Environmental Engineering Reference
In-Depth Information
210.0
150.0
100.0
50.0
0
-50.0
-100.0
-137.0
0
500.0
1.00
1.40
(a)
t
155.2
150.0
140.0
137.7
0
500.0
1.00
1.40
(b)
t
Figure 4.13 Validation of active parallel simulator with battery only active
combination. (a) Battery current corresponding to UDDS drive
profile and (b) battery model terminal voltage response to UDDS
4.2.3 Step 3
In this section, the BEV, a Miata sports car, is simulated over the UDDS drive cycle
with lithium ion pack only and then with decoupled power and energy provided by
the active combination. A proprietary EMS implemented as a dynamic set point
control of ultra-capacitor SOC was used. The vehicle is fully electric so the battery
will undergo charge depletion while the ultra-capacitor will approximate charge
sustaining under dynamic SOC control. Nominal set points for SOC are 0.6 for the
battery and 0.83 (135 out of 148 V) for the ultra-capacitor pack. The battery pack
model is configured to accept any initial SOC set point to evaluate its performance
during various SOC levels. An alternative is to repeat the UDDS cycles to view the
battery performance over its complete capacity range.
Note the hand-off in supporting load current in Figure 4.14(c) at approximately
200 s from the ultra-capacitor to the lithium ion pack as the ultra-capacitor voltage
goes below half-rated voltage. In this region and thereafter the dynamic set point
