60 Chapter 6 Private companies, such as software analysis developer CD-ADAPCO who is also one of the participants in the CAEBAT program, already offer several analysis tools that are designed to help in the evaluation of different cell types, chemistries, and thermal performance but their solutions are currently targeted at the cell-level development. In addition to the private companies developing software and analysis tools, many of the government labs and universities have been deeply engaged in developing tools. One such group is the Impact and Crashworthiness Laboratory at MIT.
The MIT lab has been working to develop models in order to evaluate the effects of vehicle crash situations on the compo- nents within the cells, the cells themselves, and the battery pack overall. Their work has focused on understanding the effects of crash and penetration on each of the different types of battery cells through modeling, simulation, and then correlating that to actual testing. In a recent research paper published in The Journal of Power Sources (Zia, Wierzbicki, Sahraei, & Zhang, 2014), the MIT team presented their findings and analysis of the influence of road debris impacting battery packs mounted underneath the vehicle.
This research was done in response to several incidents involving Tesla electric vehicles wherein the vehicle ran over debris in the road which subsequently penetrated the battery and caused failure of the pack. Through the use of several different modeling and simulations, the MIT team was able to develop a set of recommendations to assist vehicle and battery designers in first understand- ing the results of these types of events and then ensuring the safety of the battery when these events occur (Xia, Wierzbicki, Sahraei, & Zhang, 2014). Another provider of software tools that is capable of this type of analysis is ANSYS.
ANSYS offers a suite of software analysis tools called “Fluent,” which is an advanced computational fluid dynamics (CFD) tool. While the tool was originally designed for analyzing mechanical and thermal systems, it does a very good job of analyzing the thermal management systems in energy storage systems. In this software package, the battery is modeled and the material properties and the heat generation of the cells are identified and associated to their respective components. The software then models the flow of either cooling (or heating) air or liquid within the battery pack in order to evaluate its effectiveness at cooling the battery as well as to analyze “hot spots” (ANSYS, 2014).
This is a very valuable tool that can be used in designing the thermal system by modeling, modifying the design, and then running the model again and repeating this process in order to develop an optimized thermal solution. Another tool that may be evaluated to use for lithium-ion battery cell and system thermal analysis is Abaqus by DS Simulia. Similar simulation and modeling software products are offered by companies such as Math- Works, which offers a suite of products called MATLAB and SIMULINK. These two tools are integrated into a product that is designed to build and simulate mathematical models, algorithm development, and many mathematical models (MathWorks, 2014).
MATLAB and SIMULINK are development tools that are frequently used by software engineers in design- ing the battery management system (BMS) software, communication and controls systems.