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Annual IEEE Conference on Power Electronics Specialists (PESC)

作者： L. Palma P. Enjeti Department of Electrical Engineering Universidad de Concepciòn Concepcion Chile Power Electronics & Fuel Cell Power Systems Laboratory Department of Electrical & Computer Engineering Texas A and M University College Station TX USA

Fuel cell stacks produce a DC output with a 2:1 variation in output voltage from no load to full load. The output voltage of each fuel cell is about 0.4 V at full load and several of them are connected in series to construct a stack. An example 100 V fuel cell stack consists of 250 cells in series and to produce 300 V at full load requires 750 cells stacked in series. Since fuel cells actively convert the supplied fuel to electricity, each cell requires proper distribution of fuel, humidification, coupled with water/thermal management needs. With this added complexity stacking more cells in series decreases the reliability of the system. For example, in the presence of bad or mal-performing cell/cells in a stack, uneven heating coupled with variations in cell voltages may occur. Continuous operation under these conditions may not be possible or the overall stack output power is severely limited. In this paper a modular fuel cell powered by a modular DC-DC converter is proposed. The proposed concept electrically divides the fuel cell stack into various sections, each powered by a DC-DC converter. The proposed modular fuel cell powered by modular DC-DC converter eliminates many of these disadvantages, resulting in a fault tolerant system. A design example is presented for a 150 W, three section fuel cell stack and DC-DC converter topology. Experimental results obtained on a 150 W, three section PEM fuel cell stack powered by a modular DC-DC converter are discussed.

关键词： Fuel cells DC-DC power converters Voltage Thermal management Energy conversion Energy management Load management Stacking Power system reliability Heating

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Making the power grid more intelligent

Making the power grid more intelligent

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iREP Symposium on Bulk Power System Dynamics and Control

作者： Salman Mohagheghi Ronald G. Harley Ganesh K. Venayagamoorthy School of Electrical and Computer Engineering Georgia Institute of Technology Intelligent Power Infrastructure Consortium Atlanta GA USA Department of Electrical and Computer Engineering Real-Time Power and Intelligent Systems Laboratory University of Missouri Rolla MO USA

Summary form only given. This paper focuses on the applications of intelligent techniques for improving the performances of the power system controllers. Intelligent control techniques lay the foundation of the next generation of nonlinear controllers and have the advantage of further improving the controller's performance by incorporating heuristics and expert knowledge into its design. Most of these techniques are independent of any mathematical model of the power system, which proves to be a considerable advantage.

关键词： Power grids Power system modeling Control systems Power system dynamics Power system control Power systems Power system reliability Intelligent networks Humans Three-term control

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RESONANT TERAHERTZ DETECTION ANTENNA UTILIZING PLASMA OSCILLATIONS IN LATERAL SCHOTTKY DIODE

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International Journal of High Speed Electronics and systems 2007年第3期17卷 539-546页

作者： AKIRA SATOU VICTOR RYZHII TAIICHI OTSUJI MICHAEL S. SHUR Computer Solid State Physics Laboratory University of Aizu Aizu-Wakamatsu 965-8580 Japan Research Institute of Electrical Communication Tohoku University Sendai 980-8577 Japan Department of Electrical Computer and Systems Engineering Rensselaer Polytechnic Institute Troy NY 12180 USA

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Real-time full-field 3-D surface-shape measurement using off-the-shelf components and a single processor

Real-time full-field 3-D surface-shape measurement using off...

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International Conference on 3D Imaging, Modeling, Processing, Visualization and Transmission (3DIMPVT)

作者： Peirong Jia Jonathan Kofman Chad English Computer Vision and Systems Laboratory Department of Electrical and Computer Engineering Laval University QUE Canada Department of Mechanical Engineering University of Ottawa Ottawa ONT Canada Department of Systems Design Engineering University of Waterloo Waterloo ONT Canada Neptec Design Group Limited Kanata ONT Canada

Phase-shifting fringe-projection methods have been increasingly used for three-dimensional (3D) object surface modeling to permit full-field measurement. This paper presents a real-time full-field high-resolution 3D surface-shape measurement system implemented with an efficient 3D shape measurement pipeline and triangular-pattern phase-shifting based on off-the-shelf components, software synchronization and a single computer-processor. The system projects computer-generated fringe patterns with a triangular intensity profile onto an object via a Digital Light Processing (DLP) projector. The projected patterns are electronically shifted and a CCD camera synchronized with the DLP projector by software captures the images from another direction. The captured images are processed by a single computer to reconstruct the 3D shape using triangular-pattern phase-shifting algorithms, and the model is displayed in real time. The 3D shape acquisition system achieved a speed of 5.6 fps for an image size of 648times494 pixels using the two-step triangular-pattern phase-shifting method, without any hardware synchronization or dual processing.

