An interleaved boost DC-DC converter with large conversion ratio

A new PWM dc-dc converter is introduced in which large voltage step-up ratios can be achieved without high duty-cycle, with low voltage and current stress and without transformer. The proposed circuit is an extension of the boost interleaved converter, incorporating a multistage capacitor multiplier. A simple nondissipative snubber can be used reducing the reverse recovery current of the diodes and also obtaining low turn-on and turn-off losses. The modularity of the structure allows the increment of the current, voltage and power levels, using the same range of components and maintaining high efficiency, only increasing the number of series and parallel stages. The paper gives a theoretical analysis, and experimental data on a 400 W example that was built and tested: 24 Vdc input, 200 Vdc output, and 40 kHz switching frequency. The measured performance agreed well with the theoretical predictions and the measured efficiency obtained is equal to 95% at full load.