Implementation and control of a buck–boost converter connected to a constant power load in a DC microgrid

This study proposes an adaptive nonlinear controller based on advanced nonlinear disturbance observer (ANDO) and passivity-based control (PBC) to ensure the stability of a buck–boost converter (BBC) in a DC microgrid (DCMG) by addressing the negative incremental impedance caused by constant power loads and the instability and oscillations resulting from right-half plane zeros. PBC stabilizes the system in the absence of uncertainties, while ANDO guarantees stability and assists PBC in keeping the converter stable in the presence of disturbances and uncertainties. The simulation results demonstrate its superior performance compared to the PBC-based controller. Hardware implementation further validates the effectiveness of the proposed controller in controlling the output voltage of the BBC, making it a promising solution for DCMG applications such as shipboards, electrical vehicles, and so on.