Choice of Energetically Optimal Operating Points in Thermal Management of Electric Drivetrain Components
Increasing the efficiency of electric vehicles is a development focus in the automotive industry in order to reach the range targets set by customer requirements. Thermal management can have a positive effect on the system efficiency of electric vehicles. In this contribution, a simulation model of the drivetrain and cooling system of an electric vehicle has been build up. The aim is to investigate the influence of the cooling system control and resulting component temperatures on the drivetrain efficiency. Thus, energetically optimal target temperatures for inverter and motor can be identified and implemented in the cooling system control.
This approach goes beyond the state of the art control strategy of keeping the temperatures under the component protection threshold. Related research suggests that the component efficiency of inverter and motor can be increased by reducing their operation temperature. The simulation results in this article show that choosing target temperatures for inverter and motor below the components’ safety limit can have a small, positive impact on the system efficiency of the electric vehicle.
As the model is yet to be validated, these results implicate that the optimal component target temperatures for inverter and motor regarding system efficiency are below the protective limit. As a next step, the model will be validated with comprehensive component and vehicle measurement data in order to give a quantitative statement on the possible benefits of optimized thermal management control.
KeywordsElectric vehicles Thermal management Optimal control
Funded by the Deutsche Forschungsgemeinschaft (DFG) – GRK1856.
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