ABSTRACT The paper focuses on the advantages of the diesel electric traction applied to military vehicles. In recent years electric cars developed mainly to reduce the dependence on fossil fuels and cut down the emissions. The reduction of fuel consumption, important for civil vehicles above all to reduce emissions and to lower costs, is important also for the military in order to increase vehicle autonomy. In addition, the interest for hybrid electric military vehicles is linked with vehicle packaging flexibility, on board power generation and stealth potential related to their abilities of silent movement. Among many possible layouts the optimum is considered to be hub mounted drive motors in each wheel [ 1]. This study shows the development of a demonstrator of an hybrid electric 4×4 military vehicle. It was carried out for a future extension of the technology to a 8×8 armoured vehicle. Starting from the general layout of the hybrid system all components of the demonstrator are described and the whole control logic is discussed. INTRODUCTION The main aim of this work was to develop a series hybrid electric 8×8 vehicle. In order to reduce development costs it was carried out on a 4×4 commercial vehicle. The former request that it had to satisfy was that would have been possible to mount on it the same 20″ wheels of the 8×8 armored vehicle. Figure 1. exploded drawing of the wheel used on the 8×8 vehicle and on 4×4 demonstrator. The latter was that the commercial vehicle should be similar to the armored vehicle in terms of track, weight per axle (if necessary we can take on some ballast) and power of the internal combustion engine. GENERAL DESCRIPTION OF THE LAYOUT The general layout of the demonstrator will be described. In particular we will focus not only on the mechanical layout but also on the power electric, electric supply and CAN network circuit diagrams. In order to simplify the assemblage the cooling system, the traction inverters, the AC/DC and DC/DC inverters and the control units (PMS, BMS, TMS and VMS) were placed in the bed of the truck used to build the demonstrator( Figure 2). Design and Development of an In-Hub Motors Hybrid Vehicle for Military Applications2010-01-0659 Published 04/12/2010 Mauro Velardocchia and Enzo Rondinelli Politecnico di Torino Copyright © 2010 SAE InternationalDownloaded from SAE International by Univ of California Berkeley, Saturday, July 28, 2018Figure 2. Electric Layout of the Demonstrator The traction system is made of 4 hub mounted drive motors, one for each wheel. The drives and the diesel generator will have power converters to provide/draw power from a DC bus. Power flow will be managed by the vehicle management unit across a controller area network (CAN) bus. Improvements in fuel consumption are realized through efficient power management and electrical regenerative braking. Pulse acceleration is achieved by using the power generators and energy storage in series. The packaging of electric drive components gives control of overturn angle; individual wheel control can provide improved traction, and skid/dual steering can improve turning circle. DIESEL ENGINE AND ALTERNATOR Was estimated that for the 4×4 demonstrator vehicle we need to generate on board 250 kW of electric power while the internal combustion engine (ICE) supplies its maximum power in a range between 1900 and 2300 rpm. It was chosen a layout where the electric generator (GEN) is directly coupled with the ICE and provides energy to a three-phase converter IGBT. The converter works as a rectifier “switching” (RS) that through a PWM technique adjusts the outgoing sinusoidal current so that it is in phase with the electromotive force of the generator itself. Figure 3. Power Generation electric layout for the 4×4 demonstrator Because of the predicted operational ambient conditions of the system (from −19°C to +49°C) both the generator and the IGBT converter were realized with IP65 protection level and equipped w