Current-mode bi-directional single-inductor three-port DC-DC converter for portable systems with PV power harvesting

This work targets low-power portable electronic applications with PV power harvesting. A bidirectional dc-dc converter is required to interface the battery with the load and PV module. A new current-mode scheme is applied to the single-inductor three-port converter, where the peak and valley inductor current are controlled by two separate digital regulation loops. The controller is shown to regulate both the PV voltage and the load voltage in the presence of load and irradiance steps. In solar deficit mode, energy is transferred from the battery to the load indirectly through the PV node, eliminating the two input switches used in conventional dual-input, dual-output converters. The scheme is demonstrated on a digitally controlled 1 W harvester prototype.