| Title |
Design and Control of Multiple Resonant LLC Converter with Parallel-Input and Series-Output for Hydrogen Fuel Cell Railway Vehicles |
| Authors |
Dong-Kyun Kim ; Jin-Chul Kim ; Jae-Bum Lee |
| DOI |
https://doi.org/10.6113/TKPE.2023.28.2.89 |
| Keywords |
Hydrogen fuel cell railway vehicles; Resonant LLC converter; Parallel-input and series-output; Multiple-module structure; High power density |
| Abstract |
Carbon emission regulations are being strengthened worldwide. Thus, research to utilize hydrogen fuel cells, which are an eco-friendly energy source with high energy efficiency, as a power source for railway vehicles is being actively conducted. Currently, a 3-Level boost converter with a relatively simple structure is applied as a step-up converter for a hydrogen fuel cell railway vehicle. However, it has difficulty designing a high power density because it cannot achieve soft switching. Therefore, a multi-resonant LLC converter with parallel-input and series-output structure is proposed as an alternative to the existing 3-Level boost converter. The proposed converter has high input/output gain in a wide range of output voltage variation. It is also easy to operate at high frequencies. Thus, it can achieve high power density for hydrogen fuel cell railway vehicles. In this study, frequency/duty ratio control is proposed to solve the problem of output voltage deviation between modules that may occur due to the multiple-module structure. A 12 kW-class prototype is manufactured and verified through hardware experiments to confirm the feasibility of the design and control of the proposed converter. |