M. Breil, J-L . Sanchez, P. Austin, J-P. Laur, J. Jalade
LAAS-CNRS
7 avenue du Colonel Roche
31077 Toulouse cédex 4, France
Tel : 33 5 61 33 78 23 / Fax : 33 5 61 33 62 08
e-mail : breil@laas.fr

R. Pezzani, F. Duclos, M. Roy
ST Microelectronics,
16 rue Pierre et Marie Curie,
37071 Tours cédex 2, France

In this paper, two MOS-thyristor associations are investigated, optimized and designed to provide a di/dt active control capability required in specific applications. These devices combine the IGBT and thyristor behaviors, and allow to achieve a new power function, called IGTH. More precisely, these devices switch on in IGBT mode and have a fully latched low on-state voltage. The influence of the physical and technological parameters on the operation modes and on the main electrical characteristics has been analyzed using 2D numerical simulations, analytical calculations and circuit simulations based on specific physical models. Thus, each of these two integrated devices has been specifically designed for a light dimming application, which requires soft switching conditions in order to avoid EMI. Experimental results on a first fabricated test device are presented.

Improved power chip electrical connection

Benoit BOURSAT, Fabrice BREIT, Michel MERMET-GUYENNET
ALSTOM Transport
Rue du Docteur Guinier
BP4 – 65600 Séméac – France
Phone: +33 (0) 5 62 53 44 52 fax: +33 (0) 5 62 53 46 97
E-Mail: benoit.boursat@transport.alstom.com

A new chip connection technique is developed to increase hybrid power module reliability. It is well known that wire bonding is an important failure cause. This paper describes how to realise the chip connections using solder balls, called bumps. And this new technique gives a large flexibility for new packaging design.

Power Factor Correction IPM

Mamoru Seo, Mitsutaka Iwasaki, Hideo Iwamoto
Mitsubishi Electric Corp. Japan

Marco Honsberg
Mitsubishi Electric Europe B.V., Ratingen, Germany
Correspondence address: M. Honsberg,
Mitsubishi Electric Europe B.V.,
Gothaer Strasse 8, 40880 Ratingen, Germany
Tel.: +49 2102 486 9268 (direct)
Fax: + 49 2102 486 722

Against the background of rising global environmental conservation the efforts to save energy by increasing power distribution efficiency and by reduction of power supply harmonic distortion have been assisted by the rapidly progressing development of semiconductors. An Power Factor Correction Intelligent Power Module (PFC-IPM) addresses the problems of both efficiency and power supply harmonic reduction, utilizing PAM (Pulse Amplitude Modulation) to meet the demands of the air conditioner market. The small size / low loss PFC-IPM using boost converter topology provides a high power factor and high efficiency by utilizing the latest Trench Gate IGBT technology is our approach to provide a compact and reliable solution to the white goods market.

Dynamic Electro-Thermal Compact Model of the power Diode Dedicated to Circuit Simulation

P.M. Igic, P.A. Mawby and M.S. Towers
UNIVERSITY OF WALES SWANSEA
Singleton Park
Swansea, United Kingdom
Tel: + 44 1792 295 066 / Fax: + 44 1792 295 686
p.igic@swan.ac.uk

Physically based compact device model of the PiN diode is presented in this paper. For describing correctly static and dynamic behavior of the power diode a new 1-D module for the drift zone (low doped n-base region) is presented which incorporates conductivity modulation and non-quasistatic charge storage effect. Finally, we transformed relatively easy this electric model into the electro-thermal model by adding an extra node (thermal node) to the electrical compact model. This thermal node will store information about junction temperature of the active device and it represents a connection between the device and rest of the circuit thermal network.

Design criteria of high voltage superjunction merged PiN Schottky diode

Antonio G.M.Strollo, Ettore Napoli, Davide De Caro
Dept. of Electronic and Telecom. Eng.
University of Naples "Federico II",
via Claudio, 21
80125 Naples, ITALY
Tel:+39-081-7683124, Fax:+39-081-5934448,
astrollo@unina.it
etnapoli@unina.it
dadecaro@unina.it
www.die.unina.it/GE/

The paper presents a two-dimensional analytical model of superjunction (SJ) devices, giving closed form expression for breakdown voltage.
The model is applied to SJ merged PiN Schottky diodes (SJ-MPS) to minimize on-state resistance for a given breakdown voltage. Performances of optimized SJ-MPS devices with voltage rating ranging from 600V to 1.6kV, are analyzed with bidimensional numerical simulations and compared to standard PiN, MPS, and Schottky diodes.

A new SPICE model of VDMOS transistors including thermal and quasi-saturation effects

V.d’Alessandro and N. Rinaldi
Department of Electronics and Telecommunications Engineering
University of Naples “Federico II”
Via Claudio 21
80125, Naples, Italy
Tel.: +39 (0)81 7683517 / Fax: +39 (0)81 5934448
email: nirinald@unina.it

F.Frisina
ST Microelectronics
Stradale Primosole 50
95121, Catania, Italy
Tel.: +39 (0)95 7407381 / Fax: +39 (0)95 7407099

Keywords: Modelling, MOS device, Thermal design

This paper presents a new electro-thermal analytical model of VDMOS transistors based on the combination of the Level 3 SPICE model for the intrinsic MOSFET and a simple expression for the drift resistance. It is shown that, despite its simplicity, the model provides a good prediction of the device behaviour in all operating modes over the temperature range [300K-400K], describing static device characteristics also in quasi-saturation conditions. Moreover, this model requires a simple parameter extraction procedure and is suitable to be implemented in the circuit simulator SPICE.

Improvement of the Parallel Behavior of IGBT Connections by a Gate Control Circuit

G. Belverde, M. Melito, S. Musumeci
STMicroelectronics
Stradale Primosole, 50
95121 Catania, Italy
Tel. +39 095 7407576               Fax +39 095 7407099               
e-mail maurizio.melito@st.com

A. Raciti
Department of Electric Electronic and Systems Engineering
University of Catania
Viale A. Doria, 6
95125 Catania, Italy
Tel. + 39 095 7382323              Fax + 39 095 339535               
e-mail araciti@dees.unict.it

In the field of power equipment, the parallel connection of insulated gate devices, such as IGBTs or Power MOSFETs, is pursued in order to obtain power switches with higher current carrying capability.  The control of the balanced sharing of the currents during the parallel operations is a key issue worth being considered.  The proposed technique allows obtaining safe commutations without thermal stresses on the single device by exploiting the actions of a simple and effective control circuit, which intervenes on the gate side of the power devices.  The method does not show limitations on the number of paralleled devices, which can be managed.  Several experimental tests have been carried out in order to demonstrate the validity and correctness of the proposed approach.

The Sensitivity Analysis of the Base Resistance for the BRT Employing Corrugated P-Base

Jae-Keun Oh, Moo-Sup Lim, Min-Koo Han and
School of Electrical Engineering #50, Seoul National University
hinlim-Dong Kwanak-Ku
Seoul 151-742, Korea
Tel : +82-2-880-7254,  Fax : +82-2-873-9953
E-mail : worms1@snu.ac.kr
http://emlab.snu.ac.kr

Yearn-Ik Choi
School of Electronics Engineering
Ajou University
Wonchun-Dong
Suwon 442-749, Korea,

We report the process sensitivity of the self align corrugated p-base resistance which improves the electric characteristics of the CB-BRT and the SB-EST. Experimental results and simulation results show that the process sensitivity of the corrugated p-base resistance is much better than that of the conventional p-base.

DS2.2: Topic 1: Devices
(A. Lindemann, IXYS Semiconductor, Germany, J. Lutz, Technical University of Chemnitz, Germany)

Charge compensated MOSFET - How close to the ideal power switch?

Marco Puerschel, Anton Riedlhammer, Dr. Ilia Zverev
Infineon Technologies
Balanstrasse 73
81609 Munich
Fax.: ++49-89-23423506

Theoretical properties of an ideal power switch such as power losses and noise generation (EMI) are discussed. Each of these properties, their interdependence and trade off are described. The principle of compensation will be explained and correspondence between charge compensated MOSFET (CoolMOS) and theoretical ideal power switch are discussed.

IGBT Module Thermal Simulation

Marcin JANICKI, Andrzej NAPIERALSKI
Department of Microelectronics & Computer Science
Technical University of Lodz
Al. Politechniki 11, 93-590 Lodz, Poland
Phone: +48 42 6312645
Fax: +48 42 6360327
e-mail: janicki@dmcs.p.lodz.pl
www.dmcs.p.lodz.pl

This paper presents results of thermal simulations performed for an IGBT hybrid power module.
Two different thermal models of the circuit were proposed. The more complex model is solved numerically using the finite differences method; the other is solved analytically employing the Fourier method. The simulation results are validated with infrared measurements. The discussion on the influence of thermal model simplification on its accuracy is included.

