Load current control of a boost converter using output redefinition

Control of the output current of a boost type DC-DC converter is challenging due to the non-minimum phase characteristic between the duty cycle input and output load current and the nonlinear dynamics involved. To address the control challenges, this paper presents a nonlinear control scheme combined with an output redefinition approach to regulate the output current of the converter operating in the continuous conduction mode (CCM). To this end, a feedback linearization controller is proposed based on an averaged model of the converter. The output redefinition concept relies on defining a new output to make the system minimum phase, or marginally minimum phase, so that a robust controller can be designed. Furthermore, control in the discontinuous conduction mode is studied and a switching scheme is presented to regulate the output current of the converter regardless of the operation mode. Numerical simulations are presented to evaluate performance of the proposed control scheme.