关键词： Phase measurement Shape measurement Real time systems Software measurement Pipelines Charge coupled devices Charge-coupled image sensors computer displays Image reconstruction Pixel

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A Hybrid systems Approach to Trajectory Tracking Control for Juggling systems

A Hybrid Systems Approach to Trajectory Tracking Control for...

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Proceedings of the 46th IEEE Conference on Decision and Control, Pages 5971-6447

作者： Ricardo G. Sanfelice Andrew R. Teel Rodolphe Sepulchre Laboratory for Information and Decision Systems Massachusetts Institute of Technology MA USA Department of Electrical & Computer Engineering University of California Santa Barbara CA USA Department of Electrical and Computer Science Université de Liège Liege Belgium

ISBN: (纸本)9781424414970;1424414970

From a hybrid systems point of view, we provide a modeling framework and a trajectory tracking control design methodology for juggling systems. We present the main ideas and concepts in a one degree-of-freedom juggler, which consists of a ball bouncing on an actuated robot. We design a hybrid control strategy that, with only information of the ball's state at impacts, controls the ball to track a reference rhythmic pattern with arbitrary precision. We extend this hybrid control strategy to the case of juggling multiple balls with different rhythmic patterns. Simulation results for juggling of one and three balls with a single actuated robot are presented.

关键词： hybrid systems Ball Device Component control strategy trajectory tracking hybrid control Robot

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Speed Control of a Dual Stator Winding Induction Machine

Speed Control of a Dual Stator Winding Induction Machine

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Annual IEEE Conference on Applied Power Electronics Conference and Exposition (APEC)

作者： Olorunfemi Ojo Zhiqiao Wu Department of Electrical and Computer Engineering/Center for Energy Systems Research Laboratory for Electric Machines and Power Electronics Tennessee Technological University Cookeville TN USA

A dual stator winding induction machine having two stator winding sets and a squirrel-cage rotor structure has been identified as having a good low speed controllability. This paper therefore presents the speed control of a dual stator winding machine using the concepts of indirect rotor field orientation and input-output linearization formalism. With a torque partition coefficient, it is possible to vary the electromagnetic torques generated by the two stator windings, which at low speeds makes it possible for one winding set to be generating leading to an improvement of the flux linkage estimation. Simulation results are presented for various command speed profiles including zero speed operation showing the efficacy of the torque partition coefficient even at very low speed operation. This possibility of operating at low speeds including zero using model based flux estimation schemes set forth in this paper is one of the benefits of the dual stator winding induction machinery.

关键词： Velocity control Stator windings Induction machines Frequency Rotors Couplings Torque control Voltage control Power generation Pulsed power supplies

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Blind Sparse-Nonnegative (BSN) Channel Identification for Acoustic Time-Difference-of-Arrival Estimation

Blind Sparse-Nonnegative (BSN) Channel Identification for Ac...

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IEEE Workshop on Applications of Signal Processing to Audio and Acoustics

作者： Yuanqing Lin Jingdong Chen Youngmoo Kim Daniel D. Lee GRASP Laboratory Department of Electrical and Systems Engineering University of Pennsylvania Philadelphia PA USA Bell Laboratories Alcatel-Lucent Murray Hill NJ USA Electrical and Computer Engineering Department Drexel University Philadelphia PA USA

Estimating time-difference-of-arrival (TDOA) remains a challenging task when acoustic environments are reverberant and noisy. Blind channel identification approaches for TDOA estimation explicitly model multipath reflections and have been demonstrated to be effective in dealing with reverberation. Unfortunately, existing blind channel identification algorithms are sensitive to ambient noise. This paper shows how to resolve the noise sensitivity issue by exploiting prior knowledge about an acoustic room impulse response (RIR), namely, an acoustic RIR can be modeled by a sparse-nonnegative FIR filter. This paper shows how to formulate a single-input two-output blind channel identification into a least square convex optimization, and how to incorporate the sparsity and nonnegativity priors so that the resulting optimization remains convex and can be solved efficiently. The proposed blind sparse-nonnegative (BSN) channel identification approach for TDOA estimation is not only robust to reverberation, but also robust to ambient noise, as demonstrated by simulations and experiments in real acoustic environments.

关键词： Time difference of arrival Acoustic noise Finite impulse response filter Microphones Working environment noise Acoustic reflection Noise robustness Acoustic applications Reverberation Acoustic signal processing

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Adaptive Critic Design Based Neuro-Fuzzy Controller for a Static Compensator in a Multimachine Power System

Adaptive Critic Design Based Neuro-Fuzzy Controller for a St...

