Abstracts
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Lecture Session 1
L1a: Topic 2:
Matrix Converters
(O. Apeldoorn, ABB, Switzerland, A. Haböck,
Siemens, Germany)
Theory of Vector Modulation for Matrix Converters
Olaf Simon
A&D SD E 6, Siemens AG
Frauenauracher Str. 80
D-91056 Erlangen, Germany
Olaf.Simon@erlf.siemens.de
Michael Braun
Elektrotechnisches Institut, Universitat Karlsruhe
Kaiserstraكe 12
D-76128 Karlsruhe, Germany
Braun@eti.etec.uni-karlsruhe.de
Although space vector modulation techniques for matrix converters have
been introduced already, a
closed theory for describing the possible output voltage and input current for
any modulation scheme
has not been presented yet. This paper contains the derivation of two simple
equations, one for the
output voltage, one for the input current, which are the transfer functions of
the matrix converter. The
complicated control of the matrix converter is reduced to methods known from dc
link converters.
Application of a new IGBT Module for Matrixconverter
M. Bruckmann*, O. Simon, W. Springmann, M. Münzer**, M. Loddenkötter**
A&D SD RD D, Siemens AG
Frauenauracher Str. 80
D-91056 Erlangen, Germany
manfred.bruckmann@erlf.siemens.de
** Eupec GmbH
Max Plank Str. 5
D-59581 Warstein
@eupec.com
For more than twenty years, Matrix topology has been discussed on technical conferences, but up to now only few authors have discussed the realisation of a feasible technical solution for the power section of that type of converter. In this paper, for the first time the application of a new complete all in one IGBT module incorporating the full switch matrix in a powerstage for matrixconverter is presented. Experimental results of a laboratory prototype in regular and critical conditions demonstrate the feasibility of the concept. It is concluded that some of the open questions dealing with reliability and manufacturability can be considered as solved.
Measurement and Simulation of Commutation Phenomena in Direct AC-AC
Converters
Michael Bland, Jon Clare, Patrick Wheeler, Lee Empringham
SCHOOL OF ELECTRICAL AND ELECTRONIC ENGINEERING,
The University of Nottingham,
Nottingham, NG7 2RD, ENGLAND
Tel : +44 115 951 5545 / Fax : +44 115 951 5616
E-mail: mjb@eee.nottingham.ac.uk
http://www.eee.nott.ac.uk/power/
The characteristics of all possible commutations in a matrix converter topology using two or four step commutation are studied and explained. Waveforms obtained from two bi-directional switches commutating current between two input phases are presented and the commutation phenomena are explained. Comparisons between PSPICE circuit simulations of the commutation and practical results are made.
Direct Torque Control using Matrix Converters: Improvement of the Input Line Current Quality.
D.Casadei,M.Matteini,G.Serra,A.Tani
UniversityofBologna
DepartmentofElectricalEngineering
VialeRisorgimento,2
40136Bologna-Italy
Phone+390512093582/Fax+390512093588
e-mail:domenico.casadei@mail.ing.unibo.it
F.Blaabjerg
AalborgUniversity
InstituteofEnergyTechnology
Pontoppidanstraede101,
DK-9220AalborgEast,DENMARK
Phone+4596358080/Fax+4598151411
e-mail:fbl@iet.auc.dk
In this paper a new control method that allows the application of matrix converters in Direct Torque Control (DTC) of induction machines is presented. Thanks to the matrix converter topology, this control method allows, under the constraint of unity input power factor, the generation of the voltage vectors required to implement the direct torque control of induction machines. Despite of the major complexity of the matrix converter structure compared to traditional Voltage Source Inverters (VSI), the proposed control algorithm is simple and robust. The appropriate switching configuration of the matrix converter is selected using a switching table defined on the basis of three hysteresis controllers applied to stator flux, electromagnetic torque and input power factor. Numerical and experimental results are carried out and analysed, showing the feasibility of the proposed drive system. Finally, a modified control strategy for the input power factor that reduces the harmonic content of the input line current is proposed and verified by numerical simulations.
L1b: Topic 6: Industrial
Applications
(J. Niiranen, ABB, Finland, J. Coquery, INRETS,
France)
Conventional 3-phase Power Converters for Magnetic
Bearings
Christian Redemann
LEViTEC GmbH
Gewerbestrasse 5-9
35633 Lahnau, Germany
Tel.: +49(0)6441 966 514 / Fax: +49(0)6441 966 515
christian.redemann@levitec.de
http://www.levitec.de
Peter Jenckel
LEViTEC GmbH
Gewerbestrasse 5-9
35633 Lahnau, Germany
Tel.: +49(0)6441 966 511 / Fax: +49(0)6441 966 515
peter.jenckel@levitec.de
http://www.levitec.de
Conventional active magnetic bearings usually used four unipolar or two
bipolar amplifiers. These types of amplifiers are not produced in high
quantities and are therefore relatively expensive. In this paper some
configurations for magnetic bearing controllers based on 3-phase power
converters and the bearings are presented and shown using some industrial
applications.
