Doctoral student in Industrial Electrical Engineering with focus on high voltage systems in electric vehicles - Hiring in process/Finished, not possible to apply

Industrial Electrical Engineering and Automation Division (IEA) is looking for a motivated candidate who is willing to make a difference in the fight against global warming and push for accelerating the electrification of road transport.

Description of the workplace

The doctoral student will be employed at the Industrial Electrical Engineering and Automation Division (IEA). The research at IEA is focused on the thematic areas of electric power systems, electric drive systems and water systems. All research aims at a sustainable society in line with the EU climate goals and the UN 2030 Agenda for Sustainable Development. Specifically, scientific methods for modelling, analysis and control of systems of industrially relevant complexity are applied and validation is based on laboratory analysis and field measurements. 

Subject description 

The research education subject is industrial electrical engineering. The Industrial Electrical Engineering research group focuses on technologies and systems for electrical and electromechanical energy conversion, with a special focus on the electrification of different types of vehicles. The subject is inherently interdisciplinary with strong links to electromagnetism, power electronics and electronics, materials engineering, electrical machine design, control engineering, as well as realtime systems, industrial automation and electrical metrology. The subject also links to industrial automation where research problems at a more global system level are addressed. Research in industrial electrical engineering is often inspired by real industrial problems. 

Project

The tasks are based on a need for more knowledge about the design considerations that must be made when the voltage of electric vehicle traction systems is increased. Today, this voltage is 350-400 V in passenger cars and 600-800 V in heavy vehicles, with few exceptions. It is known that some car manufacturers have already converted to 800 V solutions and that heavy vehicles might need to reach 1250 V to take advantage of the charging infrastructure of the future. 

Increased voltage in the traction system increases the demands on the battery (BMU needs a higher isolation voltage, more cells in series need more voltage sensors, more computational capability), the power electronic motor drive needs semiconductors for higher voltage rating or a change in topology, the EMI situation is aggravated with higher voltage derivative, the isolation requirements of all equipment connected to the drive system voltage needs to increase. 

There are also several ways to limit the impact of increased voltage. The power electronic drive can switch more slowly (reducing EMI but increasing losses) and/or be a multilevel converter. Filters can be inserted between the converter and the traction motor. The winding insulation of the traction machine can be reinforced to withstand higher voltage and voltage derivatives, but this can potentially cause thermal disadvantages. 

The aim of the PhD project is to model the main consequences of the increased voltage and the corresponding design changes from a cost, performance (weight, efficiency, ...) point of view and to provide decision support to automotive companies. The division of Industrial Electrical Engineering and Automation is therefore seeking a PhD student with a focus on modelling and simulation of the vehicle high voltage system, including the traction battery, the power electronic drive and the traction machine (electric machine) as well as experimental characterization and validation of key subsystems needed to support the modelling work. The PhD candidate will work in direct project collaboration with AB Volvo, BorgWarner, Volvo Cars and Alstom.

Work duties                     

The main duties of doctoral students are to devote themselves to their research studies which includes participating in research projects and third cycle courses. The work duties will also include teaching and other departmental duties (no more than 20%).

The work will be carried out in a group with other doctoral students and senior researchers within the same or closely related topics.

Admission requirements

To meet the general admission requirements for third-cycle courses and study programmes the applicant must:

• has been awarded a second-cycle qualification, or
• has satisfied the requirements for courses comprising at least 240 credits of which at least 60 credits were awarded in the second cycle, or
• has acquired substantially equivalent knowledge in some other way in Sweden or abroad

A person meets the specific admission requirements for third-cycle studies in industrial electrical engineering if the applicant has: 

• at least 30 second-cycle credits of relevance to the field of study

Additional requirements

• Very good oral and written proficiency in English

Assessment criteria

Selection for third-cycle studies is based on the applicant’s potential to successfully complete such studies. The assessment of potential is made primarily on the basis of academic results from the first and second cycle. Special attention is paid to the following:

1. Knowledge and skills relevant to the thesis project and the subject of study.
2. An assesment of ability to work independently and to formulate and tackle research problems.
3. Written and oral communication skills.
4. Other experience relevant to the third-cycle studies, e.g. professional experience.

Other assessment criteria

• Good knowledge in power electronics, electric circuit and electrical machines modelling.
• Experience working in a high voltage laboratory.
• Experience of working with modelling and construction of electric vehicle traction systems.
• The appropriate background for applicants is an MSc in Engineering Physics or Electrical Engineering with a clear focus on one or more of the fields of electric vehicles, power electronics and electrical machine technology.

Special consideration will also be given to excellent collaborative skills, drive and independence, and how the applicant, through experience and skills, is deemed to have the abilities necessary for successfully completing the third cycle programme. 

Terms of employment

Only those admitted to third cycle studies may be appointed to a doctoral studentship. Third cycle studies at LTH consist of full-time studies for 4 years. If the student is involved in teaching and other departmental duties, the appointment will be extended accordingly, although to a maximum of 5 years (i.e. max 20% departmental duties). Doctoral studentships are regulated in the Higher Education Ordinance (1993:100), chapter 5, 1-7 §.

Instructions on how to apply

Applications shall be written in English and include a cover letter stating the reasons why you are interested in the position and in what way the research project corresponds to your interests and educational background. The application must also contain a CV, degree certificate or equivalent, and other documents you wish to be considered (grade transcripts, contact information for your references, letters of recommendation, etc.).

You are also asked to answer the selection questions.