Energy storage battery equalization control method and device and energy storage system

Abstract

The application relates to a storage battery equalization control method and device and a storage system. The storage battery equalization control method applied to the storage system comprises the following steps: acquiring an equalization priority index corresponding to each of a plurality of candidate storage batteries satisfying an equalization control condition in the storage system, wherein the equalization priority index represents an equalization priority of the candidate storage battery after being affected by operation risk characteristic information; selecting a target storage battery participating in equalization control from the plurality of candidate storage batteries for the first time according to all the equalization priority indexes; updating all the equalization priority indexes after completing equalization control on the target storage battery, and iteratively selecting the target storage battery participating in equalization control based on all the updated equalization priority indexes until equalization control is completed on all the candidate storage batteries. The method improves the equalization control effect of the storage battery.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage, in particular to an energy storage battery equalization control method and device and an energy storage system. BACKGROUND

[0002] With the continuous development of science and technology, energy storage systems have been widely used in many fields such as power systems, new energy power generation and transportation due to their high energy utilization efficiency, high reliability and strong sustainability. In order to ensure that the energy storage system operates stably, efficiently and safely, it is necessary to control the equalization of energy storage batteries.

[0003] At present, the equalization control of energy storage batteries is usually realized by fixed parameter setting, such as equalization control depending on voltage difference, pure time-driven equalization control and equalization control based on static SOC (State of Charge) threshold, etc. However, since the external operating conditions of the energy storage system are in dynamic change, the pre-set energy storage battery equalization control strategy cannot match the actual equalization control needs of the energy storage battery, so the current effect of equalization control of energy storage batteries is poor. SUMMARY

[0004] Therefore, it is necessary to provide an energy storage battery equalization control method, device and energy storage system for improving the effect of equalization control of energy storage batteries.

[0005] In a first aspect, the present application provides an energy storage battery equalization control method applied to an energy storage system, comprising:

[0006] obtaining an equalization priority index corresponding to each of a plurality of candidate energy storage batteries in the energy storage system that meet equalization control conditions, wherein the equalization priority index represents the equalization priority of the candidate energy storage battery after being affected by operating risk characteristic information, and the operating risk characteristic information includes at least one of voltage deviation risk information, capacity health risk information, operating state risk information and thermal correlation risk information;

[0007] selecting a target energy storage battery participating in equalization control from the plurality of candidate energy storage batteries for the first time according to all equalization priority indexes;

[0008] After completing the equalization control of the target energy storage battery, updating all equalization priority indexes, and iteratively selecting a target energy storage battery participating in equalization control based on all updated equalization priority indexes until the equalization control of all candidate energy storage batteries is completed.

[0009] In one of the embodiments, the obtaining of the equalization priority index of each candidate energy storage battery satisfying the equalization control condition in the energy storage system comprises:

[0010] detecting, according to the battery voltage of the energy storage system, the candidate energy storage batteries satisfying the equalization control condition in the energy storage system;

[0011] determining the operation risk characteristic value and the corresponding characteristic value weight of each candidate energy storage battery after being affected by the operation risk characteristic information, wherein the operation risk characteristic value comprises at least one of the first operation risk characteristic value after being affected by the voltage deviation risk information, the second operation risk characteristic value after being affected by the capacity health risk information, the third operation risk characteristic value after being affected by the operation state risk information, and the fourth operation risk characteristic value after being affected by the thermal correlation risk information, and the characteristic value weight comprises at least one of the first characteristic value weight corresponding to the first operation risk characteristic value, the second characteristic value weight corresponding to the second operation risk characteristic value, the third characteristic value weight corresponding to the third operation risk characteristic value, and the fourth characteristic value weight corresponding to the fourth operation risk characteristic value;

[0012] obtaining the equalization priority index of each candidate energy storage battery by fusing the operation risk characteristic value and the corresponding characteristic value weight of each candidate energy storage battery.

[0013] In one of the embodiments, the detecting of the candidate energy storage batteries satisfying the equalization control condition in the energy storage system according to the battery voltage of the energy storage system comprises:

[0014] if it is detected that the battery voltage is abnormal, performing voltage equalization control on all energy storage batteries of the energy storage system, and selecting candidate energy storage batteries satisfying the equalization control condition from all energy storage batteries after completing the voltage equalization control;

[0015] if it is detected that the battery voltage is not abnormal, regarding all energy storage batteries as candidate energy storage batteries satisfying the equalization control condition.

[0016] In one of the embodiments, the determining of the operation risk characteristic value and the corresponding characteristic value weight of each candidate energy storage battery after being affected by the operation risk characteristic information comprises:

[0017] obtaining the first voltage characteristic value of each candidate energy storage battery and the second voltage characteristic value of the battery group to which each candidate energy storage battery belongs;

[0018] determining the voltage deviation characteristic value of each candidate energy storage battery according to the first voltage characteristic value and the second voltage characteristic value.

[0019] fusing the equalization control voltage difference threshold value, the equalization stop voltage difference threshold value and the voltage deviation characteristic value of each candidate energy storage battery, to obtain the first operation risk characteristic value;

[0020] determining a voltage change characteristic value of each candidate energy storage battery;

[0021] correcting a first basic characteristic value weight of the first operation risk characteristic value according to the voltage change characteristic value, to obtain the first characteristic value weight.

[0022] In one of the embodiments, the determination of the operation risk characteristic value and the corresponding characteristic value weight of each candidate energy storage battery after being affected by the operation risk characteristic information includes:

[0023] obtaining a first state of charge characteristic value of each candidate energy storage battery and a second state of charge characteristic value of a battery pack to which each candidate energy storage battery belongs;

[0024] determining a state of charge deviation characteristic value of each candidate energy storage battery according to the first state of charge characteristic value and the second state of charge characteristic value;

[0025] fusing the equalization control state of charge difference threshold value, the equalization stop state of charge difference threshold value and the state of charge deviation characteristic value of each candidate energy storage battery, to obtain the second operation risk characteristic value;

[0026] determining a state of charge difference characteristic value, a first characteristic value under an ambient temperature and a second characteristic value under an operation stage of each candidate energy storage battery;

[0027] querying the state of charge confidence of each candidate energy storage battery according to a state of charge identifier of each candidate energy storage battery, wherein the state of charge identifier is used to distinguish and identify the category of the estimated state of charge of the candidate energy storage battery;

[0028] correcting a second basic characteristic value weight of the second operation risk characteristic value according to the state of charge difference characteristic value, the first characteristic value, the second characteristic value and the state of charge confidence, to obtain the second characteristic value weight.

[0029] In one of the embodiments, the determination of the state of charge difference characteristic value, the first characteristic value under the ambient temperature and the second characteristic value under the operation stage of each candidate energy storage battery includes:

[0030] obtaining a state of charge difference value of each candidate energy storage battery;

[0031] normalizing the state-of-charge difference value to obtain the state-of-charge difference feature value;

[0032] According to the ambient temperature value of each candidate energy storage battery, the first feature value is obtained by querying;

[0033] According to the running phase identifier of the energy storage system, the second feature value is obtained by querying.

[0034] In one embodiment, the determination of the running risk feature value and the corresponding feature value weight of each candidate energy storage battery after being affected by the running risk feature information includes:

[0035] According to the state-of-charge identifier of each candidate energy storage battery, the third running risk feature value is obtained by querying;

[0036] According to the state-of-charge identifier, the state-of-charge confidence of each candidate energy storage battery is obtained by querying;

[0037] According to the state-of-charge confidence, the third basis feature value weight of the third running risk feature value is corrected to obtain the third feature value weight.

[0038] In one embodiment, the determination of the running risk feature value and the corresponding feature value weight of each candidate energy storage battery after being affected by the running risk feature information includes;

[0039] Obtain the real-time health degree, temperature deviation value and actual temperature value of each candidate energy storage battery;

[0040] By fusing the real-time health degree, the temperature deviation value and the actual temperature value, the fourth running risk feature value is obtained;

[0041] According to the real-time health degree, the fourth basis feature value weight of the fourth running risk feature value is corrected to obtain the fourth feature value weight.

[0042] In one embodiment, the first feature value weight is , the second feature value weight is , the third feature value weight is , and the fourth feature value weight is , wherein , and each satisfy: , , , , , and satisfy: , .

[0043] In one of the embodiments, satisfies: .

[0044] In one of the embodiments, after the equalization control for the target energy storage battery is completed, the all equalization priority indicators are updated, and based on the all updated equalization priority indicators, the target energy storage battery participating in the equalization control is iteratively selected until the equalization control for all candidate energy storage batteries is completed, the energy storage battery equalization control method further comprises:

[0045] obtaining an associated characteristic value between the voltage and the state of charge of the target energy storage battery;

[0046] in the case where it is detected that the associated characteristic value is greater than or equal to a preset associated characteristic value threshold, performing voltage equalization control and capacity equalization control on the target energy storage battery;

[0047] in the case where it is detected that the associated characteristic value is less than the preset associated characteristic value threshold, performing capacity equalization control on the target energy storage battery.

[0048] In one of the embodiments, the energy storage battery equalization control method further comprises:

[0049] in the process of performing capacity equalization control on the target energy storage battery, obtaining a real-time state of charge value of the target energy storage battery and a state of charge reference value of the energy storage system;

[0050] determining a state of charge deviation value of the target energy storage battery according to the real-time state of charge value and the state of charge reference value;

[0051] in the case where it is detected that the state of charge deviation value is less than or equal to a preset state of charge deviation value threshold, stopping capacity equalization control on the target energy storage battery.

[0052] In a second aspect, the present application further provides an energy storage battery equalization control method device, applied to an energy storage system, comprising:

[0053] an obtaining module, configured to obtain an equalization priority indicator corresponding to each of a plurality of candidate energy storage batteries in the energy storage system that satisfy an equalization control condition, wherein the equalization priority indicator represents an equalization priority of the candidate energy storage battery after being affected by operation risk characteristic information, and the operation risk characteristic information includes at least one of voltage deviation risk information, capacity health risk information, operation state risk information and thermal correlation risk information;

[0054] The selecting module is configured to select, according to all the equalization priority indexes, a target energy storage battery from the plurality of candidate energy storage batteries for participating in equalization control for the first time;

[0055] The equalization control module is configured to update the all equalization priority indexes after completing the equalization control on the target energy storage battery, and iteratively select a target energy storage battery for participating in equalization control based on all the updated equalization priority indexes until the equalization control on all the candidate energy storage batteries is completed.

[0056] In a third aspect, the present application further provides a storage system, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the following steps when executing the computer program:

[0057] obtaining equalization priority indexes corresponding to a plurality of candidate energy storage batteries in the storage system that meet equalization control conditions, wherein the equalization priority indexes represent equalization priorities of the candidate energy storage batteries after being affected by operation risk characteristic information, and the operation risk characteristic information comprises at least one of voltage deviation risk information, capacity health risk information, operation state risk information, and thermal correlation risk information; selecting, according to all the equalization priority indexes, a target energy storage battery from the plurality of candidate energy storage batteries for participating in equalization control for the first time; and updating the all equalization priority indexes after completing the equalization control on the target energy storage battery, and iteratively selecting a target energy storage battery for participating in equalization control based on all the updated equalization priority indexes until the equalization control on all the candidate energy storage batteries is completed.

