A robust nonlinear PI-type controller for the DC–DC buck–boost power converter

In this study, a novel Lyapunov function-based robust nonlinear proportional–integral (PI)-type controller for regulating the output voltage of the direct current to direct current (DC–DC) inverting buck–boost power converter operating in continuous conduction mode (CCM) is presented. The control scheme guarantees global asymptotic stability of the closed-loop system even in case of parameter uncertainty. The analysis of the closed-loop trajectories is carried out using Lyapunov method and LaSalle's invariance principle. Robustness to additive disturbances is shown and simple gain tuning guidelines are given. Real-time experiments support the theoretical results. Experimental tests are presented where the proposed PI-type control design is compared with other PI-type schemes found in the literature. The proposed scheme presents very good consistent performance under line and load disturbance.