Generic Representations for Hybrid Powertrain Configurations

Hybrid electric vehicles (HEVs) utilize multiple power sources to minimize fuel consumption, which, generally, comprises one or two electric motors added to the conventional configuration. Based on the power flows from the sources to the wheels, the powertrain configurations are classified into three different types, such as series, parallel, and power-split. Although the classification is helpful for engineers to understand the layout of the system, it might not be useful for analyzing the operation of the system. This study proposes new classification concept, so that the powertrain configurations can be classified into two categories according to the operating mode, as either a variable type or a fixed type, which can be very practical for building mathematical models and analyzing the systems. The mathematical models are developed based on parameters characterizing the operations, and the modeling technique is tested in four real-world hybrid vehicles in order to see the feasibility. The new classification concept brings significant advantages for engineers who want to study hybrid systems because it is possible to accelerate the development process by reusing the generic models even for different powertrain configurations, which can be used for analyzing, evaluating, and optimizing the hybrid powertrain systems.