Gramian based digital controller design for two-input integrated DC-DC converter

A gramian based digital controller design is proposed for a two-input DC-DC converter suitable to draw power from two different dc sources feeding a common dc-bus is presented in this paper. The proposed converter is simple and it belongs to sixth-order family performing bucking as well as boosting features. The salient features of this converter are that both the sources either individually or simultaneously supply power to the downstream load at reduced ripple current. Although this will be performing the load management, there is considerable interaction among the control loops. The issue of control-loops interaction is investigated in this paper by applying gramian based control theory. A digital voltage-mode controller is designed for downstream dc-bus regulation while the current controller regulates the power from the weak input power source. A 24 V, 96 Watt converter performance is analyzed and compared with the experimental observations.