To reduce the energy consumption of electric vehicle heating system, a cascade heating system with multiple heat sources distributed based on waste heat recycling was designed. Firstly, the thermal load of the carriage was analyzed and calculated, providing a basis for the selection and matching of heating components. To explore the heating sequence and heat production, a heat release model for the power battery, drive motor, and controller was built, and simulation analysis using ANSYS was conducted to explore heat release laws. Considering the impact of heat released by drivers and passengers on the temperature inside the vehicle, a pyroelectric infrared technology was designed to detect the number of drivers and passengers, in order to estimate their heat release. A cascade collaborative heating method with multiple heat sources distributed was designed, and the optimal heating method could be selected in a timely manner based on the heat release law of the heat sources, environmental temperature, and the number of drivers and passengers. Finally, low-temperature tests were conducted on the heating air system, and the results showed that after operating for 2 hours at an ambient temperature of -22℃, compared with traditional electric vehicle heating, the proposed method saved 31.1% and 63.6% energy, respectively, verifying its superiority.

electric vehicles  /  heating system  /  waste heat cycle  /  cascade control