Eddy current losses in SMPS transformers: a full-frequency-range review of 2D effects inside the windings

Frédéric ROBERT, Pierre MATHYS
Université Libre de Bruxelles - Elmitel CP165/56
Av. F.D. Roosevelt 50
B1050 Brussels, Belgium
Tel +32-2-6502865 / Fax +32-2-6477108
frrobert@ulb.ac.be
pmathys@ulb.ac.be

Jean-Pierre SCHAUWERS
Cherokee Europe
Bd de l'Europe 131
B1301 Wavre, Belgium
Tel +32-10-438373
j.schauwers@cherokee.be

This paper gives an original catalog of possible 2D effects governing eddy current losses in transformer windings regarding conductor's type and frequency. The main goal is to provide industrial designers a deeper understanding of the 2D fields in real transformers. A new aspect covered in this paper is the analysis of 2D effects on the whole frequency range, including harmonic frequencies. Experimental validation is provided by measuring AC resistance of real magnetic devices.

Arrangement of Conductors to Obtain Turn-Coupling in Thick-Film Integrated Inductors for Power Converters

Miguel J. Prieto, Juan M. Lopera, Alberto M. Pernيa, Juan A. Martيn, Fernando Nuٌo
UNIVERSIDAD DE OVIEDO – ءREA DE TECNOLOGحA ELECTRسNICA
Campus de Viesques, s/n
Gijَn (Asturias) - Spain
Tel.: + 34 – 985 18 25 67 / Fax.:  + 34 – 985 18 21 38
e-mail: mike@ate.uniovi.es

Even though magnetic components are still one of the key points when trying to reduce the size and weight of power converters, not many solutions have been suggested that allow obtaining them through an integration process. Thick-film technology has been presented in a recent work as an alternative to produce integrated power inductors. However, the thick-film structures do not succeed in providing coupling between turns. This paper discusses the way to distribute windings in such structures in order to obtain thick-film power inductors with turns coupled, which will further contribute to the size reduction of these components.

Measurement of the Radial Cathode Current Distribution During the Turnoff-Process of a 4-kA-IGCT Under Different Driving Conditions

Eberhard U. Krafft
Ruhr-Universit Bochum EAEE
D-44780 Bochum
Phone: ++49 234 / 32 23890
Fax: ++49 234 / 32 14597
krafft@eaee.ruhr-uni-bochum.de

Andreas Steimel
Ruhr-Universit Bochum  EAEE
D-44780 Bochum
Phone: ++49 234 / 32 23980
Fax: ++49 234 / 32 14597ｵ
steimel@eaee.ruhr-uni-bochum.de

To investigate the radial cathode current distribution of an IGCT during the turnoff process a measurement adapter has been built, which enables to register the currents of the separate rings of cathode islands by means of Rogowski coils. Measurements with different driving gate-cathode voltages are presented.

Introduction

In this paper an approach is shown how to qualify by measurement the homogeneity of the cathode current during the IGCT turnoff process which is outlined as one of the main advantages of the IGCT concept [1]. The element under test is the 5SGY35L4502 from ABB.
The IGCT is measured in the test circuit shown in fig. 1. It is possible to add a RCD snubber to limit the du/dt-increase. That becomes necessary if the IGCT is driven in such a weak way (with low negative gate-cathode driver voltage) that current filamentation threatens, to protect the element.

The influence of air gap position and winding position on the inductance in high frequency transformers

S. Voss,   H. Roßmanith,   M. Albach
Lehrstuhl für Elektromagnetische Felder
Friedrich-Alexander-Universität
Cauerstr. 7
D – 91058 Erlangen,  Germany
+49(0)9131 85 -28952 (phone) / -27787 (fax)

The number of turns needed for the realisation of a given inductance on a given core is normally calculated by means of the A_L-value specified in data books. Unfortunately this A_L-value is not a constant value, a variation of the inductance L of 70% has been measured only by changing the position of the turns inside the winding area. In this paper the influence of the gap position and especially of the position of the turns on the A_L-value is demonstrated and the necessary equations for calculating this influence are presented.

Understanding MBS turn-on behaviour in light dimmer applications

R. Ferragut ^(1,2), L. Gonthier ⁽²⁾, D. Magnon ⁽¹⁾, J.C. Lebunetel ^(1)
(1) Power Microelectronics Laboratory, Tours University
⁽²⁾ STMicroelectronics, Tours
16, Rue Pierre et Marie Curie, BP7155
37071 Tours Cedex 2, France
E-mail: romain.ferragut@st.com

Nowadays, EMC standard compliance is part of the constraints that every electronic and electrical system must fulfil. Power device switching is the main cause of conducted electromagnetic interferences produced by power conversion systems. Studies and optimisations of switching waveforms are therefore of major concern in power electronics. Several works deal with this subject. They define relations between waveforms and conducted interferences. As a result, sinusoidal shaped switching waveform is shown to be the optimal one. In order to understand how to achieve such waveform, the impact of MBS electrical parameters on switching waveforms should be investigated. This paper presents a simple electrical representation of MBS during turn-on in a resistive or low inductive load. Some conclusions on the influence of MBS electrical parameters on switching waveforms are drawn from it.

Loss analysis of integrated halfbridge drivers

Georg Sauerlaender
PHILIPS RESEARCH LABORATORIES
Weisshausstrasse 2
52066 Aachen, Germany
Tel. +49 241 6003 272 / Fax +49 241 6003 442
georg.sauerlaender@philips.com
http://www.research.philips.com

The losses of halfbridge drivers with integrated levelshifter have been analysed. The different loss mechanisms have been identified resulting in an empirical formula to predict the driver losses as a function of frequency, supply voltage, bus voltage and MOSFET parasitics. Four easily measurable indicators are proposed to compare the efficiency of different drivers.

Edge Terminations for 6.5 kV IGBTs

M. Vellvehi, D. Flores, S. Hidalgo, J. Rebollo, J. Millán
CENTRE NACIONAL DE MICROELECTRÒNICA  (CNM-CSIC)
Campus U.A.B. 08193 Bellaterra (Barcelona), Spain
Tel: +34 93 594 77 00, Fax: +34 93 580 14 96,
e-mail: miquel.vellvehi@cnm.es, http://www.cnm.es

L. Coulbeck, P. Waind and D. Newcombe
DYNEX SEMICONDUCTOR
Doddington Road, United Kingdom LN6 3LF
Tel: +44 1522 502 883, Fax: +44 1522 502 747,
e-mail lee_coulbeck@dynexsemi.com
http://www.dynexsemi.com

This paper is addressed to the design and optimisation of Junction Termination Extension and Floating Guard Rings edge termination structures to integrate 6.5 kV IGBT devices. The developed edge termination structures are extensively analysed through numerical simulations, and experimental data on fabricated diode structures are correlated with simulation results showing the feasibility of the proposed techniques.

Sizing Method of External Capacitors for series association of Insulated Gate Components

PO. Jeannin, D. Frey, JL. Schanen
Laboratoire d’Electrotechnique de Grenoble
CNRS UMR 5529 INPG/UJF,
BP 46, F – 38402 SMH cedex,
Grenoble, France.
Phone: (33) 476826299  Fax: (33) 476826300
Jean-Luc.Schanen@leg.ensieg.inpg.fr
Pierre-Olivier.Jeannin@leg.ensieg.inpg.fr

In this paper, the behavior of drain-to-source voltage evolution of insulated gate components during transients is studied. Analytical formula is obtained, which takes into account eventual external capacitors. The minimal value of the Cds external capacitance to impose the dVds/dt can be deviated from this study. As an application, a two MOSFETs series association is proposed, and validated using both simulation and measurement for using external Cds or Cgd capacitors.

Achievement of a new peripheral planar structure Supporting a symmetrical blocking voltage

O. CAUSSE, P. AUSTIN, J.L. SANCHEZ, G. BONNET, E.SCHEID
LAAS-CNRS
7 avenue du Colonel ROCHE
31077 Toulouse, France

Two new peripheral planar structures of junction termination type allowing symmetrical blocking voltage are presented. The first one is considered like an ideal structure, but requires a specific packaging. The second one is well suited for classical packaging using brazing. Two technological solutions to realise insulated P⁺ vertical walls implemented into these new peripheral structures are also presented: the thermomigration of aluminium in silicon and deep trenches filled with highly boron doped polysilicon.

A simple analytical approach for the thermal modeling of power devices and circuits

N. Rinaldi
Department of Electronics and Telecommunications Engineering
University of Naples “Federico II”
Via Claudio 21, 80125, Naples, Italy
Tel.: +39-(0)81 7683517 / Fax: +39 (0)81 5934448
email: nirinald@unina.it

A new analytical thermal model of multilayer substrates is presented. Based on the integration of the temperature field generated by a point source and on a generalization of the method of images, the model is straightforward to implement and computationally efficient. Approximate expressions for the thermal resistance in multilayer substrates are derived for the first time.

Modeling HF Resistance of Parallel Windings in Magnetic Components

R. Prieto, J.A. Cobos, J. Uceda
Universidad Politécnica de Madrid (UPM)
División de Ingeniería Electrónica (DIE)
José Gutiérrez Abascal, 2
28006 Madrid SPAIN
email: rprieto@upmdie.upm.es
M.Christini
Ansoft Corporation
Four Station Square
Suite 200
Pittsburgh, PA 15219-1119

The use of turns connected in parallel is a very common practice when HF magnetic components are designed. The current density and the frequency usually determine the number of parallel turns needed in each design. Since the current is not equally necessarily distributed equally through each parallel strand, the modeling of this effect, accounting for the winding strategy (interleaving) and frequency effects (skin and proximity), is not an easy task.  This work presents an analysis of this effect as well as possible solutions to address the modeling of these situations.

