CN110416646B - Method and device for controlling charge and discharge of battery pack - Google Patents
Method and device for controlling charge and discharge of battery pack Download PDFInfo
- Publication number
- CN110416646B CN110416646B CN201810389635.3A CN201810389635A CN110416646B CN 110416646 B CN110416646 B CN 110416646B CN 201810389635 A CN201810389635 A CN 201810389635A CN 110416646 B CN110416646 B CN 110416646B
- Authority
- CN
- China
- Prior art keywords
- battery
- battery module
- charge
- discharge
- battery modules
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/44—Methods for charging or discharging
- H01M10/441—Methods for charging or discharging for several batteries or cells simultaneously or sequentially
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M10/00—Secondary cells; Manufacture thereof
- H01M10/42—Methods or arrangements for servicing or maintenance of secondary cells or secondary half-cells
- H01M10/44—Methods for charging or discharging
- H01M10/443—Methods for charging or discharging in response to temperature
-
- 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
-
- 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
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
According to the present invention, there is provided a method of controlling charge and discharge of a battery pack, the method comprising: calculating the degradation state of each battery module according to the real-time charge and discharge state of each battery module for a plurality of battery modules to be subjected to charge and discharge control in the battery pack; calculating a difference between the degradation state of each battery module and a preset degradation set value; if the difference between the degradation state of at least one battery module and the preset degradation set value is greater than a preset threshold value, calculating an optimal control parameter value for a temperature difference between the temperature of each battery module and the temperature of the battery module as a reference; generating charge and discharge commands for each of the plurality of battery modules using the calculated optimal control parameter value and the current actually measured temperature difference; and controlling charge and discharge of each battery module using the charge and discharge command generated for each battery module of the plurality of battery modules.
Description
Technical Field
The present invention relates to a method and apparatus for charging and discharging a battery pack, which can generate a charge and discharge command for each battery module in the battery pack through an optimal control parameter value, thereby equalizing charge and discharge of the battery pack to improve overall performance or lifetime.
Background
Degradation of the battery is the most important factor limiting battery applications. In a battery pack including a plurality of battery cells, there is a tendency that the battery pack is in a state of charge and discharge and in a state of deterioration in practical use, and local deterioration is accelerated to cause a decrease in overall performance.
The prior art proposes methods for judging the degradation condition of some battery cells by using a hardware circuit or a control strategy, and avoiding the acceleration of the overall degradation or the reduction of the reliability by isolating some battery cells in a poor state.
For example, patent document 1 proposes a method of balancing each battery module according to a real-time charge-discharge state, SOC (state of charge) and temperature of the battery. For example, reference 1 discloses a state management device for managing states of a plurality of power storage elements connected in series, the state management device including: a voltage measurement unit that measures the voltage of each of the power storage elements individually; a timer unit that counts a time difference from when a time rate of change of a voltage of any one of the power storage elements reaches a reference value to when a time rate of change of a voltage of the other power storage element reaches the reference value; a discharge unit that individually discharges the respective power storage elements; and an equalization control unit that controls the discharge unit by using the time difference.
Patent document 2 proposes a method of equalizing degradation performance of the entire battery pack. Specifically, in the comparison document 2, a battery degradation rule is obtained in advance, and charge and discharge of each battery unit in the battery pack are controlled by using the battery degradation rule obtained in advance, so that degradation performance of the whole battery pack is equalized.
Prior art literature
Patent literature
Patent document 1: CN103001277B
Patent document 2: W02016055806A1
Disclosure of Invention
Technical problem to be solved by the invention
However, the technique proposed in patent document 1 is only a measure designed to ensure the safety of the battery pack, and the battery having poor performance may be isolated, but the deterioration imbalance of each battery cell cannot be avoided. In addition, the prior art can only be applied to the battery pack formed by the same type of battery modules, and the charge and discharge strategies of the battery pack do not consider the influence of external environments on battery degradation.
Patent document 2 discloses information such as degradation model, capacity, battery type, etc. of each battery cell in detail, but these are difficult to obtain in practical application. The degradation model established according to the data acquired by the battery in the standard experiment is not matched with the actual application scene, and the complete influence mode of the external environment on the battery degradation is difficult to establish. The charge-discharge strategy does not consider the influence of the external environment on the battery degradation.
Solution to the technical problem
The present invention has been made to overcome the above-mentioned drawbacks of the prior art. It is therefore an object of the present invention to provide a method and apparatus for charging and discharging a battery pack, which can generate charge and discharge commands for each battery module in the battery pack by optimizing control parameter values, thereby equalizing charge and discharge of the battery pack to improve overall performance or lifetime.