[0058] In a fourth aspect, the present application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the following steps:

[0059] obtaining equalization priority indexes corresponding to a plurality of candidate energy storage batteries in the storage system that meet equalization control conditions, wherein the equalization priority indexes represent equalization priorities of the candidate energy storage batteries after being affected by operation risk characteristic information, and the operation risk characteristic information comprises at least one of voltage deviation risk information, capacity health risk information, operation state risk information, and thermal correlation risk information; selecting, according to all the equalization priority indexes, a target energy storage battery from the plurality of candidate energy storage batteries for participating in equalization control for the first time; and updating the all equalization priority indexes after completing the equalization control on the target energy storage battery, and iteratively selecting a target energy storage battery for participating in equalization control based on all the updated equalization priority indexes until the equalization control on all the candidate energy storage batteries is completed.

[0060] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, performs the following steps:

[0061] The system acquires equalization priority indices for each of the multiple candidate energy storage batteries that meet the equalization control conditions within the energy storage system. Each equalization priority index represents the equalization priority of a candidate energy storage battery after being affected by operational risk characteristics, which include at least one of voltage deviation risk information, capacity health risk information, operational status risk information, and thermal correlation risk information. Based on all equalization priority indices, a target energy storage battery for equalization control is initially selected from the multiple candidate energy storage batteries. After equalization control is completed for the target energy storage battery, all equalization priority indices are updated, and based on all updated equalization priority indices, the target energy storage battery for equalization control is iteratively selected until equalization control of all candidate energy storage batteries is completed.

[0062] The aforementioned energy storage battery equalization control method, device, and energy storage system first obtain equalization priority indicators for each of multiple candidate energy storage batteries that meet the equalization control conditions within the energy storage system. These equalization priority indicators characterize the equalization priority of the candidate energy storage batteries after being affected by risk characteristic information. The operational risk characteristic information includes at least one of four: voltage deviation risk information, capacity health risk information, operational status risk information, and thermal correlation risk information. Then, based on the equalization priority indicators, a target energy storage battery is initially selected from the multiple candidate energy storage batteries to participate in the equalization control. Finally, after completing the equalization control for the target energy storage battery, all equalization priority indicators are updated, and based on all updated equalization priority indicators, the target energy storage battery participating in the equalization control is iteratively selected until the equalization control of all candidate energy storage batteries is completed. Since the equalization priority indicators characterize the equalization priority of the candidate energy storage batteries after being affected by risk characteristic information, the system first obtains equalization priority indicators for each candidate energy storage battery. The equilibrium priority presented after the influence of risk characteristic information, and the target energy storage batteries selected for the first time to participate in equilibrium control based on the equilibrium priority index, can accurately assess the potential operational risks of different energy storage batteries in the energy storage system. This achieves the purpose of quantitatively assessing the execution objects of equilibrium control. Furthermore, after performing equilibrium control on the target energy storage batteries participating in equilibrium control for the first time, the target energy storage batteries participating in equilibrium control will be dynamically adjusted until all candidate energy storage batteries have completed equilibrium control. This achieves the purpose of adaptively matching the external operating conditions of the energy storage system during the equilibrium control of energy storage batteries. This overcomes the technical defect that the pre-set energy storage battery equilibrium control strategy cannot match the actual equilibrium control needs of the energy storage batteries because the external operating conditions of the energy storage system are constantly changing. Therefore, the effect of energy storage battery equilibrium control is improved. Attached Figure Description

[0063] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related art, the accompanying drawings needed to be used in the embodiments or the related art description will be briefly introduced. Obviously, the accompanying drawings in the following description only represent some embodiments of the present application, and for those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0064] Figure 1 A flowchart of the energy storage battery equalization control method in one embodiment;

[0065] Figure 2 A flowchart of the energy storage battery equalization control method in another embodiment;

[0066] Figure 3 A flowchart of the energy storage battery equalization control method in another embodiment;

[0067] Figure 4 A block diagram of the energy storage battery equalization control device in one embodiment;

[0068] Figure 5 An internal structure diagram of the terminal for monitoring and control in one embodiment of the energy storage system. DETAILED DESCRIPTION

[0069] In order to make the purposes, technical solutions and advantages of the present application more clear, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not intended to limit the present application.

[0070] Firstly, it should be understood that in the field of energy storage technology, the equalization control of energy storage batteries is one of the indispensable technical links, wherein the energy storage battery refers to a battery that can store and release electric energy when needed, which is the core energy carrier of the energy storage system to realize energy storage and flexible allocation; at present, the equalization control of energy storage batteries is usually realized by fixed parameter setting, which can specifically include equalization control depending on voltage difference, pure time driven equalization control and equalization control based on static SOC threshold, etc.; however, the above equalization control methods all have inherent defects, specifically, in the equalization control method depending on voltage difference, since the voltage difference cannot be equal to the capacity difference, if the set voltage difference threshold is taken as the quantitative basis for equalization control, the real capacity difference between the energy storage batteries which has not been eliminated will continue to deteriorate, and then the equalization control is prone to be mis-closed when it is not completed, at the same time, in the non-voltage platform area, since the voltage will fluctuate sharply with the state of charge, the equalization threshold will be frequently triggered or exceeded, leading to repeated start-stop of the equalizer, so that over-equalization is prone to occur, and when the energy storage battery with low voltage variation sensitivity is used, this equalization control method cannot be applied, for example, the voltage difference of LFP (Lithium Iron Phosphate, Lithium Iron Phosphate battery) in the voltage platform area is only 1 / 10 of that of ternary battery, and the weak voltage difference is difficult to be detected or trigger the threshold, thereby causing the scheme to lose the basis for judgment, so that the equalization control means is completely ineffective; in the pure time driven equalization control method, since the time of each equalization control is fixed, when the capacity difference is too large, the equalization will be insufficient due to insufficient transfer capacity, and when the capacity difference is too small, the cycle life of the battery will be excessively consumed; in the equalization control method based on static SOC threshold, on the one hand, after the energy storage battery enters the voltage platform period, the weak voltage difference will cause the estimation of the state of charge to lose the calibration basis, thereby causing the equalization function to fail, on the other hand, due to the change of the temperature of the energy storage battery, the determination of the state of charge will be different from the actual state of charge of the energy storage battery, which not only affects the accuracy of the equalization control, but also may inversely enlarge the inconsistency between the energy storage batteries; in summary, the essence is that the external operating conditions of the energy storage system are in dynamic change, thereby causing the equalization control of the energy storage battery to be unable to meet the actual equalization control demand of the energy storage battery, therefore, there is an urgent need for an energy storage battery equalization control method which can improve the effect of equalization control of energy storage batteries.

[0071] In one embodiment, as Figure 1As shown, a storage battery equalization control method is provided. In this embodiment, the method is applied to a storage system, which includes but is not limited to a storage battery pack, a BMS (Battery Management System), and a PCS (Power Conversion System). The storage system is provided with a storage battery equalization control device, which is used to execute the storage battery equalization control method to achieve equalization management of the storage battery in the storage system. The storage battery equalization control device includes an acquisition module, a selection module, and an equalization control module. The acquisition module is used to acquire equalization priority indicators corresponding to a plurality of candidate storage batteries in the storage system that meet equalization control conditions. The equalization priority indicators represent the equalization priority of the candidate storage batteries after being affected by operating risk characteristic information, which includes at least one of voltage deviation risk information, capacity health risk information, operating state risk information, and thermal correlation risk information. The selection module is used to select a target storage battery participating in equalization control from the plurality of candidate storage batteries based on all equalization priority indicators. The equalization control module is used to update all equalization priority indicators after completing equalization control on the target storage battery, and iteratively select a target storage battery participating in equalization control based on all updated equalization priority indicators until equalization control is completed on all candidate storage batteries. In this embodiment, the target storage battery participating in equalization control is first selected through the equalization priority indicators, so that the potential operating risks of different storage batteries in the storage system can be accurately evaluated, and the purpose of quantitatively evaluating the execution object of equalization control is achieved. Further, after equalization control is performed on the target storage battery participating in equalization control, the target storage battery participating in equalization control is dynamically adjusted until equalization control is completed on all candidate storage batteries, so that the purpose of adaptively matching the external operating conditions of the storage system during equalization control of the storage battery is achieved. Therefore, the effect of equalization control of the storage battery is improved. It can be understood that the method can also be applied to a server and a system including the storage system and the server, and is implemented through interaction between the storage system and the server. In this embodiment, the method includes the following steps 202 to 206.

[0072] In step 202, equalization priority indicators corresponding to a plurality of candidate storage batteries in the storage system that meet equalization control conditions are acquired. The equalization priority indicators represent the equalization priority of the candidate storage batteries after being affected by operating risk characteristic information, which includes at least one of voltage deviation risk information, capacity health risk information, operating state risk information, and thermal correlation risk information.

[0073] It should be noted that the current equalization control effect of the energy storage battery set by the fixed parameter setting mode is poor, mainly in the following aspects: 1) the equalization control mode cannot intelligently decide the execution order when the energy storage battery meets the voltage equalization condition (for example, high ) and the capacity equalization condition (for example, high ) at the same time, resulting in the problem of fuzzy equalization control priority between multiple energy storage batteries in the equalization control scene; 2) when multiple energy storage batteries trigger equalization control at the same time, the equalization current resource cannot be allocated through a quantitative model, resulting in local over-regulation of energy storage batteries or the situation that key energy storage batteries are not processed in the energy storage system; 3) for capacity equalization between energy storage batteries, it may be mistakenly closed due to too small pressure difference in the voltage platform area, thereby affecting the health management effect of the energy storage battery. Based on this, the embodiment sets a quantifiable equalization priority index to evaluate the priority of different energy storage batteries participating in equalization control.

[0074] It should be noted that the equalization priority index represents the equalization priority of the candidate energy storage battery after being affected by the operation risk characteristic information, and the operation risk characteristic information includes at least one of voltage deviation risk information, capacity health risk information, operation state risk information and thermal correlation risk information. The candidate energy storage battery refers to the energy storage battery in the energy storage system waiting for equalization control. It can be understood that not all energy storage batteries in the energy storage system will participate in equalization control. Only when the energy storage battery meets the equalization control condition, the energy storage battery will be a candidate energy storage battery. The equalization control condition refers to the standard for determining whether the energy storage battery needs to participate in equalization control in the energy storage system, which can specifically include voltage difference condition, state of charge difference condition, capacity difference condition, temperature difference condition and current difference condition. For example, in an implementable manner, if the state of charge, capacity change value or temperature change value of the energy storage battery is within the corresponding preset safe range, or the energy storage battery is in a fault state or a dormant state, the energy storage battery is not a candidate energy storage battery. Only when the energy storage battery meets the equalization control condition, it will be a candidate energy storage battery.

