Page - 13 - in Hybrid Electric Vehicles

4.2. Loading power The driveline architecture in work vehicles can be electrical, hydraulic, and/or mechani- cal. Moreover, the loading power can be hydraulic or electrohydraulic depending on the vehicle topology architecture. Many work machines have some hydraulic actuators to be controlled, a big difference between a passenger car and a heavy-duty vehicle. In a full hybrid vehicle, for example, the hydraulic power for loading the bucket is supplied by the hydraulic pump, which can be powered by the ICE or an electric motor (EM2). The second ratio (µ2) of the hybridization factor for heavy-duty vehicles can therefore be defined as follows: µ 2   =  P e m 2 _______ P e m 2 + P ICE (3) In the automotive industry, the power of the internal combustion engine is mainly used for the handling of the vehicle, and other functions (such as air conditioning) may be neglected in a first order assessment hybridization. In a work machine, the power of the internal com- bustion engine can be used for both driving operations for loading activities. In particular, it is observed that the power required to move loads or to carry out excavation work is of the same order of magnitude of power required to move the vehicle. So, the design of a hybrid working vehicle must take into account the power requirements of the working cycle with particular reference to the types of equipment that can be connected to the arm or blade of the machine. In the present work, in order to define a hybridization factor that allows com- paring the many hybrid applications in the construction and agricultural machinery sector is the hypothesis that the power can be conventionally comparable between driving and loading is used. According to the previous statement and combining the two ratios expressed in Eqs. (2) and (3), the hybridization factor for heavy-duty work vehicles can be defined as follows: H  F WV   =  1 __2( µ 1 + µ 2 ) (4) Hybrid architecture Series Parallel Series-parallel Driveline powered by ICE No Yes Yes Driveline powered by EM Yes Yes Yes Loading devices powered by EM No Yes Yes Loading devices powered by EG Yes No Yes Loading devices powered by ICE No Yes Yes Table 2. Architectures of hybrid construction and agricultural machinery (HCAM). Trends and Hybridization Factor for Heavy-Duty Working Vehicles http://dx.doi.org/10.5772/intechopen.68296 13