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The Cadillac CT6 plug-in hybrid electric vehicle (PHEV) power-split transmission architecture utilizes two motors. One is an induction motor type while the other is a permanent magnet AC (PMAC) motor type referred to as motor A and motor B respectively. Bar-wound stator construction is utilized for both motors. Induction motor-A winding is connected in delta and PMAC motor-B winding is connected in wye. Overall, the choice of induction for motor A and permanent magnet for motor B is well supported by the choice of hybrid system architecture and the relative usage profiles of the machines. This selection criteria along with the design optimization of electric motors, their electrical and thermal performances, as well as the noise, vibration, and harshness (NVH) performance are discussed in detail. It is absolutely crucial that high performance electric machines are coupled with high performance control algorithms to enable maximum system efficiency and performance.

A permanent magnet synchronous motor (PMSM) motor is used to design the propulsion system of GM’s Chevrolet Bolt battery electric vehicle (BEV). Magnets are buried inside the rotor in two layer ‘V’ arrangement. The Chevrolet Bolt BEV electric machine rotor design optimizes the magnet placement between the adjacent poles asymmetrically to lower torque ripple and radial force. Similar to Chevrolet Spark BEV electric motor, a pair of small slots are stamped in each rotor pole near the rotor outer surface to lower torque ripple and radial force. Rotor design optimizes the placement of these slots at different locations in adjacent poles providing further reduction in torque ripple and radial force. As a result of all these design features, the Chevrolet Bolt BEV electric motor is able to meet the GM stringent noise and vibration requirements without implementing rotor skew, which (rotor skew) lowers motor performance and adds complexity to the rotor manufacturing and hence is undesirable.

The effect on vehicle performance of extending the constant power operating mode of electric drive motors for electric and hybrid vehicles is presented in this paper. Modern electric and hybrid vehicle designers have the selection of several technologies to choose from when selecting an electric drive motor. Each motor technology exhibits a particular torque vs. speed characteristic. Many of these technologies, most notably the switched reluctance machine, have capitalized on iron and copper utilization, extending their useful speed range. However, the extended speed capabilities of these motor drives have vehicle performance consequences. It is presented that vehicle performance is affected by changing the torque-speed characteristics of the drive motor. The extended constant power speed range motor can have smaller rated power than otherwise but suffer high speed passing performance.

In this paper, the configuration of a parallel hybrid vehicle, called electrically peaking hybrid (ELPH) vehicle is introduced. Several operation modes of the engine and electric motor and different control strategies are analyzed. The results show that, with proper selection of the drivetrain parameters, the vehicle can satisfy the urban and highway driving with a small internal combustion engine, a small battery pack and a single gear transmission. Moreover, the vehicle does not need to charge the battery pack from the electricity network for keeping its battery SOC at a reasonable level.

The operation of an electrically peaking hybrid vehicle (ELPH) can be divided into two basic modes. • Constant or cruising speed mode in which a small internal combustion engine (ICE) is used to power the vehicle. • Peak power mode in which the combination of an electric motor and ICE is used to supply peak power for acceleration and limited-duration steep hill climbing of the vehicle. A method, by which the engine size and the speed reduction ratio from the engine to drivewheels can be developed based on the cruising mode, is presented in this paper. The electric motor power rating and the motor gear ratio to the drive wheels can then be determined, based on the acceleration and gradeability. The results show that a simple single-gear transmission would be a good selection for overall performance.