-based adaptive sliding algorithm derived from the view point of energy dissipation, control stability and algorithm robustness. First, a nonlinear dynamic model is developed and decomposed into separate slow and fast passive subsystems which are interconnected by negative feedbacks. Then, an outer loop speed control is employed by adaptive sliding controller to determine the appropriate torque command. Finally, to reduce torque ripple in switched reluctance motor a high-performance passivity-based current controller is proposed. It can overcome the inherent nonlinear characteristics of the system and make the whole system robust to uncertainties and bounded disturbances. The performance of the proposed controller algorithm has been demonstrated in simulation, and experimental using a 4KW, four-phase, 8/6 pole SRM DSP-based drive system.

Adaptive sensorless field oriented control of PM motors including zero speed

DEFF Research Database (Denmark)

Rasmussen, Henrik; Vadstrup, P.; Børsting, H.

2004-01-01

This paper presents a simple control method for controlling permanent magnet synchronous motors (PMSM) in a wide speed range without a shaft sensor. An adaptive observer is used for estimation of the rotor position and speed of a permanent magnet synchronous motors (PMSM). The observer compensates...... for voltage offsets and permanent magnet strength variations. The adaption structure for estimating the strength of the permanent magnet is determined from a Lyapunov stability proof. 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 applicability of the method the controller has been implemented and tested on a 800 W motor....

Artificial intelligence-based speed control of DTC induction motor drives - A comparative study

Energy Technology Data Exchange (ETDEWEB)

Gadoue, S.M.; Giaouris, D.; Finch, J.W. [School of Electrical, Electronic and Computer Engineering, Newcastle University, Newcastle upon Tyne NE1 7RU (United Kingdom)

2009-01-15

The design of the speed controller greatly affects the performance of an electric drive. A common strategy to control an induction machine is to use direct torque control combined with a PI speed controller. These schemes require proper and continuous tuning and therefore adaptive controllers are proposed to replace conventional PI controllers to improve the drive's performance. This paper presents a comparison between four different speed controller design strategies based on artificial intelligence techniques; two are based on tuning of conventional PI controllers, the third makes use of a fuzzy logic controller and the last is based on hybrid fuzzy sliding mode control theory. To provide a numerical comparison between different controllers, a performance index based on speed error is assigned. All methods are applied to the direct torque control scheme and each control strategy has been tested for its robustness and disturbance rejection ability. (author)

Control Method for Variable Speed Wind Turbines to Support Temporary Primary Frequency Control

DEFF Research Database (Denmark)

Wang, Haijiao; Chen, Zhe; Jiang, Quanyuan

2014-01-01

This paper develops a control method for variable speed wind turbines (VSWTs) to support temporary primary frequency control of power system. The control method contains two parts: (1) up-regulate support control when a frequency drop event occurs; (2) down-regulate support control when a frequen...

Embedded system based on a real time fuzzy motor speed controller

Directory of Open Access Journals (Sweden)

Ebrahim Abd El-Hamid Mohamed Ramadan

2014-06-01

Full Text Available This paper describes an implementation of a fuzzy logic control (FLC system and a/the conventional proportional-integral (PI controller for speed control of DC motor, based on field programmable gate array (FPGA circuit. The proposed scheme is aimed to improve the tracking performance and to eliminate the load disturbance in the speed control of DC motors. The proposed fuzzy system has been applied to a permanent magnet DC motor, via a configuration of H-bridge. The fuzzy control algorithm is designed and verified with a nonlinear model, using the MATLAB® tools. Both FLC and conventional PI controller hardware are synthesized, functionally verified and implemented using Xilinx Integrated Software Environment (ISE Version 11.1i. The real time implementation of these controllers is made on Spartan-3E FPGA starter kit (XC3S500E. The practical results showed that the proposed FLC scheme has better tracking performance than the conventional PI controller for the speed control of DC motors.

Speed control for a two-mass drive system using integrated fuzzy estimator and hybrid fuzzy PD/PI controller

International Nuclear Information System (INIS)

Pai, N-S; Kuo, Y-P

2008-01-01

This paper presents a novel speed control scheme for a 2- mass motor drive system. The speed controller is based on the estimated state feedback compensation. The integrated fuzzy observer can give a fast and accuracy estimation of the unmeasured states. Two kinds of hybrid fuzzy proportional-derivative and proportional-integral (HF PD/PI) are proposed to cope with this speed control problem. The first is the static HF PD/PI controller and the second is the dynamic one. Simulation results show that the developed integrated fuzzy observer provide the better estimation performance than that of the Kalman filter and the proposed control schemes can effectively track the desired speed in the presence of load disturbance

Functional integration of vertical flight path and speed control using energy principles

Science.gov (United States)

Lambregts, A. A.

1984-01-01

A generalized automatic flight control system was developed which integrates all longitudinal flight path and speed control functions previously provided by a pitch autopilot and autothrottle. In this design, a net thrust command is computed based on total energy demand arising from both flight path and speed targets. The elevator command is computed based on the energy distribution error between flight path and speed. The engine control is configured to produce the commanded net thrust. The design incorporates control strategies and hierarchy to deal systematically and effectively with all aircraft operational requirements, control nonlinearities, and performance limits. Consistent decoupled maneuver control is achieved for all modes and flight conditions without outer loop gain schedules, control law submodes, or control function duplication.

Speed Sensorless Field Oriented Control of an Induction Motor at zero speed with identification of inverter parameters

DEFF Research Database (Denmark)

Rasmussen, Henrik; Vadstrup, P.; Børsting, H.

2002-01-01

Using adaptive Lyapunov design a new approach for the design of an observer for speed sensorless control is developed. The resulting scheme leads to a nonlinear full order observer for the motor states and for the motor and inverter parameters including the rotor speed. Assuming motor parameters ...... known the design achieves stability with guaranteed region of attraction. Experiments demonstrate high dynamic performance even at zero rotor speed based only on the slip frequency caused by the load torque....

MODELLING OF DYNAMIC SPEED LIMITS USING THE MODEL PREDICTIVE CONTROL

Directory of Open Access Journals (Sweden)

Andrey Borisovich Nikolaev

2017-09-01

Full Text Available The article considers the issues of traffic management using intelligent system “Car-Road” (IVHS, which consist of interacting intelligent vehicles (IV and intelligent roadside controllers. Vehicles are organized in convoy with small distances between them. All vehicles are assumed to be fully automated (throttle control, braking, steering. Proposed approaches for determining speed limits for traffic cars on the motorway using a model predictive control (MPC. The article proposes an approach to dynamic speed limit to minimize the downtime of vehicles in traffic.

Generalised pole-placement control of steam turbine speed

Energy Technology Data Exchange (ETDEWEB)

Fernandez-del-Busto, R. [ITESM, Cuernavaca (Mexico). Div. de Ingenieria y Ciencias; Munoz, J. [ITESM, Xochimilco (Mexico). Div. de Ingenieria y Ciencias

1996-12-31

An application of a pole-placement self-tuning predictive control algorithm is developed to regulate speed of a power plant steam turbine model. Two types of system representation (CARMA and CARIMA) are used to test the control algorithm. Simulation results show that when using a CARMA model better results are produced. Two further comparisons are made when using a PI controller and a generalised predictive controller. (author)

Speed adaptation in a powered transtibial prosthesis controlled with a neuromuscular model.

Science.gov (United States)

Markowitz, Jared; Krishnaswamy, Pavitra; Eilenberg, Michael F; Endo, Ken; Barnhart, Chris; Herr, Hugh

2011-05-27

Control schemes for powered ankle-foot prostheses would benefit greatly from a means to make them inherently adaptive to different walking speeds. Towards this goal, one may attempt to emulate the intact human ankle, as it is capable of seamless adaptation. Human locomotion is governed by the interplay among legged dynamics, morphology and neural control including spinal reflexes. It has been suggested that reflexes contribute to the changes in ankle joint dynamics that correspond to walking at different speeds. Here, we use a data-driven muscle-tendon model that produces estimates of the activation, force, length and velocity of the major muscles spanning the ankle to derive local feedback loops that may be critical in the control of those muscles during walking. This purely reflexive approach ignores sources of non-reflexive neural drive and does not necessarily reflect the biological control scheme, yet can still closely reproduce the muscle dynamics estimated from biological data. The resulting neuromuscular model was applied to control a powered ankle-foot prosthesis and tested by an amputee walking at three speeds. The controller produced speed-adaptive behaviour; net ankle work increased with walking speed, highlighting the benefits of applying neuromuscular principles in the control of adaptive prosthetic limbs.

Antisideslip and Antirollover Safety Speed Controller Design for Vehicle on Curved Road

Directory of Open Access Journals (Sweden)

Guo Lie

2014-01-01

Full Text Available When the drivers cannot be aware of the existing of forthcoming curved roads and fail to regulate their safety speeds accordingly, sideslip or rollover may occur with high probability. The antisideslip and antirollover control of vehicle on curved road in automatic highway systems is studied. The safety speed warning system is set before entering the curved road firstly. The speed adhesion control is adopted to shorten the braking distance while decelerating and to guarantee the safety speed. The velocity controller when decelerating on the straight path and the posture controller when driving on curved road are designed, respectively, utilizing integral backstepping technology. Simulation results demonstrate that this control system is characterized by quick and precise tracking and global stability. Consequently, it is able to avoid the dangerous operating conditions, such as sideslip and rollover, and guarantee the safety and directional stability when driving on curved road.

An Adaptive Speed Control Approach for DC Shunt Motors

Directory of Open Access Journals (Sweden)

Ruben Tapia-Olvera

2016-11-01

Full Text Available A B-spline neural networks-based adaptive control technique for angular speed reference trajectory tracking tasks with highly efficient performance for direct current shunt motors is proposed. A methodology for adaptive control and its proper training procedure are introduced. This algorithm sets the control signal without using a detailed mathematical model nor exact values of the parameters of the nonlinear dynamic system. The proposed robust adaptive tracking control scheme only requires measurements of the velocity output signal. Thus, real-time measurements or estimations of acceleration, current and disturbance signals are avoided. Experimental results confirm the efficient and robust performance of the proposed control approach for highly demanding motor operation conditions exposed to variable-speed reference trajectories and completely unknown load torque. Hence, laboratory experimental tests on a direct current shunt motor prove the viability of the proposed adaptive output feedback trajectory tracking control approach.

Speed Loop Control of PMSM Driving Electric Vehicle

DEFF Research Database (Denmark)

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...

Model reference adaptive vector control for induction motor without speed sensor

Directory of Open Access Journals (Sweden)

Bo Fan

2017-01-01

Full Text Available The wide applications of vector control improve the high-accuracy performance of alternating current (AC adjustable speed system. In order to obverse the full-order flux and calculate the real-time speed, this article introduces the motor T equivalent circuit to build a full-order flux observer model, where the current and flux variables of stator and rotor are adopted. Model reference adaptive control is introduced to build the AC motor flux observer. The current output is used as feedback to build the feedback matrix. The calculation method of motor speed, which is part of the inputs of flux observation, is applied to realize the adaptive control. The concept of characteristic function is introduced to calculate the flux, of which the foundation is the variables of composite form of voltage and current models. The characteristic function is deduced as a relative-state variable function. The feedback matrix is improved and designed to ensure the motor flux observer is a smooth switch between current and voltage model in low and high speeds, respectively. Experimental results show that the feedback and characteristic model are feasible, and the vector control with speed sensorless based on the full-order flux observer has better performance and anti-disturbance.

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

Directory of Open Access Journals (Sweden)

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.

76 FR 78 - Federal Motor Vehicle Safety Standard; Engine Control Module Speed Limiter Device

Science.gov (United States)

2011-01-03

... [Docket No. NHTSA-2007-26851] Federal Motor Vehicle Safety Standard; Engine Control Module Speed Limiter... occupants. IIHS stated that on-board electronic engine control modules (ECM) will maintain the desired speed... be equipped with an electronic control module (ECM) that is capable of limiting the maximum speed of...

Energy-optimal speed control of fans and compressor in a refrigeration system

DEFF Research Database (Denmark)

Jakobsen, Arne; Rasmussen, Bjarne D.

1998-01-01

Use of variable speed compressors and variable speed fans for both the evaporator and the condenser makes the refrigeration system more flexible, adds to the degree of freedom of the control system and therefore makes it possible to (on-line) optimise the various speeds involved. Say, for example...... and therefore the achievement of the potential for energy saving. This control/optimisation problem is investigated using a steady-state simulation model....

Sensorless Speed Control of Permanent Magnet Synchronous Motors by Neural Network Algorithm

Directory of Open Access Journals (Sweden)

Ming-Shyan Wang

2014-01-01

Full Text Available The sliding mode control has the merits with respect to the variation of the disturbance and robustness. In this paper, the sensorless sliding-mode observer with least mean squared error approach for permanent magnet synchronous motor (PMSM to detect the rotor position by counter electromotive force and then compute motor speed is designed and implemented. In addition, the neural network control is also used to compensate the PI gain tuning to increase the speed accuracy without regarding the errors of the current measurement and motor noise. In this paper, a digital signal processor TMS320F2812 utilizes its high-speed ADC module to get current feedback information and thus to estimate the rotor position and takes advantage of the built-in modules to achieve SVPWM current control so that the senseless speed control will be accomplished. The correctness and effectiveness of the proposed control system will be verified from the experimental results.

Pitch Angle Control for Variable Speed Wind Turbines

Directory of Open Access Journals (Sweden)

Mouna Ben Smida

2015-08-01

Full Text Available Abstract.Pitch control is a practical technique for power regulation above the rated wind speed it is considered as the most efficient and popular power control method. As conventional pitch control usually use PI controller, the mathematical model of the system should be known well.This paper deals with the operation and the control of the direct driven permanent magnet synchronous generator (PMSG.Different conventional strategies of pitch angle control are described and validated through simulation results under Matlab\\Simulink.

Modelling and control of variable speed wind turbines for power system studies

DEFF Research Database (Denmark)

Michalke, Gabriele; Hansen, Anca Daniela

2010-01-01

and implemented in the power system simulation tool DIgSILENT. Important issues like the fault ride-through and grid support capabilities of these wind turbine concepts are addressed. The paper reveals that advanced control of variable speed wind turbines can improve power system stability. Finally......, it will be shown in the paper that wind parks consisting of variable speed wind turbines can help nearby connected fixed speed wind turbines to ride-through grid faults. Copyright © 2009 John Wiley & Sons, Ltd.......Modern wind turbines are predominantly variable speed wind turbines with power electronic interface. Emphasis in this paper is therefore on the modelling and control issues of these wind turbine concepts and especially on their impact on the power system. The models and control are developed...

A model predictive speed tracking control approach for autonomous ground vehicles

Science.gov (United States)

Zhu, Min; Chen, Huiyan; Xiong, Guangming

2017-03-01

This paper presents a novel speed tracking control approach based on a model predictive control (MPC) framework for autonomous ground vehicles. A switching algorithm without calibration is proposed to determine the drive or brake control. Combined with a simple inverse longitudinal vehicle model and adaptive regulation of MPC, this algorithm can make use of the engine brake torque for various driving conditions and avoid high frequency oscillations automatically. A simplified quadratic program (QP) solving algorithm is used to reduce the computational time, and the approach has been applied in a 16-bit microcontroller. The performance of the proposed approach is evaluated via simulations and vehicle tests, which were carried out in a range of speed-profile tracking tasks. With a well-designed system structure, high-precision speed control is achieved. The system can robustly model uncertainty and external disturbances, and yields a faster response with less overshoot than a PI controller.

High-speed single-shot optical focusing through dynamic scattering media with full-phase wavefront shaping

Science.gov (United States)

Hemphill, Ashton S.; Shen, Yuecheng; Liu, Yan; Wang, Lihong V.

2017-11-01

In biological applications, optical focusing is limited by the diffusion of light, which prevents focusing at depths greater than ˜1 mm in soft tissue. Wavefront shaping extends the depth by compensating for phase distortions induced by scattering and thus allows for focusing light through biological tissue beyond the optical diffusion limit by using constructive interference. However, due to physiological motion, light scattering in tissue is deterministic only within a brief speckle correlation time. In in vivo tissue, this speckle correlation time is on the order of milliseconds, and so the wavefront must be optimized within this brief period. The speed of digital wavefront shaping has typically been limited by the relatively long time required to measure and display the optimal phase pattern. This limitation stems from the low speeds of cameras, data transfer and processing, and spatial light modulators. While binary-phase modulation requiring only two images for the phase measurement has recently been reported, most techniques require at least three frames for the full-phase measurement. Here, we present a full-phase digital optical phase conjugation method based on off-axis holography for single-shot optical focusing through scattering media. By using off-axis holography in conjunction with graphics processing unit based processing, we take advantage of the single-shot full-phase measurement while using parallel computation to quickly reconstruct the phase map. With this system, we can focus light through scattering media with a system latency of approximately 9 ms, on the order of the in vivo speckle correlation time.

Sensorless Speed/Torque Control of DC Machine Using Artificial Neural Network Technique

Directory of Open Access Journals (Sweden)

Rakan Kh. Antar

2017-12-01

Full Text Available In this paper, Artificial Neural Network (ANN technique is implemented to improve speed and torque control of a separately excited DC machine drive. The speed and torque sensorless scheme based on ANN is estimated adaptively. The proposed controller is designed to estimate rotor speed and mechanical load torque as a Model Reference Adaptive System (MRAS method for DC machine. The DC drive system consists of four quadrant DC/DC chopper with MOSFET transistors, ANN, logic gates and routing circuits. The DC drive circuit is designed, evaluated and modeled by Matlab/Simulink in the forward and reverse operation modes as a motor and generator, respectively. The DC drive system is simulated at different speed values (±1200 rpm and mechanical torque (±7 N.m in steady state and dynamic conditions. The simulation results illustratethe effectiveness of the proposed controller without speed or torque sensors.

Event-driven control of a speed varying digital displacement machine

DEFF Research Database (Denmark)

Pedersen, Niels Henrik; Johansen, Per; Andersen, Torben O.

2017-01-01

. The controller synthesis is carried out as a discrete optimal deterministic problem with full state feedback. Based on a linear analysis of the feedback control system, stability is proven in a pre-specified operation region. Simulation of a non-linear evaluation model with the controller implemented shows great...... be treated as a Discrete Linear Time Invariant control problem with synchronous sampling rate. To make synchronous linear control theory applicable for a variable speed digital displacement machine, a method based on event-driven control is presented. Using this method, the time domain differential equations...... are converted into the spatial (position) domain to obtain a constant sampling rate and thus allowing for use of classical control theory. The method is applied to a down scaled digital fluid power motor, where the motor speed is controlled at varying references under varying pressure and load torque conditions...

Low-Speed Stability-and-Control and Ground-Effects Measurements on the Industry Reference High Speed Civil Transport

Science.gov (United States)

Kemmerly, Guy T.; Campbell, Bryan A.; Banks, Daniel W.; Yaros, Steven F.

1999-01-01

As a part of a national effort to develop an economically feasible High Speed Civil Transport (HSCT), a single configuration has been accepted as the testing baseline by the organizations working in the High Speed Research (HSR) program. The configuration is based on a design developed by the Boeing Company and is referred to as the Reference H (Ref H). The data contained in this report are low-speed stability-and-control and ground-effect measurements obtained on a 0.06 scale model of the Ref H in a subsonic tunnel.

Small-Signal Modeling, Analysis and Testing of Parallel Three-Phase-Inverters with A Novel Autonomous Current Sharing Controller

DEFF Research Database (Denmark)

Guan, Yajuan; Quintero, Juan Carlos Vasquez; Guerrero, Josep M.

2015-01-01

A novel simple and effective autonomous currentsharing controller for parallel three-phase inverters is employed in this paper. The novel controller is able to endow to the system high speed response and precision in contrast to the conventional droop control as it does not require calculating any...... active or reactive power, instead it uses a virtual impedance loop and a SFR phase-locked loop. The small-signal model of the system was developed for the autonomous operation of inverter-based microgrid with the proposed controller. The developed model shows large stability margin and fast transient...

Hardware Evolution of Analog Speed Controllers for a DC Motor

Science.gov (United States)

Gwaltney, David A.; Ferguson, Michael I.

2003-01-01

This viewgraph presentation provides information on the design of analog speed controllers for DC motors on aerospace systems. The presentation includes an overview of controller evolution, evolvable controller configuration, an emphasis on proportion integral (PI) controllers, schematic diagrams, and experimental results.

Adaptive Torque Control of Variable Speed Wind Turbines

Energy Technology Data Exchange (ETDEWEB)

Johnson, K. E.

2004-08-01

The primary focus of this work is a new adaptive controller that is designed to resemble the standard non-adaptive controller used by the wind industry for variable speed wind turbines below rated power. This adaptive controller uses a simple, highly intuitive gain adaptation law designed to seek out the optimal gain for maximizing the turbine's energy capture. It is designed to work even in real, time-varying winds.

