CASCADE HEAT PUMP SYSTEM FOR ELECTRIC VEHICLE

A cascade heat pump system for an electric vehicle includes a low-pressure-stage compression device, a high-pressure-stage compression device, and a functional heat exchange device. The low-pressure-stage compression device includes a low-pressure-stage compressor, a low-pressure-stage evaporator, a low-pressure expansion valve, and a low-pressure-stage intercooler connected in sequence. The high-pressure-stage compression device includes a high-pressure-stage compressor, a high-pressure-stage four-way valve, an air-side heat exchanger, a water-side heat exchanger, a cabin heat exchanger, and a battery heat exchanger. The compressor outlet of the high-pressure-stage compressor communicates with one of the air-side heat exchanger or the water-side heat exchanger. The air-side heat exchanger communicates with the cabin heat exchanger and the battery heat exchanger separately. The functional heat exchange device includes a motor heat exchange assembly, a heat exchange water tank, a battery heat exchange member, and a cabin heat exchange member.