Study Of Working Mode Of Hybrid Electric Vehicle And The Strategies Of The Sparation Clutch

The gradual deletion of oil resources and national regulations on vehicle emission of increasingly high demand led vehicle manufacturers to develop hybrid electric vehicle. Because large capacity battery is too hard to gain revolutionary headway in the near future, the development of pure electric vehicle is limited. The automobile enterprises focus on the development of HEV (Hybrid Electric vehicle) and it will play its advantages in a relatively long time.HEV is equipped with an engine (ICE) propulsion system and a motor propulsion system, according to the different working mode of the two systems, HEV can be combined with a variety of working mode, however, in order to achieve better driving performance, optimal energy consumption and emission performance. There are suitability mode-switching processes while vehicle running. However, the mode switching process may include engine start or quit of working state, engagement or separation of the clutch and the engine and the motor torque distribution, may cause the change of the running state of the system and the change of engine and motor target torque, If the control isn’t reasonable, it can cause transmission produce a lot of torque fluctuation, which causes a larger pulse on the whole vehicle. Therefore, the control of above dynamic process is one of the key technologies to promote the industrialization of HEV.Based on this, the main researches in this paper are as follows:(1) Analysis of the structural characteristics of the hybrid system, research dynamic equation model of hybrid electric vehicle and the mode of hybrid drive system, and according to the clutch state changing, the drive mode-switching process is divided into three types, so as to make following corresponding mode-switch control strategy.(2) Analysis of hybrid vehicle working mode division principle, the mode-switching conditions, engine and the motor target torque, mode switching strategy and coordinated torque control strategy. Take the typical switch processes as an example to do a detailed analysis of each stage, mode switching kinetic equation each of three kinds of mode switching,(3) Research the hybrid power system’s key component, the separation clutch, analysis it’s working principle, and the control strategy of the clutch engagement process and separation process of the mode-switching process, and based on the fuzzy control, complete the design of the separation of the clutch fuzzy controller.(4) In the MATLAB/Simulink environment, build a hybrid mode switching strategy model, torque distribution strategy model, and the separation clutch control strategy model, through the simulation of the mode switching process analysis, simulation results validate the control strategy proposed is effective.