Control strategies and experimental validation for high-gain non-isolated double inductor boost converter

Abstract

In this paper, a control design methodology for a high-gain non-isolated double-inductor boost converter is proposed. The studied topology of the converter is based on a traditional boost converter operating under the inductor-switched method to obtain a high-voltage gain with a low-duty cycle. Based on the proposed methodology, three control laws are obtained. The proposed control strategies consist of two decoupled control loops: an inner loop aimed to track the input current to a desired current reference and an outer loop addressed to regulate the converter output voltage to a constant reference value. For the inner control loop, first a proportional action is proposed in order to provide damping to the system. In addition, the proportional controller is enhanced using an estimation scheme, based on immersion and invariance theory to deal with the effect of inductor parasitic resistances on the system. The third controller is a proportional-integral action in order to guarantee the current tracking objective. On the other hand, the control design of the output voltage loop results in a PI controller for the three cases which is aimed to regulate the output voltage of the converter. The performance of the proposed control laws is validated in three experimental scenarios: steady-state, input voltage changes and output resistance changes. Output voltage regulation and input current tracking are the main results obtained in each case.

Keywords

• High gain DC-DC power converter
• Proportional-integral control
• Disturbance estimator
• Immersion
• Invariance