Stabilization Effect on Hydrogen Pressure for Fuel Cell Fueled by Sodium Tetrahydroborate With Multiple Power Converter Control

A hydrogen generation system for fuel-cell (FC) hybrid electric vehicles fueled by powdery sodium tetrahydroborate (STEPS) has been proposed and developed. In this system, it is difficult to control the pressure of the hydrogen supplied to a FC stack. This problem may cause damage to the solid polymer electrolyte membrane of the FC stack or an imbalance in the generated electrical power. As a solution to this problem, a control method that uses multiple power converters, consisting of boost and bidirectional choppers, is applied to a prototype vehicle fueled by STEPS. The proposed control method can suppress rapid variation in the output power of the FC stack. This study shows that the proposed control method can improve the performance of hydrogen pressure control through test runs using a prototype vehicle and simulations using the derived model.