Transformerless hybrid buck converter with wide conversion ratio
Conventional dc--dc converters are unable to provide very high step-down\nconversion ratio due to the inherent limitation of power switches\nand rectifier diodes in turning on and off instantaneously. Since\nutilization of transformers to make high conversion ratio imposes\nefficiency obstacle, more efficient transformerless converters have\nbeen proposed. With transformerless hybrid converters high step-down\nconversion ratio will be achieved and also efficiency problem will\nbe vanished. In this paper a hybrid buck converter formed by two\ninductors and two diodes is considered in discontinuous conduction\nmode (DCM). Critical values of circuit components are analytically\ndetermined and compared with conventional buck converter. It is shown\nthat using the hybrid buck converter, smaller conversion ratio may\nbe achieved in comparison with conventional buck converter in both\nDCM and CCM. Experimental results are illustrated for a hybrid buck\nconverter (100W, 5V). The experimental results confirm simulations\nand analytical achievements.