A Plug-In Hybrid Electric Vehicle Concept with Fuel Cell Range Extender for Urban Delivery Transport – Vehicle Application

The electrification of vehicle fleets for urban delivery transport is becoming increasingly important due to ever stricter legal requirements and the high public pressure on companies. In this paper, a converted 3.5 t light-duty vehicle with a maximum gross weight of 7.5 t is presented. The vehicle has a serial hybrid electric powertrain with a maximum electric traction power of 150 kW and a 60 kW fuel cell range extender, and uses a 46 kWh battery with 400 V mean voltage level, resulting in a full electric range of 120 km. The electric drive is realized with an induction motor and a lithium-manganese-iron-phosphate (LMFP)-battery as well as a 2-speed gearbox. The fuel cell system has a fuel tank with 100 l volume and 700 bar pressure level, resulting in a total mass of around 4.2 kg of hydrogen. This enables an overall vehicle range of 400 km. For the fuel cell system, a newly developed concept with a rated power of 1.0 W/cm² and an electrically assisted turbocharger is introduced [1]. To reach optimal results for the electric and the hydrogen energy consumption, the vehicle applies an operating strategy based on the Equivalent Consumption Minimization Strategy (ECMS). This operating strategy uses a global optimization algorithm in combination with the local optimized hydrogen consumption provided by the ECMS, to calculate the minimum possible energy consumption for the vehicle. This is achieved by using a reference drive cycle in charge sustaining mode. The vehicle is afterwards simulated with two additional drive cycles. The first drive cycle is a low load urban driving scenario with an overall range 7.85 km, the second a medium load urban delivery scenario simulating a vehicle day tour of 150 km and an overall duration of around 6 h and 45 min. Both drive cycles are simulated in charge-depleting mode. Finally, the operation of the different powertrain components as well as the electric energy and hydrogen consumption is presented.