CN114977387A - Battery pack unbalance calculation method and system - Google Patents
Battery pack unbalance calculation method and system Download PDFInfo
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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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- 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
- H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
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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
- H02J7/0029—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits
- H02J7/0031—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with safety or protection devices or circuits using battery or load disconnect circuits
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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Abstract
The invention provides a method and a system for calculating unbalance of a battery pack in the technical field of battery detection, wherein the method comprises the following steps: step S10, battery parameters of the battery pack including total voltage of the battery pack, maximum voltage of the battery cell and minimum voltage of the battery cell are obtained in real time; step S20, calculating the serial number of batteries and the average voltage of battery cores based on the battery parameters; step S30, calculating the unbalance degree in real time based on the battery parameters and the average voltage of the battery core; step S40, calculating the maximum deviation ratio based on the battery parameters; step S50, setting an imbalance alarm threshold, an imbalance protection threshold, a maximum deviation ratio alarm threshold, and a maximum deviation ratio protection threshold, and performing security monitoring on the imbalance and the maximum deviation ratio based on the imbalance alarm threshold, the imbalance protection threshold, the maximum deviation ratio alarm threshold, and the maximum deviation ratio protection threshold. The invention has the advantages that: the unbalance degree is calculated in real time, and the use safety of the battery pack is greatly improved.
Description
Technical Field
The invention relates to the technical field of battery detection, in particular to a method and a system for calculating imbalance degree of a battery pack.
Background
With the development of the new energy industry, in order to provide sufficient voltage for equipment, a battery pack is generally formed by connecting a plurality of single batteries (battery cells) in series and in parallel, and the capacity imbalance of the batteries directly affects the capacity of the whole battery pack and even causes a safety problem, so that the imbalance of the batteries is an important index for measuring the performance of the battery pack.
However, the conventional 27930 communication protocol does not give the number of series-connected batteries, only gives the highest voltage of the single batteries during the charging process, and does not give the lowest voltage of the single batteries, so that the imbalance degree cannot be calculated in real time, an imbalance degree curve cannot be drawn, and the performance of the battery pack cannot be evaluated.
Therefore, how to provide a method for calculating the imbalance degree of a battery pack to calculate the imbalance degree in real time and improve the safety of the battery pack in use becomes a technical problem to be solved urgently.
Disclosure of Invention
The technical problem to be solved by the present invention is to provide a method and a system for calculating the imbalance degree of a battery pack, so as to calculate the imbalance degree in real time and improve the safety of the battery pack in use.
In a first aspect, the present invention provides a method for calculating imbalance of a battery pack, including the steps of:
step S10, battery parameters of the battery pack including total voltage of the battery pack, maximum voltage of the battery cell and minimum voltage of the battery cell are acquired in real time through the CAN interface, and a battery parameter set is constructed based on the battery parameters;
step S20, calculating the serial number of batteries and the average voltage of battery cells based on the battery parameters;
step S30, calculating the unbalance degree in real time based on the battery parameters and the average voltage of the battery core;
step S40, calculating the maximum deviation proportion of the serial number of the batteries based on the battery parameters;
step S50, setting an unbalance alarm threshold, an unbalance protection threshold, a maximum deviation proportion alarm threshold and a maximum deviation proportion protection threshold, and carrying out safety monitoring on the unbalance and the maximum deviation proportion based on the unbalance alarm threshold, the unbalance protection threshold, the maximum deviation proportion alarm threshold and the maximum deviation proportion protection threshold;
step S60, selecting a group of battery parameters with the minimum voltage difference between the maximum voltage of the battery core and the minimum voltage of the battery core from the battery parameter set as updating parameters, updating the serial number of the batteries, the average voltage of the battery cores, the unbalance and the maximum deviation ratio based on the updating parameters, and drawing an unbalance curve.
Further, in step S20, the calculation formula of the number of series-connected batteries and the average cell voltage is as follows:
Sbat＝Round(Vbms/Vcell.max)；
Vcell.avg＝Vbms/Sbat；
wherein Sbat represents the number of series-connected batteries; vbms represents the total battery voltage; max represents the cell maximum voltage; avg represents the cell average voltage.