Scandium doping brings speed improvement in Sb2Te alloy for phase change random access memory application.

Science.gov (United States)

Chen, Xin; Zheng, Yonghui; Zhu, Min; Ren, Kun; Wang, Yong; Li, Tao; Liu, Guangyu; Guo, Tianqi; Wu, Lei; Liu, Xianqiang; Cheng, Yan; Song, Zhitang

2018-05-01

Phase change random access memory (PCRAM) has gained much attention as a candidate for nonvolatile memory application. To develop PCRAM materials with better properties, especially to draw closer to dynamic random access memory (DRAM), the key challenge is to research new high-speed phase change materials. Here, Scandium (Sc) has been found it is helpful to get high-speed and good stability after doping in Sb 2 Te alloy. Sc 0.1 Sb 2 Te based PCRAM cell can achieve reversible switching by applying even 6 ns voltage pulse experimentally. And, Sc doping not only promotes amorphous stability but also improves the endurance ability comparing with pure Sb 2 Te alloy. Moreover, according to DFT calculations, strong Sc-Te bonds lead to the rigidity of Sc centered octahedrons, which may act as crystallization precursors in recrystallization process to boost the set speed.

Considering Variable Road Geometry in Adaptive Vehicle Speed Control

Directory of Open Access Journals (Sweden)

Xinping Yan

2013-01-01

Full Text Available Adaptive vehicle speed control is critical for developing Advanced Driver Assistance Systems (ADAS. Vehicle speed control considering variable road geometry has become a hotspot in ADAS research. In this paper, first, an exploration of intrinsic relationship between vehicle operation and road geometry is made. Secondly, a collaborative vehicle coupling model, a road geometry model, and an AVSC, which can respond to variable road geometry in advance, are developed. Then, based on H∞ control method and the minimum energy principle, a performance index is specified by a cost function for the proposed AVSC, which can explicitly consider variable road geometry in its optimization process. The proposed AVSC is designed by the Hamilton-Jacobi Inequality (HJI. Finally, simulations are carried out by combining the vehicle model with the road geometry model, in an aim of minimizing the performance index of the AVSC. Analyses of the simulation results indicate that the proposed AVSC can automatically and effectively regulate speed according to variable road geometry. It is believed that the proposed AVSC can be used to improve the economy, comfort, and safety effects of current ADAS.

Embedded systems design for high-speed data acquisition and control

CERN Document Server

Di Paolo Emilio, Maurizio

2015-01-01

This book serves as a practical guide for practicing engineers who need to design embedded systems for high-speed data acquisition and control systems. A minimum amount of theory is presented, along with a review of analog and digital electronics, followed by detailed explanations of essential topics in hardware design and software development. The discussion of hardware focuses on microcontroller design (ARM microcontrollers and FPGAs), techniques of embedded design, high speed data acquisition (DAQ) and control systems. Coverage of software development includes main programming techniques, culminating in the study of real-time operating systems. All concepts are introduced in a manner to be highly-accessible to practicing engineers and lead to the practical implementation of an embedded board that can be used in various industrial fields as a control system and high speed data acquisition system.   • Describes fundamentals of embedded systems design in an accessible manner; • Takes a problem-solving ...

Characterization of Ge Doping on Sb_2Te_3 for High-Speed Phase Change Memory Application

International Nuclear Information System (INIS)

Zhu Yue-Qin; Xie Hua-Qing; Zhang Zhong-Hua; Song San-Nian; Song Zhi-Tang; Shen Lan-Lan; Li Le; Wu Liang-Cai; Liu Bo

2015-01-01

The phase change material of Ge-doped Sb_2Te_3 is shown to have higher crystallization temperature and better thermal stability compared with pure Sb_2Te_3. Ge_0_._1_1Sb_2Te_3 alloys are considered to be a potential candidate for phase change random access memories, as proved by a higher crystallization temperature, a better data retention ability, and a faster switching speed in comparison with those of Ge_2Sb_2Te_5. In addition, Ge_0_._1_1Sb_2Te_3 presents extremely rapid reverse switching speed (10 ns), and up to 10"5 programming cycles are obtained with stable set and reset resistances. (paper)

Off-line tuning of a PI speed controller for a permanent magnet brushless DC motor using DSP

Energy Technology Data Exchange (ETDEWEB)

Demirtas, Metin, E-mail: mdtas@balikesir.edu.t [Electrical and Electronics Engineering Department, Balikesir University, Balikesir (Turkey)

2011-01-15

In this paper, a new method of tuning Proportional Integral (PI) coefficients for a permanent magnet brushless DC (PMBLDC) motor drives is proposed. Artificial neural network is used to identify the whole system using maximum overshoot and settling time obtained from the application circuit for different K{sub p}-K{sub i} pairs. Optimal values of PI controller coefficients are obtained using genetic algorithm. Motion Control Kit (MCK243) is used to carry out digital motion control applications. The MCK243 kit includes a power module and a three-phase brushless motor. TMS320F243 programs are used for PMBLDC motor speed control. Experimental results are given to show the validity of this method.

Advancement and Application of Multi-Phase CFD Modeling to High Speed Supercavitating Flows

Science.gov (United States)

2013-08-13

October 2008 - December 2013 4. TITLE AND SUBTITLE Advancement and Application of Multi-Phase CFD Modeling to High Speed Supercavitating Flows...influence cavity hysteresis behavior. These observations are used to guide improved supercavitating -vehicle analyses including numerical predictions...experiments, and modeling 15. SUBJECT TERMS supercavitation , computational fluid dynamics, multiphase flow 16. SECURITY CLASSIFICATION OF: a

Effective and Robust Generalized Predictive Speed Control of Induction Motor

Directory of Open Access Journals (Sweden)

Patxi Alkorta

2013-01-01

Full Text Available This paper presents and validates a new proposal for effective speed vector control of induction motors based on linear Generalized Predictive Control (GPC law. The presented GPC-PI cascade configuration simplifies the design with regard to GPC-GPC cascade configuration, maintaining the advantages of the predictive control algorithm. The robust stability of the closed loop system is demonstrated by the poles placement method for several typical cases of uncertainties in induction motors. The controller has been tested using several simulations and experiments and has been compared with Proportional Integral Derivative (PID and Sliding Mode (SM control schemes, obtaining outstanding results in speed tracking even in the presence of parameter uncertainties, unknown load disturbance, and measurement noise in the loop signals, suggesting its use in industrial applications.

Model-free adaptive speed control on travelling wave ultrasonic motor

Science.gov (United States)

Di, Sisi; Li, Huafeng

2018-01-01

This paper introduced a new data-driven control (DDC) method for the speed control of ultrasonic motor (USM). The model-free adaptive control (MFAC) strategy was presented in terms of its principles, algorithms, and parameter selection. To verify the efficiency of the proposed method, a speed-frequency-time model, which contained all the measurable nonlinearity and uncertainties based on experimental data was established for simulation to mimic the USM operation system. Furthermore, the model was identified using particle swarm optimization (PSO) method. Then, the control of the simulated system using MFAC was evaluated under different expectations in terms of overshoot, rise time and steady-state error. Finally, the MFAC results were compared with that of proportion iteration differentiation (PID) to demonstrate its advantages in controlling general random system.

Phase Error Caused by Speed Mismatch Analysis in the Line-Scan Defect Detection by Using Fourier Transform Technique

Directory of Open Access Journals (Sweden)

Eryi Hu

2015-01-01

Full Text Available The phase error caused by the speed mismatch issue is researched in the line-scan images capturing 3D profile measurement. The experimental system is constructed by a line-scan CCD camera, an object moving device, a digital fringe pattern projector, and a personal computer. In the experiment procedure, the detected object is moving relative to the image capturing system by using a motorized translation stage in a stable velocity. The digital fringe pattern is projected onto the detected object, and then the deformed patterns are captured and recorded in the computer. The object surface profile can be calculated by the Fourier transform profilometry. However, the moving speed mismatch error will still exist in most of the engineering application occasion even after an image system calibration. When the moving speed of the detected object is faster than the expected value, the captured image will be compressed in the moving direction of the detected object. In order to overcome this kind of measurement error, an image recovering algorithm is proposed to reconstruct the original compressed image. Thus, the phase values can be extracted much more accurately by the reconstructed images. And then, the phase error distribution caused by the speed mismatch is analyzed by the simulation and experimental methods.

Wind Turbine Generator Modeling and Simulation Where Rotational Speed is the Controlled Variable

DEFF Research Database (Denmark)

Mihet-Popa, Lucian; Blaabjerg, Frede; Boldea, Ion

2004-01-01

the interaction between a wind turbine and the power system. The model is intended to simulate the behaviour of the wind turbine using induction generators both during normal operation. Sample simulation results for two induction generators (2/0.5 MW) validate the fundamental issues.......To optimise the power produced in a wind turbine, the speed of the turbine should vary with the wind speed. A simple control method is proposed that will allow an induction machine to run a turbine at its maximum power coefficient. Various types of power control strategies have been suggested...... for application in variable speed wind turbines. The usual strategy is to control the power or the torque acting on the wind turbine shafts. This paper presents an alternative control strategy, where the rotational speed is the controlled variable. The paper describes a model, which is being developed to simulate...

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

Directory of Open Access Journals (Sweden)

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.

Variable speed wind turbine generator system with current controlled voltage source inverter

International Nuclear Information System (INIS)

Muyeen, S.M.; Al-Durra, Ahmed; Tamura, J.

2011-01-01

highlights: → Current controlled voltage source inverter scheme for wind power application. → Low voltage ride through of wind farm. → Variable speed wind turbine driven permanent magnet synchronous generator-operation and control. -- Abstract: The present popular trend of wind power generation is to use variable speed wind turbine (VSWT) driving a doubly fed induction generator (DFIG), wound field synchronous generator (WFSG) or permanent magnet synchronous generator (PMSG). Among them, stability analyses of DFIG type of VSWT have already been reported in many literatures. However, transient stability and low voltage ride through (LVRT) characteristics analyses for synchronous generator type of VSWT is not sufficient enough. This paper focuses on detailed LVRT characteristic analysis of variable speed wind turbine driving a PMSG (VSWT-PMSG) with current controlled voltage source inverter (CC-VSI). Modeling and suitable control strategies for overall system are developed to augment the low voltage ride through capability of variable speed wind generator, considering recent wind farm grid code. Both symmetrical and unsymmetrical faults are analyzed as network disturbances in this paper. The permanent fault due to unsuccessful reclosing of circuit breakers is taken into consideration, which is a salient feature of this study. Moreover, the dynamic characteristic is analyzed using real wind speed data measured in Hokkaido Island, Japan. The proposed control scheme is simulated by using the standard power system simulation package PSCAD/EMTDC and results are verified by comparing that of voltage controlled voltage source inverter scheme available in power system literature.

Variable speed wind turbine generator system with current controlled voltage source inverter

Energy Technology Data Exchange (ETDEWEB)

Muyeen, S.M., E-mail: muyeen0809@yahoo.co [Dept. of Electrical Engineering, Petroleum Institute, P.O. Box 2533, Abu Dhabi (United Arab Emirates); Al-Durra, Ahmed [Dept. of Electrical Engineering, The Petroleum Institute, P.O. Box 2533, Abu Dhabi (United Arab Emirates); Tamura, J. [Dept. of EEE, Kitami Institute of Technology, 165 Koen-cho, Kitami 090-8507 (Japan)

2011-07-15

highlights: {yields} Current controlled voltage source inverter scheme for wind power application. {yields} Low voltage ride through of wind farm. {yields} Variable speed wind turbine driven permanent magnet synchronous generator-operation and control. -- Abstract: The present popular trend of wind power generation is to use variable speed wind turbine (VSWT) driving a doubly fed induction generator (DFIG), wound field synchronous generator (WFSG) or permanent magnet synchronous generator (PMSG). Among them, stability analyses of DFIG type of VSWT have already been reported in many literatures. However, transient stability and low voltage ride through (LVRT) characteristics analyses for synchronous generator type of VSWT is not sufficient enough. This paper focuses on detailed LVRT characteristic analysis of variable speed wind turbine driving a PMSG (VSWT-PMSG) with current controlled voltage source inverter (CC-VSI). Modeling and suitable control strategies for overall system are developed to augment the low voltage ride through capability of variable speed wind generator, considering recent wind farm grid code. Both symmetrical and unsymmetrical faults are analyzed as network disturbances in this paper. The permanent fault due to unsuccessful reclosing of circuit breakers is taken into consideration, which is a salient feature of this study. Moreover, the dynamic characteristic is analyzed using real wind speed data measured in Hokkaido Island, Japan. The proposed control scheme is simulated by using the standard power system simulation package PSCAD/EMTDC and results are verified by comparing that of voltage controlled voltage source inverter scheme available in power system literature.

Two-phase strategy of neural control for planar reaching movements: II--relation to spatiotemporal characteristics of movement trajectory.

Science.gov (United States)

Rand, Miya K; Shimansky, Yury P

2013-09-01

In the companion paper utilizing a quantitative model of optimal motor coordination (Part I, Rand and Shimansky, in Exp Brain Res 225:55-73, 2013), we examined coordination between X and Y movement directions (XYC) during reaching movements performed under three prescribed speeds, two movement amplitudes, and two target sizes. The obtained results indicated that the central nervous system (CNS) utilizes a two-phase strategy, where the initial and the final phases correspond to lower and higher precision of information processing, respectively, for controlling goal-directed reach-type movements to optimize the total cost of task performance including the cost of neural computations. The present study investigates how two different well-known concepts used for describing movement performance relate to the concepts of optimal XYC and two-phase control strategy. First, it is examined to what extent XYC is equivalent to movement trajectory straightness. The data analysis results show that the variability, the movement trajectory's deviation from the straight line, increases with an increase in prescribed movement speed. In contrast, the dependence of XYC strength on movement speed is opposite (in total agreement with an assumption of task performance optimality), suggesting that XYC is a feature of much higher level of generality than trajectory straightness. Second, it is tested how well the ballistic and the corrective components described in the traditional concept of two-component model of movement performance match with the initial and the final phase of the two-phase control strategy, respectively. In fast reaching movements, the percentage of trials with secondary corrective submovement was smaller under larger-target shorter-distance conditions. In slower reaching movements, meaningful parsing was impossible due to massive fluctuations in the kinematic profile throughout the movement. Thus, the parsing points determined by the conventional submovement analysis

Brushless DC motor speed control strategy of simulation research

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Xiang Wen

2017-01-01

Full Text Available In view of the brushless DC motor speed regulation problem, an ideal control strategy is designed. Through the model and analysis of Brushless DC motor, the mathematical model of the brushless DC motor is obtained. By comparing three control strategies of PID control strategy, fuzzy control strategy and fuzzy PID control strategy, PID controller, fuzzy controller and fuzzy PID controller are designed respectively for simulation test. The simulation results show that the fuzzy PID controller has good control effect.

Fuzzy Constrained Predictive Optimal Control of High Speed Train with Actuator Dynamics

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Xi Wang

2016-01-01

Full Text Available We investigate the problem of fuzzy constrained predictive optimal control of high speed train considering the effect of actuator dynamics. The dynamics feature of the high speed train is modeled as a cascade of cars connected by flexible couplers, and the formulation is mathematically transformed into a Takagi-Sugeno (T-S fuzzy model. The goal of this study is to design a state feedback control law at each decision step to enhance safety, comfort, and energy efficiency of high speed train subject to safety constraints on the control input. Based on Lyapunov stability theory, the problem of optimizing an upper bound on the cruise control cost function subject to input constraints is reduced to a convex optimization problem involving linear matrix inequalities (LMIs. Furthermore, we analyze the influences of second-order actuator dynamics on the fuzzy constrained predictive controller, which shows risk of potentially deteriorating the overall system. Employing backstepping method, an actuator compensator is proposed to accommodate for the influence of the actuator dynamics. The experimental results show that with the proposed approach high speed train can track the desired speed, the relative coupler displacement between the neighbouring cars is stable at the equilibrium state, and the influence of actuator dynamics is reduced, which demonstrate the validity and effectiveness of the proposed approaches.

The Design of a High Speed Low Power Phase Locked Loop

CERN Document Server

Liu, Tiankuan; Hou, Suen; Liang, Zhihua; Liu, Chonghan; Su, Da-Shung; Teng, Ping-Kun; Xiang, Annie C; Ye, Jingbo

2009-01-01

The upgrade of the ATLAS Liquid Argon Calorimeter readout system calls for the development of radiation tolerant, high speed and low power serializer ASIC. We have designed a phase locked loop using a commercial 0.25-μm Silicon-on- Sapphire (SoS) CMOS technology. Post-layout simulation indicates that tuning range is 3.79 – 5.01 GHz and power consumption is 104 mW. The PLL has been submitted for fabrication. The design and simulation results are presented.

Acoustic grating fringe projector for high-speed and high-precision three-dimensional shape measurements

International Nuclear Information System (INIS)

Yin Xuebing; Zhao Huijie; Zeng Junyu; Qu Yufu

2007-01-01

A new acoustic grating fringe projector (AGFP) was developed for high-speed and high-precision 3D measurement. A new acoustic grating fringe projection theory is also proposed to describe the optical system. The AGFP instrument can adjust the spatial phase and period of fringes with unprecedented speed and accuracy. Using rf power proportional-integral-derivative (PID) control and CCD synchronous control, we obtain fringes with fine sinusoidal characteristics and realize high-speed acquisition of image data. Using the device, we obtained a precise phase map for a 3D profile. In addition, the AGFP can work in running fringe mode, which could be applied in other measurement fields

Regardless-of-Speed Superconducting LSM Controlled-Repulsive MAGLEV Vehicle

Science.gov (United States)

Yoshida, Kinjiro; Egashira, Tatsuya; Hirai, Ryuichi

1996-01-01

This paper proposes a new repulsive Maglev vehicle which a superconducting linear synchronous motor (LSM) can levitate and propel simultaneously, independently of the vehicle speeds. The combined levitation and propulsion control is carried out by controlling mechanical-load angle and armature-current. Dynamic simulations show successful operations with good ride-quality by using a compact control method proposed here.

The effect of speed-accuracy strategy on response interference control in Parkinson's disease.

Science.gov (United States)

Wylie, S A; van den Wildenberg, W P M; Ridderinkhof, K R; Bashore, T R; Powell, V D; Manning, C A; Wooten, G F

2009-07-01

Studies that used conflict paradigms such as the Eriksen Flanker task show that many individuals with Parkinson's disease (PD) have pronounced difficulty resolving the conflict that arises from the simultaneous activation of mutually exclusive responses. This finding fits well with contemporary views that postulate a key role for the basal ganglia in action selection. The present experiment aims to specify the cognitive processes that underlie action selection deficits among PD patients in the context of variations in speed-accuracy strategy. PD patients (n=28) and healthy controls (n=17) performed an arrow version of the flanker task under task instructions that either emphasized speed or accuracy of responses. Reaction time (RT) and accuracy rates decreased with speed compared to accuracy instructions, although to a lesser extent for the PD group. Differences in flanker interference effects among PD and healthy controls depended on speed-accuracy strategy. Compared to the healthy controls, PD patients showed larger flanker interference effects under speed stress. RT distribution analyses suggested that PD patients have greater difficulty suppressing incorrect response activation when pressing for speed. These initial findings point to an important interaction between strategic and computational aspects of interference control in accounting for cognitive impairments of PD. The results are also compatible with recent brain imaging studies that demonstrate basal ganglia activity to co-vary with speed-accuracy adjustments.

High speed, locally controlled data acquisition system for TFTR

International Nuclear Information System (INIS)

Feng, H.K.; Bradish, G.J.

1983-01-01

A high speed, locally controlled, data acquisition and transmission system has been developed by the CICADA (Central Instrumentation Control and Data Acquisition) Group for extracting certain timecritical data during a TFTR pulse and passing it to the control room, 1000 feet distant, to satisfy realtime requirements of frequently sampled variables. The system is designed to utilize any or all of the standard CAMAC (Computer Automated Measurement and Control) modules now employed on the CAMAC links for retrieval of the main body of data, but to operate them in a much faster manner than in a standard CAMAC system. To do this, a pre-programmable ROM sequencer is employed as a controller to transmit commands to the modules at intervals down to one microsecond, replacing the usual CAMAC dedicated computer, and increasing the command rate by an order of magnitude over what could be sent down a Branch Highway. Data coming from any number of channels originating within a single CAMAC ''crate'' is then time-multiplexed and transmitted over a single conductor pair in bi-phase at a 2.5 MHz bit rate using Manchester coding techniques. Benefits gained from this approach include: Reduction in the number of conductors required, elimination of line-to-line skew found in parallel transmission systems, and the capability of being transformer coupled or transmitted over a fiber optic cable to avoid safety hazards and ground loops. The main application for this system so far has been as the feedback path in this closed loop control of currents through the Tokamak's field coils. The paper will treat the system's various applications

PSO-based PID Speed Control of Traveling Wave Ultrasonic Motor under Temperature Disturbance

Science.gov (United States)

Arifin Mat Piah, Kamal; Yusoff, Wan Azhar Wan; Azmi, Nur Iffah Mohamed; Romlay, Fadhlur Rahman Mohd

2018-03-01

Traveling wave ultrasonic motors (TWUSMs) have a time varying dynamics characteristics. Temperature rise in TWUSMs remains a problem particularly in sustaining optimum speed performance. In this study, a PID controller is used to control the speed of TWUSM under temperature disturbance. Prior to developing the controller, a linear approximation model which relates the speed to the temperature is developed based on the experimental data. Two tuning methods are used to determine PID parameters: conventional Ziegler-Nichols(ZN) and particle swarm optimization (PSO). The comparison of speed control performance between PSO-PID and ZN-PID is presented. Modelling, simulation and experimental work is carried out utilizing Fukoku-Shinsei USR60 as the chosen TWUSM. The results of the analyses and experimental work reveal that PID tuning using PSO-based optimization has the advantage over the conventional Ziegler-Nichols method.

