Energy Management and Cooling of the Front Axle in a Sport Battery Electric Vehicle

From July 2022, I had the chance to work as an intern for the FPT Industrial Italy company, where I was able to develop my master's thesis project. FPT Industrial is a brand of the Iveco Group company that specializes in the development, manufacture, and marketing of propulsion systems intended for use in marine, on- and off-road, and power generation applications. Battery electric vehicles (BEVs), which have a more efficient driveline than internal combustion engine (ICE) vehicles, are in high demand because they have no tailpipe emissions. A functional and adaptable cooling system for a vehicle's driveline is necessary since all powertrain types, whether conventional or electric, have inherent inefficiencies. Inefficiencies can cause heat loss and raise component temperatures. An improper temperature interval can degrade the performance of the transmission. In this thesis, the electrified cooling system for the front axle of a sport car is built using 1D CFD system modeling in the software GT-Suite. GT-Suite is a top 1D multi-physics CAE system simulation tool that can be used in a wide range of industries and applications. The primary goal of the project is to make a model of the thermal management system of the e-axle, which includes a heat exchanger, an electrified oil pump, an oil filter, an electric motor, a 2-step gear speed reduction of the transmission, and the lubricant and coolant circuits. By investigating the effects of the various boundary conditions, especially by analyzing critical operating conditions, it provides a mechanism to adjust the temperature and rate at which oil circulates through the electric driveline, aiding in the cooling and lubrication of the transmission. Overheating of the oil or too much thick oil can cause components to seize up, so it is crucial to keep the lubricating oil between the right thresholds of temperatures. The cooling system model for the front axle was developed as the first step of the project. The pressure data from the simulation model was then compared to the results of the experiments in order to confirm the geometry of the oil and coolant circuit components. With the available supplier data and the ability to assess the accuracy of the modeling in GT-Suite, it has been critical to regulate and calibrate the electric motor and electrified oil pump speed as well as act on the pipe and orifice characteristics. The created model can be used to help with different thermal analysis tests. As the thermal regime changes over time and depends on factors like the load case, including the torque and speed of the electric motor and drive gears, and to see how the cooling system responds to changing boundary conditions, data from two distinct experimental tests have been taken into consideration. In the first sort of experiment, known as the spin loss test, three different steady-state oil temperatures—40 °C, 80 °C, and 120 °C—were considered. In this test, the actual electric motor was replaced with a dummy motor, while speed and torque were all applied and controlled from the output shaft of the differential. In the second experiment design, the brake torque controlled the actual electric motor while the output shaft of the differential received a resistive torque to control the speed of the electric motor shaft. Additionally, in both tests, the ECU adjusted the speed of the electrified oil pump based on the temperature of the oil sump. The results show that the oil temperature in the transmission remains within the ideal range. Also, co