Further, in step S30, the calculation formula of the imbalance degree is:
Sbalance＝Vcell.dif.max/Vcell.avg*100％；
Vcell.dif.max＝(Vcell.max-Vcell.avg)*2；
wherein Squalance represents the degree of imbalance; vcell.dif.max represents the approximate maximum voltage difference of the battery cell; avg represents the cell average voltage; max represents the cell maximum voltage.
Further, in step S40, the maximum deviation ratio is calculated according to the following formula:
Emax＝max(A1，A2)*100％；
A1＝abs(Round(Vbms/Vcell.max)/Round(Vbms/Vcell.min))-1；
A2＝abs(Round(Vbms/Vcell.min)/Round(Vbms/Vcell.max))-1；
wherein Emax represents the maximum deviation ratio; vbms represents the total battery voltage; max represents the cell maximum voltage; min represents the cell minimum voltage.
Further, the step S50 is specifically:
setting an unbalance degree alarm threshold, an unbalance degree protection threshold, a maximum deviation proportion alarm threshold and a maximum deviation proportion protection threshold, wherein the unbalance degree protection threshold is larger than the unbalance degree alarm threshold, and the maximum deviation proportion protection threshold is larger than the maximum deviation proportion alarm threshold;
monitoring the unbalance degree and the maximum deviation proportion in real time, and prompting an abnormal alarm when the unbalance degree is between an unbalance degree alarm threshold and an unbalance degree protection threshold or the maximum deviation proportion is between a maximum deviation proportion alarm threshold and a maximum deviation proportion protection threshold;
and when the unbalance is greater than the unbalance protection threshold, or the maximum deviation ratio is greater than the maximum deviation ratio protection threshold, stopping the test or charging of the battery pack.
In a second aspect, the present invention provides a battery imbalance calculation system, including the following modules:
the battery parameter acquisition module is used for acquiring battery parameters of the battery pack including total voltage of the battery pack, maximum voltage of the battery cell and minimum voltage of the battery cell in real time through the CAN interface and constructing a battery parameter set based on the battery parameters;
the serial number and average voltage calculation module is used for calculating the serial number of the batteries and the average voltage of the battery cores based on the battery parameters;
the unbalance calculation module is used for calculating the unbalance in real time based on the battery parameters and the average voltage of the battery core;
the maximum deviation ratio calculation module is used for calculating the maximum deviation ratio of the serial number of the batteries based on the battery parameters;
the safety monitoring module is used for setting an unbalance alarm threshold, an unbalance protection threshold, a maximum deviation proportion alarm threshold and a maximum deviation proportion protection threshold, and carrying out safety monitoring on the unbalance and the maximum deviation proportion based on the unbalance alarm threshold, the unbalance protection threshold, the maximum deviation proportion alarm threshold and the maximum deviation proportion protection threshold;
and the data updating module is used for selecting a group of battery parameters with the minimum voltage difference between the maximum voltage and the minimum voltage of the battery core from the battery parameter set as updating parameters, updating the serial number of the batteries, the average voltage of the battery core, the imbalance and the maximum deviation ratio based on the updating parameters, and drawing an imbalance curve.
Further, in the serial number and average voltage calculation module, the calculation formulas of the battery serial number and the cell average voltage are as follows:
Sbat＝Round(Vbms/Vcell.max)；
Vcell.avg＝Vbms/Sbat；
wherein Sbat represents the number of series-connected batteries; vbms represents the total battery voltage; max represents the cell maximum voltage; avg represents the cell average voltage.
Further, in the imbalance degree calculating module, the imbalance degree calculating formula is as follows:
Sbalance＝Vcell.dif.max/Vcell.avg*100％；
Vcell.dif.max＝(Vcell.max-Vcell.avg)*2；
wherein Squalance represents the degree of imbalance; vcell.dif.max represents the approximate maximum voltage difference of the battery cell; avg represents the cell average voltage; max represents the cell maximum voltage.
