PhD Fellowships in Adjustable Speed Drives, Aalborg University
Denmark. Three years PhD fellowships are available within a research project entitled with “ The use of active elements to reduce the size and weight of passive components in adjustable speed drives”. This is a research in the general study programme Electrical and Electronic Engineering. The project will be undertaken at Department of Energy Technology, Faculties of Engineering, Science and Medicine.
Interested candidates are expected to hold a Masters degree in Electrical Engineering and should have a sound background in magnetic components, semiconductor devices and control theory applied to power converters. Good simulation skills and a sharp interest in practical investigation are also required. Also experience of EMI filters, grid modelling and standards are important.
Furthermore, excellent written and oral communication skills are required. A non native English speaker must have a verified IELTS score report with a minimum score of 6.5 (or equivalent test) or be able to speak fluent Danish.
Successful candidate will be enrolled as a PhD student at the Doctoral School of the Faculty. The progress of the PhD student will be assessed every six months. It is a prerequisite for continuation of salary payment that the previous progress is approved at the time of the evaluation.
Project Description
Continuous evolution of power semiconductors and control circuitry makes the Adjustable Speed Drives (ASDs) of today efficient, reliable and cost effective and they play a significant role in many applications. However, the passive components used in ASD’s are increasingly contributing to both cost and size of the ASD.
This is due to the fact that fundamental electromagnetic laws govern the design of passive components. Power semiconductors and control circuitry, on the other hand, benefit heavily from the development in semiconductor technology. Looking into the future, the cost of passive components is likely to increase. Passive components are mainly made of iron, copper and aluminium which all are raw materials with a growing demand. The price of semiconductor devices has fallen in recent years.
Semiconductors will still follow Moore’s law in the foreseeable future and a further price reduction is therefore likely. Present day standard ASD solutions still have unsolved utility interface issues. Input currents have a high THD, are sensitive to voltage unbalance, and inrush protection can be complicated in combination with voltage dips.
This project shall investigate solutions for reducing the size/volume and cost of passive components in integrated ASD’s in the 5-20kW range. The main focus for these solutions should be to use power electronics combined with advanced control strategies in order to obtain excellent performance. The project investigations should include but not be limited to the following key topics: Resonance problems in small dc-link solutions (active damping or emulating large inductor), mitigation of grid harmonics, protection against grid disturbances, performance during unbalanced grid voltage and ride through capability.
As PhD student you will be member of a research team including the leading industrial manufacturer Grundfos and a high level university research environment with state of the art laboratory equipment. Close cooperation between the PhD student and senior researches as well as knowledge exchange with the industrial partner will be expected. The PhD candidate is expected to participate in international conferences as author.
You may obtain further information from Senior Development Engineer Henrik Kragh, e-mail: hkragh@grundfos.com, phone +45 87504880 or Associate Professor Stig Munk-Nielsen, e-mail: smn@iet.aau.dk, phone: +45 9940 9242.
The PhD application form can be downloaded from the following address:
http://adm.aau.dk/fak-tekn/phd/vacant/index.htm
Application is to be forwarded to :
Aalborg Universitet
De Ingeniør-, Natur- og Sundhedsvidenskabelige Fakulteter
Niels Jernes Vej 10
DK-9220 Aalborg Øst
For further information about stipends and salary contact Ms. Helen Kjerstein Kristensen, The Faculties of Engineering, Science and Medicine, email: hek@adm.aau.dk, phone: +45 9940 7373.
Application should include in four copies: the Masters diploma, publications, Curriculum Vitae, proposal for a PhD study plan and any other material, as well as a list of submitted material. Due to legal constraints electronic applications will not be accepted. Please quote the position reference No.HEK- 562/06-14-28048
Application deadline is the 02 June 2008.
