複合動力電動車模式切換平順化策略

Abstract

本研究針對串並聯式複合動力車輛於不同模式切換之間，因動力輸出不連續產生之震盪，發展一套模式切換平順化策略，以提升乘車舒適性並延長動力系統使用壽命。本研究利用動力系統之物理觀念建立以運動方程式為基底之動力系統模型，作為研究模式切換策略的平台。首先針對欲模擬情境，展開模型中各子系統之功能需求，接著以Matlab/Simulink軟體建立各子系統並將其模組化以利後續研究擴充，在建立的過程中滾動式修正並添加需要功能，使其能更符合真實狀況地呈現本研究所需觀測之數據。透過將模式切換分為三個不同的階段，分別就各階段產生急衝度(Jerk)的原因進行探討，並針對各階段不同的原因設計改善策略，最後將各階段的策略整合，完成一套完整的複合動力車模式切換平順化策略。此外，本研究會探討動力元件、傳動軸與輪端在運動方程式中的機械係數，包含轉動慣量、阻尼係數與彈簧常數，針對不同子系統中各個機械係數之於動力輸出的急衝度的關聯性進行敏感度分析。

This research aims to develop a strategy to reduce the undersirable jerk of a hybrid electric vehicle during its’ mode switching due to the incontinuous torque output. By doing so, we can improve the comfortness of passengers and lengthen the lifespan of the powertrain. In this research, we will build a model of the powertrain in the form of equations of motion based on its physical concept, to form a virtual testbed for the mode switching smoothing strategy. First, we will define the circumstances we want to model to define the function each component’s model must accomplish. Then build the model with matlab/Simulink software, and divide the model into several subsystems to facilitate future upgrading of the system, and make the system meet the needs of the research by continuous modification and expansion throughout the model building process. By sorting the mode switching process into several phases according the the reason it generates undersirable jerk, we will design a strategy for each phase individually, and then combine them into a complete mode switching smoothing strategy. This research will also analyse the system’s sensitivity by studying the influence of the coefficients of the equations of motion of both the powertrain system and the driving shaft and wheel system on the jerk response and discuss how the characteristics of each mechanical elements affect the drivability of the car.