Quadratic-Extended-Duty-Ratio Boost Converters for Ultra High Gain Application With Low Input Current Ripple and Low Device Stress

A new quadratic extended-duty-ratio (EDR) non-isolated boost converter is introduced here for ultra-high gain applications. The proposed converter is a combination of EDR boost converter and conventional quadratic boost converter. Quadratic boost converters can achieve high gain with lower component count while the EDR boost converter has low device stress while achieving high gain. A novel Quadratic EDR (Q-EDR) boost converter is proposed which is capable of attaining ultra high gain at moderate levels of duty with low voltage and current stress across different devices. Two different configurations of the proposed topology are presented with the interleaved version being able to reduce the current ripple further and the converter can be extended to M-phases in both the configurations. Detailed analysis of a 4-phase converter is presented along with converter design considerations. The performance of the proposed topology is validated through a 1 kW, 4-phase hardware prototype operating at 20 V-36 V input to 600 V output at 60 kHz. Experimental results corresponding to both interleaved and non-interleaved converter configurations are presented. Experimental results show that the converter can attain a conversion ratio of 30 at an operational duty close to 0.64 in the interleaved configuration. The switch voltage stress is limited to 150 V and quadratic stage diode voltage stress is limited to be less than 100 V for 600 V output condition enabling the use of low voltage devices. The converter is able to achieve a peak efficiency of 95.82% for 36 V to 600 V operation at 660 W.