Transformerless Drive System for Main Line Rail
Vehicle Propulsion
Sibylle Dieckerhoff, Uwe Schäfer
DaimlerChrysler AG, Research and Technology
Neuendorfstr. 20a, 16761 Hennigsdorf, Germany
++49 3302 8881-54, Fax: ++49 3302 888115
Sibylle.Dieckerhoff@DaimlerChrysler.com
Uwe.U.Schaefer@DaimlerChrysler.com
Low frequency, medium voltage transformers in main line rail vehicles suffer
from poor efficiency and high weight. Completely transformerless solutions were
not up to now attractive due to the high motor and converter expenditures. To
solve these problems, motors with a more medium voltage friendly winding
structure as e.g. an induction motor with fractional slot winding are proposed.
Based on the new 6.5kV IGBT, the feasibility of multilevel converter topologies
as the diode clamped converter and the flying capacitor converter is analysed.
The paper gives an evaluation of drive concepts combining motor and converter
properties. A solution with 4 series connected drives turns out to be the most
favourable solution.
Implementation and Comparison of Three Approaches for
Energy-Optimized Strategies of a Synchronous Machine and its Inverter
R. Trigui, F. Harel, J. Scordia
French National Research Institute on Transportation and Safety.
25 avenue F. Mitterand, case 24 69675 Bron, France.
E-mail : trigui@inrets.fr
Ph. Bastiani, J. M. Rétif, X. Lin-Shi
CEGELY-INSA, Bât L. de Vinci, 21 av. Capelle, 69621 Villeurbanne Cedex, France.
E-mail : retif@cegely.insa-lyon.fr
F. Chabot, E. Gimet, J. Beretta
PSA PEUGEOT CITROËN -Research and Advanced Projects – Electric and Electronic
Systems
2 route de Gisy, 78943 Vélizy-Villacoublay, France.
E-mail: chabot2@mpsa.com
This paper presents an implementation and comparison of three approaches for
an energy-optimized synchronous-drive control. A digital control is carried out
allowing an energy saving with widely sufficient dynamic operation for Electric
and Hybrid Vehicles (E&HV) applications. The experimental results show a good
current controller performance and a considerable efficiency gain compared to a
non optimized control.
Control Strategies of Induction Motor Fed by a Tandem
DC Link Frequency Converter
Maria Imecs, Ioan I. Incze, Csaba Szabó
TECHNICAL UNIVERSITY OF CLUJ-NAPOCA
Department of Electrical Drives and Robots
P.O. 1, Box 99,
RO-3400, Cluj-Napoca, Romania
Phone/Fax: +40 64 194924
imecs@edr.utcluj.ro,
ioan.incze@edr.utcluj.ro,
csaba.szabo@edr.utcluj.ro
The paper deals with vector control structures for the “tandem” frequency converter fed induction motor drives. This type of converter is composed of an amplitude-modulated current-source inverter and a PWM voltage-source one connected in parallel arrangement. In tandem operation mode the two converters require synchronization in time and in the magnitude of the currents in order to avoid energy circulation between them, otherwise the low power range PWM inverter will be uncontrolled overloaded. In comparison with an equivalent PWM converter in tandem running of the two component ones the switching losses will be smaller because the most part of the energy is transferred without modulation. Due to the voltage-source behaviour of the tandem converter it needs special control structures, where the PWM inverter will have the role of the motor actuator. Rotor-field-oriented vector control methods using “bang-bang” current-feedback modulation and voltage feedforward PWM are presented, and compared with stator-field-oriented vector control suitable only for proper stator-voltage control. Performance problems of the different control schemes related to PWM methods, control variable computation and orientation-field identification are outlined. Three characteristic control structures for induction motor drive systems were simulated using MATLAB-Simulink-environment.
L1c: Topic 9: Power electronics and
drives in the automotive industry
(R. Kennel, Bergische
Universitaet, Wuppertal, Germany, A. Vezzini, Biel School of
Technology and Architecture, Switzerland)
Modelling and Control of a Flywheel Powered Ultra
Light Rail Bus
J. Wang
Department of Electronic and Electrical Engineering, University of Sheffield
Mappin Street, Sheffield S1 3JD, United Kingdom
Tel: + 44114 22 25817, Fax: +44114 22 25196
Email: j.b.wang@shef.ac.uk
R. Perryman
School of Electrical & Manufacturing Engineering, University of East London
4 University Way, Docklands, London E16 2RD, United Kingdom
Tel: +4420 8223 2365, Fax: +4420 223 2847
Email: r.perryman@uel.ac.uk
This paper describes the modelling and control system design of an integrated electric drive train for a flywheel powered ultra light rail bus. The vehicle is developed to provide an alternative means of transportation for an inner city area in order to reduce air pollution and traffic congestion. Brushless permanent magnet machine drive technology is chosen to maximise energy and volumetric efficiencies of the drive train. The modelling of key elements and their interaction in the system are highlighted. A co-ordinated control strategy to regulate the power flow balance is proposed, and its design detail presented. The validity and effectiveness of the control and design methodology have been confirmed by computer simulation and will be demonstrated on a prototype vehicle.
Power scheduling of the Emafer high-speed flywheel
using coupled voltage source inverters.