In order to solve the above technical problems, according to the present invention, there is provided a method for controlling charge and discharge of a battery pack, the method comprising: calculating the degradation state of each battery module according to the real-time charge and discharge state of each battery module for a plurality of battery modules to be subjected to charge and discharge control in the battery pack; calculating a difference between a degradation state of each battery module and a degradation set value preset for each battery module; if the difference between the degradation state of at least one of the plurality of battery modules and the degradation set value preset for that battery module is greater than a preset threshold value, calculating an optimal control parameter value for the temperature difference between the temperature of each of the plurality of battery modules and the temperature of the battery module that is the reference among the plurality of battery modules; generating charge and discharge commands for each of the plurality of battery modules using the calculated optimal control parameter value and a temperature difference between the temperature of each of the battery modules currently actually measured and the temperature of the battery module as a reference; and controlling charge and discharge of each of the plurality of battery modules using charge and discharge commands generated for each of the battery modules.
Preferably, the battery module as a reference of the plurality of battery modules is a battery module that does not perform charge-discharge control.
Preferably, the battery module serving as a reference of the plurality of battery modules is any one of the plurality of battery modules to be subjected to charge-discharge control.
Preferably, the degradation state of each battery module is obtained by calculating the internal resistance of the battery module using the current and voltage of the battery module.
Preferably, in the case where the battery module includes a plurality of battery cells, the current and the voltage of the battery module are average values or maximum values of the current and the voltage of each battery cell included in the battery module.
Preferably, in the case where the battery module includes a plurality of battery cells, the temperature of the battery module is an average value or a maximum value of the temperatures of the respective battery cells included in the battery module.
Preferably, the optimal control parameter value is calculated based on an optimization algorithm including a plurality of iterative calculations, an input amount of the optimization algorithm being a degradation state of a plurality of battery modules to be charge-discharge controlled, a lifetime setting value of the plurality of battery modules to be charge-discharge controlled, an optimizable argument of the optimization algorithm being an optimal temperature difference between a temperature of the plurality of battery modules to be charge-discharge controlled and a temperature of the battery module as a reference, an objective function of the optimization algorithm being a sum of differences between the degradation state of the plurality of battery modules to be charge-discharge controlled and the lifetime setting value.
Preferably, the plurality of iterations are performed at a degradation calculation period that is an integer multiple of a period value of a sampling period in which the real-time charge-discharge states of the battery modules are sampled, each iteration calculation being based on the real-time charge-discharge states of the respective battery modules and a history state of previous iteration calculations.
In addition, according to the present invention, there is also provided an apparatus for controlling charge and discharge of a battery pack, the apparatus comprising: a unit that calculates a degradation state of each battery module from a real-time charge/discharge state of each battery module for a plurality of battery modules to be charge/discharge controlled in the battery pack; a unit that calculates a difference between a degradation state of each battery module and a degradation set value preset for each battery module; a means for calculating an optimal control parameter value for a temperature difference between a temperature of each of the plurality of battery modules and a temperature of a battery module serving as a reference among the plurality of battery modules, when a difference between a degradation state of at least one of the plurality of battery modules and a degradation set value preset for the battery module is greater than a preset threshold; a unit that generates charge/discharge commands for each of the plurality of battery modules using the calculated optimal control parameter value and a temperature difference between the temperature of each of the battery modules currently actually measured and the temperature of the battery module as a reference; and a unit that controls charge and discharge of each of the plurality of battery modules using a charge and discharge command generated for each of the battery modules.
Effects of the invention
According to the invention, the charge and discharge command for each battery module in the battery pack can be generated by the optimal control parameter value, so that the charge and discharge of the battery pack are balanced, and the overall performance or service life is improved.
Drawings
The above objects and advantages of the present invention will become more apparent by reference to the detailed description of the drawings in which:
fig. 1 is a schematic block diagram showing a system for charge and discharge control of a battery pack according to embodiment 1 of the present invention.
Fig. 2 is a flowchart illustrating a method of charge and discharge control of a battery pack according to the present invention.
Fig. 3 is a schematic diagram for explaining calculation of the battery degradation state.
Fig. 4 is a schematic block diagram illustrating charge-discharge dynamic charge-discharge control logic according to the present invention.
Fig. 5A is a transfer function block diagram of an algorithm employed by the controller.
