Study of Dual Z-Source DC-DC High-Gain Converter for Hydrogen Fuel Cells

[Objective] In response to the insufficient boost capability and excessive device stress when conventional converters are applied to hydrogen fuel cell grid connection， a low electrical stress high-gain single-switch converter based on a dual Z-source network （LEHGSSC-DZ） is proposed. [Methods] This converter places the switching transistor in the quasi-Z source converter upfront to reduce device stress. Simultaneously， one of the inductor components is replaced with a quasi-Z source network， forming a dual-Z source network structure to enhance the converter's boost capability. The operating principle and output characteristics of the converter are analyzed， and a comprehensive comparison is made between the LEHGSSC-DZ and several other high-gain boost converters. Component parameter design is provided based on its output characteristics. The correctness of theoretical analysis and the feasibility of LEHGSSC-DZ are verified through simulations and experiments. [Results] The results demonstrate that the LEHGSSC-DZtopology employs fewer devices and offers superior cost-effectiveness. Compared to conventional Z-source boost converters， it achieves a 43.8% increase in output voltage， while delivering an output voltage that is 5.1 times higher than that of conventional boost converters. Furthermore， it reduces switching device voltage stress by 30%. [Conclusions] The proposed converter offers the distinct advantages of low electrical stress， high gain， and minimal device count， achieving a maximum efficiency of 97.25%. This contributes to enhancing the operational efficiency of hydrogen fuel cell grid-connected systems.