CN104600760A - Single battery balancing control method and system for battery packs - Google Patents
Single battery balancing control method and system for battery packs Download PDFInfo
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- CN104600760A CN104600760A CN201310526210.XA CN201310526210A CN104600760A CN 104600760 A CN104600760 A CN 104600760A CN 201310526210 A CN201310526210 A CN 201310526210A CN 104600760 A CN104600760 A CN 104600760A
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- 238000000034 method Methods 0.000 title claims abstract description 62
- 230000008569 process Effects 0.000 claims description 26
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 12
- 229910052744 lithium Inorganic materials 0.000 description 12
- 238000005516 engineering process Methods 0.000 description 4
- 238000013507 mapping Methods 0.000 description 4
- 230000002159 abnormal effect Effects 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000012512 characterization method Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
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Classifications
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/0013—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries acting upon several batteries simultaneously or sequentially
- H02J7/0014—Circuits for equalisation of charge between batteries
- H02J7/0016—Circuits for equalisation of charge between batteries using shunting, discharge or bypass circuits
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- H02J7/0086—
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- H02J7/0091—
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- Charge And Discharge Circuits For Batteries Or The Like (AREA)
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Abstract
The invention provides a single battery balancing control method for battery packs. The method comprises the following steps: the terminal voltages of a plurality of single batteries in a battery pack are acquired; the average terminal voltage of the battery pack is worked out according to the terminal voltages of the plurality of single batteries; a first balance opening threshold corresponding to a preset voltage interval to which the average terminal voltage belongs is acquired from a plurality of consecutive preset voltage intervals; whether the battery pack has a single battery needing power balancing is judged according to the terminal voltages and the average terminal voltage of the battery pack; and if the battery pack has a single battery needing power balancing, power balancing is performed on the single battery needing power balancing according to the first balance opening threshold. According to the single battery balancing control method for battery packs of the invention, different balance opening thresholds for power balancing are selected for different average terminal voltages of battery packs, the interference brought by the nonlinear relationship between the charge state and the terminal voltage of a single battery is effectively avoided, and a correct power balancing decision can be made. The invention further provides a single battery balancing control system for battery packs.
Description
Technical field
The present invention relates to power battery technology field, particularly a kind of cell balance control method of battery pack and system.
Background technology
In the power battery pack be composed in series by multiple cell, cell there are differences in the fabrication process unavoidably, simultaneously in the use procedure of battery pack, the heat radiation of each cell and discharge and recharge etc. also there are differences, the terminal voltage which results between each cell is different, i.e. so-called cell energy imbalance.If do not carry out electric quantity balancing in time to unbalance battery pack, the terminal voltage difference between cell can be caused increasing, thus cause the deterioration of battery performance and the reduction in useful life, therefore the electric quantity balancing of cell be seemed particularly important.
In the electric quantity balancing technology of current cell, usually select the SOC(State of Charge of cell, state-of-charge) or terminal voltage as the foundation of electric quantity balancing.There is Nonlinear Mapping relation curve as shown in Figure 1 in the state-of-charge of the cell of lithium battery and terminal voltage.
When the differing greatly of other cell in the state-of-charge of certain cell or terminal voltage and battery pack, namely there is energy imbalance, electric quantity balancing must be carried out to this cell, it comprises two kinds of situations, when the state-of-charge of certain cell or terminal voltage are apparently higher than other cell, now need to discharge to reach new electric quantity balancing to this cell; When the state-of-charge of certain cell or terminal voltage are starkly lower than other cell, now need to charge to reach new electric quantity balancing to this cell.
The state-of-charge of cell directly reflect cell current residual electricity number, be the first-selected key element as electric quantity of single batteries balance foundation.But, very complicated to the estimation of cell state-of-charge, and present stage state-of-charge estimation error generally more than 5%.When state-of-charge estimation precision is not high enough, if still select cell state-of-charge as the foundation of electric quantity balancing, the electric quantity balancing made mistake will be made and determine, thus run counter to desire, cause the difference between cell increasing.
Therefore, practical application is more the foundation selecting the terminal voltage of cell to balance as electric quantity of single batteries.Take terminal voltage as the electric quantity balancing control general employing the following two kinds mode of foundation: when the terminal voltage difference 1) when between any two cells exceedes setting threshold; 2) when the terminal voltage of any one cell and the difference of average terminal voltage exceed setting threshold.
Above-mentioned electric quantity balancing mode does not consider the non-linear relation between cell state-of-charge and terminal voltage.The state-of-charge of lithium battery as shown in Figure 1 and the Nonlinear Mapping relation curve of terminal voltage known, when cell state-of-charge is higher or lower, the slope of curve is comparatively large, and when cell state-of-charge is near 50%, the slope of curve obviously diminishes.Therefore, fixed threshold can be utilized select the cell needing electric quantity balancing, such as, open electric quantity balancing when difference is 0.1V, but there are the following problems in meeting: when battery pack average terminal voltage is higher, as 4.1V, if when the difference of a certain cell and average terminal voltage is 0.1V, because now the slope of curve is large, namely the state-of-charge of this cell and the state-of-charge difference of battery pack and little, without the need to opening electric quantity balancing; When battery pack average voltage is near 3.7V, if when the terminal voltage of a certain cell and the difference of average terminal voltage are 0.1V, because now the slope of curve is less, also namely the state-of-charge of this cell and the state-of-charge of battery pack differ greatly, and need to open electric quantity balancing.As can be seen here, opening electric quantity balancing has some limitations to select fixed threshold to determine whether.
Summary of the invention
The present invention is intended at least one of solve the problems of the technologies described above.
