Power management strategy for a novel hybrid electric bus with dual planetary gears

Hybrid electric vehicles with power split system have been widely used during recent years due to its huge potential to reduce the fuel consumption and enhance the drivability. This paper presents a novel powertrain architecture for a hybrid electric bus (HEB) based on dual planetary gear. The configuration and operating modes are described elaborately in this paper and a rule-based power management strategy is adopted to the HEB. Meanwhile, dynamic programming (DP) algorithm is also used as a benchmark to verify the effectiveness of this system. In order to validate the fuel-saving ability, both the rule-based and DP-based power management strategy are simulated based on the same typical driving cycle. As a result, the low fuel consumption achieved by DP verifies the effectiveness of this novel powertrain architecture. Moreover, the fuel consumption of the rule-based strategy is merely 11.29% higher than that on DP, which proves the feasibility of the rule-based strategy.