Feed-forward excess passivity-based control of buck-boost converters

Buck-boost converters are nonlinear, non-minimum phase systems with respect to their output voltage. Conventional controllers make use of a one-to-one correspondence between the voltage and current equilibriums. They exploit the stable zero dynamics of the inductor current to indirectly regulate the capacitor voltage. Indirect regulation of voltage is sensitive to circuit parameter and load variation. This paper introduces a passivity-based direct voltage control of buck-boost converters using feedforward compensators. The simulation results demonstrate a stable voltage behavior in the presence of system perturbations and load variations.