The replacement of internal combustion engine vehicles with electric vehicles is becoming an important developmental direction in the automotive industry because of increasingly serious environmental problems and climate change. The high energy consumption for heating from heat pump air-conditioning systems leads to a reduction in the driving range of electric vehicles in winter. In this study

a simulation model of a heat-pump air-conditioning system for electric vehicles was established and its operating performance was analyzed in various air circulation modes under different ambient conditions. The results showed that the energy consumption in the outside air circulation mode was 34.4% higher than that of the recirculated air circulation mode under typical winter conditions in the cold zone. Furthermore

the energy consumption of the outside air circulation mode was reduced by 17.1% compared with the recirculated air circulation mode under typical winter conditions in the hot summer and warm winter zone. The energy consumption of heat pump air-conditioning systems for electric vehicles can be reduced by reasonably controlling the air circulation mode based on ambient conditions on the premise of meeting the requirements of temperature and humidity in the cabin. A control strategy for the energy-saving operation of a heat pump air-conditioning system for electric vehicles in winter is proposed and presented based on the ambient air psychrometric chart through regional division. In addition

the energy-saving operation mode of the heat pump air-conditioning system for electric vehicles in winter for different climatic zones and the number of passengers varying in the cabin are discussed.