This study proposes a novel non-isolated high-gain high-power DC-DC converter. The converter is developed from a basic high-gain high-power converter structure. The proposed converter comprises of a three-phase interleaved boost converter, one coupled inductor and a voltage multiplier cell which act as gain extension stage. The main desirable features like voltage gain, stress on the switches and diodes, turns ratio, component utilisation factor and efficiency are summarised. The power circuit, operational details, simulation and experimental results of the 60 V/1.1 kV, 3 kW, 100 kHz proposed converter are presented. © The Institution of Engineering and Technology 2016.