Power Control of Permanent Magnet Generator Based Variable Speed Wind Turbines

DEFF Research Database (Denmark)

Deng, Fujin; Chen, Zhe

2009-01-01

When the wind power accounts for a large portion of the grid, it will be required to regulate the active power and reactive power. This paper investigates a MWlevel variable speed wind turbine with a permanent magnet synchronous generator (PMSG). The power control capabilities of two kinds...... of control schemes conducted respectively on this wind turbine under two conditions, including rapid wind speed change and grids faults, are compared. The simulation study of the wind turbine system is conducted using PSCAD/EMTDC, and the results show the different power control capabilities of the two...

Generate stepper motor linear speed profile in real time

Science.gov (United States)

Stoychitch, M. Y.

2018-01-01

In this paper we consider the problem of realization of linear speed profile of stepper motors in real time. We considered the general case when changes of speed in the phases of acceleration and deceleration are different. The new and practical algorithm of the trajectory planning is given. The algorithms of the real time speed control which are suitable for realization to the microcontroller and FPGA circuits are proposed. The practical realization one of these algorithms, using Arduino platform, is given also.

Speed Sensorless mixed sensitivity linear parameter variant H_inf control of the induction motor

NARCIS (Netherlands)

Toth, R.; Fodor, D.

2004-01-01

The paper shows the design of a robust control structure for the speed sensorless vector control of the IM, based on the mixed sensitivity (MS) linear parameter variant (LPV) H8 control theory. The controller makes possible the direct control of the flux and speed of the motor with torque adaptation

On-Chip Enucleation of Bovine Oocytes using Microrobot-Assisted Flow-Speed Control

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Akihiko Ichikawa

2013-06-01

Full Text Available In this study, we developed a microfluidic chip with a magnetically driven microrobot for oocyte enucleation. A microfluidic system was specially designed for enucleation, and the microrobot actively controls the local flow-speed distribution in the microfluidic chip. The microrobot can adjust fluid resistances in a channel and can open or close the channel to control the flow distribution. Analytical modeling was conducted to control the fluid speed distribution using the microrobot, and the model was experimentally validated. The novelties of the developed microfluidic system are as follows: (1 the cutting speed improved significantly owing to the local fluid flow control; (2 the cutting volume of the oocyte can be adjusted so that the oocyte undergoes less damage; and (3 the nucleus can be removed properly using the combination of a microrobot and hydrodynamic forces. Using this device, we achieved a minimally invasive enucleation process. The average enucleation time was 2.5 s and the average removal volume ratio was 20%. The proposed new system has the advantages of better operation speed, greater cutting precision, and potential for repeatable enucleation.

Efficiency of particle swarm optimization applied on fuzzy logic DC motor speed control

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Allaoua Boumediene

2008-01-01

Full Text Available This paper presents the application of Fuzzy Logic for DC motor speed control using Particle Swarm Optimization (PSO. Firstly, the controller designed according to Fuzzy Logic rules is such that the systems are fundamentally robust. Secondly, the Fuzzy Logic controller (FLC used earlier was optimized with PSO so as to obtain optimal adjustment of the membership functions only. Finally, the FLC is completely optimized by Swarm Intelligence Algorithms. Digital simulation results demonstrate that in comparison with the FLC the designed FLC-PSO speed controller obtains better dynamic behavior and superior performance of the DC motor, as well as perfect speed tracking with no overshoot.

Speed and surge control for a lower order centrifugal compressor model

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Jan T. Gravdahl

1998-01-01

Full Text Available A model of a variable speed centrifugal compression system is presented. The model is based on the work of Greitzer (1976, but the compressor characteristic is developed by modelling the losses in the compressor. For surge control, a close coupled valve is employed. This valve is placed immediately downstream of the compressor, and the pressure drop over the valve is used as the control variable. This makes it possible to manipulate the shape of the equivalent compressor, consisting of compressor and valve. The speed of the compressor is controlled with a PI-controller. Semi-global exponential stability of the model with the proposed controllers is proven by the use of Lyapunovs theorem.

Practical use of the amplitude and phase modulation of a high-power RF pulse via feed-forward control

International Nuclear Information System (INIS)

Kawase, Keigo; Kato, Ryukou; Irizawa, Akinori; Isoyama, Goro; Kashiwagi, Shigeru

2013-01-01

A new feed-forward control system to precisely control the amplitude and phase of the pulsed RF power in an electron linear accelerator (linac) is developed to make the accelerating field constant. Fast variations and ripples in the amplitude and phase in the RF pulses are compensated by modulating the amplitude and phase in the low-level system with a variable attenuator and phase shifter. The system is innovated the overdrive technique, which is commonly used in analog circuits, to speed up the slow response of the phase shifter, while the control signals are digitally processed; thus, the method is a hybrid of analog and digital techniques. By using the new control system, we find that the peak-to-peak variations in the amplitude and phase are reduced from 11.6% to 0.4% and from 6.1 degrees to 0.3 degrees, respectively, in 7.6-μs-long RF pulses for the L-band electron linac at Osaka University. (author)

Overall control strategy of variable speed doubly-fed induction generator wind turbine

DEFF Research Database (Denmark)

Hansen, A.D.; Iov, F.; Sørensen, Poul Ejnar

2004-01-01

The variable speed doubly-fed induction generator wind turbine is today the most widely used concept. The paper presents an overall control system of the variable speed DFIG wind turbine, with focus on the control strategies and algorithms applied at each hierarchical control level of the wind tu......-fed induction generator is implemented in the dynamic power system simulation tool DIgSILENT. Simulation results are performed and analyzed in different normal operating conditions....

Effects of walking speed on the step-by-step control of step width.

Science.gov (United States)

Stimpson, Katy H; Heitkamp, Lauren N; Horne, Joscelyn S; Dean, Jesse C

2018-02-08

Young, healthy adults walking at typical preferred speeds use step-by-step adjustments of step width to appropriately redirect their center of mass motion and ensure mediolateral stability. However, it is presently unclear whether this control strategy is retained when walking at the slower speeds preferred by many clinical populations. We investigated whether the typical stabilization strategy is influenced by walking speed. Twelve young, neurologically intact participants walked on a treadmill at a range of prescribed speeds (0.2-1.2 m/s). The mediolateral stabilization strategy was quantified as the proportion of step width variance predicted by the mechanical state of the pelvis throughout a step (calculated as R 2 magnitude from a multiple linear regression). Our ability to accurately predict the upcoming step width increased over the course of a step. The strength of the relationship between step width and pelvis mechanics at the start of a step was reduced at slower speeds. However, these speed-dependent differences largely disappeared by the end of a step, other than at the slowest walking speed (0.2 m/s). These results suggest that mechanics-dependent adjustments in step width are a consistent component of healthy gait across speeds and contexts. However, slower walking speeds may ease this control by allowing mediolateral repositioning of the swing leg to occur later in a step, thus encouraging slower walking among clinical populations with limited sensorimotor control. Published by Elsevier Ltd.

Digital Speed Cascade Control, using Scilab / Xcos Environment

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Petru Chioncel

2016-10-01

Full Text Available This paper presents an application of digital cascade control implemented in Scilab / Xcos environment, using a P type regulator for the position adjustment circuit, a PI controller for the speed circuit adjustment; the current respectively moments control circuits are rendered by elements of PT1 type. On this basis the program is done in Scilab and the related signal block diagram implemented in Xcos; through simulation, the step response of the system is analyzed for different sampling times.

Spatial layout affects speed discrimination

Science.gov (United States)

Verghese, P.; Stone, L. S.

1997-01-01

We address a surprising result in a previous study of speed discrimination with multiple moving gratings: discrimination thresholds decreased when the number of stimuli was increased, but remained unchanged when the area of a single stimulus was increased [Verghese & Stone (1995). Vision Research, 35, 2811-2823]. In this study, we manipulated the spatial- and phase relationship between multiple grating patches to determine their effect on speed discrimination thresholds. In a fusion experiment, we merged multiple stimulus patches, in stages, into a single patch. Thresholds increased as the patches were brought closer and their phase relationship was adjusted to be consistent with a single patch. Thresholds increased further still as these patches were fused into a single patch. In a fission experiment, we divided a single large patch into multiple patches by superimposing a cross with luminance equal to that of the background. Thresholds decreased as the large patch was divided into quadrants and decreased further as the quadrants were maximally separated. However, when the cross luminance was darker than the background, it was perceived as an occluder and thresholds, on average, were unchanged from that for the single large patch. A control experiment shows that the observed trend in discrimination thresholds is not due to the differences in perceived speed of the stimuli. These results suggest that the parsing of the visual image into entities affects the combination of speed information across space, and that each discrete entity effectively provides a single independent estimate of speed.

Two-phase strategy of neural control for planar reaching movements: I. XY coordination variability and its relation to end-point variability.

Science.gov (United States)

Rand, Miya K; Shimansky, Yury P

2013-03-01

A quantitative model of optimal transport-aperture coordination (TAC) during reach-to-grasp movements has been developed in our previous studies. The utilization of that model for data analysis allowed, for the first time, to examine the phase dependence of the precision demand specified by the CNS for neurocomputational information processing during an ongoing movement. It was shown that the CNS utilizes a two-phase strategy for movement control. That strategy consists of reducing the precision demand for neural computations during the initial phase, which decreases the cost of information processing at the expense of lower extent of control optimality. To successfully grasp the target object, the CNS increases precision demand during the final phase, resulting in higher extent of control optimality. In the present study, we generalized the model of optimal TAC to a model of optimal coordination between X and Y components of point-to-point planar movements (XYC). We investigated whether the CNS uses the two-phase control strategy for controlling those movements, and how the strategy parameters depend on the prescribed movement speed, movement amplitude and the size of the target area. The results indeed revealed a substantial similarity between the CNS's regulation of TAC and XYC. First, the variability of XYC within individual trials was minimal, meaning that execution noise during the movement was insignificant. Second, the inter-trial variability of XYC was considerable during the majority of the movement time, meaning that the precision demand for information processing was lowered, which is characteristic for the initial phase. That variability significantly decreased, indicating higher extent of control optimality, during the shorter final movement phase. The final phase was the longest (shortest) under the most (least) challenging combination of speed and accuracy requirements, fully consistent with the concept of the two-phase control strategy. This paper

Neuron-Adaptive PID Based Speed Control of SCSG Wind Turbine System

Directory of Open Access Journals (Sweden)

Shan Zuo

2014-01-01

Full Text Available In searching for methods to increase the power capacity of wind power generation system, superconducting synchronous generator (SCSG has appeared to be an attractive candidate to develop large-scale wind turbine due to its high energy density and unprecedented advantages in weight and size. In this paper, a high-temperature superconducting technology based large-scale wind turbine is considered and its physical structure and characteristics are analyzed. A simple yet effective single neuron-adaptive PID control scheme with Delta learning mechanism is proposed for the speed control of SCSG based wind power system, in which the RBF neural network (NN is employed to estimate the uncertain but continuous functions. Compared with the conventional PID control method, the simulation results of the proposed approach show a better performance in tracking the wind speed and maintaining a stable tip-speed ratio, therefore, achieving the maximum wind energy utilization.

Implementation of a Fuzzy Logic Speed Controller for a Permanent ...

African Journals Online (AJOL)

In this paper DC motor control models were mathematically extracted and implemented using fuzzy logic speed controller. All control systems suffer from problems related to undesirable overshoot, longer settling times and vibrations while going from one state to another. To overcome the maximum overshoot, fuzzy logic ...

DAC with LQR Control Design for Pitch Regulated Variable Speed Wind Turbine

DEFF Research Database (Denmark)

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

2014-01-01

Disturbance Accommodation Control (DAC) is used to model and simulate a system with known disturbance waveform. This paper presents a control scheme to mitigate the effect of disturbances by using collective pitch control for the aboverated wind speed (Region III) for a variable speed wind turbine....... We have used Linear Quadratic Regulator (LQR) to obtain full state feedback gain, disturbance feedback gain is calculated independently and then estimator gain is achieved by poleplacement technique in the DAC augmented plant model. The reduced order model (two-mass model) of wind turbine is used...... and 5MW National Renewable Energy Laboratory (NREL) wind turbine is used in this research. We have shown comparison of results relating to pitch angle, drive train torsion and generator speed obtained by a PID controller and DAC. Simulations are performed in MATLAB/Simulink. The results are compared...

Neural control and modulation of swimming speed in the larval zebrafish.

Science.gov (United States)

Severi, Kristen E; Portugues, Ruben; Marques, João C; O'Malley, Donald M; Orger, Michael B; Engert, Florian

2014-08-06

Vertebrate locomotion at different speeds is driven by descending excitatory connections to central pattern generators in the spinal cord. To investigate how these inputs determine locomotor kinematics, we used whole-field visual motion to drive zebrafish to swim at different speeds. Larvae match the stimulus speed by utilizing more locomotor events, or modifying kinematic parameters such as the duration and speed of swimming bouts, the tail-beat frequency, and the choice of gait. We used laser ablations, electrical stimulation, and activity recordings in descending neurons of the nucleus of the medial longitudinal fasciculus (nMLF) to dissect their contribution to controlling forward movement. We found that the activity of single identified neurons within the nMLF is correlated with locomotor kinematics, and modulates both the duration and oscillation frequency of tail movements. By identifying the contribution of individual supraspinal circuit elements to locomotion kinematics, we build a better understanding of how the brain controls movement. Copyright © 2014 Elsevier Inc. All rights reserved.

HPOTP low-speed flexible rotor balancing, phase 1

Science.gov (United States)

Giordano, J.; Zorzi, E.

1985-01-01

A method was developed that shows promise in overcoming many balancing limitations. This method establishes one or more windows for low speed, out-of-housing balancing of flexible rotors. These windows are regions of speed and support flexibility where two conditions are simultaneously fulfilled. First, the rotor system behaves flexibly; therefore, there is separation among balance planes. Second, the response due to balance weights is large enough to reliably measure. The analytic formulation of the low-speed flexible rotor balancing method is described. The results of proof-of-principle tests conducted under the program are presented. Based on this effort, it is concluded that low speed flexible rotor balancing is a viable technology. In particular, the method can be used to balance a rotor bearing system at low speed which results in smooth operation above more than one bending critical speed. Furthermore, this balancing methodology is applicable to SSME turbopump rotors.

Low Speed Control for Automatic Welding

Science.gov (United States)

Iceland, W. E.

1982-01-01

Amplifier module allows rotating positioner of automatic welding machine to operate at speeds below normal range. Low speeds are precisely regulated by a servomechanism as are normal-range speeds. Addition of module to standard welding machine makes it unnecessary to purchase new equipment for low-speed welding.

The SAHR Setup-Controlling Hopping Speed and Height Using a Single Actuator

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N. Cherouvim

2008-01-01

Full Text Available In this paper we present and experimentally validate a control method for regulating both the forward speed and the apex height of a one-legged hopping robot, using only a single actuator. The control method is based on a dynamic model of the hopping robot and makes use of the dynamic coupling of the vertical and forward motions of the robot. The control is applied first to a simulated model of the robot and shown to track a desired forward robot speed and a desired apex height. Then the SAHR (single actuator hopping robot hardware is introduced and is used as an experimental platform with which to evaluate the performance of the control method. The control method is applied to the physical setup and is shown to lead to a stable hopping gait with a desired forward speed and apex height, despite the unmodelled disturbances met on the laboratory floor.

A Rotor Flux and Speed Observer for Sensorless Single-Phase Induction Motor Applications

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Massimo Caruso

2012-01-01

Full Text Available It is usual to find single-phase induction motor (SPIM in several house, office, shopping, farm, and industry applications, which are become each time more sophisticated and requiring the development of efficient alternatives to improve the operational performance of this machine. Although the rotor flux and rotational speed are essential variables in order to optimize the operation of a SPIM, the use of conventional sensors to measure them is not a viable option. Thus, the adoption of sensorless strategies is the more reasonable proposal for these cases. This paper presents a rotor flux and rotational speed observer for sensorless applications involving SPIMs. Computer simulations and the experimental results are used to verify the performance of the proposed observer.

Simultaneous two-phase flow measurement of spray mixing process by means of high-speed two-color PIV

International Nuclear Information System (INIS)

Zhang, Ming; Xu, Min; Hung, David L S

2014-01-01

In this article, a novel high-speed two-color PIV optical diagnostic technique has been developed and applied to simultaneously measure the velocity flow-fields of a multi-hole spark-ignition direct injection (SIDI) fuel injector spray and its ambient gas in a high-pressure constant volume chamber. To allow for the phase discrimination between the fuel droplets and ambient gas, a special tracer-filter system was designed. Fluorescent seeding particles with Sauter mean diameter (SMD) of 4.8 µm were used to trace the gas inside the chamber. With a single high-speed Nd:YLF laser sheet (527 nm) as the incident light source, the Mie-scattering signal marked the phase of the fuel spray, while the fluorescent signal generated from the seeding particles tracked the phase of ambient gas. A high-speed camera, with an image-doubler (mounted in front of the camera lens) that divided the camera pixels into two parts focusing on the same field of view, was used to collect the Mie-scattering signal and LIF (laser induced fluorescence) signal simultaneously with two carefully selected optical filters. To accommodate the large dynamic range of velocities in the two phases (1–2 orders of magnitude difference), two separation times (dt) were introduced. This technique was successfully applied to the liquid spray and ambient gas two-phase flow measurement. The measurement accuracy was compared with those from LDV (laser Doppler velocimetry) measurement and good agreement was obtained. Ambient gas motion surrounding the fuel spray was investigated and characterized into three zones. The momentum transfer process between the fuel spray and ambient gas in each zone was analyzed. The two-phase flow interaction under various superheated conditions was investigated. A strengthened momentum transfer from the liquid spray to the ambient was observed with increased superheat degree. (paper)

IMITATION MODEL OF A HIGH-SPEED INDUCTION MOTOR WITH FREQUENCY CONTROL

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V. E. Pliugin

2017-12-01

Full Text Available Purpose. To develop the imitation model of the frequency converter controlled high-speed induction motor with a squirrel-cage rotor in order to determine reasons causes electric motor vibrations and noises in starting modes. Methodology. We have applied the mathematical simulation of electromagnetic field in transient mode and imported obtained field model as an independent object in frequency converter circuit. We have correlated the simulated result with the experimental data obtained by means of the PID regulator factors. Results. We have made the simulation model of the high-speed induction motor with a squirrel-cage rotor speed control in AnsysRMxprt, Ansys Maxwell and Ansys Simplorer, approximated to their physical prototype. We have made models modifications allows to provide high-performance computing (HPC in dedicated server and computer cluster to reduce the simulation time. We have obtained motor characteristics in starting and rated modes. This allows to make recommendations on determination of high-speed electric motor optimal deign, having minimum indexes of vibrations and noises. Originality. For the first time, we have carried out the integrated research of induction motor using simultaneously simulation models both in Ansys Maxwell (2D field model and in Ansys Simplorer (transient circuit model with the control low realization for the motor soft start. For the first time the correlation between stator and rotor slots, allows to obtain minimal vibrations and noises, was defined. Practical value. We have tested manufactured high-speed motor based on the performed calculation. The experimental studies have confirmed the adequacy of the model, which allows designing such motors for new high-speed construction, and upgrade the existing ones.

High speed reaction wheels for satellite attitude control and energy storage

Science.gov (United States)

Studer, P.; Rodriguez, E.

1985-01-01

The combination of spacecraft attitude control and energy storage (ACES) functions in common hardware, to synergistically maintain three-axis attitude control while supplying electrical power during earth orbital eclipses, allows the generation of control torques by high rotating speed wheels that react against the spacecraft structure via a high efficiency bidirectional energy conversion motor/generator. An ACES system encompasses a minimum of four wheels, controlling power and the three torque vectors. Attention is given to the realization of such a system with composite flywheel rotors that yield high energy density, magnetic suspension technology yielding low losses at high rotational speeds, and an ironless armature permanent magnet motor/generator yielding high energy conversion efficiency.

