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distributed and backstepping boundary controls to achieve IDA-PBC design

IFAC-PapersOnLine 2015年第1期28卷 482-487页

作者： Vu, N.M. Trang Lefèvre, L. Nouailletas, R. Univ. Grenoble Alpes LCIS F-26902 France CEA DSM IRFM STEP CEA Cadarache France

An IDA-PBC-like control synthesis for infinite dimensional port Hamiltonian systems is investigated. As for the finite dimensional case, a feedback control transforms the original model into a closed loop target Hamiltonian model. Both distributed control and boundary control are used. The finite rank distributed control is determined to solve an average IDA-PBC matching equation. A backstepping boundary control is used to stabilize the matching error. The control model chosen to illustrate the approach is the so-called resistive diffusion equation for the radial diffusion of the poloidal magnetic flux. © 2015, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.

关键词： Hamiltonians Backstepping distributed parameter control systems Back stepping controls distributed parameter Ida pbc Plasma control Port Hamiltonian systems

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DISTRIBUTION OF THE HEAT AND CURRENT FLUXES IN GAS TUNGSTEN ARCS

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METALLURGICAL TRANSACTIONS B-PROCESS METALLURGY 1985年第4期16卷 841-846页

作者： TSAI, NS EAGAR, TW MIT DEPT MAT SCI & ENGNCAMBRIDGEMA 02139

The distribution of heat flux on a water-cooled copper anode as a function of welding process parameters has been determined experimentally following an experimental technique developed previously. The results indicate that arc length is the primary variable governing heat distribution and that the distribution is closely approximated by a gaussian function. The half width of the heat flux is defined by a distribution parameter, σ, which was determined from the experimental data and is expressed as a function of arc length, current, and electrode tip angle. The distribution parameter, σ, increases from 1.5 mm to 3.6 mm as the arc length increases from 2 mm to 9 mm for a 100 A arc. The experimental data also show that arc energy transfer efficiency is greater than 80 pct on the water-cooled anode which is much higher than has been measured in the presence of a molten metal pool. For this reason, it is believed that the distribution of the heat flux and not the magnitude is the most useful information obtained in this study. The effect of helium additions to the argon on the heat distribution is also reporte

关键词： ELECTRIC ARC Arc length welding process parameters Heat flux copper anode half-value width flux arcs distributed parameter liquid metals arc heat chip angle TUNGSTEN INERT GAS WELDING Heat distribution

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Controlled Chaos Based on Tellegen's Principle in Electric Power Systems - Basic Approach

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IFAC-PapersOnLine 2016年第27期49卷 370-375页

作者： Stork, M. Mayer, D. Hrusak, J. Department of Applied Electronics and Telecommunications UWB Plzen30614 Czech Republic Department of Theoretical Electric UWB Plzen30614 Czech Republic

The paper deals with a new problem of physical correctness detection in the area of strictly causal system representations. The proposed approach to the problem solution is based on generalization of Tellegen's theorem well known from electrical engineering. The novelty of this approach is that it is based on the abstract state space energy for real linear, nonlinear and chaotic systems e.g. electrical circuits and power lines with distributed parameters. Consequently, mathematically as well as physically correct results are obtained. Some known and often used system representation structures are discussed from the developed point of view as an addition. The examples are also included. © 2016

关键词： Electric power system control Chaotic systems Electric power systems Nonlinear systems Causal systems distributed parameter Electrical circuit Problem solutions Simulations Tellegen Tellegen's principle Tellegen's theorems

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Predictive Protective Control for Flexible Energy System

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IFAC-PapersOnLine 2018年第6期51卷 1-6页

作者： Ozana, S. Pies, M. Department of Cybernetics and Biomedical Engineering Faculty of Electrical Engineering and Computer Science VSB-Technical University of Ostrava 17.listopadu 15 Ostrava Czech Republic

The paper deals with the predictive control applied to flexible cogeneration energy system (FES). The FES was designed and developed by the VITKOVICE POWER ENGINEERING joint-stock company and represents a new solution of decentralized cogeneration energy sources. In FES, the heating medium is flue gas generated by combustion of a solid fuel. The heated medium is power gas, which is a gas mixture of air and water steam. Power gas is superheated in the main heat exchanger and led to gas turbines. To protect the main heat exchanger against damage by overheating, the novel predictive protective control based on the mathematical model of exchanger was developed. The paper describes the principle, the design and simulation of the predictive protective method applied to main heat exchanger of FES. © 2018

