Machine Learning Models for Estimating Temperatures of Electric Powertrains

Sammanfattning

Towards a sustainable future, more and more powertrains are being electrified today, thus it is important to prevent unwanted failures and secure a reliable operation. Monitoring the internal temperatures of powertrains and keeping them under their thresholds is an important first step. Traditional modeling methods require expert knowledge and complicated modeling. With all the operating information an electric drive can collect nowadays about the whole powertrain, it becomes possible to apply black boxed machine learning to do the temperature estimating job. In this thesis, multiple machine learning algorithms are tested on their ability to estimate temperatures of the rotor fin, the stator winding, the bearing, and the power module case. The tested algorithms range from an ordinary least square to a deep neuron network. For this purpose, about 150 hours of data are recorded by letting the system run under predefined operating conditions. A hyperparameter search is also conducted for each model to find the best configuration. All the algorithms are evaluated by several metrics. It has been found that neuron networks can perform quite well even under fast transient conditions without any expert knowledge.