A three port high gain non-isolated DC-DC converter for photovoltaic applications

In photovoltaic (PV) applications, power electronic converters play a vital role in transferring power from source to load. In general, operating voltages of PV arrays are low. To interface them with high voltage DC bus, a high voltage conversion system is needed which is provided by high gain topologies. Moreover, to increase the power density, efficiency of conversion and decrease cost, recent developments involve use of multiport converters which are in general multi-input converters capable of interfacing different renewable sources to a single structure. However many topologies reported in the literature achieve only nominal voltage gain between source and output. In this paper, a new topology is proposed by combining the advantages of both high gain and multi-input converters. The proposed topology has two input ports (i) A bidirectional port for energy storage device (ii) A unidirectional port for PV source. Coupled inductor technique is used to obtain high voltage gain. The topology along with theoretical analysis is presented to explain the principle of operation. This analysis is then compared with simulation results from MATLAB-Simulink to validate operating principle of the proposed topology.