Slip rings
Windings
Double-rotor
machine
Ordinary
machine
AC-DC
converter
DC-AC
converter
Battery
Carbon
brushes
Differential
Wheel
Wheel
Engine
Integrated doublerotor machine
Slip rings
Windings
v
AC-DC
converter
DC-AC
converter
Battery
Carbon
brushes
Engine
Differential
Wheel
Wheel
380
Alternative Fuels for Transportation
Figure 12.15
ECVT using two concentrically arranged double-rotor machines.
Figure 12.16
ECVT using integrated double-rotor induction machine.
is varying. Hence, the desired continuously variable ratio between engine
speed and wheel speed can be attained.
In order to reduce the system weight and size, the two machines can
be integrated into a single machine. The key is to share the outer rotor of
the first machine with the rotor of the second machine so that the stator is
placed concentrically around the outer rotor. Figure 12.16 shows the configuration of an integrated double-rotor induction machine (Hoeijmakers and
Ferreira 2006). It has the definite advantage of being highly compact and