Analysis of the Overall Propulsion System on Driving Cycles

2 Analysis of the Overall Propulsion System on Driving Cycles 

The main results of the experimental tests regarding the hard hybrid configuration on the R47 cycle are reported in Fig. 6.27a-c. The Fig. 6.27a shows the distribution of the power between FCS, electric drive, battery pack versus the cycle length. The output power of the fuel cell system is fixed at two constant values by 

The electric energy recovered during the regenerative braking phases can be evaluated for both cycles, as percentage of the energy entering the electrical drive, it results about 8 and 16% for R47 (Fig. 6.27) and R40 (Fig 6.28), respectively. 

The instantaneous efficiency of the stack and FCS are shown in Fig. 6.29 for R47 cycle in hard hybrid conhguration and in Fig. 6.30 for R40 cycle in soft hybrid configuration. According to the results obtained in steady-state operation, during the low load phases the stack efficiency reaches the value of about 0.7, whereas during the power variations required by the electric drive the efficiency decreases down to the lowest value of about 0.6, in correspondence with the most 

The values of efficiency obtained for the main components of the power diive by experimental measurements are reported in Table 6.6 for R40 cycle in soft and hard hybrid configurations. The evaluation of power train total efficiency takes 

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