Further, in the maximum deviation ratio calculation module, the calculation formula of the maximum deviation ratio is as follows:
Emax＝max(A1，A2)*100％；
A1＝abs(Round(Vbms/Vcell.max)/Round(Vbms/Vcell.min))-1；
A2＝abs(Round(Vbms/Vcell.min)/Round(Vbms/Vcell.max))-1；
wherein Emax represents the maximum deviation ratio; vbms represents the total battery voltage; max represents the cell maximum voltage; min represents the cell minimum voltage.
Further, the safety monitoring module specifically includes:
setting an unbalance degree alarm threshold, an unbalance degree protection threshold, a maximum deviation proportion alarm threshold and a maximum deviation proportion protection threshold, wherein the unbalance degree protection threshold is larger than the unbalance degree alarm threshold, and the maximum deviation proportion protection threshold is larger than the maximum deviation proportion alarm threshold;
monitoring the unbalance degree and the maximum deviation proportion in real time, and prompting an abnormal alarm when the unbalance degree is between an unbalance degree alarm threshold and an unbalance degree protection threshold or the maximum deviation proportion is between a maximum deviation proportion alarm threshold and a maximum deviation proportion protection threshold;
and when the unbalance is greater than the unbalance protection threshold, or the maximum deviation ratio is greater than the maximum deviation ratio protection threshold, stopping the test or charging of the battery pack.
The invention has the advantages that:
1. the battery series number is calculated by acquiring the total voltage of the battery pack and the maximum voltage of the battery cell in real time, the average voltage of the battery cell is calculated based on the total voltage of the battery pack and the battery series number, the approximate maximum voltage difference of the battery cell is calculated based on the average voltage of the battery cell and the maximum voltage of the battery cell, and finally the unbalance degree is calculated based on the approximate maximum voltage difference of the battery cell and the average voltage of the battery cell, namely the unbalance degree of the battery pack is calculated in real time.
2. The maximum deviation proportion is calculated by acquiring the total voltage of the battery pack, the maximum voltage of the battery cell and the minimum voltage of the battery cell in real time, safety monitoring is carried out on the unbalance degree and the maximum deviation proportion through the set unbalance degree alarm threshold value, the unbalance degree protection threshold value, the maximum deviation proportion alarm threshold value and the maximum deviation proportion protection threshold value, when the value exceeds the corresponding threshold value, abnormal alarm is carried out or the battery pack is stopped to be tested or charged, and therefore the use safety of the battery pack is greatly improved.
3. The battery parameter set is used for selecting a group of battery parameters with the minimum voltage difference between the maximum voltage of the battery core and the minimum voltage of the battery core as update parameters, updating the serial number of the batteries through the update parameters, updating the average voltage, the imbalance degree and the maximum deviation proportion of the battery core based on the updated serial number of the batteries and the update parameters, and drawing an imbalance degree curve, so that the imbalance degree and the maximum deviation proportion can be continuously corrected, the calculation accuracy of the imbalance degree and the maximum deviation proportion is guaranteed, the maximum imbalance degree, the minimum imbalance degree and the average imbalance degree can be obtained through the drawn imbalance degree curve, the omnibearing safety monitoring of the battery pack is facilitated, and the use safety of the battery pack is further improved.
Drawings
The invention will be further described with reference to the following examples with reference to the accompanying drawings.
Fig. 1 is a flowchart of a battery imbalance calculation method according to the present invention.
Fig. 2 is a schematic structural diagram of a system for calculating imbalance of a battery pack according to the present invention.
Detailed Description
The technical scheme in the embodiment of the application has the following general idea: calculating the battery series number through the total voltage of the battery pack and the maximum voltage of the battery cell, calculating the average voltage of the battery cell based on the total voltage of the battery pack and the battery series number, calculating the approximate maximum voltage difference of the battery cell based on the average voltage of the battery cell and the maximum voltage of the battery cell, and finally calculating the unbalance degree based on the approximate maximum voltage difference of the battery cell and the average voltage of the battery cell; and selecting a group of battery parameters with the minimum voltage difference between the maximum voltage of the battery core and the minimum voltage of the battery core from the battery parameter set as updating parameters, and updating the serial number of the batteries through the updating parameters so as to update the imbalance degree.