Fig. 5B is a transfer function block diagram of another algorithm employed by the controller.
Fig. 6 is a flowchart showing a process of updating the optimal control parameter values required for the battery dynamic charge and discharge control logic.
Fig. 7 is a schematic diagram for explaining a process of calculating optimal control parameter values required for the battery dynamic charge-discharge control logic.
Fig. 8 is a schematic block diagram showing a system for charge and discharge control of a battery pack according to embodiment 2 of the present invention.
Detailed Description
Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. In the drawings, like elements will be represented by like reference numerals or numbers. In addition, in the following description of the present invention, a detailed description of known functions and configurations will be omitted so as not to obscure the subject matter of the present invention.
It should be understood that the following description of specific embodiments is only for the purpose of illustrating an example of the invention and is not intended to limit the scope of the invention in any way. Descriptions of well-known elements and well-known processing techniques are omitted so as to not unnecessarily obscure the embodiments. In this document, the term "or" is used to mean a non-exclusive "or," unless otherwise indicated, "a or B" includes "a but not B," B but not a, "and" a and B.
Example 1
Fig. 1 is a schematic block diagram showing a system for charge and discharge control of a battery pack according to embodiment 1 of the present invention.
As shown in fig. 1, a system for controlling charge and discharge of a battery pack according to embodiment 1 of the present invention includes: a Battery Management Unit (BMU) 101, a plurality of battery modules B1, B2, B3, B4, B5 constituting a battery pack, and a plurality of battery charge/discharge control units (BCU) 102, 103, 104, 105.
The battery management unit 101 may control the power or current of charge and discharge of the entire battery pack. In addition, the battery management unit 101 may also convert alternating current or direct current electric energy into electric energy for charging and discharging the entire battery pack.
The battery charge/discharge control unit 102 is connected in series with the battery module B1, and controls charge/discharge of the battery module B1 by adjusting the current passing through the battery module B1.
The battery charge/discharge control unit 103 is connected in series with the battery module B2, and controls charge/discharge of the battery module B2 by adjusting the current passing through the battery module B2.
The battery charge/discharge control unit 104 is connected in parallel with the battery module B3, and controls charge/discharge of the battery module B3 by adjusting the terminal voltage of the battery module B3.
The battery charge/discharge control unit 105 is connected in parallel with the battery module B4, and controls charge/discharge of the battery module B4 by adjusting the terminal voltage of the battery module B3.
The battery module B5 is a battery module that is not controlled by any BCU, that is, a battery module that does not perform charge-discharge control.
The arrangement of the units or modules of fig. 1 is merely for explaining the invention, and the invention is not limited thereto, but may be any arrangement different from that of fig. 1. For example, in one deployment, the battery charge-discharge control unit 102 and the battery module B1 may not exist. In another deployment, the battery charge and discharge control unit 105 and the battery module B4 may not exist. The connection relation between the battery charge/discharge control unit and the battery module for charge/discharge control may be arbitrarily changed, that is, may be either parallel or serial. In addition, the number of battery management units, battery charge/discharge control units, and battery modules may be arbitrarily set, and is not limited to the number shown in fig. 1. In addition, the number of battery modules that are not controlled by any BCU may also be zero, i.e., there are no battery modules that are not controlled by any BCU.
It is noted that in either arrangement, one battery module controlled by the same battery charge-discharge control unit is constituted by one or more battery cells. In the case where the battery module is composed of only one battery cell, the battery module is identical to the battery cell (single cell).
Fig. 2 is a flowchart illustrating a method of charge and discharge control of a battery pack according to the present invention.
As shown in fig. 2, in step 201, status information of each battery module including power, terminal voltage, current, and temperature of each battery module is acquired. If the battery module is formed of one battery cell (or the battery module has only one set of sensors for temperature, power, current and terminal voltage), the charge and discharge states of the battery cell are the states of the battery module. If the battery module is composed of a plurality of battery cells, an average value of voltage and current, and an average value of temperature calculated according to a circuit series-parallel rule may be used as the charge-discharge state of the battery module in one case, and the charge-discharge state of the battery module is: the average value of the voltage and the current calculated according to the circuit series-parallel rule and the highest temperature of the battery cells included in the battery module.
In step 202, it is determined whether the charge and discharge of the battery pack have ended. For example, if the charge-discharge current of the battery pack has been kept at zero for a sufficiently long time, it is determined that the charge-discharge of the battery pack has ended, otherwise, it is determined that it has not ended.
If it is determined in step 202 that the charge and discharge of the battery pack have ended, the entire flow is ended.
