Environmental Engineering Reference
In-Depth Information
satisfied by the stack. In this test, the batteries mainly plays the role of recovering
energy during the regenerative phases, as evidenced by the negative values
reached by the battery and engine power curves. The energy recovered during the
regenerative braking phases results about 15% of the total energy entering into the
electric drive during the cycle. The data reported in Table
7.3
show that significant
differences are not observed in terms of efficiency values for this test with respect
to the experiment of Fig.
7.56
, in particular an efficiency value of 26% is calcu-
lated for the total power train.
a
b
1
0.9
0.8
0.7
0.6
0.5
1
7
13
19
25
31
37
43
49
55
61
67
73
79
Cell Number
Fig. 7.59 Hard hybrid procedure during R40 cycle. a Electric energy profiles instantaneously
exchanged by electric drive, battery pack, and FCS versus cycle length. b Histogram of individual
cell voltage during the steady state FCS working