Referring to fig. 1 to 2, a preferred embodiment of a method for calculating imbalance of a battery pack according to the present invention includes the following steps:
step S10, battery parameters of the battery pack including total voltage of the battery pack, maximum voltage of a battery cell and minimum voltage of the battery cell are obtained in real time from a BMS of the battery pack through a CAN interface, and a battery parameter set is constructed based on each battery parameter;
step S20, calculating the serial number of batteries and the average voltage of battery cells based on the battery parameters;
step S30, calculating the unbalance degree in real time based on the battery parameters and the average voltage of the battery core;
step S40, calculating the maximum deviation proportion of the serial number of the batteries based on the battery parameters;
step S50, setting an unbalance alarm threshold, an unbalance protection threshold, a maximum deviation proportion alarm threshold and a maximum deviation proportion protection threshold, and carrying out safety monitoring on the unbalance and the maximum deviation proportion based on the unbalance alarm threshold, the unbalance protection threshold, the maximum deviation proportion alarm threshold and the maximum deviation proportion protection threshold;
step S60, selecting a group of battery parameters with the minimum voltage difference between the maximum voltage and the minimum voltage of the battery core from the battery parameter set as updating parameters, updating the serial number of the batteries, the average voltage of the battery core, the imbalance degree and the maximum deviation ratio based on the updating parameters, and drawing an imbalance degree curve. Namely, the battery series number is updated by using a group of battery parameters with the minimum voltage difference between the maximum voltage and the minimum voltage of the battery cell, so as to reduce the error of the battery series number.
In step S20, the calculation formulas of the number of series-connected batteries and the average cell voltage are as follows:
Sbat＝Round(Vbms/Vcell.max)；
Vcell.avg＝Vbms/Sbat；
wherein Sbat represents the number of series-connected batteries; vbms represents the total battery voltage; max represents the cell maximum voltage; avg represents the cell average voltage.
In step S30, the calculation formula of the imbalance degree is:
Sbalance＝Vcell.dif.max/Vcell.avg*100％；
max ═ vcell.max-vcell.avg) × 2; because the differential pressure has positive and negative directions, twice of the difference value between the maximum voltage of the cell and the average voltage of the cell is taken as the approximate maximum differential pressure of the cell;
wherein Squalance represents the degree of imbalance; vcell.dif.max represents the approximate maximum voltage difference of the battery cell; avg represents the cell average voltage; max represents the cell maximum voltage.
In step S40, the maximum deviation ratio is calculated according to the following formula:
Emax＝max(A1，A2)*100％；
A1＝abs(Round(Vbms/Vcell.max)/Round(Vbms/Vcell.min))-1；
A2＝abs(Round(Vbms/Vcell.min)/Round(Vbms/Vcell.max))-1；
wherein Emax represents the maximum deviation ratio; vbms represents the total battery voltage; max represents the cell maximum voltage; min represents the cell minimum voltage.
For example, if a 200-string battery pack includes 100 strings of 3V batteries, 100 strings of 4V batteries, and 100 strings of 300V batteries, and 100 strings of 400V batteries, the total voltage of the battery pack is 700V, the maximum voltage of the battery cells is 4V, and the minimum voltage of the battery cells is 3V; the deviation was-12.5% for the string calculated with 4V, 16.5% for the string calculated with 3V, and the final maximum deviation ratio was 16.5%.
The step S50 specifically includes:
setting an unbalance degree alarm threshold, an unbalance degree protection threshold, a maximum deviation proportion alarm threshold and a maximum deviation proportion protection threshold, wherein the unbalance degree protection threshold is larger than the unbalance degree alarm threshold, and the maximum deviation proportion protection threshold is larger than the maximum deviation proportion alarm threshold;
monitoring the unbalance degree and the maximum deviation proportion in real time, and prompting an abnormal alarm when the unbalance degree is between an unbalance degree alarm threshold and an unbalance degree protection threshold or the maximum deviation proportion is between a maximum deviation proportion alarm threshold and a maximum deviation proportion protection threshold;
and when the unbalance is greater than the unbalance protection threshold, or the maximum deviation ratio is greater than the maximum deviation ratio protection threshold, stopping the test or charging of the battery pack.
