Advanced Automotive Technology: Visions of a Super-Efficient Family Car

TABLE 3-13: Subjective Rating of Different Motors

for EV Use

Drive System With

DC-motor, AC induction

Feature separately excited PMS-Motor motor

Maintenance o^22

Efficiency o^31

speed limit o^23

Volume o^32

Weight o^32

Maximum torque^322

Moment of inertia o^33

Allowed rotor temperature o^02

Cooling possibilities o^32

Complexity of electronics 3 0 1

Torque control^331

National power limitation^330

Installed inverter power^301

Electromagnetic field loss^301

Rotor losses o 3 0

Excitation losses o^31

Field weakening^302

Slip rings, brushes o 3 3

Stator winding simplicity^132

Centrifugal rotor bandage^133

Power factor 3 2 1

Temperature dependence^303

Stability of magnets^303

cost of magnets^303

Construction simplicity^113

Automatic mass production 1 1 3

Tooling cost o^03

0 = poor

1 = average

2 = good

3 = excellent

KEY: DC= direct current; PMS = permanent magnet synchronous; AC = alternating current.

SOURCE: Daimler-Benz.