A novel high step-up DC-DC converter combining KY and CUK converters for fuel-cell system applications

A novel high step-up dc-dc converter which combinig ky and cuk converters for fuel cell system applicationshas been proposed in this paper. The voltage conversion ratio is greater, which combines one KY converter, one cuk converter and one coupled inductor with the turns ratio. The proposed converter consists of two-phase version configuration. A cuk type converter is integrated to the first phase to achieve a much higher voltage conversion ratio and avoid operating at extreme duty ratio. In addition, additional capacitors are added as voltage dividers for the two phases,which provide a boost operation for the second phase this proposed converter. So, the second phase of the proposed converter is a boost circuit. This converter possesses high gain ,non-pulsating output current, and also reducing the output voltage ripple. A detailed description of the proposed converter is presented along with a simple mathematical deduction and some experimental results. Finally, prototype system is also constructed to verify the effectiveness of the proposed converter.