Control of variable speed variable pitch wind turbine based on a disturbance observer

Science.gov (United States)

Ren, Haijun; Lei, Xin

2017-11-01

In this paper, a novel sliding mode controller based on disturbance observer (DOB) to optimize the efficiency of variable speed variable pitch (VSVP) wind turbine is developed and analyzed. Due to the highly nonlinearity of the VSVP system, the model is linearly processed to obtain the state space model of the system. Then, a conventional sliding mode controller is designed and a DOB is added to estimate wind speed. The proposed control strategy can successfully deal with the random nature of wind speed, the nonlinearity of VSVP system, the uncertainty of parameters and external disturbance. Via adding the observer to the sliding mode controller, it can greatly reduce the chattering produced by the sliding mode switching gain. The simulation results show that the proposed control system has the effectiveness and robustness.

Effect of Performance Speed on Trunk Movement Control During the Curl-Up Exercise

Directory of Open Access Journals (Sweden)

Barbado David

2015-06-01

Full Text Available Trunk exercise speed has significant effects on neuro-mechanical demands; however, the influence of a variety of exercise speeds on motor control of the trunk displacement remains unknown. The aim of this study was to assess the effect of performance speed on trunk motion control during the curl-up exercise by analyzing the kinematic variance about the sagittal trajectory. Seventeen subjects volunteered to perform curl-ups at different cadences controlled by a metronome. Standard deviation (SD and range (RG of shoulder girdle medial-lateral displacement (SGML and detrended fluctuation analysis (DFA of SGML were calculated to examine linear variability and long range autocorrelation of medial-lateral upper trunk displacements, respectively. In addition, SD, RG and DFA of centre of pressure medial-lateral displacement (COPML were performed to analyze the behavior of the motor system while controlling trunk displacement. Although SD and RG of COPML increased as speed increased, the curl-up cadence did not have significant effects on SD and RG of SGML. These results suggest that although high speed curl-ups challenged participants’ ability to carry out medial-lateral adjustments, an increase of performance speed did not modify the linear variability about the sagittal trajectory. Regarding DFA, the scaling exponent α of SGML and COPML was higher for the fastest movements, mainly in long term fluctuations. Therefore, to maintain the target trajectory, participants used different strategies depending on performance speed. This is to say, there were less trajectory changes when participants performed the fastest exercises.

Optical signal processing techniques and applications of optical phase modulation in high-speed communication systems

Science.gov (United States)

Deng, Ning

In recent years, optical phase modulation has attracted much research attention in the field of fiber optic communications. Compared with the traditional optical intensity-modulated signal, one of the main merits of the optical phase-modulated signal is the better transmission performance. For optical phase modulation, in spite of the comprehensive study of its transmission performance, only a little research has been carried out in terms of its functions, applications and signal processing for future optical networks. These issues are systematically investigated in this thesis. The research findings suggest that optical phase modulation and its signal processing can greatly facilitate flexible network functions and high bandwidth which can be enjoyed by end users. In the thesis, the most important physical-layer technology, signal processing and multiplexing, are investigated with optical phase-modulated signals. Novel and advantageous signal processing and multiplexing approaches are proposed and studied. Experimental investigations are also reported and discussed in the thesis. Optical time-division multiplexing and demultiplexing. With the ever-increasing demand on communication bandwidth, optical time division multiplexing (OTDM) is an effective approach to upgrade the capacity of each wavelength channel in current optical systems. OTDM multiplexing can be simply realized, however, the demultiplexing requires relatively complicated signal processing and stringent timing control, and thus hinders its practicability. To tackle this problem, in this thesis a new OTDM scheme with hybrid DPSK and OOK signals is proposed. Experimental investigation shows this scheme can greatly enhance the demultiplexing timing misalignment and improve the demultiplexing performance, and thus make OTDM more practical and cost effective. All-optical signal processing. In current and future optical communication systems and networks, the data rate per wavelength has been approaching

Direct Torque Control System for Permanent Magnet Synchronous Machine with Fuzzy Speed Pi Regulator

Science.gov (United States)

Nabti, K.; Abed, K.; Benalla, H.

2008-06-01

The Permanent Magnet Synchronous Machine (PMSM) speed regulation with a conventional PI regulator reduces the speed control precision, increase the torque fluctuation, and consequentially low performances of the whole system. With utilisation of fuzzy logic method, this paper presents the self adaptation of conventional PI regulator parameters Kp and Ki (proportional and integral coefficients respectively), using to regulate the speed in Direct Torque Control strategy (DTC). The ripples of both torque and flux are reduced remarkable, small overshooting and good dynamic of the speed and torque. Simulation results verify the proposed method validity.

Modified Direct Torque Control of Three-Phase Induction Motor Drives with Low Ripple in Flux and Torque

Directory of Open Access Journals (Sweden)

Vinay KUMAR

2011-06-01

Full Text Available This paper proposes an algorithm for direct flux and torque controlled three phase induction motor drive systems. This method is based on control of slip speed and decoupled between amplitude and angle of reference stator flux for determining required stator voltage vector. In this proposes model, integrator unit is not required to generate the reference stator flux angle for calculating required stator voltage vector, hence it eliminates the initial values problems in real time. Within the given sampling time, flux as well as torque errors are controlled by stator voltage vector which is evaluated from reference stator flux. The direct torque control is achieved by reference stator flux angle which is generates from instantaneous slip speed angular frequency and stator flux angular frequency. The amplitude of the reference stator flux is kept constant at rated value. This technique gives better performance in three-phase induction motor than conventional technique. Simulation results for 3hp induction motor drive, for both proposed and conventional techniques, are presented and compared. From the results it is found that the stator current, flux linkage and torque ripples are decreased with proposed technique.

Speed control of an induction motor by 6-switched 3-level inverter

Directory of Open Access Journals (Sweden)

Saygin Ali

2017-12-01

Full Text Available This paper presents speed control analysis of an induction motor by a 6-switched 3-level inverter. In the analysis of topology, the study used the field oriented control technique which is widely used in the literature, easy and stable for operating systems. The field weaking technique was used for speeds exceeding nominal speed to reduce magnetic saturation and thermal losses. At the end of the process, it was observed to increase motor torque and inverter efficiency. Instead of using 12 switches in conventional 3-level inverters, 6 switches are used in this topology. Reduced number of switches is the greatest contribution of this study.

Speed control of an induction motor by 6-switched 3-level inverter

Science.gov (United States)

Saygin, Ali; Kerem, Alper

2017-12-01

This paper presents speed control analysis of an induction motor by a 6-switched 3-level inverter. In the analysis of topology, the study used the field oriented control technique which is widely used in the literature, easy and stable for operating systems. The field weaking technique was used for speeds exceeding nominal speed to reduce magnetic saturation and thermal losses. At the end of the process, it was observed to increase motor torque and inverter efficiency. Instead of using 12 switches in conventional 3-level inverters, 6 switches are used in this topology. Reduced number of switches is the greatest contribution of this study.

Behavioural system identification of visual flight speed control in Drosophila melanogaster.

Science.gov (United States)

Rohrseitz, Nicola; Fry, Steven N

2011-02-06

Behavioural control in many animals involves complex mechanisms with intricate sensory-motor feedback loops. Modelling allows functional aspects to be captured without relying on a description of the underlying complex, and often unknown, mechanisms. A wide range of engineering techniques are available for modelling, but their ability to describe time-continuous processes is rarely exploited to describe sensory-motor control mechanisms in biological systems. We performed a system identification of visual flight speed control in the fruitfly Drosophila, based on an extensive dataset of open-loop responses previously measured under free flight conditions. We identified a second-order under-damped control model with just six free parameters that well describes both the transient and steady-state characteristics of the open-loop data. We then used the identified control model to predict flight speed responses after a visual perturbation under closed-loop conditions and validated the model with behavioural measurements performed in free-flying flies under the same closed-loop conditions. Our system identification of the fruitfly's flight speed response uncovers the high-level control strategy of a fundamental flight control reflex without depending on assumptions about the underlying physiological mechanisms. The results are relevant for future investigations of the underlying neuromotor processing mechanisms, as well as for the design of biomimetic robots, such as micro-air vehicles.

Design of Controller for Reducing In-Rush Current of Single-Phase Induction Motor

Energy Technology Data Exchange (ETDEWEB)

Park, Su Kang; Baek, Hyung Lae; Lee, Sang Il [Chosun University, Kwangju (Korea)

2001-05-01

During an AC motor's start-up accelerating period, a large amount of current is required to reach to the rating speed. This is called in-rush current. This peak in-rush current can be more than about several times the operating or steady-state current in the full load rating of the motor. In-rush current is present in both and electronic ballasts. The main area of concern is the tripping of circuit breaker and fuses which can affect electrical system components From this, we can see that the electrical power controllers will be rather concerned, since they have to supply the actual current necessary to start the motor. This paper presents a new method to reducing in-rush current and energy saving of the single-phase induction motor used in air-conditioner. It can be obtained that proposed system is low cost and small size as compared with other controller. Experiments are focused on a capacitor starting single-phase induction motor. The optimal power saving and in-rush current limiting by phase angle control are verified by experimental results. Also, auxiliary winding was controlled by electronic starting switch. (author). 10 refs., 13 figs., 2 tabs.

Two wheel speed robust sliding mode control for electric vehicle drive

Directory of Open Access Journals (Sweden)

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.

Advanced high speed X-ray CT scanner for measurement and visualization of multi-phase flow

International Nuclear Information System (INIS)

Hori, Keiichi; Fujimoto, Tetsuro; Kawanishi, Kohei; Nishikawa, Hideo

1998-01-01

The development of an ultra-fast X-ray computed tomography (CT) scanner has been performed. The object of interest is in a transient or unsettled state, which makes the conventional CT scanner inappropriate. A concept of electrical switching of electron beam of X-ray generation unit is adopted to reduce the scanning time instead of a mechanical motion adopted by a conventional CT scanner. The mechanical motion is a major obstacle to improve the scanning speed. A prototype system with a scanning time of 3.6 milliseconds was developed at first. And, the feasibility was confirmed to measure the dynamic events of two-phase flow. However, faster scanning speed is generally required for the practical use in the thermalhydraulics research field. Therefore, the development of advanced type has been performed. This advanced type can operate under the scanning time of 0.5 milliseconds and is applicable for the measurement of the multi-phase flow with velocity up to 4-5 m/s. (author)

Power inverter implementing phase skipping control

Science.gov (United States)

Somani, Utsav; Amirahmadi, Ahmadreza; Jourdan, Charles; Batarseh, Issa

2016-10-18

A power inverter includes a DC/AC inverter having first, second and third phase circuitry coupled to receive power from a power source. A controller is coupled to a driver for each of the first, second and third phase circuitry (control input drivers). The controller includes an associated memory storing a phase skipping control algorithm, wherein the controller is coupled to receive updating information including a power level generated by the power source. The drivers are coupled to control inputs of the first, second and third phase circuitry, where the drivers are configured for receiving phase skipping control signals from the controller and outputting mode selection signals configured to dynamically select an operating mode for the DC/AC inverter from a Normal Control operation and a Phase Skipping Control operation which have different power injection patterns through the first, second and third phase circuitry depending upon the power level.

75 FR 37453 - Notice of Issuance of Final Determination Concerning Dimmer and Fan Speed Switch Controls

Science.gov (United States)

2010-06-29

... Determination Concerning Dimmer and Fan Speed Switch Controls AGENCY: U.S. Customs and Border Protection... country of origin of certain dimmer and fan speed switch controls which may be offered to the United... determination CBP concluded that Mexico is the country of origin of the dimmer and fan speed switch controls for...

High speed ultrasonic system to measure bubbles velocities in a horizontal two-phase flow

International Nuclear Information System (INIS)

Cunha Filho, Jurandyr S.; Jian Su; Farias, Marcos S.; Faccini, Jose L.H.; Lamy, Carlos A.

2009-01-01

In this work, a non invasive technique consisting of a high speed ultrasonic multitransducer pulse-echo system was developed to characterize gas-liquid two-phase flow parameters that are important in the study of the primary refrigeration circuit of nuclear reactors. The high speed ultrasonic system consists of two transducers (10 MHz/φ 6.35 mm), a generator/multiplexer board, and software that selects and has a data acquisition system of the ultrasonic signals. The resolutions of the system and the pulse time generated from each transducer are, respectively, 10 ns and 1.06 ms. The system initially was used in the local instantaneous measurement of gas-liquid interface in a circular horizontal pipe test section made of a 5 m long stainless steel pipe of 51.2 mm inner diameter, where the elongated bubbles velocity was measured (Taylor bubbles). The results show that the high speed ultrasonic pulse-echo system provides good results for the determination of elongated bubbles velocities. (author)

A nonlinear model predictive control formulation for obstacle avoidance in high-speed autonomous ground vehicles in unstructured environments

Science.gov (United States)

Liu, Jiechao; Jayakumar, Paramsothy; Stein, Jeffrey L.; Ersal, Tulga

2018-06-01

This paper presents a nonlinear model predictive control (MPC) formulation for obstacle avoidance in high-speed, large-size autono-mous ground vehicles (AGVs) with high centre of gravity (CoG) that operate in unstructured environments, such as military vehicles. The term 'unstructured' in this context denotes that there are no lanes or traffic rules to follow. Existing MPC formulations for passenger vehicles in structured environments do not readily apply to this context. Thus, a new nonlinear MPC formulation is developed to navigate an AGV from its initial position to a target position at high-speed safely. First, a new cost function formulation is used that aims to find the shortest path to the target position, since no reference trajectory exists in unstructured environments. Second, a region partitioning approach is used in conjunction with a multi-phase optimal control formulation to accommodate the complicated forms the obstacle-free region can assume due to the presence of multiple obstacles in the prediction horizon in an unstructured environment. Third, the no-wheel-lift-off condition, which is the major dynamical safety concern for high-speed, high-CoG AGVs, is ensured by limiting the steering angle within a range obtained offline using a 14 degrees-of-freedom vehicle dynamics model. Thus, a safe, high-speed navigation is enabled in an unstructured environment. Simulations of an AGV approaching multiple obstacles are provided to demonstrate the effectiveness of the algorithm.

The Effect of Shoe Insole Stiffness on Leg Stiffness during Stance Phase of Running in Two Different Speeds ‎among Active Men

Directory of Open Access Journals (Sweden)

Zeinab Tazike-Lemeski

2016-08-01

Full Text Available Introduction: The effect of shoe insoles with different characteristics and in different running speeds on lower-limb stiffness is still ‎controversial. The aim of this study was to investigate the effect of two types of insoles (soft and semi-rigid in two ‎different running speeds on leg stiffness during stance phase of running among active men.‎ Materials and Methods: ‎15 male students without any background of lower extremity injury were selected. Subjects were asked to run with ‎two controlled velocities of 3.0 ± 0.2 and 5.0 ± 0.1 m/s in control and insole conditions (soft and semi-rigid on a ‎force plate, placed on the middle of 15-meter runway. The cinematics and cinetics of motion were measured and ‎calculated using 5 video cameras and one force plate. The leg stiffness was achieved via dividing the vertical ‎ground reaction force by leg compression. Two-factor repeated measures ANOVA was used to test the hypothesis at ‎the significance level of P £ 0.050.‎ Results: There was a significant difference between the two types of insoles on leg stiffness. In fact, semi-rigid insole significantly increased leg stiffness (P < 0.001. However, this discrepancy was not related to the running speed (P = 0.999. In addition, there was no significant difference between the two different speeds on leg stiffness (P = 0.632. Conclusion: It seems that the increase in shoe insole stiffness may increase the leg stiffness. Furthermore, the effect of insole ‎stiffness is not related to the running speed, and leg stiffness will remains constant in low to medium running speeds.‎

A disturbance decoupling nonlinear control law for variable speed wind turbines

DEFF Research Database (Denmark)

Thomsen, Sven Creutz; Poulsen, Niels Kjølstad

2007-01-01

This paper describes a nonlinear control law for controlling variable speed wind turbines using feedback linearization. The novel aspect of the control law is its ability to decouple the effect of wind fluctuations. Furthermore, the transformation to feedback linearizable coordinates is chosen...

MPPT Algorithm for Small Wind Systems based on Speed Control Strategy

Directory of Open Access Journals (Sweden)

Ciprian VLAD

2008-07-01

Full Text Available This paper presents experimental results of an autonomous low-power wind energy conversion system (WECS, based on a permanent-magnet synchronous generator (PMSG connected directly to the wind turbine. The purpose of this paper is to present an improving method for MPPT (Maximum Power Point Tracking algorithm based shaft rotational speed optimal control. The proposed method concern the variable delay compensation between measured wind speed from anemometer and wind shaft rotational speed proportional signal. Experimental results aiming to prove the efficiency of the proposed method are presented.

Induction motor IFOC based speed-controlled drive with asymptotic disturbance compensation

Directory of Open Access Journals (Sweden)

Stojić Đorđe M.

2012-01-01

Full Text Available This paper presents the design of digitally controlled speed electrical drive, with the asymptotic compensation of external disturbances, implemented by using the IFOC (Indirect Field Oriented Control torque controlled induction motor. The asymptotic disturbance compensation is achieved by using the DOB (Disturbance Observer with the IMP (Internal Model Principle. When compared to the existing IMP-based DOB solutions, in this paper the robust stability and disturbance compensation are improved by implementing the minimal order DOB filter. Also, the IMP-based DOB design is improved by employing the asymptotic compensation of all elemental or more complex external disturbances. The dynamic model of the IFOC torque electrical drive is, also, included in the speed-controller and DOB section design. The simulation and experimental measurements presented in the paper illustrate the effectiveness and robustness of the proposed control scheme.

Load speed regulation in compliant mechanical transmission systems using feedback and feedforward control actions.

Science.gov (United States)

Raul, P R; Dwivedula, R V; Pagilla, P R

2016-07-01

The problem of controlling the load speed of a mechanical transmission system consisting of a belt-pulley and gear-pair is considered. The system is modeled as two inertia (motor and load) connected by a compliant transmission. If the transmission is assumed to be rigid, then using either the motor or load speed feedback provides the same result. However, with transmission compliance, due to belts or long shafts, the stability characteristics and performance of the closed-loop system are quite different when either motor or load speed feedback is employed. We investigate motor and load speed feedback schemes by utilizing the singular perturbation method. We propose and discuss a control scheme that utilizes both motor and load speed feedback, and design an adaptive feedforward action to reject load torque disturbances. The control algorithms are implemented on an experimental platform that is typically used in roll-to-roll manufacturing and results are shown and discussed. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

A new on-chip all-digital three-phase full-bridge dc/ac power inverter with feedforward and frequency control techniques.

Science.gov (United States)

Chen, Jiann-Jong; Kung, Che-Min

2010-09-01

The communication speed between components is far from satisfactory. To achieve high speed, simple control system configuration, and low cost, a new on-chip all-digital three-phase dc/ac power inverter using feedforward and frequency control techniques is proposed. The controller of the proposed power inverter, called the shift register, consists of six-stage D-latch flip-flops with a goal of achieving low-power consumption and area efficiency. Variable frequency is achieved by controlling the clocks of the shift register. One advantage regarding the data signal (D) and the common clock (CK) is that, regardless of the phase difference between the two, all of the D-latch flip-flops are capable of delaying data by one CK period. To ensure stability, the frequency of CK must be six times higher than that of D. The operation frequency of the proposed power inverter ranges from 10 Hz to 2 MHz, and the maximum output loading current is 0.8 A. The prototype of the proposed circuit has been fabricated with TSMC 0.35 μm 2P4M CMOS processes. The total chip area is 2.333 x 1.698 mm2. The three-phase dc/ac power inverter is applicable in uninterrupted power supplies, cold cathode fluorescent lamps, and motors, because of its ability to convert the dc supply voltage into the three-phase ac power sources.

Speed control of diesel generator sets

International Nuclear Information System (INIS)

Jenzer, J.