H. Huisman - E.J.F.M. Smits.
Centre for Construction and Mechatronics (CCM),
De Pinckart 24
5674 CC Nuenen
The Netherlands
Phone: +31402635000
Fax: +31402635555
e-mail: henk.huisman@ccm.nl
A flywheel unit with integrated motor-generator is used as an energy buffer
and power booster for a light-rail vehicle. Severe demands are placed on the
quality of the motor-generator currents. The use of a pair of paralleled voltage
source inverters (VSI’s) allows to obtain a double effective switching frequency.
Measured results are shown to confirm the operation of the system.
Multiplexing automotive component solutions
Philippe Mounier
MOTOROLA Semiconductors
Le Mirail, BP1029
31023 Toulouse, France
Tel (33) 561199354 – Fax (33) 561199957
philippe.mounier@Motorola.com
Presented by Francoise Vareilhias
Multiplexing systems are now in every car. Each single application is connected
to one or more vehicle network. The so-called "physical layer" is now part of
semiconductor supplier catalogue either as standard component or as functional
block in library used in new ASIC design or custom circuit. With future system
partitioning where is the optimum location of the interface? What are the
evolutions of the physical layer requirements? These are some of the questions
this paper will address.
Torque linearity for high speed drives with a wide
field weakening range
Dr. Dominik Hofmeyer
ALSTOM Power Conversion GmbH
Culemeyerstr. 1
D-12277 Berlin, Germany
phone.: +49 30 7496 2384 fax.: +49 30 7496 2303
dominik.hofmeyer@powerconv.alstom.com
Industrial torque controlled drives with enhanced torque linearity demands
require the compensation of saturation, iron losses and rotor resistance
estimation. The application of a very simple rotor time constant estimator is
presented, which is advantageous related to the required hardware and
implementation effort. Necessary conditions for correct estimation and their
practical realisation are discussed. Practical results with several test bench
machines are presented.
L1d: Topic 10: Generation and
renewable energy
(M. Crappe, F. P. Ms, Belgium, W. Koczara, T.U.
of Warsaw, Poland)
Multi-String-Converter: The next
step in evolution of String-Converter Technology
Mike Meinhardt, Günther Cramer
SMA Regelsysteme GmbH,
Hannoversche Straكe 1-5,
D-34266 Niestetal, Germany,
Phone: +49 561 9522-0 Fax: +49 561 9522-100,
Email: meinhardt@sma.de
http://www.sma.de
The development of a PV-converter based on the advanced Multi-String concept
results in significantly reduced specific costs while still profiting from the
well-known advantages of the String-converter technology developed by ISET and
SMA in the mid-nineties. The paper deals with the basic considerations from a
system’s point of view that resulted in the development of the
Multi-String-converter. The features of the Multi-String-Converter concerning
operational behaviour and PV-system design are described. Due to enhanced
capacity of the operational control unit the Multi-String-converter can be used
additionally for active compensation of harmonics and reactive power in order to
improve the power quality. An evaluation of Multi-String-converters in
comparison with String-converters or conventional Central-converter concepts is
presented. The selected topology and the control strategy for the
Multi-String-converter are introduced.
Rotor-Controlled Generator Systems For Wind Energy
Applications
Hermann-Josef Conraths
Siemens AG
P. O. Box 47 43
D-90025 Nürnberg,
Germany
Phone: +49 911 433 6441
Fax: +49 911 433 9751
email:
hermann-josef.conraths@nbg7.siemens.de
In the last two decades renewable energy systems have become of major
interest all over the world. Besides the well established generation of
electrical energy by hydropower, wind energy systems have proved to be a
technical and economical alternative to the conventional thermal power stations.
Different concepts of wind turbine systems are on the market, which differ not
only in total power and mechanical design, but also in the way the mechanical
energy of the rotating turbine is converted to electricity. The increasing power
of the wind converters and their integration into wind parks demands for a
higher control level, for an efficient control of the speed as well as the
active and reactive power of the generator. In the present paper the
asynchronous slipring generator with inverter control in the rotor circuit is
presented in detail. The major characteristics of the system are discussed.
Tool for Evaluation of Configuration of Offshore
Windparks: Models of the Components
P. Bauer*, S.W.H.de Haan*, M.E.C.Damen*,
J.T.G.Pierik+
* Delft University of Technology
Mekelweg 4
2628CD Delft The Netherlands
+ Netherlands Energy Research Foundation
A tool for Evaluation of Configuration of Offshore Windparks is suggested and
models of the components studied. Several methods to collect the power can be
distinguished and the designer has to evaluate the technical and economical
properties of several different configurations. The transmission of the electric
power to shore and concepts for the electrical system of offshore wind farms are
evaluated with respect to costs due to losses, and energy yield. Both string and
star cluster formation and the different types of coupling of variable and
constant speed generators are considered. The interest lies primarily in
identifying farm configurations with a low cost profile and high efficiency.
Case study for a 500MW park for two different locations is presented.
