Abstract

A high step down transformerless integrated buck buck-boost converter is presented in this paper which is suitable for universal line applications (90-270 Vrms). The topology integrates a buck converter with a buck-boost converter with low intermediate voltage and output voltage. Buck converter acts as a PFC cell and buck-boost converter as DC/DC cell and as a whole the converter performs power factor correction. The converter is able to achieve efficient power conversion, high power factor and low output voltage under all input and output conditions without step-down transformer due to direct power transfer and sharing of capacitor voltages. The absence of transformer reduces the component count, size and cost of the converter. The circuit is successfully tested using MATLAB/Simulink.