Passive and Active Coupling Comparison of Fuel Cell and Supercapacitor for a Three-Wheel Electric Vehicle

The desire to reduce the power electronics related issues has turned the attentions to passive coupling of powertrain components in fuel cell hybrid electric vehicles (FCHEVs). In the passive coupling, the fuel cell (FC) stack is directly connected to an energy storage system on the DC bus as opposed to the active configuration where a DC-DC converter couples the FC stack to the DC bus. This paper compares the use of passive and active couplings in a three-wheel FCHEV to reveal their strengths and weaknesses. In this respect, a passive configuration, using a FC stack and a supercapacitor, is suggested first through formulating a sizing problem. Subsequently, the components are connected in an active configuration where an optimized fuzzy energy management strategy is used to split the power between the components. The performance of the vehicle is compared at each case in terms of capital cost and trip cost, which is composed of FC degradation and hydrogen consumption, and total cost of the system per hour. The obtained results show the superior performance of the passive configuration by 17% in terms of total hourly cost, while the active one only results in less degradation rate in the FC system.