Design and Simulation of Advanced Materials Fuel Cell Hybrid Electric Vehicles 2019-01-0828

Two fuel cell hybrid electric vehicle (FCHEV) designs are being proposed and evaluated. The first is a baseline model inspired by a Toyota Venza (2009) design where the body of the FCHEV is mainly composed of steel/iron 67% while the plastic and aluminum forming only 14%, and with a body or glider mass of 1290 kg. The advanced model is based on a light body vehicle inspired from a Lotus Engineering design where plastic and aluminum constitute around 39 % of the total glider mass while mild steel and iron are only 7%. The use of such light materials allows the reduction of the glider mass by around 38.4 % down to 795 kg and a projected cost increase of 3% only. Although some material used are more expensive than steel/iron, the significant mass reduction offsets the increased cost due to using more expensive material. Furthermore, the mass of the added components in the advanced design was significantly lower than those added in the baseline. Both designs have similar dimensions, but the advanced design end up with a much lower curb weight and a corresponding lower fuel consumption. The optimal sizing of the fuel cell, battery, motor and hydrogen tank of the FCHEVs is achieved using a search tool based on Ordinal Optimization (OO). It incorporates a FCHEV optimal simulation tool that uses an approximate version of dynamic programming known as Single Stage Dynamic Programming (SSDP). The SSDP method is further enhanced as a Two-Step SSDP that reduces the operation simulation time to about one-fourth. The performances of the two designs were assessed on both the Highway Federal Emissions Test (HWFET) cycle and the Urban Dynamometer Drive Schedule (UDDS) cycle. The advanced design is shown to yield significant savings in H₂ consumption over that of the baseline.