[0075] It should be noted that the operation risk characteristic information represents the risk dimension affecting the performance reliability and safety stability of the energy storage battery in the operation process of the energy storage battery. Through the operation risk characteristic information, the internal performance state of the energy storage battery in the operation process can be objectively reflected. The operation risk characteristic information includes at least one of voltage deviation risk information, capacity health risk information, operation state risk information and thermal correlation risk information. The voltage deviation risk information represents the deviation degree between the voltage of the energy storage battery and the reference voltage in the energy storage system in the operation process of the energy storage battery. Through the voltage deviation risk information, the operation risk caused by voltage deviation in the operation process of the energy storage battery can be objectively reflected. The capacity health risk information represents the difference degree between the actual capacity of the energy storage battery and the reference capacity in the energy storage system in the operation process of the energy storage battery. Through the capacity risk information, the operation risk caused by capacity health in the operation process of the energy storage battery can be objectively reflected. The operation state risk information represents the difference degree between the actual working condition of the energy storage battery and the reference working condition in the energy storage system in the operation process of the energy storage battery. Through the operation state risk information, the operation risk caused by the operation working condition in the operation process of the energy storage battery can be objectively reflected. The thermal correlation risk information represents the difference degree between the actual temperature of the energy storage battery and the reference temperature in the energy storage system in the operation process of the energy storage battery. Through the thermal correlation risk information, the operation risk caused by the thermal correlation factor in the operation process of the energy storage battery can be objectively reflected. The reference voltage, the reference capacity, the reference working condition and the reference temperature can be set in advance in the energy storage system or dynamically calibrated, for example, the reference voltage can be the real-time average voltage of all normally operating energy storage batteries in the energy storage system, the reference capacity can be the actual average voltage calibrated by the energy storage system through the charge and discharge cycle test, the reference working condition can be the conventional operation working condition of the energy storage system set in advance, and the reference temperature can be the average battery temperature in the historical operation data of the energy storage system. It can be understood that for the candidate energy storage battery, the more serious the voltage deviation, the higher the balancing priority, the higher the capacity health risk, the higher the balancing priority, the worse the operation state, the higher the balancing priority, and the higher the thermal correlation risk, the higher the balancing priority.

[0076] It should be noted that the equalization priority index of the candidate energy storage battery can be represented by a single operation risk characteristic information, or the equalization priority index of the candidate battery can be represented by multiple different operation risk characteristic information; for example, in an implementable manner, the influence degree of the battery deviation risk information, the capacity health risk information, the operation state risk information and the thermal correlation risk information on the equalization control of the energy storage battery can be set to be the same, and then the real-time operation data (real-time voltage, real-time working condition, real-time temperature and real-time capacity) of the candidate energy storage battery is collected through the voltage sensor, the current sensor, the temperature sensor and the capacity detection module, and the operation risk quantitative value corresponding to different operation risk characteristic information is calculated based on the real-time operation data and the benchmark operation data (benchmark voltage, benchmark working condition, benchmark capacity and benchmark temperature), and then the total operation risk quantitative value of the candidate energy storage battery is fused (for example, the operation risk quantitative values corresponding to each operation risk characteristic information are added), and finally the equalization priority index corresponding to the total operation risk quantitative value is queried.

[0077] As an example, step 202 includes: selecting a plurality of energy storage batteries with actual health states within a safe range as candidate energy storage batteries in the energy storage system, and extracting real-time operation data of each candidate energy storage battery, calculating a total operation risk quantitative value of each candidate energy storage battery affected by operation characteristic risk information according to the real-time operation data of each candidate energy storage battery, and querying the equalization priority index corresponding to each candidate energy storage battery according to the total operation risk quantitative value.

[0078] Step 204, according to all equalization priority indexes, first select target energy storage batteries participating in equalization control from a plurality of candidate energy storage batteries.

[0079] It should be noted that after obtaining the equalization priority index of each candidate energy storage battery, the equalization priority of all candidate energy storage batteries can be sorted based on the equalization priority index, and after the sorting is completed, the target energy storage battery first participating in the equalization control is selected from the plurality of candidate energy storage batteries, wherein the number of target energy storage batteries is less than the number of all candidate energy storage batteries, which can be one or more, and can be determined by factors such as equalization control capability of the energy storage system, operation condition demand and equalization efficiency target.

[0080] As an example, step 204 includes: sorting all candidate energy storage batteries in order from high to low according to all equalization priority indexes, and selecting a preset number of candidate energy storage batteries at the front of the sorting as target energy storage batteries first participating in the equalization control.

[0081] At step 206, after the equalization control for the target energy storage battery is completed, all equalization priority indicators are updated, and based on all updated equalization priority indicators, the target energy storage battery participating in the equalization control is iteratively selected until the equalization control for all candidate energy storage batteries is completed.

[0082] It should be noted that the energy storage system will allocate equalization resources such as current and channel to the candidate energy storage batteries for equalization control according to the equalization priorities of different candidate energy storage batteries. After the target energy storage battery participating in the equalization control for the first time completes the equalization control, the equalization priorities of the remaining candidate energy storage batteries can be updated periodically, and the target energy storage battery participating in the equalization control is iteratively selected until the equalization control for all candidate energy storage batteries is completed. For example, in an implementable manner, assuming that the plurality of candidate energy storage batteries include candidate energy storage battery x1, candidate energy storage battery x2, candidate energy storage battery x3, candidate energy storage battery x4, and candidate energy storage battery x5, wherein the equalization priority indicators corresponding to x1, x2, x3, x4, and x5 are 90, 85, 88, 84, and 82 respectively, then candidate energy storage battery x1 and candidate energy storage battery x3 can be selected as the target energy storage battery participating in the equalization control for the first time, and then after candidate energy storage battery x1 and candidate energy storage battery x3 complete the equalization control, the equalization priority indicators of candidate energy storage battery x2, candidate energy storage battery x4, and candidate energy storage battery x5 are updated, and the updated equalization priority indicators corresponding to x2, x4, and x5 are 81, 86, and 82 respectively. Then, candidate energy storage battery x4 and candidate energy storage battery x5 are selected as the target energy storage battery participating in the equalization control for the second time, and after candidate energy storage battery x4 and candidate energy storage battery x5 complete the equalization control, candidate energy storage battery x2 is finally selected as the target energy storage battery participating in the equalization control, and the equalization control for all candidate energy storage batteries is completed. It can be understood that the equalization control for the target energy storage battery can specifically include voltage equalization control and / or capacity equalization control.

[0083] As an example, step 206 includes: after the equalization control for the target energy storage battery is completed, updating the equalization priority indicators corresponding to all candidate energy storage batteries except the target energy storage battery, obtaining all updated equalization priority indicators, and based on all updated equalization priority indicators, iteratively selecting the target energy storage battery participating in the equalization control until the equalization control for all candidate energy storage batteries is completed.

[0084] It can be understood that, since the equalization priority index is a quantitative basis for directly evaluating the priority of the energy storage battery participating in the equalization control, the priority of the energy storage battery participating in the equalization control is not affected by the type of the energy storage battery in the process of equalization control of the energy storage battery, for example, whether it is a ternary battery or LFP, the above-mentioned equalization control mode can be used to realize the equalization control of the energy storage battery, at the same time, the equalization priority index can also intelligently decide the execution timing of different candidate energy storage batteries participating in the equalization control, in addition, since it does not rely on the pressure difference for single-dimensional judgment, it will not appear in the voltage platform area due to the small pressure difference. The situation of being mistakenly closed, therefore, in summary, the effect of equalization control of the energy storage battery can be improved from multiple aspects.

[0085] The above-mentioned energy storage battery equalization control method, first, obtains the equalization priority index corresponding to each of the plurality of candidate energy storage batteries in the energy storage system that meets the equalization control condition, wherein the equalization priority index represents the equalization priority of the candidate energy storage battery affected by the risk characteristic information, and the operation risk characteristic information includes at least one of the voltage deviation risk information, the capacity health risk information, the operation state risk information and the thermal correlation risk information; then, according to the equalization priority index, the target energy storage battery participating in the equalization control is first selected from the plurality of candidate energy storage batteries; finally, after completing the equalization control on the target energy storage battery, all the equalization priority indexes are updated, and the target energy storage battery participating in the equalization control is iteratively selected based on all the updated equalization priority indexes, until the equalization control of all the candidate energy storage batteries is completed; since the equalization priority index represents the equalization priority of the candidate energy storage battery affected by the risk characteristic information, and the target energy storage battery participating in the equalization control is first selected depending on the equalization priority index, the potential operation risk of different energy storage batteries in the energy storage system can be accurately evaluated, thereby realizing the purpose of quantitatively evaluating the execution object of the equalization control, further, after the target energy storage battery participating in the equalization control is first executed, the target energy storage battery participating in the equalization control is dynamically adjusted until all the candidate energy storage batteries complete the equalization control, thereby realizing the purpose of adaptively matching the external operation condition of the energy storage system in the process of equalization control of the energy storage battery, thereby overcoming the technical defect that the pre-set energy storage battery equalization control strategy cannot match the actual equalization control demand of the energy storage battery due to the dynamic change of the external operation condition of the energy storage system, therefore, the effect of equalization control of the energy storage battery is improved.

[0086] In one embodiment, as shown in Figure 2 the equalization priority index corresponding to each of the plurality of candidate energy storage batteries in the energy storage system that meets the equalization control condition includes steps 302 to 306:

[0087] At step 302, a plurality of candidate energy storage cells satisfying the equalization control condition in the energy storage system is detected according to the battery voltage of the energy storage system.

[0088] It should be noted that in the actual application of the energy storage system, the detection efficiency and detection condition of the equalization control condition are considered, and whether the energy storage cell in the energy storage system satisfies the equalization control condition is detected by the battery voltage of the energy storage system. The battery voltage can be the single cell voltage of the energy storage cell, the voltage difference of the battery pack to which the energy storage cell belongs, or the average voltage of the battery pack to which the energy storage cell belongs, etc. The battery voltage can be obtained by a voltage sensor or after collection.

[0089] As an example, step 302 includes obtaining the single cell voltage of all energy storage cells in the energy storage system, and determining the energy storage cell whose single cell voltage is greater than the preset single cell voltage threshold as the candidate energy storage cell satisfying the equalization control condition.

[0090] As another example, step 302 includes obtaining the group voltage difference value of the battery pack to which each energy storage cell belongs in the energy storage system, and determining the energy storage cell whose group voltage difference value is greater than the preset group voltage difference threshold as the candidate energy storage cell satisfying the equalization control condition.

