Analysis and Performance Evaluation of a Cubic Buck Converter

This paper presents an analysis and performance evaluation of a cubic buck converter. The converter is developed from three buck converters connected in series and uses only one active switch. The proposed circuit has a voltage step-down gain equal to the cube of that provided by a single buck converter. Therefore, it is suitable for use in applications requiring a high voltage step-down, e.g. the conversion of a high DC voltage produced by solar arrays to directly supplying a low-voltage DC load. In the paper, the circuit analysis of the cubic buck converter is performed. The prototype circuit operating with the input voltage of 150 V, the output voltage of 5 V, the load current of 1–10 A and the switching frequency of 100 kHz is implemented. Experimental results confirm that the prototype circuit can maintain the output voltage 5 V throughout the load current range. In addition, the voltage and current measurement results are consistent with the theoretical analysis.