Ripple Improvement and Steady State Analysis of a Boost Converter with Higher Step-up Ratio

In this paper, a ripple improved DC-DC boost converter is proposed by using a dual-winding directly coupled coupled-inductor operating in continuous conduction mode (CCM). The proposed converter achieves larger step-up conversion ratio than the conventional boost converter by using a diode-capacitor cell. The cell consists of two crossly connected identical capacitors and two diodes placed in parallel. An inductor is required to be placed in the output-end to oppose the sudden change in load current due to series-parallel configuration of the identical capacitors of the cell. Thus, the converter requires two inductors to achieve the voltage gain. These two inductors are replaced by a dual-winding directly coupled coupled-inductor. This modification in the circuit improves the ripple in input and inductor currents and, ripple in output voltage without affecting the conversion ratio. Apart from that, the reduction of size of magnetic core also reduces the cost and bulkiness of the proposed converter.