For this reason, first object of the present invention is the cell balance control method proposing a kind of battery pack, the method can select different electric quantity balancings balance for different battery pack average terminal voltage opens threshold value, effectively avoid the interference that the non-linear relation due to cell state-of-charge and terminal voltage is brought, make correct electric quantity balancing and determine.
Second object of the present invention is the cell balance control system proposing a kind of battery pack.
To achieve these goals, the embodiment of the present invention first aspect proposes a kind of cell balance control method of battery pack, described battery pack comprises multiple cells of series connection, said method comprising the steps of: the terminal voltage gathering multiple cell in described battery pack; The average terminal voltage of described battery pack is obtained according to the terminal voltage of multiple described cell; Interval the first corresponding balance of predeterminated voltage obtaining described average terminal voltage place from multiple continuous print predeterminated voltage interval opens threshold value, wherein, the balance that the predeterminated voltage interval of the both sides in described multiple continuous print predeterminated voltage interval is corresponding opens the predeterminated voltage interval corresponding balance unlatching threshold value that threshold value is greater than the centre in described multiple continuous print predeterminated voltage interval; Judge whether to exist according to the terminal voltage of described multiple cell and the average terminal voltage of described battery pack the cell needing to carry out electric quantity balancing; If existed, then open threshold value according to described first balance and electric quantity balancing is carried out to the described cell carrying out electric quantity balancing that needs.
According to the cell balance control method of battery pack of the present invention, choose the foundation of cell terminal voltage as electric quantity balancing, judge whether to exist the cell needing to carry out electric quantity balancing by terminal voltage and average terminal voltage, the balance selecting different electric quantity balancings for different battery pack average terminal voltage opens threshold value, effectively avoid the interference that the non-linear relation due to cell state-of-charge and terminal voltage is brought, make correct electric quantity balancing and determine.
In some instances, the interval corresponding balance of each predeterminated voltage is opened threshold value and from described multiple continuous print predeterminated voltage interval, is positioned at the interval corresponding balance of the second middle predeterminated voltage opens threshold value and open threshold value to the interval corresponding balance of predeterminated voltage being positioned at the interval both sides of described second predeterminated voltage and become large gradually.
In some instances, describedly judge whether to exist according to the terminal voltage of described multiple cell and the average terminal voltage of described battery pack the cell needing to carry out electric quantity balancing, specifically comprise: the first cell obtaining the maximum absolute value of the difference of terminal voltage and described average terminal voltage from described multiple cell; The absolute value of more described maximum difference and described first balances opens threshold value; If the absolute value of described maximum difference is greater than described first balance open threshold value, then judges to need to carry out electric quantity balancing to described first cell, otherwise judge there is not the cell needing to carry out electric quantity balancing.
In some instances, carrying out in the process of electric quantity balancing according to described first balance unlatching threshold value to the described cell carrying out electric quantity balancing that needs, also comprise and stop carrying out electric quantity balancing to the described cell carrying out electric quantity balancing that needs when meeting the following conditions: there is terminal voltage in the terminal voltage of described multiple cell and be greater than the terminal voltage that first threshold or terminal voltage be less than Second Threshold, described first threshold is greater than described Second Threshold; Or the temperature of described battery pack is higher than the first preset temperature or lower than the second preset temperature, and described first preset temperature is greater than described second preset temperature; Or, described in carry out charge/discharge current in the process of electric quantity balancing higher than predetermined current.
For example realizes above-mentioned purpose, the embodiment of the present invention second aspect proposes a kind of cell balance control system of battery pack, described battery pack comprises multiple cells of series connection, and described system comprises: acquisition module, for gathering the terminal voltage of multiple cell in described battery pack; Computing module, for obtaining the average terminal voltage of described battery pack according to the terminal voltage of multiple described cell; Acquisition module, interval the first corresponding balance of predeterminated voltage for obtaining described average terminal voltage place from multiple continuous print predeterminated voltage interval opens threshold value, wherein, the balance that the predeterminated voltage interval of the both sides in described multiple continuous print predeterminated voltage interval is corresponding opens the predeterminated voltage interval corresponding balance unlatching threshold value that threshold value is greater than the centre in described multiple continuous print predeterminated voltage interval; Judge module, for judging whether to exist according to the terminal voltage of described multiple cell and the average terminal voltage of described battery pack the cell needing to carry out electric quantity balancing; And balance module, when needing for judging to exist at described judge module the cell carrying out electric quantity balancing, opening threshold value according to described first balance and electric quantity balancing is carried out to the described cell carrying out electric quantity balancing that needs.
According to the cell balance control system of battery pack of the present invention, choose the foundation of cell terminal voltage as electric quantity balancing, judge whether to exist the cell needing to carry out electric quantity balancing by terminal voltage and average terminal voltage, the balance selecting different electric quantity balancings for different battery pack average terminal voltage opens threshold value, effectively avoid the interference that the non-linear relation due to cell state-of-charge and terminal voltage is brought, make correct electric quantity balancing and determine.
In some instances, the interval corresponding balance of each predeterminated voltage is opened threshold value and from described multiple continuous print predeterminated voltage interval, is positioned at the interval corresponding balance of the second middle predeterminated voltage opens threshold value and open threshold value to the interval corresponding balance of predeterminated voltage being positioned at the interval both sides of described second predeterminated voltage and become large gradually.
In some instances, described judge module is used for the first cell obtaining the maximum absolute value of the difference of terminal voltage and described average terminal voltage from described multiple cell, and the absolute value of more described difference and described first balances and opens threshold value, and when the absolute value of described difference is greater than described first balance unlatching threshold value, judge to need to carry out electric quantity balancing to described first cell, otherwise judge there is not the cell needing to carry out electric quantity balancing.
