Sensorless Indirect Voltage Control of a Buck Converter Feeding an Unknown DC Load: Predictive Digital Current Control

This paper presents a predictive digital current control strategy for regulating the output voltage of a DCDC buck converter feeding an unknown DC load current. The proposed control includes a PI controller to compute the inductor current reference based on the error between the desired and measured voltage. Additionally, two observers are implemented to estimate the buck converter’s DC load current and input voltage to ensure convergence to real values. Numerical simulations using MATLAB/Simulink show that the proposed control effectively regulates the output voltage even with variations in input voltage and DC load current. Furthermore, the proposed control is compared to the cascade loop PI controller and performs better than the PI control.