Variable Speed Three Phase Power
Generation Set
Wold Koczara*, Jaroslaw Leonarski*, Robert Dziuba*,
Nazar Al-Khayat+, Nigel Jakeman+
* Technical University of Warsaw, Warsaw Poland
+ Newage International, Barnack Rd, Stamford, England
This paper is focused on the industrial development of a novel type variable
speed power generating system that can be used for the supply of electrical
loads in the range 10kVA to 100kVA. Variable-Speed-Integrated-Generating (VSIG)
sets consist of a diesel engine, an axial type permanent magnet generator and
high frequency power converter that is IGBT based. The axial type PMG has proved
to be the best candidate for variable speed application. The power to weight
ratio of the set is significantly more than traditional sets incorporating a
wound field synchronous generator. Mechanical integration of the generator and
engine must consider torque pulsation and axial thrust. The unique feature of
the control system is the control algorithm which ensures fast response of the
system to load application and accurate mapping of engine torque with load
current.
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Lecture Session 2
L2a: Topic 2:
Multilevel Converters
(T. Meynard, LEEI-ENSEEIHT. France, Dushan Borojewic, Virginia Polytechnic Inst. USA)
A
Generalized Design Principle of a Uniform Step
Asymmetrical Multilevel Converter For High Power Conversion
J. Song-Manguelle, S. Mariethoz, M. Veenstra and Prof. A. Rufer
Swiss Federal Institute of Technology, Lausanne
Industrial Electronics Laboratory, CH-1015 Lausanne, Switzerland
Phone : +4121 6934789 / Fax : +4121 6932600
http://leiwww.epfl.ch
This paper is focused on a general design principle of a uniform step multilevel
converter, with K series-connected full bridges inverters per phase. A new
design terminology is proposed and analytical relationships are established. The
DC-voltage sources supplying partial inverters are supposed to be rationally
unbalanced. The corresponding symmetrical topology provides more flexibility to
the designer, and can generate a large number of levels (any odd number from
2K+1 to 3K) without increasing the number of H-bridges. Simulation results and
experimental tests shown the reliability of the design approach suggested.
Stacked Multicell Converter (SMC):
Topology and control
G. Gateau, T.A. Meynard, H. Foch
Laboratoire d’Electrotechnique et d’Electronique Industrielle
Unité Mixte Recherche I.N.P.T.-E.N.S.E.E.I.H.T. / C.N.R.S. 5828
BP 7122 - 2, rue Camichel, 31071 Toulouse Cedex 7 - France
Fax: (33) 5 61 63 88 75 -
E-mail : leei@leei.enseeiht.fr
A new topology of multilevel converter is presented in this paper. This new topology called Stacked Multicell Converter (SMC) allows to increase the number of voltage levels compared with the standard flying capacitor multicell converter while decreasing the energy stored in the converter. The topology consists of a hybrid association of commutation cells allowing to share the bus voltage over several switches, and also to improve significantly the output waveforms of the converter (increased number of levels and increased apparent switching frequency). The topology, the corresponding modulator and the basic operation are detailed. In a third part, explanations about the control of the SMC converter are given. Simulations and experimental results obtained on a 50kVA experimental set-up are presented.
A new range of medium voltage multilevel
inverter drives with floating capacitor technology
Georg Beinhold, Roland Jakob, Manfred Nahrstaedt
Alstom Power Conversion GmbH
Culemeyerstrasse 1
D-12277 Berlin, Germany
phone: +49(0)30 7496 2394/ 2393/ 2306
e-mail:
georg.beinhold@powerconv.alstom.com
e-mail:
roland.jakob@powerconv.alstom.com
e-mail:
manfred.nahrstaedt@powerconv.alstom.com
http://www.alstom.com
An air cooled medium voltage drive family called “SYMPHONY” based on IGBT
modules and floating capacitor topology is described. The harmonic content of
both, input and output current is very low, due to 18 pulse input and 4-level
voltage output. Beside principal explanations to introduce the solution, the
clearly arranged design is described, leading to high reliability, because of a
low number of components and low cost of maintenance. A closer look is given to
the key components like “partial discharge free low inductance bus bars”,
“gating power supply” and the “floating capacitor module”
Topology and Balance Control of Medium
Voltage Multilevel Drives
Christian Keller, Roland Jakob
Alstom Power Conversion GmbH
Culemeyerstrasse 1
D-12277 Berlin, Germany
phone: +49(0)30 7496 2382
e-mail:
christian.keller@powerconv.alstom.com
e-mail:
roland.jakob@powerconv.alstom.com
http://www.alstom.com
Samir Salama
University of Applied Sciences
Josef-Gockeln-Strasse 9
D-40474 Düsseldorf, Germany
phone: +49(0)211 4351 314
e-mail:
samir.salama@fh-duesseldorf.de
The paper presents a new reliable series connection technique of power
semiconductor devices using the floating capacitor multilevel topology. For
improved dynamic voltage sharing of the series connected devices floating
capacitors with much smaller capacitance values are used than those used by the
standard floating capacitor topology. A simple voltage sharing control strategy
which does not need neither high dynamic voltage measuring devices nor fast
signal signal processing will be presented.
