Engine-in-the-Loop Validation of a Frequency Domain Power Distribution Strategy for Series Hybrid Powertrains

This paper presents an engine-in-the-loop validation of a power management strategy for hybrid electric powertrains that splits the power demanded by driver between the engine and battery depending on the frequency content. In particular, a series hybrid electric powertrain is considered where the engine is a real 6.4L diesel engine and the rest of the vehicle, including the battery, generator, motors, vehicle dynamics, and driver, is modeled in computer. A networked engine-in-the-loop experiment is considered where the engine and generator constitute one site, and the rest of the system constitutes another site. This networked setup is used to compare the abovementioned power management strategy to a thermostatic strategy as the baseline. For the specific drive cycle considered, the proposed strategy yields about 12% increase in fuel economy, a performance that exceeds the previously reported purely model-based simulation results. In addition, an improvement in battery life can also be expected.