In some instances, described balance module is also for carrying out in the process of electric quantity balancing according to described first balance unlatching threshold value to the described cell carrying out electric quantity balancing that needs, when judging that stopping carries out electric quantity balancing to the described cell carrying out electric quantity balancing that needs when meeting the following conditions: there is terminal voltage in the terminal voltage of described multiple cell and be greater than the terminal voltage that first threshold or terminal voltage be less than Second Threshold, described first threshold is greater than described Second Threshold; Or the temperature of described battery pack is higher than the first preset temperature or lower than the second preset temperature, and described first preset temperature is greater than described second preset temperature; Or, described in carry out charge/discharge current in the process of electric quantity balancing higher than the first predetermined current.
Additional aspect of the present invention and advantage will part provide in the following description, and part will become obvious from the following description, or be recognized by practice of the present invention.
Accompanying drawing explanation
Above-mentioned and/or additional aspect of the present invention and advantage will become obvious and easy understand from accompanying drawing below combining to the description of embodiment, wherein:
Fig. 1 is the state-of-charge of the cell of lithium battery and the Nonlinear Mapping graph of relation of terminal voltage;
Fig. 2 is the flow chart of the cell balance control method of battery pack according to an embodiment of the invention;
Fig. 3 is the flow chart of the cell balance control method of battery pack in accordance with another embodiment of the present invention; And
Fig. 4 is the structure chart of the cell balance control system of battery pack according to an embodiment of the invention.
Embodiment
Be described below in detail embodiments of the invention, the example of described embodiment is shown in the drawings, and wherein same or similar label represents same or similar element or has element that is identical or similar functions from start to finish.Being exemplary below by the embodiment be described with reference to the drawings, only for explaining the present invention, and can not limitation of the present invention being interpreted as.
In describing the invention, it will be appreciated that, term " " center ", " longitudinal direction ", " transverse direction ", " on ", D score, " front ", " afterwards ", " left side ", " right side ", " vertically ", " level ", " top ", " end ", " interior ", orientation or the position relationship of the instruction such as " outward " are based on orientation shown in the drawings or position relationship, only the present invention for convenience of description and simplified characterization, instead of indicate or imply that the device of indication or element must have specific orientation, with specific azimuth configuration and operation, therefore limitation of the present invention can not be interpreted as.In addition, term " first ", " second " only for describing object, and can not be interpreted as instruction or hint relative importance.
In describing the invention, it should be noted that, unless otherwise clearly defined and limited, term " installation ", " being connected ", " connection " should be interpreted broadly, and such as, can be fixedly connected with, also can be removably connect, or connect integratedly; Can be mechanical connection, also can be electrical connection; Can be directly be connected, also indirectly can be connected by intermediary, can be the connection of two element internals.For the ordinary skill in the art, concrete condition above-mentioned term concrete meaning in the present invention can be understood.
Describe cell balance control method and the system of battery pack according to an embodiment of the invention below in conjunction with accompanying drawing, determine whether opening electric quantity balancing by the method taking balance unlatching threshold value to change with the difference of battery pack average terminal voltage.
Fig. 1 is the state-of-charge of the cell of lithium battery and the Nonlinear Mapping graph of relation of terminal voltage, when battery pack average terminal voltage is higher or lower, as shown in Figure 1, because the slope of curve is larger, therefore select larger balance turn-on threshold voltage, average terminal voltage is more close to two ends limiting value, and the slope of curve is larger, and the balance turn-on threshold voltage therefore selected is higher.And when battery pack average terminal voltage mediates, because now the slope of curve is less, slight terminal voltage difference may cause the difference of large state-of-charge, the therefore balance turn-on threshold voltage of selection of small.
Fig. 2 is the flow chart of the cell balance control method of battery pack according to an embodiment of the invention, as shown in Figure 2, the flow chart of the cell balance control method of battery pack according to an embodiment of the invention, wherein, battery pack comprises multiple cells of series connection, and the method comprises the following steps:
Step S101: the terminal voltage gathering multiple cell in battery pack.In one embodiment of the invention, take nominal voltage as the lithium battery of 3.7V be example, describe the cell balance control method of the battery pack of the embodiment of the present invention in detail.
Step S102: the average terminal voltage obtaining battery pack according to the terminal voltage of multiple cell.
Step S103: interval the first corresponding balance of predeterminated voltage obtaining average terminal voltage place from multiple continuous print predeterminated voltage interval opens threshold value, wherein, the balance that the predeterminated voltage interval of the both sides in multiple continuous print predeterminated voltage interval is corresponding opens the predeterminated voltage interval corresponding balance unlatching threshold value that threshold value is greater than the centre in multiple continuous print predeterminated voltage interval.When the average terminal voltage of battery pack is in different phase respectively, opens threshold value by balance table 1 Suo Shi and determine the need of carrying out electric quantity balancing.
Table 1 lithium battery average terminal voltage and balance open that threshold value is corresponding to be shown
As shown in table 1, in an embodiment of the present invention, the interval corresponding balance of each predeterminated voltage is opened threshold value and from multiple continuous print predeterminated voltage interval, is positioned at the interval corresponding balance of the second middle predeterminated voltage opens threshold value and open threshold value to the interval corresponding balance of predeterminated voltage being positioned at the interval both sides of the second predeterminated voltage and become large gradually.
Step S104: judge whether to exist the cell needing to carry out electric quantity balancing according to the terminal voltage of multiple cell and the average terminal voltage of battery pack, specifically comprise:
The first cell of the maximum absolute value of the difference of terminal voltage and average terminal voltage is obtained from multiple cell.