A New Protection Circuit for 4.5kV Current Sense IEGT

Hiromichi Tai
Toshiba Corporation
Power systems & services company
Phone: +81-42-333-2567
Fax: +81-42-340-8060
E-mail: hiromichi.tai@toshiba.co.jp

Mitsuhiko Kitagawa
Toshiba Corporation
Semiconductor company
Phone: +81-93-562-1491
Fax: +81-93-562-1582

This paper presents a new type of short-circuit protection circuit for current sense IGBT.  Proposed protection circuit has three stages structure that enables precise current sensing and stable current limit operation. An evaluation was made using 4.5kV current sense press pack IEGT and the experimental results show good performance of this combination.

Thermal modeling and behavior of ultracapacitors for electric vehicle applications

B. L. Meng, H. Gualous, A. Djerdir, A. Berthon, J.M. Kauffmann
L2ES – IGE (LRE-T31, INRETS)
2, avenue Jean Moulin 90000
BELFORT, FRANCE

D. Bouquain
CREEBEL
1, rue Morimont 90008
BELFORT, FRANCE
Telephone/Fax: 003384578215 / 0033384570032
e-mail : gualous@ige.univ-fcomte.fr

The aim of this paper is to define the thermal behavior of ultracapacitors using an electrical model taking into account thermal variations of the device and its environment. Ultracapacitors of 2700 F and 3700 F have been tested. An equivalent circuit is proposed to describe the electrical and the thermal behavior of the ultracapacitors. The model obtained is implemented in Saber and Spice software for simulation. The equivalent circuit response and the experimental results are compared and analyzed.

Improving Metalized Polypropylene Film Capacitors Reliability Achieved by a Better Design

M.H. EL-HUSSEINI, P. VENET, G. ROJAT
CEGELY-UCBL UMR-CNRS 5005
43, Bd du 11 novembre 1918
69621 Villeurbanne Cedex
FRANCE

M. FATHALLAH
CEGELY-INSA UMR-CNRS 5005
20 Avenue Albert Einstein
69621 Villeurbanne Cedex
FRANCE

Aging of MPPF capacitors have been studied in this paper with the aim to improve their reliability regarding their design. The study is performed for three series of capacitors having the same capacitance but different geometry. Two types of aging were considered for the study. At the first stage, the three series of capacitors are subjected to electric stresses which consist in passing a strong sinusoidal current through the component under test. The test current is selected in such a way as not to exceed, in the worst of cases, maximum temperature supported by the element, namely around 90 °C, where the polypropylene starts to experience a shrinkage phenomenon. As a second test, the elements were overstressed by voltage and temperature. The experiments proved that long capacitor deteriorates faster than a plate-shaped having the same features.

Commutation processes in a Zero Voltage Switching Hybrid DC switch

Polman H., Ferreira J.A.
Delft University of Technology
Electrical Power Processing group
PO Box 5031
2600 GA DELFT, the Netherlands

Kaanders M., Evenblij B., Van Gelder P.
TNO Prins Maurits Laboratory
Research Group Platform Technology
PO Box 45, 2280 AA RIJSWIJK
The Netherlands

In a DC switch arcing is prevented by combining a semiconductor switch with the mechanical switch. A 600V/6kA switch has been designed and constructed. The hybrid switch is bi-directional and uses Zero Voltage Switching. In principle the ZVS topology consists of three parallel branches. The first contains the mechanical switch, the second a commutation semiconductor and the third an energy absorber. In this paper the commutation process in the hybrid switch is analysed. Three commutation intervals can be distinguished. Modelling and simulations of these three commutation intervals are presented. A prototype switch has been designed and built. The modelling and simulations are verified by experiments conducted on the prototype switch. The prototype shows substantially reduced arcing. The calculations and the simulations are in good agreement with the experimental results.

Novel high frequency modular transformer with coaxial windings

Boguslaw Grzesik, Mariusz Stepien
SILESIAN UNIVERSITY OF TECHNOLOGY
Ul. B. Krzywoustego 2
44100 Gliwice, POLAND
Phone: +48 32 237 1247; Fax: +48 32 237 1304
e-mail: grzesik@polsl.gliwice.pl
e-mail: stemar@polsl.gliwice.pl

The paper contains proposal of novel HF modular transformer of very high efficiency (above 99.0%) and of very high power density (above the densities reached until now). The transformer has been analyzed by means of finite element method (FEM) using ANSYS software. It has windings toroidal in shape formed of coaxially arranged pipes that are placed inside of ferromagnetic core. The transformer operates at 1MHz having approximately 1.8 kW of output power.

DS2.3: Topic 2: Soft switching converters (resonant, ZVS, ZCS)
(J. Kyyra, Helsinki University of Technology, Finland, L. Gertmar, ABB, Sweden)

Design and Implementation of a Quasi-Resonant DC Link Converter

Per Karlsson,  Mats Alaküla
Department of Industrial Electrical Engineering and Automation
Lund University, Lund, Sweden
Phone: +46 46 222 92 90
Fax: +46 46 14 21 14

Martin Bojrup
Emotron AB
Helsingborg, Sweden
Phone: +46 42 16 99 00
Fax: +46 42 16 99 49

Lars Gertmar
ABB Corporate Research
Vنsterهs, Sweden
Phone: +46 21 32 31 31
Fax: +46 21 32 32 64
per.karlsson@iea.lth.se
martin.bojrup@emotron.se,
mats.alakula@iea.lth.se
lars.gertmar@iea.lth.se
 

In this paper, a passively clamped quasi-resonant DC link converter is analysed, implemented and evaluated in a battery charger application. Design expressions for selection of passive component values, based mainly on the specified maximum output voltage derivative and the duration of the zero voltage interval, are given. Design of the inductive components and selection of appropriate power semiconductors for the quasi-resonant DC link are investigated. The main problems regarding power electronic design of these components are also discussed. The quasi-resonant DC link waveforms are measured and the converter efficiency is measured and compared to a hard switched case.

Diesel Emission Control System Using Soft Switching PWM High Frequency Inverter

Sachio Kubota, Nobuo Ogawa, Yoshihiro Shimaoka
Toba National College of Maritime Technology,
1-1 Ikegami-cho Toba-shi, Mie 517-8501
Toba, JAPAN
TEL&FAX: +81-599-25-8005
E-mail: kubota@toba-cmt.ac.jp
 

Yoshihiro Hatanaka
Tokyo University of Mercantile Marine
2-1-6 Echujima Koto-ku, Tokyo 135
Tokyo, JAPAN
TEL&FAX: +81-3-5245-7412
E-mail: hatanaka@ipc.tosho-u.ac.jp
 

This paper describes the diesel emission control system, and the soft switching PWM high frequency inverter. In order to equip a diesel engine with the diesel emission system, an output power in the proposed inverter is controlled according to change of the generating power of an engine. In this paper, the characteristics of this inverter is analyzed

Soft-Switching Inverter Topologies for Linear Motor Drive Applications Using Auxiliary Switches

Johanna M.A. Myrzik, J. L. Duarte
Technical University of Eindhoven,
Department of Electrical Engineering,
Den Dolech2, P.O. Box 513
5600 MB Eindhoven, The Netherlands
+31 40 247 3566 (ph)/+31 40 243 4364 (fax)
j.m.a.myrzik@tue.nl
www.tue.nl

Korneel Wijnands
Prodrive B.V.
P.O. Box 28030
5602 JA Eindhoven, The Netherlands
+31 40 2676 200 (ph)/+31 40 2676 201 (fax)
kw@prodrive.nl
www.prodrive.nl

In order to achieve higher power density, higher efficiency and lower EMI and sub-harmonics ratings soft-transition techniques are applied in DC -AC converter design. This kind of soft-switching technique enables the implementation of low-noise PWM waveforms by means of auxiliary switches. A comparison study of two recently developed soft-switching inverter topologies is carried out to characterize the stress and size of the inverter components and the loss mechanisms. The application for high-speed linear motors (> 1.0m/sec) stands in the foreground. Limitations of switching frequency and duty cycle gives a predication of the maximum output current bandwidth and power output.

Industrial 20 kHz/150 kVA Insulated Soft Switching DC-DC Converter with No Auxiliary Circuit

J.P. Lavieville, P. Baudesson, L. Gilbert
ALSTOM TECHNOLOGIES PERT
9 rue ampere
91345 Massy, France
+33(0)1 60 13 40 29
+33(0)1 60 13 26 26
jean-paul.lavieville@techn.alstom.com
            
J-M. Bodson
ALSTOM BELGIUM / TRANSPORT
BP 4211        
B-6001 Charleroi, Belgium      
+32(0)71 44 52 41     
+32(0)71 44 57 72
jean-marie.bodson@transport.alstom.com

Higher switching frequencies are the key to reduce the size and weight of passive energy storage elements. The drawback of this action is the increasing of the switching losses. One possible solution to the inevitable compromise frequency/losses is the use of soft switching techniques.
The present paper highlights the analysis and the results obtained of an efficient 150 KVA DC-DC converter including a high frequency ferrite transformer using zero switching loss.
These results are not considered final by the authors, but rather as a beginning of a series of studies base on this family of topology.

Review of modelling methodologies to facilitate rapid simulation of high order resonant converters.