[0091] At step 304, the running risk characteristic value of each candidate energy storage cell after being affected by the running risk characteristic information and the corresponding characteristic value weight are determined, wherein the running risk characteristic value includes at least one of the first running risk characteristic value after being affected by the voltage deviation risk information, the second running risk characteristic value after being affected by the capacity health risk information, the third running risk characteristic value after being affected by the running state risk information, and the fourth running risk characteristic value after being affected by the thermal correlation risk information, and the characteristic value weight includes at least one of the first characteristic value weight corresponding to the first running risk characteristic value, the second characteristic value weight corresponding to the second running risk characteristic value, the third characteristic value weight corresponding to the third running risk characteristic value, and the fourth characteristic value weight corresponding to the fourth running risk characteristic value.

[0092] It should be noted that, since the influence degree of different operation risk characteristic information on the energy storage battery usually exists differences, and the external conditions of the energy storage system are in dynamic changes, and then the operation risk characteristic value and the characteristic value weight determined in the real-time operation process can be used to calculate the real-time balance priority index of the candidate energy storage system, wherein the operation risk characteristic value refers to the numerical value quantitatively obtained to measure the influence degree of the operation risk characteristic information on the energy storage battery, and the characteristic value weight represents the importance degree of the operation risk characteristic value to the operation risk of the energy storage battery; it can be understood that there is a mapping relationship between the characteristic value weight and the operation risk characteristic value, and then the corresponding characteristic value weight can be queried after the operation risk characteristic value is determined, and the operation risk characteristic value can be mapped from the data deviation value between the real-time operation data and the benchmark operation data of the energy storage battery.

[0093] As an example, step 304 includes: obtaining a voltage data deviation value of each candidate energy storage battery according to real-time voltage data and benchmark voltage data of each candidate energy storage battery, and mapping the voltage data deviation value to a first operation risk characteristic value, querying a corresponding first characteristic value weight according to the first operation risk characteristic value, obtaining a capacity data deviation value of each candidate energy storage battery according to real-time capacity data and benchmark capacity data of each candidate energy storage battery, and mapping the capacity data deviation value to a second operation risk characteristic value, querying a corresponding second characteristic value weight according to the second operation risk characteristic value, obtaining a working condition data deviation value of each candidate energy storage battery according to real-time working condition data and benchmark working condition data of each candidate energy storage battery, and mapping the working condition data deviation value to a third operation risk characteristic value, querying a corresponding third characteristic value weight according to the third operation risk characteristic value, and obtaining a temperature data deviation value of each candidate energy storage battery according to real-time temperature data and benchmark temperature data of each candidate energy storage battery, and mapping the temperature data deviation value to a fourth operation risk characteristic value, querying a corresponding fourth characteristic value weight according to the fourth operation risk characteristic value.

[0094] Step 306, obtaining a balance priority index of each candidate energy storage battery by fusing the operation risk characteristic value and the corresponding characteristic value weight of each candidate energy storage battery.

[0095] It should be noted that, in order to ensure that the balance priority index is a quantitative result that fits the actual demand of the energy storage system under the influence of multiple factors such as voltage deviation risk, capacity health influence, state estimation reliability and single vulnerability, a balance priority quantization model can be set to fuse the obtained operation risk characteristic value and the corresponding characteristic value weight, so as to obtain the balance priority index of each candidate energy storage battery.

[0096] As an example, step 306 comprises: inputting the operation risk feature value of each candidate energy storage battery and the corresponding feature value weight into the balanced priority quantification model, fusing the operation risk feature value of each candidate energy storage battery and the corresponding feature value weight through the balanced priority quantification model, and obtaining the balanced priority index of each candidate energy storage battery.

[0097] The fusion process of the balanced priority quantification model can be specifically as follows:

[0098]

[0099] wherein, is the balanced priority index, is the first operation risk feature value, is the second operation risk feature value, is the third operation risk feature value, is the fourth operation risk feature value, is the first feature value weight, is the second feature value weight, is the third feature value weight, is the fourth feature value weight.

[0100] In the above embodiment, first, based on the battery voltage of the energy storage system, a plurality of candidate energy storage batteries satisfying the balancing control condition are selected from the energy storage system, which can select the candidate energy storage batteries that need to participate in the balancing control with faster detection efficiency and lower detection cost, and then the balanced priority index of each candidate energy storage battery is obtained by fusing the real-time determined operation risk feature value and the feature value weight, which can accurately reflect the risk emergency degree and balancing necessity of different candidate energy storage batteries, and then more accurately evaluate the balancing priority of different candidate energy storage batteries affected by the operation risk feature information, so as to lay a foundation for further improving the effect of balancing control of the energy storage battery.

[0101] In one embodiment, according to the battery voltage of the energy storage system, a plurality of candidate energy storage batteries satisfying the balancing control condition in the energy storage system are detected, comprising:

[0102] If it is detected that the battery voltage is abnormal, the voltage balancing control is performed on all energy storage batteries of the energy storage system, and after the voltage balancing control is completed, the candidate energy storage batteries satisfying the balancing control condition are selected from all energy storage batteries; if it is detected that the battery voltage is not abnormal, all energy storage batteries are regarded as candidate energy storage batteries satisfying the balancing control condition.

[0103] It should be noted that in the process of screening a plurality of candidate energy storage batteries in the energy storage system, different pre-detection logics will be adopted based on abnormal conditions of the battery voltage; specifically, in the case of abnormal battery voltage, it indicates that the energy storage system is currently in an emergency risk state such as overcharge, overdischarge or local short circuit, and then the voltage balancing control is performed on all energy storage batteries first, and after all energy storage batteries are relatively leveled, the selection of candidate energy storage batteries is performed, and in the case where the battery voltage is not abnormal, it indicates that the energy storage system is in a stable running state, at this time all energy storage batteries are selected as candidate energy storage batteries that meet the balancing control condition, so as to orderly execute the subsequent balancing control.

[0104] As an example, the single cell voltage of all energy storage batteries in the energy storage system is obtained, if there is a single cell voltage greater than a preset single cell voltage threshold in all single cell voltages, it is determined that the battery voltage is abnormal, and then the voltage balancing control is performed on all energy storage batteries of the energy storage system, and after all energy storage batteries complete the balancing control, the candidate energy storage batteries that meet the balancing control condition are selected from all energy storage batteries; if all single cell voltages are less than or equal to the preset single cell voltage threshold, it is determined that the battery voltage is not abnormal, and all energy storage batteries are selected as candidate energy storage batteries that meet the balancing control condition.

[0105] As another example, the group voltage difference value of the battery pack to which each energy storage battery in the energy storage system belongs is obtained, if there is a group voltage difference value greater than a preset group voltage difference threshold in all group voltage difference values, it is determined that the battery voltage is abnormal, and then the voltage balancing control is performed on all energy storage batteries of the energy storage system, and after all energy storage batteries complete the balancing control, the candidate energy storage batteries that meet the balancing control condition are selected from all energy storage batteries; if all group voltage difference values are less than or equal to the preset group voltage difference threshold, it is determined that the battery voltage is not abnormal, and all energy storage batteries are selected as candidate energy storage batteries that meet the balancing control condition. In this way, the voltage of the plurality of energy storage batteries in the energy storage system can be relatively balanced, thereby avoiding interference with the selection of candidate energy storage batteries due to local voltage abnormalities, so that the selection of candidate energy storage batteries is performed under the premise that the energy storage system is in a safe running state, rather than relying on the size relationship between the battery voltage and the battery voltage threshold, thereby making the selection of candidate energy storage batteries more in line with the real running state of the battery and more reliable, so as to improve the selection accuracy of candidate energy storage batteries.

[0106] In one embodiment, the running risk characteristic value and the corresponding characteristic value weight of each candidate energy storage battery after being affected by the running risk characteristic information are determined, including:

[0107] The first voltage characteristic value of each candidate energy storage battery and the second voltage characteristic value of the battery group to which each candidate energy storage battery belongs are obtained; the voltage deviation characteristic value of each candidate energy storage battery is determined according to the first voltage characteristic value and the second voltage characteristic value; the first operation risk characteristic value is obtained by fusing the equalization control voltage difference threshold value, the equalization stop voltage difference threshold value and the voltage deviation characteristic value of each candidate energy storage battery; the voltage change characteristic value of each candidate energy storage battery is determined; the first basic characteristic value weight of the first operation risk characteristic value is corrected according to the voltage change characteristic value to obtain the first characteristic value weight.

[0108] It should be noted that, considering the dynamic change characteristics of the voltage deviation risk information on the operation risk of the energy storage battery and the multi-scale characteristic difference of the voltage deviation risk, a specific calculation method needs to be set to determine the first operation risk characteristic value and the first characteristic value weight; the first voltage characteristic value represents the actual voltage of a single energy storage battery in the energy storage system, which is used to reflect the influence of the individual energy storage battery on the voltage deviation risk, and the second voltage characteristic value represents the average voltage of the battery group to which a single energy storage battery in the energy storage system belongs, which is used to reflect the influence of the energy storage batteries on the voltage deviation risk; the voltage change characteristic value represents the change trend of the energy storage battery in a unit time, the first basic characteristic value weight can be set in advance, and the correction of the first basic characteristic value by the voltage change characteristic value can make the weight distribution for the voltage risk accurately conform to the real-time risk emergency degree, thereby realizing the intelligent quantification of the operation risk affected by the voltage deviation risk information.

[0109] As an example, the real-time single battery voltage of each candidate energy storage battery and the real-time average voltage of the battery group to which each candidate energy storage battery belongs are obtained; the absolute value of the difference between the real-time single battery voltage and the real-time average voltage of each candidate energy storage battery is taken as the voltage deviation characteristic value of each candidate energy storage battery; the equalization control voltage difference threshold value, the equalization stop voltage difference threshold value and the voltage deviation characteristic value of each candidate energy storage battery are jointly input into a first preset characteristic value fusion formula to obtain the first operation risk characteristic value; the voltage change characteristic value of each candidate energy storage battery is determined according to the change relationship of the actual voltage of each candidate energy storage battery with time; the voltage change characteristic value and the first basic characteristic value are jointly input into a first preset weight fusion formula to obtain the first characteristic value weight.

[0110] In an implementable manner, the first voltage characteristic value is represented as , the second voltage characteristic value is represented as , and the voltage deviation characteristic value is represented as , then ; the first preset characteristic value fusion formula can be specifically as follows:

[0111]

[0112] wherein, is a first operation risk characteristic value, is a voltage deviation characteristic value, is a balancing control voltage difference threshold value, which can be 30mV or 40mV, etc., is a balancing stop voltage difference threshold value, which can be 5mV or 6mV, etc.; the first preset weight fusion formula can be specifically as follows:

[0113]

[0114] wherein, is a first characteristic value weight, is a first basic characteristic value weight, which can be obtained by pre-setting, for example is 0.55 or 0.56, etc., and k is a correction coefficient, which can be a constant such as 0.5 or 0.6, is a voltage change characteristic value, wherein the greater the voltage change characteristic value, the higher the voltage deviation risk.

