This article presents the development and implementation of a proportional-integral passivity-based control (PI-PBC) method for voltage support in energy conversion systems, specifically utilizing a pulse-width modulation current source converter (PWM-CSC). The increasing demand for highly efficient and reliable energy conversion systems has driven the exploration of advanced control strategies, particularly in applications with variable loads and nonlinear dynamics. The proposed approach incorporates an adaptive load estimation mechanism, allowing the control system to dynamically adjust its parameters in response to real-time load variations. This enhances both system stability and converter performance, ensuring efficient operation across a wide range of load conditions. Simulations show that the PI-PBC method delivers precise voltage regulation, which is critical for the integration of renewable energy systems and microgrids. The results demonstrate PI-PBC’s potential as a robust solution for nonlinear control in power electronics applications, offering stability and adaptability in demanding operational environments. This work advances the field of energy systems by proposing a theoretical and practical framework that can be leveraged in future research and technological developments.