关键词： Gases Cogeneration plants Fuels Gas turbines Heat exchangers Design and simulation distributed parameter Energy systems Heating medium Joint stock companies Power engineering Predictive control simulation

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Robust trend estimation of observed German precipitation

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THEORETICAL AND APPLIED CLIMATOLOGY 2008年第1-2期93卷 107-115页

作者： Troemel, S. Schoenwiese, C. D. Univ Bonn Inst Meteorol D-53121 Bonn Germany Goethe Univ Frankfurt Inst Atmosphere & Environm Frankfurt Germany

Trends in climate time series are habitually estimated on the basis of the least-squares method. This estimator is optimal if the residuals follow the Gaussian distribution. Unfortunately, only a small number of observed climate time series fulfil this assumption. This work introduces a robust method for trend analyses of non-Gaussian climate variables. Robust trend analyses as well as probability assessments of extreme events (Tromel and Schonwiese 2006) represent an application of the generalized time series decomposition technique. Tromel (2005) and Tromel and Schonwiese (2005) applied this decomposition technique to monthly precipitation sums from a German station network of 132 time series covering 1901-2000 in order to achieve a statistical modeling of the time series. The time series under consideration can be interpreted as a realization of a Gumbel-distributed random variable with time-dependent scale and location parameter. More precisely, each observed value can be seen as one possible realization of the estimated probability density function (PDF) with the location and the scale parameter of the respective time step. Consequently, the expected value of the Gumbel-distributed random variable can be estimated for every time step of the observation period and the statistical modeling represents an alternative approach to estimate trends in observational precipitation time series. The method is robust with respect to observed high precipitation values. The influence of relatively high precipitation sums is not larger than justified from a statistical point of view and changes in all parameters (here location and scale parameter) of the distribution can be taken into account. Monte-Carlo-simulations demonstrate the smaller mean squared error of the trend estimator using the statistical modeling. The least-squares estimator often shows a positive bias, while the method introduced provides robust monthly trend estimates taken into account the statistical charac

关键词： FORWARD BIAS scale parameter precipitation (meteorology) location parameter Time series distributed parameter statistical models (nuclear)

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Deformation Broadening and the Fine Structure of Spectral Lines in Optical Spectra of Dielectric Crystals Containing Rare-Earth Ions

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PHYSICS OF THE SOLID STATE 2019年第5期61卷 795-801页

作者： Abishev, N. M. Baibekov, E. I. Malkin, B. Z. Popova, M. N. Pytalev, D. S. Klimin, S. A. Kazan Volga Reg Fed Univ Kazan Russia Russian Acad Sci Inst Spect Troitsk 108840 Russia

The procedure of calculation of the spectral line shape in optical spectra of rare-earth ions in crystals with the inclusion of random deformations of an elastically anisotropic crystal lattice caused by point defects is developed. The distribution function of components of the random strain tensor in the case of a low defect concentration is obtained as the generalized six-dimensional Lorentz distribution. The distribution function parameters are represented by the integral functional of the strain tensor components on a sphere of unit radius containing an isotropic point defect in its center. The numerical calculations of the strain tensors induced by point defects and the parameters of the distribution functions of random strains in LiLuF4 and LaAlO3 crystals have been performed. The calculated envelope with the doublet structure corresponding to the (2)(H-3(4)) (34)(H-3(5)) singlet-doublet transition in the absorption spectrum of Pr3+ ions in the LiLuF4 crystal agrees well with the data of the measurements.

关键词： strain tensor Spectral lines point defects data measurement fine structure crystals optical spectra Absorption spectra Ions distributed parameter spectral line width rare earth ion carburizing numerical calculation Distribution function

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distributed Weighted Least-Squares Estimation for Power Networks

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IFAC-PapersOnLine 2015年第28期48卷 562-567页

作者： Marelli, Damián Ninness, Brett Fu, Minyue School of Electrical Engineering and Computer Science University of Newcastle University Drive Callaghan NSW 2308 Australia Department of Control Science and Engineering Zhejiang University 38 Zhe Da Road Hangzhou310007 China

The paper presents a fully distributed scheme to optimal parameter estimation, withapplication in multi-area interconnected power systems. In this scheme, each area performs itsown local parameter estimation based on low-dimensional local and boundary measurementsas well as the estimate of boundary parameters from its neighbors. We show, under certainassumptions, that the distributed estimation scheme provides the same accurate unbiasedestimate as the centralized weighted least-squares estimate with finite time convergence. Thedistributed estimation scheme is robust to communication link failures, delays, and asynchronismof control centers in different areas. A simulation using the IEEE 118-bus system is included todemonstrate the performance. © 2015