[0115] In the above embodiments, by fusing the voltage deviation characteristic value, the balancing control voltage difference threshold value and the balancing stop voltage difference threshold value, the first operation risk characteristic value is calculated, which can accurately match the dynamic change characteristics of the operation risk of the energy storage battery and the multi-scale feature difference of the voltage deviation risk. On the other hand, by correcting the first basic characteristic value with the voltage change characteristic value, the weight distribution for the voltage risk can accurately conform to the real-time risk emergency degree, so as to further lay a foundation for improving the effect of balancing control of the energy storage battery.

[0116] In one of the embodiments, determining the operation risk characteristic value and the corresponding characteristic value weight presented by each candidate energy storage battery after being affected by the operation risk characteristic information includes:

[0117] obtain a first state-of-charge characteristic value of each candidate energy storage battery and a second state-of-charge characteristic value of a battery pack to which each candidate energy storage battery belongs; determine a state-of-charge deviation characteristic value of each candidate energy storage battery according to the first state-of-charge characteristic value and the second state-of-charge characteristic value; obtain a second operation risk characteristic value by fusing an equalization control state-of-charge difference value threshold, an equalization stop state-of-charge difference value threshold and the state-of-charge deviation characteristic value of each candidate energy storage battery; determine a state-of-charge difference characteristic value, a first characteristic value under an ambient temperature and a second characteristic value under an operation stage of each candidate energy storage battery; obtain a state-of-charge confidence of each candidate energy storage battery according to a state-of-charge identifier of each candidate energy storage battery, wherein the state-of-charge identifier is used to distinguishively identify a category of the estimated state-of-charge of the candidate energy storage battery; and correct a second basic characteristic value weight of the second operation risk characteristic value according to the state-of-charge difference characteristic value, the first characteristic value, the second characteristic value and the state-of-charge confidence, to obtain a second characteristic value weight.

[0118] It should be noted that, similar to the voltage deviation risk information, considering the dynamic change characteristic of the capacity health risk information on the operation risk of the energy storage battery and the multi-scale characteristic difference of the capacity health risk, a specific calculation method needs to be set to determine the second operation risk characteristic value and the second characteristic value weight; the first state-of-charge characteristic value represents the actual state-of-charge of a single energy storage battery in the energy storage system, and is used to reflect the influence of the individual energy storage battery on the capacity health risk, and the second state-of-charge characteristic value represents the average state-of-charge of a battery pack to which a single energy storage battery in the energy storage system belongs, and is used to reflect the influence of the energy storage batteries on the capacity health risk; the state-of-charge deviation characteristic value represents the deviation degree between the actual state-of-charge of a single energy storage battery and the reference state-of-charge, and the state-of-charge difference characteristic value represents the overall dispersion degree of the state-of-charge among a plurality of energy storage batteries, the former reflects the deviation size of a single energy storage battery in the state-of-charge from the reference standard, and the latter reflects the distribution difference of a plurality of energy storage batteries in the state-of-charge, the first basic characteristic value is corrected by the voltage change characteristic value, which can make the weight distribution for the capacity health risk accurately conform to the real-time risk emergency degree, thereby realizing the intelligent quantification of the operation risk affected by the voltage deviation risk information; the second basic characteristic value weight can be obtained in advance, and specifically can be 0.4 or 0.5, etc.; the state-of-charge confidence represents the reliability of the state-of-charge of the energy storage battery estimated by the current estimation method, and can be obtained by querying the state-of-charge identifier of the candidate energy storage battery, the state-of-charge identifier is used to distinguishively identify the category of the estimated candidate energy storage battery, for example, in an implementable manner, the state-of-charge confidence can be represented as if it is determined through the state-of-charge identifier that the category of the estimated candidate energy storage battery is “OCV (Open Circuit Voltage) calibration state”, then , if the category of the candidate energy storage battery is estimated as "state of charge" by the state of charge identification determination, , wherein, is the cumulative error of the Coulomb counting estimation, which can be obtained by the following formula:

[0119]

[0120] , wherein, is the cumulative error of the Coulomb counting estimation, is the SOC estimated by the Coulomb counting method, which is derived from the integration of the current, is the reference calibration value, which can be obtained by looking up the OCV-SOC curve after standing, is the duration of continuous operation, which can be the time difference from the last OCV calibration, if the category of the candidate energy storage battery is estimated as "empty" by the state of charge identification determination, .

[0121] As an example, the real-time state of charge of each candidate energy storage battery and the average state of charge of the battery pack to which each candidate energy storage battery belongs are obtained; the absolute value of the difference between the real-time single cell voltage of each candidate energy storage battery and the real-time average voltage is taken as the state of charge deviation feature value of each candidate energy storage battery; the equalization control state of charge difference threshold, the equalization stop state of charge difference threshold, and the state of charge deviation feature value of each candidate energy storage battery are collectively input into a second preset feature value fusion formula to obtain a second operation risk feature value; the state of charge difference feature value of each candidate energy storage battery, the first feature value at the ambient temperature, and the second feature value at the running stage are determined; the state of charge identification of each candidate energy storage battery is taken as an index to obtain the state of charge confidence of each candidate energy storage battery; the state of charge difference feature value, the first feature value, the second feature value, the state of charge confidence, and the second basis feature value weight of the second operation risk feature value are collectively input into a second preset weight fusion formula to obtain a second feature value weight.

[0122] In an implementable manner, assuming that the first state of charge feature value is represented as , the second state of charge feature value is represented as , and the state of charge deviation feature value is represented as , then the state of charge deviation feature value ; the second preset feature value fusion formula can be specifically as follows:

[0123]

[0124] , wherein, is the second operation risk feature value, a state-of-charge difference characteristic value, a state-of-charge difference threshold value for equalization control, which can be 5% or 6%, etc., a state-of-charge difference threshold value for equalization stop, which can be 1% or 2%, etc.; the second preset weight fusion formula can be specifically as follows:

[0125]

[0126] wherein, a second characteristic value weight, a second basic characteristic value weight, which can be obtained in advance, a state-of-charge difference characteristic value, a state-of-charge confidence, a first characteristic value, a second characteristic value.

[0127] In the above embodiment, by fusing the state-of-charge deviation characteristic value, the state-of-charge difference threshold value for equalization control, and the state-of-charge difference threshold value for equalization stop, the second operation risk characteristic value is calculated, which can accurately match the dynamic change characteristics of the operation risk of the energy storage battery and the multi-scale characteristic difference of the capacity health risk. On the other hand, by the state-of-charge difference characteristic value, the first characteristic value, the second characteristic value, and the state-of-charge confidence, the second basic characteristic value is corrected, which can make the weight distribution for the capacity health risk accurately conform to the real-time risk emergency degree, so as to further lay a foundation for improving the effect of equalization control of the energy storage battery.

[0128] In one embodiment, determining the state-of-charge difference characteristic value, the first characteristic value under the ambient temperature, and the second characteristic value under the running phase of each candidate energy storage battery comprises:

[0129] obtaining a state-of-charge difference value of each candidate energy storage battery; performing normalization processing on the state-of-charge difference value to obtain a state-of-charge difference characteristic value; querying a first characteristic value according to an ambient temperature value of each candidate energy storage battery; and querying a second characteristic value according to a running phase identifier of the energy storage system.

[0130] It should be noted that for different equalization control scenarios, the calculation of each characteristic value can be adaptively performed to ensure that the correction of the second characteristic value weight of the second operation risk characteristic value can be adapted to the equalization control requirements of the current scenario; the running phase identifier is used to distinguish the running phase in which the energy storage system is currently located.

[0131] As an example, the absolute value of the difference between the first state-of-charge characteristic value of each candidate energy storage battery and the standard deviation of the state-of-charge of all energy storage batteries in the battery pack is taken as the state-of-charge difference value of each candidate energy storage battery, wherein the state-of-charge difference value The calculation formula is as follows:

[0132]

[0133] in, This represents the difference in state of charge. The characteristic value of the first state of charge. The standard deviation of the state of charge is used as the reference value. The difference in the state of charge is normalized to obtain the characteristic value of the difference in the state of charge. The first characteristic value is obtained by querying the ambient temperature of each candidate energy storage battery. The second characteristic value is obtained by querying the operation stage of the energy storage system.

[0134] The specific steps for normalizing the difference in state of charge can be summarized as follows:

[0135]

[0136] in, This represents the difference in state of charge. These are characteristic values ​​of the difference in state of charge. It can be understood that by normalizing the difference in state of charge, the typical difference range of 0%~10% can be mapped to 0~1.

[0137] In one feasible approach, suppose the first eigenvalue is represented as If the ambient temperature value The query will retrieve the first feature value. If the ambient temperature value The query will retrieve the first feature value. If the ambient temperature value The query will retrieve the first feature value. Assume the second eigenvalue is represented as If the energy storage system is determined to be in a "charging" state based on the operational phase indicator, then because the capacity difference needs to be quickly repaired during the charging state, at this time... If the energy storage system is determined to be in a "discharging" state based on the operational phase identifier, then a basic weight can be set, and at this time... If the energy storage system is determined to be in a "quiet" state based on the operational phase identifier, then the weight of the quiet state is set to secondary, and thus at this time... .

[0138] In one embodiment, determining the operational risk characteristic value and corresponding characteristic value weight of each candidate energy storage battery after being affected by operational risk characteristic information includes:

[0139] According to the state of charge identifier of each candidate energy storage battery, a third operation risk characteristic value is queried; according to the state of charge identifier, a state of charge confidence of each candidate energy storage battery is queried; and according to the state of charge confidence, a third basic characteristic value weight of the third operation risk characteristic value is corrected to obtain a third characteristic value weight.

[0140] It should be noted that, since the state of charge identifier can directly reflect the core attribute of the energy storage battery in the state of charge dimension, and then the third operation risk characteristic value can be directly queried through the state of charge identifier, thereby reflecting the basic quantitative level of the third operation risk characteristic value after being affected by the operation state risk information; for example, in an implementable manner, assuming that the third operation risk characteristic value is , if the estimation category of the state of charge is determined as "OCV calibration" through the state of charge identifier, , if the estimation category of the state of charge is determined as "Coulomb counting + voltage auxiliary" through the state of charge identifier, , if the estimation category of the state of charge is determined as "pure Coulomb counting" through the state of charge identifier, ; further, through the state of charge identifier, the third basic characteristic value weight of the third operation risk characteristic value can be queried, for example, in an implementable manner, assuming that the state of charge confidence is represented as , if the estimation category of the state of charge is determined as "OCV calibration" through the state of charge identifier, , if the estimation category of the state of charge is determined as "pure Coulomb counting" through the state of charge identifier, .

[0141] As an example, the third operation risk characteristic value is queried with the state of charge identifier of each candidate energy storage battery as an index; the state of charge confidence of each candidate energy storage battery is queried with the state of charge identifier as an index; and the third basic characteristic value weight of the third operation risk characteristic value is corrected according to the state of charge confidence to obtain the third characteristic value weight.