M. P. Foster, H. I. Sewell, D. A. Stone & C. M. Bingham.
Department of EEE,
University of Sheffield
Mappin Street, Sheffield, S1 3JD, U.K.
Tel. +44 (0) 114 2225195
Email: elp00mpf@sheffield.ac.uk

In recent years, the importance of resonant converter topologies to the power conversion industry has increased significantly, with the requirement for increasingly smaller power supplies for more compact electronic equipment, and higher efficiency supplies for increased battery life and/or to meet environmental constraints.  Furthermore, the improved performance characteristics that can be obtained by employing high-order tank circuits have attracted interest in complex resonant power circuitry.  However, hand-in-hand with the increased complexity of such high-order resonant converters, comes the increased difficulty in modelling of their performance at the design stage. This is predominantly due to the fact that appropriate converter topologies exhibit several degrees of freedom, and also tend to have long settling times compared to the switching period. This paper aims to contrast and compare a number of techniques that have been proposed to address these, and other pertinent issues.

Two New Concepts Bridging Between SRC (fs>1) And PWM Converters Based On Loosely Coupled Inductive Couplers

By Wan Li, G. Maggetto, Ph. Lataire
TW-ETEC, VUB
Pleinlaan 2,
Brussels B-1050, Belgium
Tele: +32 2 629 2800, Fax: +32 2 629 3620
Email: tw56854@vub.ac.be
http://etecnts1.vub.ac.be/etec/

The resonant converters are not transparent. With the introduction of LCIC or CT-LCIC, the SRCs will be too complicated to be analytically solved. When operating above the resonant frequency, the SRCs behave similar to their PWM counterparts. The resonant capacitor can be considered as “negative inductance” that can be combined the leakage inductance of the resonant tank; thus, SRC (fs>1) is simplified as PWM converter.
When it is driven by fixed frequency phase-shifted command scheme, the SRC (fs>1) may operate under DCM mode, where two resonant frequencies affect the converter’s behavior. The concept of “Switching frequency shift” can equivalent such two resonant frequencies effect with higher switching frequency under one resonant frequency.
By deploying those two concepts, the steady-state characteristics of SRCs (fs>1) can be well approximated. The results are experimentally verified.

Characteristic analysis of ZVS-HB type high frequency resonant inverter according to the variable capacitance of the DC voltage source separation capacitor

J. S. Won, D. H. Kim
School of Electrical and Electronic Engineering, Yeungnam University, South Korea

Phone : +82-53-810-2488, Fax : +82-53-813-8230
E-mail : jsuni@chollian.net

D. Y. Jung, B. S. Lee
Dept. of Control and Instrumentation Engineering
Samchok National University, South Korea
Phone : +82-33-570-6383, Fax : +82-33-570-6389
E-mail : dyjung@samchok.ac.kr

J. H. Kim
Dept. of Electrical Engineering
Graduate School of Nagoya University, Japan
Phone : +81-52-789-2778, Fax : +81-52-789-3140
E-mail : kimjh@okuma.nuee.nagoya-u.ac.kr

This paper presents about an example of circuit design and characteristics of inverter according to the variable capacitance of the DC voltage source separation capacitor used in ZVS-HB type high frequency resonant inverter. The soft switching technology known as ZVS is used to reduce turn off loss at switching. In the event the capacitance of the DC voltage source separation capacitor is varied, the analysis of inverter circuit has generally described by using normalized parameter and operating characteristics have been evaluated in terms of switching frequency and parameters. According to the calculated characteristics value, a method of the circuit designs and operating characteristic of the inverter is also presented in this paper. In addition, this paper proves the validity of theoretical analysis through the experiment. This proposed inverter shows that it can be practically used in future as power source system for the lighting equipment of discharge lamp, DC-DC converter etc.

Managing ultracapacitors energy to feed electric vehicles DC bus

A. Djerdi,  H. Gualous, A. Berthon
L2ES, IGE  2 AV.
Jean Moulin 90000 Belfort

D. Bouquain
CREEBEL
1, rue Morimont 90008 Belfort
djerdir@ige.univ-fcomte.fr

The aim of this paper is to insert the ultracapacitors into an electric vehicle. Ultracapacitors are intended to drive electric motors when overloaded. They also recover energy coming from motors during an electric braking. Finally, they are charged starting from the vehicle DC bus. A DC/DC converter able to carry out the above functions and based on the boost/buck topology has been proposed.

An Optimal Lossless Commutation PWM Two Level Forward Converter Operating like a Full Bridge

R. M. Finzi Neto; J. B. Vieira Jr. (IEEE Member); E.A. Coelho; L.H.S.C. Barreto; V. J. Farias, L. C. Freitas^(*)(IEEE Member)
(*) Corresponding author.
Universidade Federal de Uberlândia
Faculdade de Engenharia Elétrica
Campus Santa Mônica - Bloco 3N
38400-902 - Uberlândia - MG – Brazil
Phone / Fax : +55 34 3 239-4166
e-mail : freitas@ufu.br

This paper presents an optimal topology for the combination of two forward structures, attached to the same transformer and operating like a full bridge. The transformer and the output filter operate with twice of the forward switching frequency.
Each one of the forward converters has a lossless commutation cell that allows for high switching frequency, high power operation and high efficiency to a wide load range.
Complete mathematical analysis and experimental results will be presented in the final version of this paper.
 

Auxiliary Resonant DC Link-Assisted Soft Switching Inverter for AC Servo Motor Drive and Its Performance Evaluations

Junji Yoshitsugu*, Masayuki Ando, Eiji Hiraki, Mutsuo Nakaoka

The Graduate School of Science & Engineering,
Yamaguchi University
2-16-1 Tokiwadai, Ube,
Yamaguchi, 755-8611, JAPAN
Tel.&Fax: +81-836-85-9472
junji@pe-news1.eee.yamaguchi-u.ac.jp

Kenji Inoue
Research & Development Laboratory
Shinko Electric Co., Ltd.
100 Takegahana, Ise
Mie, 516-8550, JAPAN
Tel.:+81-596-36-3180  Fax:+81-596-36-3974
inoue-k@ise.shinko-elec.co.jp
URL:http://www.shinko-elec.co.jp

This paper presents an auxiliary active quasi-resonant DC link snubber-assisted three phase voltage source type soft-switching inverter using IPM (Intelligent Power Module) for AC servo motor drive applications. The operation of this quasi-resonant DC link snubber circuit and its circuit parameter design approach are described and three phase voltage source soft switching inverter using a quasi-resonant DC link snubber treated here is discussed from an experimental point of view. In addition to this, the motor current and the motor speed response under the soft switching inverter are compared with that of the conventional hard switching inverter. The effectiveness of the soft switching inverter-fed permanent magnet AC servo motor drive system is evaluated on the basis of the common mode current in the inverter driven motor side as compared with that of the conventional hard switching inverter-fed permanent AC servo motor drive system.

New Active Resonant Topology of Voltage Source Three Phase Soft Switching PFC Rectifier

Eiji Hiraki,Masanobu Yoshida,Mutsuo Nakaoka
Department of Electrical and Electronics Engineering
Yamaguchi University
Tokiwadai,Ube
Yamaguchi,755-8611,Japan
TEL :+81-836-85-9472 /FAX :+81-836-85-9401
E-Mail :hiraki@pe-news1.eee.yamaguchi-u.ac.jp

This paper presents a new active quasi-resonant snubber circuit topology (Auxiliary Quasi-Resonant Commutation Block-Link Snubber;ARCB)which is suitable for the voltage source type three phase PWM inverters /PFC rectifier,which can operate under a principle of Zero Voltage Soft Switching (ZVS)commutation.Its operating principle,and the steady-state operationg performances of the digitally-controlled three phase soft switching PWM-PFC rectifier system with an instantaneous power feedback scheme are discribed in this paper.The circuit parameter design method are illustrated and evaluated on the basis of computer-aided simulation analysis.

Modelling, Analysis and Design of a Three-Phase Series-Parallel Resonant DC-DC Converter employing Capacitive Output Filter

Sunil Akre
Dr. Michael Egan
PEI Technologies
Department of Electrical Engineering
University College Cork
IRELAND
sakre@pei.ucc.ie

A three-phase resonant dc-dc conversion topology is presented and analyzed. The converter is analyzed using a linear per-phase equivalent circuit model. Standard star-delta, delta-delta or delta-star connection can be employed for the isolation transformers. A systematic step-by-step design procedure is given. The impact of the star-delta or the delta-star configuration, on the converter performance is studied and the results are presented. Advantages of the converter includes soft-switching for all of the inverter switches, low input and output ripple, a narrow control frequency range and use of leakage inductance as part of resonant inductor. The topology is suitable for high-power, high-frequency, high-voltage applications.

THE POWER REGULATOR WITH INHERENT OVERLOAD PROTECTION

Marko Vukšić
SNAP Ltd.
Pojišanska 25
21000 Split, Croatia
Tel./Fax +385 21 543 272
snap@st.tel.hr

Slobodan M. Beroš
University of Split, ECE Dept.
R Boškovića b.b.
21000 Split, Croatia
Tel. +385 21 305 611
sberos@fesb.hr

The implementation of the half bridge ZVS multiresonant DC/DC converter in mains powered power regulator application is presented. Converter is powered with the full wave rectified mains voltage only and loaded with resistive load. A prototype development is based  upon performed analysis of the DC transfer ratio and experimental measurement of the small signal transfer function. The  prototype delivers 100W at 12V RMS output voltage at full load. The power delivered to load can be dimmed down to zero. The converter shows inherent overload protection. The power regulator is suitable for the resistive loads with high initial current requirements such as halogen lamps.

