Controller Design and Validation for an Extended Step-Down Conversion Ratio DC-DC Converter

In this paper, the controller for an extended step-down conversion ratio converter is designed and experimentally validated through a laboratory prototype. The converter that is considered is formed by a conventional buck converter to which an array of capacitors and diodes is added at the input that allows extending the step-down conversion ratio. The objective of the controller is to provide closed-loop stability and assure the regulation of the output voltage. Its design is based on the averaged converter model and consists of two control loops, one voltage and one current. Closed-loop experimental results are presented.