[0142] Wherein, the third basic characteristic value weight of the third operation risk characteristic value is corrected according to the state of charge confidence to obtain the third characteristic value weight, and the specific formula is as follows:

[0143]

[0144] Wherein, is the third characteristic value weight, is the third basic characteristic value weight, which can be specifically 0.1, is the state of charge confidence; it can be understood that the lower the state of charge confidence, the lower the balanced control priority.

[0145] In the above embodiment, by identifying the operating state of the candidate energy storage battery through the state of charge, the basic risk level under different state of charge attributes can be accurately identified, and the dynamic correction of the third basic feature value weight combined with the state of charge confidence makes the weight distribution of the operating risk accurately conform to the real-time risk emergency level, so as to further lay a foundation for improving the effect of balancing control of the energy storage battery.

[0146] In one embodiment, the operating risk feature value presented by each candidate energy storage battery after being affected by the operating risk feature information and the corresponding feature value weight are determined, including:

[0147] The real-time health degree, temperature deviation value and actual temperature value of each candidate energy storage battery are obtained; the fourth operating risk feature value is obtained by fusing the real-time health degree, temperature deviation value and actual temperature value; the real-time health degree of each candidate energy storage battery is determined; and the fourth basic feature value weight of the fourth operating risk feature value is corrected according to the real-time health degree to obtain the fourth feature value weight.

[0148] As an example, the actual temperature value, reference temperature value and real-time health of each candidate energy storage battery are obtained, the actual temperature value and the reference temperature value are subtracted to obtain the temperature deviation value of each candidate energy storage battery; the fourth operating risk feature value is obtained by inputting the real-time health degree, temperature deviation value and actual temperature value into the third preset feature value fusion formula; and the fourth feature value weight is obtained by inputting the real-time health degree into the third preset weight fusion formula.

[0149] In an implementable manner, the real-time health degree is represented as , and the temperature deviation value is represented as The third preset feature fusion formula can be specifically as follows:

[0150]

[0151] Among them, is the fourth operating risk feature value, is the real-time health degree, is the temperature deviation value, is the temperature deviation threshold, which can be 40℃ or 45℃, etc.; and the third preset weight fusion formula can be specifically as follows:

[0152] η 4 = min [ 0.3, η 4 ' + 0.25 ∗ ( 1- SOH i / 100 ) ]

[0153] Among them, is the fourth feature value weight, is the fourth basic feature value weight, which can be obtained by being set in advance, for example 0.05 or 0.06, etc. For example, in an implementable manner, assuming that 0.05, if the candidate energy storage battery is a new battery, 0.05 is calculated as the fourth basic characteristic value weight, if the candidate energy storage battery is an aged battery, 0.1 is calculated as the fourth basic characteristic value weight, if the candidate energy storage battery is an aged battery, 0.125 is calculated as the fourth basic characteristic value weight, if the candidate energy storage battery is an aged battery.

[0154] In the above embodiment, the single cell vulnerability of the candidate energy storage battery is determined by the real-time health degree, the temperature deviation value and the actual temperature value, which can accurately identify the risk level under different thermal correlation attributes, and the dynamic correction of the fourth basic characteristic value weight combined with the real-time health degree makes the weight allocation for the thermal correlation risk accurately conform to the real-time risk emergency degree, so as to further lay a foundation for improving the effect of balancing control of the energy storage battery.

[0155] In one embodiment, the first characteristic value weight is , the second characteristic value weight is , the third characteristic value weight is , and the fourth characteristic value weight is , wherein , and each satisfy: , , , , , and satisfy: , .

[0156] It should be noted that due to the thermal runaway of the energy storage battery, the weight is set according to a certain weight size relationship, for example, , to ensure that voltage abnormalities are processed first, life orientation is second, fragile attributes are used as auxiliary decision-making, and state estimation reliability is used as a penalty for low credible data, wherein the sum of the first characteristic value weight, the second characteristic value weight, the third characteristic value weight and the fourth characteristic value weight is 1, and each characteristic value weight is constrained in the corresponding range.

[0157] In one embodiment, satisfies: .

[0158] ​It should be noted that, in order to avoid the situation of false balancing of the energy storage battery in the energy storage system, the balancing priority affected by the operation risk feature information can be actively reduced, for example, the balancing priority affected by the operation risk feature information can be set to 0. .

[0159] In one embodiment, after the balancing control is completed for the target energy storage battery, all balancing priority indicators are updated, and the target energy storage battery participating in the balancing control is iteratively selected based on all updated balancing priority indicators, and before the balancing control of all candidate energy storage batteries is completed, the energy storage battery balancing control method further comprises:

[0160] obtaining an associated feature value between the voltage and the state of charge of the target energy storage battery; in the case where the associated feature value is greater than or equal to a preset associated feature value threshold, performing voltage balancing control and capacity balancing control on the target energy storage battery; in the case where the associated feature value is less than the preset associated feature value threshold, performing capacity balancing control on the target energy storage battery.

[0161] It should be noted that, in order to accurately distinguish the current operating phase of the target energy storage battery and avoid waste of balancing control resources, the associated feature value can be set, wherein the associated feature value represents the degree of linkage response between the actual voltage and the actual state of charge of the target energy storage battery, which can be the slope of the voltage-SOC curve, and the specific balancing control strategy can be set based on the size relationship between the associated feature value and the preset associated feature value threshold. It can be understood that the preset associated feature value threshold of different types of target energy storage batteries is different, for example, in one implementable manner, the preset associated feature value threshold of the lithium iron phosphate battery is set to 0.8-1.5 mV / % SOC, and the preset associated feature value threshold of the nickel-cobalt-manganese lithium battery is set to 1.5-3.0 mV / % SOC; further, in the case where the associated feature value is greater than or equal to the preset associated feature value threshold, it indicates that the target energy storage battery is in the platform period, and only capacity balancing control is needed, while in the case where the associated feature value is less than the preset associated feature value threshold, it indicates that the target energy storage battery is not in the platform period, and voltage balancing control and capacity balancing control are needed.

[0162] As an example, the associated characteristic value is calculated according to the voltage and state of charge of the target energy storage battery; in a case where the associated characteristic value is greater than or equal to a preset associated characteristic value threshold, it is determined that the target energy storage battery is in a platform period, and voltage equalization control and capacity equalization control are performed on the target energy storage battery; in a case where the associated characteristic value is less than the preset associated characteristic value threshold, it is determined that the target energy storage battery is not in the platform period, and capacity equalization control is performed on the target energy storage battery. In this way, the platform period and the non-platform period are distinguished by the associated characteristic value, different equalization control strategies can be set accordingly, so that the voltage equalization control process is skipped when the target energy storage battery is in the platform period, thereby reducing the start-stop frequency and capacity loss of the equalization circuit. Therefore, while laying a foundation for improving the effect of equalization control on the energy storage battery, the service life of the energy storage battery is also extended.

[0163] In one embodiment, the energy storage battery equalization control method further comprises:

[0164] In the process of performing capacity equalization control on the target energy storage battery, the real-time state of charge value of the target energy storage battery and the state of charge reference value of the energy storage system are obtained; the state of charge deviation value of the target energy storage battery is determined according to the real-time state of charge value and the state of charge reference value; in a case where the state of charge deviation value is less than or equal to a preset state of charge deviation value threshold, the capacity equalization control on the target energy storage battery is stopped.

[0165] It should be noted that the state of charge reference value can be the average state of charge of all energy storage batteries in the energy storage system, or a pre-set state of charge reference value. The preset state of charge deviation value threshold can be obtained in advance according to the battery type and system equalization accuracy requirement. By comparing the size relationship between the state of charge deviation value and the preset state of charge deviation value threshold, the dynamic monitoring of the capacity equalization control effect can be realized. In a case where the state of charge deviation value is less than or equal to the preset state of charge deviation value threshold, it indicates that the state of charge of the target energy storage battery has been consistent with the level of the energy storage system, and at this time it is indicated that the capacity equalization control has been completed.

[0166] As an example, in the process of performing capacity equalization control on the target energy storage battery, the real-time state of charge value of the target energy storage battery and the state of charge reference value of the energy storage system are obtained; according to the real-time state of charge value and the state of charge reference value, the state of charge deviation value of the target energy storage battery is determined; in the case of detecting that the state of charge deviation value is less than or equal to the preset state of charge deviation value threshold, the capacity equalization control of the target energy storage battery is stopped. In this way, the state of charge deviation threshold is used as the stopping standard to ensure that the state of charge of all target energy storage batteries eventually converges to the reference value, avoiding the situation that part of the energy storage batteries become the equalization control target due to excessive deviation, thereby improving the charging and discharging efficiency and operation stability of the energy storage system. At the same time, it also avoids the situation that the equalization control is mistakenly stopped due to the voltage difference as the closing condition in the platform period, so as to improve the accuracy of the equalization control of the energy storage battery.

[0167] In an implementable manner, referring to Figure 3 , Figure 3 The flowchart for equalization control of the energy storage battery is shown in the figure, wherein first, it is determined whether the battery voltage of the energy storage system is abnormal. In the case that the battery voltage is abnormal, the voltage equalization control is performed on all energy storage batteries of the energy storage system, and the equalization control condition is waited for recovery. In the case that the battery voltage is not abnormal, it indicates that the energy storage system is in a normal operation state, and then the candidate energy storage batteries satisfying the equalization control condition are selected from all energy storage batteries. Further, the equalization priority indicators corresponding to the multiple candidate energy storage batteries satisfying the equalization control condition in the energy storage system are obtained, and the equalization priority indicators are sorted in descending order according to the size, so that the target energy storage battery participating in the equalization control is first selected from all candidate energy storage batteries. Further, it is determined whether the target energy storage battery is in the platform period. If the target energy storage battery is in the platform period, the capacity equalization control is directly performed on the target energy storage battery. If the target energy storage battery is not in the platform period, the voltage equalization control and the capacity equalization control are performed on the target energy storage battery. Further, the equalization priority indicators are updated periodically, and the target energy storage battery participating in the equalization control is iteratively selected until the equalization control of all candidate energy storage batteries is completed.

[0168] Since the equalization priority index represents the equalization priority of the candidate energy storage battery after being affected by the risk characteristic information, and the target energy storage battery participating in the equalization control for the first time is screened by relying on the equalization priority index, the potential operation risks of different energy storage batteries in the energy storage system can be accurately evaluated, so that the purpose of quantitatively evaluating the execution object of the equalization control is achieved. Further, after the equalization control is performed on the target energy storage battery participating in the equalization control for the first time, the target energy storage battery participating in the equalization control is dynamically adjusted until all candidate energy storage batteries complete the equalization control, so that the purpose of adaptively matching the external operation condition of the energy storage system in the process of performing the equalization control on the energy storage battery is achieved, thereby overcoming the technical defects that the pre-set energy storage battery equalization control strategy cannot match the actual equalization control demand of the energy storage battery due to the fact that the external operation condition of the energy storage system is in dynamic change, and thus the effect of performing the equalization control on the energy storage battery is improved.

