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International Conference on Applied Electronics, AE

作者： Jakub Eichler Miloslav Košek Miroslav Novak Institute of Mechatronics and Computer Engineering Technical University of Liberec Liberec Czech Republic

This paper presents the implementation of the Preisach hysteresis model of a soft magnetic material. The model application is especially useful in the study of transition effects in power transformers like an inrush current or a ferroresonance. The main problem in the use of the Preisach model is to find a suitable weighting function. We considered two basic methods: estimation and systematic derivation. Application of both the methods revealed that the systematic method leads to a better agreement with the experiment. However both results are applicable for investigation of annealed grain oriented steel in transformer core.

关键词： Magnetic hysteresis Soft magnetic materials Magnetic moments Approximation methods Systematics Saturation magnetization Integrated circuit modeling

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Multiple model predictive control of grid connected solid oxide fuel cell for extending cell life time

Multiple model predictive control of grid connected solid ox...

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Mediterranean Conference on Control and Automation (MED)

作者： R. Horalek J. Hlava Institute of Mechatronics and Computer Engineering Technical University of Liberec Czech Republic

Solid oxide fuel cells (SOFC) can be used for both distributed electricity generation and cogeneration purposes. They have higher efficiency and certain other advantages over proton exchange membrane fuel cells. However an important weak point of SOFC cells is their lifetime and durability. In particular, high temperature and fuel utilization variations resulting from load changes contribute to stack damage and significantly decrease the cell lifetime. In this paper, a model predictive control scheme for extending the cell lifetime is proposed. It makes use of the ability of predictive control to respect range and rate constraints. SOFC stack damage is prevented by satisfying temperature, fuel utilization and air utilization operational constraints. The cell behavior is significantly nonlinear. However as nonlinear MPC still has many issues, the nonlinearity was accounted for by using MPC scheme based on multiple linear models. The control scheme considers grid connected fuel cell and the main control objective is to deliver the desired power while respecting all constraints related to cell lifetime. Simulation results show that proposed life extending controller is able to control SOFC in a wide operational range and it gives good tradeoff between the cell life time and control system performance.

关键词： Fuels Fuel cells Control systems Inverters Atmospheric modeling Measurement Predictive control

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The concept of a highly efficient powertrain for an electric vehicle with respect to vehicle driving dynamics

The concept of a highly efficient powertrain for an electric...

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International Conference on Electrical Drives and Power Electronics (EDPE)

作者： Pavel Jandura Josef Břoušek Martin Bukvic Institute of Mechatronics and Computer Engineering Technical University of Liberec Liberec Czech Republic Department of Vehicles and Engines Technical University of Liberec Liberec Czech Republic

This article discusses the characteristics of several concepts of powertrains suitable for use in purely electric vehicles. Attention is paid to how the given system affects the driving dynamics of the vehicle and especially the overall drive efficiency based on the defined driving cycle. The introduction presents the specific types of powertrain used in modern mass-produced electric vehicles. The following sections describe the properties of selected devices, demonstrated using an example of a high-performance virtual electric motor. The dependence of the available tractive effort, the attainable acceleration and the overall efficacy of the powertrain with one or two motors are depicted graphically.

关键词： Mechanical power transmission Vehicles Wheels Vehicle dynamics Electric motors Gears Torque

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100 years of piezoelectric materials in acoustics: From a sonar to active metasurfaces

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Proceedings of Meetings on Acoustics 2016年第1期28卷

作者： Pavel Mokrý 1Institute of Mechatronics and Computer Engineering Technical University of Liberec Liberec Czech Republic pavel.mokry@tul.cz

Since the discovery of the quartz ultrasound generator by Paul Langevin in 1917, piezoelectric materials have been successfully applied to many acoustic devices, which have greatly improved our lives. Nowadays, the piezoelectric transducers can employ a vast set of piezoelectric materials such as single crystals, ceramics, polymers, biopolymers, macro fiber composites, ferroelectrets, flexoelectric materials and some others. In this paper, a brief review of the use of piezoelectric materials in electroacoustic transducers will be given. Emphasis will be put on the modern applications of piezoelectric materials to the acoustics, especially on the method of active control of their elastic properties by means of active shunt circuits. The recent application of this method allowed the construction of so called active acoustic metamaterials (AAMM) and metasurfaces. The AAMMs based on the piezoelectric transducers offer the fabrication of efficient sound shielding structures with a low weight, a large area and a thickness which can be smaller than the wavelength of a sound wave. It is evident that such sound-isolation structures are beneficial to construction of devices with severely restricted weight constraints.

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Improving convergence properties of a differential evolution algorithm

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AIP Conference Proceedings 2016年第1期1789卷

作者： Roman Knobloch Jaroslav Mlynek Radek Srb Department of Mathematics FP Technical University of Liberec Studentska 2 461 17 Liberec The Czech Republic Institute of Mechatronics and Computer Engineering Technical University of Liberec Studentska 2 461 17 Liberec The Czech Republic

The differential evolution is a popular and efficient way to solve complicated optimization tasks with many variables and constraints. In this article we study the ability of the differential evolution algorithms to attain the global minimum of the cost function. We demonstrate that although often declared as a global optimizer the classic differential evolution algorithm does not guarantee the convergence to the global minimum. To improve this weakness we design a modification of the classic differential evolution algorithm to enrich the diversity of its populations. This modification limits the premature convergence to local minima and ensures the asymptotic global convergence. We tested the modified algorithm in numerical experiments and compared the efficiency in finding the global minimum for the classic and modified algorithm. The modified algorithm is significantly more efficient with respect to the global convergence than the classic algorithm.

