Modeling and Control of Thermal Cycles in Vehicle Electrification

Thermal systems in electric and hybrid vehicles operate with a higher number of components than equivalent systems in conventional vehicles. While thermal management of the combustion engine, transmission and the passenger cabin is implemented in well-known and proven way, the integration of electric motors, power electronics and the battery introduces new challenges for thermal management in automotive industry. The battery for example needs to operate at its well defined temperature level. The electric motor on the other hand operates at different temperature level and the power electronics operates at yet another temperature level. The temperature and the humidity in the passenger cabin must assure a suitable comfort. This requires an air conditioning system, which again operates at different temperature level. Multiple levels of operational temperatures require an effective thermal management of the overall vehicle. It must also assure that components operate at high efficiency in order to provide the best trade-off between the mileage and the passenger comfort. Since thermal processes are nonlinear in nature, the thermal management is a complex process. This paper presents modeling approaches used to model thermal processes. The optimization techniques and some nonlinear control strategies for increasing energy efficiency of thermal cycles in vehicle electrification applications are highlighted.