Study On The Coordinated Control For Mode-switch Of Parallel Hybrid Electric Vehicle

Control of dynamic process for HEV (hybrid electric vehicle) is becoming more and more important with the development of the R&D of HEV. The shifting processes among different modes and gears may cause vibration and make the ride feeling worse. To realize smooth power transfer during the dynamic process is one of the key technologies of hybrid electric vehicles.The dynamic process under mode-switch for PHEV (parallel hybrid electric vehicle) is investigated. This paper presents a coordinated control strategy, evaluating method, and a computer simulation study for analyzing the dynamic process.The dynamic performance of the power train is investigated first, including engine subsystem, electric machine subsystem, and the chassis. The evaluating method of coordinate control quality is introduced.This paper describes the whole modes of PHEV, and the mode-switch processes could be set into three parts, which are mode-switch in driving mode, mode-switch in breaking mode, and mode-switch between driving mode and breaking mode, based on different torque requirement.The coordinated control issue under mode-switch is mainly discussed. The changes of the engine, motor, transmission, clutch during mode-switch process are expounded. A detail dynamics analysis of HEV coordinate control is done. The coordinated control algorithm is presented and three representative mode-switch processes are investigated in detail.