The document presents a comparative study of two methods for automatic flow control in centrifugal pumps using numerical simulations. It focuses on modeling the hydraulic, mechanical, and electrical components to analyze the dynamic response and power consumption of a system with a control valve versus one with a variable speed drive, revealing that the latter is more energy-efficient. The study finds that while both methods maintain constant flow under pressure disturbances, the variable speed drive significantly reduces power consumption and minimizes mechanical issues, despite introducing harmonic distortion.