Study On The Fault Diagnosis And Fault Tolerant Strategy Of Hybrid Electric Vehicle

Energy source shortage and environmental pollution arising from automobile industry have been given more and more attention all over the world. Development of new type motor vehicle with low energy consumption and emission is being under-way by world-famous automobile industry and research institution, which is encouraged by government policy. Hybrid electric vehicle arises at the historic moment, which can combine the goodness of traditional combustion vehicles and electric vehicles. HEV also can achieve the goal of low energy consumption and low emissions, which make it to become the hot point for the development of global electric vehicle, and tend to be the trend.The Ministry of Science and Technology of China has also set the development of HEV, and HEV components as one of the most important sub-projects in the 863 Program. Jilin University shoulders two projects of the 863 Program. One is the development of hybrid electric transit bus, together with the research and design center of FAW; another one is the development of control system of hybrid electric transit bus power train, alone.The thesis chooses liberation brand hybrid electric transit bus which has two axes paralleled structure as investigative object, studies on the fault diagnosis of the power system and fault tolerant strategy of the hybrid control unit.Firstly, on the basis of studying the HEV components, the paper analyzes the fault type of the components, fault diagnosis technique. The thesis also studies on the fault type of CAN BUS and put forward the solution. At the same time, the thesis has finished the analysis to the fault mode of hybrid power system, the fault diagnosis for the HEV components and found the fault tolerant control strategy of HCU.Secondly, the dissertation analyses the control strategy, model and drive mode of parallel hybrid control unit which has no fault diagnosis and fault tolerant strategy. Based on the analysis, the thesis uses software MATLAB/Simulink and Stateflow builds the control strategy models which include the fault diagnosis and fault tolerant modules of engine, AMT, motor, battery and regenerative brake system, and then expounds the control strategy when the components of hybrid power system is failure.Lastly, the thesis introduces the application of the dsPACE real-time simulation technology in HEV control system, and explains the virtual test significance in the development of hybrid electric technology. The paper expounds the hardware and software of the virtual test, chooses dsPACE1005 as vehicle simulator, chooses dsPACE1401 as HCU simulator, and connects them with CAN BUS to establish the virtual test frame. The thesis simulates engine, AMT, motor and battery fault signals separately during the virtual test and simulates the hybrid brake system by Simulink off-line software. Under analysis of the virtual test and off-line simulation results, the fault tolerant strategy is feasible.