Análise de técnicas de controle para produção de hidrogênio verde com energia fotovoltaica

Abstract

This dissertation aims to develop and implement a PID control system for a Buck DC-DC converter, designed to provide a stable direct current (DC) power supply to an electrolytic cell powered by photovoltaic modules, thereby ensuring the continuous production of green hydrogen despite inherent variations in photovoltaic generation. The methodological approach encompasses the modeling of the photovoltaic array and the converter, as well as the simplified representation of the electrolytic cell through an equivalent electrical model. These are integrated within the MATLAB R2026a Simulink environment, where various classical PID controllers and their variations are implemented and evaluated in terms of transient performance, robustness, and disturbance rejection. For each controller, tuning parameters, step response curves, and performance metrics, such as settling time, overshoot, steady-state error, and sensitivity to perturbations, are obtained. The results demonstrate that simple controllers, such as P and I, present significant limitations, either due to their inability to eliminate steadystate error or their excessively slow response. Compound controllers, such as PI and PID, exhibit superior performance but remain sensitive to abrupt input variations. Advanced configurations, particularly the I-PDF controller, prove to be more effective in stabilizing the voltage and current supplied to the electrolytic cell under simulated conditions, demonstrating improved performance against disturbances, greater rejection of irradiance variations, and higher robustness to process nonlinearities. The final simulations confirm that the I-PDF controller provides the best compromise between dynamic performance, achieving a settling time of 3 ms, and ideal robustness, presenting a value equal to 1, guaranteeing stability even in scenarios of partial shading or rapid fluctuations in photovoltaic generation. In conclusion, the application of advanced control techniques in DC-DC converters is essential to make green hydrogen production systems directly powered by solar energy viable, ensuring efficient, safe, and continuous operation, as well as paving the way for future optimizations and real-world system implementations.