EPE Association & Swiss Federal Institute of Technology

8th European Conference on Power Electronics and Applications


WORKSHOPS


Some workshops will issue a written report of the discussions. The final programme will be available on site.


Tuesday 7 september
Wednesday 8 September
Thursday 9 September

Back to main page


 

Tuesday 7 september

 

Evolution of Fast Power Diodes – J. M. Peter

A lot of progresses have been done in the field of active components, MOSFETs, IGBTs, IGCTs, but, the fast diode manufacturing is always the result of a trade-off between several parameters. Some improvements have been done in the last years, but no real progresses.

What kind of progresses or improvements could be expected? What method to improve the converter circuits? What perspectives with new materials, AS Ga and SiC: laboratory samples or devices in the field in the coming years?

 

Multilevel inverters: Which topology is the best? 3-, 5-, 7-, or n-level-inverter? Floating capacitors or NPC-topology? – M. Braun

Several types of high-power inverters are in industrial use: 2- and 3-level- inverter with IGBT and GTO partially in series and parallel connection, and the floating capacitor multilevel inverter. In scientific publications the number of levels is further increasing.

The participants of the workshop shall discuss the question, if an optimal solution exists concerning the number of levels and the circuit scheme.

 

Trends in monolithic power integration – J. Milan, J.-L. Sanchez

Trends in smart power and functional integration for applications up to few KW. Evolution in design and technology.

 

Modelling and Simulation in the Field of Power Electronics: Suggestions for Improvements – Johann W. Kolar

Topics : Modelling of Active Components/Passive Compoents, Combination of FEM Analysis and Circuit-Oriented Simulation, Simulation Tools Available, Simulation in Connection with Education, etc.

 

The future of AC machine sensorless control - industrially viable approaches, problems and markets, M. Schroedl, E. Levi

The session is planned as a review of the state-of-the-art and future directions in sensorless control techniques for induction motors, permanent magnet synchronous motors and other types of AC motors. Various methods, including those applicable for standstill operation, are discussed. During the last decade numerous methods for speed estimation in AC machines have been developed. They can be broadly classified into four different approaches.

The first approach is based on evaluation of reluctance and saliency effects and can be used at arbitrary speed including standstill (INFORM method and related approaches). The basic idea is to measure inductance parameters in different space directions.

The second approach can be used beyond a certain minimum speed. It relies on the use of a machine model and includes a variety of techniques (open-loop speed estimators, MRAC based speed estimation, observers and EKFs). Elaborate techniques for spectrum analysis are not required. However, accuracy of speed estimation is adversely affected by parameter variation effects.

The third group of methods extracts speed information from the current spectrum. These methods are inherently independent of parameter variation effects and require on-line application of a suitable method for spectrum analysis.    

The fourth, emerging, approach to speed estimation is based on artificial neural networks.

The purpose of this round table discussion is twofold. An overview of possible sensorless control strategies, their advantages and disadvantages, and practical experiences and recommendations about possible fields of applications will be provided first. Next, an attempt will be made to try to establish which approaches and methods are likely to prevail in the future and, most importantly, which methods are likely to be adopted by the drive manufacturers for the 21st century market.

Back to worksops menu

Back to time table

 

Wednesday 8 September

 

High Voltage MOSFET vs IGBT – H. Kabza

The workshop will discuss the challenge for the IGBT that may result from the very interesting electrical characteristics of the new MOS devices. The question of technical advantages of both technologies as well as that of cost and system benefits will be addressed.

 

Power Electronics and Microelectronic Control in Future Energy Systems, organised by M. Crappe and W. Leonhard

Statements by the members of the panel

General discussion

 

Connections for Power Electronics – J. Roudet and A. Rufer

Overview of different problems involved by parasitic inductance in power electronics (over-voltage, good current sharing in parallel semiconductors components, decoupling capacitors, ...)

How to improve power connections ?

How to characterise power connections?

How to measure power connections ?

 

Matrix converter: the power-converter of the future? – M. Braun

The Matrix-converter doesnt need any intermediate link and is able to control the input power factor from the capacitive to the inductive range. Using a sufficiently high pulse frequency, the output voltage and input current both are shaped sinusoidally. In spite of these advantages no industrial use has been made of this converter type up to now.

The participants of the workshop shall discuss, if there are hidden risks in this converter type or if the matrix converter will replace the voltage-fed PWM-inverter in the near future.

Back to worksops menu

Back to time table

 

Thursday 9 September

 

High Power IGBTs and Power Module reliability – J. M. Peter

Press pack packages or Modules? Two tendencies in the field. Some years ago, the module reliability against thermal fatigue was, according to the tests made in specialised labs, very poor. Despite this weakness, a lot of equipment manufacturers have had good results in the field. What is the concrete experience from motor drive manufacturers this last years about this reliability? What are the progresses done in the field of power modules? Improved bondings and DCB? Pressure contacts? What about the press pack IGBTs in the field? Influence of the packaging in case of accident?

 

Education, organized by T. Undeland and N. Mohan

Panelists: Tore Undeland, Ned Mohan, Franco Profumo and Javier Uceda.

On the Session we will discuss teaching of power electronics with emphasis on laboratory experiments (Ned Mohan), tools like CD-ROM and WWW (Franco Profumo) and how to teach design of inductors and transformers for Switch Mode Power Supplies (Tore Undeland and Javier Uceda). We will also discuss completely new ways of teaching:

1) a First Course on Electric Drives (without any prerequisite of electric machine theory)

2) a First Course on Power Electronics.

 

Power Factor Correction: Technical and Economical Points of View – Johann W. Kolar

Topics : Limits on THD (Harmonics) or Power Factor, Single-Stage or Two-Stage Topologies, Central Active Filtering versus PFC - Advantages and Drawbacks concerning Costs and Total Efficiency, etc.

Back to worksops menu

Back to time table

 


Number of hits:64 (since January 12th, 1998)
Mail to Local Organisation Committee: epe99@epfl.ch
Copyright © 1998, EPFL. All rights reserved.
Last update: Wednesday, 16-Jun-99 17:04:36 MET DST