A Novel Health Monitoring System for Synchronous Generators using Magnetic Signatures

2022, Hossein Ehya, PhD

In his doctoral work, Hossein has found a cheap and effective method to detect faults in electric motors before they have occurred! The method involves listening to the engine's magnetic field to pick up irregularities that often occur before the accident itself. The method was developed for hydropower generators but has transfer value to other electric motors.

See a webinar on the results here.

Erosion in Francis turbines due to geometrical positioning of runner and guide vanes

2022, Nirmal Acharya, PhD

Through his work, Nirmal has looked at problems surrounding the wear and tear of turbine components due to sediments in the water. Through case studies and the use of numerical analyses, he has looked at how sediment-filled water moves through the turbine, and where and under which conditions the wear on the turbine components is greatest.

Remotely sensed data for bathymetric mapping and ecohydraulics modelling in rivers

2022, Håkon Sundt, PhD

Through his PhD, Håkon Sundt has looked at the use of remote sensing as a source of information on bathymetry, seasonal mesohabitats for fish, scenarios for mitigation measures and strategies for environmental eDNA sampling.

See a webinar on the results here.

Decision analytics in hydropower: Investment and operational planning under uncertainty

2022, Andreas Kleiven, PhD

The rapid development towards a more sustainable power system gives rise to complex stochastic optimization problems for hydropower producers.

In his thesis, Andreas Kleiven has worked on developing optimization models and methods for sustainable investment and operation of hydropower plants.

Webinar about the results

Long-term impact on unlined tunnels of hydropower plants due to frequent start/stop sequences

2021, Bibek Neupane, PhD.

New operating patterns in hydropower plants resulting from the supply and demand for electricity can lead to new challenges in conventional hydropower plants.

In his thesis, Bibek Neupane has tried to better understand how the long-term stability of unlined water tunnels is affected by frequent pressure pulsations due to repeated start/stop sequences.

Here you can find a webinar about the results.

Rock Stress Estimation for Unlined Pressure Tunnel Design

2021, Henki Ødegaard, PhD

Henki Ødegaard has looked at new methods for estimating the rock stress which hydropower tunnels are exposed to during the current operation of the hydropower plant.

Through his work in the lab and in the field, he has worked on a new test protocol that can function as a faster alternative to current methods for calculating rock stress.

Here you can hear more about the results.

Upgrading on Hydropower Plants to Pumped Storage Plants: Tunnel System Hydraulics

2021, Livia Ioana Pitorac, PhD

Pumping power can be used in periods when a lot of power is produced to pump the water back into the reservoirs again.

In her PhD, Livia Pitorac has looked at challenges and solutions with pumped power in Norway, and concludes that it is possible to upgrade existing hydropower plants to pumped power plants with today's tunnel systems without making major modifications.

Optimal control of variable speed hydropower. Utilising model predictive and virtual inertia for delivering power system services.  2021 Tor Inge Reigstad, PhD.

As the share of wind and solar energy production increases, more flexible production and loads are required to control the balance of the grid.  

In his Thesis, Tor Inge Reigstad proposes a new control method for optimal control of hydropower plants with variable speed. His work shows that the variable speed generators can provide significant stabilitation services to the network.

Trailing edge vortex shedding in hydraulic turbines and the effect of stream-wise vorticity on vortex induced vibrations, 2021. Kristian Sagmo, PhD.

Experiments as well as some numerical simulations were conducted investigating the resonance region of vortex induced vibrations for different trailing edges of a hydrofoil in channel flow.

The study focuses on the usefulness of stream-wise vorticity for the mitigation of vortex induced vibrations for the different trailing edge geometries.

Assessment on the swelling and disintegration potential of weak and weathered rocks in water tunnels of hydropower projects - a contribution based on use of laboratory testing methods, 2020. Lena Selen PhD.

The extensive laboratory work in combination with the wide-ranged cooperation has resulted in suggestions on project-specific modifications on standardized laboratory tests which enable an interpretation of weak rock behavior closer to the in-situ situation of water tunnels. Improvements are made explicit on the oedometer swelling test procedure in operation at the NTNU laboratory, including preparation techniques and apparatus configuration, and investments on new equipment is in progress. Additionally, the research includes an experimental application of the in-situ flatjack test normally used to measure in-situ stresses around tunnels which now is installed in a hydropower tunnel to measure changes in stress during the initial phase of operation. 

Hydraulic and structural evaluation of rockfill dam behavior when exposed to throughflow and overtopping scenarios. 2020. Ganesh Hiriyanna Rao Ravindra, PhD.

Ravindra has published several scientific articles during his PhD-research. He has investigated flow and overtopping of rock fill dams and, among other things, found that the dam toe can be crucial in extreme load situations such as overtopping. The data from the doctoral thesis will now be used to develop improve the design of the dam toe of rock fill dams. Read more about his research.

Francis turbines for variable speed operation. 2020. Igor Iliev, PhD. 

Iliev designed 421 hydropower turbines during his PhD-research and chose the best for variable speed operation. Read more about his research.

Experimental methods and design of a Pelton bucket

2016, Bjørn Winther Solemslie, PhD

In his PhD, Solemslie has looked at and developed a publicly available methodology on Pelton turbine geometry and design. He has also produced quantifiable current measurements of the current in the turbine and studied these.