1989-01-01

In some marine and stationary power plants, it is often of interest to be able to give some information about the dynamic behaviour of the engine when it is loaded according to a given programme: How well it reacts to the application of a step load and to a load rejection. What is the best speed governor type and its optimum parameter adjustment in order to satisfy the requested specification of maximum speed engine deviation and recovery time. How great is the influence of turbocharger options such as jet assist or waste gate on the dynamic behaviour of the plant. Such kinds of questions occur for all stand-by power stations and in marine installations where the engine is submitted to very large load variations in the form of steps, ramps or any other load programme. The computer program GENERAT fully fulfils the aims described above. The comparison of measurements and simulation is good enough to allow us to use simulation as a means of predicting the dynamic behaviour of stationary power plant with four-stroke engines submitted to a given load programme. This program allows us also to determine the optimum generator inertia and to find the optimum governor parameters. The next step of development will be to model the turbocharger and supercharging method for two-stroke engines and some new digital speed controls and to rewrite the program with the help of the simulation package ACSL. This last point presents some advantages, as for example in large reduction of program maintenance and higher flexibility

Experimental Study of Low Speed Sensorless Control of PMSM Drive Using High Frequency Signal Injection

Directory of Open Access Journals (Sweden)

Jyoti Agrawal

2016-01-01

Full Text Available Conventional techniques for sensorless control of permanent magnet synchronous motor drive (PMSM, which requires information on rotor position, are reviewed, and recent developments in this area are introduced in this paper along with their inherent advantages and drawbacks. The paper presents an improved method for sensorless speed control of PMSM drive with emphasis placed on signal injection method. This signal injection method examines the control performance of sensorless PMSM drive by injecting signal externally and thereby sensing the rotor position. The main objective of this drive system is to have speed control at standstill and low speed regions. Several tests are carried out to demonstrate the ability of proposed models at different operating conditions with the help of simulation results in Matlab/Simulink environment. Simulation results confirm that the proposed sensorless control approach of PMSM can achieve high performance at standstill and low speeds but not at very high speeds. An experimental setup is implemented using a 1HP surface mounted (SM PMSM and DsPICDEM^TM MCHV-2 development board, to check the validity of simulation results.

Speed Sensorless Control of PMSM using Model Reference Adaptive System and RBFN

OpenAIRE

Wei Gao; Zhirong Guo

2013-01-01

In the speed sensorless vector control system, the amended method of estimating the rotor speed about model reference adaptive system (MRAS) based on radial basis function neural network (RBFN) for PMSM sensorless vector control system was presented. Based on the PI regulator, the radial basis function neural network which is more prominent learning efficiency and performance is combined with MRAS. The reference model and the adjust model are the PMSM itself and the PMSM current, respectively...

Explicit Generalized Predictive Control of Speed and Position of PMSM Drives

Czech Academy of Sciences Publication Activity Database

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: 7.168, year: 2016 http://library.utia.cas.cz/separaty/2016/AS/belda-0457259.pdf

Power system integration and control of variable speed wind turbines

Energy Technology Data Exchange (ETDEWEB)

Eek, Jarle

2009-12-15

A wind power plant is a highly dynamic system that dependent on the type of technology requires a number of automatic control loops. This research deals with modelling, control and analysis related to power system integration of variable speed, pitch controlled wind turbines. All turbine components have been modelled and implemented in the power system simulation program SIMPOW, and a description of the modelling approach for each component is given. The level of model detail relates to the classical modelling of power system components for power system stability studies, where low frequency oscillations are of special importance. The wind turbine model includes a simplified representation of the developed rotor torque and the thrust force based on C{sub p-} and C{sub t} characteristic curves. The mechanical system model represents the fundamental torsional mode and the first mode of blades and tower movements. Two generator technologies have been investigated. The doubly fed induction generator (DFIG) and the stator converter interfaced permanent magnet synchronous generator (PMSG). A simplified model of a 2 level voltage source converter is used for both machine types. The generator converter controllers have been given special attention. All model components are linearized for the purpose of control system design and power system interaction related to small signal stability analysis. Different control strategies discussed in the literature have been investigated with regard to power system interaction aspects. All control parameters are identified using the internal model control approach. The analysis is focused on three main areas: 1. Identification of low damped oscillatory modes. This is carried out by the establishment and discussion of wind turbine modelling. 2. Interaction between control loops. A systematic approach is presented in order to analyse the influence of control loops used in variable speed wind turbines. 3.Impact on power system performance

Direct Evidence for Vision-based Control of Flight Speed in Budgerigars.

Science.gov (United States)

Schiffner, Ingo; Srinivasan, Mandyam V

2015-06-05

We have investigated whether, and, if so, how birds use vision to regulate the speed of their flight. Budgerigars, Melopsittacus undulatus, were filmed in 3-D using high-speed video cameras as they flew along a 25 m tunnel in which stationary or moving vertically oriented black and white stripes were projected on the side walls. We found that the birds increased their flight speed when the stripes were moved in the birds' flight direction, but decreased it only marginally when the stripes were moved in the opposite direction. The results provide the first direct evidence that Budgerigars use cues based on optic flow, to regulate their flight speed. However, unlike the situation in flying insects, it appears that the control of flight speed in Budgerigars is direction-specific. It does not rely solely on cues derived from optic flow, but may also be determined by energy constraints.

Robust output feedback cruise control for high-speed train movement with uncertain parameters

International Nuclear Information System (INIS)

Li Shu-Kai; Yang Li-Xing; Li Ke-Ping

2015-01-01

In this paper, the robust output feedback cruise control for high-speed train movement with uncertain parameters is investigated. The dynamic of a high-speed train is modeled by a cascade of cars connected by flexible couplers, which is subject to rolling mechanical resistance, aerodynamic drag and wind gust. Based on Lyapunov’s stability theory, the sufficient condition for the existence of the robust output feedback cruise control law is given in terms of linear matrix inequalities (LMIs), under which the high-speed train tracks the desired speed, the relative spring displacement between the two neighboring cars is stable at the equilibrium state, and meanwhile a small prescribed H ∞ disturbance attenuation level is guaranteed. One numerical example is given to illustrate the effectiveness of the proposed methods. (paper)

Accurate calibration of steam turbine speed control system and its influence on primary regulation at electric grid

Energy Technology Data Exchange (ETDEWEB)

Irrazabal Bohorquez, Washington Orlando; Barbosa, Joao Roberto [Technological Institute of Aeronautics (ITA/CTA), Sao Jose dos Campos, SP (Brazil). Center for Reference on Gas Turbine and Energy], E-mail: barbosa@ita.br

2010-07-01

In an interconnected electric system there are two very important parameters: the field voltage and the frequency system. The frequency system is very important for the primary regulation of the electric grid. Each turbomachine actuating as generator interconnected to the grid has an automatic speed regulator to keep the rotational speed and mechanical power of the prime machine operating at the set conditions and stable frequency. The electric grid is a dynamical system and in every moment the power units are exposed to several types of disturbances, which cause unbalance of the mechanical power developed by prime machine and the consumed electric power at the grid. The steam turbine speed control system controls the turbine speed to support the electric grid primary frequency at the same time it controls the frequency of the prime machine. Using a mathematical model for the speed control system, the transfer functions were calculated, as well as the proportionality constants of each element of the steam turbine automatic speed regulator. Among other parameters, the droop characteristic of steam turbine and the dynamic characteristics of the automatic speed regulator elements were calculated. Another important result was the determination of the behavior of the speed control when disturbances occur with the improvement of the calibration precision of the control system. (author)

Model predictive control of a high speed switched reluctance generator system

NARCIS (Netherlands)

Marinkov, Sava; De Jager, Bram; Steinbuch, Maarten

2013-01-01

This paper presents a novel voltage control strategy for the high-speed operation of a Switched Reluctance Generator. It uses a linear Model Predictive Control law based on the average system model. The controller computes the DC-link current needed to achieve the tracking of a desired voltage

Solid state circuit controls direction, speed, and braking of dc motor

Science.gov (United States)

Hanna, M. F.

1966-01-01

Full-wave bridge rectifier circuit controls the direction, speed, and braking of a dc motor. Gating in the circuit of Silicon Controlled Rectifiers /SCRS/ controls output polarity and braking is provided by an SCR that is gated to short circuit the reverse voltage generated by reversal of motor rotation.

Analysis of Three-Phase Rectifier Systems with Controlled DC-Link Current Under Unbalanced Grids

DEFF Research Database (Denmark)

Kumar, Dinesh; Davari, Pooya; Zare, Firuz

2017-01-01

Voltage unbalance is the most common disturbance in distribution networks, which give undesirable effects on many grid connected power electronics systems including Adjustable Speed Drive (ASD). Severe voltage unbalance can force three-phase rectifiers into almost single-phase operation, which...... degrades the grid power quality and also imposes a significant negative impact on the ASD system. This major power quality issue affecting the conventional rectifiers can be attenuated by controlling the DC-link current based on an Electronic Inductor (EI) technique. The purpose of this digest...... is to analyze and compare the performance of an EI with a conventional three-phase rectifier under unbalanced grid conditions. Experimental and simulation results validate the proposed mathematical modelling. Further analysis and benchmarking will be provided in the final paper....

Potential electricity savings by variable speed control of compressor for air conditioning systems

Energy Technology Data Exchange (ETDEWEB)

Nasution, Henry [Bung Hatta University, Department of Mechanical Engineering, Faculty of Industrial Engineering, Padang, West Sumatera (Indonesia); Wan Hassan, Mat Nawi [Universiti Teknologi Malaysia, Faculty of Mechanical Engineering, Skudai, Johor Bahru-Darul Ta' zim (Malaysia)

2006-05-15

The potential of a variable-speed compressor running on a controller to provide enhanced load-matching capability, energy saving and thermal comfort for application in air-conditioning system is demonstrated. An air-conditioning system, originally operated on a constant speed mode, is retrofitted with an inverter and a PID controller. The system was installed to a thermal environmental room together with a data acquisition system to monitor energy consumption and temperature of the room. Measurements were taken 2 h daily at a time interval of 5 min for an on/off and an inverter variable-speed conditions. The results indicate that thermal comfort of the room together with energy saving can be obtained through a proper selection of K for the controller. At a temperature setting of 22 C, the energy saving for the system is estimated to reach 25.3% for PID controllers. (orig.)

A control strategy for induction motors fed from single phase supply

DEFF Research Database (Denmark)

Søndergård, Lars Møller

1993-01-01

It is often required that a three-phased asynchronous motor can run at variable speed, which makes it necessary to use a three-phase inverter driven from a DC-source. Today, most inverters are driven from the network using a simple diode bridge and an electrolytic capacitor. The problem with the ......It is often required that a three-phased asynchronous motor can run at variable speed, which makes it necessary to use a three-phase inverter driven from a DC-source. Today, most inverters are driven from the network using a simple diode bridge and an electrolytic capacitor. The problem...... with the simple diode bridge and the electrolytic capacitor is that current is only drawn for short periods, which gives rise to harmonic currents in the network. For small drive systems (motor+inverter), i.e. less than 1.5 kW, a single phase network outlet is often used. The author describes a method whereby...

Power Maximization Control of Variable Speed Wind Generation System Using Permanent Magnet Synchronous Generator

Science.gov (United States)

Morimoto, Shigeo; Nakamura, Tomohiko; Takeda, Yoji

This paper proposes the sensorless output power maximization control of the wind generation system. A permanent magnet synchronous generator (PMSG) is used as a variable speed generator in the proposed system. The generator torque is suitably controlled according to the generator speed and thus the power from a wind turbine settles down on the maximum power point by the proposed MPPT control method, where the information of wind velocity is not required. Moreover, the maximum available generated power is obtained by the optimum current vector control. The current vector of PMSG is optimally controlled according to the generator speed and the required torque in order to minimize the losses of PMSG considering the voltage and current constraints. The proposed wind power generation system can be achieved without mechanical sensors such as a wind velocity detector and a position sensor. Several experimental results show the effectiveness of the proposed control method.

Improved Fuzzy Logic based DTC of Induction machine for wide range of speed control using AI based controllers

Directory of Open Access Journals (Sweden)

H. Sudheer

2016-06-01

Full Text Available This paper presents improvements in Direct Torque control of induction motor using Fuzzy logic switching controller (FDTC. The conventional DTC (CDTC and FDTC drive performance is compared using Conventional PI, Fuzzy controller and Neural Network controllers. The major disadvantages of CDTC are high torque and flux ripples in steady state operation of the drive, inferior performance at low speed operation and variable switching frequency. The presence of hysteresis bands is the major reason for high torque and flux ripples in CDTC. In FDTC the hysteresis band and switching table are replaced by Fuzzy logic switching controller. Using fuzzy logic torque, stator flux space are divided into smaller subsections which results in precise and optimal selection of switching state to meet load torque. In high performance drives accurate tuning of PI speed controller is required. The conventional PI controller cannot adapt to the variation in model parameters. Artificial intelligence based fuzzy controller and neural network controller are compared with PI controller for both CDTC and FDTC of Induction machine. The proposed schemes are developed in Matlab/Simulink environment. Simulation results shows reduction in torque and flux ripples in FDTC and dynamic performance of the drive at low speeds and sudden change in load torque can be improved using Fuzzy logic controller compared to PI and neural network controller.

Development of super-synchronization speed control assembly for 2500 kW double-fed motor

International Nuclear Information System (INIS)

Li Huajun; Xuan Weimin; Peng Jianfei; Hu Haotian; Wang Shujing; Kang Li; Xu Lirong; Huang Zhaorong; Wang Xiaoping; Du Cang; Liu Ling

2007-01-01

The super-synchronization speed control assemblies for the two 2500 kW induction motors have been developed successfully in order to meet the need for toroidal field increasing in HL-2A tokamak. Based on the a.c./a.c. cycloconverter, the speed of each 2500 kW motor has been regulated by means of vector control technology for double-fed motor. The highest rotate speed of the two 80 MVA generator sets have been increased from 1488 rpm rated speed to 1650 rpm and the released energy of each generator set in one pulse discharge can reach 500 MJ. Therefore the toroidal field system is able to reach 2.8T for experiment. (authors)

Flicker Mitigation by Individual Pitch Control of Variable Speed Wind Turbines With DFIG

DEFF Research Database (Denmark)

Zhang, Yunqian; Chen, Zhe; Hu, Weihao

2014-01-01

generatorto investigate the flicker emission and mitigation issues. An individual pitch control (IPC) strategy is proposed to reduce the flicker emission at different wind speed conditions. The IPC scheme is proposed and the individual pitch controller is designed according to the generator active power...... and the azimuth angle of the wind turbine. The simulations are performed on the NREL (National Renewable Energy Laboratory) 1.5-MW upwind reference wind turbine model. Simulation results show that damping the generator active power by IPC is an effective means for flicker mitigation of variable speed wind......Due to the wind speed variation, wind shear and tower shadow effects, grid connected wind turbines are the sources of power fluctuations which may produce flicker during continuous operation. This paper presents a model of an MW-level variable-speed wind turbine with a doubly fed induction...

Gain-scheduled Linear Quadratic Control of Wind Turbines Operating at High Wind Speed

DEFF Research Database (Denmark)

Østergaard, Kasper Zinck; Stoustrup, Jakob; Brath, Per

2007-01-01

This paper addresses state estimation and linear quadratic (LQ) control of variable speed variable pitch wind turbines. On the basis of a nonlinear model of a wind turbine, a set of operating conditions is identified and a LQ controller is designed for each operating point. The controller gains...... are then interpolated linearly to get a control law for the entire operating envelope. A nonlinear state estimator is designed as a combination of two unscented Kalman filters and a linear disturbance estimator. The gain-scheduling variable (wind speed) is then calculated from the output of these state estimators...

Electric Drive Control with Rotor Resistance and Rotor Speed Observers Based on Fuzzy Logic

Directory of Open Access Journals (Sweden)

C. Ben Regaya

2014-01-01

Full Text Available Many scientific researchers have proposed the control of the induction motor without speed sensor. These methods have the disadvantage that the variation of the rotor resistance causes an error of estimating the motor speed. Thus, simultaneous estimation of the rotor resistance and the motor speed is required. In this paper, a scheme for estimating simultaneously the rotor resistance and the rotor speed of an induction motor using fuzzy logic has been developed. We present a method which is based on two adaptive observers using fuzzy logic without affecting each other and a simple algorithm in order to facilitate the determination of the optimal values of the controller gains. The control algorithm is proved by the simulation tests. The results analysis shows the characteristic robustness of the two observers of the proposed method even in the case of variation of the rotor resistance.

Design of a model predictive load-following controller by discrete optimization of control rod speed for PWRs

International Nuclear Information System (INIS)

Kim, Jae Hwan; Park, Soon Ho; Na, Man Gyun

2014-01-01

Highlights: • A model predictive controller for load-following operation was developed. • Genetic algorithm optimizes the five nonlinear discrete control rod speeds. • The boron concentration is adjusted with automatic adjustment logic. • The proposed controller reflects the realistic control rod drive mechanism movement. • The performance was confirmed to be satisfactory by simulation from BOC to EOC. - Abstract: Currently, most existing nuclear power plants alter the reactor power by adjusting the boron concentration in the coolant because it has a smaller effect on the reactor power distribution. Frequent control rod movements for load-following operation induce xenon-oscillation. Therefore, a controller that can subdue this phenomenon effectively is needed. At an APR1400 nuclear power plant which is a pressurized water reactor (PWR), the reactor power is controlled automatically using a Reactor Regulating System (RRS) but the power distribution is controlled manually by operators. Therefore, for APR+ nuclear power plants which is an improved version of APR1400 nuclear reactor, a new concept of a reactor controller is needed to control both the reactor power and power distribution automatically. The model predictive control (MPC) method is applicable to multiple-input multiple-output control, and can be applied for complex and nonlinear systems, such as the nuclear power plants. In this study, an MPC controller was developed by applying a genetic algorithm to optimize the discrete control rod speeds and by reflecting the realistic movement of the control rod drive mechanism that moves at only five discrete speeds. The performance of the proposed controller was confirmed to be satisfactory by simulating the load-following operation of an APR+ nuclear power plant through interface with KISPAC-1D code

Maritime routing and speed optimization with emission control areas

DEFF Research Database (Denmark)

Fagerholt, Kjetil; Gausel, Nora T.; Rakke, Jørgen G.

2015-01-01

a computational study on a number of realistic shipping routes in order to evaluate possible impacts on sailing paths and speeds, and hence fuel consumption and costs, from the ECA regulations. Moreover, the aim is to examine the implications for the society with regards to environmental effects. Comparisons...... of cases show that a likely effect of the regulations is that ship operators will often choose to sail longer distances to avoid sailing time within ECAs. Another effect is that they will sail at lower speeds within and higher speeds outside the ECAs in order to use less of the more expensive fuel. On some......Strict limits on the maximum sulphur content in fuel used by ships have recently been imposed in some Emission Control Areas (ECAs). In order to comply with these regulations many ship operators will switch to more expensive low-sulphur fuel when sailing inside ECAs. Since they are concerned about...

A Novel Neural Network Vector Control for Single-Phase Grid-Connected Converters with L, LC and LCL Filters

Directory of Open Access Journals (Sweden)

Xingang Fu

2016-04-01

Full Text Available This paper investigates a novel recurrent neural network (NN-based vector control approach for single-phase grid-connected converters (GCCs with L (inductor, LC (inductor-capacitor and LCL (inductor-capacitor-inductor filters and provides their comparison study with the conventional standard vector control method. A single neural network controller replaces two current-loop PI controllers, and the NN training approximates the optimal control for the single-phase GCC system. The Levenberg–Marquardt (LM algorithm was used to train the NN controller based on the complete system equations without any decoupling policies. The proposed NN approach can solve the decoupling problem associated with the conventional vector control methods for L, LC and LCL-filter-based single-phase GCCs. Both simulation study and hardware experiments demonstrate that the neural network vector controller shows much more improved performance than that of conventional vector controllers, including faster response speed and lower overshoot. Especially, NN vector control could achieve very good performance using low switch frequency. More importantly, the neural network vector controller is a damping free controller, which is generally required by a conventional vector controller for an LCL-filter-based single-phase grid-connected converter and, therefore, can overcome the inefficiency problem caused by damping policies.

Speed Sensorless Control of Permanent Magnet Synchronous Motors in Mine Electric Locomotive Drive

Directory of Open Access Journals (Sweden)

Yudong LI

2014-04-01

Full Text Available This paper presents a novel sensorless control method of permanent magnet synchronous motors a low speed based on a high-frequency voltage signal injection. The approach superimposes a persistent HF voltage signal into the estimated d-axis to get the rotor position error angle-related signal by detecting the corresponding voltage response and current response. Then the rotor position and motor speed are obtained. Theoretical analysis and simulation results demonstrate that the approach can achieve sensorless control of permanent magnet synchronous motors at zero and low speed, ensure good dynamic and static performances, and achieve effective control when applied to servo system. Finally, a test prototype system which used a digital signal processor and space vector pulse width modulation technology has been developed. Experimental results show that the system has better static, the effectiveness and dynamic performance of the adaptive test signals in a sensorless controlled surface-mounted permanent magnet synchronous machines.

A New Turbo-shaft Engine Control Law during Variable Rotor Speed Transient Process

Science.gov (United States)

Hua, Wei; Miao, Lizhen; Zhang, Haibo; Huang, Jinquan

2015-12-01

A closed-loop control law employing compressor guided vanes is firstly investigated to solve unacceptable fuel flow dynamic change in single fuel control for turbo-shaft engine here, especially for rotorcraft in variable rotor speed process. Based on an Augmented Linear Quadratic Regulator (ALQR) algorithm, a dual-input, single-output robust control scheme is proposed for a turbo-shaft engine, involving not only the closed loop adjustment of fuel flow but also that of compressor guided vanes. Furthermore, compared to single fuel control, some digital simulation cases using this new scheme about variable rotor speed have been implemented on the basis of an integrated system of helicopter and engine model. The results depict that the command tracking performance to the free turbine rotor speed can be asymptotically realized. Moreover, the fuel flow transient process has been significantly improved, and the fuel consumption has been dramatically cut down by more than 2% while keeping the helicopter level fight unchanged.

