Master's Thesis - Dynamic Line Rating based on phasor measurements HT25

Vattenfall Eldistribution AB is Sweden’s largest Distribution System Operator (DSO), managing around 9,000 km of 130 kV overhead lines. We face challenges in increasing electric power transmission, as power lines are currently rated based on static summer or winter conditions. Building new lines is expensive and often controversial.

For several years, we’ve used Dynamic Line Rating (DLR) based on weather measurements to increase capacity on some lines. However, this approach is difficult to scale for larger volumes. Therefore, Vattenfall Eldistribution is exploring an innovative solution: DLR using phasor measurements. This technology uses synchronized voltage and current measurements at the ends of power lines to calculate real-time power loss and line temperature, enabling dynamic ratings based on local weather conditions.

Scope 

This Master Thesis aims to clarify the mathematical foundations of DLR based on phasor measurements. The first step is to describe some commercial products using this method, and summarize international experiences in the field. The second step assesses the equations, including conditions, limitations and expected inaccuracies. Finally, a thorough assessment of the measurement chain is conducted, including a sensitivity analysis. How will measurement transformer inaccuracies or failing time synchronization affect the result? How accurately can the power lines (temperature dependent) resistance be expressed? What is the overall assessment of DLR based on phasor measurements?

• Key question: How accurately can an overhead line medium temperature be calculated?
• Limitations: 130 kV overhead lines only

At Vattenfall, we are determined to enable fossil freedom. To succeed, we must first become fully fossil-free ourselves as one of Europe’s largest energy companies. But that is not enough. To contribute to a fossil-free society, we need to do more than just focus on sustainable energy production.

We believe that enabling fossil freedom requires us to address the challenge from a broader perspective than merely producing energy sustainably.

To enable the fossil freedom that drives society forward – this is our purpose. We are looking for talented students who want to help us on our journey towards fossil freedom. By writing a thesis at Vattenfall, you will have a unique opportunity to contribute to our purpose.

Join us on the journey towards fossil freedom! 

We are looking for a student or students who want to work toward fossil-free living and are soon graduating from their academic studies. You are also someone who identifies with our principles: Active, Open, Positive, and Safety-focused.

• Education: Enrolled in a master’s program in Technical Mathematics, Electric Power, or Theoretical Physics
• Availability: Open to 1 or 2 master’s students
• Language Request: Ability to present in Swedish at our Trollhättan office

• Duration: Sep -Dec 2025 (start date as agreed)
• Location: Gothenburg
• Application: A single file with CV and grades.
• Last date for application: 2025-06-30
• Contact at Vattenfall: Tor Johansson, tor1.johansson@vattenfall.com, 0730-856 407

Diversity and Inclusion – In Everything We Do

We are convinced that heterogeneous teams can outperform homogeneous ones. But we can only unlock the power of diversity when everyone feels included. Read more about our important work on diversity and inclusion at https://careers.vattenfall.com/se/sv/jobba-med-oss/mangfald-inkludering.