  A family of interleaved current-fed high step-up dc-dc converters are
introduced and analyzed here by combining a voltage multiplier (VM) and an
active clamp circuit for high-voltage high-power applications. Low input
currents and output voltages ripples values and high voltage-gains
characteristics of these converters make them suitable for lots of dc-dc
applications. All power devices operate entirely under soft switching
conditions, even when wide load and input voltage variations are applied. Thus,
they can be designed at high switching frequencies to reduce passive components
sizes to achieve high-power density, one of the main targets of the power
electronics researches. Also, their input and output ports common ground
simplifies the gate-drives and control circuits. To verify the given analyses
and simulations, a 120-320 V to 1 kV, 50-1300 W three-stage two-leg prototype
converter has been implemented at 100 kHz. Based on the experimental results,
maximum efficiency of 96.5% is achieved.