Reduction of Linearity Range of Space Vector PWM in Soft Switching Converters

Dr. A. Radan

Power Electronics Lab.

Power & Water Institute of Technology

P.O.Box: 16765-1719 Tehran – IRAN

Tel.: +98 21 7310041-4 Fax: +98 21 7310425
Email: radan@pwit.ac.ir

The duration of Zero Voltage Transitions (ZVT) in soft switching converters restricts the minimum duration of voltage vectors of Space Vector PWM (SVPWM) which can be switched. This affects the linearity range of space vector modulation in soft switching converters. This paper investigates the restrictions imposed by the duration of ZVT on SVPWM resulting in reduction of the linearity range of modulation in these converters. The conventional continuous SVPWM and an optimised discontinuous SVPWM are compared with each other regarding maximum available linear modulation index. The results show that the discontinuous SVPWM makes a higher maximum linear modulation index available in soft switching converters, but this maximum can not be reached the value 1.15 of hard switching converters.

Operation And Steady-State Analysis Of ZVS-PWM Converters Based on Loosely Coupled Inductive Couplers

By Wan Li, G. Maggetto, Ph. Lataire
TW-ETEC, VUB
Pleinlaan 2,
Brussels B-1050, Belgium
Tele: +32 2 629 2800, Fax: +32 2 629 3620
Email: tw56854@vub.ac.be
http://etecnts1.vub.ac.be/etec/

An inductive charging system is a DC-DC converter that is electrically separated by a Loosely Coupled Inductive Coupler (briefly, LCIC). A LCIC possesses asymmetrical leakage inductance on both the primary and the secondary side, which cannot be ignored comparing to magnetizing inductance. Basically, LCIC have two structures: single secondary coil (LCIC) and center-tapped secondary coil (CT-LCIC).
When it is driven by fixed frequency phase-shifted command scheme, the LCIC-based converter behaves as a soft-switching PWM converter. According to LCIC structure and its corresponding ouput rectifier topology,  the above-mentioned converters can further be classified as ZVS-PWM-FB and ZVS-PWM-CT converters. Both of them take use of the parasitic capacitors of the switches and the leakage inductances of LCIC to realize soft-switching.
Apart from large asmmetrical, leakage inductances exist in its primary and seconday side of LCIC, for CT-LCIC, those two secondary leakage inductances will couple themselves and exhibits “lekage inductance coupling effect”.
Such large aymmetrical leakage inductances on LCIC and the leakage inductance coupling on CT-LCIC have strong influence on the  behaviors of a PWM converters,  and thus,  should be investigated.

Quantitative Analysis on Switching Surge in Soft-switching Converters

Toru HIGASHI
Faculty of Education
Kumamoto University
Kumamoto
860-8555 JAPAN
+81-96-342-2652/+81-342-2510
higashi@kumamoto-u.ac.jp

Noise characteristics on switching surge in Soft-switching converter family such as Current-mode resonant type, Voltage-mode resonant type, Active-clamp type have been quantitatively studied by experiment and analysis. The mechanisms of noise generation for each converter are revealed using very accurate high-frequency model, and noise characteristics have been compared among them.

Multiresonant converter: 12kW prototype for batteries and telecommunication equipments

DAKYO B., J. M. BLAQUIERE, P. REGHEM,
GREAH Université du Havre
25, rue Ph. LEBON
BP 540 76058
LE HAVRE, France
Tel :+33 2 32 74 43 30
Fax :+33 2 32 74 43 48
dakyo@univ-lehavre.fr
http://www.univ-lehavre.fr/recherche/greah/

The multiresonant concept is adopted for soft-switching benefits. The theoretical analysis of the converter are tied to mode multiplicity and the knowledge of converter behaviour in frequency domain. We propose very efficient system theory and practice wich takes in account transformer leakage inductance for a userdefined high frequency range of operation.

Electromagnetic Induction Eddy Current based Far Infrared Rays Radiant Heating Appliance using Soft Switching PWM High Frequency Inverter

H. Tanaka, H. Sadakata, Mamun A. AL, Chu En Hui, A. Okuno and M. Nakaoka(Prof.Dr-Eng)
YAMAGUCHI UNIVERSITY
2-16-1, Tokiwadai, Ube
Yamaguchi, 755-8611, Japan
nakaoka@pe-news1.eee.yamaguchi-u.ac.jp

This paper presents an innovative prototype of a conceptual electromagnetic induction type far infrared rays radiant heating appliance using voltage fed quasi-resonant ZVS-PWM high frequency inverter which can operate at constant frequency variable power regulation scheme. This consumer power appliance is more cost effective because of high frequency, safety, cleanliness, compactness and rapid temperature response.

DS2.4: Topic 2: Power converter circuits and control
(R. Kennel, University of Wuppertal, Germany)
 

A Commutation Strategy of the Rectifier with Sensing  DC Current of Voltage Source Inverter without DC Link Components for Motor Drive

Kenichi Iimori, Katsuji Shinohara, Mitsuhiro Muroya and Hiromi Sako
Department of Electrical and Electronics Engineering,
Faculty of engineering, Kagoshima University
1-21-40,Korimoto
Kagoshima, Japan

This paper describes a commutation strategy, which does not require snubber circuits, of the rectifier section of the voltage source inverter without dc link components. In this proposed commutation strategy, each switching devices of the bi-directional switches are controlled independently with sensing dc current direction. The proposed strategy has been verified by computer simulation and experimental test on 0.75kW induction motor drive.

A Novel Control Scheme for the Multilevel Rectifier/Inverter

Bor-Ren Lin
Department of Electrical Engineering
National Yunlin University of Science and Technology
Touliu City
Yunlin 640
Taiwan, ROC
Fax:+886-5-5312065
email: linbr@pine.yuntech.edu.tw

A novel three-level pulsewidth modulation (PWM) rectifier/inverter is proposed. The single-phase three-level rectifier with power factor correction and current harmonic reduction is proposed to improve the power quality. Three-phase three-level neutral point clamped (NPC) inverter is adopted to reduce the harmonic content of the inverter output voltages and currents. In the adopted rectifier, a switching mode rectifier with two AC power switches is adopted to draw a sinusoidal line current in phase with mains voltage. The switching functions of power switches are based on a look-up table. To achieve a balance DC-link capacitor voltage, a capacitor voltage compensator is employed to achieve this goal. In the NPC inverter, the three-level PWM techniques based on the sine-triangle PWM and space vector modulation are used to reduce the voltage harmonics and drive an induction motor. The advantages of the adopted three-level rectifier/inverter are 1) the blocking voltage of power devices (T1, T2, S_a1~S_c4) is clamping to half of the DC-link voltage, 2) low conduction loss with low conduction resistance due to low voltage stress, 3) low electromagnetic interference, and 4) low voltage harmonics in the inverter output. Based on the proposed control strategy, the rectifier can draw a high power factor line current and achieve two balance capacitor voltages. The current harmonics generated from the adopted rectifier can meet the international requirements. Finally, the proposed control algorithm is illustrated through experimental results based on the laboratory prototype.

P.W.M. Current converter for electric energy production systems from fuel-cells.

C. Rivas, A. Rufer
Swiss Federal Institute of Technology Lausanne
CH-1015 Lausanne
Switzerland
+41 21 693 3656 / +41 21 693 2600
carlos.rivas@epfl.ch
http://leiwww.epfl.ch

Fuel Cells are destined to supply electric energy beginning from primary resources. A static DC-AC converter is necessarily inserted between the fuel cells and the distribution network. This paper describes a new P.W.M. strategy for a current source inverter. This modulation strategy reduces the energy losses and harmonics in the P.W.M. current source inverter. This technique allows the P.W.M. current source inverter to become a new feasible solution to adapt a low continuous voltage into a three-phase voltage of higher amplitude.

An Averaged AC Models Accuracy Evaluation of Non-Isolated Matrix-Reactance PWM AC Line Conditioners

Igor Y. Korotyeyev, Zbigniew Fedyczak, Ryszard Strzelecki, Krzysztof P. Sozański
Technical University of Zielona Gَra, Poland
Institute of ElectRIcal Engineering,
ul. Podgَrna 50
65-246 Zielona Gَra, Poland
tel.: (+48 68) 3282528,  fax: (+48 68) 3254615
e-mail:i.koroteev@iep.pz.zgora.pl
z.fedyczak@iep.pz.zgora.pl
r.strzelecki@iep.pz.zgora.pl

This paper deals with matrix-reactance PWM AC line conditioners (MRACLCs). Theoretical preliminary to averaged modelling of these conditioners with current time averaging operator and averaging errors estimation for fundamental harmonics of state variable is presented. On the base of theoretical consideration there is steady-state averaged AC models quantitative accuracy evaluation formulated in this paper. As an application of the theory, examples of the analysis of averaging errors for conditioners based on buck-boost and Sepic topologies are presented. In this paper one can find averaging errors analysis both as a function of switching frequency as well as a function of load resistance.

