CN201584798U - Electric balance structure of lithium battery module - Google Patents

Abstract

The utility model relates to an electric balance structure of a lithium battery module, which comprises a plurality of single cells which are connected in parallel and in series with each other. Each signal cell reaches an electric balance state by a battery control unit which comprises an average voltage detecting and calculating circuit, a comparison circuit and a plurality of by-pass devices corresponding to each signal cells. The average voltage detecting and calculating circuit periodically detects a voltage of each signal cell and calculates an average voltage thereof, and then the comparison circuit calculates an error of the voltage of each signal cell and the average voltage and compares the error with a preset voltage error value, wherein if the voltage error exceeds the preset value, the by-pass device corresponding to the signal cell can be started to reduce charging and discharging for the signal cell; and if the voltage error is less than the preset value, the by-pass device corresponding to the signal cell can be switched off. The utility model effectively avoids the phenomena of overcharge, overdischarge, reversed polarity and the like and guarantees the normal operation of charging and discharging work of the battery module.

Description

A kind of electric equilibrium structure of lithium battery module

Technical field:

The utility model relates to the electric vehicle power supply, particularly the electric equilibrium structure of electric vehicle lithium battery module.

Background technology:

The power vehicle battery module is linked together by series-parallel system by several cells and forms, because the aspects such as temperature of each cell each cell in initial capacity, voltage, internal resistance and battery module are all incomplete same, in use, can cause overcharging and the overdischarge phenomenon of certain cell.Can cause other battery of Capacity Ratio of individual cell all low when serious, in discharge process, its electric weight has at first been put, because the voltage of this battery is low, lost the ability of discharge again, at this moment it just becomes an electrical appliance, all the other still have the battery of capacity will be together in series to its charging, the reverse electrode phenomena that battery occurs makes entire cell module cisco unity malfunction, and the battery life to antipole causes great influence simultaneously.In charging process, at first exhausted cell can at first be filled again, the phenomenon of overcharging will occur like this, makes the entire cell module normally not to be filled.In fact the actual capacity of emitting in battery module is that cell by the actual capacity minimum is determined that promptly this battery capacity is accused when exhausting, and other battery can't work on, and also is like this in the charging process.Therefore use in the course of work of battery module at power vehicle, the lack of uniformity of each cell is a very harmful factors, and it is very necessary that battery module is carried out equilibrium control.

The utility model content:

The purpose of this utility model is to overcome above-mentioned the deficiencies in the prior art, provides a kind of and avoids that overcharging appears in battery, the electric equilibrium structure of the lithium battery module of overdischarge and reverse electrode phenomena.

In order to realize the foregoing invention purpose, the utility model has adopted following technical scheme:

A kind of electric equilibrium structure of lithium battery module, comprise that several pass through string, the cell that parallel way links together, described each cell reaches the electric equilibrium state by a battery control unit, described battery control unit comprises an average voltage estimation circuit, one comparison circuit and a plurality of bypass apparatus corresponding with each cell, described average voltage estimation circuit periodically detects the voltage of each cell and calculates its average voltage, then, described comparison circuit calculates the error of each monomer battery voltage and average voltage, compare with the voltage error value of presetting again, if the error of voltage exceeds preset value, the bypass apparatus corresponding with this cell just can be opened, minimizing is filled this cell, discharge, if the error of voltage is less than preset value, the bypass apparatus corresponding with this cell just can disconnect, and this cell filling before also continuing, discharge work.

The utility model has been owing to adopted above technical scheme, thereby has following advantage with respect to prior art:

The utility model is by the balance of voltage state of each cell of battery control unit real time monitoring, in the charge and discharge process when the voltage of cell begins to occur discrete situation, battery control unit will enter the electric equilibrium state, thereby effectively avoided overcharging, the appearance of phenomenon such as overdischarge and antipole, guarantee normally carrying out of battery module charge and discharge work, also prevented the premature damage of battery simultaneously.

Description of drawings:

Introduce the utility model in detail below in conjunction with the drawings and specific embodiments.

Fig. 1 is an operation principle schematic diagram of the present utility model.

Embodiment:

With reference to Fig. 1, the electric equilibrium structure of the lithium battery module that provides according to the utility model comprises the cell 1 that several link together by the series and parallel mode, and each cell 1 reaches the electric equilibrium state by a battery control unit 2.Battery control unit 2 comprises an averagevoltage estimation circuit 21, the bypass apparatus 23 that onecomparison circuit 22 and a plurality of and each cell 1 are corresponding, averagevoltage estimation circuit 21 periodically detects the voltage of each cell 1 and calculates its average voltage, then,comparison circuit 22 calculates the error of each cell 1 voltage and average voltage, compare with the voltage error value of presetting again, if the error of voltage exceeds preset value, the bypass apparatus 23 corresponding with this cell 1 just can be opened, minimizing is filled this cell 1, discharge, if the error of voltage is less than preset value, the bypass apparatus 23 corresponding with this cell 1 just can disconnect, and this cell 1 filling before also continuing, discharge work.

Claims (1)

1. the electric equilibrium structure of a lithium battery module, comprise that several pass through string, the cell that parallel way links together (1), described each cell (1) reaches the electric equilibrium state by a battery control unit (2), it is characterized in that: described battery control unit (2) comprises an average voltage estimation circuit (21), one comparison circuit (22) and a plurality of bypass apparatus (23) corresponding with each cell (1), described average voltage estimation circuit (21) periodically detects the voltage of each cell (1) and calculates its average voltage, then, described comparison circuit (22) calculates the error of each cell (1) voltage and average voltage, compare with the voltage error value of presetting again, if the error of voltage exceeds preset value, the bypass apparatus (23) corresponding with this cell (1) just can be opened, minimizing is filled this cell (1), discharge, if the error of voltage is less than preset value, the bypass apparatus (23) corresponding with this cell (1) just can disconnect, and this cell (1) filling before also continuing, discharge work.

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