Novel topology and control of a non-isolated three port DC-DC converter for PV-battery power system

Abstract

In this paper, a novel three-port converter(TPC) for stand-alone photovoltaic(PV) power system application is proposed, and also presents the control strategy and power management of this converter. This converter uses three power switches, two inductors and switched capacitor structure to obtain a higher voltage gain and reduce the voltage stress of the power switches. The control for the converter has been proposed for realizing maximum power point (MPPT), battery protection, and output voltage regulation simultaneously. Furthermore, the controllers are decoupled from each other and can be automatically switched between different operational modes according to different external conditions. Therefore, the control strategy can control power flow reasonably and simply. Experiments have been carried out on a 300W prototype of the TPC, which control strategy is also built with a digital signal processor.