Abstract:

It is crucial to develop a lightweight real-time online temperature prediction model for electric drive assembly （EDA） to effectively monitor its future abnormal temperature state in advance and ensure vehicle safety. Based on multi-physics coupling and data-driven fusion modeling， this paper proposes an online prediction method for the transient temperature field of EDA. Firstly， a multi-physical coupling finite element model of EDA electric-magnetic-thermal-flow multi-physics coupling is established， and the accuracy of the model is verified by bench test. Secondly， several transient temperature field datasets under normal working conditions are generated via multi-physical field coupling model for subsequent proxy model verification. Then， combined with the finite element model to obtain the simplified thermal network topology and the graph convolutional neural network， a relational spatial-temporal graph convolutional neural network prediction model driven by model and data is proposed. Finally， the effectiveness and real-time performance of the proposed temperature prediction model are verified by offline simulation and online test under different ambient temperatures and working conditions. Analysis results on the measured offline dataset show that the global prediction error and average absolute error are 4.4 and 1.25 ℃， reduced by 17.3%， 28.1%， 5.3% and 29.3%， respectively， compared with the conventional temporal graph convolutional neural network and gated recurrent unit. Meanwhile， the online prediction results of the bench are also very close to the real measured values， with the global prediction error and average absolute error of 3.99 and 0.66 ℃. In conclusion， the proposed real-time on-line temperature prediction method can accurately predict the real temperature change of EDA.

Key words: electric drive assembly, real-time online temperature prediction, multi-physical field coupling, relational graph convolutional neural network