[0169] It should be understood that, although each step in the flowchart involved in the above embodiments is displayed in sequence according to the arrow, these steps are not necessarily executed in sequence according to the order of the arrow. Unless otherwise specified herein, the execution of these steps is not strictly limited in sequence, and these steps can be executed in other orders. Moreover, at least part of the steps in the flowchart involved in the above embodiments can include multiple steps or multiple stages, which are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily sequential, but can be alternately executed with at least part of other steps or steps or stages in other steps.

[0170] Based on the same inventive concept, the embodiments of the present application also provide an energy storage battery equalization control device for implementing the above-mentioned energy storage battery equalization control method. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme described in the above method, so the specific limitations in one or more energy storage battery equalization control device embodiments provided below can refer to the limitations of the energy storage battery equalization control method in the above text, which will not be repeated here.

[0171] In one exemplary embodiment, as shown in Figure 4 An energy storage battery equalization control device is provided, applied to an energy storage system, and includes an acquisition module 401, a selection module 402, and an equalization control module 403. The acquisition module 401 is configured to acquire risk characteristic information of each candidate energy storage battery in the energy storage system, and the selection module 402 is configured to select a target energy storage battery participating in the equalization control for the first time from the candidate energy storage batteries according to an equalization priority index of each candidate energy storage battery, the equalization priority index being determined according to the risk characteristic information of each candidate energy storage battery. The equalization control module 403 is configured to perform the equalization control on the target energy storage battery participating in the equalization control for the first time.

[0172] The acquisition module 401 is configured to acquire an equalization priority index corresponding to each of a plurality of candidate energy storage cells satisfying an equalization control condition in the energy storage system, where the equalization priority index represents an equalization priority of the candidate energy storage cell affected by operation risk characteristic information, and the operation risk characteristic information includes at least one of voltage deviation risk information, capacity health risk information, operation state risk information, and thermal correlation risk information.

[0173] The selection module 402 is configured to select, according to all the equalization priority indexes, a target energy storage cell participating in equalization control from the plurality of candidate energy storage cells for the first time.

[0174] The equalization control module 403 is configured to update all the equalization priority indexes after completing equalization control on the target energy storage cell, and iteratively select a target energy storage cell participating in equalization control based on all the updated equalization priority indexes until equalization control is completed on all the candidate energy storage cells.

[0175] In one embodiment, the acquisition module 401 is further configured to:

[0176] detect, according to a battery voltage of the energy storage system, a plurality of candidate energy storage cells satisfying an equalization control condition in the energy storage system; determine an operation risk characteristic value and a corresponding characteristic value weight of each candidate energy storage cell affected by operation risk characteristic information, where the operation risk characteristic value includes at least one of a first operation risk characteristic value affected by voltage deviation risk information, a second operation risk characteristic value affected by capacity health risk information, a third operation risk characteristic value affected by operation state risk information, and a fourth operation risk characteristic value affected by thermal correlation risk information, and the characteristic value weight includes at least one of a first characteristic value weight corresponding to the first operation risk characteristic value, a second characteristic value weight corresponding to the second operation risk characteristic value, a third characteristic value weight corresponding to the third operation risk characteristic value, and a fourth characteristic value weight corresponding to the fourth operation risk characteristic value; and obtain an equalization priority index of each candidate energy storage cell by fusing the operation risk characteristic value and the corresponding characteristic value weight of each candidate energy storage cell.

[0177] In one embodiment, the acquisition module 401 is further configured to:

[0178] If it is detected that the battery voltage is abnormal, performing voltage equalization control on all energy storage cells of the energy storage system, and selecting, after completing the voltage equalization control, a candidate energy storage cell satisfying the equalization control condition from all the energy storage cells; and if it is detected that the battery voltage is not abnormal, regarding all the energy storage cells as candidate energy storage cells satisfying the equalization control condition.

[0179] In one embodiment, the acquisition module 401 is further configured to:

[0180] obtain a first voltage characteristic value of each candidate energy storage battery and a second voltage characteristic value of a battery pack to which each candidate energy storage battery belongs; determine a voltage deviation characteristic value of each candidate energy storage battery according to the first voltage characteristic value and the second voltage characteristic value; obtain a first operation risk characteristic value by fusing an equalization control voltage difference threshold value, an equalization stop voltage difference threshold value and the voltage deviation characteristic value of each candidate energy storage battery; determine a voltage change characteristic value of each candidate energy storage battery; correct a first basic characteristic value weight of the first operation risk characteristic value according to the voltage change characteristic value to obtain a first characteristic value weight.

[0181] In one of the embodiments, the obtaining module 401 is further configured to:

[0182] obtain a first state of charge characteristic value of each candidate energy storage battery and a second state of charge characteristic value of a battery pack to which each candidate energy storage battery belongs; determine a state of charge deviation characteristic value of each candidate energy storage battery according to the first state of charge characteristic value and the second state of charge characteristic value; obtain a second operation risk characteristic value by fusing an equalization control state of charge difference threshold value, an equalization stop state of charge difference threshold value and the state of charge deviation characteristic value of each candidate energy storage battery; determine a state of charge difference characteristic value, a first characteristic value under an environmental temperature and a second characteristic value under an operation phase of each candidate energy storage battery; query a state of charge confidence of each candidate energy storage battery according to a state of charge identifier of each candidate energy storage battery, wherein the state of charge identifier is used to distinguish a category of the estimated state of charge of the candidate energy storage battery; correct a second basic characteristic value weight of the second operation risk characteristic value according to the state of charge difference characteristic value, the first characteristic value, the second characteristic value and the state of charge confidence to obtain a second characteristic value weight.

[0183] In one of the embodiments, the obtaining module 401 is further configured to:

[0184] obtain a state of charge difference value of each candidate energy storage battery; perform normalization processing on the state of charge difference value to obtain a state of charge difference characteristic value; query a first characteristic value according to an environmental temperature value of each candidate energy storage battery; query a second characteristic value according to an operation phase identifier of the energy storage system.

[0185] In one of the embodiments, the obtaining module 401 is further configured to:

[0186] query a third operation risk characteristic value according to a state of charge identifier of each candidate energy storage battery; query a state of charge confidence of each candidate energy storage battery according to the state of charge identifier; correct a third basic characteristic value weight of the third operation risk characteristic value according to the state of charge confidence to obtain a third characteristic value weight.

[0187] In one of the embodiments, the acquisition module 401 is further configured to:

[0188] acquire the real-time health degree, the temperature deviation value and the actual temperature value of each candidate energy storage battery; obtain a fourth operation risk characteristic value by fusing the real-time health degree, the temperature deviation value and the actual temperature value; and correct a fourth basic characteristic value weight of the fourth operation risk characteristic value according to the real-time health degree to obtain a fourth characteristic value weight.

[0189] In one of the embodiments, the first characteristic value weight is , the second characteristic value weight is , the third characteristic value weight is , and the fourth characteristic value weight is , wherein , and each satisfy: , , , , , and satisfy: , .

[0190] In one of the embodiments, satisfies: .

[0191] In one of the embodiments, the energy storage battery equalization control device is further configured to:

[0192] acquire an associated characteristic value between the voltage and the state of charge of the target energy storage battery; perform voltage equalization control and capacity equalization control on the target energy storage battery in a case where the associated characteristic value is greater than or equal to a preset associated characteristic value threshold; and perform capacity equalization control on the target energy storage battery in a case where the associated characteristic value is less than the preset associated characteristic value threshold.

[0193] In one of the embodiments, the energy storage battery equalization control device is further configured to:

[0194] acquire a real-time state of charge value of the target energy storage battery and a state of charge reference value of the energy storage system in a process of performing capacity equalization control on the target energy storage battery; determine a state of charge deviation value of the target energy storage battery according to the real-time state of charge value and the state of charge reference value; and stop the capacity equalization control on the target energy storage battery in a case where the state of charge deviation value is less than or equal to a preset state of charge deviation value threshold.

[0195] The modules in the energy storage battery equalization control device can be implemented by software, hardware, or a combination thereof. The modules can be embedded in or independent of a processor in the energy storage system in hardware form, or stored in a memory in the energy storage system in software form, so as to be called and executed by the processor to perform the operations corresponding to the modules.

[0196] In an example embodiment, an energy storage system is provided, which can include a terminal (such as a local management terminal) for monitoring and control. The internal structure of the terminal can be as shown in Figure 5 The terminal includes a processor, a memory, an input / output interface, a communication interface, a display unit, and an input device. The processor, the memory, and the input / output interface are connected through a system bus, and the communication interface, the display unit, and the input device are connected to the system bus through the input / output interface. The processor of the terminal is configured to provide computing and control capabilities and support the running of energy storage system related programs. The memory of the terminal includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program, and the internal memory provides an environment for the operating system and the computer program to run. The input / output interface of the terminal is configured to exchange information between the processor and external devices (such as a BMS and an inverter of the energy storage system). The communication interface of the terminal is configured to communicate with external devices (such as a remote monitoring platform) in a wired or wireless manner. The wireless manner can be implemented through WIFI, mobile cellular network, NFC (near field communication), or other technologies. When the computer program is executed by the processor of the terminal, an energy storage battery equalization control method (such as sending an equalization control instruction to the BMS and receiving battery state data) can be implemented. Those skilled in the art can understand that the structure shown in Figure 5 The structure shown in the above embodiment is merely a block diagram of the terminal structure related to the scheme of the present application, and does not constitute a limitation on the energy storage system to which the scheme of the present application is applied. Specifically, the energy storage system can further include battery packs, BMSs, inverters, and other core components. The terminal is only a control and interaction unit of the energy storage system, and the hardware thereof can include more or fewer components than those shown in the figure, or combine certain components, or have a different component arrangement according to actual needs.

[0197] In an example embodiment, a computer readable storage medium is provided, which stores a computer program. When the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0198] In an example embodiment, a computer program product is provided, which includes a computer program. When the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0199] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when the computer program is executed, the processes of the above-mentioned embodiments of the methods can be included. Any reference to memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical storage, high-density embedded non-volatile memory, resistive memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration but not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc. The database involved in the embodiments provided in the present application can include at least one of a relational database and a non-relational database. The non-relational database can include a distributed database based on a block chain, etc., without being limited thereto. The processor involved in the embodiments provided in the present application can be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., without being limited thereto.

[0200] Any combination of the technical features of the above embodiments can be made. In order to make the description simple, the above-mentioned technical features of the embodiments are not described in detail, however, as long as the combination of the technical features does not exist, it should be considered as the scope of the present application.

