Integration and System Tests of the Ford/General Electric AC Electric Drive System

An advanced alternating current electric drive system, discussed in this paper, is being developed by the General Electric Company for Ford Motor Company's “Advanced Electric Vehicle Powertrain Effort,” which is a major element of DOE's Single Shaft Electric Propulsion System Program.

The integrated transaxle consists of an oil-cooled 50 hp ac induction motor mounted within a 2-speed transaxle. Direct current from the nominal 204 V battery pack is converted to variable frequency, variable voltage 3-phase ac current by a liquid-cooled transistor inverter. A custom-designed inverter motor controller, containing two 8751 microcomputers plus analog and digital circuitry, translates torque commands from the vehicle microcomputer-based controller to the inverter transistor base drivers that turn on/off power Darlington transistors at appropriate times.

After a review of the electric drive system ratings, details of the transistor inverter will be presented. Control strategy and controller design will be summarized. Electric drive integration and system test results will be presented.