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Influnce of driving style of a tram driver on the tram's energy consumption

Influnce of driving style of a tram driver on the tram's ene...

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International Conference on Electrical Drives and Power Electronics (EDPE)

作者： Jiří Kubín Želmíra Ferková Institute of Mechatronics and Technical Informatics Technical University of Liberec Liberec Czech Republic Dept. of Electrical Engineering and Mechatronics Technical University of Košice Košice Slovak Republic

A typical feature of city tram transportation is increasing its effectivity. The main effort of public transportation companies is seeking savings for decreasing the energy intensity of mass transit. During operative measurement of power consumption in the tram cars it was found that on the whole the tram energy consumption have well-known influences such as tram occupancy, use of heating etc., and less known factors such as e.g. driving style of driver. We would like to estimate how much more energy is consumed by aggressive driving style of driver. Because it is impossible to ensure the same conditions at passing the same track, we concentrated on devising a tram car model that quantifies the difference of consumed energy in case normal driving style of the driver and in case of dynamic driving style of the driver. Because we use mathematical model, we can set the other conditions such as vehicle occupancy, the number of accelerations, stoppings etc. on the same values.

关键词： Traction motors Acceleration Vehicles Energy consumption Force Mathematical model Friction

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Retrofit LED Lamps: Photometric Flicker Analysis

Retrofit LED Lamps: Photometric Flicker Analysis

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IEEE Industry Applications Society Annual Meeting

作者： Leos Kukacka Pascal Dupuis Georges Zissis Milan Kolar Institute of Mechatronics and Computer Engineering FMIIS Technical University of Liberec Universite de Toulouse LAPLACE UMR 5213 (CNRS INPT UPS)

ISBN: (纸本)9781479983957

The paper exposes the topic of LED lamps photometric flicker. Aim of the paper is to evaluate the flicker of contemporary devices. A sample of commercially available LED retrofit lamps is analysed in terms of the photometric flicker under ideal sinusoidal power supply conditions. Therefore the flicker described here is not a power quality issue, but a characteristic of the analysed lamps. The flicker level is compared to an incandescent lamp. As shown in the paper, some of the LED lamps show very high flicker level.

关键词： LED Lamp Power Quality Flicker

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Extra low voltage DC grid LED lighting systems: photometric flicker analysis

Extra low voltage DC grid LED lighting systems: photometric ...

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IEEE International Workshop of Electronics, Control, Measurement, Signals and their application to mechatronics (ECMSM)

作者： Leos Kukacka Pascal Dupuis Georges Zissis Jan Kraus Milan Kolar LAPLACE UMR 5213 (CNRS INPT UPS) Université de Toulouse Toulouse France Institute of Mechatronics and Computer Engineering FMIIS Technical University of Liberec Czech republic Technicka univerzita v Liberci Liberec Liberec Region CZ

The paper exposes the topic of LED lighting systems flicker. The topic of extra low voltage LED lamps flicker has not been much discussed yet. A variety of commercially available extra low voltage (ELV) lamps were tested with respect to the light flicker produced when powered by nominal DC voltage. The same measurement is repeated with distorted and fluctuating voltage. Reverse engineering methods were employed to reveal the link between the observed flicker level and the electronic ballast topology used in the lamps. The paper aims to formulate demands on DC LED lamp ballasts to avoid flickering.

关键词： Electronic ballasts LED lamps Frequency measurement Voltage fluctuations Low voltage

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Robust control design for positioning of an unactuated surface vessel

Robust control design for positioning of an unactuated surfa...

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IEEE/RSJ International Conference on Intelligent Robots and Systems

作者： B. Bidikli E. Tatlicioglu E. Zergeroglu Department of Mechatronics Engineering Izmir Katip Celebi University Izmir Turkey Department of Electrical & Electronics Engineering Izmir Institute of Technology Izmir Turkey Department of Computer Engineering Gebze Technical University Gebze Kocaeli Turkey

In this paper, a robust controller is designed to achieve accurate positioning of an unactuated surface vessel by using multiple unidirectional tugboats. After initially locating opposing tugboats to specific configurations, the control problem is transformed into a second order system with an uncertain non-symmetric input gain matrix. Upon applying a matrix decomposition, a robust controller is proposed. Detailed stability analysis ensured asymptotic tracking. Numerical simulation results demonstrate the efficiency of the proposed controller.

关键词： Matrix decomposition Symmetric matrices Stability analysis Robustness Robust control Force

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Nonlinear Robust Control of a Levitation System with Hybrid Electromagnets

Nonlinear Robust Control of a Levitation System with Hybrid ...

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IEEE Annual Conference on Decision and Control

作者： Beytullah Okur Erkan Zergeroglu Kadir Erkan Department of Electronics Engineering Gebze Institute of Technology 41400 Gebze Kocaeli Turkey Department of Computer Engineering Gebze Institute of Technology 41400 Gebze Kocaeli Turkey Department of Mechatronics Engineering Yildiz Technical University 34349 Besiktas Istanbul Turkey

ISBN: (纸本)9781479978878

In this study;we present a model based robust controller for a one degree-of-freedom magnetic levitation system with hybrid electromagnets. Nonlinear equations of the magnetic force model have been used to develop the model based controller. The proposed controller can handle parametric uncertainties and only requires air gap and coil current measurements. The output of the controller is the voltage input of the coils and back-stepping procedure have been applied to reach the voltage dynamics over current dynamics. The stability and convergence of the closed loop system have been proved via Lyapunov-type arguments. Simulation results are presented to illustrate the performance of the proposed robust controller.

关键词： Magnetic levitation systems Robust controllers Electromagnets Nonlinear robust control Controllers output controller Closed loop systems Magnetic force

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