If it is determined at step 202 that the charge and discharge of the battery pack are not finished, at step 203, charge and discharge commands for the respective battery charge and discharge control units are calculated using the optimal control parameter values and the temperatures of the respective battery modules (including the temperatures of the battery modules that do not perform charge and discharge control). Here, it should be noted that the charge and discharge commands may be different for different BCUs based on different principles, and at different times. The calculation of the charge-discharge command of the present invention is as described later with reference to fig. 4.
In step 204, the charge and discharge command is output to the corresponding battery charge and discharge control unit to control the charge and discharge of the corresponding battery module.
Next, in step 205, the accumulated time from the end of the last degradation calculation period tp to the current time is compared with the size of the degradation calculation period tp. If the accumulated time is greater than or equal to the degradation calculation period tp, step 206 is entered to enter the optimal control parameter value update process. Otherwise, return to step 201. Here, the degradation calculation period tp is an integer multiple of the period value of the sampling period in which the real-time charge-discharge state of the battery module is sampled.
When the optimum control parameter value updating process is entered, first, in step 206, the degradation states of the respective battery modules to be subjected to charge-discharge control are calculated.
As an example, the degradation state of the battery module may be obtained by calculating the internal resistance of the battery module. The calculation formula is:
Ri(t)＝u(t)/i(t)
where Ri (t) is the internal resistance of the battery module i at time t, u (t) is the terminal voltage of the battery module at the current time, and i (t) is the charge-discharge current of the battery module at the current time.
Because one internal resistance Ri can be calculated at each time in a short time range, a fitting algorithm may be used in some cases (not necessarily) to calculate the average internal resistance of a certain battery module for a short period of time, and the internal resistance may be taken as the internal resistance for that period of time.
For example, as shown in fig. 3, point 209 is the (u (tt), i (tt)) coordinates of a certain battery module at any time tt within a short period of time including time t. The line 210 is a linear function fitted to the points 209, and the slope of the line 210 may be used to characterize the average internal resistance of the battery module at that time t.
If the rated internal resistance of the battery module is known, the initial internal resistance of the battery module may be calculated using a calculation formula of the series or parallel resistance. Specifically, if connected in series, then: battery module internal resistance = sum of all battery cell internal resistances; if connected in parallel, then: 1/battery module internal resistance= (1/certain battery cell internal resistance). If the rated internal resistance of the battery module is not known, the internal resistance value calculated according to the above-described method or the method shown in fig. 3 may be taken as the initial internal resistance of the battery module at time 0 or for a short period of time from time 0.
The degradation state of the battery module at time t may be obtained by dividing the internal resistance of the battery module at time t by the initial internal resistance of the battery module.
The description is continued with reference to fig. 2. In step 207, a set value of the lifetime of the battery module is obtained. The set value of the lifetime of the battery module generally represents the desired degradation rate or lifetime of each battery module. If this information does not exist, the default lifetime of each battery module may be set to be equal to the degradation speed or lifetime of each battery module.
Then, in step 208, the optimal control parameter value required for calculation of the charge/discharge command in step 203 is calculated for the temperature difference between the temperature of each battery module and the temperature of the battery module as a reference, using the lifetime set value of the battery module and the battery degradation state. This will be described later with reference to fig. 6.
In embodiment 1 of the present invention, the battery module B5 that does not perform charge/discharge control may be selected as the above-described battery module as a reference.
Fig. 4 is a schematic block diagram illustrating charge-discharge dynamic charge-discharge control logic according to the present invention.
As shown in fig. 4, first, an optimum control parameter value 401 is input. The optimal control parameter value 401 may be calculated according to the process shown in fig. 6. The optimal control parameter values include: optimal temperature difference for each battery module.
The controller 402 calculates a charge/discharge control command of the battery charge/discharge control unit 403, and the battery charge/discharge control unit 403 controls charge/discharge of the battery module B1 according to the calculated charge/discharge control command. Similarly, the controllers 405, 408, and 411 calculate charge and discharge control commands of the battery charge and discharge control units 406, 409, and 412. The battery charge and discharge control units 406, 409, and 412 control charge and discharge of the battery modules B2, B3, and B4 according to the calculated corresponding charge and discharge control commands.
In fig. 4, 415, 416, 417, 418, and 419 represent the temperatures of the respective battery modules that are currently actually measured.