The invention discloses a preferred embodiment of a battery imbalance calculation system, which comprises the following modules:
the battery parameter acquisition module is used for acquiring battery parameters of the battery pack, including total voltage of the battery pack, maximum voltage of a battery cell and minimum voltage of the battery cell, from a BMS (battery management system) of the battery pack in real time through a CAN (controller area network) interface, and constructing a battery parameter set based on each battery parameter;
the serial number and average voltage calculation module is used for calculating the serial number of the batteries and the average voltage of the battery cores based on the battery parameters;
the unbalance calculation module is used for calculating the unbalance in real time based on the battery parameters and the average voltage of the battery core;
the maximum deviation ratio calculation module is used for calculating the maximum deviation ratio of the serial number of the batteries based on the battery parameters;
the safety monitoring module is used for setting an unbalance alarm threshold, an unbalance protection threshold, a maximum deviation proportion alarm threshold and a maximum deviation proportion protection threshold, and carrying out safety monitoring on the unbalance and the maximum deviation proportion based on the unbalance alarm threshold, the unbalance protection threshold, the maximum deviation proportion alarm threshold and the maximum deviation proportion protection threshold;
and the data updating module is used for selecting a group of battery parameters with the minimum voltage difference between the maximum voltage of the battery core and the minimum voltage of the battery core from the battery parameter set as updating parameters, updating the serial number of the batteries, the average voltage of the battery cores, the unbalance and the maximum deviation ratio based on the updating parameters, and drawing an unbalance curve. Namely, the battery series number is updated by using a group of battery parameters with the minimum voltage difference between the maximum voltage and the minimum voltage of the battery cell, so as to reduce the error of the battery series number.
In the serial number and average voltage calculation module, the calculation formulas of the battery serial number and the cell average voltage are as follows:
Sbat＝Round(Vbms/Vcell.max)；
Vcell.avg＝Vbms/Sbat；
wherein Sbat represents the number of series-connected batteries; vbms represents the total battery voltage; max represents the cell maximum voltage; avg represents the cell average voltage.
In the imbalance calculation module, the calculation formula of the imbalance is as follows:
Sbalance＝Vcell.dif.max/Vcell.avg*100％；
max ═ vcell.max-vcell.avg) × 2; because the differential pressure has positive and negative directions, twice of the difference value between the maximum voltage of the cell and the average voltage of the cell is taken as the approximate maximum differential pressure of the cell;
wherein Squalance represents the degree of imbalance; vcell.dif.max represents the approximate maximum voltage difference of the battery cell; avg represents the cell average voltage; max represents the cell maximum voltage.
In the maximum deviation ratio calculation module, the calculation formula of the maximum deviation ratio is as follows:
Emax＝max(A1，A2)*100％；
A1＝abs(Round(Vbms/Vcell.max)/Round(Vbms/Vcell.min))-1；
A2＝abs(Round(Vbms/Vcell.min)/Round(Vbms/Vcell.max))-1；
wherein Emax represents the maximum deviation ratio; vbms represents the total battery voltage; max represents the cell maximum voltage; min represents the cell minimum voltage.
For example, if a 200-string battery pack includes 100 strings of 3V batteries, the voltage of the 100 strings is 300V, and the voltage of the 100 strings is 400V, the total voltage of the battery pack is 700V, the maximum voltage of the battery cells is 4V, and the minimum voltage of the battery cells is 3V; the deviation was-12.5% for the string calculated with 4V, 16.5% for the string calculated with 3V, and the final maximum deviation ratio was 16.5%.
