Battery-electric rail vehicles are a sustainable alternative for diesel-powered vehicles on tracks without catenary. However, the energy demand to heat and cool the cabin limits the vehicle range, and the applied synthetic refrigerants are environmentally harmful. Therefore, this paper studies how energy demand and load on the battery in battery-electric rail vehicles can be reduced using heat pumps with natural refrigerants and efficient thermal management. A heat pump and thermal car body model are developed and validated, which calculate the energy demand in battery-electric rail vehicles. In these models, an optimized thermal management strategy is implemented, which changes the cabin set-point temperature based on catenary availability. For a two-car battery-electric rail vehicle in the climate zone II of Central Europe, the annual thermal energy demand is up to 110 MWh. The application of a heat pump with R290 (propane) can reduce the annual electrical energy demand for heating and cooling by up to 55%. The load on the battery can be mitigated further with the optimized thermal management strategy, reducing the equivalent full cycles by 3%. Overall, the heat pump operation and efficient thermal management strategy lead to higher vehicle range and flexibility in daily operation, increasing the acceptance of battery-electric rail vehicles.

Battery-electric rail vehicles are a sustainable alternative for diesel-powered rail vehicles operating on tracks without catenary. Heating, ventilation and air conditioning units for those vehicles use typically synthetic refrigerants, which are harmful to the environment. Additionally, the energy demand to heat and cool the cabin is limiting vehicle range and flexibility in operation. Therefore, the presented paper studies how energy demand and load at the traction battery in battery-electric rail vehicles can be reduced using heat pumps with natural refrigerants and an efficient thermal management strategy.A heat pump and thermal car body model are developed and validated, which calculate the electrical energy demand for heating, ventilation and air conditioning in battery-electric rail vehicles. In those models, an optimized thermal management strategy is implemented which changes the cabin setpoint temperature based on catenary availability.For a 2-car battery-electric rail vehicle in climate zone II the annual thermal energy demand is up to 110 MWh. The application of a heat pump with propane as refrigerant can reduce the annual electrical energy demand for heating and cooling by up to 55 % based on the modeled COP curves. The load at the battery can be mitigated further with the optimized thermal management strategy, reducing the equivalent full cycles by 3 %.Overall, the heat pump operation and efficient thermal management strategy lead to a higher vehicle range and flexibility in daily operation, increasing the user acceptance of battery-electric rail vehicles at rail operators and leading to more sustainable public rail transport.