Design of a battery pack model to test a Battery Management System in Hardware-In-The-Loop environment

With the increasingly common use of high-voltage traction systems, whether for hybrid or full-electric powertrains, the automotive industry needed useful tools to study batteries and the electronic control units (ECU) associated with them. The aim of this thesis work, carried out at Kineton S.r.l., is to test a Battery Management System (BMS) in a Hardware-In-The-Loop (HIL) environment so that its behaviour and connections with a simulated battery pack can be analysed. After the BMS was selected, the electrical schematic and datasheet were studied to create a configuration between the device under test (DUT) and the HIL simulator to identify the inputs and outputs expected from the control unit. Once the inputs and outputs were identified, a Matlab/Simulink model was designed to interface with the real-time environment of the simulator. In fact, the simulator must include a physical and mathematical model in the Simulink environment that replicates a reliable scenario so that real control units and actuators can be connected to it. Thus, starting from the Thevenin equivalent circuit of a single battery cell, a parameterizable physical model of a module with a total of twelve cells was developed using the Matlab/Simulink base library. The modelling decisions made enable testing the BMS considered with the simulated battery, regardless of the type of battery cells used, thanks to the possibility to easily change the data depending on their architecture or composition. The connection between the ECU and the Simulink model, ensured by the HIL simulator, allows, with the help of the dSpace toolchain, the study of all parameters of interest to the BMS, such as state of charge (SOC), state of health (SOH), terminal voltage, current and temperature of each cell. Hardware-In-The-Loop simulation has brought several advantages to the automotive industry, mainly because of its high repeatability, high flexibility and low cost compared to in-vehicle testing. Thanks to this simulation, the ECU can be made to pretend that it's inside the vehicle, so that the characteristics of the BMS can be deepened through real-time testing.