Two-phase strategy of controlling motor coordination determined by task performance optimality.

Science.gov (United States)

Shimansky, Yury P; Rand, Miya K

2013-02-01

A quantitative model of optimal coordination between hand transport and grip aperture has been derived in our previous studies of reach-to-grasp movements without utilizing explicit knowledge of the optimality criterion or motor plant dynamics. The model's utility for experimental data analysis has been demonstrated. Here we show how to generalize this model for a broad class of reaching-type, goal-directed movements. The model allows for measuring the variability of motor coordination and studying its dependence on movement phase. The experimentally found characteristics of that dependence imply that execution noise is low and does not affect motor coordination significantly. From those characteristics it is inferred that the cost of neural computations required for information acquisition and processing is included in the criterion of task performance optimality as a function of precision demand for state estimation and decision making. The precision demand is an additional optimized control variable that regulates the amount of neurocomputational resources activated dynamically. It is shown that an optimal control strategy in this case comprises two different phases. During the initial phase, the cost of neural computations is significantly reduced at the expense of reducing the demand for their precision, which results in speed-accuracy tradeoff violation and significant inter-trial variability of motor coordination. During the final phase, neural computations and thus motor coordination are considerably more precise to reduce the cost of errors in making a contact with the target object. The generality of the optimal coordination model and the two-phase control strategy is illustrated on several diverse examples.

Design and operation of a medium speed 12-cylinder coal-fueled diesel engine. Phase 2: Improvements

Science.gov (United States)

Confer, G. L.; Hsu, B. D.; McDowell, R. E.; Gal, E.; Vankleunen, W.; Kaldor, S.; Mengel, M.

Under the sponsorship of the US Department of Energy, General Electric has been pioneering the development of a coal fired diesel engine to power a locomotive. The feasibility of using a coal water slurry (CWS) mixture as a fuel in a medium speed diesel engine has been demonstrated with the first successful locomotive systems test in 1991 on the GE Transportation Systems test track in Erie, PA. Phase 2 of the development process incorporates the results of the programs research in durable engine parts, improved combustion efficiency, and emissions reduction. A GE 7FDL12 engine has been built using diamond insert injector nozzles, tungsten carbide coated piston rings, and tungsten carbide coated liners to overcome power assembly wear. Electronic controlled fuel injection for both diesel pilot and main CWS injector were incorporated to control injection timing. An envelop filter and copper oxide sorbent system were used to cleanup engine emissions. The system is capable of removing over 99% of the particulates, 90% of the SO2, and 85% of NO(x).

Switching EKF technique for rotor and stator resistance estimation in speed sensorless control of IMs

International Nuclear Information System (INIS)

Barut, Murat; Bogosyan, Seta; Gokasan, Metin

2007-01-01

High performance speed sensorless control of induction motors (IMs) calls for estimation and control schemes that offer solutions to parameter uncertainties as well as to difficulties involved with accurate flux/velocity estimation at very low and zero speed. In this study, a new EKF based estimation algorithm is proposed for the solution of both problems and is applied in combination with speed sensorless direct vector control (DVC). The technique is based on the consecutive execution of two EKF algorithms, by switching from one algorithm to another at every n sampling periods. The number of sampling periods, n, is determined based on the desired system performance. The switching EKF approach, thus applied, provides an accurate estimation of an increased number of parameters than would be possible with a single EKF algorithm. The simultaneous and accurate estimation of rotor, R r ' and stator, R s resistances, both in the transient and steady state, is an important challenge in speed sensorless IM control and reported studies achieving satisfactory results are few, if any. With the proposed technique in this study, the sensorless estimation of R r ' and R s is achieved in transient and steady state and in both high and low speed operation while also estimating the unknown load torque, velocity, flux and current components. The performance demonstrated by the simulation results at zero speed, as well as at low and high speed operation is very promising when compared with individual EKF algorithms performing either R r ' or R s estimation or with the few other approaches taken in past studies, which require either signal injection and/or a change of algorithms based on the speed range. The results also motivate utilization of the technique for multiple parameter estimation in a variety of control methods

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

DEFF Research Database (Denmark)

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...

Wind Speed Preview Measurement and Estimation for Feedforward Control of Wind Turbines

Science.gov (United States)

Simley, Eric J.

Wind turbines typically rely on feedback controllers to maximize power capture in below-rated conditions and regulate rotor speed during above-rated operation. However, measurements of the approaching wind provided by Light Detection and Ranging (lidar) can be used as part of a preview-based, or feedforward, control system in order to improve rotor speed regulation and reduce structural loads. But the effectiveness of preview-based control depends on how accurately lidar can measure the wind that will interact with the turbine. In this thesis, lidar measurement error is determined using a statistical frequency-domain wind field model including wind evolution, or the change in turbulent wind speeds between the time they are measured and when they reach the turbine. Parameters of the National Renewable Energy Laboratory (NREL) 5-MW reference turbine model are used to determine measurement error for a hub-mounted circularly-scanning lidar scenario, based on commercially-available technology, designed to estimate rotor effective uniform and shear wind speed components. By combining the wind field model, lidar model, and turbine parameters, the optimal lidar scan radius and preview distance that yield the minimum mean square measurement error, as well as the resulting minimum achievable error, are found for a variety of wind conditions. With optimized scan scenarios, it is found that relatively low measurement error can be achieved, but the attainable measurement error largely depends on the wind conditions. In addition, the impact of the induction zone, the region upstream of the turbine where the approaching wind speeds are reduced, as well as turbine yaw error on measurement quality is analyzed. In order to minimize the mean square measurement error, an optimal measurement prefilter is employed, which depends on statistics of the correlation between the preview measurements and the wind that interacts with the turbine. However, because the wind speeds encountered by

High speed phase retrieval of in-line holograms by the assistance of corresponding off-axis holograms.

Science.gov (United States)

Orzó, László

2015-06-29

Retrieving correct phase information from an in-line hologram is difficult as the object wave field and the diffractions of the zero order and the conjugate object term overlap. The existing iterative numerical phase retrieval methods are slow, especially in the case of high Fresnel number systems. Conversely, the reconstruction of the object wave field from an off-axis hologram is simple, but due to the applied spatial frequency filtering the achievable resolution is confined. Here, a new, high-speed algorithm is introduced that efficiently incorporates the data of an auxiliary off-axis hologram in the phase retrieval of the corresponding in-line hologram. The efficiency of the introduced combined phase retrieval method is demonstrated by simulated and measured holograms.

Constant speed control of four-stroke micro internal combustion swing engine

Science.gov (United States)

Gao, Dedong; Lei, Yong; Zhu, Honghai; Ni, Jun

2015-09-01

The increasing demands on safety, emission and fuel consumption require more accurate control models of micro internal combustion swing engine (MICSE). The objective of this paper is to investigate the constant speed control models of four-stroke MICSE. The operation principle of the four-stroke MICSE is presented based on the description of MICSE prototype. A two-level Petri net based hybrid model is proposed to model the four-stroke MICSE engine cycle. The Petri net subsystem at the upper level controls and synchronizes the four Petri net subsystems at the lower level. The continuous sub-models, including breathing dynamics of intake manifold, thermodynamics of the chamber and dynamics of the torque generation, are investigated and integrated with the discrete model in MATLAB Simulink. Through the comparison of experimental data and simulated DC voltage output, it is demonstrated that the hybrid model is valid for the four-stroke MICSE system. A nonlinear model is obtained from the cycle average data via the regression method, and it is linearized around a given nominal equilibrium point for the controller design. The feedback controller of the spark timing and valve duration timing is designed with a sequential loop closing design approach. The simulation of the sequential loop closure control design applied to the hybrid model is implemented in MATLAB. The simulation results show that the system is able to reach its desired operating point within 0.2 s, and the designed controller shows good MICSE engine performance with a constant speed. This paper presents the constant speed control models of four-stroke MICSE and carries out the simulation tests, the models and the simulation results can be used for further study on the precision control of four-stroke MICSE.

Motor control for a brushless DC motor

Science.gov (United States)

Peterson, William J. (Inventor); Faulkner, Dennis T. (Inventor)

1985-01-01

This invention relates to a motor control system for a brushless DC motor having an inverter responsively coupled to the motor control system and in power transmitting relationship to the motor. The motor control system includes a motor rotor speed detecting unit that provides a pulsed waveform signal proportional to rotor speed. This pulsed waveform signal is delivered to the inverter to thereby cause an inverter fundamental current waveform output to the motor to be switched at a rate proportional to said rotor speed. In addition, the fundamental current waveform is also pulse width modulated at a rate proportional to the rotor speed. A fundamental current waveform phase advance circuit is controllingly coupled to the inverter. The phase advance circuit is coupled to receive the pulsed waveform signal from the motor rotor speed detecting unit and phase advance the pulsed waveform signal as a predetermined function of motor speed to thereby cause the fundamental current waveform to be advanced and thereby compensate for fundamental current waveform lag due to motor winding reactance which allows the motor to operate at higher speeds than the motor is rated while providing optimal torque and therefore increased efficiency.

Tuning of the PI Controller Parameters of a PMSG Wind Turbine to Improve Control Performance under Various Wind Speeds

OpenAIRE

Yun-Su Kim; Il-Yop Chung; Seung-Il Moon

2015-01-01

This paper presents a method to seek the PI controller parameters of a PMSG wind turbine to improve control performance. Since operating conditions vary with the wind speed, therefore the PI controller parameters should be determined as a function of the wind speed. Small-signal modeling of a PMSG WT is implemented to analyze the stability under various operating conditions and with eigenvalues obtained from the small-signal model of the PMSG WT, which are coordinated by adjusting the PI con...

Observer Based Traction/Braking Control Design for High Speed Trains Considering Adhesion Nonlinearity

OpenAIRE

Cai, Wenchuan; Liao, Wenhao; Li, Danyong; Song, Yongduan

2014-01-01

Train traction/braking control, one of the key enabling technologies for automatic train operation, literally takes its action through adhesion force. However, adhesion coefficient of high speed train (HST) is uncertain in general because it varies with wheel-rail surface condition and running speed; thus, it is extremely difficult to be measured, which makes traction/braking control design and implementation of HSTs greatly challenging. In this work, force observers are applied to estimate t...

Rotor Speed Estimation Method Used in Dynamic Control of the Induction Motor

Directory of Open Access Journals (Sweden)

CRĂCIUNAŞ Gabriela

2013-10-01

Full Text Available In this paper it is proposed an algorithm for rotor speed estimation calculated directly from the rotor flux. The flux required for speed computation is estimated using Gopinath reduced order robust adaptive observer. In order to determine the structure of the observer we started from the state equations of the induction motor using spatial vectors written in fixed coordinates towards stator and considering the rotor speed constant. Quality of speed and rotor fluxestimation was evaluated from the results obtained during different operation regimes. The proposed algorithm was then tested for its usability in the case of indirect field oriented control based on the rotor flux of the induction motor by the simulation inMATLAB/Simulink.

Swing Phase Control of Semi-Active Prosthetic Knee Using Neural Network Predictive Control With Particle Swarm Optimization.

Science.gov (United States)

Ekkachai, Kittipong; Nilkhamhang, Itthisek

2016-11-01

In recent years, intelligent prosthetic knees have been developed that enable amputees to walk as normally as possible when compared to healthy subjects. Although semi-active prosthetic knees utilizing magnetorheological (MR) dampers offer several advantages, they lack the ability to generate active force that is required during some states of a normal gait cycle. This prevents semi-active knees from achieving the same level of performance as active devices. In this work, a new control algorithm for a semi-active prosthetic knee during the swing phase is proposed to reduce this gap. The controller uses neural network predictive control and particle swarm optimization to calculate suitable command signals. Simulation results using a double pendulum model show that the generated knee trajectory of the proposed controller is more similar to the normal gait than previous open-loop controllers at various ambulation speeds. Moreover, the investigation shows that the algorithm can be calculated in real time by an embedded system, allowing for easy implementation on real prosthetic knees.

High speed TV-towing system for exploration manganese nodules

International Nuclear Information System (INIS)

Hartmann, P.

1977-12-01

For the oceanographic, special for the manganese nodules exploration in the deep sea a high speed-TV-towing system is to design on base of existing TV-towing systems to get better efficiency during the exploration phase. It is planned to increase to towing speed at the time of 2 knots up to 6-8 knots. The essential points of developments in this direction are 1) to decrease the hydrodynamical drag of the long towing cable with fairings. 2) To seperate to towing system into two units the passiv controlled towing cable end point 'SEP' with negativ buoyancy (weight) and the activ controlled TV-fish. With this separation it is possible to tow the TV-fish within a defined accuracy parallel to the sea floor without an influence to the overall system. 3) To adapt the TV- and photo stobe light unit for these towing conditions (high speed). 4) To design the control concept, the operating equipment, the energy and data transmission system, the towed body concept, the hydrodynamical calculation of towing phase and the other towed components. The results of this study is the definition of a two body towing system which is able towed by a research vessel to make continously TV-observation of the sea floor in depth down to 6,000 meters. (orig.) [de

Robust Adaptive Speed Control of Induction Motor Drives

DEFF Research Database (Denmark)

Bidstrup, N.

This thesis concerns speed control of current vector controlled induction motor drives (CVC drives). The CVC drive is an existing prototype drive developed by Danfoss A/S, Transmission Division. Practical tests have revealed that the open loop dynamical properties of the CVC drive are highly......, (LS) identification and generalized predictive control (GPC) has been implemented and tested on the CVC drive. Allthough GPC is a robust control method, it was not possible to maintain specified controller performance in the entire operating range. This was the main reason for investigating truly...... and measurement noise in general, were the major reasons for the drifting parameters. Two approaches was proposed to robustify MASTR2 against the output noise. The first approach consists of filtering the output. Output filtering had a significant effect in simulations, but the robustness against the output noise...

Fuzzy Adaptive Model Following Speed Control for Vector Controlled Permanent Magnet Synchronous Motor

Directory of Open Access Journals (Sweden)

Baghdad BELABES

2008-12-01

Full Text Available In this paper a hybrid controller combining a linear model following controller (LMFC and fuzzy logic control (FLC for speed vector controlled permanent magnet synchronous motor (PMSM is described on this study. The FLC is introduced at the adaptive mechanism level. First, an LMFC system is designed to allow the plant states to be controlled to follow the states produced by a reference model. In the nominal conditions, the model following is perfect and the adaptive mechanism based on the fuzzy logic is idle. Secondly, when parameter variations or external disturbances occur, an augmented signal will be generated by FLC mechanism to preserve the desired model following control performance. The effectiveness and robustness of the proposed controller is demonstrated by some simulation results.

Investigation of Inner Loop Flight Control Strategies for High-Speed Research

Science.gov (United States)

Newman, Brett; Kassem, Ayman

1999-01-01

This report describes the activities and findings conducted under contract NAS1-19858 with NASA Langley Research Center. Subject matter is the investigation of suitable flight control design methodologies and solutions for large, flexible high-speed vehicles. Specifically, methodologies are to address the inner control loops used for stabilization and augmentation of a highly coupled airframe system possibly involving rigid-body motion, structural vibrations, unsteady aerodynamics, and actuator dynamics. Techniques considered in this body of work are primarily conventional-based, and the vehicle of interest is the High-Speed Civil Transport (HSCT). Major findings include 1) current aeroelastic vehicle modeling procedures require further emphasis and refinement, 2) traditional and nontraditional inner loop flight control strategies employing a single feedback loop do not appear sufficient for highly flexible HSCT class vehicles, 3) inner loop flight control systems will, in all likelihood, require multiple interacting feedback loops, and 4) Ref. H HSCT configuration presents major challenges to designing acceptable closed-loop flight dynamics.

Vision-Based Steering Control, Speed Assistance and Localization for Inner-City Vehicles

Directory of Open Access Journals (Sweden)

Miguel Angel Olivares-Mendez

2016-03-01

Full Text Available Autonomous route following with road vehicles has gained popularity in the last few decades. In order to provide highly automated driver assistance systems, different types and combinations of sensors have been presented in the literature. However, most of these approaches apply quite sophisticated and expensive sensors, and hence, the development of a cost-efficient solution still remains a challenging problem. This work proposes the use of a single monocular camera sensor for an automatic steering control, speed assistance for the driver and localization of the vehicle on a road. Herein, we assume that the vehicle is mainly traveling along a predefined path, such as in public transport. A computer vision approach is presented to detect a line painted on the road, which defines the path to follow. Visual markers with a special design painted on the road provide information to localize the vehicle and to assist in its speed control. Furthermore, a vision-based control system, which keeps the vehicle on the predefined path under inner-city speed constraints, is also presented. Real driving tests with a commercial car on a closed circuit finally prove the applicability of the derived approach. In these tests, the car reached a maximum speed of 48 km/h and successfully traveled a distance of 7 km without the intervention of a human driver and any interruption.

Vision-Based Steering Control, Speed Assistance and Localization for Inner-City Vehicles.

Science.gov (United States)

Olivares-Mendez, Miguel Angel; Sanchez-Lopez, Jose Luis; Jimenez, Felipe; Campoy, Pascual; Sajadi-Alamdari, Seyed Amin; Voos, Holger

2016-03-11

Autonomous route following with road vehicles has gained popularity in the last few decades. In order to provide highly automated driver assistance systems, different types and combinations of sensors have been presented in the literature. However, most of these approaches apply quite sophisticated and expensive sensors, and hence, the development of a cost-efficient solution still remains a challenging problem. This work proposes the use of a single monocular camera sensor for an automatic steering control, speed assistance for the driver and localization of the vehicle on a road. Herein, we assume that the vehicle is mainly traveling along a predefined path, such as in public transport. A computer vision approach is presented to detect a line painted on the road, which defines the path to follow. Visual markers with a special design painted on the road provide information to localize the vehicle and to assist in its speed control. Furthermore, a vision-based control system, which keeps the vehicle on the predefined path under inner-city speed constraints, is also presented. Real driving tests with a commercial car on a closed circuit finally prove the applicability of the derived approach. In these tests, the car reached a maximum speed of 48 km/h and successfully traveled a distance of 7 km without the intervention of a human driver and any interruption.

Vision-Based Steering Control, Speed Assistance and Localization for Inner-City Vehicles

Science.gov (United States)

Olivares-Mendez, Miguel Angel; Sanchez-Lopez, Jose Luis; Jimenez, Felipe; Campoy, Pascual; Sajadi-Alamdari, Seyed Amin; Voos, Holger

2016-01-01

Autonomous route following with road vehicles has gained popularity in the last few decades. In order to provide highly automated driver assistance systems, different types and combinations of sensors have been presented in the literature. However, most of these approaches apply quite sophisticated and expensive sensors, and hence, the development of a cost-efficient solution still remains a challenging problem. This work proposes the use of a single monocular camera sensor for an automatic steering control, speed assistance for the driver and localization of the vehicle on a road. Herein, we assume that the vehicle is mainly traveling along a predefined path, such as in public transport. A computer vision approach is presented to detect a line painted on the road, which defines the path to follow. Visual markers with a special design painted on the road provide information to localize the vehicle and to assist in its speed control. Furthermore, a vision-based control system, which keeps the vehicle on the predefined path under inner-city speed constraints, is also presented. Real driving tests with a commercial car on a closed circuit finally prove the applicability of the derived approach. In these tests, the car reached a maximum speed of 48 km/h and successfully traveled a distance of 7 km without the intervention of a human driver and any interruption. PMID:26978365

Variable speed wind turbine control by discrete-time sliding mode approach.

Science.gov (United States)

Torchani, Borhen; Sellami, Anis; Garcia, Germain

2016-05-01

The aim of this paper is to propose a new design variable speed wind turbine control by discrete-time sliding mode approach. This methodology is designed for linear saturated system. The saturation constraint is reported on inputs vector. To this end, the back stepping design procedure is followed to construct a suitable sliding manifold that guarantees the attainment of a stabilization control objective. It is well known that the mechanisms are investigated in term of the most proposed assumptions to deal with the damping, shaft stiffness and inertia effect of the gear. The objectives are to synthesize robust controllers that maximize the energy extracted from wind, while reducing mechanical loads and rotor speed tracking combined with an electromagnetic torque. Simulation results of the proposed scheme are presented. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Second-order Sliding Mode Control of DFIG Based Variable Speed Wind Turbine for Maximum Power Point Tracking

Institute of Scientific and Technical Information of China (English)

Xiangjie Liu; Chengcheng Wang; Yaozhen Han

2017-01-01

This paper proposes a super-twisting second order sliding mode control scheme to maximize the wind energy capture of a doubly fed induction generator based variable speed wind turbine (VSWT) system, and minimize the reactive power simultaneously. Two second order sliding mode controllers are designed to achieve the control objectives, reduce mechanical stress and improve control accuracy. By regulating the generator rotor voltage, one controller makes the wind turbine rotor speed track the optimal speed, which can maximize power generation. The other maintains the rotor current at rated value to minimize the reactive power. A quadratic form Lyapunov function is adopted to determine the range of controller parameters and guarantee the finite time stability. Simulation results on a 1.5 MW doubly fed induction generator (DFIG)-based variable speed wind turbine demonstrate the validity of the proposed control strategy.

