Techniques to evaluate Energy Efficiency and Performance of an Electric Vehicle by leveraging Co-simulation

After designing any Powertrain component/subsystem for a conventional or an Electric vehicle, System Energy efficiency and Performance improvement Simulations are an very important step to prove the worthiness of the product before we can go for Prototypes, Vehicle level Integration, Testing and benefit’s evaluation phases. This work describes how two simulation tools have been leveraged effectively for Energy efficiency and Performance simulations for an Electric vehicle. Schaeffler has an internal Physical modeling tool for building vehicle level models. This tool has readymade physical component blocks for various Mechanical and Electrical components. These blocks can be parameterized as per required specifications. The powertrain subsystems like the Battery, BLDC Motor, Vehicle Inertias and the Multi-speed transmission consisting of various mechanical elements have been modeled and parameterized using this tool. This tool is the front end of the Co-simulation. The Physical model is used to provide various model inputs like Drive cycles, Motor and Battery characteristics, Throttle and Gear Shift maps. On the backend we leverage the Equation and Logics modeling capabilities of Matlab Simulink. The Driver and the Vehicle model have been made using Matlab Simulink. The Driver model consists of logics which provides various outputs like Throttle,Brake and vehicle Power demand. The Vehicle models consists of algorithms which provides outputs like Desired Motor Torque and transmission gear position. These two Matlab Simulink models are converted into Standalone Functions/Codes and integrated into the Physical model. Thus, all the three models are looped to each other. The advantage of this co-simulation is that the user has to only interact with only one tool, at the same time reaping the benefit of the other tool/s in the background. This utilizes the best of both world's. Thus co-simulation is a very good technique to simulate complex subsystems by leveraging advantages of multiple Simulation tools to get faster and accurate results.