Capacitor-less Multiport Converter: Analysis, Switching, Modelling and Control

In the recent years, many different multi-port converters have been proposed for multi-source multi-load applications in order to improve the features of a hybrid system such as cost, size, efficiency and life time. This paper surveys and develops a capacitor-less three-port converter which has been presented to eliminate the bulk capacitor in common DC bus. In this paper, several switching approaches are proposed for this converter and implementation methods of them are described and evaluated. In addition, considering constant voltage in one of the ports, a small signal model is extracted for the converter which has five state variables due to existence of two capacitors and three inductors. In order to control different port independently, using an innovative method, the converter outputs are decoupled. Finally, a control system based on magnitude optimization is presented for the converter. Simulation results are used to verify the validity and the performance of the proposed approaches and analysis's.