In this paper, a new ultrahigh step-up DC-DC
converter is proposed. The circuit is composed of a quadratic boost
converter, two coupled inductors and a voltage multiplier cell. The
distinguishing features of this converter are low voltage stress on
the main power switches, continuity of the input current, common
ground between load and source and ultrahigh voltage gain.
Among the all compared converters, voltage gain of the converter
in the entire duty cycle and the coupled inductor’s turn ratio
range, is higher and unique of its kind. A prototype is also
prepared in order to experimentally validate feasibility and
effectiveness of the proposed converter. This prototype is rated at
250W and 600V output power and voltage, respectively. In the
experiments, the output voltage is controlled on its rated value of
600V, while the input voltage varies from 15V to 30V, meaning
that the maximum experimental voltage gain is equal to 40.