Page - 15 - in Hybrid Electric Vehicles

In the case of hybrid wheel loaders in series from the transformation of mechanical power into electrical and drive of the electric motor can also be done with a battery pack reduced but the generator and the electric motor need to be manufactured in terms of maximum power demand. The presence of the battery pack can allow to better manage the power demand peaks without the need to over-dimension the motor ICE [114, 115]. In literature, the hybrid drive train in the series has been applied mainly in large tonnage hybrid wheel loader. In 2009, Caterpillar came out with the first electric hybrid bulldozers. The Caterpillar D7E model is within the range of medium dozers and replaced the traditional model D7R [94]. The company claimed an increase of productivity and a reduction in fuel consumption up to 24% over the conventional model [94]. The driveline architecture is of the series electric hybrid type, as described in Figure 6, with the electric motors powered directly from the inverter but having the peculiarity to be directly charged from the ICE without any accumulation system. Model Type of vehicle Driveline Loading and working system Energy storage Caterpillar—D7E Dozer Series Conventional None Volvo—L220F Hybrid Wheel loader Parallel Parallel Battery Mecalac—12MTX Hybrid Articulated loader Paralell Paralel Battery John Deere—644K Hybrid Wheel loader Series Parallel None Merlo—TF 40.7 Hybrid Telehandler Series Parallel Battery Claas—6030 Hybrid Telehandler Parallel Conventional Battery Kobelco SK200H Hybrid Excavator Conventional Series Battery/capacitors Komatsu—HB215 LC-1 Excavator Paralel Parallel Supercapacitors Table 3. Hybrid working vehicles and their architectures. Figure 6. Working vehicle with series hybrid configuration. Trends and Hybridization Factor for Heavy-Duty Working Vehicles http://dx.doi.org/10.5772/intechopen.68296 15