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IEEE General Meeting Power& Energy Society

作者： Salman Mohagheghi Ganesh K. Venayagamoorthy Ronald G. Harley School of Electrical and Computer Engineering Georgia Institute of Technology Intelligent Power Infrastructure Consortium Atlanta GA USA Real-Time Power and Intelligent Systems Laboratory Department of Electrical and Computer Engineering University of Missouri Rolla Rolla MO USA

Summary form only given. This paper presents a novel nonlinear optimal controller for a static compensator (STATCOM) connected to a power system, using artificial neural networks and fuzzy logic. The action dependent heuristic dynamic programming (ADHDP), a member of the adaptive critic designs (ACD) family, is used for the design of the STATCOM neuro-fuzzy controller. This neuro-fuzzy controller provides optimal control based on reinforcement learning and approximate dynamic programming, and can effectively perform in the presence of noise and uncertainties. Using a proportional-integrator approach the proposed controller is capable of dealing with actual rather than deviation signals. The STATCOM is connected to a multimachine power system in order to provide voltage support during the steady state performance of the power system and also improve the dynamic stability of the network during faults and disturbances. Two multimachine power systems are considered in this study: a 10-bus 2-generator system and a 45-bus 10-generator system, where the latter is a section of the Brazilian power grid. Simulation results are provided to show that the proposed controller outperforms a conventional PI controller in large scale faults as well as small disturbances.

关键词： Programmable control Adaptive control Control systems STATCOM Power systems Power system dynamics Power system stability Optimal control Automatic voltage control Power system faults

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Neural-network-based intelligent control for improving dynamic performance of FACTS devices

Neural-network-based intelligent control for improving dynam...

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iREP Symposium on Bulk Power System Dynamics and Control

作者： Wei Qiao Ronald G. Harley Ganesh K. Venayagamoorthy Intelligent Power Infrastructure Consortium School of Electrical and Computer Engineering Georgia Institute of Technology Atlanta GA USA Real-Time Power and Intelligent Systems Laboratory Department of Electrical and Computer Engineering University of Missouri Rolla Rolla MO USA

Flexible AC transmission system (FACTS) devices are widely recognized as powerful controllers to improve the dynamic performance and stability of power systems. The standard FACTS controllers are linear controllers designed around a specific operating point from a linearized system model with fixed parameters. However, at other operating points their performance degrades. Neural-network-based nonlinear intelligent control offers an attractive approach to overcome the drawbacks of the linear controllers. This paper presents two different neural-network-based intelligent control architectures, i.e., indirect adaptive neurocontrol and adaptive critic design based optimal neurocontrol, for designing the external control of an SSSC FACTS device. Simulation studies are carried out to evaluate the proposed nonlinear intelligent controllers on single machine infinite bus as well as multi-machine power systems. Results show that the proposed intelligent controls improve the dynamic performance of the SSSC and the associated power network.

关键词： Intelligent control Power system dynamics Flexible AC transmission systems Power system stability Power system modeling Programmable control Adaptive control Power system simulation Control systems Nonlinear dynamical systems

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Analysis of DC-DC Conversion for Energy Harvesting systems Using a Mixed-Signal Sliding-Mode Controller

Analysis of DC-DC Conversion for Energy Harvesting Systems U...

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Annual IEEE Conference on Power Electronics Specialists (PESC)

作者： Nathaniel J. Guilar Rajeevan Amirtharajah Paul Hurst University of California Center Sacramento Sacramento CA US Micropower Circuits and Systems Group Department of Electrical and Computer Engineering University of California Davis CA USA Solid-State Research Laboratory Department of Electrical and Computer Engineering University of California Davis CA USA

Increasing efficiencies in electronic devices have opened the door for energy harvesters to power wireless systems by scavenging energy from solar, thermal, or mechanical sources. The design of an efficient power supply that can regulate scavenged energy to produce stable voltages for multiple loads is presented here. To limit energy dissipation and increase the flexibility of the regulator, a discrete-time sliding-mode controller is presented. The performance of sliding-mode controllers is hard to predict because their switching frequency and output voltage ripple are dependent on duty cycle and load conditions. An analytical approach for the closed-loop steady- state behavior of a discrete-time sliding-mode controller is presented here. The proposed analytical solution matches measured results to within 4% for duty cycles ranging between 0.1 and 0.9.

关键词： Sliding mode control Control systems Regulators Finite impulse response filter Voltage Pulse width modulation Samarium Power supplies Circuits Passive filters

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