420 is a process of calculating the input amounts of the respective controllers. For example, for the controller 402, the calculation formula is:
input amount=optimum control parameter value+tb1 to Tb5
Wherein the optimal control parameter value is an optimal temperature difference between the temperature of the battery module B1 and the temperature of the battery module B5, and Tb1 is a temperature measured at the present time of B1 (denoted by 415). Tb5 is the temperature measured by battery module B5 at the present time (denoted by 419). Here, the temperature of the battery module B5 at the present time, which does not perform charge/discharge control, is selected as the reference for comparison of the input amounts, but the present invention is not limited thereto.
Fig. 5A is a transfer function block diagram of an algorithm employed by the controller.
This FIG. 5A schematically illustrates a typical PID (pro-integrated-Derivative) controller algorithm.
In fig. 5A, kp, ki and Kd are parameters of the PID controller, given empirically.
The controller algorithm shown in fig. 5A is adapted to a battery charge-discharge control unit that directly controls battery charge-discharge power, voltage or current.
Fig. 5B is a transfer function block diagram of another algorithm employed by the controller.
This fig. 5 illustrates an algorithm in which a PID controller is connected in series with a sigmoid function 321. Kp, ki, kd are parameters of the PID controller, determined empirically.
The controller algorithm shown in fig. 5B is adapted to the battery charge-discharge control unit that adjusts the duty cycle of the battery module charge-discharge current.
It should be noted that the present invention is not limited to the PID controllers shown in fig. 5A and 5B, and other control algorithms may be applied to the controllers included in fig. 4. In addition, in addition to the sigmoid function 321, other monotonic functions having a value range of [0,1] or [ -1,1] may also be applicable.
Fig. 6 is a flowchart showing a process of updating the optimal control parameter values required for the battery dynamic charge and discharge control logic.
In step 602, the degradation states of the plurality of battery modules to be charge-discharge controlled calculated by step 206 in fig. 2 are obtained. If a battery module is formed of one battery cell (or the battery module has only one set of sensors for temperature, power, current and terminal voltage), the degradation state of the battery cell is the degradation state of the battery module. If a certain battery module is composed of a plurality of battery cells, the degradation state of the battery module is an average value of the degradation states of all the battery cells included in the battery module in one case, and the degradation state of the battery module is the worst value of the degradation states of all the battery cells included in the battery module in another case.
In step 603, a difference between the actual degradation state of each battery module obtained in step 602 and a degradation set value of each battery module set in advance is calculated. Here, for example, the degradation set value is given by the outside, and if there is no outside given information, it is assumed that all the battery modules have the same degradation set value, which value=the internal resistance at the time of battery discard/the initial internal resistance of the battery.
In step 604, the actual degradation state of each battery module obtained in step 603 is output to an external system.
In step 605, the difference value calculated in step 603 for each battery module is compared with a preset threshold value. A comparison is made. And if the comparison result is that the calculated difference value of each battery module is smaller than or equal to the threshold value, the current optimal control parameter value is kept unchanged. Proceed to step 607. Here, for example, the threshold value may be empirically determined, and the smaller the threshold value, the better the overall control accuracy, and the larger the threshold value, the worse the overall control accuracy.
If the comparison results in the calculated difference for at least one of the plurality of battery modules being greater than the predetermined threshold, then step 606 is entered. At step 606, new optimal control parameter values are adjusted and calculated, and step 607 is entered. The process of calculating the new optimal control parameter value will be described in detail later with reference to fig. 7.
In step 607, the optimal control parameter values calculated in step 606 may be output to a PID controller to further generate charge and discharge commands for the respective battery modules.
Fig. 7 is a schematic diagram for explaining a process of calculating optimal control parameter values required for the battery dynamic charge-discharge control logic.
As shown in fig. 7, the optimal calculation units 701, 702, and 703 are units that calculate optimal control parameter values at different times tb1, tb2, and tb3, respectively.
704. 707 and 710 denote result information of the previous calculation of the optimal control parameter value, including the result of the optimal calculation at the time instant and historically, the result including the optimal control parameter value and intermediate state information in the optimal calculation process.
705. 708 and 711 represent the real-time degradation state of the battery module at different times, and previous history values. Here, for example, the history value of the real-time degradation state refers to the degradation state of a certain battery module at a previous history time, that is: internal resistance at that time/initial internal resistance.
706. 709 and 712 represent the output of the calculated new optimal control parameter values. For example, the optimal control parameter value includes an optimal temperature difference between the temperature of each battery module and the temperature of the battery module as a reference.
