Heating control method and system during direct-current fast charging in low temperature environment

Abstract

The invention relates to a heating control method and system during direct-current fast charging in the low temperature environment. The method is characterized by comprising the steps S1, after charging handshaking is carried out with a direct-current charging pipe, a major loop and a charging loop relay are closed, and after a heating request of a whole vehicle controller is received, S2 is executed; S2, a charging mode is set as a constant voltage mode, and after setting is completed, the whole vehicle controller is requested to start a heater; S3, it is judged whether or not the heater isstarted to work and a high-pressure de-energizing request of the whole vehicle controller is received, if yes, S4 is executed, and if not, if the time T is exceeded, S5 is executed; S4, a main positive relay and main negative relay of a battery pack are disconnected, constant voltage power supply is carried out on the heater, and when the minimum temperature point of the battery pack reaches a settemperature, the whole vehicle controller is requested to stop heating, and S5 is executed; S5, a charging mode is set as a constant current mode, and normal charging is carried out in the constant current mode. Compared with the prior art, the heating control method and system can avoid the situation that the current flows into a power battery during heating.

Description

technical field [0001] The invention relates to low-temperature charging auxiliary technology for power batteries of electric vehicles, in particular to a heating control method and system during DC fast charging in a low-temperature environment. Background technique [0002] With the continuous development and popularization of new energy vehicles, users' requirements for vehicle performance are also increasing. In the northern regions, especially in places where the winter is particularly cold, it is often necessary to charge the battery in a low temperature environment, but charging the battery in a low temperature environment will cause irreversible damage to the battery, and it is very necessary to heat the battery pack at this time. [0003] At present, there are two main low-temperature heating methods for vehicles on the market, heating with battery pack power and heating with on-board chargers. [0004] Use the power of the battery pack for heating. When the temper...

AI Technical Summary

Problems solved by technology

[0006] The above-mentioned scheme of using the power of the battery pack for heating can only be controlled when the power of the battery pack is high. When the power of the battery pack is low or there is no power, not only cannot be heated, but even cannot be charged due to the inability to heat.

[0007] The use of on-board chargers for heating is currently the most common heating method, but at the same time, on-board heating will further prolong the continuous high-load operation time of on-board chargers. With the aging of chargers, the probability of potential safety hazards also increases. will gradually increase

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