• Combining measurements with models for superior information in hydropower plants 

      Vytvytskyi, Liubomyr; Lie, Bernt (Peer reviewed; Journal article, 2019)
      Water flow and pressure measurements play essential roles in the operation of hydropower plants. For all methods of measuring flow and pressure, there is a level of uncertainty with regards to sensor noise and sensor ...
    • Comparison of elastic vs. inelastic penstock model using OpenModelica 

      Vytvytskyi, Liubomyr; Lie, Bernt (Journal article; Peer reviewed, 2017)
      The possibility for modelling and simulating hydropower systems as accurately as possible take an important role in order to develop a control structure and to make efficient analysis tools for testing a designed controller ...
    • Dynamics and model analysis of hydropower systems 

      Vytvytskyi, Liubomyr (Doctoral dissertations at the University of South-Eastern Norway;37, Doctoral thesis, 2019-09-06)
      Globalization and growth in energy consumption in combination with climate challenges, make the use of sustainable energy production a necessity. Important sustainable energy sources (solar, wind) are intermittent in ...
    • Hydropower Systems: Comparison of Mechanistic and Table Look-up Turbine Models 

      Splavska, Valentyna; Vytvytskyi, Liubomyr; Lie, Bernt (Journal article; Peer reviewed, 2017)
      In this paper, a detailed overview of hydropower system components is given. Components of the system include intake race, upstream and downstream surge tanks, penstock, turbine and draft tube. A case study which includes ...
    • Linearization for Analysis of a Hydropower Model using Python API for OpenModelica 

      Vytvytskyi, Liubomyr; Lie, Bernt (Journal article; Peer reviewed, 2018)
      Even though almost all processes in the real world are described by nonlinear models, nonlinear theory for analysis of these models is far less developed than the theory for linear models. Therefore model linearization is ...
    • Model based control for run-of-river system. Part 1: Model implementation and tuning 

      Vytvytskyi, Liubomyr; Sharma, Roshan; Lie, Bernt (Journal article; Peer reviewed, 2015)
      Optimal operation and control of a run-of-river hydro power plant depends on good knowledge of the elements of the plant in the form of models. River reaches are often considered shallow channels with free surfaces. A ...
    • Model based control for run-of-river system. Part 2: Comparison of control structures 

      Vytvytskyi, Liubomyr; Sharma, Roshan; Lie, Bernt (Journal article; Peer reviewed, 2015)
      Optimal operation and control of a run-of-river hydro power plant depend on good knowledge of the elements of the plant in the form of models. Both the control architecture of the system, i.e. the choice of inputs and ...
    • Modeling for control of run-of-river power plant Grønvollsfoss 

      Vytvytskyi, Liubomyr; Sharma, Roshan; Granstrøm, Ingunn; Lie, Bernt (Conference object; Peer reviewed, 2015-11-25)
      Design of optimal operation and control of a run-of-river hydro power plant depends on good models for the elements of the plant. River reaches are often considered to be shallow channels with free surface flow. A typical ...
    • Nonlinear observer for hydropower system 

      Vytvytskyi, Liubomyr; Sharma, Roshan; Lie, Bernt (Peer reviewed; Journal article, 2019)
      Estimation of unmeasured states plays an essential role in the design of control systems as well as for monitoring of hydropower plants. The standard Kalman filter gives the optimum state estimates for linear systems. ...
    • OpenHPL for Modelling the Trollheim Hydropower Plant 

      Vytvytskyi, Liubomyr; Lie, Bernt (Peer reviewed; Journal article, 2019)
      An increase of tightly integrated, renewable energy sources with highly varying production leads to a greater need for flexible hydropower plants to “balance” the intermittent production from these sources. From a systems ...
    • Structural analysis in Julia for dynamic systems in OpenModelica 

      Vytvytskyi, Liubomyr; Lie, Bernt (Peer reviewed; Journal article, 2019)
      In control theory for dynamic systems, the information about observability and controllability of states plays a key role to evaluate the possibility to observe states from outputs, and use inputs to move states to a desired ...
    • User’s guide for the Open Hydropower Library (OpenHPL) 

      Vytvytskyi, Liubomyr (Preprint; , 2019)
      OpenHPL is an open-source hydropower library that consists of hydropower unit models and is encoded in Modelica. Modelica is a multi-domain as well as a component-oriented modelling language that is suitable for complex ...