Theoretical and Practical Limits in Multilevel MPC Inverters with Passive Front Ends
Mario MarchesoniUniversità di Genova
Dipartimento Ingegneria Elettrica Via all’Opera Pia 11a
16145 Genova-Italy
Tel: +39-010-3532183
Fax: +39-010-3532700
marchesoni@die.unige.it
Pierluigi Tenca
IEEE Member
Judengasse 10 EG
91058 Erlangen Germany
tenca@die.unige.it
DC-link capacitor voltages in Multi-Point-Clamped (MPC) converters must be actively controlled to achieve a correct voltage sharing. This works demonstrates that no balancing strategy does exist that is able to guarantee a correct functioning in all the operating conditions, if single MPC inverters or rectifiers are considered. The analytical work that has been done to determine the theoretical limits related to a correct converter behaviour is presented. In addition, a balancing control strategy that has been based on the developed theory is described and a lot of almost theoretical and practical results are presented.
Characteristics of a Five-Level Double
Converter for Induction Motor Drive
Takashi Ishida*, Tetsuya Miyamoto*, Kouki Matsuse*,
Kiyoaki Sasagawa**, and Lipei Huang***
*Dept. of Electrical and Electronic Engineering, Meiji University
Higashi-mita, Tama-ku, Kawasaki 214-8571, Japan
Phone / Fax: +81-44-934-7293, E-mail:
matsuse@isc.meiji.ac.jp
**Fuji Electric Corporate Research and Development, Ltd.
1, Fujimachi, Hino 191-8502, Japan
***Dept. of Electrical Engineering, Tsinghua University
Beijing 100084, China
In this paper, two kinds of control strategies for a three-phase five-level
double converter are described on the assumption that the converter is applied
to the induction motor drive system. The purposes of the proposed control
strategies are to correct voltage imbalance of the dc-bus capacitors, to keep
the input power factor at near unity, and to achieve adjustable-speed drive.
Characteristics of the converter operated by each of the two control strategies
are examined and the validity is verified by experiments using a 3.7 kW
induction motor.
L2b: Topic 6:
Sensorless Induction motor drives
(M. Schroedl T. U. Wien,
Austria, B. de Fornel, ENSEEIHT, France
Sensorless Field
Oriented Control of Induction Motors Using Test Signals
to Ensure Stable Operation at Very Low Stator
Frequencies
C. Rudolph, U. Schümann, B. Orlik
University of Bremen
Institute for Electrical Drives, Power Electronics and Electrical Devices
Kufsteiner Strasse, NW1
28359 Bremen, Germany
Tel.: (+49) 421-218-2054, Fax.: (+49) 421-218-4318
e-mail:
christian.rudolph@uni-bremen.de
uschuem@et.uni-bremen.de
The sensorless field oriented control of induction motor drives requires the calculation of the flux angle and the speed by a model from stator voltages and currents. A new method is described to identify the flux angle even down to zero Hertz stator frequency, thus stable operation of the sensorless controlled drive is ensured in the entire torque-speed plane. If model parameters deviate from machine parameters the quality of the control deteriorates. Therefore the machine parameters have to be identified accurately before starting the control. During operation the sensorless control can be improved by an online adaptation of the stator and the rotor resistance using a thermal observer.
Improving the Dynamic Performance of
Carrier Signal Injection Based Sensorless AC Drives
F. Briz, M.W. Degner†, J.M. Guerrero, A. Diez
Dept. of Electrical, Computer and Systems Engineering
University of Oviedo 2101
Gijon 33204, Spain,
Tel: 348-518-2289 Fax: 348-518-2068
email: fernando@isa.uniovi.es
†Ford Motor Company
Ford Research Laboratory
Village Road, P.O. Box 2053, MD 1170
Dearborn, MI 48121, USA
Tel: 313-322-6499
Fax: 313-323-8239
email: mdegner@ford.com
This paper analyzes the problems caused by the interaction between the fundamental current and the carrier signal current in carrier signal injection based sensorless AC drives. This interaction can be caused by a lack of spectral separation between the two signals during steady-state operation or by transients in the fundamental current. Both of these phenomena are first analyzed and then a solution based on dynamic decoupling using a fundamental current observer is proposed.
A High Performance Sensorless Induction
Motor Drive for use in Multi-Motor Speed Synchronised Applications
G. Turl, M. Sumner and G. M. Asher
School of Electrical and Electronic Engineering
The University of Nottingham, University Park
Nottingham NG7 2RD, UK
Tel: +44 (0) 115 9515549
Fax: +44 (0) 115 9515616
Email: gt@eee.nottingham.ac.uk
http://www.eee.nottingham.ac.uk/power/
This paper presents a high performance sensorless induction motor drive that
is based on the machine electrical model and tuned by a robust speed estimate.
This estimate is obtained from an adaptive algorithm tracking rotor slot
harmonics that appear in voltage and current quantities. The resultant system is
tested for use in multi-motor, speed synchronised drives, an application
typically requiring encodered performance. Excellent system performance is
demonstrated on a dual 4kW experimental rig.
ImproVed Control of induction motor
drives Without a Shaft Sensor
Gerd Terörde and Ronnie Belmans
Katholieke Universiteit Leuven, E.E. Dept., Div. ESAT/ELEN
Kasteelpark Arenberg 10, B-3001 Leuven-Heverlee, Belgium.
