Kapadia, J., Kok, D., Jennings, M., Kuang, M. et al., "Powersplit or Parallel - Selecting the Right Hybrid Architecture," SAE Int. J. Alt. Power. 6(1):68-76, 2017, doi:10.4271/2017-01-1154.
The automotive industry is rapidly expanding its Hybrid, Plug-in Hybrid and Battery Electric Vehicle product offerings in response to meet customer wants and regulatory requirements. One way for electrified vehicles to have an increasing impact on fleet-level CO2 emissions is for their sales volumes to go up. This means that electrified vehicles need to deliver a complete set of vehicle level attributes like performance, Fuel Economy and range that is attractive to a wide customer base at an affordable cost of ownership.As part of “democratizing” the Hybrid and plug-In Hybrid technology, automotive manufacturers aim to deliver these vehicle level attributes with a powertrain architecture at lowest cost and complexity, recognizing that customer wants may vary considerably between different classes of vehicles. For example, a medium duty truck application may have to support good trailer tow whereas a C-sized sedan customer may prefer superior city Fuel Economy. This difference in attribute wants can drive the need for different electrified architectures. Here, two commonly used Hybrid and Plug-in Hybrid Electric Vehicle architectures can be distinguished: Powersplit and Parallel configurations.This paper studies the design differences between these Hybrid architectures and the intrinsic attribute advantages that one can provide over the other. Subsystem design criteria, including sizing of key components is considered. The two approaches are compared for a specific vehicle assumption for attributes and normalized cost.