Non-isolated high step-up DC-DC converter with minimum switch voltage stress

In this paper a new high step-up DC-DC converter topology is presented, featuring minimum switch voltage stress as well as a reduced energy in the magnetic device compared to a standard Boost converter. Starting from the basic voltage-doubler charge pump cell, a modification is proposed to make the flying capacitor voltages dependent on the converter duty-cycle. The use of an additional charge pump cell allows the elimination of any parasitic oscillation across the diodes. Suitable design criteria are proposed so as to achieve the desired converter operation mode, without need for any iterative process. Experimental results based on a 44 to 400 V-300 W prototype confirm the theoretical analysis and expectations.