The safety monitoring module is specifically as follows:
setting an unbalance degree alarm threshold, an unbalance degree protection threshold, a maximum deviation proportion alarm threshold and a maximum deviation proportion protection threshold, wherein the unbalance degree protection threshold is larger than the unbalance degree alarm threshold, and the maximum deviation proportion protection threshold is larger than the maximum deviation proportion alarm threshold;
monitoring the unbalance degree and the maximum deviation proportion in real time, and prompting an abnormal alarm when the unbalance degree is between an unbalance degree alarm threshold and an unbalance degree protection threshold or the maximum deviation proportion is between a maximum deviation proportion alarm threshold and a maximum deviation proportion protection threshold;
and when the unbalance is greater than the unbalance protection threshold, or the maximum deviation ratio is greater than the maximum deviation ratio protection threshold, stopping the test or charging of the battery pack.
In summary, the invention has the advantages that:
1. the battery series number is calculated by acquiring the total voltage of the battery pack and the maximum voltage of the battery cell in real time, the average voltage of the battery cell is calculated based on the total voltage of the battery pack and the battery series number, the approximate maximum voltage difference of the battery cell is calculated based on the average voltage of the battery cell and the maximum voltage of the battery cell, and the unbalance degree is calculated based on the approximate maximum voltage difference of the battery cell and the average voltage of the battery cell, namely the unbalance degree of the battery pack is calculated in real time.
2. The maximum deviation proportion is calculated by acquiring the total voltage of the battery pack, the maximum voltage of the battery cell and the minimum voltage of the battery cell in real time, safety monitoring is carried out on the unbalance degree and the maximum deviation proportion through the set unbalance degree alarm threshold value, the unbalance degree protection threshold value, the maximum deviation proportion alarm threshold value and the maximum deviation proportion protection threshold value, when the value exceeds the corresponding threshold value, abnormal alarm is carried out or the battery pack is stopped to be tested or charged, and therefore the use safety of the battery pack is greatly improved.
3. The battery parameter set is used for selecting a group of battery parameters with the minimum voltage difference between the maximum voltage of the battery core and the minimum voltage of the battery core as update parameters, updating the serial number of the batteries through the update parameters, updating the average voltage, the imbalance degree and the maximum deviation proportion of the battery core based on the updated serial number of the batteries and the update parameters, and drawing an imbalance degree curve, so that the imbalance degree and the maximum deviation proportion can be continuously corrected, the calculation accuracy of the imbalance degree and the maximum deviation proportion is guaranteed, the maximum imbalance degree, the minimum imbalance degree and the average imbalance degree can be obtained through the drawn imbalance degree curve, the omnibearing safety monitoring of the battery pack is facilitated, and the use safety of the battery pack is further improved.
Although specific embodiments of the invention have been described above, it will be understood by those skilled in the art that the specific embodiments described are illustrative only and are not limiting upon the scope of the invention, and that equivalent modifications and variations can be made by those skilled in the art without departing from the spirit of the invention, which is to be limited only by the appended claims.
Claims (10)
1. A battery imbalance calculation method, characterized by: the method comprises the following steps:
step S10, battery parameters of the battery pack including total voltage of the battery pack, maximum voltage of the battery cell and minimum voltage of the battery cell are acquired in real time through the CAN interface, and a battery parameter set is constructed based on the battery parameters;
step S20, calculating the serial number of batteries and the average voltage of battery cells based on the battery parameters;
step S30, calculating the unbalance degree in real time based on the battery parameters and the average voltage of the battery core;
step S40, calculating the maximum deviation proportion of the serial number of the batteries based on the battery parameters;
step S50, setting an unbalance alarm threshold, an unbalance protection threshold, a maximum deviation proportion alarm threshold and a maximum deviation proportion protection threshold, and carrying out safety monitoring on the unbalance and the maximum deviation proportion based on the unbalance alarm threshold, the unbalance protection threshold, the maximum deviation proportion alarm threshold and the maximum deviation proportion protection threshold;
step S60, selecting a group of battery parameters with the minimum voltage difference between the maximum voltage of the battery core and the minimum voltage of the battery core from the battery parameter set as updating parameters, updating the serial number of the batteries, the average voltage of the battery cores, the unbalance and the maximum deviation ratio based on the updating parameters, and drawing an unbalance curve.
