PSI - Issue 12

Francesco Mocera et al. / Procedia Structural Integrity 12 (2018) 213–223 Author name / Structural Integrity Procedia 00 (2018) 000–000

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Fig. 8: Electra 21: first full electric prototype of a self propelled vertical feed mixer wagon

between the Department of Mechanical and Aerospace Engineering (DIMEAS) of the Politecnico di Torino and the Italian company Supertino Srl, led to the birth of Electra 21 shown in Fig. 8.

6. Conclusions

In this work, the performance analysis on a self propelled vertical feed mixer wagon is shown. In collaboration with the Italian company Supertino Srl the daily activities of such a machine were monitored reading data sent from the engine over its CAN BUS network. This study highlighted the critical aspects of the main activities of this kind of machines. Although slight di ff erences between users, these machines are characterized by a high repetitiveness of the working operations. The driving activities are usually restricted to a limited area around the farm. The main mechanical activities of the machine are characterized by a constant load profile which usually do not exceed the 70% of the total installed power. In some cases, as for the silage loading and driving activities combined with the mixing one, the amount of requested power may saturate the total available installed power. This condition has two important consequences: the first one is to increase fuel consumptions and thus pollutant emissions related to a specific activity; the second one is related to the durability of the power unit which do not benefit of long period of high load work. From this point of view, a certain degree of electrification of the current power unit would optimize the performance. The experimental data gathered were used to identify the working cycle of the considered vertical feed mixer wagon and to design an electrified architecture of the traditional machine. Two main solutions with a di ff erent hybridization factor were considered. The electrification of the hydraulic power path would certainly have benefits on fuel consumption and pollutant emissions, allowing for a downsizing of the thermal engine. Moreover, the more stable operating conditions would help durability of the thermal unit and its auxiliaries which would work more frequently around their nominal conditions. The study highlighted also the possibility of a full electric conversion of the traditional architecture which was then designed and built with the italian manufacturer.