Series hybrid powertrain simulation and hardware-in-the-loop application for a light-duty nontactical vehicle

An improvement in the fuel economy of nontactical vehicles has and continues to be a significant initiative for US military ground vehicles. This paper investigates the potential improvement in the fuel economy of a prototype-built nontactical series hybrid cargo van. A baseline conventional vehicle is first modeled and validated. The current series hybrid van equipped with a lead–acid battery pack and an a.c. induction traction motor is then modeled and simulated in two driving cycles. A vehicle equipped with a nickel–metal hydride battery pack and a vehicle with a lithium-ion battery pack, together with an optimal hybrid powertrain control strategy, are simulated for further improvement in the fuel economy. The simulation results indicate improvements in the fuel economy of 39.6% and 43.6% for the vehicle with a nickel–metal hydride battery pack and the vehicle with a lithium-ion battery pack respectively. A hardware-in-the-loop application for motor-in-the-loop testing is also conducted to evaluate a permanent-magnet traction motor which is designed to replace the current induction motor. This study provides a design guideline and battery pack sizing for series hybrid powertrains in light-duty nontactical vehicles.