Phone (+)32-16-32 10 20
Fax (+)32-16-32 19 85
e-mail:
gerd.teroerde@esat.kuleuven.ac.be
www.esat.kuleuven.ac.be/elen/
Induction motors are relatively cheap and rugged machines. Only a closed loop
control of the motor meets the requirements including fast dynamic response,
accurate speed and torque control or even a higher efficiency by means of flux
optimization. However, the speed sensor has several disadvantages from the
viewpoint of drive cost, reliability and signal noise immunity. This paper deals
with the speed control of induction motor drives without a shaft sensor. Here, a
new model for speed estimation is proposed. Its structure is based on the
Extended Kalman Filter theory. A 1,5 kW induction motor experimental system has
been built to verify this approach. Experimental results are presented to
demonstrate the performance of the system.
An Artificial Neural Network for Stator
Resistance Estimation in a Sensorless Vector Controlled Induction Motor Drive
James Campbell and Mark Sumner
School of Electrical and Electronic Engineering
University of Nottingham
Nottingham NG7 2RD, UK
Tel 0115 9515549
Fax 0115 9515616
This paper describes a novel high performance sensorless vector controlled
induction motor drive. Sensorless speed control is achieved using a Model
Reference Adaptive System which employs a Closed Loop Flux Observer for field
orientation. To improve low speed operation the system uses an Artificial Neural
Network to estimate changes in the stator resistance. This ensures correct
orientation and speed estimation, with distinct improvements to drive stability,
especially when the resistive voltage drops become significant at lower speeds.
Experimental results are presented to verify this.
Encoderless Position Control of
Induction Machines
Nikolas Teske, Greg M. Asher, Mark Sumner, and Keith J. Bradley
School of Electrical and Electronic Engineering,
The University of Nottingham,
Nottingham, NG7 2RD, ENGLAND
Tel : +44 115 951 5545, Fax : +44 115 951 5616
Email: greg.asher@nottingham.ac.uk
http://www.eee.nott.ac.uk/power/
This paper presents advances in sensorless position control of induction
machines using a standard or ‘sym-metric’ rotor. The rotor position information
is obtained by high frequency voltage injection and using the modulating effect
of the rotor slots. This makes true sensorless control possible, including zero
speed. The deteriorating effect of saturation-induced saliencies at full ux and
higher loads is suppressed by using a new harmonic compensation scheme which we
term Space-Modulation Profiling (SMP). This method also reduces the unwanted
modulation of the high frequency voltage at the instance of a fundamental
current crossing through zero due to inverter deadtime.
This paper analyzes the distorting modulation due to saturation and current
zero-crossing and shows the decoupling of the position harmonics via SMP as a
solution to enhance the position estimation accuracy. Results are presented,
showing true sensorless position control at full ux and under high load which
has not been published before.
L2c: Topic 8:
Measurement and sensors
(J.A. (Braham) Ferreira, T.U. Delft, The
Netherlands, S. Tenconi, Ansaldo Ricerche, Italy)
An observer to improve the speed signal using
a Ferraris acceleration sensor
Jochen Fastnacht, Peter Mutschler
Department of Power Electronic and Control of Drives
Darmstadt University of Technology
Landgraf-Georg-Str. 4
D-64283 Darmstadt, Germany
Phone: 49 6151 162666 / Fax: 49 6151 162613
jfass@srt.tu-darmstadt.de
http://www.srt.tu-darmstadt.de
In high precision machining and high dynamic control the availability of an
accurate speed signal is of increasing importance. This paper presents the use
of a state observer to improve the speed signal for servo drives with the help
of a commercial acceleration sensor. Methods to improve the acceleration signal
with the help of the incremental encoder signal are also described. The measured
results and the appropriate conclusions will show the possible performance, the
advantages and disadvantages of such a system. The active damping of high
frequent mechanical oscillations is shown in the paper which evidences the
performance of the observer solution.
Precision Low Cost Electric Motor Flux and Torque Measurement Method
F. Giulii Capponi, A.
Stabile
Dept. of Electrical Engineering
Univ. of Rome “La Sapienza”
V. Eudossiana, 18
00184 Rome (ITALY)
ph: +39-06-44585308
fax: +39-06-4883235
giulii@elettrica.ing.uniroma1.it
A. Di Napoli
Dept. of Mech. & Indust. Eng.
University of “Roma TRE”
V. della Vasca Navale, 79, 00146 Rome (ITALY)
ph: +39-06-55173283
fax: +39-06-5593732
dinapoli@uniroma3.it
A. Violi
Trenitalia S.p.A. - UTMR
Direzione Tecnica - Sperimentazione -
Prove Elettriche
V. le S. Lavagnini, 58
50129 Firenze (ITALY)
masini@asamrt.interbusiness.it
Torque and flux measurements in ac motor
are often a complicated matter.
For flux measurement, a coil or a field sensor must be inserted inside stator
windings causing relevant costs especially for big machines. Anyway, measurement
has not great accuracy since calibration is not easy. For torque measurement, a
telemetry system can be installed on rotor axle but, especially for notable
accuracy, this system has high costs. Sometimes is not possible to install a
telemetry directly on rotor axle and a gear box must be interposed, losing every
chance to obtain a precise measurement. Cost and measurement uncertainties
increase with machine size so that, for high power (more than 500 kW), this is
about an insoluble matter.
In this paper, a method based on a state observer is proposed, that overcomes
all disadvantages of other methods because only voltages and current measurement
is needed. For more accuracy, only rotor speed measurement is needed in addition.
