Design And Control Of A Novel Power-split Hybrid Powertrain

Plug-in Hybrid Electric Vehicle(PHEV),as a transition product from conventional vehicle to pure electric vehicle,has all the advantages of high efficiency,energy saving,low emission and long driving distance by coordinating the operations of engine and motor.Among all kinds of PHEV powertrains,the power-split hybrid powertrain can ensure high transmission efficiency,and completely decouple the relation between engine and wheels.Therefore,it has the biggest research value among all hybrid powertrain configurations.This paper presents dual mode(input-and output-split)hybrid powertrain with a single planetary gear set.Clutches are substituted for a synchronizer to achieve mode-shift.All possible topological schemes are enumerated,whose lever models are established.Then the kinematics analysis and power flow analysis combined with transmission ratio distribution under working conditions are applied to select the best schemes.With the goal of fuel economy and acceleration performance,two optimal schemes and two typical power-split powertrain are optimized by the backward simulation method.By comparing the fuel economy and acceleration performance of the four powertrains method above,the advantages of the two novel hybrid powertrains are verified.Finally,a rule-based energy management strategy for the PHEV installed the proposed powertrain is designed.The mode-shift rules in three cases of charge-depleting(CD)mode,rising stage of charge-sustaining(CS)mode and decline stage of CS mode are specified respectively,and the speed and torque allocation strategies in all powertrain modes are established.The forward simulation model is used to verify this energy management strategy.