The calculation methods included in the optimal calculation units 701, 702, and 703 are based on an optimization algorithm, and may be, for example, one of methods including a plurality of iterative calculations such as a genetic algorithm, an ant colony algorithm, a particle swarm optimization algorithm, and the like.
The input quantity of the optimal algorithm is as follows: the degradation state of the plurality of battery modules to be charge-discharge controlled, the lifetime setting value set for the plurality of battery modules to be charge-discharge controlled, and the historical iteration state of the optimal algorithm that calculated the optimal control parameter value last time. The optimizable independent variable is an optimal temperature difference between the temperatures of the plurality of battery modules to be charge-discharge controlled and the temperature of the battery module as a reference. The objective function of the optimization algorithm is the sum of differences between actual degradation states of a plurality of battery modules to be charge-discharge controlled at the same time and lifetime set values. Based on this information, the optimization algorithm will automatically iteratively update the optimal temperature differences for each battery module.
The optimal algorithm includes a plurality of iterations, and a degradation calculation unit at a certain moment, such as an optimal calculation unit 701 (or 702 or 703), includes one of the iterations of the optimal algorithm. The state information of the optimization calculation represented by 704 or 707 or 710 is all the information contained in the state of the previous iteration of the optimization algorithm. Each iterative calculation updates the value of the optimal temperature difference for each battery module.
Another alternative calculation method included in the optimal calculation unit 701 or 702 or 703 is: if the difference between the degradation state of a certain battery module and the set or default lifetime setting, labeled ds, is greater than the average of the differences between the degradation state of all battery modules and the set or default lifetime setting, the optimal temperature difference for that battery module is increased in proportion to ds, whereas the optimal temperature difference is decreased in proportion to ds. The changed optimal temperature difference is the optimal control parameter value of the battery module at the moment.
In addition, the possible difference may be defined by the inverse of the above values, and the calculation methods included in the optimal calculation unit 701, 702 or 703 will be: if the difference between the degradation state of a certain battery module and the set or default lifetime setting, labeled ds1, is greater than the average of the differences between the degradation states of all battery modules and the set or default lifetime setting, the optimal temperature difference for that battery module is reduced in proportion to ds1, and conversely the optimal temperature difference is increased in proportion to ds 1. The changed optimal temperature difference is the optimal control parameter value of the battery module at the moment.
According to embodiment 1 of the present invention, a device and a strategy for charging and discharging a battery pack including a plurality of battery cells can be calculated based on only state information of charging and discharging of the battery, so that the overall degradation of the battery pack is improved, and the degradation state of each battery module can be calculated.
Example 2
In embodiment 1 described above, a case is shown in which the battery module B5 that does not perform charge/discharge control is included in the system that performs charge/discharge control of the battery pack, and the battery module B5 is set as the reference battery module. However, the present invention is also applicable to a system in which there is no battery module B5 for which charge/discharge control is not performed.
Fig. 8 is a schematic block diagram showing a system for charge and discharge control of a battery pack according to embodiment 2 of the present invention.
The difference between the system arrangement of embodiment 2 shown in fig. 8 and the system arrangement of embodiment 1 shown in fig. 1 is only that there is no battery module B5 in the system arrangement of fig. 8 that is not subjected to charge-discharge control.
In this case, any one of the plurality of battery modules B1, B2, B3, B4 to be subjected to charge-discharge control may be selected as the battery module, for example, the battery module B2, as the reference.
At this time, the optimal temperature difference is set to be a temperature difference between the temperatures of the plurality of battery modules B1, B2, B3, B4 and the battery module B2 as a reference.
Except for this, other processes of the method of controlling charge and discharge of the battery pack according to embodiment 2 of the present invention are similar to those of embodiment 1 of the present invention, and thus detailed descriptions thereof are omitted.
According to embodiment 2 of the present invention, even in the case where there is no battery module for which charge/discharge control is not performed, the apparatus and strategy for charging/discharging the battery pack including the plurality of battery cells can be calculated based on the state information of charge/discharge of the battery, so that the overall degradation of the battery pack can be improved, and the degradation state of each battery module can be calculated.
In addition, it should be noted that the techniques of the present disclosure may be implemented in hardware and/or software (including firmware, microcode, etc.). Additionally, the techniques of this disclosure may take the form of a computer program product on a computer-readable medium having instructions stored thereon, the computer program product being usable by or in connection with an instruction execution system (e.g., one or more processors). In the context of this disclosure, a computer-readable medium may be any medium that can contain, store, communicate, propagate, or transport the instructions. For example, a computer-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. Specific examples of the computer readable medium include: magnetic storage devices such as magnetic tape or hard disk (HDD); optical storage devices such as compact discs (CD-ROMs); a memory, such as a Random Access Memory (RAM) or a flash memory; and/or a wired/wireless communication link.
