Study On Planetry Gear Unit For Parallel Hybrid Electric Vehicle

In this thesis, a series of important problems such as kinematics, dynamics and vehicle main power components selection about single,double planetry gear unit for parallel hybrid electric vehicle(PHEV) which are investigated systematically.At the same time, simulation analysis of the steady state performance and dynamic performance is presented, and the analytical results can be helpful for determination optimum structure plan and perfection and formulation of control strategy.Firstly, structure characteristics of planetry gear unit for PHEV are analyzed and six kind of connecting relationship between three basic components of planetary gear unit and two power sources is put forward based on two freedom characteristic of planetary gear unit. The application of bond graph theory to planetary transmission system and theoretical basis for bond graph modeling and simulation are introduced, thus laid a foundation for performance analysis of planetry gear unit for PHEV.Based on the requirement of power synthesizer for PHEV and the theoretical analysis of planetry gear unit for PHEV, such as the transmission ratio, power flow and transmission efficiency, parameter relationship at steady operation condition, the comparison between six kind of transmission scheme is carried out so as to put forward optimum structural plan.Furthermore, simulation analysis of the steady-state performance is presented. At the same time, optimum coupled power operating point of two power sources for PHEV at steady operation condition is put forward from synthesis of dynamic.Based on bond graph theory, dynamic model of planetry gear unit for PHEV with different operation model is established and correlative system state-space equations is run with considering the damping,the stiffness and system rotational inertia. Furthermore, simulation analysis of the dynamic performance is presented and optimum coupled power operating point of two power sources for PHEV at dynamic operation condition is put forward from synthesis of dynamic.On the basis of the above work, synthetic performance analysis of planetry gear unit for PHEV is made and some design principles for planetry gear unit for PHEV is put forward starting from original machinery attribute of the planetry gear unit.Finally, the control strategy,main power components selection and principles for matching parameter of PHEV is given out starting from actual situation of this thesis. Based on ADVISOR2002 simulation software, the driving system simulation models are established and simulation analysis is presented.