New family of transformer‐less quadratic buck‐boost converters with wide conversion ratio

Summary In this article, a component selection approach method is introduced to devise the new dc–dc converter topologies. This method is applied to the popular series‐shunt structure to derive a family of fourth‐order quadratic dc–dc buck‐boost type converters consisting of two synchronously operating active switches and two diodes for a wide conversion ratio. Even though four proposed converters have the buck‐boost ability, two of them can produce high step‐up gain, which can be used in renewable energy and electric vehicle applications; the other two converters give high step‐down voltage gain, which can be useful in applications such as portable electronic devices and integrated circuits. The proposed converters have low electric stress on power semiconductor devices for reduced power losses and increased efficiency. The operating principle, design, and the steady‐state performance of proposed converters are presented along with their small‐signal analysis. Furthermore, the proposed converters are compared with other buck‐boost type converters in terms of voltage gain, electric stress on power semiconductor devices, the availability of continuous input, continuous output, common ground, and output polarity. Finally, experiments are conducted on a 100‐W laboratory prototype to validate the performance of the proposed converters.