Design And Bench Test Of A Hybrid Electric Vehicle Powertrain

With the continuous development of human society and the growing energyconsumption worldwide, human beings are facing the facts that global oil resources aredepleting and environmental pollution are increasing serious. Automotive manufacturersworldwide have been striving for decades to produce vehicles which satisfy customers’requirements at minimum cost. Many of their concerns are on driveability, fuel economy,road performance and emission performance. Hybrid electric vehicle (HEV) is one ofthe most promising alternatives to a conventional engine-powered vehicle whichsatisfies increasing customer requirements mentioned above.Hybrid power transmission system is a core part of the hybrid electric vehicle. Inthe thesis, parameters matching were made basing on the analyzing of HEV powertransmission system’s structural and performance characteristics. The test bench wasbuilt and two bench tests were performed. The main contents of the thesis are as follws:①Taking a prototype vehicle as reference, parameters of the power performance,fuel economy, road performance were designated. Accoding to the design requirementsand the structural features of this HEV powertrain, parameters matching design of itsparts, including the engine, motor/generator, battery pack, the planetary mechanism andthe ratio computation of main reducing gear, were completed.②According to the design requirements, functional tests of parts and vehicle weredone on the HEV test bench. Combining with the design principles and objects, theoverall system scheme of the test bench was determined.③Bench tests that the HEV was driven by ISG motor or engine separately,parallel driven by the two together and ISG motor works as generator were performed.The test results verify all these functions and show that the powertrain can meet all theperformance requirements.④The functional tests of electromotor starts engine were performed, and all theresults indicating that the ISG motor can satisfactorily start engine with different clutchpreload. The starting time of engine was declining with increasing preload of clutch,which achieved the design goal that the starting time should less than0.5second.⑤The bench tests of engine starting while the vehicle was running wereperformed, and three sets of test plan were put forward. On the basis of analysis resultsof these tsets, revised test plan and the test were made, which confirmed the influence elastic suspension system exerts on test results. The satisfactory results were obtainedwhich provided a basis for test bench improvement and the study of HEV.