2. The battery imbalance calculation method according to claim 1, wherein: in step S20, the calculation formulas of the number of series-connected batteries and the average cell voltage are as follows:
Sbat＝Round(Vbms/Vcell.max)；
Vcell.avg＝Vbms/Sbat；
wherein Sbat represents the number of series-connected batteries; vbms represents the total battery voltage; max represents the cell maximum voltage; avg represents the cell average voltage.
3. The battery imbalance calculation method according to claim 1, wherein: in step S30, the calculation formula of the imbalance degree is:
Sbalance＝Vcell.dif.max/Vcell.avg*100％；
Vcell.dif.max＝(Vcell.max-Vcell.avg)*2；
wherein Squalance represents the degree of imbalance; vcell.dif.max represents the approximate maximum voltage difference of the battery cell; avg represents the cell average voltage; max represents the cell maximum voltage.
4. The battery imbalance calculation method according to claim 1, wherein: in step S40, the maximum deviation ratio is calculated by the following formula:
Emax＝max(A1，A2)*100％；
A1＝abs(Round(Vbms/Vcell.max)/Round(Vbms/Vcell.min))-1；
A2＝abs(Round(Vbms/Vcell.min)/Round(Vbms/Vcell.max))-1；
wherein Emax represents the maximum deviation ratio; vbms represents the total battery voltage; max represents the cell maximum voltage; min represents the cell minimum voltage.
5. The battery imbalance calculation method according to claim 1, wherein: the step S50 specifically includes:
setting an unbalance degree alarm threshold, an unbalance degree protection threshold, a maximum deviation proportion alarm threshold and a maximum deviation proportion protection threshold, wherein the unbalance degree protection threshold is larger than the unbalance degree alarm threshold, and the maximum deviation proportion protection threshold is larger than the maximum deviation proportion alarm threshold;
monitoring the unbalance degree and the maximum deviation proportion in real time, and prompting an abnormal alarm when the unbalance degree is between an unbalance degree alarm threshold and an unbalance degree protection threshold or the maximum deviation proportion is between a maximum deviation proportion alarm threshold and a maximum deviation proportion protection threshold;
and when the unbalance is greater than the unbalance protection threshold, or the maximum deviation ratio is greater than the maximum deviation ratio protection threshold, stopping the test or charging of the battery pack.
6. A system for calculating imbalance of a battery pack, comprising: the system comprises the following modules:
the battery parameter acquisition module is used for acquiring battery parameters of the battery pack including total voltage of the battery pack, maximum voltage of the battery cell and minimum voltage of the battery cell in real time through the CAN interface and constructing a battery parameter set based on the battery parameters;
the serial number and average voltage calculation module is used for calculating the serial number of the batteries and the average voltage of the battery cores based on the battery parameters;
the unbalance calculation module is used for calculating the unbalance in real time based on the battery parameters and the average voltage of the battery core;
the maximum deviation ratio calculation module is used for calculating the maximum deviation ratio of the serial number of the batteries based on the battery parameters;
the safety monitoring module is used for setting an unbalance alarm threshold, an unbalance protection threshold, a maximum deviation proportion alarm threshold and a maximum deviation proportion protection threshold, and carrying out safety monitoring on the unbalance and the maximum deviation proportion based on the unbalance alarm threshold, the unbalance protection threshold, the maximum deviation proportion alarm threshold and the maximum deviation proportion protection threshold;
and the data updating module is used for selecting a group of battery parameters with the minimum voltage difference between the maximum voltage of the battery core and the minimum voltage of the battery core from the battery parameter set as updating parameters, updating the serial number of the batteries, the average voltage of the battery cores, the unbalance and the maximum deviation ratio based on the updating parameters, and drawing an unbalance curve.
7. The battery imbalance calculation system according to claim 6, wherein: in the serial number and average voltage calculation module, the calculation formulas of the battery serial number and the cell average voltage are as follows:
Sbat＝Round(Vbms/Vcell.max)；
Vcell.avg＝Vbms/Sbat；
wherein Sbat represents the number of series-connected batteries; vbms represents the total battery voltage; max represents the cell maximum voltage; avg represents the cell average voltage.