The foregoing description of the specific embodiments will be provided to illustrate the principles of the invention and its practical application, and not to limit the invention, but to enable others skilled in the art to make various modifications and improvements without departing from the spirit and scope of the invention. Accordingly, the invention should not be limited by the above-described embodiments, but by the following claims and their equivalents.
Claims (7)
1. A method of charge and discharge control of a battery pack, the method comprising:
calculating the degradation state of each battery module according to the real-time charge and discharge state of each battery module for a plurality of battery modules to be subjected to charge and discharge control in the battery pack;
calculating a difference between a degradation state of each battery module and a degradation set value preset for each battery module;
if the difference between the degradation state of at least one of the plurality of battery modules and the degradation set value preset for that battery module is greater than a preset threshold value, calculating an optimal control parameter value for the temperature difference between the temperature of each of the plurality of battery modules and the temperature of the battery module that is the reference among the plurality of battery modules;
generating charge and discharge commands for each of the plurality of battery modules using the calculated optimal control parameter value and a temperature difference between the temperature of each of the battery modules currently actually measured and the temperature of the battery module as a reference; and
controlling charge and discharge of each of the plurality of battery modules using charge and discharge commands generated for each of the battery modules,
the optimal control parameter value is calculated based on an optimization algorithm comprising a plurality of iterative calculations,
the input amount of the optimization algorithm is the degradation state of the plurality of battery modules to be charge-discharge controlled, the lifetime set value of the plurality of battery modules to be charge-discharge controlled, the optimizable independent variable of the optimization algorithm is the optimal temperature difference between the temperature of the plurality of battery modules to be charge-discharge controlled and the temperature of the battery module as a reference, the objective function of the optimization algorithm is the sum of the differences between the degradation state of the plurality of battery modules to be charge-discharge controlled and the lifetime set value,
the multiple iterative calculations are performed at a degradation calculation period, which is an integer multiple of a period value of a sampling period in which the real-time charge and discharge states of the battery module are sampled,
each iterative calculation is based on the real-time charge-discharge state of each battery module, and the historical state of the previous iterative calculation.
2. The method of claim 1, wherein the step of determining the position of the substrate comprises,
the battery module serving as a reference of the plurality of battery modules is a battery module that does not perform charge-discharge control.
3. The method of claim 1, wherein the step of determining the position of the substrate comprises,
the battery module serving as a reference of the plurality of battery modules is any one of the plurality of battery modules to be subjected to charge-discharge control.
4. The method of claim 1, wherein the step of determining the position of the substrate comprises,
the degradation state of each battery module is obtained by calculating the internal resistance of the battery module using the current and voltage of the battery module.
5. The method of claim 4, wherein the step of determining the position of the first electrode is performed,
in the case where the battery module includes a plurality of battery cells, the current and voltage of the battery module are average or maximum values of the current and voltage of each battery cell included in the battery module.
6. The method of claim 1, wherein the step of determining the position of the substrate comprises,
in the case where the battery module includes a plurality of battery cells, the temperature of the battery module is an average value or a maximum value of the temperatures of the battery cells included in the battery module.