Speed control device for coolant recycling pump

International Nuclear Information System (INIS)

Kageyama, Takao.

1992-01-01

The present invention intends to increase a margin relative of the oscillations of neutron fluxes when the temperature of feedwater is lowered in a compulsory recycling type BWR reactor. That is, when the operation point represented by a reactor thermal power and a reactor core inlet flow rate is in a state approximate to an oscillation limit of the reactor power, the device of the present invention controls the recycling pump speed in the increasing direction depending on the lowering range of the feedwater temperature from a stationary state. With such a constitution, even if the reactor power is in the operation region near the oscillation limit in the BWR type reactor and a feedwater heating loss is caused, the speed of the coolant recycling pump is increased by 10% at the maximum depending on the extent of the reduction of the feedwater temperature, so that the oscillation of the reactor power can be prevented from lasting for a long period of time even if a reactivity external disturbance should occur in the reactor. (I.S.)

Phased array antenna control

Science.gov (United States)

Doland, G. D. (Inventor)

1978-01-01

Several new and useful improvements in steering and control of phased array antennas having a small number of elements, typically on the order of 5 to 17 elements are provided. Among the improvements are increasing the number of beam steering positions, reducing the possibility of phase transients in signals received or transmitted with the antennas, and increasing control and testing capacity with respect to the antennas.

Performance comparison of control schemes for variable-speed wind turbines

Science.gov (United States)

Bottasso, C. L.; Croce, A.; Savini, B.

2007-07-01

We analyze the performance of different control schemes when applied to the regulation problem of a variable-speed representative wind turbine. In particular, we formulate and compare a wind-scheduled PID, a LQR controller and a novel adaptive non-linear model predictive controller, equipped with observers of the tower states and wind. The simulations include gusts and turbulent winds of varying intensity in nominal as well as off-design operating conditions. The experiments highlight the possible advantages of model-based non-linear control strategies.

Performance comparison of control schemes for variable-speed wind turbines

International Nuclear Information System (INIS)

Bottasso, C L; Croce, A; Savini, B

2007-01-01

We analyze the performance of different control schemes when applied to the regulation problem of a variable-speed representative wind turbine. In particular, we formulate and compare a wind-scheduled PID, a LQR controller and a novel adaptive non-linear model predictive controller, equipped with observers of the tower states and wind. The simulations include gusts and turbulent winds of varying intensity in nominal as well as off-design operating conditions. The experiments highlight the possible advantages of model-based non-linear control strategies

Rural variable speed limits : phase II.

Science.gov (United States)

2012-05-01

The Wyoming Department of Transportation (WYDOT) installed its first variable speed limit (VSL) corridor along : Interstate 80 in the Elk Mountain Corridor in the Spring of 2009 in an effort to improve safety and reduce road closures, : particularly ...

Sliding mode direct power control of RSC for DFIGs driven by variable speed wind turbines

Directory of Open Access Journals (Sweden)

E.G. Shehata

2015-12-01

Full Text Available In spite of its several advantages, a classic direct power control (DPC of doubly fed induction generators (DFIGs driven by variable speed wind turbines has some drawbacks. In this paper, a simple and robust total sliding mode controller (TSMC is designed to improve the classical DPC performance without complicating the overall scheme. The TSMC is designed to regulate the DFIG stator active and reactive powers. Two integral switching functions are selected for describing the switching surfaces of the active and reactive powers. Reaching phase stability problem of the classical sliding mode controller is avoided in the proposed TSMC. Neither current control loops nor accurate values of machine parameters are required in the proposed scheme. In addition, axes transformation of the stator voltage and current are eliminated. The grid side converter is controlled based on DPC principle to regulate both DC-link voltage and total reactive power. The feasibility of the proposed DPC scheme is validated through simulation studies on a 1.5 MW wind power generation system. The performance of the proposed and conventional DPC schemes is compared under different operating conditions.

Energy efficiency in speed control system for induction motors; Eficiencia energetica em sistema de controle de velocidade em motores de inducao

Energy Technology Data Exchange (ETDEWEB)

Silva, Arlete Vieira da; Ribeiro, Elisangela do Nascimento; Tenorio, Iana Cavalcanti; Horta, Mario Marcos Brito [Centro Universitario de Belo Horizonte (UnBH), MG (Brazil)], e-mails: arlete.silva@prof.unibh.br, nr.elisangela@gmail.com, ianactenorio@gmail.com, mario_bhorta@yahoo.com.br

2011-07-01

This work has as objective the study of energy efficiency of induction motors fed by frequency inverters, since this is a practical resource that has progressively allowed the replacement of mechanical speed reducers. In this work the speed control of induction motors of the squirrel cage has steeped through the frequency inverters using scalar control. Induction motors are frequently used in industrial applications due to its simple construction, its low maintenance and reduced in size. It was possible through tests made at UNI-BH Electrical Engineering laboratory to obtain satisfactory results regarding the performance of the inverter CFW08 (WEG), speed control of induction motor. (author)

Distributed flow sensing for closed-loop speed control of a flexible fish robot.

Science.gov (United States)

Zhang, Feitian; Lagor, Francis D; Yeo, Derrick; Washington, Patrick; Paley, Derek A

2015-10-23

Flexibility plays an important role in fish behavior by enabling high maneuverability for predator avoidance and swimming in turbulent flow. This paper presents a novel flexible fish robot equipped with distributed pressure sensors for flow sensing. The body of the robot is molded from soft, hyperelastic material, which provides flexibility. Its Joukowski-foil shape is conducive to modeling the fluid analytically. A quasi-steady potential-flow model is adopted for real-time flow estimation, whereas a discrete-time vortex-shedding flow model is used for higher-fidelity simulation. The dynamics for the flexible fish robot yield a reduced model for one-dimensional swimming. A recursive Bayesian filter assimilates pressure measurements to estimate flow speed, angle of attack, and foil camber. The closed-loop speed-control strategy combines an inverse-mapping feedforward controller based on an average model derived for periodic actuation of angle-of-attack and a proportional-integral feedback controller utilizing the estimated flow information. Simulation and experimental results are presented to show the effectiveness of the estimation and control strategy. The paper provides a systematic approach to distributed flow sensing for closed-loop speed control of a flexible fish robot by regulating the flapping amplitude.

Effect of Lunar Phases, Tides, and Wind Speed on the Abundance of Diptera Calliphoridae in a Mangrove Swamp.

Science.gov (United States)

Batista-da-Silva, J A

2014-02-01

Abiotic factors, such as lunar phases and tides, have a significant effect on insect development. Reproduction and immature development are usually interlinked to these abiotic factors. The tide is at its highest levels at full moon or new moon, hindering the feeding of the immature or causing their drowning. The oviposition by adult females is also compromised on these days because much of the available food is submerged. Another important abiotic factor is the wind, which displaces odoriferous particles in the air. Wind speed and direction are important elements to indicate potential sources of food for insects. I report on the effects of lunar phases, tides, and wind speed on the Calliphoridae fauna in mangrove swamps. The different species collected were identified, and the predominant species in the area were quantified. A total of 1,710 flies were collected over a 1-year period. Six Calliphoridae flies, Chloroprocta idioidea (Robineau-Desvoidy), Chrysomya megacephala (Fabricius), Chrysomya albiceps (Wiedemann), Chrysomya putoria (Wiedemann), Cochliomyia macellaria (Fabricius), and Lucilia eximia (Wiedemann) were collected. Data indicated that lunar phases have a significant effect on the abundance of C. albiceps (r = 0.39, p tides also affected the abundance of C. putoria (r = 0.40, p < 0.00), C. macellaria (r = 0.41, p < 0.00), and C. idioidea (r = 0.31, p < 0.04). The wind speed, however, did not affect these species.

Deformation-phase transformation coupling mechanism of white layer formation in high speed machining of FGH95 Ni-based superalloy

Energy Technology Data Exchange (ETDEWEB)

Du, Jin [School of Mechanical and Automotive Engineering, Qilu University of Technology, Jinan, Shandong 250353 (China); Liu, Zhanqiang, E-mail: melius@sdu.edu.cn [School of Mechanical Engineering, Shandong University, Jinan, Shandong 250061 (China); Key Laboratory of High Efficiency and Clean Mechanical Manufacture, Shandong University, Ministry of Education, Shandong (China); Lv, Shaoyu [School of Mechanical Engineering, Shandong University, Jinan, Shandong 250061 (China)

2014-02-15

Ni-based superalloy represents a significant metal portion of the aircraft critical structural and engine components. When these critical structural components in aerospace industry are manufactured with the objective to reach high reliability levels and excellent service performance, surface integrity is one of the most relevant parameter used for evaluating the quality of finish machined surfaces. In the study of surface integrity, the formation white layer is a very important research topic. The formation of white layer on the Ni-based superalloy machined surface will reduce the machined parts service performance and fatigue life. This paper was conducted to determine the effects of cutting speed on white layer formation in high speed machining of FGH95 Ni-based superalloy. Optical microscope, scanning electron microscope and X-ray diffraction were employed to analyze the elements and microstructures of white layer and bulk materials. The statistical analysis for grain numbers was executed to study the influence of cutting speed on the grain refinement in the machined surface. The investigation results showed that white layer exhibits significantly different microstructures with the bulk materials. It shows densification, no obvious structural features characteristic. The microstructure and phase of Ni-based solid solution changed during cutting process. The increase of cutting speed causes the increase of white layer thickness when the cutting speed is less than 2000 m/min. However, white layer thickness reduces with the cutting speed further increase. The higher the cutting speed, the more serious grains refinement in machined surface. 2-D FEM for machining FGH95 were carried out to simulate the cutting process and obtained the cutting temperature field, cutting strain field and strain rate field. The impact mechanisms of cutting temperature, cutting strain and strain rates on white layer formation were analyzed. At last, deformation-phase transformation

Online Dynamic Balance Technology for High Speed Spindle Based on Gain Parameter Adaption and Scheduling Control

Directory of Open Access Journals (Sweden)

Shihai Zhang

2018-06-01

Full Text Available Unbalance vibration is one of the main vibration forms of a high speed machine tool spindle. The overlarge unbalance vibration will have some adverse effects on the working life of the spindle system and the surface quality of the work-piece. In order to reduce the unbalance of a high speed spindle system, a pneumatic online dynamic balance device and its control system are presented in the paper. To improve the balance accuracy and adaptation of the balance system, the gain parameter adaption and scheduling control method are proposed first, and then the different balance effects of the influence coefficient method and the gain scheduling control method are compared through many dynamic balance experiments of the high speed spindle. The experimental results indicate that the gain parameters can be changed timely according to the transformation of the speed and kinetic parameters of the spindle system. The balance accuracy can be improved for a high speed spindle with time-varying characteristics, based on the adaptive gain scheduling control method.

High speed real-time wavefront processing system for a solid-state laser system

Science.gov (United States)

Liu, Yuan; Yang, Ping; Chen, Shanqiu; Ma, Lifang; Xu, Bing

2008-03-01

A high speed real-time wavefront processing system for a solid-state laser beam cleanup system has been built. This system consists of a core2 Industrial PC (IPC) using Linux and real-time Linux (RT-Linux) operation system (OS), a PCI image grabber, a D/A card. More often than not, the phase aberrations of the output beam from solid-state lasers vary fast with intracavity thermal effects and environmental influence. To compensate the phase aberrations of solid-state lasers successfully, a high speed real-time wavefront processing system is presented. Compared to former systems, this system can improve the speed efficiently. In the new system, the acquisition of image data, the output of control voltage data and the implementation of reconstructor control algorithm are treated as real-time tasks in kernel-space, the display of wavefront information and man-machine conversation are treated as non real-time tasks in user-space. The parallel processing of real-time tasks in Symmetric Multi Processors (SMP) mode is the main strategy of improving the speed. In this paper, the performance and efficiency of this wavefront processing system are analyzed. The opened-loop experimental results show that the sampling frequency of this system is up to 3300Hz, and this system can well deal with phase aberrations from solid-state lasers.

Quantitative measurement of vocal fold vibration in male radio performers and healthy controls using high-speed videoendoscopy.

Directory of Open Access Journals (Sweden)

Samantha Warhurst

Full Text Available Acoustic and perceptual studies show a number of differences between the voices of radio performers and controls. Despite this, the vocal fold kinematics underlying these differences are largely unknown. Using high-speed videoendoscopy, this study sought to determine whether the vocal vibration features of radio performers differed from those of non-performing controls.Using high-speed videoendoscopy, recordings of a mid-phonatory/i/ in 16 male radio performers (aged 25-52 years and 16 age-matched controls (aged 25-52 years were collected. Videos were extracted and analysed semi-automatically using High-Speed Video Program, obtaining measures of fundamental frequency (f0, open quotient and speed quotient. Post-hoc analyses of sound pressure level (SPL were also performed (n = 19. Pearson's correlations were calculated between SPL and both speed and open quotients.Male radio performers had a significantly higher speed quotient than their matched controls (t = 3.308, p = 0.005. No significant differences were found for f0 or open quotient. No significant correlation was found between either open or speed quotient with SPL.A higher speed quotient in male radio performers suggests that their vocal fold vibration was characterised by a higher ratio of glottal opening to closing times than controls. This result may explain findings of better voice quality, higher equivalent sound level and greater spectral tilt seen in previous research. Open quotient was not significantly different between groups, indicating that the durations of complete vocal fold closure were not different between the radio performers and controls. Further validation of these results is required to determine the aetiology of the higher speed quotient result and its implications for voice training and clinical management in performers.

L1 Adaptive Manoeuvring Control of Unmanned High-speed Water Craft

DEFF Research Database (Denmark)

Svendsen, Casper H.; Holck, Niels Ole; Galeazzi, Roberto

2012-01-01

This work addresses the issue of designing an adaptive robust control system to govern the steering of a high speed unmanned personal watercraft (PWC) maintaining equal performance across the craft’s envelope of operation. The maneuvering dynamics of a high speed PWC is presented and a strong var......-of-freedom surge-sway-yaw-roll model. An L1 adaptive autopilot is then designed, which allows to achieve fast adaption to system parameters’ changes and robustness of the closed loop system....

Speed tracking control of pneumatic motor servo systems using observation-based adaptive dynamic sliding-mode control

Science.gov (United States)

Chen, Syuan-Yi; Gong, Sheng-Sian

2017-09-01

This study aims to develop an adaptive high-precision control system for controlling the speed of a vane-type air motor (VAM) pneumatic servo system. In practice, the rotor speed of a VAM depends on the input mass air flow, which can be controlled by the effective orifice area (EOA) of an electronic throttle valve (ETV). As the control variable of a second-order pneumatic system is the integral of the EOA, an observation-based adaptive dynamic sliding-mode control (ADSMC) system is proposed to derive the differential of the control variable, namely, the EOA control signal. In the ADSMC system, a proportional-integral-derivative fuzzy neural network (PIDFNN) observer is used to achieve an ideal dynamic sliding-mode control (DSMC), and a supervisor compensator is designed to eliminate the approximation error. As a result, the ADSMC incorporates the robustness of a DSMC and the online learning ability of a PIDFNN. To ensure the convergence of the tracking error, a Lyapunov-based analytical method is employed to obtain the adaptive algorithms required to tune the control parameters of the online ADSMC system. Finally, our experimental results demonstrate the precision and robustness of the ADSMC system for highly nonlinear and time-varying VAM pneumatic servo systems.

Energy efficient power electronic controller for a capacitor-run single-phase induction motor

International Nuclear Information System (INIS)

Saravana Ilango, G.; Samidurai, K.; Roykumar, M.; Thanushkodi, K.

2009-01-01

At present the speed control of a capacitor-run single-phase induction motor is being achieved by using triac based voltage regulators. This paper proposes a new scheme; an electronic transformer acts as a voltage regulator. Performance comparison is made between these two schemes in this paper. It is found that the proposed scheme has superior operating and performance characteristics. Experimental results show that apart from improvement in performance with respect to power factor and total harmonic distortion an appreciable amount of energy saving is also obtained in the electronic transformer based scheme.

Differential effects of absent visual feedback control on gait variability during different locomotion speeds.

Science.gov (United States)

Wuehr, M; Schniepp, R; Pradhan, C; Ilmberger, J; Strupp, M; Brandt, T; Jahn, K

2013-01-01

Healthy persons exhibit relatively small temporal and spatial gait variability when walking unimpeded. In contrast, patients with a sensory deficit (e.g., polyneuropathy) show an increased gait variability that depends on speed and is associated with an increased fall risk. The purpose of this study was to investigate the role of vision in gait stabilization by determining the effects of withdrawing visual information (eyes closed) on gait variability at different locomotion speeds. Ten healthy subjects (32.2 ± 7.9 years, 5 women) walked on a treadmill for 5-min periods at their preferred walking speed and at 20, 40, 70, and 80 % of maximal walking speed during the conditions of walking with eyes open (EO) and with eyes closed (EC). The coefficient of variation (CV) and fractal dimension (α) of the fluctuations in stride time, stride length, and base width were computed and analyzed. Withdrawing visual information increased the base width CV for all walking velocities (p < 0.001). The effects of absent visual information on CV and α of stride time and stride length were most pronounced during slow locomotion (p < 0.001) and declined during fast walking speeds. The results indicate that visual feedback control is used to stabilize the medio-lateral (i.e., base width) gait parameters at all speed sections. In contrast, sensory feedback control in the fore-aft direction (i.e., stride time and stride length) depends on speed. Sensory feedback contributes most to fore-aft gait stabilization during slow locomotion, whereas passive biomechanical mechanisms and an automated central pattern generation appear to control fast locomotion.

The development of an open architecture control system for CBN high speed grinding

OpenAIRE

Silva, E. Jannone da; Biffi, M.; Oliveira, J. F. G. de

2004-01-01

The aim of this project is the development of an open architecture controlling (OAC) system to be applied in the high speed grinding process using CBN tools. Besides other features, the system will allow a new monitoring and controlling strategy, by the adoption of open architecture CNC combined with multi-sensors, a PC and third-party software. The OAC system will be implemented in a high speed CBN grinding machine, which is being developed in a partnership between the University of São Paul...

A wide range and high speed automatic gain control

International Nuclear Information System (INIS)

Tacconi, E.; Christiansen, C.

1993-05-01

Automatic gain control (AGC) techniques have been largely used since the beginning of electronics, but in most of the applications the dynamic response is slow compared with the carrier frequency. The problem of developing an automatic gain control with high dynamic response and wide control range simultaneously is analyzed in this work. An ideal gain control law, with the property that the total loop gain remains constant independent of the carrier amplitude, is obtained. The resulting AGC behavior is compared by computer simulations with a linear multiplier AGC. The ideal gain control law can be approximated using a transconductance amplifier. A practical circuit that has been used at CERN in the radio frequency loops of the Booster Synchrotron is presented. The circuit has high speed and 80-dB gain control range

Modulation of walking speed by changing optic flow in persons with stroke

Directory of Open Access Journals (Sweden)

Lamontagne Anouk

2007-06-01

Full Text Available Abstract Background Walking speed, which is often reduced after stroke, can be influenced by the perception of optic flow (OF speed. The present study aims to: 1 compare the modulation of walking speed in response to OF speed changes between persons with stroke and healthy controls and 2 investigate whether virtual environments (VE manipulating OF speed can be used to promote volitional changes in walking speed post stroke. Methods Twelve persons with stroke and 12 healthy individuals walked on a self-paced treadmill while viewing a virtual corridor in a helmet-mounted display. Two experiments were carried out on the same day. In experiment 1, the speed of an expanding OF was varied sinusoidally at 0.017 Hz (sine duration = 60 s, from 0 to 2 times the subject's comfortable walking speed, for a total duration of 5 minutes. In experiment 2, subjects were exposed to expanding OFs at discrete speeds that ranged from 0.25 to 2 times their comfortable speed. Each test trial was paired with a control trial performed at comfortable speed with matching OF. For each of the test trials, subjects were instructed to walk the distance within the same time as during the immediately preceding control trial. VEs were controlled by the CAREN-2 system (Motek. Instantaneous changes in gait speed (experiment 1 and the ratio of speed changes in the test trial over the control trial (experiment 2 were contrasted between the two groups of subjects. Results When OF speed was changing continuously (experiment 1, an out-of-phase modulation was observed in the gait speed of healthy subjects, such that slower OFs induced faster walking speeds, and vice versa. Persons with stroke displayed weaker (p 0.05, T-test. Conclusion Stroke affects the modulation of gait speed in response to changes in the perception of movement through different OF speeds. Nevertheless, the preservation of even a modest modulation enabled the persons with stroke to increase walking speed when

Analysis of Wind Speed Forecasting Error Effects on Automatic Generation Control Performance

Directory of Open Access Journals (Sweden)

H. Rajabi Mashhadi

2014-09-01

Full Text Available The main goal of this paper is to study statistical indices and evaluate AGC indices in power system which has large penetration of the WTGs. Increasing penetration of wind turbine generations, needs to study more about impacts of it on power system frequency control. Frequency control is changed with unbalancing real-time system generation and load . Also wind turbine generations have more fluctuations and make system more unbalance. Then AGC loop helps to adjust system frequency and the scheduled tie-line powers. The quality of AGC loop is measured by some indices. A good index is a proper measure shows the AGC performance just as the power system operates. One of well-known measures in literature which was introduced by NERC is Control Performance Standards(CPS. Previously it is claimed that a key factor in CPS index is related to standard deviation of generation error, installed power and frequency response. This paper focuses on impact of a several hours-ahead wind speed forecast error on this factor. Furthermore evaluation of conventional control performances in the power systems with large-scale wind turbine penetration is studied. Effects of wind speed standard deviation and also degree of wind farm penetration are analyzed and importance of mentioned factor are criticized. In addition, influence of mean wind speed forecast error on this factor is investigated. The study system is a two area system which there is significant wind farm in one of those. The results show that mean wind speed forecast error has considerable effect on AGC performance while the mentioned key factor is insensitive to this mean error.

