2.1 Variable speed operation
Variable speed operation
The production flexibility in our Scandinavian system relies on hydropower. In continental Europe, it is pumped storage and gas fired plants that can in an efficient way provide the production flexibility. This project focuses on enhancing the dynamics, operation flexibility and grid support capacity on power stations by using variable speed machinery based on converter-fed technology.
The future need is driven by several factors:
• The primary energy mix is going from large hydro designed for maximum energy production (as in Norway and Sweden) and large thermal units (continental Europe) to a more unpredictable and diversified energy mix from new-renewables such as wind power and solar power due to domestic investments and more power interchange capacity to UK and continental Europe.
• Increased end-user flexibility and energy-saving plans in industry and households may lead to more rapid load changes and larger differences between top and bottom power load.
• Market oriented operation of the power station is imposing new requirements and demands on the stations. The power output is more frequently adjusted causing more dynamic changes in the entire production system. The power plant operation is not generally optimized for energy production, but to maximize the income in a commercial market.
By introducing converter-fed synchronous generators, the dynamic capability will be strengthened substantially due to “synthetic inertia” and the converter improves the fault ride through by decupling the generator speed from the grid frequency. Reversible pump-turbines will operate smoothly, ramping rates will be faster, efficiency is higher at part load and the operating range of Francis turbines is wider.
Publications work package 2.1 Variable speed operation
Francis turbines for variable speed operation. Igor Iliev, PhD Thesis. NTNU. 2020.
Variable-speed operation of Francis turbines: A review of the perspectives and challenges. Iliev, Igor; Trivedi, Chirag; Dahlhaug, Ole Gunnar. Renewable & Sustainable Energy Reviews 2019 ;Volum 103. s. 109-121
NTNU
On the Rotor Stator Interaction Effects of Low Specific Speed Francis Turbines. Agnalt, Einar; Iliev, Igor; Solemslie, Bjørn Winther; Dahlhaug, Ole Gunnar. International Journal of Rotating Machinery 2019; Volum 2019. NTNU
Numerical prediction of hill charts of Francis turbines. Nordvik, Andreas; Iliev, Igor; Trivedi, Chirag; Dahlhaug, Ole Gunnar. Journal of Physics, Conference Series. 2019
Design and operation investigations for large converter-fed synchronous machines in hydropower applications. Erlend Løklingholm Engevik. PhD Thesis. NTNU 2019. Short summary.
Electromagnetic analysis and electrical signature-based detection of rotor inter-turn faults in salient-pole synchronous machine. Valavi, Mostafa; Jørstad, Kari Gjerde; Nysveen, Arne. IEEE transactions on magnetics 2018 ;Volum 54.(9) s. 1-9.
Influence of Converter Topology and Carrier Frequency on Airgap Field Harmonics, Magnetic Forces, and Vibrations in Converter-Fed Hydropower Generator. Valavi, Mostafa; Devillers, Emile; Le Besnerais, Jean; Nysveen, Arne; Nilsen. IEEE transactions on industry applications. vol. 54 (3). Roy. (2018)
Hydrodynamic Damping of a Fluttering Hydrofoil in High-speed Flows. Bergan, Carl Werdelin; Solemslie, Bjørn Winther; Østby, Petter Thorvald Haug; Dahlhaug, Ole Gunnar. International Journal of Fluid Machinery and Systems 2018 ;Volum 11.(2) s. 146-153. NTNU
Simplified hydrodynamic analysis on the general shape of the hill charts of Francis turbines using shroud-streamline modeling. Iliev, Igor; Trivedi, Chirag; Dahlhaug, Ole Gunnar. Journal of Physics, Conference Series 2018 ;Volum 1042.(1) s. NTNU
Pressure Pulsation in a High Head Francis Turbine Operating at Variable Speed. Sannes, Daniel B.; Iliev, Igor; Agnalt, Einar; Dahlhaug, Ole Gunnar. Journal of Physics, Conference Series 2018 ;Volum 1042. s. NTNU
Performance Comparison of Optimized Designs of Francis Turbines Exposed to Sediment Erosion in various Operating Conditions. Shrestha, K.P.; Chitrakar, Sailesh; Thapa, Bhola; Dahlhaug, Ole Gunnar. Journal of Physics, Conference Series 2018 ;Volum 1042. s.1-10. NTNU
Flow measurements around guide vanes of Francis turbine: A PIV approach. Thapa, Biraj Singh; Dahlhaug, Ole Gunnar; Thapa, Bhola. Renewable Energy 2018 ;Volum 126. s. 177-188. NTNU
