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.