High Step-Up DC-DC Converter by Integration of Active Switched Inductors, Built in Transformer, and Multipliers

This article presents a novel high step-up dc/dc converter by integrating active switched inductors, built-in transformers (BITs), and multipliers. The turn ratio of the BIT provides an extra degree of freedom. Hence, ultrahigh voltage gain is achievable by proper duty cycle and adjusting turn ratio. Multipliers are used to reach high voltage gain even with the unity turn ratio of the transformer. This feature is an effective factor to improve the efficiency. Further, the voltage stress of switches is reduced. It causes the reduction of conduction losses of switches due to the lower resistance of low voltage power mosfets. An efficient passive clamp circuit is used to cancel the voltage oscillation of the switches caused by the mismatch of inductors. Regarding these specifications, power losses decrease, and the efficiency is improved. The proposed converter is analyzed theoretically, and the validity of theoretical analysis is verified by constructing a 40-400 V, 200 W prototype.