Steady-state analysis of large step-down ratio two-input DC-DC converter

The paper presents a two-input large step-down ratio hybrid buck-SEPIC DC-DC converter. The conventional converters need to be operated at extreme duty ratios in applications where larger stepping down of voltages is needed. Such operating cases results in under utilization of the switching devices. In comparison to the conventional multi-input dc-dc converters the proposed converter is capable of providing extra bucking feature at moderate duty ratios. Through a time-domain analysis steady-state performance is established and then converter energy storage elements design expressions are obtained. A 60/48 V to 24 V, with power capacity of 200 Watt dc system is considered for analytical investigations. The proposed converter performance is compared with the conventional two-input Buck-SEPIC converter and then significant features are brought out.