Dual Mode Electric Infinitely Variable Transmission

The Power-Split architectures for Automatic Transmissions allow the mainstream of power to pass through a high efficiency planetary gears arrangement. The variator, which controls the overall gear ratio of the transmission but usually exhibits a lower efficiency, only sees a fraction of the power coming from the ICE. RENAULT carried out a systematic study of the possible Power-Split AT architectures in order to select the most flexible and efficient variator. Their conclusion is that an electric variator based upon two coupled electric machines, one working as a generator and the other working as a motor was probably one the of the best compromise considering all the existing technologies.