Lithium battery equalization control system and control method thereof

Abstract

The invention provides a lithium battery equalization control system and a control method thereof. The method comprises the following steps: an equalization power supply is arranged outside a batterypack; when the power difference between the batteries collected by a battery management system exceeds a preset value, the power supply and the battery pack are connected; the battery management system judges and finds out low-power batteries through a control circuit thereof according to the collected battery voltages; the control circuit makes gating switches and a power polarity reversal switchof an equalization circuit act, and sends a charging instruction to the power supply; and after the equalization of the low-power batteries is completed, the control circuit makes the equalization circuit switch off the corresponding gating switches and the power polarity reversal switch. Thus, the technical problem caused by the fact that the charging / discharging equipment is arranged outside inthe existing battery management system equalization mode is solved, one equalization power supply can equalize multiple battery packs, the number of components of the lithium battery equalization control system is reduced, and the cost and failure rate of the battery management system are reduced.

Description

technical field [0001] The present invention relates to the technical field of a lithium battery battery management system (BATTERY MANAGEMENT SYSTEM, abbreviated as BMS), in particular to a lithium battery balance control system and a control method based on the system. Background technique [0002] With the enhancement of people's awareness of environmental protection, electric vehicles have become popular rapidly. Current electric vehicles mainly use lithium batteries as their energy source. Among them, in the long-term use of lithium batteries, there will be differences in charge and discharge capacity among groups of lithium battery packs, and when the differences become larger and larger, it will affect the mileage of electric vehicles. [0003] In order to solve the aforementioned problems, it is generally overcome by adding an equalization function to the lithium battery management system. There are two current lithium battery equalization methods: energy transfer ...

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Problems solved by technology

[0007] In view of the above situation, the present invention provides a lithium battery balance control system and its control method, which solves the technical problems caused by external charging / discharging equipment in the balance mode of the existing battery management system by placing the balance power supply externally, and achieves a balance The power supply can meet the balance of multiple battery packs, and reduce the components of the lithium battery balance control system, reduce the cost of the lithium battery battery management system and reduce the failure rate, etc.

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