Modeling And Simulation Of Power-Split Hybrid System Based On Ravigneaux Planetary Gears

With increasing oil price and mounting environment concerns, cleaner and sustainable energy solutions have been demanded. Limited by technology of the battery, pure electric vehicles still have a long way to go to take the place of The internal combustion engine (ICE) vehicle. HEV (Hybrid Electric Vehicle) has the advantages of both internal combustion engine and electric vehicles, so it’s becoming focus of study in the auto industry. Especially after Toyota Hybrid System appeared, power-split HEV based on the planetary gears has been a new hot area of research in hybrid vehicles.Computer modelling and simulation have been a important means in the design and development process of hybrid system, which can lead to a shorter development time and less development costs. Modes are used in the process of experiments study on actual system,, and its effective system design capability is particularly suitable for HEV energy management strategy and optimal design of powertrain, which is also suitable for vehicle analysis and simulation on HEV.In this dissertation, power-split HEV powertrains baesd on Ravigneaux planetary mechanism is studied. Bond Graph and The Lever Analogy are applied for the analysis of Ravigneaux planetary gears. And the best HEV system baesd on Ravigneaux planetary mechanism is selected. The designed operating modes of the HEV system are divided into three types, that are called EV mode, Parallel Fix Gear mode and CVT mode. Appropriate control strategies of the system are developed, on the basis of which, controlling system model is established.A Willians Line Model based on pantograph modeling method is built for internal combustion engine on Matlab/Simulink platform,electrical machine model based on efficiency map is also built. At the same time, the battery pack and its management model, models of other components are established. Finally, a modeling framework of the vehicle is formed. After that, an interactive simulation software of power-split HEV system is developed on Matlab/Gui, which lays the foundation for the simulation of the control of power-split HEV.In the same drive cycle, several factors that have great effect on vehicle’s fuel economy are explored, especially the impact of the the initial SOC values and the threshold of the parameters in and control strategy. While the Prius hev model based on single-planetary gears is built. The engine oil consumption and equivalent fuel consumption are compared between the two systems in three different drive cycles. The working regions of engine and motors on Map are also compared. The simulations reveal that power-split hybrid vehicle based on Ravigneaux planetary mechanism is better on vehicle’s fuel economy, which highlightings the advantages of the system under consideration, meanwhilethe availability of the control strategy is validated by simulation results.