Design of a Real-Time Load Simulator
Based on an In-Parallel Connected PWM Voltage Source Converter Structure
S. Trabelsi*, W. Schumacher* and A. Tolksdorf**
* Technische Universität Braunschweig, Institut für Regelungstechnik,
Hans-Sommer-Str 66, D-38106 Braunschweig, Germany
Tel: +49-531-3913846 Fax: +49-531-391-5194
Email: sami.trabelsi@tu-bs.de
www.ifr.ing.tu-bs.de
** Lenze GmbH & Co KG, Groß Berkel,
Hans-Lenze-Straße 1, D-31855 Aerzen, Germany
Tel: +49-5154-822550 Fax: +49-5154-822616
In the end of a production line a new built power converter has to undergo a
series of stress tests. This can be achieved by connecting it to a dynamometer
consisting of a three-phase machine joined by a rigid shaft to a DC load machine.
The latter is controlled to create some specific load characteristic needed for
the test. In this paper a test method is proposed, in which no mechanical
equipment is needed. The suggested test stand consists only of a converter to be
tested and a simulator converter. Both devices are connected back-to-back on the
AC-side via smoothing reactors. The simulator operates in real-time as an
equivalent load circuit, so that the device under test will only notice the
behaviour of a three-phase machine under consideration of the load.
A Single-Sensor Principle for Power
Converters
Dongyuan Qiu, S.Y.(Ron) Hui and Henry Chung
Department of Electronic Engineering
City University of Hong Kong
Tat Chee Aveune, Kowloon
Hong Kong, China
Tel: (852) 2788 9853 Fax: (852) 2788 7791
Email: eeronhui@cityu.edu.hk
A simple and effective single-sensor estimation method is described in this
paper. Using only one sensor, the proposed method can provide all necessary
information for feedfoward and feedback control and parameter estimation. The
principle is demonstrated in a commonly used half-bridge converter under
high-frequency operation. The input voltage, load resistance, load voltage and
output power are estimated in this example. It is found that the proposed method
can estimate these variables and parameters with high degree of accuracy. The
method can reduce the number of sensors and eliminate the requirement of complex
isolated feedback circuitry in power converters.
DSP Controlled Automated Test Bench for
Linear Actuators - Design and Choices
P. Germano, Ch. Kuert, M. Jufer.
Swiss Federal Institute of Technology, Lausanne (EPFL) / DE-LEME
ELG Ecublens
1015 Lausanne, Switzerland
Tel: +41 21 693 48 58 - Fax: +41 21 693 26 87
Paolo.Germano@epfl.ch
Christoph.Kuert@epfl.ch
Marcel.Jufer@epfl.ch
http://lemewww.epfl.ch/
Linear motion is interesting in various applications fields such as automotive,
medical or heating/ventilation/air conditioning. Linear actuators are used for
flow rate regulation purposes. Knowing their characteristics and analysing their
behaviour are important to improve the performances. An original DSP controlled
automatic test bench has been designed and developed to characterise linear
actuators, with low manual handling and enhanced measurement accuracy.
The mechanical elements of the test bench consist in a load part and a test part
coupled through a spring. A force sensor is placed between the load part and the
spring. A linear optical encoder, fixed on the test part, directly measures the
position of the test part. The measurement process takes place in two phases:
first, the stress is applied on the actuator using the feed-back loop (DSP 1 in
"force regulation" mode). Secondly, the actuator is started through the "DSP 2
frequency generator". The load part position is controlled according to the
actuator position (DSP 1 in "position follower" mode). The absolute position and
the force signals are acquired during displacement cycle.
The 2 main measurement processes are based on a dichotomous method. To reach the
maximal force of the actuator, the load is increased or decreased depending on
the result of the previous measurement.
The test bench is able to draw the following characteristic curves: force vs.
current, force vs. speed, backlash/precision/stiffness/hysteresis vs. position
and reverse force.
Speed Measurement Method for Digital
Control System
Stefan Brock, Krzysztof Zawirski
POZNAN UNIVERSITY OF TECHNOLOGY
ul. Piotrowo 3A, 60-965 Poznan
Poland
Fax: (+ 48 61) 6652389
E-mail: Stefan.Brock@put.poznan.pl
E-mail: Krzysztof.Zawirski@put.poznan.pl
In the paper a modified digital speed measurement method is proposed. The
method has a good static accuracy, like well known other measurement procedures,
but its advantage consists in a constant sampling period. The method is
implemented on single chip microcontroller. Experimental results proved good
properties of the proposed concept.
L2d: Topic 10: Power
electronics in the grid (FACTS)
(R. Belmans, KULeuven, Belgium,
A. Haböck, Siemens, Germany)
Elimination of Low Order Harmonics in a
Three-Level InverterUsed for Static VAr Compensation
Li Ran Lee Holdsworth Ghanim Putrus
School of Engineering, University of Northumbria
Ellison Building
Newcastle upon Tyne, NE1 8ST, UK
Telephone: 0044 (0)191 2274902
Fax: 0044 (0)191 2273684
e-mail: li.ran@unn.ac.uk
This paper is concerned with the harmonic absorption of DC side capacitors in
a 3-level inverter operated as an ASVC. The effects of the load level and the
switching pattern are analysed. It is shown that the DC voltage ripple will
affect the AC side harmonic spectrum. Requirements to eliminate the dominant 3rd
harmonic absorption are identified. A switching strategy to control the DC side
harmonics and an expanded system configuration are investigated. A new dynamic
selective harmonic elimination modulation method (SHEM) is described to improve
the inverter output voltage; the switching angles to track the operating point
are derived. The analysis is illustrated using simulation and experiment.
