The purpose of this dissertation is to analyze the operational arrangement to optimize the performance of large synchronous rotating electric machines, focusing on the phenomenon of stator core demagnetization in hydropower generators, given its relevance to the electricity generation sector. The study explores the mechanisms that lead to the occurrence of this phenomenon and analyzes technical aspects related to diagnosing and mitigating such occurrences, aiming to extend the lifespan of hydropower generators and ensure efficient operation over time, according to reliability criteria. Additionally, it seeks to demonstrate that when hydropower generators are subjected to recurring start-stop cycles to maintain energy reserves for periods of higher demand, the probability of demagnetization increases. To this end, the research was based on the magnetization tests of the stator core of Generator Unit 01G3 at the Boa Esperança Hydropower Plant and on the demagnetization of the stator core of the Auxiliary Generator of Unit 01G4 at the Sobradinho Hydropower Plant. The research methodology employed was applied, qualitative, explanatory, bibliographic, and based on case studies, grounded in the author's technical knowledge and experience, considering the limited academic literature available. The demagnetization of the stator core in hydropower generators is a unique occurrence classified as a significant random failure, which requires special attention from hydropower plant maintenance engineering. Thus, the need to investigate a computational model to study the demagnetization of the stator core of hydropower generators with electromechanical characteristics similar to those of the Auxiliary Generator of Operational Coding Unit 01G4 at the Sobradinho Hydropower Plant was identified, with the objective of analyzing the causes of the phenomenon and ensuring both the continuity of energy generation and the country's energy security. The expected results should indicate the most appropriate solution to minimize the recurrence of this type of failure, working towards ensuring the physical integrity of the hydropower plant arrangement and reducing operational costs. In this context, the importance of strategic planning, under the responsibility of hydropower plant maintenance engineering, is highlighted as fundamental to ensuring the availability of electricity generation at the plant. Predictive and preventive actions will significantly contribute to ensuring stable energy and greater energy security, reducing failure rates and improving energy quality indicators without unfeasible increases in operational costs. This reflects a commitment to the sustainable development of the electricity sector, based on the three dimensions of sustainability (environmental, social, and economic).