Sinisa Jurkovic, Global Propulsion System, General Motors
While it is safe to say that the certainty of vehicle electrification has never been so apparent, the debate on the appropriate level of electrification and appropriate system to get there is still ongoing and it’s likely to stay that way for the conceivable future. The customers are becoming more familiar and captivated with HEVs while their needs and desires in this space are evolving, hence driving the demand for a wider range of electrified vehicles including; BEVs (Chevy Spark), EREV (Chevy Volt 2), PHEV (Cadillac CT6), Fuel Cell etc. This talk focuses on electric machines for traction application, common key enabler of vehicle electrification. Specifically, we will discuss a range of electric machines designed and developed over the last decade in support of vehicle electrification at General Motors.
Although each application brings along its unique set of system and component level requirements and challenges, some characteristics and requirements are common across the entire portfolio. Specifically, for electric traction machines, some key common requirements are: Relatively high torque and power density, wide speed operating range, high efficiency in low to medium torque ranges over the large speed span, wide temperature operating range, high transient thermal capacity, reliability, excellent NVH metrics, mass manufacturability and ultimately, the cost. All combined constitute a tall engineering order by any measure and no single electric machine topology can meet it all across the application spectrum. At GM, over the years, we have designed and developed various electric machines, optimized for specific application needs and those will be the focal point of this discussion.