Environmental Engineering Reference
In-Depth Information
engine when used in conjunction with a torque splitting device. The governing
equation for the transmotor, assigning
w
r
to the rotor and
w
s
to the stator, is
P
e
¼
T
r
ð
w
r
þ
w
s
Þ
ð
2
:
6
Þ
where
P
e
is the electric power at port 3 of the transmotor. Ports 1 and 2 are the rotor
and stator mechanical connections. The physical arrangement of this configuration
is shown in Figure 2.36 where clutches are used to connect and disconnect the
engine and driveline so that all operating modes can be met. Clutch 1 connects or
disconnects the transmotor rotor from or to the engine. Similarly, clutch 2 connects
or disconnects the transmotor stator from or to the engine. Clutch 3 is used to lock
the transmotor stator to the chassis. The transmission input shaft is permanently
connected to the gearbox input shaft.
2.6.2 Petrol electric drivetrain
A concept that has been explored for some time is the work of P. Jeffries in the UK
[26] that he refers to as petrol electric drivetrain (PEDT). The PEDT frees the M/G
stator assembly to rotate so that both rotor and stator are free to move. Doing so
permits the stator to function as a flywheel and accumulate mechanical energy from
the drivetrain and store it in the same form. This concept of storing and delivering
the energy in the same form in which it is being used has considerable merit. For
example, it has already been pointed out that ultra-capacitors make good storage
systems because electric energy is stored in the same form in which it is being used.
Figure 2.37 illustrates the PEDT concept.
The ICE in Figure 2.37 couples to the PEDT electric machine stator/flywheel
through an automatic clutch, an OWC and speed increasing gears. When the engine
Inverter
Batteries
I
CE
Electrical
machine
Gears
Wheel
PEDT system configuration
Figure 2.37 Mechanical energy storage and consumption in flywheel ( from
Reference 26)
