424 Auto Electricity and Electronics
climate control system. However, the blower forces outside
air through the battery pack enclosure and then forces this
air out of the vehicle. The hybrid ECU and battery tempera-
ture sensor control the operation of the blower motor.
Hybrid Motor-Generator
A hybrid motor-generator functions as both a power-
ful traction motor and as a high-energy alternator in the
vehicle’s power train. The hybrid motor-generator(s) can
have several functions:
❑
Help to power the drive train and propel the vehicle.
❑
Recharge the HV battery pack.
❑
Crank the internal combustion engine.
❑
Help to slow and stop the vehicle.
The basic parts of a motor-generator include:
❑
Motor-generator armature—a set of permanent mag-
nets mounted inside a steel segmented disc.
❑
Motor-generator stator—a set of stationary coil wind-
ings wrapped around iron cores.
❑
Motor-generator housing—holds the stator assembly
in place around the armature.
When consuming electricity as a motor or producing
electricity as a generator, the motor-generator armature spins
inside a set of electrical coil windings. See Figure 22-7A.
The motor-generator stator is a set of electromagnets
arranged in an array around the motor-generator armature,
Figure 22-7B. Electrical energy can be consumed or pro-
duced by the motor-generator stator.
The motor-generator housing allows the motor-generator
to be fastened to the rear of the engine, inside the transmission/
transaxle, or in the rear drive axle assembly, Figure 22-7C.
When assembled, Figure 22-7D, the motor-generator
armature spins in close proximity to the stator assembly.
Motor-Generator as a Motor
A hybrid motor-generator is usually a synchronous,
AC, permanent magnet, brushless design. There are no
electrical windings in the armature and no electrical con-
nections to it. The permanent magnet design improves reli-
ability over DC motors that have windings, which can fail.
The term synchronous means the rotation of the arma-
ture is synchronized or timed with the three-phase alternating
current entering the stator or coil windings. The three-phase
Figure 22-7 Study this simplifi ed drawing of a hybrid motor-generator assembly. A—The armature is a steel ring with permanent
magnets imbedded in its outer diameter. B—The stator is made up of sets of windings wrapped around iron cores. C—The motor-
generator housing holds the stator windings stationary. D—When assembled, the armature and stator form an assembly that can
serve as a high-torque motor or a high-energy generator.
Permanent
Magnets
A
C
B
D
Armature
Motor-Generator
Housing
Stator
Coil Windings
Iron Cores
Armature Spins
inside Stator