Fast acting solid-state circuit breaker using state-of-the-art power-electronic devices
L. Klingbeil, W. Kalkner
University of Technology Berlin, Faculty IV
Institute for Power Engineering and Automation,
Dept. of High Voltage Engineering
Einsteinufer 11, HT 3
D-10587 Berlin, Germany
Tel.: +49-30-314-23394
Fax.: +49-30-314-21142
e-mail:
Klingbeil@ihs.ee.tu-berlin.de
http://ihs.ee.tu-berlin.de
Ch. Heinrich
Siemens AG
Power Transmission and Distribution
Medium Voltage
Carl-Benz-Str. 22,
D-60386 Frankfurt am Main, Germany
Tel.: +49-69-4008-2363
Fax.: +49-69-4008-2523
e-mail:
christian.heinrich@ffm7.siemens.de
Recent advancement in power semiconductors has been remarkable and the use of
power semiconductor devices in applications for distribution of electrical
energy has become an important field of research.
The paper describes investigations on modern power-semiconductors for use in
fast-acting circuit breakers. Aim of the investigations is a comparison of
different types of solid-state switching devices as well as the proof of their
eligibility for use in medium-voltage distribution systems. Laboratory tests
were made to show the switching behaviour at high currents. Simulations were
done to compare the experimental results with the simulation models and to
predict the operation behaviour in networks.
Design and control of
a current-controlled Current Limiting Device
Å. Ekström, P. Bennich, M. De Oliveira and A. Wikström
Dept of Electric Power Systems, Inst of Electrotechnical Systems,
Royal Institute of Technology,
S-100 44 Stockholm, Sweden
peterb@ekc.kth.se
With the increasing demands on the power quality as experienced by sensitive
customers, the interest for so called Custom Power devices has increased
significantly during recent years. This contribution presents the design and
control of a pure semiconductor based Current Limiting Device (CLD), which can
be controlled not only to limit but also actively control fault currents in
order to reduce the influence of faults in distribution networks.
Developments
in modelling and analysis of HVDC control systems
M. Aten, K.M. Abbott
ALSTOM T&D, PES
PO BOX 27 PO Box 88,
Stafford, ST17 4LN, England M60 1QD, Manchester, England
Tel : +44(0)1785 257111
Fax : +44(0)1785 252540
Email : martin.aten@tde.alstom.com
N. Jenkins
UMIST, Electrical Engineering Dept
PO Box 88
M60 1QD, Manchester,
England
System Design of Three Phase Active
Filters using Time Domain techniques
Srinivas Ponnaluri
ABB Corporate Research
Speyerer Strasse 4
69115 Heidelberg, Germany
Tel/Fax. +49 6221 596441 / 596353
srinivas.ponnaluri@de.abb.com
http://www.abb.com/decrc
Axel Brickwedde
ABB Corporate Research
Speyerer Strasse 4
69115 Heidelberg, Germany
Tel/Fax. +49 6221 596441 / 596353
axel.brickwedde@de.abb.com
http://www.abb.com/decrc
A new way for designing and analyzing the
Active Filters based on voltage source converters is presented. A systematic step by step design procedure
is explained covering almost entire electrical system design of Active
Filter. This method not only enables a completely
new design of a system but can also be used to analyze an existing system to
find its suitability for a given load.
As the proposed technique is based on time domain it can be implemented
online in the control processor to analyze & monitor
various. For example the junction temperature of the
devices can be calculated online to decide the current limits of converter
thereby making it possible to operate the converter at its maximum capability
at all times. Even though voltage source converters are considered in this paper, it can be
equally applied to current source inverter based systems. MATLAB was used for developing the design
program. This offline program executes
in less than a second on a Pentium Computer.
The program takes basic parameters like load current waveform, supply
voltage waveform, percentage ripple current & voltage etc as inputs and
produces the specifications of various components as output. An online implementation has been done on
the Active Filter Controller and the additional computational time required was
only a small fraction of the control code of the Active Filter. Being
generalized in nature the approach can be used for designing other systems like
UPS.
Voltage Sourced Converter for HVDC
Application
Schwegmann, M.; Kamp P. G.; Weis, B.
Siemens AG, A&D LD IE
Vogelweiherstr. 1-15
D-90441 Nuremberg, Germany
Phone +49/911-433 6315
Fax +49/911-433 7363
e-mail: peter.kamp@nbg7.siemens.de
A new Voltage Sourced Converter (VSC) based system for High Voltage Direct
Current transmission (HVDC) and Flexible AC Transmission Systems (FACTS)
applications with a power rating of more than 200 MW and a DC-Link voltage up to
± 150 kV has been developed. The design of the system and the converters are
discussed. Special attention is also paid to the failure modes and the series
connection of Press Pack IGBT.
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