Experimental investigation of a Francis turbine during exigent ramping and transition into total load rejection. Trivedi, Chirag; Agnalt, Einar; Dahlhaug, Ole Gunnar. Journal of Hydraulic Engineering 2018 ;Volum 144.(6) s. NTNU
Experimental study of a Francis turbine under variable-speed and discharge conditions. Trivedi, Chirag; Agnalt, Einar; Dahlhaug, Ole Gunnar. Renewable Energy 2018 ;Volum 119. s. 447-458. NTNU
Investigation of the Unsteady Pressure Pulsations in the Prototype Francis Turbines -Part 1: Steady State Operating Conditions. Trivedi, Chirag; Gogstad, Peter Joachim; Dahlhaug, Ole Gunnar. Mechanical systems and signal processing 2018 ;Volum 108.(8) s. 188-202. NTNU
Particle Image Velocimetry Investigation of the Leakage Flow Through Clearance Gaps in Cambered Hydrofoils.Chitrakar, Sailesh; Neopane, Hari Prasad; Dahlhaug, Ole Gunnar. Journal of Fluids Engineering - Trancactions of The ASME 2017 ;Volum 139.(9) s. -
NTNU
Numerical and experimental study of the leakage flow in guide vanes with different hydrofoils. Chitrakar, Sailesh; Thapa, Biraj Singh; Dahlhaug, Ole Gunnar; Neopane, Hari Prasad. Journal of Computational Design and Engineering 2017 ;Volum 6.(2) s. 218-230
NTNU
Blade passage modeling strategy for hydraulic turbine. International Journal of Fluid Machinery and Systems. Gong, Ruzhi; Trivedi, Chirag; Dahlhaug, Ole Gunnar; Nielsen, Torbjørn Kristian. 2017 ;Volum 10.(4) s. 345-354
NTNU
Effects of sediment erosion in guide vanes of Francis turbine. Thapa, Biraj Singh; Dahlhaug, Ole Gunnar; Thapa, Bhola. Wear 2017 ;Volum 390-391. s. 104-112
NTNU
Investigations of unsteady pressure loading in a Francis turbine during variable-speed operation. Trivedi, Chirag; Agnalt, Einar; Dahlhaug, Ole Gunnar. Renewable Energy 2017 ;Volum 113. s. 397-410
NTNU
Study of the simultaneous effects of secondary flow and sediment erosion in Francis turbines. Chitrakar, Sailesh; Neopane, Hari Prasad; Dahlhaug, Ole Gunnar. Renewable Energy 2016 ;Volum 97. s. 881-891. NTNU
Transient pressure measurements at part load operating condition of a high head model Francis turbine. Goyal, Rahul; Trivedi, Chirag; Gandhi, BK; Cervantes, Michel; Dahlhaug, Ole Gunnar. Sadhana (Bangalore) 2016 ;Volum 41.(11) s. -. NTNU
Experimental and Numerical Studies of a High-Head Francis Turbine: A Review of the Francis-99 Test Case. Trivedi, Chirag; Cervantes, Michel; Dahlhaug, Ole Gunnar. Energies 2016 ;Volum 9.(2) s. 1-24. NTNU
Numerical techniques applied to hydraulic turbines: a perspective review. Trivedi, Chirag; Cervantes, Michel; Dahlhaug, Ole Gunnar. Applied Mechanics Review 2016 ;Volum 68:010802.(1) s. - NTNU
Master thesis
Else Høeg Sundfør. Design and operation of a Francis Turbine with Variable Speed Capabilities
Madeleine Josephine Selvig Hallén. Simulation of Rotor-Stator Interactions (RSI's) in a High Head Francis Turbine
Daniel Braathen Sannes. Pressure Pulsation and Stresses in a Francis Turbine Operating at Variable Speed
Mathias Gallefoss. Synthetic Inertia from a Converter-Fed Synchronous Machine in a Hydro-Electric Power Plant - Modeling, Control and Analysis
Andreas Blix Møller. Modelling, Simulation, and On-line Detection of Rotor Eccentricity in Hydropower Generators
Contact
About the project
Full project title: Variable speed operation
Duration: 2016 - 2021
Objective: Develop new technical solutions for variable speed operation for hydropower and pumped-storage plants.
R&D Partners: USN, Uppsala University (UU), Luleå Technical University (LTU), Chalmers Technical University, Kathmandu University (Nepal), Statkraft, Rainpower
Associated projects: HiFrancis, HydroStator, MonitorX, Francis levetid.
Researchers working on the project: Arne Nysveen, Ole Gunnar Dahlhaug, Roy Nilsen, Olve Mo, Karl Merz, Atsede G. Endegnanew, Tuan T. Nguyen.
PhD working on the project: Igor Iliev, Erlend Engevik and Raghbendra Tiwari
Post doc. working on the project: Bjørn Solemslie and Mostafa Valavi
Master students associated with the project: Arne Moen Lid, Else Høeg Sundfør, Madeleine Josephine Selvig, Daniel Braathen Sannes, Mathias Gallefoss, Solrun Ova Venås Kvendbø, Andreas Blix Møller, Andreas Nordvik, Eirik Lødemel, August Jaros, Jose Armando Romero Amaya, Georg Hurst, Gro Mari Kjellstadli Langleite, Thomas Grong, Sophie Berg, Fredrik Bjørken.