Improved interleaved high step-up converter with high efficiency for renewable energy applications

Abstract

A new super-boost converter, which is appropriate for renewable energy applications, is proposed in this paper. The proposed converter consists of switched capacitors and two coupled inductors. This combination can provide a relatively high voltage boost gain while operating with small duty cycle. The converter can be powered either by one individual DC voltage source in an interleaved manner or two independent DC voltage sources as a multiport converter. The configuration of the proposed converter has advantages such as low power losses, longer lifetime of input sources due to non-pulsating input current, low voltage stress across the main switches and slight output voltage fluctuation. Using this converter, a 22.5 times gain can be reached with 0.6 duty ratio and turns ratio equal to 2 that makes it possible to connect a 20V PV system to a 450V DC bus. Theoretical analysis and simulation results are presented to demonstrate the authenticity of the proposed converter.