The absolute value of more maximum difference and first balances opens threshold value.
If the absolute value of maximum difference is greater than the first balance open threshold value, then judges to need to carry out electric quantity balancing to the first cell, otherwise judge there is not the cell needing to carry out electric quantity balancing.
Step S105: if existed, then open threshold value according to the first balance and carry out electric quantity balancing to needing the cell carrying out electric quantity balancing.
Concrete, after the nominal voltage lithium battery group that is 3.7V is started working, first gather the terminal voltage of each cell and calculate the average terminal voltage of battery pack, average terminal voltage as calculated is 3.1V, now 1 known by tabling look-up, average terminal voltage is the first balance unlatching threshold value of the battery pack of 3.1V is 0.2V, now calculate the absolute value of the terminal voltage of each cell and the difference of average voltage 3.1V, if the absolute value that there is the difference of a certain cell and average terminal voltage is greater than 0.2V, then need to carry out electric quantity balancing to cell, if the absolute value that there is the difference of the terminal voltage of multiple cell is all greater than 0.2V, that cell then choosing the maximum absolute value of difference carries out electric quantity balancing, if there is no the cell that the absolute value of difference is greater than 0.2V does not then carry out electric quantity balancing.
Here it should be noted that, carrying out in the process of electric quantity balancing according to the first balance unlatching threshold value to needing the cell carrying out electric quantity balancing, also comprising and stopping needing the cell carrying out electric quantity balancing to carry out electric quantity balancing when meeting the following conditions:
There is terminal voltage in the terminal voltage of multiple cell and be greater than the terminal voltage that first threshold or terminal voltage be less than Second Threshold, first threshold is greater than Second Threshold, such as when the terminal voltage of some cells is greater than 4.2V or is less than 2.8V, stop needing the cell carrying out electric quantity balancing to carry out electric quantity balancing.
The temperature of battery pack is higher than the first preset temperature or lower than the second preset temperature, first preset temperature is greater than the second preset temperature, such as when the working temperature of battery pack is higher than 50 DEG C or lower than 0 DEG C, stop needing the cell carrying out electric quantity balancing to carry out electric quantity balancing.
Carry out charge/discharge current in the process of electric quantity balancing higher than predetermined current, such as, when the charge/discharge current of battery pack is higher than 6C.
After battery pack receives shutoff instruction, electric quantity balancing terminates, otherwise battery pack can also get back to the cell that initial condition continues to select to need electric quantity balancing.
According to the cell balance control method of battery pack of the present invention, choose the foundation of cell terminal voltage as electric quantity balancing, judge whether to exist the cell needing to carry out electric quantity balancing by terminal voltage and average terminal voltage, the balance selecting different electric quantity balancings for different battery pack average terminal voltage opens threshold value, effectively avoid the interference that the non-linear relation due to cell state-of-charge and terminal voltage is brought, make correct electric quantity balancing and determine.
Fig. 3 is the flow chart of the cell balance control method of battery pack in accordance with another embodiment of the present invention, as shown in Figure 3, the flow chart of the cell balance control method of battery pack in accordance with another embodiment of the present invention, the method comprises the following steps:
Step S301: start cell balance control method, gathers the terminal voltage of multiple cell in battery pack.In one embodiment of the invention, take nominal voltage as the lithium battery of 3.7V be example, describe the cell balance control method of the battery pack of the embodiment of the present invention in detail.
Step S302: judge whether cell is in normal condition, when have the terminal voltage of cell too high or too low time, be then in abnormal state of affairs, perform step S304, otherwise perform step S303.
Step S303: do not carry out cell balance control method.
Step S304: the average terminal voltage obtaining battery pack according to the terminal voltage of multiple cell, interval the first corresponding balance of predeterminated voltage obtaining average terminal voltage place from multiple continuous print predeterminated voltage interval opens threshold value, wherein, the balance unlatching threshold value of the predeterminated voltage interval correspondence of the both sides in multiple continuous print predeterminated voltage interval is greater than the predeterminated voltage interval corresponding balance unlatching threshold value of the centre in multiple continuous print predeterminated voltage interval, when the average terminal voltage of battery pack is in different phase respectively, open threshold value by balance table 1 Suo Shi to determine the need of carrying out electric quantity balancing.When the average terminal voltage of battery pack is in different phase respectively, opens threshold value by balance table 1 Suo Shi and determine the need of carrying out electric quantity balancing.
Step S305: the first cell obtaining the maximum absolute value of the difference of terminal voltage and average terminal voltage from multiple cell.
Step S306: the absolute value of more maximum difference and first balances opens threshold value.If the absolute value of maximum difference is greater than the first balance open threshold value, then judges to need to carry out electric quantity balancing to the first cell, perform step S307, otherwise judge there is not the cell needing to carry out electric quantity balancing, perform step S308.
Step S307: open threshold value according to the first balance and carry out electric quantity balancing to needing the cell carrying out electric quantity balancing.
Concrete, after the nominal voltage lithium battery group that is 3.7V is started working, first gather the terminal voltage of each cell and calculate the average terminal voltage of battery pack, average terminal voltage as calculated is 3.1V, now 1 known by tabling look-up, average terminal voltage is the first balance unlatching threshold value of the battery pack of 3.1V is 0.2V, now calculate the absolute value of the terminal voltage of each cell and the difference of average voltage 3.1V, if the absolute value that there is the difference of a certain cell and average terminal voltage is greater than 0.2V, then need to carry out electric quantity balancing to cell, if the absolute value that there is the difference of the terminal voltage of multiple cell is all greater than 0.2V, that cell then choosing the maximum absolute value of difference carries out electric quantity balancing, if there is no the cell that the absolute value of difference is greater than 0.2V does not then carry out electric quantity balancing.
