Merging control for the hybrid energy storage subsystem of a Fuel-Cell Vehicle

The Toyota Mirai is a fuel cell vehicle with a hybrid energy storage subsystem (battery and fuel cell). Its small-size battery has a limited state-of charge (SoC) variation of only 10%. In order to reduce the fuel cell current peak, a new control scheme is proposed by merging two control laws. This merging offers a supplementary degree of freedom for the energy management strategy. In simulation, an increase the battery SoC variation by only 10% leads to 20% reduction of the fuel cell current for a WLTC driving cycle.