8. The battery imbalance calculation system according to claim 6, wherein: in the imbalance calculation module, the calculation formula of the imbalance is as follows:
Sbalance＝Vcell.dif.max/Vcell.avg*100％；
Vcell.dif.max＝(Vcell.max-Vcell.avg)*2；
wherein Squalance represents the degree of imbalance; vcell.dif.max represents the approximate maximum voltage difference of the battery cell; avg represents the cell average voltage; max represents the cell maximum voltage.
9. The battery imbalance calculation system according to claim 6, wherein: in the maximum deviation ratio calculation module, the calculation formula of the maximum deviation ratio is as follows:
Emax＝max(A1，A2)*100％；
A1＝abs(Round(Vbms/Vcell.max)/Round(Vbms/Vcell.min))-1；
A2＝abs(Round(Vbms/Vcell.min)/Round(Vbms/Vcell.max))-1；
wherein Emax represents the maximum deviation ratio; vbms represents the total battery voltage; max represents the cell maximum voltage; min represents the cell minimum voltage.
10. The battery imbalance calculation system according to claim 6, wherein: the safety monitoring module is specifically as follows:
setting an unbalance degree alarm threshold, an unbalance degree protection threshold, a maximum deviation proportion alarm threshold and a maximum deviation proportion protection threshold, wherein the unbalance degree protection threshold is larger than the unbalance degree alarm threshold, and the maximum deviation proportion protection threshold is larger than the maximum deviation proportion alarm threshold;
monitoring the unbalance degree and the maximum deviation proportion in real time, and prompting an abnormal alarm when the unbalance degree is between an unbalance degree alarm threshold and an unbalance degree protection threshold or the maximum deviation proportion is between a maximum deviation proportion alarm threshold and a maximum deviation proportion protection threshold;
and when the unbalance is greater than the unbalance protection threshold, or the maximum deviation proportion is greater than the maximum deviation proportion protection threshold, stopping the test or charging of the battery pack.
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1976090A1 (en) * | 2007-03-28 | 2008-10-01 | Kabushiki Kaisha Toshiba | Protection device for assembled battery, and battery pack unit |
| JP2009081989A (en) * | 2007-09-25 | 2009-04-16 | O2 Micro Inc | System and method for cell balancing |
| CN109515251A (en) * | 2018-12-26 | 2019-03-26 | 中国船舶重工集团公司第七〇九研究所 | A kind of hybrid power lithium battery group balance control method |
| CN109713740A (en) * | 2018-10-24 | 2019-05-03 | 北京天势新能源技术有限公司 | A kind of the active equalization framework and active equalization method of battery management system |
| CN113054706A (en) * | 2021-03-18 | 2021-06-29 | 中国第一汽车股份有限公司 | Balance monitoring control system and method for power battery |
-
2022
- 2022-05-24 CN CN202210568181.2A patent/CN114977387B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1976090A1 (en) * | 2007-03-28 | 2008-10-01 | Kabushiki Kaisha Toshiba | Protection device for assembled battery, and battery pack unit |
| JP2009081989A (en) * | 2007-09-25 | 2009-04-16 | O2 Micro Inc | System and method for cell balancing |
| CN109713740A (en) * | 2018-10-24 | 2019-05-03 | 北京天势新能源技术有限公司 | A kind of the active equalization framework and active equalization method of battery management system |
| CN109515251A (en) * | 2018-12-26 | 2019-03-26 | 中国船舶重工集团公司第七〇九研究所 | A kind of hybrid power lithium battery group balance control method |
| CN113054706A (en) * | 2021-03-18 | 2021-06-29 | 中国第一汽车股份有限公司 | Balance monitoring control system and method for power battery |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN119134612A (en) * | 2024-11-15 | 2024-12-13 | 杭州煦达新能源科技有限公司 | Battery system balancing method and device based on battery cell working status |
| CN119134612B (en) * | 2024-11-15 | 2025-03-28 | 杭州煦达新能源科技有限公司 | Battery system equalization method and device based on working state of battery core |
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