Here it should be noted that, as can be seen from Table 1, the interval corresponding balance of each predeterminated voltage is opened threshold value and from multiple continuous print predeterminated voltage interval, is positioned at the interval corresponding balance of the second middle predeterminated voltage opens threshold value and open threshold value to the interval corresponding balance of predeterminated voltage being positioned at the interval both sides of the second predeterminated voltage and become large gradually.
Step S308: stop needing the cell carrying out electric quantity balancing to carry out electric quantity balancing.After battery pack receives shutoff instruction, electric quantity balancing terminates, otherwise battery pack gets back to the cell that initial condition continues to select to need electric quantity balancing.
Carrying out in the process of electric quantity balancing according to the first balance unlatching threshold value to needing the cell carrying out electric quantity balancing, stopping needing the cell carrying out electric quantity balancing to carry out electric quantity balancing when meeting the following conditions:
There is terminal voltage in the terminal voltage of multiple cell and be greater than the terminal voltage that first threshold or terminal voltage be less than Second Threshold, first threshold is greater than Second Threshold, such as when the terminal voltage of some cells is greater than 4.2V or is less than 2.8V, stop needing the cell carrying out electric quantity balancing to carry out electric quantity balancing.
The temperature of battery pack is higher than the first preset temperature or lower than the second preset temperature, first preset temperature is greater than the second preset temperature, such as when the working temperature of battery pack is higher than 50 DEG C or lower than 0 DEG C, stop needing the cell carrying out electric quantity balancing to carry out electric quantity balancing.
Carry out charge/discharge current in the process of electric quantity balancing higher than predetermined current, such as, when the charge/discharge current of battery pack is higher than 6C.
According to the cell balance control method of battery pack of the present invention, choose the foundation of cell terminal voltage as electric quantity balancing, judge whether to exist the cell needing to carry out electric quantity balancing by terminal voltage and average terminal voltage, the balance selecting different electric quantity balancings for different battery pack average terminal voltage opens threshold value, effectively avoid the interference that the non-linear relation due to cell state-of-charge and terminal voltage is brought, make correct electric quantity balancing to determine, the first cell choosing the maximum absolute value of the terminal voltage of cell and the difference of average terminal voltage in the process of electric quantity balancing balances, make the process of electric quantity balancing more targeted, can stop needing the cell carrying out electric quantity balancing to carry out electric quantity balancing in the process of electric quantity balancing, ensure the safety of the process of electric quantity balancing.
Fig. 4 is the structure chart of the cell balance control system of battery pack according to an embodiment of the invention, as shown in Figure 4, battery pack comprises multiple cells of series connection, and system comprises: acquisition module 100, computing module 200, acquisition module 300, judge module 400 and balance module 500.
Acquisition module 100 is for gathering the terminal voltage of multiple cell in battery pack.Computing module 200 is for obtaining the average terminal voltage of battery pack according to the terminal voltage of multiple cell.Acquisition module 300 opens threshold value for interval the first corresponding balance of predeterminated voltage obtaining average terminal voltage place from multiple continuous print predeterminated voltage interval, wherein, the balance that the predeterminated voltage interval of the both sides in multiple continuous print predeterminated voltage interval is corresponding opens the predeterminated voltage interval corresponding balance unlatching threshold value that threshold value is greater than the centre in multiple continuous print predeterminated voltage interval.Judge module 400 is for judging whether to exist the cell needing to carry out electric quantity balancing according to the terminal voltage of multiple cell and the average terminal voltage of battery pack.When balance module 500 needing for judging to exist at judge module 400 cell carrying out electric quantity balancing, opening threshold value according to the first balance and carrying out electric quantity balancing to needing the cell carrying out electric quantity balancing.
According to the cell balance control system of battery pack of the present invention, choose the foundation of cell terminal voltage as electric quantity balancing, judge whether to exist the cell needing to carry out electric quantity balancing by terminal voltage and average terminal voltage, the balance selecting different electric quantity balancings for different battery pack average terminal voltage opens threshold value, effectively avoid the interference that the non-linear relation due to cell state-of-charge and terminal voltage is brought, make correct electric quantity balancing and determine.
In some embodiments of the invention, judge module 400 also for obtaining the first cell of the maximum absolute value of the difference of terminal voltage and average terminal voltage from multiple cell, and the absolute value and first comparing difference balances and opens threshold value, and when the absolute value of difference is greater than the first balance unlatching threshold value, judge to need to carry out electric quantity balancing to the first cell, otherwise judge there is not the cell needing to carry out electric quantity balancing.
In one embodiment of the invention, take nominal voltage as the lithium battery of 3.7V be example, describe the cell balance control system of the battery pack of the embodiment of the present invention in detail.First acquisition module 100 gathers the terminal voltage of each cell, computing module 200 calculates the average terminal voltage of battery pack, average terminal voltage as calculated is 3.1V, acquisition module 300 is 1 known by tabling look-up, average terminal voltage is the first balance unlatching threshold value of the battery pack of 3.1V is 0.2V, judge module 400 now calculates the absolute value of the terminal voltage of each cell and the difference of average voltage 3.1V, if the absolute value that there is the difference of a certain cell and average terminal voltage is greater than 0.2V, then balance module 500 needs to carry out electric quantity balancing to cell, if the absolute value that there is the difference of the terminal voltage of multiple cell is all greater than 0.2V, that cell that then balance module 500 chooses the maximum absolute value of difference carries out electric quantity balancing, if there is no the absolute value of difference be greater than 0.2V cell then balance module 500 do not carry out electric quantity balancing.
