This comparative study examines the application of nonlinear control strategies to pulse width modulation-controlled current source converters (PWM-CSCs), with a focus on proportional-integral (PI) control and proportional-integral passivity-based control (PI-PBC). PWM-CSCs play a crucial role in power electronics, enabling precise current flow regulation and control, which is essential for maintaining stability and achieving accurate management in electrical systems. Additionally, this paper highlights the significance of adaptive load estimation, which facilitates real-time adjustments to control strategies, thereby enhancing system efficiency and performance. By thoroughly analyzing dynamic models and control methodologies, this study demonstrates how the PI-PBC approach effectively stabilizes the system’s incremental model to ensure optimal operation. The findings contribute to the advancement of control techniques in power electronics, offering valuable insights into the implementation of strategies for optimizing current regulation in complex electrical systems.