Control of Split-inductor Based Buck-Boost Converter

A modified buck-boost converter suitable to point of load applications is presented in this paper. It gives better buck boost conversion ratio together with smooth source current waveform. Mathematical analysis, steady-state and time-domain analysis, is presented to identify the characteristic features of the proposed converter. The mathematical analysis based on network theory is established and are transformed into state-space models. A set of small-signal transfer functions are obtained and then used in the controller design. The proposed topology is able to perform bucking as well as boosting of input dc voltage to desired level just like the traditional buck-boost converter. Furthermore, the proposed circuit and has no inter connection issues as it has common ground. A 45 Watt, 100 kHz prototype fifth-order converter is built for performing experiments. The adopted load voltage is of either 48 or 15 V. A 24 V dc-battery is used for powering the prototype converter operation both in simulation and experimentation. The split inductor based converters' effectiveness is demonstrated, both in simulation platform and in real-time operation.