An AC Voltage Transformation Circuits Based on Zeta or Sepic PWM AC Line Conditioners

Zbigniew Fedyczak, Ryszard Strzelecki, Adam Kempski
Technical University of Zielona Gَra, Poland
Institute of ElecTRICAL Engineering,
ul. Podgrna 50
65-246 Zielona Gra, Poland
tel.: (+48 68) 3282528,  fax: (+48 68) 3254615
e-mail:z.fedyczak@iep.pz.zgora.pl
r.strzelecki@iep.pz.zgora.pl
a.kempski@iep.pz.zgora.pl

Leszek Frąckowiak
Poznań University of Technology, Poland
Institute of Industrial Electrical Engineering
Piotrowo 3a
61-138 Poznań, Poland
e-mail: l.frackowiak@put.poznan.pl

This paper deals with matrix-reactance PWM AC line conditioners (MRACLCs) based on Zeta or Sepic converter topologies, which are well known from DC/DC converter applications. These conditioners have a capability to increase the AC load voltage above the AC line supplying voltage without an electromagnetic transformer. Furthermore, the phase of the load voltage is the same as the supplying one. The description of operation and steady-state basic energetic properties analysis of averaged models of these conditioners are presented. Four-terminal chain parameters of averaged models are employment to ones theoretical description. The theoretical analysis along with simulation and experimental test results, obtained for a 500 VA laboratory model of the presented MRACLCs, has been carried out for initial evaluation of their application suitability in direct AC/AC conversion circuits.

IGBT AUXILIARY CONVERTER INTEGRATED INTO A TRACTION CONVERTER

Sead Mesic, Markus Jِrg, Gernot Enzensberger
Adtranz (Switzerland) Ltd
P.O. Box
CH - 5300 Turgi
Tel. +41 56 299 37 10 / Fax. + 41 56 299 26 16
sead.mesic@ch.transport.bombardier.com

The subject of this paper is the description of a high power IGBT auxiliary converter (AXC) that is integrated into a traction converter with an intermediate d.c. voltage link. This paper will describe the application, the protection concept and the characteristics of the auxiliary converter.

A NEW CONCEPT OF A CONVERTER FOR DUAL SYSTEM TRAMS

Marek Kowalczewski, Wojciech Mysiński, Waldemar Zając
Technical University of Cracow
ul.Warszawska 24
31-155 Kraków, Poland
Tel. +48 12 628 26 98, fax +48 12 628 26 54
mysinski@usk.pk.edu.pl
pezajac@cyf-kr.edu.pl

Kraków Town Council is planning to extend the local tram network (600V DC) using the railway network. The main problem posed by this project is the need for a dual system tram car which can run both on railway track, using the electric railway power supply network (3000V DC) and on tram track, using the electric tram power supply network (600V DC). This paper presents a new concept of a converter for 3000V/600V DC dual system trams. The converter is based on a three phase DC step down converter. Some experimental and simulation results are discussed, too.

New Control Method for Current Converters

Vanja Ambrozic, David Nedeljkovic, Rastko Fiser
FACULTY OF ELECTRICAL ENGINEERING
Trzaska 25
Ljubljana, Slovenia
tel.: +386 1 4768286/fax: +386 1 4768487
vanjaa@fe.uni-lj.si
http://lrt2.fe.uni-lj.si

In this paper, two methods for current control of multiphase systems are proposed. They are similar to the synchronized on-off control, where phase currents (or the current space vector) are sampled and compared to the reference currents. Depending on the difference sign, a transistor that would decrease the error is switched on. Unlike with the latter method, in our approach the current at the end of the interval and the corresponding current error are predicted. In the first approach either null voltage vector or the vector pointing in approximately the same direction as the current error vector is selected, depending on which one gives the smaller error. In the second method, the switching time for an optimal voltage vector is calculated following a least square error equation.

Optimal Linear Quadratic Controller for Quasi-Resonant DC-DC Converters

J. M. Dores Costa

ENIDH, Radioelectronics Dpt.
Paço de Arcos

2780 Oeiras – Portugal

Telephone: +351214460010/Fax: +351214429546

dorescosta@enautica.pt

Optimal control techniques are used to design a linear quadratic regulator (LQR) for quasi-resonant (QR) switching DC-DC converters with voltage-mode control. The method presented in the paper is based on small-signal models that were obtained as an extension of the state-space averaging models of PWM converters. These models show that the LQR structure has some similarities with current-mode control, since they both introduce feedback paths for the inductor current and the output capacitor voltage. However, whereas the feedback gains of current-mode control are fixed, with the LQR these gains can be calculated in order to minimise a quadratic cost function. Moreover, it is possible to design the LQR and the power stage of the QR converter interactively. Small-signal models of the QR converters are reviewed and the optimal LQR for voltage-mode control is presented. The process was experimentally tested and results from a prototype of a 1 MHz buck QR-ZVS converter with a LQR are presented.

Advanced Converter Module for High Speed Maglev System TRANSRAPID

Helmer J., Henning U., Kamp P. G., Nothhaft J.

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 compact inverter module was developed and successfully equipped with 4.5kV IGBTs and 4.5kV hard driven GTOs respectively. The comparison between measurement and calculation shows that for high frequency application of the TRANSRAPID maglev system press-pack IGBTs or hard driven GTOs are more favorable than conventional GTOs.

A New Control Strategy for Flyback Converters

Radek Nalepa^{1), 2)}, Noel Barry^{2), 3)}, Peter Meaney<sup>1)

1)</sup> Artesyn Technologies,
Springfield Industrial Estate,
Youghal, Co. Cork,
Ireland
Tel: +353 24 93130
Fax: +353 24 93257
radek.nalepa@artesyn.com
peter.meaney@artesyn.com

²⁾ Department of Electronic Engineering, Cork Institute of Technology,
Rossa Avenue, Bishopstown,
Cork, Ireland
Tel: +353 21 4326384
Fax: . +353 21 4326625
rnalepa@cit.ie
nbarry@cit.ie

³⁾ Department of Electrical Engineering,
University of South Carolina,
USA
Tel:+1 803 7771488
barrym@engr.sc.edu

Galvanic isolation between the input and the output of the flyback switch-mode power supplies is required in many cases. The power stage is naturally isolated by the flyback transformer. And the feedback path is typically isolated by an opto-coupler. However the output voltage also exists  (in part) across the primary side switch in its off stage. This paper investigates the extraction of the output voltage during the off-time [6]. Results obtained from a flyback converter with a novel control circuit using cycle by cycle control are shown. The converter operates in both continuous and discontinuous conduction modes. An equivalent circuit for modeling and analysis of the primary and the secondary side oscillations is shown. 

Power conditioning method for SMES by use of ICB energy transfer circuit

Jumpei Babay, Tanzo Nittaz, Yasuyuki Shirai,Yukio
Faculity of Science and Technology
Science University of Tokyo
2641 Yamazaki, Noda-shi
Chiba, 278-8510, Japan
Tel. +81-471-24-1501 ext. 3767 , Fax. +81-471-24-1810
e-mail: baba@emasada.ee.noda.sut.ac.jp

Hayashiy and Yoshihiro Kobayashi
Department of Electrical Engineering
The University of Tokyo
7-3-1, Hongo, Bunkyo-ku
Tokyo, 113-8656, Japan
Department of Energy Science & Technology
Kyoto University
Yoshida Honmachi, Sakyo-ku
Kyoto, 606-8501, Japan

The paper describes a 6.6 kV, 8 MVA drive for an asynchronous motor running at 15,000 rpm. The drive is realized with a sixpulse GTO current source inverter on the motor side and a twelvepulse thyristor bridge on the line side. In the application the high speed motor is mounted gearless with a gas compressor on one shaft. To avoid lubrication magnetic bearings are used. The drive system has been applied to several natural gas pumping stations in the Netherlands and Germany.

Variable Output Bidirectional dc - dc Converter

Wieslaw E. Bury
Polytechnic University  -  Dept. of Electrical Eng.
6 Metrotech Center
Brooklyn, New York 11201  - USA
Tel. 718-260-3894  -  Fax. 718-260-3906
Email: web@zpower.poly.edu
http://www.poly.edu

Dariusz Czarkowski
Polytechnic University  -  Dept. of Electrical Eng.
6 Metrotech Center
Brooklyn, New York 11201  -  USA
Tel. 718-260-3256  -  Fax. 718-260-3906
Email: dcz@pl.poly.edu
http://www.poly.edu

A bidirectional dc–dc converter with output voltage tracking capabilities was designed and tested with a 110 Hz reference signal. A linear controller was designed in the frequency domain. Experimental results are in a good agreement with theoretical and simulated predictions. The converter is intended to drive piezoceramic actuators.

