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.