Here it should be noted that, as shown in table 1, the interval corresponding balance of each predeterminated voltage is opened threshold value and from multiple continuous print predeterminated voltage interval, is positioned at the interval corresponding balance of the second middle predeterminated voltage opens threshold value and open threshold value to the interval corresponding balance of predeterminated voltage being positioned at the interval both sides of the second predeterminated voltage and become large gradually.
In some embodiments of the invention, balance module 500 is also for carrying out in the process of electric quantity balancing to needing the cell carrying out electric quantity balancing, when judgement stops needing the cell carrying out electric quantity balancing to carry out electric quantity balancing when meeting the following conditions according to the first balance unlatching threshold value:
There is terminal voltage in the terminal voltage of multiple cell and be greater than the terminal voltage that first threshold or terminal voltage be less than Second Threshold, first threshold is greater than Second Threshold, such as when the terminal voltage of some cells is greater than 4.2V or is less than 2.8V, stop needing the cell carrying out electric quantity balancing to carry out electric quantity balancing.
The temperature of battery pack is higher than the first preset temperature or lower than the second preset temperature, first preset temperature is greater than the second preset temperature, such as when the working temperature of battery pack is higher than 50 DEG C or lower than 0 DEG C, stop needing the cell carrying out electric quantity balancing to carry out electric quantity balancing.
Carry out charge/discharge current in the process of electric quantity balancing higher than the first predetermined current, such as, when the charge/discharge current of battery pack is higher than 6C.
According to the cell balance control system of battery pack of the present invention, choose the foundation of cell terminal voltage as electric quantity balancing, judge whether to exist the cell needing to carry out electric quantity balancing by terminal voltage and average terminal voltage, the balance selecting different electric quantity balancings for different battery pack average terminal voltage opens threshold value, effectively avoid the interference that the non-linear relation due to cell state-of-charge and terminal voltage is brought, make correct electric quantity balancing to determine, the first cell of the maximum absolute value of the difference of terminal voltage and average terminal voltage can be obtained from multiple cell by the judge module of the embodiment of the present invention, and judge whether to need to carry out electric quantity balancing, can stop needing the cell carrying out electric quantity balancing to carry out electric quantity balancing by the balance module of the embodiment of the present invention, ensure the safety of the process of electric quantity balancing.
The cell balance of the cell balance control system of battery pack controls implementation as shown in Figure 3, comprises the following steps:
Step S301: start cell balance control method, acquisition module 100 gathers the terminal voltage of multiple cell in battery pack.In one embodiment of the invention, take nominal voltage as the lithium battery of 3.7V be example, describe the cell balance control method of the battery pack of the embodiment of the present invention in detail.
Step S302: judge whether cell is in normal condition, when have the terminal voltage of cell too high or too low time, be then in abnormal state of affairs, perform step S304, otherwise perform step S303.
Step S303: do not carry out cell balance control method.
Step S304: computing module 200 obtains the average terminal voltage of battery pack according to the terminal voltage of multiple cell, interval the first corresponding balance of predeterminated voltage obtaining average terminal voltage place from multiple continuous print predeterminated voltage interval opens threshold value, wherein, the balance unlatching threshold value of the predeterminated voltage interval correspondence of the both sides in multiple continuous print predeterminated voltage interval is greater than the predeterminated voltage interval corresponding balance unlatching threshold value of the centre in multiple continuous print predeterminated voltage interval, when the average terminal voltage of battery pack is in different phase respectively, open threshold value by balance table 1 Suo Shi to determine the need of carrying out electric quantity balancing.When the average terminal voltage of battery pack is in different phase respectively, opens threshold value by balance table 1 Suo Shi and determine the need of carrying out electric quantity balancing.
Step S305: the first cell obtaining the maximum absolute value of the difference of terminal voltage and average terminal voltage from multiple cell.
Step S306: the absolute value of the difference that judge module 400 is more maximum and first balances opens threshold value.If the absolute value of maximum difference is greater than the first balance open threshold value, then judges to need to carry out electric quantity balancing to the first cell, perform step S307, otherwise judge there is not the cell needing to carry out electric quantity balancing, perform step S308.
Step S307: balance module 500 is opened threshold value according to the first balance and carried out electric quantity balancing to needing the cell carrying out electric quantity balancing.
Concrete, after the nominal voltage lithium battery group that is 3.7V is started working, first gather the terminal voltage of each cell and calculate the average terminal voltage of battery pack, average terminal voltage as calculated is 3.1V, now 1 known by tabling look-up, average terminal voltage is the first balance unlatching threshold value of the battery pack of 3.1V is 0.2V, now calculate the absolute value of the terminal voltage of each cell and the difference of average voltage 3.1V, if the absolute value that there is the difference of a certain cell and average terminal voltage is greater than 0.2V, then need to carry out electric quantity balancing to cell, if the absolute value that there is the difference of the terminal voltage of multiple cell is all greater than 0.2V, that cell then choosing the maximum absolute value of difference carries out electric quantity balancing, if there is no the cell that the absolute value of difference is greater than 0.2V does not then carry out electric quantity balancing.
Here it should be noted that, as can be seen from Table 1, the interval corresponding balance of each predeterminated voltage is opened threshold value and from multiple continuous print predeterminated voltage interval, is positioned at the interval corresponding balance of the second middle predeterminated voltage opens threshold value and open threshold value to the interval corresponding balance of predeterminated voltage being positioned at the interval both sides of the second predeterminated voltage and become large gradually.