A Stochastic Inverter Model due to Switching Time Uncertainties

Anawach Sangswang                                     Chika O. Nwankpa
Center for Electric Power Engineering
Department of Electrical and Computer Engineering
Drexel University
Philadelphia, PA 19104  -  USA
Tel. 1-215-895-1466  -  Fax. 1-215-895-1561
anawach@cbis.ece.drexel.edu
chika@nwankpa.ece.drexel.edu
http://power.ece.drexel.edu

The performance of a pulse-width modulated (PWM) converter is analyzed as a result of switching time uncertainties. In the absence of control actions, random noises will force a system to leave its stability region in a finite time, even if the system is initially at its stable equilibrium point. From this aspect, the deterministic model of stability will no longer apply and the cumulative effect of small random perturbations on a dynamical system may be considerably different.  The cumulative effect of small random fluctuations on a system parameter can push the system operating point beyond a predefined boundary. A stochastic model of an inverter with practical uncertainties, which has not been addressed before, is pointed out. This stochastic model is based on the introduction of perturbations in the duty ratio of switching converters as random noise processes, which has been developed by the use of the theory of stochastic differential calculus. In this paper, random characteristics of the system parameters are modeled by a zero mean gaussian white noise, which is inherently associated with power electronic converters and represents the behavior of the system in a fluctuating environment. The singular perturbation technique is employed to transform the differential algebraic system into system differential equations with the help of a singular parameter. Commutation rise and fall times are quantified through the singularly perturbed parameter. A performance index, known as the mean first passage time (MFPT) is also determined. The MFPT of the stable state of the process is defined as the passage time of the process in a certain domain of attraction, averaged over all possible initial states. Effects of switching time uncertainties on the inverter system are compared between  the MFPT  and its deterministic counterpart, critical energy.

Power Domain of Three Phase PWM Rectifiers

Sergi Fillet Castella, Joan Bergas, Samuel Galceran, Antoni Sudria
CIT-CEA / UPC
Diagonal, 647
08028 Barcelona, Spain
Tel : +34 93 401 67 29 / Fax : +34 93 401 74 33
Sergi.Fillet@upc.es

The power domain of three-phase pulse width modulation voltage-source rectifiers (PWM-VSR) is not frequently taken into consideration. In this article, the active and reactive controllable domain for PWM-VSRs is derived when connected to ideal networks. Maintaining the rectifier in the presented controllable domain prevents their harmonic components of the currents on the main from increasing and prevents the system from losing stability. The circular domain limits are determined by its mains circuit parameters. The importance of DC-link voltage and input inductance is made evident. Influence of limits when network voltage varies is also taken into consideration, showing the limits of sags and undervoltages surpassing capacity.

Improved Forward Converter Integrated in a Modular DSP-driven Inverter

Fabrice FREBEL
CE+T S.A.
Rue du charbonnage, 18
B-4020 LIEGE, BELGIUM
Tel.: 00 32 4 345 67 39 / Fax.: 00 32 4 345 67 01
e-mail : f.frebel@cet.be
URL : http://www.cet.be

Paul BLEUS
CE+T S.A.
Rue du charbonnage, 18
B-4020 LIEGE, BELGIUM
Tel.: 00 32 4 345 67 40 / Fax.: 00 32 4 345 67 01
e-mail : p.bleus@cet.be
URL : http://www.cet.be

Hugues LIBOTTE
University of LIEGE
Dept. ELAP, Sart-Tilman
BELGIUM

Reliable AC back-up fed by a battery source are in a continuous evolution. The market's need drove us hard to develop a new topology of DC/DC converter integrated in a full digital control inverter. This new technical approach has been implemented over an inverter range. It has been done at first on a 2U'/1kVA unit and a 1U'/300VA unit both naturally cooled as well as a 3kVA unit forced air of 2 U'height, outputting 120 Vac or 230 Vac.
In the power inverter field, one of the best way to get the proper AC availability level is to increase the MTBF¹ of the unit. Well-known means to improve the MTBF are the decreasing of part-count number and a lower working temperature, actually the challenge is to get the higher possible efficiency.
A more than 90% overall efficiency has been achieved with a new isolated DC/DC converter called the "Symmetrical Flux Forward"(SFF), stepping up the input voltage from a low voltage to 350 Vdc. This improved topology has a very low part-count and many other advantages.
The low part-count condition has been fulfilled too by applying the most recent technologies in an inverter. In fact, digital signal processing (DSP) and field programmable gate array (FPGA) technologies become a possible and interesting solution to overcome the inverter control barrier.
Closing all control feedback loops in the digital signal processor gives us also a temperature dependency compensation of analog devices, a very low part count, an efficient active filtering to comply with standard and an automatic board self-checking at the manufacturing time.
This paper presents the state of the art in the inverter technology and a new DC/DC converter topology leading to a smart AC inverter solution.

Three-Phase Current-Source-Type PWM PFC Rectifier

Yasuyuki Nishida, Takeshi Kondoh
Nihon University
Tokusada, Tamura
Kouriyama, 963-8642, JAPAN
Tel. & Fax. +81-24-956-8788
e-mail:nishida@ee.ce.nihon-u.ac.jp

Mutsuo Ishikawa, Kiyoto Yasui
Niwa Electric Co. Ltd., JAPAN
138, Sakanoshita
Tokorozawa, 359-0012 JAPAN
Tel. +81-42-945-4571, Fax. +81-42-944-9519
e-mail:mishikawa@niwadenki.co.jp

A new 3-phase current-source-type (or buck-mode) PWM PFC rectifier is proposed. The necessity, the advantages and disadvantages of this type PWM rectifier are discussed first. Then, the new power circuit topology and the modulation scheme to eliminate or mitigate the disadvantages and obtain further new advantages of the current-source-type PWM rectifier are introduced. The features of the new rectifier, i.e., high efficiency, simple modulation process, robustness of the line-current modulation against dc current ripples caused by distortion and asymmetrically of the utility voltages have been confirmed through experimental results obtained from a prototype 12[kW] rectifier.

Parallel Operation of  DC/AC Master-Slave Inverters Using Sliding Mode Control

Miret Tomas, J. Student Member IEEE, Garcia de Vicuña Muñoz de la Nava, J.L. Member IEEE, Lopez Garcia, M. Student Member IEEE.
UNIVERSITAT POLITECNICA DE CATALUNYA,
Avinguda Victor Balaguer S/N,
Vilanova i la Geltru, 08800, Spain
Tel.: 34 93 896 77 28
jmiret@eel.upc.es
vicuna@eel.upc.es

In this paper we present a sliding mode control scheme for parallel operation of DC/AC converters. The sliding surfaces proposed, endows linear behaviour dynamics in the output voltage. This kind of control provides high robustness in the output voltage against step changes in the load and in the input voltage.

Power conditioning method for SMES by use of ICB energy transfer circuit

Jumpei Babay, Tanzo Nittaz, Yasuyuki Shirai,
Faculity of Science and Technology
Science University of Tokyo
2641 Yamazaki, Noda-shi
Chiba, 278-8510, Japan
Tel. +81-471-24-1501 ext. 3767 , Fax. +81-471-24-1810
e-mail: baba@emasada.ee.noda.sut.ac.jp

Yukio Hayashiy and Yoshihiro Kobayashi
Department of Electrical Engineering
The University of Tokyo
7-3-1, Hongo, Bunkyo-ku
Tokyo, 113-8656, Japan
Department of Energy Science & Technology
Kyoto University
Yoshida Honmachi, Sakyo-ku, Kyoto, 606-8501, Japan

Inverter-Converter Bridge (ICB) energy transfer circuit consists of two power converters and the capacitor bank. Each of two superconducting magnets are connected to each of two power converters and the stored energy is transfered by use of the circuit. The circuit has been mainly studied as an exciter circuit for pulse superconducting magnets because it enables to excite the large magnet quickly without a_ecting the power systems. It is easy to construct the required large capacity because the circuit can be made for natural commutation thyristors.
The circuit, which is connected to power system through the converter (utility tie converter), has attractive features for SMES power converter, for instance, wide control region of active and reactive power without forced commutative power devices. The relation between utility tie converter control and the ICB circuit control is important for realizing SMES converter system.
In this paper, the power conditioning method of ICB energy transfer circuit has been discussed to adopt ICB energy transfer circuit as power supply for SMES. The theoretical analysis and the experimental results are shown.

Implementation of Direct Torque Control of Induction Motor Drive using Four Switch Three Phase Inverter

A. L. Orille Mohamed Azab
Politechnical University of Catalonia Banha High Institute of Technology                       
Department of Electrical Engineering Department of Electrical Engineering
Avda. Diagonal, 647                        
Banha El Gadida, Banha 
E-08028 Barcelona-Spain
E-13512 Banha-Kalubia-Egypt                                                                  
Tel. +34 93 401 1982    Fax. +34 93 4017433
Tel. +34 93 739 8156     Fax. +34 93 739 8236
orille@ee.upc.es mazab@ee.upc.es
pe_group@hotmail.com                                      

This paper presents a new method to generate PWM signals to control the Four-Switch 3-Phase Inverter (FSTPI). The method is based on direct flux and torque control, which is usually implemented based on the classical six-switch inverter (SSTPI) but has not been applied with the topology FSTPI before. A new switching table has been derived, which selects the optimum inverter switching states to fulfil the torque and flux requirements. The proposed DTC system provides quick response and accurate control of both stator flux and motor torque. Experimental results have verified the validity and effectiveness of the proposed system to obtain a high performance AC drive with reduced cost suitable for low power range. Therefore the FSTPI topology can be an alternative to the classical six-switch topology for low power AC drives.

