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 a proprietary model to calculate magnetic stability for our hydropower generators.

Objective

The objective of this thesis is to develop a model to calculate magnetic stability for a hydropower 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.