Environmental Engineering Reference
In-Depth Information
Simulation is used to determine ultra-capacitor pack sizing for engine cold
cranking. The worst case is cold cranking a compression ignition direct injection
(CIDI) engine (e.g. diesel engine) at
30
C. Such a simulation was performed in
ANSYS Simplorer using an ultra-capacitor model, solenoid model, permanent
magnet starter motor model, gearing and a simple engine friction and inertia model.
Figure 10.26 illustrates the simulated ultra-capacitor module voltage (a 6S
1P
3,000 F module) charged to 16 V and applied to the engine starter motor
for approximately 1.5 s. The starter motor is assumed to have a torque constant,
UC volts
Str_Mtr_Amps
16.00
2.52k
2.00k
15.00
1.50k
1.00k
14.00
500.00
13.00
0
-480.00
12.08
0
250.00 m
750.00 m
1.00
1.25
1.50
1.75
2.00
0
250.00 m 500.00 m 750.00 m
1.00
1.25
1.50
1.75
2.00
t
Engine crank speed (r/s)
24.80
20.00
15.00
10.00
5.00
-1.98
n
0
500.00 m
750.00 m
1.00
1.25
1.50
1.75
2.00
250.00 m
(a)
Battery
BOOSTCAPS
+
Starter
Engine
(b)
Isolating relay
+
5 A fuse
+
Required 10psi
oil pressure
switch
Cranking motor
Batteries
BOOSTCAP* module
-
(c)
Required relay
Figure 10.26 (a) Ultracapacitor voltage, ultracapacitor current and engine
speed, (b) Block diagram of ultracapacitor assisted battery for
engine cold cranking, (c) Architecture of ultracapacitor plus battery
for engine cold cranking
