Company description

We at Vattenfall are committed to making fossil-free living possible. To succeed, as one of Europe's largest energy companies, we must first become completely fossil-free ourselves. But that is not enough. To contribute to a fossil-free society, we need to do more than just focus on sustainable energy production.

Because we are convinced that if we are to make fossil-free living possible, we need to look at the challenge from a broader perspective than just producing energy in a sustainable way.

Join us on the road to fossil-free living.

About the role

Power Climate Smarter living - that's our purpose. We are looking for talented students to help us on our journey towards fossil-free living. Writing a thesis at Vattenfall gives you a unique opportunity to contribute to our purpose. All we ask is that you unleash your superpowers and share your energy with us.

Background

Hydro power has a relatively small climate impact and accounts for almost half of Sweden's electricity production. Vattenfall owns and operates about 125 large-scale hydropower units, most of which have a vertical shaft supported by plain bearings, this together with the low operating speed and large magnetic forces between rotor and stator in the generator distinguishes hydropower units from other large rotating machines. Hydroelectric generators have very large masses combined with small air gaps between the rotating and stationary parts.

Magnetic stability is one of the parameters evaluated when renewing and purchasing generators. It is defined as the displacement of the rotor that can be tolerated before the magnetic attraction force exceeds the stiffness of the bearings and support structure, leading to instability and collapse between rotor and stator. Today, this criterion is evaluated differently by different generator suppliers, there is a varying degree of complexity in the models and how the properties of different components are taken into account.

Vattenfall R&D wishes to develop its own model to calculate magnetic stability for our hydropower generators.

Objective

The objective of this thesis is to develop a model to calculate the magnetic stability of a hydroelectric generator.

• Identify the appropriate level of model complexity.
• Identify the necessary inputs and desirable outputs.
• Identify which component properties need to be included.
• Develop model to calculate magnetic stability.
• Ev. comparison with other models.

Suggested work steps

• Literature study with focus on:
• Hydroelectric generators
• General theory of rotor dynamics
• General theory of hydrodynamic sliding bearings
• General theory of magnetic attraction
• Planning and structuring of the work.
• Discussions (e.g. interviews) with Vattenfall's experts in the field.
• Mapping of suitable modeling methods, necessary input data and suitable output data as well as which components and properties should be included.
• Programming of model, for example in MATLAB or FEM software.
• Report writing and presentation of the work.

Requirements specification

We are looking for student(s) who want to work towards a fossil-free future and who will soon graduate from your academic studies. You are also someone who identifies with our principles: Active, Open, Positive and Safety

• Education - Master student in Mechanical Engineering, Engineering Physics or similar.
• Very good knowledge of Swedish and English

Additional information

• The assignment starts: 2025-01-13 or by agreement
• Location: Luleå University of Technology or Vattenfall's office in Älvkarleby.
• Application - a file with your CV and a copy of your grades.
• Last day to apply is 2024-12-08
• Contact person and supervisor at Vattenfall: Rolf Gustavsson, rolf.gustavsson@vattenfall.com, 072 205 27 37 and Jens Österud, jens.oesterud@vattenfall.com, 070 306 97 62

Diversity and inclusion - in everything we do

We are convinced that heterogeneous teams can outperform homogeneous teams. But we can only unleash and use the power of diversity when everyone feels included.