Ultrahigh Step-Up Quadratic Boost Converter Using Coupled Inductors With Low Voltage Stress on the Switches

In this article, a new ultrahigh step-up dc–dc converter is proposed. The circuit is composed of a quadratic boost converter (QBC), two coupled inductors (CIs), 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 all the compared converters, voltage gain of the converter in the entire duty cycle and the CIs 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 250 W and 600 V output power and voltage, respectively. In the experiments, the output voltage is controlled on its rated value of 600 V, while the input voltage varies from 15 to 30 V, meaning that the maximum experimental voltage gain is equal to 40.