Step S308: stop needing the cell carrying out electric quantity balancing to carry out electric quantity balancing.After battery pack receives shutoff instruction, electric quantity balancing terminates, otherwise battery pack gets back to the cell that initial condition continues to select to need electric quantity balancing.
Balance module 500 is carrying out in the process of electric quantity balancing according to the first balance unlatching threshold value to needing the cell carrying out electric quantity balancing, stops needing the cell carrying out electric quantity balancing to carry out electric quantity balancing when meeting the following conditions:
There is terminal voltage in the terminal voltage of multiple cell and be greater than the terminal voltage that first threshold or terminal voltage be less than Second Threshold, first threshold is greater than Second Threshold, such as when the terminal voltage of some cells is greater than 4.2V or is less than 2.8V, stop needing the cell carrying out electric quantity balancing to carry out electric quantity balancing.
The temperature of battery pack is higher than the first preset temperature or lower than the second preset temperature, first preset temperature is greater than the second preset temperature, such as when the working temperature of battery pack is higher than 50 DEG C or lower than 0 DEG C, stop needing the cell carrying out electric quantity balancing to carry out electric quantity balancing.
Carry out charge/discharge current in the process of electric quantity balancing higher than predetermined current, such as, when the charge/discharge current of battery pack is higher than 6C.
Cell balance according to battery pack of the present invention controls implementation, choose the foundation of cell terminal voltage as electric quantity balancing, judge whether to exist the cell needing to carry out electric quantity balancing by terminal voltage and average terminal voltage, the balance selecting different electric quantity balancings for different battery pack average terminal voltage opens threshold value, effectively avoid the interference that the non-linear relation due to cell state-of-charge and terminal voltage is brought, make correct electric quantity balancing to determine, the first cell choosing the maximum absolute value of the terminal voltage of cell and the difference of average terminal voltage in the process of electric quantity balancing balances, make the process of electric quantity balancing more targeted, can stop needing the cell carrying out electric quantity balancing to carry out electric quantity balancing in the process of electric quantity balancing, ensure the safety of the process of electric quantity balancing.
In the description of this specification, specific features, structure, material or feature that the description of reference term " embodiment ", " some embodiments ", " example ", " concrete example " or " some examples " etc. means to describe in conjunction with this embodiment or example are contained at least one embodiment of the present invention or example.In this manual, identical embodiment or example are not necessarily referred to the schematic representation of above-mentioned term.And the specific features of description, structure, material or feature can combine in an appropriate manner in any one or more embodiment or example.
Although illustrate and describe embodiments of the invention, those having ordinary skill in the art will appreciate that: can carry out multiple change, amendment, replacement and modification to these embodiments when not departing from principle of the present invention and aim, scope of the present invention is by claim and equivalency thereof.
Claims (8)
1. a cell balance control method for battery pack, is characterized in that, described battery pack comprises multiple cells of series connection, said method comprising the steps of:
Gather the terminal voltage of multiple cell in described battery pack;
The average terminal voltage of described battery pack is obtained according to the terminal voltage of multiple described cell;
Interval the first corresponding balance of predeterminated voltage obtaining described average terminal voltage place from multiple continuous print predeterminated voltage interval opens threshold value, wherein, the balance that the predeterminated voltage interval of the both sides in described multiple continuous print predeterminated voltage interval is corresponding opens the predeterminated voltage interval corresponding balance unlatching threshold value that threshold value is greater than the centre in described multiple continuous print predeterminated voltage interval;
Judge whether to exist according to the terminal voltage of described multiple cell and the average terminal voltage of described battery pack the cell needing to carry out electric quantity balancing; And
If existed, then open threshold value according to described first balance and electric quantity balancing is carried out to the described cell carrying out electric quantity balancing that needs.
2. method according to claim 1, it is characterized in that, wherein, the interval corresponding balance of each predeterminated voltage is opened threshold value and from described multiple continuous print predeterminated voltage interval, is positioned at the interval corresponding balance of the second middle predeterminated voltage opens threshold value and open threshold value to the interval corresponding balance of predeterminated voltage being positioned at the interval both sides of described second predeterminated voltage and become large gradually.
3. method according to claim 1, is characterized in that, describedly judges whether to exist according to the terminal voltage of described multiple cell and the average terminal voltage of described battery pack the cell needing to carry out electric quantity balancing, specifically comprises:
The first cell of the maximum absolute value of the difference of terminal voltage and described average terminal voltage is obtained from described multiple cell;
The absolute value of more described maximum difference and described first balances opens threshold value;
If the absolute value of described maximum difference is greater than described first balance open threshold value, then judges to need to carry out electric quantity balancing to described first cell, otherwise judge there is not the cell needing to carry out electric quantity balancing.
4. method according to claim 1, it is characterized in that, carrying out in the process of electric quantity balancing according to described first balance unlatching threshold value to the described cell carrying out electric quantity balancing that needs, also comprising and stop carrying out electric quantity balancing to the described cell carrying out electric quantity balancing that needs when meeting the following conditions:
There is terminal voltage in the terminal voltage of described multiple cell and be greater than the terminal voltage that first threshold or terminal voltage be less than Second Threshold, described first threshold is greater than described Second Threshold;
Or the temperature of described battery pack is higher than the first preset temperature or lower than the second preset temperature, and described first preset temperature is greater than described second preset temperature;
Or, described in carry out charge/discharge current in the process of electric quantity balancing higher than predetermined current.
