Thermal Study Of The Power Compound Transmission System For Deep Hybrid Electric Vehicle

Nowadays, we observe that the world concern is increasing about global cli-mate warming and green house effects. According to investigations by the Inter-national Panel of scientists for Climate Change (IPCC), the global climatewarming is mainly linked to the CO2emission. This is the reason why most ofindustrial companies start to limit their production of green house gas, and carindustries invest on making eco-friendly vehicles. The car makers in China arelooking for clean and green propulsion systems for new cars, and are now focus-ing on the use of electric motors.The electric energy to run those motors can be produced with none, or verylimited, CO2emission (nuclear power plants), what makes it very attractive.When the electricity is produced with coil power plant for instance, at least allthe CO2emissions are localized in the power plant, and its possible to make amass treatment of those CO2and green houses gas output, while it is impossibleto treat the output exhaust fumes of millions of cars. However full electric vehi-cles are faced to lots of technical problems by far with power batteries. There-fore, hybrid electric vehicle are of more energy intensity to run on either thermalor electric energy.GEELY Chinese Car Company is also concerned by the fast growing marketof hybrid vehicles, and is now developing its own hybrid electric vehicle. Thisthesis focus on the electric transmission system of this car, named GEELYMEEBS (Mechanical Electric Equivalent Balance System). This transmissionsystem is now a prototype, and this thesis is about creating a numerical thermalmodel of this system. Such a model will permit to try new hydraulics paths, aswell as new driving cycle simulation, before making a real prototype, which leadto time and money savings. To make this numerical model, we will use the software AMESim, which us-es the lump element theory to perform1D simulations. AMESim was firstly de-signed for car engineering multi domain simulations. Literature showed thatlump elements analysis are well adapted to simulate thermal-hydraulic systemsas well. This way, it fit the thermal study of electric transmission system forHEV we want to perform.In AMESim, we will develop a thermal model for the hydraulic circuits, theircorresponding fluids, the electric motors and power electronic units, heat ex-changer, pump and radiators. Then, we input in this numerical model severalexperimental values, which correspond to a performance of a New EuropeanDriving Cycle, done under different power control management strategies.We finally see that, under some assumptions, the model is well adapted toevaluate the thermal behavior of the electric transmission system, especially itspower electronics, ATF cooling fluid, and electric stator coppers. We will finallyreview the next evolutions of the numerical model to make it more accurate.