A Novel High‐Gain Low‐Stress DC‐DC Converter With Integrated Series–Parallel Boost Unit

ABSTRACT In a microgrid model, it is generally required that the DC‐DC converter can achieve a high boost ratio while having the advantages of high efficiency and low component stress. To meet the requirements, this paper improves the quasi‐Z‐source converter (QZS) by designing and integrating series–parallel boost units (SPBU) in combination with switching capacitors and switching inductors. Therefore, the voltage gain is increased while the stress of components is reduced, and high efficiency is achieved. This paper first describes the topology and operating principle of the proposed converter, establishes a mathematical model, and derives the voltage gain. Then, the voltage and current stresses of each component are analyzed based on the mathematical model. Next, the power loss of the proposed converter is calculated to determine its efficiency. Subsequently, a comprehensive comparative analysis is conducted between the proposed converter and existing converters in terms of voltage gain, switching stress, number of components, and peak efficiency, showing the advantages of the proposed converter. Finally, an experimental prototype of 200 W is fabricated for experimentation. The results show that at the duty cycle of 0.25, the voltage gain exceeded 5 and the efficiency reached 93.6%, verifying its feasibility and superiority.