5. a cell balance control system for battery pack, is characterized in that, described battery pack comprises multiple cells of series connection, and described system comprises:
Acquisition module, for gathering the terminal voltage of multiple cell in described battery pack;
Computing module, for obtaining the average terminal voltage of described battery pack according to the terminal voltage of multiple described cell;
Acquisition module, interval the first corresponding balance of predeterminated voltage for obtaining described average terminal voltage place from multiple continuous print predeterminated voltage interval opens threshold value, wherein, the balance that the predeterminated voltage interval of the both sides in described multiple continuous print predeterminated voltage interval is corresponding opens the predeterminated voltage interval corresponding balance unlatching threshold value that threshold value is greater than the centre in described multiple continuous print predeterminated voltage interval;
Judge module, for judging whether to exist according to the terminal voltage of described multiple cell and the average terminal voltage of described battery pack the cell needing to carry out electric quantity balancing; And
Balance module, when needing for judging to exist at described judge module the cell carrying out electric quantity balancing, opening threshold value according to described first balance and carrying out electric quantity balancing to the described cell carrying out electric quantity balancing that needs.
6. system according to claim 5, it is characterized in that, wherein, the interval corresponding balance of each predeterminated voltage is opened threshold value and from described multiple continuous print predeterminated voltage interval, is positioned at the interval corresponding balance of the second middle predeterminated voltage opens threshold value and open threshold value to the interval corresponding balance of predeterminated voltage being positioned at the interval both sides of described second predeterminated voltage and become large gradually.
7. system according to claim 5, it is characterized in that, described judge module is used for the first cell obtaining the maximum absolute value of the difference of terminal voltage and described average terminal voltage from described multiple cell, and the absolute value of more described difference and described first balances and opens threshold value, and when the absolute value of described difference is greater than described first balance unlatching threshold value, judge to need to carry out electric quantity balancing to described first cell, otherwise judge there is not the cell needing to carry out electric quantity balancing.
8. system according to claim 5, it is characterized in that, described balance module also for according to described first balance open threshold value carrying out in the process of electric quantity balancing to the described cell carrying out electric quantity balancing that needs, when judgement when meeting the following conditions stopping electric quantity balancing being carried out to the described cell carrying out electric quantity balancing that needs:
There is terminal voltage in the terminal voltage of described multiple cell and be greater than the terminal voltage that first threshold or terminal voltage be less than Second Threshold, described first threshold is greater than described Second Threshold;
Or the temperature of described battery pack is higher than the first preset temperature or lower than the second preset temperature, and described first preset temperature is greater than described second preset temperature;
Or, described in carry out charge/discharge current in the process of electric quantity balancing higher than the first predetermined current.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108063293A (en) * | 2016-11-09 | 2018-05-22 | 比亚迪股份有限公司 | Battery pack balancing control method and control system |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2051347A2 (en) * | 2007-10-15 | 2009-04-22 | Black & Decker, Inc. | Method for balancing cells in a battery pack |
| CN101777784A (en) * | 2010-03-17 | 2010-07-14 | 北汽福田汽车股份有限公司 | Equalizing charge device and equalizing charge method |
| WO2010079296A2 (en) * | 2009-01-12 | 2010-07-15 | Valeo Equipements Electriques Moteur | Method for controlling an energy storage unit in a vehicle micro-hybrid system |
| CN102868000A (en) * | 2012-09-05 | 2013-01-09 | 浙江众泰新能源汽车科技有限公司 | Power source balancing method of electric car |
| CN103051031A (en) * | 2013-01-06 | 2013-04-17 | 成都芯源***有限公司 | Equalization apparatus for battery pack and method thereof |
| JP2013152231A (en) * | 2009-02-27 | 2013-08-08 | Hitachi Ltd | Battery monitoring device |
| CN103323775A (en) * | 2012-03-20 | 2013-09-25 | 北汽福田汽车股份有限公司 | Balanced monitoring and test system used for battery module |
-
2013
- 2013-10-30 CN CN201310526210.XA patent/CN104600760B/en not_active Expired - Fee Related
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2051347A2 (en) * | 2007-10-15 | 2009-04-22 | Black & Decker, Inc. | Method for balancing cells in a battery pack |
| WO2010079296A2 (en) * | 2009-01-12 | 2010-07-15 | Valeo Equipements Electriques Moteur | Method for controlling an energy storage unit in a vehicle micro-hybrid system |
| JP2013152231A (en) * | 2009-02-27 | 2013-08-08 | Hitachi Ltd | Battery monitoring device |
| CN101777784A (en) * | 2010-03-17 | 2010-07-14 | 北汽福田汽车股份有限公司 | Equalizing charge device and equalizing charge method |
| CN103323775A (en) * | 2012-03-20 | 2013-09-25 | 北汽福田汽车股份有限公司 | Balanced monitoring and test system used for battery module |
| CN102868000A (en) * | 2012-09-05 | 2013-01-09 | 浙江众泰新能源汽车科技有限公司 | Power source balancing method of electric car |
| CN103051031A (en) * | 2013-01-06 | 2013-04-17 | 成都芯源***有限公司 | Equalization apparatus for battery pack and method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 吴铁洲: "HEV锂离子电池组管理关键技术研究", 《中国博士学位论文全文数据库》, 15 August 2011 (2011-08-15) * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108063293A (en) * | 2016-11-09 | 2018-05-22 | 比亚迪股份有限公司 | Battery pack balancing control method and control system |
| CN108063293B (en) * | 2016-11-09 | 2020-11-20 | 比亚迪股份有限公司 | Battery pack balance control method and control system |
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|---|---|
| CN104600760B (en) | 2016-12-07 |
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