A Novel PWM Controlled AC-Chopper Circuit Based on DC-Clamped Bilateral Switching Circuit Topology and Its Typical Applications

Yasuhiro Okuma, Hiroshi Yamamoto, Yoshihiro Shoji
Power Electronics Laboratory
Fuji Electric Corporate Research and Development, Ltd.
1, Fuji-machi, Hino-city
Tokyo 191-8502, Japan
Phone: +81-42—586-1104/ Fax: +81-42-586-9665
E-mail: okuma-yasuhiro@fujielectric.co.jp

Conventional AC-chopper circuits using bi-directional switches can be used to control ac power. These bi-directional switches are generally anti-series connected self-commutative switches.  As a result, there are problems regarding the main circuit configuration and snubber circuit, among others, and few AC-chopper circuits have been used in practice.
Then, we authors proposed a novel PWM controlled AC-chopper circuit based on dc-clamped bilateral switching circuit topology.  And an ac power supplies using a PWM controlled AC-chopper circuits was commercialized.
First, this paper outlines the problems of conventional AC-chopper circuits.  It then proposes a PWM controlled ac power supply, which is a novel AC-chopper circuit topology, and describes its principle of operation.  Furthermore, an ac voltage regulator and a series voltage-compensated ac voltage regulator are introduced as typical applications of the proposed AC-chopper circuit.

DS2.5: Topic 5: Modulation strategies and specific control methods for static converters I
(J. Peracaula, UPC, Spain)

Frequency Domain Analysis of Space-Vector PWM Four-Switch Voltage Source Inverter

J.Klima
TECHNICAL FACULTY OF CZU, PRAGUE
165 21 Prague6-Suchdol
Czech Republic
Tel: +420 2 2438 3203 . Fax:+420 2 2092  1361
E-mail:KLIMA@TF.CZU.CZ

The paper presents harmonic analysis of the space vector PWM waveform of the four-switch voltage source inverter feeding an induction motor drive.The analysis is based on a novel decomposition technique and on the Laplace transform of the voltage space vectors.As the phase voltages are in principle asymmetrical,first the asymmetrical space vector sequence is expressed in symmetrical form.It is shown that the asymmetrical space vector sequence can be expressed with two symmetrical sequences.First sequence has vectors that are mutually shifted by 600 as in conventional inverter,and second sequence has vectors shifted by 1800 and amplitudes are one half of the first sequence.Then the Laplace transform of the symmetrical space vector sequence is expressed.Using the relation between the Laplace transform of the periodic waveform and Fourier coefficients we can find the coefficients of the Fourier series.From the analytical relations we can derive harmonic spectra for different  space vector modulation technique.

A Fully Digital PWM for Highest Precision Power Supplies

Felix Jenni, Martin Emmenegger
Paul Scherrer Institute
CH 5232 Villigen PSI
Switzerland
Tel: 0041 56 310 3117; Fax: 0041 56 310 3717
Email: felix.jenni@psi.ch
martin.emmenegger@psi.ch

The width of fully digitally generated Pulse Width Modulator (PWM) signals can be varied in discrete time steps only. In closed loop systems this limited resolution leads to limit cycles. With the multiple combination of PWM and a special pulse frequency modulation the output values of high precision power supplies (PS) are controlled down to zero with a very high resolution.

Methods Reducing Distortions on Output Current and Voltage Waveforms in PWM Voltage Source Inverters

Dipl.-Ing. Frank Herty
UNIVERSITY OF KAISERSLAUTERN
Department of Electrical Engineering and Information Technology
Institute of Power Electronics and Electronics
Erwin-Schrِödinger-Straße 67663 Kaiserslautern
Tel: +49-631-205-3124 / Fax: -2612
herty@rhrk.uni-kl.de

This paper presents six methods improving the output current waveform of a PWM voltage source inverter. Due to several delays and other effects during a switch over process of a half bridge typical delay errors can be seen which are not in context to the modulation strategy. Considering drive systems designed for low torque ripple or high speed it is definitely not sufficient using an optimised modulating strategy only. In contrast to the decreased load current harmonics the delay errors are coming more and more into effect when the switching frequency is increased.
First, the reasons of the delay errors are examined. Then follows a short description of methods which are capable to compensate or correct an individual subset of this errors. If possible, all effects are explained using the space vector theory.

Generation of 3 - Phase Voltage using Space Vector Modulation Method

Algirdas Baskys, Vitold Gobis
Semiconductor Physics Institute
Gostauto 11
Vilnius, Lithuania
Tel: +370-2-613989 / Fax: +370-2-627123
e-mail: mel@uj.pfi.lt
URL: http://www.pfi.lt

The five methods of three-phase voltage generation for frequency converters of AC motor drives are analyzed. They are based on the same principles and allows to reach the same maximum output voltage as conventional SVPWM (Space Vector Pulse Width Modulation) method, but are differing in requirements for inverter switches dynamic characteristics, in keeping of control unit busy with voltage generation and in quality of generated voltage spectrum.

New method to calculate the conduction durations of the switches in a n-leg  2-level Voltage Source Inverter

Semail E., Rombaut C.
LABORATOIRE D'ELECTROTECHNIQUE ET D'ELECTRONIQUE DE PUISSANCE DE LILLE (L2EP)
USTL Bat P2 UFR IEEA,
 59655  VILLENEUVE D’ASCQ CEDEX - FRANCE
Phone : 33 3 20 43 41 57 / Fax : 33 3 20 43.69.67
URL: http://www.univ-lille1.fr/l2ep/
E-mail : eric.semail@univ-lille1.fr

The proposed method allows to calculate explicitly, using mathematical notions of barycenter and mixed product, the conduction duration switches of a n-leg 2-level Voltage Source Inverter (VSI) supplying a n-wire load. This method depends on a new geometrical and vectorial VSI characterization. Its geometrical feature enables optimization and graphic representation such as the Space Vector Method (SVM) for a 3-leg VSI.  Its  vectorial feature enables to generalize to n phase systems the properties found out with three phase systems.

Variable  Structure  Control  for  imbricated cells Multi-levels inverter Fed Induction Motor Drives

Faouzi BEN AMMAR
INSAT : Centre Urbain  Nord BP N°676 1080 Tunis
Tel 216 1 703.829 Poste 6437
Fax :216  1 704.329 Cedex.
Email: Faouzi.Benamar@insat.rnu.tn
L.S.E : Laboratoire des Systèmes Electriques
ENIT  BP 37-1002 Tunis le Belvèdère

The paper presents the study of Variable Structure Controller of the series multicell voltage source inverter feeding a high power squirrel-cage induction motor. An appropriate multilevel switching table  has been developed to achieve fast torque response and to give a floating capacitor voltage distribution balanced and stable with an optimised output waveform.

NEW OPTIMAL METHODS FOR PWM INVERTER DEAD-TIME COMPENSATION

Lazhar BEN-BRAHIM
University of Qatar
Doha, Qatar
e-mail: brahim@qu.edu.qa

To prevent the phase shortage of inverter arms, a time delay is inserted between the switches of the same arm. This lag-time causes serious distortions of the output voltage of the inverter. The lag-time is well known as dead-time effect. Conventional dead-time compensation methods based on current reference polarity, are widely used to improve the output current waveforms. The improved waveforms however still suffer from the zero current crossing phenomenon. This paper analyses the origins of waveforms distortions around the zero current crossing in PWM (Pulse Width Modulated) inverters. The conventional compensation methods as well as a three proposed methods to reduce the distortions in the PWM inverters output waveforms caused by the dead-time and the zero crossing problem are highlighted. Theoretical analysis as well as simulation results to verify the proposed methods are described in this paper.

Robust Matrix Converter Commutation without explicit Sign Measurement

Jochen Mahlein, Jens Igney, Michael Braun
Elektrotechnisches Institut
Universität Karlsruhe
Kaiserstr. 12
D-76128 Karlsruhe, Germany
mahlein@eti.etec.uni-karlsruhe.de
igney@eti.etec.uni-karlsruhe.de
braun@eti.etec.uni-karlsruhe.de

Olaf Simon
Siemens AG
A&D SD E6
Frauenauracher Str. 80
D-91056 Erlangen
Olaf.Simon@erlf.siemens.de

A new operation method for matrix converters is presented which eliminates the extra measuring circuits of voltage or current signs that were necessary for the commutation in the past. The paper explains the new robust method that minimises switching losses. Advantages and disadvantages of different approaches are discussed and measurements on a 5.5 kW matrix converter system are shown.

Predictive Middle Point Modulation: A New Modulation Method for Parallel Active Filters

Manuel A. Perales, Juan M. Carrasco, Juan A. Sánchez, Luis Terrón, Leopoldo García Franquelo.
DEPT. OF ELECTRONIC ENGINEERING. UNIVERSITY OF SEVILLE
Escuela Superior de Ingenieros. Camino de los Descubrimientos
Isla de la Cartuja.
Seville, Spain
tel: 954 48 73 74. fax:  954 48 73 73
e-mail: perales@gte.esi.us.es
            carrasco@gte.esi.us.es
            shanshe@gte.esi.us.es
            syl@gte.esi.us.es
            leopoldo@gte.esi.us.es

When designing an Active filter, using a current-controlled voltage source inverter, there are two main tasks : to generate an appropiate reference, for nulling harmonic current and reactive power,  ant, on the other side, to generate a  switching pattern that permits to follow the reference as close as it can be done. Predictive Middle Point Modulation (PMPM) is a novel modulation technique, specially suited for Active Filters. This method is derived from predictive Dead-Beat controller, improving its dynamic response and current error. Simulation results confirm the validity of the proposed method. Experimental results will be provided in the final paper.