Analysis and Model of a Hydroelectric Power Plant for Simulating Ramp Rates

Open Access
Author:
Kunkel, Douglas David
Area of Honors:
Mechanical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Horacio Perez Blanco, Thesis Supervisor
  • Zoubeida Ounaies, Honors Advisor
Keywords:
  • hydroelectric ramp rates turbine controller power
Abstract:
As the world seeks to produce power more efficiently while minimizing environmental consequences, hydro and wind power generation become increasingly important. Hydroelectric power plants have the flexibility of changing their power generation output more quickly than traditional power plants. Because of this, hydropower can complement wind farms whose power output is dependent on weather conditions. Also, because the demand for power is not static, hydropower can also be used to supplement nuclear or fossil fuel power plants as needed. In order to meet the fluctuating power demands, it is important that these plants can adjust their output in a timely manner. Francis runners operate within a range of 60-100% of design capacity. The purpose of this thesis is to model a midrange plant with a Francis impeller with a maximum power output of 200 MW. The model will include the reservoir, penstock, and turbine. Most of the research has been done based on controlling the rotational speed of the turbine. However, as it has become possible to monitor shaft torque, this model attempts to control the power output directly. The simulated controller will detect a difference between the power required by the grid, and the power currently being generated. The controller then opens or closes the wicket gates changing the mass flow rate into the turbine as necessary. The whole concept hinges on the ability to design the gates so as to keep rotational speed constant. The results show that the turbine is able to go from 60% to maximum capacity in twelve seconds and back down in fifteen seconds. These ramps were negotiated with only small deviations from desired speed: within 1.5% or better than design. Overall, this model controls power proficiently, and if a proper wicket gate function can be implemented then the model can be useful to future designers.