Circuitry and analysis of input-capacitor-added multiple-input buck converters

Characterised as more straightforward topology, less components and simpler control, multiple-input (MI) converters are becoming active to be studied and implemented in renewable energy hybrid systems (REHSs) in the recent decade. In this study, a complete and systematic circuitry analysis of conventional MI buck converter (MIBC) and input-capacitor-added (ICA) MIBC topologies is clarified. Proceeded from the derivation of the input current of the utilised power source, a series of general equations of both conventional and ICA MIBCs that describe the circuits' electrical characteristics and behaviours are deduced, in the form of the kth practical source and considering the influence of equivalent series resistor(s), which are not put forward in previous literatures. The value of k can be any positive integral theoretically. The accuracy of these formulas is verified by comparing with the test results, combined with which, the impacts of the four main circuit parameters on the power sources are also discussed. The introduction of ICA MIBC is aimed at showing its specific capabilities and advantages in applications of REHSs, beyond conventional MIBC topology. The circuitry analysis, the proposed equations and the comparing discussion in this study do practically benefit to theoretical research, industrial application and power budgeting of MIBC.