Candidate: Edmilton Oliveira Stein
Program: UFSC / POSMEC
Date: March, 2025
Advisor: Victor Juliano De Negri, Dr Eng.; Marcos Paulo Nostrani, Dr.
Abstract: This thesis addresses the inefficiencies and limitations of traditional hydraulic systems used in speed governors for Francis turbines in hydroelectric power plants. Particularly, their need forlarge volumes of hydraulic fluid, which presents significant environmental and maintenance challenges. Additionally, the complex components of conventional speed governors are difficult to modernize and maintain, with replacement parts often being expensive or unavailable. To address these issues, this master’s thesis proposes a decentralized system based on electro-hydrostatic actuators (EHA). This approach eliminates the need for traditional control valves and significantly reduces the hydraulic fluid required. The study begins with a brief literature review on hydroelectric power plants, focusing on Francis turbines and their speed governors, followed by a review on EHA configurations, identifying a suitable architecture for speed governors in hydroelectric power plants. The proposed system relies solely on off-the-shelf products, simplifying implementation and reducing maintenance costs. The system modelling, performed using Hopsan and Matlab Simulink, assesses the performance of the new architecture. The results show that the system effectively manages common challenges in speed governors, such as overspeeding and fast position changes caused by minor fluctuations in electrical power demand. Furthermore, the proposed system’s simplified architecture makes maintenance easier by eliminating complex components, enhancing its adaptability for future modernization and maintenance.
Eng.Referência (STEIN, E. O. Modeling and Analysis of a Pump Controlled System for Speed Governor in Hydroelectric Power Plants. 2025. 137 p. Dissertation (Master) – Course of Mechanical Engineering, Department, LASHIP, Federal University of Santa Catarina, Florianópolis, 2025.)
