A system and method for modular active equalization of series battery packs

Abstract

A management apparatus for series battery includes a conversion unit electrically connected to a plurality of series cell, wherein that conversion unit includes a switch assembly configured to controla closed state of a plurality of loops correspond to the plurality of single cells; And a charging, discharging and voltage transformation assembly configured to operate in a charge, discharge or transformer mode to achieve power dispatch between adjacent and non-adjacent cell units; The battery management apparatus further includes a control unit electrically connected to the conversion unit, configured to detect a state of the battery, and control a state of the switch assembly and an operation mode of the charge-discharge and transformer assembly. Inside each battery cell, the power exchange between the batteries is realized by controlling the power switch tube and the transformer, and the power exchange between adjacent battery cells is realized by sharing a single battery. The time of the power exchange is short, and the energy transfer loss is small.

Description

technical field [0001] The invention relates to the technical field of battery management, in particular to a modularized active equalization system and method for series battery packs. Background technique [0002] When using multiple single cells in series to form a battery pack, due to the inconsistency of the capacity of the single cells and the difference in the ambient temperature of the single cells in use, this inconsistency will be exacerbated, which will cause the battery pack to discharge when the battery pack is discharged. , when the single battery with the smallest capacity is exhausted, it cannot be used even if other batteries still have power; while charging the battery pack, the battery with the smallest power is fully charged first, even if other batteries have spare capacity, they cannot be charged again , resulting in a decrease in the overall capacity utilization of the battery pack, so it is necessary to use a battery management system to manage all th...

AI Technical Summary

Problems solved by technology

In this way, if there are K single batteries between the two single batteries that need to be balanced, the power balance between them needs to be completed through K+1 power transfers, and the entire transfer process not only needs to consume more energy, and requires a long delivery time

[0007] Aiming at the above-mentioned technical problems in using switching power supply to realize active equalization management, some researchers have proposed a technical solution of using multi-winding transformers to realize single battery energy transfer. A series battery pack equalization circuit with a symmetrical multi-winding transformer structure and a control method applied to the circuit. However, when the number of windings of this single-core multi-winding technical solution increases, the manufacturing and mechanical reliability of the transformer become very difficult. ; At the same time, the maintenance and replacement of transformers are also very expensive

[0008] At the same time, the existing BMS generally adopts the CAN bus transmission method, which not only makes the system wiring complicated, but also when it is applied to electric vehicles, the environmental factors in the driving process of the vehicle will affect the stability of the CAN bus transmission, greatly reducing the overall BMS. stability and reliability

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