[0201] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of protection of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A method for equalizing control of energy storage batteries, characterized in that, The energy storage battery balancing control method, applied to energy storage systems, includes: The equalization priority index is obtained for each of the multiple candidate energy storage batteries that meet the equalization control conditions within the energy storage system. The equalization priority index characterizes the equalization priority of the candidate energy storage battery after being affected by operational risk characteristic information. The operational risk characteristic information includes at least two of the following: voltage deviation risk information, capacity health risk information, operational status risk information, and thermal correlation risk information. The equalization priority index is calculated using operational risk characteristic values ​​and characteristic weights determined by the energy storage system during real-time operation. The operational risk characteristic values ​​include at least two of the following: a first operational risk characteristic value affected by the voltage deviation risk information, a second operational risk characteristic value affected by the capacity health risk information, a third operational risk characteristic value affected by the operational status risk information, and a fourth operational risk characteristic value affected by the thermal correlation risk information. The characteristic weights include at least two of the following: a first characteristic weight corresponding to the first operational risk characteristic value, a second characteristic weight corresponding to the second operational risk characteristic value, a third characteristic weight corresponding to the third operational risk characteristic value, and a fourth characteristic weight corresponding to the fourth operational risk characteristic value. Based on all the equalization priority indicators, the target energy storage battery for participating in equalization control is selected for the first time from the plurality of candidate energy storage batteries. After completing the equalization control for the target energy storage battery, all equalization priority indicators are updated, and based on all updated equalization priority indicators, target energy storage batteries participating in the equalization control are iteratively selected until equalization control for all candidate energy storage batteries is completed; wherein, The first operational risk feature value is calculated by fusing voltage deviation feature value, equalization control voltage difference threshold, and equalization stop voltage difference threshold. The weight of the first feature value is obtained by correcting the weight of the first basic feature value using voltage change feature value. The second operational risk feature value is calculated by fusing state of charge deviation feature value, equalization control state of charge difference threshold, and equalization stop state of charge difference threshold. The weight of the second feature value is obtained by correcting the weight of the second basic feature value using state of charge difference feature value, first feature value, second feature value, and state of charge confidence. The third operational risk feature value is obtained by querying state of charge identifier. The weight of the third feature value is obtained by dynamically correcting the weight of the third basic feature value based on state of charge confidence. The fourth operational risk feature value is obtained by jointly determining real-time health, temperature deviation value, and actual temperature value. The weight of the fourth feature value is obtained by dynamically correcting the weight of the fourth basic feature value based on real-time health.

2. The energy storage battery equalization control method according to claim 1, characterized in that, The step of obtaining the equalization priority index corresponding to each of the multiple candidate energy storage batteries that meet the equalization control conditions in the energy storage system includes: Based on the battery voltage of the energy storage system, detect multiple candidate energy storage batteries in the energy storage system that meet the equalization control conditions; Determine the operational risk characteristic value and corresponding characteristic value weight of each candidate energy storage battery after being affected by the operational risk characteristic information; By integrating the operational risk characteristic value and the corresponding characteristic value weight of each candidate energy storage battery, a balanced priority index for each candidate energy storage battery is obtained.

3. The energy storage battery equalization control method according to claim 2, characterized in that, The step of detecting multiple candidate energy storage batteries in the energy storage system that meet the equalization control conditions based on the battery voltage of the energy storage system includes: If an abnormality is detected in the battery voltage, voltage equalization control is performed on all energy storage batteries in the energy storage system, and after the voltage equalization control is completed, candidate energy storage batteries that meet the equalization control conditions are selected from all the energy storage batteries. If no abnormality is detected in the battery voltage, then all the energy storage batteries are considered as candidate energy storage batteries that meet the equalization control conditions.

4. The energy storage battery equalization control method according to claim 2, characterized in that, The determination of the operational risk characteristic value and corresponding characteristic value weight of each candidate energy storage battery after being affected by the operational risk characteristic information includes: Obtain the first voltage characteristic value of each candidate energy storage battery and the second voltage characteristic value of the battery pack to which each candidate energy storage battery belongs; Based on the first voltage characteristic value and the second voltage characteristic value, the voltage deviation characteristic value of each candidate energy storage battery is determined; The first operational risk characteristic value is obtained by fusing the equalization control voltage difference threshold, the equalization stop voltage difference threshold, and the voltage deviation characteristic value of each candidate energy storage battery. Determine the voltage change characteristic value for each candidate energy storage battery; Based on the voltage change characteristic value, the weight of the first basic characteristic value of the first operating risk characteristic value is corrected to obtain the weight of the first characteristic value.

5. The energy storage battery equalization control method according to claim 2, characterized in that, The determination of the operational risk characteristic value and corresponding characteristic value weight of each candidate energy storage battery after being affected by the operational risk characteristic information includes: Obtain the first state of charge characteristic value of each candidate energy storage battery and the second state of charge characteristic value of the battery pack to which each candidate energy storage battery belongs; Based on the first state of charge characteristic value and the second state of charge characteristic value, the state of charge deviation characteristic value of each candidate energy storage battery is determined; The second operational risk characteristic value is obtained by integrating the equalization control state of charge difference threshold, the equalization stop state of charge difference threshold, and the state of charge deviation characteristic value of each candidate energy storage battery. Determine the characteristic value of the state of charge difference, the first characteristic value under the ambient temperature, and the second characteristic value under the operating stage for each candidate energy storage battery; Based on the state of charge (SOC) identifier of each candidate energy storage battery, the SOC confidence level of each candidate energy storage battery is obtained by querying, wherein the SOC identifier is used to distinguish and estimate the category of the SOC of the candidate energy storage battery. Based on the state of charge difference characteristic value, the first characteristic value, the second characteristic value, and the state of charge confidence, the weight of the second basic characteristic value of the second operational risk characteristic value is corrected to obtain the weight of the second characteristic value.

6. The energy storage battery equalization control method according to claim 5, characterized in that, The determination of the state-of-charge difference characteristic value, the first characteristic value under the ambient temperature, and the second characteristic value under the operating stage of each candidate energy storage battery includes: Obtain the state-of-charge difference value for each candidate energy storage battery; The state of charge difference value is normalized to obtain the state of charge difference feature value. The first feature value is obtained by querying the ambient temperature value of each candidate energy storage battery. The second feature value is obtained by querying based on the operating stage identifier of the energy storage system.

7. The energy storage battery equalization control method according to claim 2, characterized in that, The determination of the operational risk characteristic value and corresponding characteristic value weight of each candidate energy storage battery after being affected by the operational risk characteristic information includes: The third operational risk characteristic value is obtained by querying the state of charge identifier of each candidate energy storage battery. Based on the state of charge identifier, the state of charge confidence level of each candidate energy storage battery is obtained by querying. Based on the confidence level of the state of charge, the weight of the third basic feature value of the third operational risk feature value is corrected to obtain the weight of the third feature value.

8. The energy storage battery equalization control method according to claim 2, characterized in that, The determination of the operational risk characteristic value and corresponding characteristic value weight of each candidate energy storage battery after being affected by the operational risk characteristic information includes: Obtain the real-time health status, temperature deviation value, and actual temperature value of each candidate energy storage battery; The fourth operational risk characteristic value is obtained by integrating the real-time health status, the temperature deviation value, and the actual temperature value. Based on the real-time health status, the weight of the fourth basic feature value of the fourth operational risk feature value is corrected to obtain the weight of the fourth feature value.

9. The energy storage battery equalization control method according to claim 2, characterized in that, The first feature value weight is The weight of the second feature value is The weight of the third feature value is The weight of the fourth feature value is ,in, , and Each to their own satisfaction: , , , , , and The following conditions must be met: , .

10. The energy storage battery equalization control method according to claim 9, characterized in that, satisfy: .

11. The energy storage battery equalization control method according to claim 1, characterized in that, After completing the equalization control for the target energy storage battery, all equalization priority indicators are updated, and based on all updated equalization priority indicators, target energy storage batteries participating in the equalization control are iteratively selected until the equalization control of all candidate energy storage batteries is completed. The energy storage battery equalization control method further includes: Obtain the correlation feature value between the voltage and state of charge of the target energy storage battery; If the detected associated feature value is greater than or equal to a preset associated feature value threshold, voltage equalization control and capacity equalization control are performed on the target energy storage battery. If the associated feature value is detected to be less than the preset associated feature value threshold, capacity equalization control is performed on the target energy storage battery.

12. The energy storage battery equalization control method according to claim 11, characterized in that, The energy storage battery equalization control method also includes: During the process of performing capacity equalization control on the target energy storage battery, the real-time state of charge value of the target energy storage battery and the state of charge reference value of the energy storage system are obtained. The state of charge deviation value of the target energy storage battery is determined based on the real-time state of charge value and the state of charge reference value. If the detected state of charge deviation value is less than or equal to a preset state of charge deviation value threshold, capacity equalization control of the target energy storage battery is stopped.

13. A battery equalization control device for energy storage, characterized in that, The energy storage battery balancing control device, applied to energy storage systems, includes: The acquisition module is used to acquire the balance priority index corresponding to each of the multiple candidate energy storage batteries that meet the balance control conditions in the energy storage system. The balance priority index represents the balance priority of the candidate energy storage battery after being affected by operational risk characteristic information. The operational risk characteristic information includes at least two of the following: voltage deviation risk information, capacity health risk information, operational status risk information, and thermal correlation risk information. The balance priority index is calculated by the operational risk characteristic value and characteristic value weight determined by the energy storage system during real-time operation. The operational risk characteristic value includes at least two of the following: a first operational risk characteristic value after being affected by the voltage deviation risk information, a second operational risk characteristic value after being affected by the capacity health risk information, a third operational risk characteristic value after being affected by the operational status risk information, and a fourth operational risk characteristic value after being affected by the thermal correlation risk information. The characteristic value weight includes at least two of the following: a first characteristic value weight corresponding to the first operational risk characteristic value, a second characteristic value weight corresponding to the second operational risk characteristic value, a third characteristic value weight corresponding to the third operational risk characteristic value, and a fourth characteristic value weight corresponding to the fourth operational risk characteristic value. The selection module is used to select the target energy storage battery to participate in the balance control from the plurality of candidate energy storage batteries based on all balance priority indicators. The equalization control module is used to update all equalization priority indicators after equalization control is completed for the target energy storage battery, and iteratively select target energy storage batteries to participate in equalization control based on all updated equalization priority indicators, until equalization control of all candidate energy storage batteries is completed; wherein, The first operational risk feature value is calculated by fusing voltage deviation feature value, equalization control voltage difference threshold, and equalization stop voltage difference threshold. The weight of the first feature value is obtained by correcting the weight of the first basic feature value using voltage change feature value. The second operational risk feature value is calculated by fusing state of charge deviation feature value, equalization control state of charge difference threshold, and equalization stop state of charge difference threshold. The weight of the second feature value is obtained by correcting the weight of the second basic feature value using state of charge difference feature value, first feature value, second feature value, and state of charge confidence. The third operational risk feature value is obtained by querying state of charge identifier. The weight of the third feature value is obtained by dynamically correcting the weight of the third basic feature value based on state of charge confidence. The fourth operational risk feature value is obtained by jointly determining real-time health, temperature deviation value, and actual temperature value. The weight of the fourth feature value is obtained by dynamically correcting the weight of the fourth basic feature value based on real-time health.

14. An energy storage system comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the energy storage battery equalization control method as described in any one of claims 1 to 12.

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