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

resolved, and also believe that the cost of power electronics cannot be reduced as dramatically as

claimed. Nevertheless, these claims suggest there may be a potential for significant cost reduction

beyond even the aggressive goals of motor manufacturers.

OTA’s vehicle price analyses for EVs and hybrids accepts the motor manufacturers’ claims, but

not the more aggressive DOE research goals, as the high-frequency motor concept has yet to be

demonstrated in a practical application.

The weight of an EV-type induction motor and controller has the following relationship to
output power:

Weight (kg) = 1.0 * Peak kW + 14

based on Westinghouse motor weight data. The weight of a 100 HP motor is remarkably similar
to the weight of a modem OHC 4-cylinder engine (dressed) that provides 50 to 55 HP/L. PMS
motors could weigh about 20 percent less, while the high frequency induction motors discussed
above could possibly weigh 35 percent to 40 percent less than the weight indicated above.

If a motor with 30 percent lower HP is selected for equal performance, then weights for

an induction motor electric drive are about 25 percent lower than the weight of the IC

engine. In addition, elimination of the transmission results in a weight saving of about 70

lbs. These weight estimates are based on actual data on prototype motors and should be

representative of future motor/controller weights for EVs.

As noted earlier, the efficiency of the electric motor and controller, averaged over the FTP city
and highway cycles, can be very low. Currently, many EVs have reported efficiency for the
motor/controller in the 75 percent range on the city cycle and about 80 to 82 percent on the
highway cycle. Highly optimized prototypes have improved this efficiency to about 80 to 82
percent on the city and 80 to 90 percent on the highway. As noted, the higher performance
requirements lead to lower efficiencies at city speeds. In this report, the efficiencies obtained by
operating prototypes have been used to model commercial EVs and hybrids in 2005. By 2015, it
is possible that efficiency could increase by another 3 to 4 percent, owing to reductions in losses
in the power electronics and reduction of windage and eddy current losses in advanced motor
designs. Such improvements are highly speculative, and alternative scenarios with and without
these improvements are examined in the vehicle evaluation.

OTHER ENGINE AND FUEL TECHNOLOGIES

Overview

Numerous engine and fuel technologies have been suggested as powerplants and power sources
for the future In general, most of the alternative fuels, with one exception, are hydrocarbon fuels
ranging from natural gas to biomass-derived alcohol fuels, and most of these are being used
commercially in limited scale in the United States. Although these fuels can offer significant