Charging control method and system for power battery of electric automobile

Abstract

The invention discloses a charging control method and system for a power battery of an electric automobile. The method includes the steps that after the power battery enters a charging mode, the power battery is controlled to be charged through a normal-temperature charging process according to the current highest temperature and the current lowest temperature of multiple regions in the power battery; after the power battery is fully charged, heating is started when the current lowest temperature and the current highest temperature are both low, and therefore the power battery is controlled to enter a heating and heat preservation process; and when heat preservation time does not reach a heat preservation time threshold value, and the current lowest temperature is not higher than a temperature threshold value in the heating and heat preservation process, the power battery is controlled to be subjected to heat preservation continuously, the power battery retracts from the heating and heat preservation process, after the power battery stands still for preset time, a heat preservation time judgment step is executed again, and therefore the next-time discharging temperature of the power battery is guaranteed. By the adoption of the method of the embodiment, the power battery can be effectively charged at the low temperature, the discharging efficiency of the power battery in the low-temperature stand-still process of the power battery can be improved, the problem that the running mileage of the electric automobile is short is solved, and the user experience is improved.

Description

technical field [0001] The invention relates to the technical field of electric vehicle charging, in particular to a charging control method and control system for a power battery of an electric vehicle. Background technique [0002] The power battery in an electric vehicle is generally a lithium-ion battery. Under low temperature conditions, its conductivity is poor, and the diffusion speed of lithium ions is slow, making it impossible to charge and discharge or reduce the charging and discharging power, which will affect the normal charging or driving of the vehicle. . [0003] In the related art, when the lithium-ion power battery is charged under low temperature conditions, the method of preheating before charging and heating during charging is adopted to ensure that the lithium-ion power battery can be charged normally. However, it ignores that in actual use, under low temperature conditions, the power battery is fully charged and left to stand, the temperature will dr...

AI Technical Summary

Problems solved by technology

But it ignores that in actual use, under low temperature conditions, the power battery is fully charged and left to stand, the temperature will drop, making its discharge efficiency low, which in turn results in short mileage of electric vehicles

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