Observer Based Traction/Braking Control Design for High Speed Trains Considering Adhesion Nonlinearity

Directory of Open Access Journals (Sweden)

Wenchuan Cai

2014-01-01

Full Text Available Train traction/braking control, one of the key enabling technologies for automatic train operation, literally takes its action through adhesion force. However, adhesion coefficient of high speed train (HST is uncertain in general because it varies with wheel-rail surface condition and running speed; thus, it is extremely difficult to be measured, which makes traction/braking control design and implementation of HSTs greatly challenging. In this work, force observers are applied to estimate the adhesion force or/and the resistance, based on which simple traction/braking control schemes are established under the consideration of actual wheel-rail adhesion condition. It is shown that the proposed controllers have simple structure and can be easily implemented from real applications. Numerical simulation also validates the effectiveness of the proposed control scheme.

A novel technology for control of variable speed pumped storage power plant

Institute of Scientific and Technical Information of China (English)

Seyed Mohammad Hassan Hosseini; Mohammad Reza Semsar

2016-01-01

Variable speed pumped storage machines are used extensively in wind power plant and pumped storage power plant. This paper presents direct torque and flux control (DTFC) of a variable speed pumped storage power plant (VSPSP). By this method both torque and flux have been applied to control the VSPSP. The comparison between VSPSP’s control strategies is studied. At the first, a wind turbine with the capacity 2.2 kW and DTFC control strategies simulated then a 250 MW VSPSP is simulated with all of its parts (including electrical, mechanical, hydraulic and its control system) by MATLAB software. In all of simulations, both converters including two-level voltage source converter (2LVSC) and three-level voltage source converter (3LVSC) are applied. The results of applying 2LVSC and 3LVSC are the rapid dynamic responses with better efficiency, reducing the total harmonic distortion (THD) and ripple of rotor torque and flux.

Direct Torque Control with Full Order Stator Flux Observer for Dual-Three Phase Induction Motor Drives

Science.gov (United States)

Farina, Francesco; Bojoi, Radu; Tenconi, Alberto; Profumo, Francesco

A Direct Torque Control (DTC) strategy for dual-three phase induction motor drives is discussed in this paper. The induction machine has two sets of stator three-phase windings spatially shifted by 30 electrical degrees with isolated neutral points. The proposed control strategy is based on Proportional Integral (PI) regulators implemented in the stator flux synchronous reference frame. To improve the flux estimation, an Adaptive Stator Flux Observer (ASFO) has been used. Doing so, besides a better flux estimation in contrast to open-loop flux estimators, it is possible to use the observed currents to compensate the inverter non-linear behavior (such as dead-time effects), improving the drive performance at low speed. This is particularly important for low voltage/high current applications, as the drive considered in this paper. The advantages of the discussed control strategy are: constant inverter switching frequency, good transient and steady-state performance and less distorted machine currents in contrast to DTC schemes with variable switching frequency. Experimental results are presented for a 10kW dual three-phase induction motor drive prototype.

High Speed Magnetostrictive MEMS Actuated Mirror Deflectors, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — The main goal of this proposal is to develop high speed magnetostrictive and MEMS actuators for rapidly deflecting or deforming mirrors. High speed, light-weight,...

Simulation of three-phase induction motor drives using indirect field oriented control in PSIM environment

Science.gov (United States)

Aziri, Hasif; Patakor, Fizatul Aini; Sulaiman, Marizan; Salleh, Zulhisyam

2017-09-01

This paper presents the simulation of three-phase induction motor drives using Indirect Field Oriented Control (IFOC) in PSIM environment. The asynchronous machine is well known about natural limitations fact of highly nonlinearity and complexity of motor model. In order to resolve these problems, the IFOC is applied to control the instantaneous electrical quantities such as torque and flux component. As FOC is controlling the stator current that represented by a vector, the torque component is aligned with d coordinate while the flux component is aligned with q coordinate. There are five levels of the incremental system are gradually built up to verify and testing the software module in the system. Indeed, all of system build levels are verified and successfully tested in PSIM environment. Moreover, the corresponding system of five build levels are simulated in PSIM environment which is user-friendly for simulation studies in order to explore the performance of speed responses based on IFOC algorithm for three-phase induction motor drives.

Multi-objective PID Optimization for Speed Control of an Isolated Steam Turbine using Gentic Algorithm

OpenAIRE

Sanjay Kr. Singh; D. Boolchandani; S.G. Modani; Nitish Katal

2014-01-01

This study focuses on multi-objective optimization of the PID controllers for optimal speed control for an isolated steam turbine. In complex operations, optimal tuning plays an imperative role in maintaining the product quality and process safety. This study focuses on the comparison of the optimal PID tuning using Multi-objective Genetic Algorithm (NSGA-II) against normal genetic algorithm and Ziegler Nichols methods for the speed control of an isolated steam turbine. Isolated steam turbine...

Speed Synchronization Control of Integrated Motor–Transmission Powertrain over CAN through Active Period-Scheduling Approach

Directory of Open Access Journals (Sweden)

Wanke Cao

2017-11-01

Full Text Available This paper deals with the speed synchronization control of integrated motor–transmission (IMT powertrain systems in pure electric vehicles (EVs over a controller area network (CAN subject to both network-induced delays and network congestion. A CAN has advantages over point-to-point communication; however, it imposes network-induced delays and network congestion into the control system, which can deteriorate the shifting quality and make system integration difficult. This paper presents a co-design scheme combining active period scheduling and discrete-time slip mode control (SMC to deal with both network-induced delays and network congestion of the CAN, which improves the speed synchronization control for high shifting quality and prevents network congestion for the system’s integration. The results of simulations and hardware-in-loop experiments show the effectiveness of the proposed scheme, which can ensure satisfactory speed synchronization performance while significantly reducing the network’s utilization.

LQG Controller Design for Pitch Regulated Variable Speed Wind Turbine

DEFF Research Database (Denmark)

Imran, Raja Muhammed; Hussain, Dil Muhammad Akbar; Chen, Zhe

2014-01-01

Variable speed wind turbine is a complex and nonlinear system, a sophisticated control is required to meet the challenges posed by these systems. This paper is presenting a pitch regulation strategy based on LQG (Linear Quadratic Gaussian) to regulate turbine at its rated power and to reject...

Intelligent Multiobjective Slip and Speed Ratio Control of a Novel Dual-Belt Continuously Variable Transmission for Automobiles

Directory of Open Access Journals (Sweden)

Zhengchao Xie

2014-01-01

Full Text Available Van Doorne’s continuously variable transmission (CVT is the most popular CVT design for automotive transmission, but it is only applicable to low-power passenger cars because of its low torque capacity. To overcome this limitation of traditional single-belt CVT, a novel dual-belt Van Doorne’s CVT (DBVCVT system, which is applicable to heavy-duty vehicles, has been previously proposed by the authors. This paper, based on the published analytical model and test rig of DBVCVT, further proposes an intelligent multiobjective fuzzy controller for slip and speed ratio control of DBVCVT. The controller aims to safely control the clamping forces of both the primary and the secondary pulleys in order to improve the transmission efficiency, achieve the accurate speed ratio, and avoid the belt slip under different engine loads and vehicle speeds. The slip, speed ratio, and transmission efficiency dynamics of DBVCVT are firstly analyzed and modeled in this paper. With the aid of a flexible objective function, the analytical model, and fuzzy logic, a Pareto rule base for fuzzy controller is developed for multiobjective DBVCVT control. Experimental results show that the proposed controller for slip and speed ratio regulation of DBVCVT is effective and performs well under different user-defined weights.

Longer-term effects of ADAS use on speed and headway control in drivers diagnosed with Parkinson's disease

NARCIS (Netherlands)

Dotzauer, Mandy; Caljouw, Simone R.; De Waard, Dick; Brouwer, Wiebo H.

2015-01-01

Objective: An advanced driver assistance system (ADAS) provided information about speed limits, speed, speeding, and following distance. Information was presented to the participants by means of a head-up display. Methods: Effects of the information on speed and headway control were studied in a

Speed control of induction motor using fuzzy recursive least squares technique

Directory of Open Access Journals (Sweden)

Santiago Sánchez

2008-12-01

Full Text Available A simple adaptive controller design is presented in this paper, the control system uses the adaptive fuzzy logic, sliding modes and is trained with the recursive least squares technique. The problem of parameter variation is solved with the adaptive controller; the use of an internal PI regulator produces that the speed control of the induction motor be achieved by the stator currents instead the input voltage. The rotor-flux oriented coordinated system model is used to develop and test the control system.

Applications of variable speed control for contending with recurrent highway congestion.

Science.gov (United States)

2014-07-01

This research project developed vital operational guidelines for design of a variable speed limit (VSL) system and its integrated operations with ramp metering control in contending with recurrent highway congestion. The developed guidelines can serv...

Chattering-free sliding mode observer for speed sensorless control of PMSM

Directory of Open Access Journals (Sweden)

Mahmoud M. Gaballah

2017-07-01

Full Text Available This article presents a new speed observer based on fuzzy logic for speed sensorless control applications of permanent magnet synchronous motor “PMSM”. The switch function in traditional Sliding Mode Observer “SMO” is replaced by a rule based fuzzy logic system. The proposed observer not only improves the system dynamic performance during disturbances or parameter variations, but also has a high accuracy tracking performance with sufficient chattering reduction. The validity of the new observer corroborated through experimental results using TMS320F28069M Digital Signal Processor “DSP”.

Study on Application of T-S Fuzzy Observer in Speed Switching Control of AUVs Driven by States

Directory of Open Access Journals (Sweden)

Xun Zhang

2014-01-01

Full Text Available Considering the inherent strongly nonlinear and coupling performance of autonomous underwater vehicles (AUVs, the speed switching control method for AUV driven by states is presented. By using T-S fuzzy observer to estimate the states of AUV, the speed control strategies in lever plane, vertical plane, and speed kept are established, respectively. Then the adaptive switching law is introduced to switch the speed control strategies designed in real time. In the simulation, acoustic Doppler current profile/side scan sonar (ADCP/SSS observation case is employed to demonstrate the effectiveness of the proposed method. The results show that the efficiency of AUV was improved, the trajectory tracking error was reduced, and the steady-state ability was enhanced.

Can the traffic locus of control (T-LOC) scale be successfully used to predict Swedish drivers' speeding behaviour?

Science.gov (United States)

Warner, Henriette Wallén; Ozkan, Türker; Lajunen, Timo

2010-07-01

The first aim of the present study was to examine the factor structure of the traffic locus of control (T-LOC) scale in a Swedish sample of drivers. The second aim was to examine if this scale can be used to predict drivers' speeding behaviour. A sample of Swedish car owners (N=223) completed a questionnaire including questions based on the traffic locus of control (T-LOC) scale as well as questions about their speeding behaviour. The results showed a five factor solution including own skills, own behaviour, other drivers, vehicle/environment and fate. Own behaviour and vehicle/environment could be used to predict drivers' speeding behaviour on roads with a 90 km/h speed limit while none of the variables included in the traffic locus of control (T-LOC) scale could be used to predict drivers' speeding behaviour on roads with a 50 km/h speed limit. On 90 km/h roads own behaviour was positively related to drivers' speeding behaviour while vehicle/environment was negatively related to their speeding behaviour. Copyright 2010 Elsevier Ltd. All rights reserved.

Sensorless Stator Field-Oriented Controlled IM Drive at Low Speed with Rr Estimator

Directory of Open Access Journals (Sweden)

Wen-Cheng Pu

2014-01-01

Full Text Available This paper pertains to a technique of a sensorless indirect stator field-oriented induction motor control, which prevents the accumulative errors incurred by the integrator and the problem relating to the stability of the control system caused by the stator resistance susceptible to temperature variations while conducting the flux estimation directly and computing the synchronous rotary speed. The research adds an adaptive flux observer to estimate the speed of the rotor and uses the fixed trace algorithm (FTA to execute an online estimation of the slip difference, thereby improving the system of stability under the low rotary speed at regenerating mode and the influence of the rotor resistance on the slip angle. Finally, the paper conducts simulations by Simulink of MATLAB and practices to verify the correctness of the result the paper presents.

Design of permanent magnet synchronous motor speed loop controller based on sliding mode control algorithm

Science.gov (United States)

Qiang, Jiang; Meng-wei, Liao; Ming-jie, Luo

2018-03-01

Abstract.The control performance of Permanent Magnet Synchronous Motor will be affected by the fluctuation or changes of mechanical parameters when PMSM is applied as driving motor in actual electric vehicle,and external disturbance would influence control robustness.To improve control dynamic quality and robustness of PMSM speed control system, a new second order integral sliding mode control algorithm is introduced into PMSM vector control.The simulation results show that, compared with the traditional PID control,the modified control scheme optimized has better control precision and dynamic response ability and perform better with a stronger robustness facing external disturbance,it can effectively solve the traditional sliding mode variable structure control chattering problems as well.

Scandium doped Ge2Sb2Te5 for high-speed and low-power-consumption phase change memory

Science.gov (United States)

Wang, Yong; Zheng, Yonghui; Liu, Guangyu; Li, Tao; Guo, Tianqi; Cheng, Yan; Lv, Shilong; Song, Sannian; Ren, Kun; Song, Zhitang

2018-03-01

To bridge the gap of access time between memories and storage systems, the concept of storage class memory has been put forward based on emerging nonvolatile memory technologies. For all the nonvolatile memory candidates, the unpleasant tradeoff between operation speed and retention seems to be inevitable. To promote both the write speed and the retention of phase change memory (PCM), Sc doped Ge2Sb2Te5 (SGST) has been proposed as the storage medium. Octahedral Sc-Te motifs, acting as crystallization precursors to shorten the nucleation incubation period, are the possible reason for the high write speed of 6 ns in PCM cells, five-times faster than that of Ge2Sb2Te5 (GST) cells. Meanwhile, an enhanced 10-year data retention of 119 °C has been achieved. Benefiting from both the increased crystalline resistance and the inhibited formation of the hexagonal phase, the SGST cell has a 77% reduction in power consumption compared to the GST cell. Adhesion of the SGST/SiO2 interface has been strengthened, attributed to the reduced stress by forming smaller grains during crystallization, guaranteeing the reliability of the device. These improvements have made the SGST material a promising candidate for PCM application.

Optimal multivariable control of a wind turbine with variable speed

NARCIS (Netherlands)

Steinbuch, M.

1987-01-01

The control system design for a 310 kW horizontal axis wind energy conversion system with a synchronous generator and DC link is investigated. Because the wind turbine system has multiple inputs (pitch angle, field vollage alld delay angle), and multiple outputs, (speed and power), and because the

Is there really an eccentric action of the hamstrings during the swing phase of high-speed running? part I: A critical review of the literature.

Science.gov (United States)

Van Hooren, Bas; Bosch, Frans

2017-12-01

It is widely assumed that there is an eccentric hamstring muscle fibre action during the swing phase of high-speed running. However, animal and modelling studies in humans show that the increasing distance between musculotendinous attachment points during forward swing is primarily due to passive lengthening associated with the take-up of muscle slack. Later in the swing phase, the contractile element (CE) maintains a near isometric action while the series elastic (tendinous) element first stretches as the knee extends, and then recoils causing the swing leg to forcefully retract prior to ground contact. Although modelling studies showed some active lengthening of the contractile (muscular) element during the mid-swing phase of high-speed running, we argue that the increasing distance between the attachment points should not be interpreted as an eccentric action of the CE due to the effects of muscle slack. Therefore, there may actually be no significant eccentric, but rather predominantly an isometric action of the hamstrings CE during the swing phase of high-speed running when the attachment points of the hamstrings are moving apart. Based on this, we propose that isometric rather than eccentric exercises are a more specific way of conditioning the hamstrings for high-speed running.

Speed control of induction motor using fuzzy recursive least squares technique

OpenAIRE

Santiago Sánchez; Eduardo Giraldo

2008-01-01

A simple adaptive controller design is presented in this paper, the control system uses the adaptive fuzzy logic, sliding modes and is trained with the recursive least squares technique. The problem of parameter variation is solved with the adaptive controller; the use of an internal PI regulator produces that the speed control of the induction motor be achieved by the stator currents instead the input voltage. The rotor-flux oriented coordinated system model is used to develop and test the c...

Low-Speed Cooperative Car-Following Fuzzy Controller for Cybernetic Transport Systems

OpenAIRE

Milanés , Vicente; Marouf , Mohamed; Pérez Rastelli , Joshué; Gonzalez Bautista , David; Nashashibi , Fawzi

2014-01-01

International audience; — This paper describes the development of a Coop-erative Adaptive Cruise Control (CACC) for the future urban transportation system at low-speed. The control algorithm was evaluated using two Cybecars as prototype vehicles. A longitu-dinal response model for the vehicles was developed to design the CACC system. The control algorithm was implemented on a fuzzy logic-based controller that has been tuned to minimize a cost function in order to get a trade-off between a pro...

Ensuring Control Processes Quality in Relay System Without Speed Sensor

Directory of Open Access Journals (Sweden)

R. P. Simonyants

2014-01-01

Full Text Available The paper considers topical issues of constructing relay systems to control spacecraft attitude and stabilization with no speed sensors (SS owing to use of internal feedback (IF. To research this system by point methods, e.g. a point mapping method, is difficult because of the need to solve the transcendent equations containing parameters both of control object and of IF. We propose the “diagram of superimpositions" (DS method based on topological transformations of the phase space and introduction of a relative time, which enables us to solve engineering problems in analysis and synthesis effectively.The concept of the method is based on the assertion that there is an unambiguous dependence between quality of dynamical regimes in the control system and characteristics of IF transition function. To justify the method a simplified mathematical model of spacecraft motion is applied. The following conditions are accepted: perturbations can be neglected; when the control function is activated, the signal of IF is equal to zero. To the phase surfaces are applied topological symmetry transformations, alignment and projection onto the plane with one of its coordinates being the relative time.The paper gives specific examples of systems with aperiodic feedback (AF for two versions of parameters to satisfy the requirements: I – in quality of self-oscillation mode (by pulse width in the limit cycle; II – in quality of transition process (lack of sliding modes. It is shown that the requirements II and I are contradictory for the system with AF while the sliding modes are unacceptable.It is shown that DS can be used to synthesize the IF to meet requirements of both steady and transient processes consistently. Using the IF it is possible to implement the shutdown laws of the control action on the DS without SS, the same as in case of using the SS. It is shown that in sliding modes transient processes poor in quality can be completely eliminated by

An analytical investigation on the valve and centrifugal pump speed control with a constant differential pressure across the valve

International Nuclear Information System (INIS)

Jung, B. R.; Joo, K. I.; Lee, B. J.; Baek, S. J.; Noh, T. S.

2003-01-01

A valve opening and centrifugal pump speed control was investigated analytically in a simple pumping system where the differential pressure across the control valve is maintained constant over the required flow range. The valve control program was derived analytically only as a function of the required flow rate to maintain the constant differential pressure across the valve. The centrifugal pump speed control program was also derived analytically for the required flow rate for the constant differential pressure across the control valve. These derivations theoretically show that the independent control is possible between the valve and pump speed in a system with a constant valve pressure drop. In addition, it was shown that a linear pump speed control is impossible in maintaining the constant valve pressure drop

Design of high-speed ECT and ERT system