Energy storage technologies - Propulsion Systems for Hybrid Vehicles - page 474

Table 10.5 Vehicle attributes for battery-capacitor combination study

Attributes Performance targets

m v Vehicle mass 1,610 kg 0-60 mph accel. < 9.5 s

C d Drag coefficient 0.327 50-70 mph passing < 5.1 s

2.17 m 2

A f Frontal area Max speed 90 mph

R 0 Rolling resistance 0.008 kg/kg 50 mph for 15 min 7.2% grade

r r Wheel radius 0.313 m E-only range, H0 0 km

m glider Glider mass 1,053 kg E-only range, H20 32 km/20 mi

P acc Accessory power 500 W E-only range, H60 96 km/60 mi

The ESS is assumed to have the peak power and discharge durations defined in
Figure 10.28 and electric-only range targets of 0, 20(32) and 60(96) mi(km) as
noted. The maximum acceleration time, t m , will be taken as 10 s, and the electric-
only range time, t m E , is dependent on the specific fuel consumption (kWh/mi) of the
vehicle. In this analysis the specific fuel consumption is taken as 0.3 kWh/mi or
0.1875 kWh/km.

40

Launch
and
accel.

15

Electric-only range if applicable

0 t m

t m E

Figure 10.28 Energy storage system performance targets

For either case of direct parallel or independent power processor connection,
the capacitor storage system must deliver the amount of energy defined in (10.32)
to meet the launch and acceleration specification. The electric-only range will be
treated separately. The capacitor energy required is then

P pk t m ð 1 = 2 Þ t m g P b m b
3,600

E c - req ¼ ð J Þ ð 10 : 33 Þ

In (10.33) the capacitor system must deliver an amount of energy that is the
difference between the required energy and energy supplied by the battery. The
battery system is capable of delivering power:
P b ¼ g P b m b
E c ¼ g E c m c

(W, kWh) ð 10 : 34 Þ