In this paper, a novel high-gain DC–DC converter which is suitable for integrating low-voltage renewable energy source with a common DC bus is presented. The proposed converter is synthesised from a quadratic boost converter (QBC). Two QBC structures are interleaved to reduce the current ripple at the input port (12.9% of input current). The voltage conversion ratio of the proposed interleaved quadratic boost converter (IQBC) is extended by using the voltage lift technique. The energy storage inductors are judiciously coupled to realise a compact IQBC. Experimental results obtained from a 24 to 380 V, 100 W prototype converter validate the novel gain extension method and proposed design concepts. Under full-load condition, the practical efficiency value of the proposed converter is 92.49%. By implementing a simple closed loop, the output voltage of the proposed converter is regulated and maintained constant at 380 V when the input voltage and load current change. Under practical conditions, the percentage voltage regulation and the time response characteristics of the proposed IQBC are extremely satisfactory. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.