A Multiple-Input Multiple-Output Bipolar DC-DC Voltage Gain Converter with Backup Battery Port

Photovoltaic (PV) arrays usually operate at a low voltage level. To integrate low renewable voltage with high voltage DC microgrid, a high gain DC converter is essential. Moreover, to enhance efficiency and reduce the cost, multiport converters play a pivotal role. Various topologies proposed in the literature achieve only low voltage gains from source to load. This paper presents a DC converter that achieves both a high gain output as well as multiport operation. The converter also integrates a storage device (battery) with renewable resource to provide backup in the absence of renewable energy. Bidirectional voltage flow is achieved through buck operation for battery charging. The proposed topology presents a four port converter with a voltage source, battery and asymmetric bipolar outputs, suitable for interfacing with DC microgrid and hybrid electric vehicles. Two inductors are used in the topology to achieve high voltage gain. Circuit operation, simulation, voltage gain and efficiencies are critically analyzed. Operation, design consideration and simulations at different levels of the proposed structure are presented.