关键词: 纯电动汽车；电池热管理；超级电容；正温度系统加热

Abstract: Pure electric vehicle power batteries will have a sharp decline in working efficiency in low temperature environment. This paper designs a corresponding thermal management scheme for this problem. In low temperature environment, positive temperature coefficient (PTC) heating system with feedback regulation function is used to preheat the automobile power battery before the electric vehicle motor starts to work. The four-way valve connects the battery of the cooling fluid with the motor circuit to form a new circulation circuit. After the motor starts running, comparing the change of battery temperature under the synergistic action of PTC heating system and motor residual heat under low temperature, it is found that the PTC+drive system residual heat heating mode has high heating efficiency and low energy consumption. Therefore, a low temperature heat management method is proposed, which uses the heat generated by PTC heating system and motor to heat or keep warm the battery through the cooling fluid circulation system. To compensate for the shortage of single energy in pure electric vehicles, the above heat management methods are derived from the battery-supercapacitor hybrid storage system, which ensures that the battery power of electric vehicles will not be greatly discounted by the consumption of the heat management system.

Key words: Electric vehicle; Thermal management; Super capacitor; Positive temperature coefficient heating