Power Split Supercharging: A Mild Hybrid Approach to Boost Fuel Economy

Abstract

This work studies a novel low voltage (<60 V) hybrid system that supports engine boosting and downsizing in addition to start-stop, regenerative braking, and constrained torque assist/regeneration. The hybrid power split supercharger (PSS) shares a 9 kW motor between supercharging the engine or providing hybrid functionalities through a planetary gear set, a brake and a bypass valve. The PSS operation is limited to only one of the parallel hybrid or boosting modes at a time, necessitating a highly optimized decision making algorithm to select the device mode and power split ratio. In this work an adaptive equivalent consumption minimization strategy (A-ECMS) is developed for energy management of the PSS. The A-ECMS effectiveness is compared against a dynamic programming (DP) solution with full drive cycle preview through hardware-in-the-loop experiments on an engine dynamometer testbed. The experiments show that the PSS with A-ECMS reduces a vehicle fuel consumption by 18.4% over standard FTP75 cycle compared to a baseline turbocharged engine, while global optimal DP solution decreases the fuel consumption by 22.8% compared to baseline.

Development of an Optimal Power-Distribution-Management Algorithm for Four-Wheel-Drive Electric Vehicles

“…In the case of hybrid electric vehicles, although there is relatively less concern regarding the range compared to pure electric vehicles, the interior space of the vehicle is reduced, in addition to weight increase, due to the increased number of complex structures and parts. Hence, technology that efficiently utilizes energy is recognized as a critical research area in the development of ecofriendly vehicles [4][5][6].…”