Active equalizing charging method and device for LiFePO4 power battery packs

Abstract

The invention provides an active equalizing charging method for LiFePO4 power battery packs. The method comprises the following steps: detecting the parameters of single batteries in real time, calculating the charge states of the single batteries according to the detected parameters, and calculating and updating the average charge state of a battery pack in real time according to the obtained charge states of the single batteries; comparing the charge state of each single battery with the average charge state of the battery pack; when the charge state of a single battery is less than the average charge state of the battery pack, carrying out equalizing charging on the single battery; when the charge state of a single battery is close to a threshold of the average charge state of the battery pack, ending the equalizing charging of the single battery; when the charging of all the single batteries subjected to equalizing charging is completed, determining that the equalizing charging of the whole battery pack is completed, at this moment, the charge states of all the batteries are basically consistent; repeating the steps so as to carry out a new cycle; and when the charge states of all the single batteries in the battery pack are all close to the average charge state of the battery pack, stopping equalizing charging.

Description

technical field [0001] The invention relates to the technical field of power battery charging, in particular to an active balanced charging method and a balanced charging device for a lithium iron phosphate power battery pack. Background technique [0002] In recent years, the urban air pollution problem caused by vehicle exhaust emissions has been highly valued by the governments of various countries, and the promotion and use of electric vehicles is considered to be the best way to finally solve this problem. Electric vehicles have the characteristics of high energy utilization rate and the comprehensive utilization of various energy sources, which is of great significance to global energy conservation and the upgrading of energy forms. [0003] The power battery is an essential and important part of the electric vehicle, and the power supply quality of the power battery is directly related to the normal and reliable operation of the electric vehicle. Since the voltage an...

AI Technical Summary

Problems solved by technology

The energy consumption of this circuit is smaller than that of the energy dissipation type, and it is widely used in the equalization charging of small-capacity lithium-ion batteries, but there are still many problems in the equalization charging of large-capacity lithium-ion batteries: (1) The circuit structure is relatively complex ; (2) cannot achieve very precise equalization; (3) the equalization time is very long

[0009] The Chinese Patent No. 201010213210 discloses that "power battery pack equalization control method adopts resistance discharge equalization", which is an energy loss type equalization, which is not applicable to large-capacity batteries, and equalization consumes a lot of energy. Only suitable for small capacity batteries

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