Electric Traction Motors for Cadillac CT6 Plugin Hybrid-Electric Vehicle 2016-01-1220

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. Specifically, key challenges toward that goal are inverter voltage utilization, for maximum power capability and accurate current control for torque production. We focus of on the specific challenges in controlling induction machines where the leading requirement form the machine design side to lower leakage inductance has negative ramification on the controllability of the machine.