Hybrid thermal point mass network approximated/electrochemical cell simulation model approach for simulation aided testing on thermal management cell level of BEV, FCEV and hybrid ICE architectures

Abstract

This paper deals with the design of a thermal network for simulating the behaviour of individual cells, both autonomously and in combination. It concludes an evaluation of a suitable overall simulation methodology at the electrochemical-thermal level and is based on a series of findings and results from previous in-depth research in the field of cell electrochemistry. Another focus is on the development of a cycle environment that makes it possible to simulate real cell behaviour on the test bench. This article will address the abstraction of the individual cell layers into a volume represented by thermal masses, as well as its parametrization and structure within the simulation methodology. The greatest effort in creating and parametrizing the cell as a thermal network result from the need to make it completely variable in order to meet user requirements. At this stage of the simulation setup, the aim was to move beyond the stand-alone cell level and consider subunits in the form of module or pack arrangements. Accordingly, in addition to electrochemical simulation using the electrochemical model (ECM), thermal network simulation using the thermal network model (TNM) is also adapted. One challenge was the parametrization of the transition layer between the individual cell shells and the (cooling) environment within the module or pack arrangements. As part of the overall simulation methodology, validation was performed at the single-cell level to compare the results of the surface temperature distribution as well as the current and voltage levels occurring during operation with measurements of corresponding cells on the test bench.