Non-Isolated High Conversion Ratio Boost Extender Based on Back-end Series Capacitor Stacking

Abstract

A non-isolated high conversion ratio boost extending method is presented. The extender approach hinges on the stacking of series capacitors, to achieve high voltage gain, along with high efficiency. The series capacitor stacking method, facilitates a high efficiency single cycle energy conversion that eliminates the need in multiple consecutive conversions typical for high gain non-isolated converters. In addition, the topology and stacking approach features low voltage stress across the diodes and stacked capacitors. An analysis of the voltage gain and component stresses for the general case is carried out, and experimental prototype of 125W is developed and built in the laboratory. The converter attains maximum efficiency of 95.5% at input voltage of 20V and output voltage of 210V. The experimental results are in a good agreement with theoretical predictions.