关键词： parameter estimation Electric power transmission networks Standby power systems distributed estimation distributed parameter Finite time convergence Least squares estimation Optimal parameter estimation Smart power applications Weighted least squares Weighted least squares estimation

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Size distribution and chemical composition of marine aerosols: a compilation and review

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TELLUS SERIES B-CHEMICAL AND PHYSICAL METEOROLOGY 2000年第4期52卷 1104-1122页

作者： Heintzenberg, J Covert, DC Van Dingenen, R Inst Tropospher Res D-04318 Leipzig Germany Univ Washington Seattle WA 98195 USA Commiss European Communities Joint Res Ctr Inst Environm I-21020 Ispra VA Italy

Some 30 years of physical and chemical marine aerosol data are reviewed to derive global-size distribution parameters and inorganic particle composition on a coarse 15 degrees x 15 degrees grid. There are large gaps in geographical and seasonal coverage and chemical and physical aerosol characterisation. About 28% of the grid cells contain physical data while there are compositional data in some 60% of the cells. The size distribution data were parametrized in terms of 2 submicrometer log-normal distributions. The sparseness of the data did not allow zonal differentiation of the distributions. By segregating the chemical data according to the major aerosol sources, sea salt, dimethylsulfide, crustal material, combustion processes and other anthropogenic sources, much information on mass concentrations and contribution of natural and anthropogenic sources to the marine aerosol can be gleaned from the data base. There are significant meridional differences in the contributions of the different sources to the marine aerosol. Very clearly, we see though that the global marine surface atmosphere is polluted by anthropogenic sulfur. Only in the case of sulfur components did the coverage allow the presentation of very coarse seasonal distributions which reflect the spring blooms in the appropriate parts of the oceans. As an example of the potential value in comparing the marine aerosol data base to chemical transport models, global seasonal meridional MSA distributions were compared to modelled MSA distributions. The general good agreement in mass concentrations is encouraging while some latitudinal discrepancies warrant further investigations covering other aerosol components such as black carbon and metals.

关键词： MAJOR SYSTEM ACQUISITION chemical compounds Coverage aerosols chemical transport distributed parameter physical data Database

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ADDITION OF A LARGE NUMBER OF IDENTICAL ANGULAR MOMENTA - STATISTICAL DISTRIBUTIONS

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JOURNAL OF PHYSICS A-MATHEMATICAL AND GENERAL 1979年第12期12卷 2329-2335页

作者： MIKHAILOV, VV Kazan Phys.&Tech. Inst. Acad. of Sci. Kazan USSR

The quantum mechanical addition of an arbitrary (very large) number of identical angular momenta is considered. The resulting states jm usually occur many times. The corresponding multiplicities Pjand Qmare investigated. Several explicit formulae for Qmare given. The asymptotic approximations for multiplicities Pjand Qm, which are the Wigner and Gauss distributions respectively, are derived. All parameters of the distributions are explicitly obtained. A comparison of theoretical multiplicities with the exact ones is made when the number of angular moments is relatively small.

关键词： Explicit formula Angle law of large numbers Gauss equation Gauss Moment of force Arbitrary Graham's number Angular momentum asymptotic distributed parameter

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CALCULATION OF THE HEAT-TRANSFER COEFFICIENT FOR FREE LAMINAR CONVECTION ON VERTICAL CYLINDERS USING THE INTEGRAL METHOD

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WARME UND STOFFUBERTRAGUNG-THERMO AND FLUID DYNAMICS 1988年第3-4期22卷 147-150页

作者： SUPPANZ, N 1. Fachbereich Versorgungs- und Energietechnik Luxemburger Str. 10 1000 Berlin 65

Solutions of the momentum and energy boundary-layer equations for heat transfer on vertical cylinders are presented. The velocity and temperature distribution as developed by Eckert have been applied. The parameters of the distributions on the cylinder are related to those of an equivalent wall having corresponding height and similar boundary conditions. With such assumptions the boundary-layer equations can be solved. The Nusselt Number as determined corresponds well with that calculated using numerical methods.

关键词： Cylinders Heat transfer Momentum Boundary conditions distributed parameter speed Equation Temperature distribution Solutions Vertical cylinder Cylinders Numerical methods Nusselt number

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