7. An apparatus for controlling charge and discharge of a battery pack, the apparatus comprising:
a unit that calculates a degradation state of each battery module from a real-time charge/discharge state of each battery module for a plurality of battery modules to be charge/discharge controlled in the battery pack;
a unit that calculates a difference between a degradation state of each battery module and a degradation set value preset for each battery module;
a means for calculating an optimal control parameter value for a temperature difference between a temperature of each of the plurality of battery modules and a temperature of a battery module serving as a reference among the plurality of battery modules, when a difference between a degradation state of at least one of the plurality of battery modules and a degradation set value preset for the battery module is greater than a preset threshold;
a unit that generates charge/discharge commands for each of the plurality of battery modules using the calculated optimal control parameter value and a temperature difference between the temperature of each of the battery modules currently actually measured and the temperature of the battery module as a reference; and
a unit that controls charge and discharge of each of the plurality of battery modules using a charge and discharge command generated for each of the plurality of battery modules,
the optimal control parameter value is calculated based on an optimization algorithm comprising a plurality of iterative calculations,
the input amount of the optimization algorithm is the degradation state of the plurality of battery modules to be charge-discharge controlled, the lifetime set value of the plurality of battery modules to be charge-discharge controlled, the optimizable independent variable of the optimization algorithm is the optimal temperature difference between the temperature of the plurality of battery modules to be charge-discharge controlled and the temperature of the battery module as a reference, the objective function of the optimization algorithm is the sum of the differences between the degradation state of the plurality of battery modules to be charge-discharge controlled and the lifetime set value,
the multiple iterative calculations are performed at a degradation calculation period, which is an integer multiple of a period value of a sampling period in which the real-time charge and discharge states of the battery module are sampled,
each iterative calculation is based on the real-time charge-discharge state of each battery module, and the historical state of the previous iterative calculation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810389635.3A CN110416646B (en) | 2018-04-26 | 2018-04-26 | Method and device for controlling charge and discharge of battery pack |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810389635.3A CN110416646B (en) | 2018-04-26 | 2018-04-26 | Method and device for controlling charge and discharge of battery pack |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110416646A CN110416646A (en) | 2019-11-05 |
| CN110416646B true CN110416646B (en) | 2023-05-02 |
Family
ID=68346080
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810389635.3A Active CN110416646B (en) | 2018-04-26 | 2018-04-26 | Method and device for controlling charge and discharge of battery pack |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110416646B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112467851B (en) * | 2020-12-11 | 2023-04-21 | 吉林大学 | Balanced control method for lithium iron phosphate battery pack |
| CN114243833A (en) * | 2021-12-16 | 2022-03-25 | 湖北亿纬动力有限公司 | Battery system control method and battery system |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4042917B1 (en) * | 2007-04-23 | 2008-02-06 | 株式会社パワーシステム | Capacitor power supply abnormality determination method and abnormality determination apparatus |
| JP5679738B2 (en) * | 2010-08-26 | 2015-03-04 | 株式会社日立製作所 | Battery control device and vehicle system equipped with this battery control device |
| JP6664872B2 (en) * | 2014-10-28 | 2020-03-13 | 株式会社Gbs | Charging device, charging program, charging method |
| CN104459552B (en) * | 2014-11-28 | 2017-10-17 | 上海交通大学 | The method for assessing influence of the charging behavior to batteries of electric automobile health status |
-
2018
- 2018-04-26 CN CN201810389635.3A patent/CN110416646B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN110416646A (en) | 2019-11-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20190196427A1 (en) | Controlling a Dispatch Operation of an Energy Storage System | |
| RU2684416C2 (en) | Loads scheduling in multi-battery devices | |
| US20140361732A1 (en) | Storage battery control device, storage battery control method, program, power storage system and power supply system | |
| CN107196371B (en) | Battery charging method, device, equipment and storage medium | |
| KR102574083B1 (en) | Apparatus and method for managing battery | |
| KR102516362B1 (en) | Method and apparatus for battery charging | |
| JP2021506221A (en) | A non-linear voltammetry-based method for charging a battery, and a fast charging system that implements this method. | |
| KR101866020B1 (en) | Method for controlling start of fuel cell vehicle | |
| US20140097787A1 (en) | Active battery management system for a battery pack | |
| CN110416646B (en) | Method and device for controlling charge and discharge of battery pack | |
| KR20150137675A (en) | Method and apparatus for cell balancing of battery management system | |
| CN110635187A (en) | Lithium battery charging method considering aging | |
| CN113015918A (en) | Method for determining state of health of secondary battery and battery management system | |
| CN112909354B (en) | Battery module balancing method in battery circulation, electronic device and storage medium | |
| JP5482809B2 (en) | Equalization equipment | |
| CN110492185B (en) | Lithium battery pack equalization method and system | |
| CN113195291A (en) | Improved method for controlling an energy storage system | |
| JP5760877B2 (en) | Battery control device | |
| US9142984B2 (en) | Method of searching for full charge capacity of stacked rechargeable battery cells in rechargeable battery pack and battery management system made of the same | |
| US9431846B2 (en) | Systems and methods for controlling battery charging | |
| US20230148201A1 (en) | Method and system for supplying power to device, and related device | |
| WO2023169311A1 (en) | Battery power processing method and apparatus, battery management system, and battery | |
| CN117134450A (en) | SOC balance control method for parallel battery packs and related equipment | |
| WO2022189454A1 (en) | Method and device for controlling a charging signal for charging a rechargeable battery cell or battery | |
| CN114189013A (en) | Charging device, charging method and computer readable storage medium |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |