Energy storage system and control method therefor

Abstract

An energy storage system and a control method therefor. The energy storage system comprises a plurality of battery cluster systems. The control method comprises: determining the number of overcurrent battery clusters in a plurality of battery cluster systems (S101); on the basis of a preset current distribution strategy, by means of the number of overcurrent battery clusters, determining a current distribution rule for the plurality of battery cluster systems (S102); and according to the determined current distribution rule, determining target current output values respectively corresponding to the plurality of battery cluster systems, so that each battery cluster system outputs electrical energy according to the corresponding target current output value (S103). The technical problem in the prior art that battery cluster systems do not supply power to the outside according to optimal current output values is solved, and the technical effects of preventing the battery cluster systems from generating overcurrent and improving the power supply efficiency of energy storage systems are achieved.

Description

Energy storage system and control method thereof

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority to Chinese patent application number 202410184202X, filed with the Chinese Patent Office on February 19, 2024, entitled “A Energy Storage System and Its Control Method,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the field of energy storage technology, and in particular to an energy storage system and a control method thereof. Background Art

[0004] In existing technology, the battery management system (BMS) changes the current output of each battery cluster system based on control signals from the energy management system (EMS). This causes the DC-DC converter (DCDC) in each battery cluster system to output different current values ​​to the DC bus. Consequently, the battery cluster system only outputs the maximum current allowed by the system within the safety range, without considering how to optimize the output current value, which affects the efficiency of the energy storage system.

[0005] Summary of the Invention

[0006] The problem to be solved by the present disclosure is that the battery cluster system in the prior art does not supply power to the outside according to the optimal current output value, which affects the working efficiency of the energy storage system.

[0007] In order to overcome the above-mentioned deficiencies in the prior art, the present disclosure aims to provide a control method for an energy storage system, wherein the energy storage system includes a plurality of battery cluster systems, and the control method includes:

[0008] determining the number of overcurrent battery clusters in the plurality of battery cluster systems;

[0009] Based on a preset current distribution strategy, and according to the number of overcurrent battery clusters, a current distribution rule for the plurality of battery cluster systems is determined;

[0010] According to the determined current distribution rule, target current output values ​​corresponding to the plurality of battery cluster systems are determined, so that each battery cluster system outputs electric energy according to the corresponding target current output value.

[0011] Furthermore, in the above method, the number of overcurrent battery clusters in the plurality of battery cluster systems is determined by:

[0012] Obtain predicted current output values ​​and preset maximum current output values ​​corresponding to multiple battery cluster systems, wherein the predicted current output values ​​include:

[0013] The preset maximum current output value is determined according to the current distribution ratio corresponding to each battery cluster system and the total current output value of the multiple battery cluster systems. The preset maximum current output value is determined by the state of charge and temperature corresponding to each battery cluster system.

[0014] For each battery cluster system, whether the battery cluster system is an overcurrent battery cluster system is determined based on a comparison result between the predicted current output value of the battery cluster system and the preset maximum current output value, so as to count the number of overcurrent battery clusters in the multiple battery cluster systems.

[0015] Furthermore, in the above method, the current distribution rule includes a current optimization rule for optimizing the output power of each battery cluster system and an overcurrent regulation rule for preventing each battery cluster system from generating an overcurrent phenomenon.

[0016] Furthermore, in the above method, the current distribution rules for the multiple battery cluster systems are determined in the following manner:

[0017] Determining whether the number of overcurrent battery clusters is zero;

[0018] When the number of the overcurrent battery clusters is zero, the current distribution rule is determined to be the current optimization rule, wherein the current optimization rule is to use the predicted current output value corresponding to each battery cluster system as the target current output value;

[0019] When the number of the overcurrent battery clusters is not zero, the overcurrent regulation rules for the multiple battery cluster systems are determined according to the number of the overcurrent battery clusters and the maximum overcurrent amplitude in the overcurrent battery cluster system.

[0020] Furthermore, in the above method, the overcurrent battery cluster system includes at least one, and the maximum overcurrent amplitude is calculated by the following method:

[0021] For each overcurrent battery cluster system, the difference between the predicted current output value corresponding to the overcurrent battery cluster system and the preset maximum current output value is compared with the preset maximum current output value to obtain the overcurrent amplitude of the overcurrent battery cluster system, so as to determine the maximum overcurrent amplitude in at least one overcurrent battery cluster system.

[0022] Furthermore, in the above method, the overcurrent regulation rules for the multiple battery cluster systems are determined in the following manner:

[0023] Determining a first comparison result between the number of overcurrent battery clusters and a preset number of overcurrent battery clusters, and determining a second comparison result between the maximum overcurrent amplitude and a preset overcurrent amplitude;

[0024] An overcurrent regulation rule for the plurality of battery cluster systems is determined according to the first comparison result and the second comparison result.

[0025] Furthermore, in the above method, the overcurrent regulation rule includes: determining a target current output value of each battery cluster system according to a preset current regulation value corresponding to the determined overcurrent regulation rule.

[0026] Furthermore, in the above method, the overcurrent regulation rule includes:

[0027] A first allocation rule corresponding to when the maximum overcurrent amplitude is less than or equal to a preset overcurrent amplitude, wherein the first allocation rule includes: adjusting the total current output value of the multiple battery cluster systems by a preset current adjustment value corresponding to the first allocation rule, and determining the target current output value of each battery cluster system according to the adjusted total current output value, so that the target current output value of each battery cluster system is less than or equal to the preset maximum current output value.

[0028] Furthermore, in the above method, the preset current adjustment value corresponding to the first allocation rule is the maximum overcurrent amplitude, and the step of determining the target current output values ​​corresponding to the plurality of battery cluster systems respectively according to the first allocation rule includes:

[0029] predicting a target total current output value of the plurality of battery cluster systems based on the maximum overcurrent amplitude and the total current output value of the plurality of battery cluster systems;

[0030] For each battery cluster system, the product of the target total current output value and the current distribution ratio corresponding to the battery cluster system is used as the target current output value of the battery cluster system.

[0031] Furthermore, in the above method, the overcurrent regulation rule includes:

[0032] The second allocation rule corresponding to when the number of overcurrent battery clusters is less than or equal to the preset number of overcurrent battery clusters and the maximum overcurrent amplitude is greater than the preset overcurrent amplitude, wherein the second allocation rule includes: determining the target current output value of each battery cluster system according to the preset current adjustment values ​​corresponding to the overcurrent battery cluster system and other battery cluster systems except the overcurrent battery cluster system.

[0033] Furthermore, in the above method, the preset current adjustment value corresponding to the second allocation rule includes:

[0034] The step of determining the target current output values ​​corresponding to the multiple battery cluster systems respectively according to the second allocation rule based on the preset maximum current output value corresponding to the overcurrent battery cluster system and the predicted current output values ​​corresponding to the other battery cluster systems includes: using the preset maximum current output value corresponding to the overcurrent battery cluster system as the target current output value of the overcurrent battery cluster system, and using the predicted current output values ​​corresponding to the other battery cluster systems except the overcurrent battery cluster system as the target current output values ​​of the other battery cluster systems.

[0035] Furthermore, in the above method, the overcurrent regulation rule includes:

[0036] A third allocation rule corresponding to when the number of overcurrent battery clusters is greater than the preset number of overcurrent battery clusters and the maximum overcurrent amplitude is greater than the preset overcurrent amplitude, wherein the third allocation rule includes: determining the target current output value of each battery cluster system according to the preset current adjustment value corresponding to each battery cluster system.

[0037] Furthermore, in the above method, the preset current adjustment value corresponding to the third allocation rule includes a preset maximum current output value. The step of determining the target current output values ​​corresponding to the multiple battery cluster systems respectively according to the third allocation rule includes: using the preset maximum current output value corresponding to each battery cluster system as the target current output value of each battery cluster system.

[0038] Furthermore, in the above method, the energy storage system further includes an energy management system and a display, and determining the target current output values ​​corresponding to the multiple battery cluster systems respectively according to the determined current distribution rule includes:

[0039] sending a rule identification signal to the energy management system so that a user can view the determined current distribution rule through the display and sending a control signal for a plurality of battery cluster systems, the control signal being used to indicate a target current output value corresponding to each battery cluster system;

[0040] Each battery cluster system is controlled according to the control signal to output electric energy according to the corresponding target current output value.

[0041] Another object of the present disclosure is to provide an energy storage system, which includes multiple battery cluster systems and a battery management system, and the battery management system is used to execute the steps of the energy storage system control method described in the first aspect or any possible implementation of the first aspect.

[0042] Furthermore, in the above system, the energy storage system also includes a DC bus, wherein each battery cluster system is connected to the DC bus, and the current value on the DC bus is the total current output value of the multiple battery cluster systems. For each battery cluster system, the battery cluster system includes a battery cluster and a DC converter, and the DC converter is arranged between the battery cluster and the DC bus, and the DC converter is used to transmit the electrical energy of the battery cluster to the DC bus.

[0043] Furthermore, in the above system, the energy storage system also includes an energy management system and a display, wherein the battery management system is used to send a rule identification signal to the energy management system; the display is used to display the current distribution rule corresponding to the rule identification signal, so that the user can view the current distribution rule through the display and send control signals for multiple battery cluster systems, and the control signal is used to indicate the target current output value corresponding to each battery cluster system; the energy management system is used to send the control signal to the battery management system; the battery management system is used to control each battery cluster system to output electrical energy according to the corresponding target current output value according to the control signal.

[0044] Another object of the present disclosure is to provide a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, executes the steps of the method for controlling an energy storage system described in the first aspect or any possible implementation of the first aspect.

[0045] An energy storage system and control method thereof are provided in an embodiment of the present disclosure. The energy storage system includes multiple battery cluster systems, and the control method includes: determining the number of overcurrent battery clusters in the multiple battery cluster systems; based on a preset current distribution strategy, determining a current distribution rule for the multiple battery cluster systems using the number of overcurrent battery clusters; and determining target current output values ​​corresponding to the multiple battery cluster systems according to the determined current distribution rule, so that each battery cluster system outputs electrical energy according to the corresponding target current output value. The current distribution rule for adjusting the current output value of each battery cluster system is determined by determining whether each battery cluster system in the energy storage system has an overcurrent phenomenon. After adjustment according to the current distribution rule, the current output value of each battery cluster system is optimized, thereby solving the technical problem in the prior art that the battery cluster system does not supply power to the outside according to the optimal current output value, and achieving the technical effect of preventing the battery cluster system from generating overcurrent and improving the power supply efficiency of the energy storage system.

[0046] The beneficial effects of other technical solutions in the above technical solutions will be described in detail in the subsequent specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] FIG1 shows a flow chart of a method for controlling an energy storage system provided by an embodiment of the present disclosure.

[0048] FIG2 shows a flow chart of another method for controlling an energy storage system provided by an embodiment of the present disclosure.

[0049] FIG3 is a schematic diagram showing the effect of adjustment according to the current distribution rule provided by an embodiment of the present disclosure.

[0050] FIG4 shows a schematic structural diagram of an energy storage system provided by an embodiment of the present disclosure. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solutions and advantages of the embodiments of the present disclosure clearer, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. It should be understood that the drawings in the present disclosure are only for the purpose of illustration and description and are not used to limit the scope of protection of the present disclosure. In addition, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in the present disclosure illustrate operations implemented according to some embodiments of the present disclosure. It should be understood that the operations of the flowchart can be implemented out of sequence, and steps that do not have a logical context relationship can be reversed in order or implemented simultaneously. In addition, those skilled in the art, guided by the contents of the present disclosure, can add one or more other operations to the flowchart, or remove one or more operations from the flowchart.

[0052] In addition, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. The components of the embodiments of the present disclosure generally described and shown in the drawings herein can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present disclosure provided in the drawings is not intended to limit the scope of the disclosure claimed for protection, but merely represents selected embodiments of the present disclosure. Based on the embodiments of the present disclosure, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present disclosure.

[0053] In existing technologies, the maximum power output of each battery cluster system is only controlled as a safety boundary condition. The output power that meets safety requirements does not necessarily correspond to the output power required to optimize the energy storage system's performance. Furthermore, this merely limits the maximum power output of each battery cluster system, failing to achieve an optimal distribution of output power across the cluster systems.

[0054] Based on this, embodiments of the present disclosure provide an energy storage system and a control method thereof. Current distribution rules for adjusting the current output values ​​of each battery cluster system are determined by determining whether each battery cluster system in the energy storage system has an overcurrent phenomenon. Adjustments are made according to the current distribution rules to optimize the current output values ​​of each battery cluster system. This solves the technical problem in the prior art where the battery cluster system does not supply power to the outside at the optimal current output value, achieving the technical effects of preventing overcurrent phenomena in the battery cluster system and improving the power supply efficiency of the energy storage system. The details are as follows:

[0055] Please refer to Figure 1, which is a flow chart of a control method for an energy storage system provided by an embodiment of the present disclosure. As shown in Figure 1, the control method for an energy storage system provided by an embodiment of the present disclosure includes multiple battery cluster systems. The control method is applied to a battery management system and includes the following steps:

[0056] S101: Determine the number of overcurrent battery clusters in the plurality of battery cluster systems.

[0057] Specifically, for each battery cluster system, a determination is made as to whether the battery cluster system is an overcurrent battery cluster system, and the number of overcurrent battery cluster systems is counted. Alternatively, if the battery management system has not received a command for full-power operation, the number of overcurrent battery clusters in the multiple battery cluster systems is determined. Full-power operation refers to controlling each battery cluster system to output electrical energy according to its corresponding preset maximum current output value. Furthermore, while output power requirements are met, the output current is distributed among the battery cluster systems based on the number of overcurrent battery clusters, thereby optimizing power distribution.

[0058] The number of overcurrent battery clusters in the multiple battery cluster systems is determined in the following manner: predicted current output values ​​and preset maximum current output values ​​corresponding to the multiple battery cluster systems are obtained, the predicted current output value including: a current distribution ratio corresponding to each battery cluster system and a total current output value of the multiple battery cluster systems, and the preset maximum current output value refers to a value determined by the state of charge and temperature corresponding to each battery cluster system; for each battery cluster system, whether the battery cluster system is an overcurrent battery cluster system is determined based on a comparison result between the predicted current output value of the battery cluster system and the preset maximum current output value, so as to count the number of overcurrent battery clusters in the multiple battery cluster systems.

[0059] Specifically, the predicted current output value is not the actual current output value of the battery cluster system, but the current distribution ratio corresponding to each battery cluster system is calculated according to the capacity consistency. The predicted current output value of each battery cluster system is obtained by multiplying the current distribution ratio corresponding to each battery cluster system by the total current output value.

[0060] The calculation method of the current distribution ratio is conventional and will not be described in detail here. The total current output value refers to the sum of the actual current output values ​​of each battery cluster system.

[0061] Specifically, the preset maximum current output value is determined by searching a preset current limit table based on the state of charge and temperature of each battery cluster system. In other words, the preset current limit table includes the preset maximum current output values ​​corresponding to different states of charge and temperatures. By searching the preset current limit table, the preset maximum current output value corresponding to the state of charge and temperature of each battery cluster system is determined.

[0062] Furthermore, for each battery cluster system, it is determined whether the predicted current output value of the battery cluster system is greater than the preset maximum current output value; if the predicted current output value of the battery cluster system is greater than the preset maximum current output value, then the battery cluster system is an overcurrent battery cluster system, that is, the battery cluster system produces an overcurrent phenomenon; if the predicted current output value of the battery cluster system is less than or equal to the preset maximum current output value, then the battery cluster system is not an overcurrent battery cluster system, thereby counting the number of overcurrent battery clusters in the multiple battery cluster systems.

[0063] S102: Based on a preset current distribution strategy and the number of overcurrent battery clusters, determine a current distribution rule for the plurality of battery cluster systems.

[0064] The current distribution rules include current optimization rules for optimizing the output power of each battery cluster system and overcurrent regulation rules for preventing overcurrent in each battery cluster system. In other words, the current distribution rules are used to optimize the output power of each battery cluster system or to prevent overcurrent in each battery cluster system. The preset current distribution strategy refers to a pre-set current distribution strategy that determines the current distribution rule based on the number of overcurrent battery clusters.

[0065] The current distribution rules for the multiple battery cluster systems are determined in the following manner: determining whether the number of overcurrent battery clusters is zero; when the number of overcurrent battery clusters is zero, determining the current distribution rule as the current optimization rule, and the current optimization rule refers to using the predicted current output value corresponding to each battery cluster system as the target current output value to optimize the output power of each battery cluster system; when the number of overcurrent battery clusters is not zero, determining the overcurrent regulation rules for the multiple battery cluster systems based on the number of overcurrent battery clusters and the maximum overcurrent amplitude in the overcurrent battery cluster system to prevent overcurrent in each battery cluster system.

[0066] That is, if no overcurrent battery cluster system exists among the multiple battery cluster systems, the output power of the multiple battery cluster systems is optimized, and the predicted current output value corresponding to each battery cluster system is used as the target current output value. If an overcurrent battery cluster system exists among the multiple battery cluster systems, the current output value of the overcurrent battery cluster system or each battery cluster system is reduced to prevent overcurrent in the battery cluster system.

[0067] Specifically, the overcurrent battery cluster system includes at least one, and the maximum overcurrent amplitude is calculated in the following manner: for each overcurrent battery cluster system, the difference between the predicted current output value corresponding to the overcurrent battery cluster system and the preset maximum current output value is compared with the preset maximum current output value to obtain the overcurrent amplitude of the overcurrent battery cluster system, so as to determine the maximum overcurrent amplitude in at least one overcurrent battery cluster system.

[0068] That is, when there is an overcurrent battery cluster system among multiple battery cluster systems, the overcurrent battery cluster system includes at least one, and then, after calculating the overcurrent amplitude corresponding to each overcurrent battery cluster system, the largest overcurrent amplitude is determined among all the overcurrent battery cluster systems as the maximum overcurrent amplitude.

[0069] The overcurrent regulation rules for the multiple battery cluster systems are determined in the following manner: determining a first comparison result between the number of overcurrent battery clusters and a preset number of overcurrent battery clusters, and determining a second comparison result between the maximum overcurrent amplitude and a preset overcurrent amplitude; and determining the overcurrent regulation rules for the multiple battery cluster systems based on the first comparison result and the second comparison result.

[0070] The overcurrent regulation rule includes: determining the target current output value of each battery cluster system according to the preset current regulation value corresponding to the determined overcurrent regulation rule. In other words, different overcurrent regulation rules correspond to different preset current regulation values.

[0071] The overcurrent regulation rules include a first allocation rule corresponding to when the maximum overcurrent amplitude is less than or equal to a preset overcurrent amplitude, a second allocation rule corresponding to when the number of overcurrent battery clusters is less than or equal to the preset number of overcurrent battery clusters and the maximum overcurrent amplitude is greater than the preset overcurrent amplitude, and a third allocation rule corresponding to when the number of overcurrent battery clusters is greater than the preset number of overcurrent battery clusters and the maximum overcurrent amplitude is greater than the preset overcurrent amplitude.

[0072] The first allocation rule includes adjusting the total current output value of the multiple battery cluster systems using a preset current adjustment value corresponding to the first allocation rule, and determining a target current output value for each battery cluster system based on the adjusted total current output value, so that the target current output value of each battery cluster system is less than or equal to a preset maximum current output value. The second allocation rule includes determining the target current output value for each battery cluster system based on the preset current adjustment values ​​corresponding to the overcurrent battery cluster system and other battery cluster systems other than the overcurrent battery cluster system. The third allocation rule includes determining the target current output value for each battery cluster system based on the preset current adjustment value corresponding to each battery cluster system.

[0073] The preset current adjustment value corresponding to the first allocation rule is the maximum overcurrent amplitude. The step of determining the target current output values ​​corresponding to the multiple battery cluster systems respectively according to the first allocation rule includes: predicting the target total current output value of the multiple battery cluster systems based on the maximum overcurrent amplitude and the total current output value of the multiple battery cluster systems; and for each battery cluster system, taking the product of the target total current output value and the current allocation ratio corresponding to the battery cluster system as the target current output value of the battery cluster system.

[0074] That is, when the maximum overcurrent amplitude is less than or equal to the preset overcurrent amplitude, the predicted total current output value is first reduced and then multiplied by the current allocation ratio corresponding to each battery cluster system, thereby reducing the target current output value corresponding to each battery cluster system. Furthermore, the total current output value is derated by a factor of 1 based on the maximum overcurrent amplitude, so that the battery cluster system corresponding to the reduced maximum overcurrent amplitude can still output a current less than or equal to its preset maximum output value.

[0075] Specifically, the maximum overcurrent amplitude is calculated using the following formula:

[0076] In formula (1), max(Pct ex ) refers to the maximum overcurrent amplitude of all overcurrent battery cluster systems in the energy storage system, I bus0 Refers to the total current output value, I pct,j Refers to the current distribution ratio corresponding to the j-th overcurrent battery cluster system, SOP j Refers to the preset maximum current output value corresponding to the j-th overcurrent battery cluster system.

[0077] Specifically, the target total current output value of the multiple battery cluster systems is predicted by the following formula:

[0078] In formula (2), I bus,new Refers to the target total current output value, Ibus0 Refers to the total current output value, I pct,j Refers to the current distribution ratio corresponding to the j-th overcurrent battery cluster system, SOP j Refers to the preset maximum current output value corresponding to the jth overcurrent battery cluster system. pct,j ×I bus0 Refers to the predicted current output value corresponding to the j-th overcurrent battery cluster system.

[0079] The preset current adjustment value corresponding to the second allocation rule includes: a preset maximum current output value corresponding to the overcurrent battery cluster system and a predicted current output value corresponding to other battery cluster systems. The step of determining the target current output values ​​corresponding to the multiple battery cluster systems respectively according to the second allocation rule includes: using the preset maximum current output value corresponding to the overcurrent battery cluster system as the target current output value of the overcurrent battery cluster system, and using the predicted current output values ​​corresponding to the other battery cluster systems other than the overcurrent battery cluster system as the target current output values ​​of the other battery cluster systems.

[0080] The preset current adjustment value corresponding to the third allocation rule includes a preset maximum current output value. The step of determining the target current output values ​​corresponding to the multiple battery cluster systems respectively according to the third allocation rule includes: using the preset maximum current output value corresponding to each battery cluster system as the target current output value of each battery cluster system.

[0081] That is, it is determined whether the maximum overcurrent amplitude is greater than the preset overcurrent amplitude; when the maximum overcurrent amplitude is less than or equal to the preset overcurrent amplitude, the target current output value of each battery cluster system is determined by the maximum overcurrent amplitude, so that the target current output value of each battery cluster system is less than or equal to the corresponding preset maximum current output value; when the maximum overcurrent amplitude is greater than the preset overcurrent amplitude, it is determined whether the number of overcurrent battery clusters is greater than the preset number of overcurrent battery clusters; when the number of overcurrent battery clusters is less than or equal to the preset number of overcurrent battery clusters, the preset maximum current output value corresponding to the overcurrent battery cluster system is used as the target current output value of the overcurrent battery cluster system, and for other battery cluster systems other than the overcurrent battery cluster system, the predicted current output values ​​corresponding to the other battery cluster systems are used as the target current output values ​​of the other battery cluster systems; when the number of overcurrent battery clusters is greater than the preset number of overcurrent battery clusters, the preset maximum current output value corresponding to each battery cluster system is used as the target current output value of each battery cluster system.

[0082] For example, the preset overcurrent amplitude may be set to 10%, and the preset number of overcurrent battery clusters may be set to one third of the total number of battery cluster systems.

[0083] For example, please refer to FIG2 , which is a flow chart of another method for controlling an energy storage system provided by an embodiment of the present disclosure, as shown in FIG2 :

[0084] S201: Determine whether the number of overcurrent battery clusters in the plurality of battery cluster systems is zero.

[0085] S202 : Determine a target current output value corresponding to each battery cluster system according to a current distribution ratio corresponding to each battery cluster system and a total current output value of the plurality of battery cluster systems.

[0086] That is, if the number of overcurrent battery clusters in the multiple battery cluster systems is zero, the target current output value corresponding to each battery cluster system is determined according to the current distribution ratio corresponding to each battery cluster system and the total current output value of the multiple battery cluster systems.

[0087] For example, please refer to Figure 3, which is a schematic diagram of the effect of adjusting the current distribution rule according to the embodiment of the present disclosure. As shown in Figure 3, the horizontal axis refers to the number corresponding to each of the multiple battery cluster systems, and the vertical axis refers to the output power of each battery cluster system. When there is no overcurrent battery cluster, the output power curve of the battery cluster system 1. Original does not exceed the preset output power P limit After allocating the current according to the current distribution ratio corresponding to each battery cluster system and the total current output value, the updated output power curve 1.OPD of the battery cluster system is obtained, making the output power of the battery cluster system smoother.

[0088] S203: Determine whether the maximum overcurrent amplitude of the overcurrent battery cluster system is greater than a preset overcurrent amplitude.

[0089] That is, if the number of overcurrent battery clusters in the multiple battery cluster systems is not zero, the maximum overcurrent amplitude corresponding to at least one overcurrent battery cluster system is calculated to determine whether the maximum overcurrent amplitude is greater than a preset overcurrent amplitude.

[0090] S204: Determine a target current output value of each battery cluster system according to the maximum overcurrent amplitude.

[0091] That is, if the maximum overcurrent amplitude is less than or equal to the preset overcurrent amplitude, the target current output value of each battery cluster system is determined by reducing the total current output value by the maximum overcurrent amplitude.

[0092] S205: Determine whether the number of overcurrent battery clusters in the overcurrent battery cluster system is greater than a preset number of overcurrent battery clusters.

[0093] That is, if the maximum overcurrent amplitude is greater than the preset overcurrent amplitude, it is determined whether the number of overcurrent battery clusters in the overcurrent battery cluster system is greater than the preset number of overcurrent battery clusters.

[0094] S206: Using the preset maximum current output value corresponding to the overcurrent battery cluster system as the target current output value of the overcurrent battery cluster system and using the predicted current output values ​​of other battery cluster systems except the overcurrent battery cluster system as the target current output values ​​of other battery cluster systems.

[0095] That is to say, when the maximum overcurrent amplitude is greater than the preset overcurrent amplitude and the number of overcurrent battery clusters is less than or equal to the preset number of overcurrent battery clusters, the preset maximum current output value corresponding to the overcurrent battery cluster system is used as the target current output value of the overcurrent battery cluster system, and the predicted current output values ​​of the battery cluster systems other than the overcurrent battery cluster system are used as the target circuit output values ​​of the other battery cluster systems.

[0096] S207: Using the preset maximum current output value corresponding to each battery cluster system as the target current output value of each battery cluster system.

[0097] That is, when the maximum overcurrent amplitude is greater than the preset overcurrent amplitude and the number of overcurrent battery clusters is greater than the preset number of overcurrent battery clusters, the preset maximum current output value corresponding to each battery cluster system is used as the target current output value of each battery cluster system.

[0098] That is, when the maximum overcurrent amplitude is greater than the preset overcurrent amplitude and the number of overcurrent battery clusters is greater than the preset number of overcurrent battery clusters, each battery cluster system is directly set to operate at full power, thereby preventing each battery cluster system from generating overcurrent.

[0099] As shown in Figure 3, the battery cluster system's output power curve 2. Original refers to the output power curve when the number of overcurrent battery clusters is less than or equal to the preset number of overcurrent battery clusters and the maximum overcurrent amplitude of the overcurrent battery cluster system is greater than the preset overcurrent amplitude. The overcurrent battery cluster system outputs current according to the preset maximum current output value, while the remaining battery cluster systems output current according to the predicted current output values. This ensures that the updated output power curve 2. POPD of the battery cluster system is less than the preset output power, preventing overcurrent output of the battery cluster system. The output power curve 3. Original of the battery cluster system refers to the output power curve when the number of overcurrent battery clusters is greater than the preset number of overcurrent battery clusters and the maximum overcurrent amplitude of the overcurrent battery cluster system is less than the preset overcurrent amplitude. A new total current output value is calculated based on the maximum overcurrent amplitude and then allocated according to the corresponding proportions of each battery cluster system to determine the target current output value for each battery cluster system. This ensures that the updated output power curve 3. LPD of the battery cluster system is less than the preset output power, preventing overcurrent output of the battery cluster system.

[0100] Returning to FIG. 1 , S103 : determining target current output values ​​corresponding to the plurality of battery cluster systems respectively according to the determined current distribution rule, so that each battery cluster system outputs electric energy according to the corresponding target current output value.

[0101] The energy storage system also includes an energy management system and a display. Determining the target current output values ​​corresponding to the multiple battery cluster systems according to the determined current distribution rule includes: sending a rule identification signal to the energy management system so that a user can view the determined current distribution rule through the display and sending control signals for the multiple battery cluster systems, the control signal being used to indicate the target current output value corresponding to each battery cluster system; and controlling each battery cluster system to output electrical energy according to the corresponding target current output value based on the control signal.

[0102] That is to say, after determining that each battery cluster system outputs electrical energy according to the corresponding target current output value, the battery management system can directly control each system to output electrical energy according to the corresponding target current output value, or it can generate a rule identification signal according to the determined current distribution rule and send the rule identification signal to the display so that the user can confirm the determined current distribution rule, so that the user can determine whether to control each battery cluster system to output electrical energy according to the corresponding target current output value according to the current distribution rule. Furthermore, the user can inform the energy management system of the target current output value of each battery cluster system by operating the display screen, so that the energy management system can generate a control signal according to the target current output value, so that the battery management system can control each battery cluster system to output electrical energy according to the corresponding target current output value according to the control signal.

[0103] That is, the control signal may be a target current output value of each battery cluster system determined according to the current distribution rule, or may be a signal set by the user to indicate the target current output value of each battery cluster system.

[0104] For example, when the current distribution rule is the current optimization rule, the rule identification signal sent to the energy management system is OPD_flg=1, where OPD refers to Optimal Power Distribution, and then the energy management system is informed that it is recommended to distribute the output current value of a single battery cluster system according to the current distribution ratio corresponding to each battery cluster system and the total current output value of multiple battery cluster systems, and the output current value will not exceed the corresponding preset maximum current output value; when the current distribution rule is the first distribution rule, the rule identification signal sent to the energy management system is LPD_flg=1, where LPD refers to Limited Power Distribution, and then inform the energy management system to recommend that the total current output value be derated and then distributed according to the current distribution ratio corresponding to each battery cluster system, and the rule identification signal can also be divided into HLPD_flg=1 or LLPD_flg=1 according to the comparison result of the number of overcurrent battery clusters and the preset number of overcurrent battery clusters, wherein, when the number of overcurrent battery clusters is less than or equal to the preset number of overcurrent battery clusters and the maximum overcurrent amplitude is less than or equal to the preset overcurrent amplitude, the rule identification signal is divided into LLPD_flg=1, and when the number of overcurrent battery clusters is greater than the preset number of overcurrent battery clusters and the maximum overcurrent amplitude is less than or equal to the preset overcurrent amplitude, the rule identification signal is divided into HLPD_flg=1; when the current distribution rule is the second distribution rule, the rule identification signal sent to the energy management system is POPD_flg=1, wherein POPD refers to Partial Optimal Power Distribution, tells the energy management system to recommend that the overcurrent battery cluster system output current according to the preset maximum current output value, and the remaining battery cluster systems output current according to the predicted current output value; when the current distribution rule is the third distribution rule, the rule identification signal FPD_flg=1 is sent to the energy management system, where FPD refers to Full Power Distribution, which tells the energy management system to recommend that the current be output according to the preset maximum current output value corresponding to each battery cluster system, that is, to output current according to the full power operation mode.

[0105] Furthermore, through the above embodiments, the control method disclosed herein can be applied to different scenarios and controlled within the maximum allowable output current value to achieve reasonable distribution and control of the power of the energy storage system, thereby maximizing the available energy of the energy storage system while ensuring a safe range.

[0106] Based on the same application concept, the embodiments of the present disclosure also provide an energy storage system corresponding to the control method of the energy storage system provided in the above embodiments. Since the principle of solving the problem by the energy storage system in the embodiments of the present disclosure is similar to the control method of the energy storage system in the above embodiments of the present disclosure, the implementation of the energy storage system can refer to the implementation of the method, and the repeated parts will not be repeated.

[0107] As shown in Figure 4, Figure 4 is a structural schematic diagram of an energy storage system provided by an embodiment of the present disclosure. The energy storage system includes multiple battery cluster systems 101 and a battery management system BMS. The battery management system is used to execute the steps of the energy storage system control method provided by the above embodiment. The multiple battery cluster systems are connected to the battery management system so that the battery management system controls the multiple battery cluster systems to output electrical energy according to corresponding target current output values.

[0108] The energy storage system also includes a DC bus BUS, wherein each battery cluster system is connected to the DC bus, and the current value on the DC bus is the total current output value of the multiple battery cluster systems. For each battery cluster system 101, the battery cluster system includes a battery cluster 1011 and a DC converter 1012. The DC converter is arranged between the battery cluster and the DC bus, and is used to transmit the electrical energy of the battery cluster to the DC bus. Specifically, the DC converter is used to boost the voltage output by the battery cluster and transmit it to the DC bus.

[0109] The energy storage system also includes an energy management system and a display, wherein the battery management system is used to send a rule identification signal to the energy management system; the display is used to display the current distribution rule corresponding to the rule identification signal, so that a user can view the current distribution rule through the display and send control signals for multiple battery cluster systems, the control signal is used to indicate the target current output value corresponding to each battery cluster system; the energy management system is used to send the control signal to the battery management system; the battery management system is used to control each battery cluster system to output electrical energy according to the corresponding target current output value based on the control signal.

[0110] The control signal may be a user confirmation to perform control through a current distribution rule, or a user directly indicating an output current value of each battery cluster system.

[0111] That is to say, the battery management system generates a corresponding rule identification signal based on the current distribution rule determined by the number of overcurrent battery clusters, so that the energy management system displays the current distribution rule on the display screen through the rule identification signal, so that the user can confirm whether to use the current distribution rule determined by the battery management system and issue a control instruction to the energy management system through the display screen, so that the energy management system generates a control signal based on the control instruction issued by the user and sends the control signal to the battery management system, so that the battery management system controls each battery cluster system to output electrical energy according to the standard current output value corresponding to the control signal.

[0112] For example, the energy management system sends a control instruction FPD=1 for full-power operation to the battery management system, and the battery management system controls each battery cluster system to output current values ​​according to the corresponding preset maximum current output values, and the battery management system reports a feedback signal FPD_flg=1 to the energy management system to indicate that electric energy has been output in full-power operation; when the energy management system sends a control instruction FPD=0 for default operation to the battery management system, the battery management system defaults to operating by dividing the total output current value by the number of battery cluster systems and the minimum value of the preset maximum current output value of the battery cluster system, and reports a feedback signal DFPD_flg=1 to the energy management system to indicate that electric energy has been output in the default operation mode.

[0113] The present disclosure proposes a power control strategy that takes current limiting into consideration. When no full-power operation instruction is received, the current distribution strategy is determined by the number of overcurrent modules to indicate the current optimal operating state and an instruction for marking the current distribution strategy is given so that the system can operate according to the corresponding state after receiving an external instruction.

[0114] The present disclosure ensures the overall maximum power operation capability of the system, and takes into account the current limiting strategy under maximum energy, greatly improving the system life, charging and discharging efficiency, depth and consistency within the maximum power allowable range.

[0115] Based on the same application concept, an embodiment of the present disclosure further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the energy storage system control method provided in the above embodiment are executed.

[0116] Specifically, the storage medium can be a general storage medium, such as a mobile disk, a hard disk, etc. When the computer program on the storage medium is run, it can execute the above-mentioned energy storage system control method, and determine the current distribution rules for adjusting the current output values ​​of each battery cluster system by whether each battery cluster system in the energy storage system has an overcurrent phenomenon. After adjustment according to the current distribution rules, the current output value of each battery cluster system is optimized, thereby solving the technical problem in the prior art that the battery cluster system does not supply power to the outside according to the optimal current output value, and achieving the technical effect of preventing the battery cluster system from generating an overcurrent phenomenon and improving the power supply efficiency of the energy storage system.

[0117] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system and device described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. In the several embodiments provided in the present disclosure, it should be understood that the disclosed system, device and method can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0118] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0119] In addition, each functional unit in each embodiment of the present disclosure may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0120] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present disclosure, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present disclosure. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0121] The above are only specific embodiments of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that can be easily conceived by any person skilled in the art within the technical scope disclosed in this disclosure should be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims. Industrial Applicability:

[0122] The present disclosure provides an energy storage system and control method thereof. Current distribution rules for adjusting the current output values ​​of each battery cluster system are determined by determining whether each battery cluster system in the energy storage system has an overcurrent phenomenon. Adjustments are made according to the current distribution rules to optimize the current output values ​​of each battery cluster system. This solves the technical problem in the prior art where battery cluster systems fail to supply power to the outside at the optimal current output value, achieving the technical effect of preventing overcurrent phenomena in the battery cluster system and improving the power supply efficiency of the energy storage system.

Claims

1. A control method for an energy storage system, characterized in that: The energy storage system includes multiple battery cluster systems, and the control method includes: determining the number of overcurrent battery clusters in the plurality of battery cluster systems; Based on a preset current distribution strategy, and according to the number of overcurrent battery clusters, a current distribution rule for the plurality of battery cluster systems is determined; According to the determined current distribution rule, target current output values ​​corresponding to the plurality of battery cluster systems are determined, so that each battery cluster system outputs electric energy according to the corresponding target current output value.

2. The control method according to claim 1, characterized in that: The number of overcurrent battery clusters in the plurality of battery cluster systems is determined by: Obtaining predicted current output values ​​and preset maximum current output values ​​corresponding to each of the multiple battery cluster systems, wherein the predicted current output value is determined according to a current distribution ratio corresponding to each battery cluster system and a total current output value of the multiple battery cluster systems, and the preset maximum current output value is determined according to a state of charge and a temperature corresponding to each battery cluster system; For each battery cluster system, whether the battery cluster system is an overcurrent battery cluster system is determined based on a comparison result between the predicted current output value of the battery cluster system and the preset maximum current output value, so as to count the number of overcurrent battery clusters in the multiple battery cluster systems.

3. The control method according to claim 1, wherein: The current distribution rules include a current optimization rule for optimizing the output power of each battery cluster system and an overcurrent regulation rule for preventing each battery cluster system from generating an overcurrent phenomenon.

4. The control method according to claim 3, characterized in that: The current distribution rules for the multiple battery cluster systems are determined in the following manner: Determining whether the number of overcurrent battery clusters is zero; When the number of the overcurrent battery clusters is zero, the current distribution rule is determined to be the current optimization rule, wherein the current optimization rule is to use the predicted current output value corresponding to each battery cluster system as the target current output value; When the number of the overcurrent battery clusters is not zero, the overcurrent regulation rules for the multiple battery cluster systems are determined according to the number of the overcurrent battery clusters and the maximum overcurrent amplitude in the overcurrent battery cluster system.

5. The control method according to claim 4, characterized in that: The overcurrent battery cluster system includes at least one, and the maximum overcurrent amplitude is calculated in the following manner: For each overcurrent battery cluster system, the difference between the predicted current output value corresponding to the overcurrent battery cluster system and the preset maximum current output value is compared with the preset maximum current output value to obtain the overcurrent amplitude of the overcurrent battery cluster system, so as to determine the maximum overcurrent amplitude in at least one overcurrent battery cluster system.

6. The control method according to claim 4, characterized in that: The overcurrent regulation rules for the multiple battery cluster systems are determined in the following manner: Determining a first comparison result between the number of overcurrent battery clusters and a preset number of overcurrent battery clusters, and determining a second comparison result between the maximum overcurrent amplitude and a preset overcurrent amplitude; An overcurrent regulation rule for the plurality of battery cluster systems is determined according to the first comparison result and the second comparison result.

7. The control method according to claim 6, characterized in that: The overcurrent regulation rule includes: determining a target current output value of each battery cluster system according to a preset current regulation value corresponding to the determined overcurrent regulation rule.

8. The control method according to claim 7, characterized in that: The overcurrent regulation rule includes: a first allocation rule corresponding to when the maximum overcurrent amplitude is less than or equal to a preset overcurrent amplitude, Among them, the first allocation rule includes: adjusting the total current output value of the multiple battery cluster systems by a preset current adjustment value corresponding to the first allocation rule, and determining the target current output value of each battery cluster system according to the adjusted total current output value, so that the target current output value of each battery cluster system is less than or equal to a preset maximum current output value.

9. The control method according to claim 8, characterized in that: The preset current adjustment value corresponding to the first allocation rule is the maximum overcurrent amplitude, and the step of determining the target current output values ​​corresponding to the plurality of battery cluster systems respectively according to the first allocation rule includes: predicting a target total current output value of the plurality of battery cluster systems based on the maximum overcurrent amplitude and the total current output value of the plurality of battery cluster systems; For each battery cluster system, the product of the target total current output value and the current distribution ratio corresponding to the battery cluster system is used as the target current output value of the battery cluster system.

10. The control method according to claim 7, characterized in that: The overcurrent regulation rule includes: a second allocation rule corresponding to when the number of overcurrent battery clusters is less than or equal to the preset number of overcurrent battery clusters and the maximum overcurrent amplitude is greater than the preset overcurrent amplitude, The second allocation rule includes determining a target current output value of each battery cluster system according to preset current adjustment values ​​corresponding to the overcurrent battery cluster system and other battery cluster systems except the overcurrent battery cluster system.

11. The control method according to claim 10, characterized in that: The preset current adjustment value corresponding to the second allocation rule includes: a preset maximum current output value corresponding to the overcurrent battery cluster system and a predicted current output value corresponding to other battery cluster systems. The step of determining target current output values ​​corresponding to the plurality of battery cluster systems respectively according to the second allocation rule includes: The preset maximum current output value corresponding to the overcurrent battery cluster system is used as the target current output value of the overcurrent battery cluster system. The predicted current output values ​​corresponding to the battery cluster systems other than the overcurrent battery cluster system are used as target current output values ​​of the other battery cluster systems.

12. The control method according to claim 7, characterized in that: The overcurrent regulation rule includes: a third allocation rule corresponding to when the number of overcurrent battery clusters is greater than the preset number of overcurrent battery clusters and the maximum overcurrent amplitude is greater than the preset overcurrent amplitude, The third allocation rule includes: determining a target current output value of each battery cluster system according to a preset current adjustment value corresponding to each battery cluster system.

13. The control method according to claim 12, characterized in that: The preset current adjustment value corresponding to the third allocation rule includes a preset maximum current output value, The step of determining target current output values ​​corresponding to the plurality of battery cluster systems respectively according to the third allocation rule includes: The preset maximum current output value corresponding to each battery cluster system is used as the target current output value of each battery cluster system.

14. The control method according to claim 1, characterized in that: The energy storage system further includes an energy management system and a display. The determining of target current output values ​​corresponding to the plurality of battery cluster systems according to the determined current distribution rule includes: sending a rule identification signal to the energy management system so that a user can view the determined current distribution rule through the display and sending a control signal for a plurality of battery cluster systems, the control signal being used to indicate a target current output value corresponding to each battery cluster system; Each battery cluster system is controlled according to the control signal to output electric energy according to the corresponding target current output value.

15. An energy storage system, characterized in that: The energy storage system includes a plurality of battery cluster systems and a battery management system, and the battery management system is configured to execute the steps of the energy storage system control method according to any one of claims 1 to 14.

16. The energy storage system according to claim 15, characterized in that: The energy storage system further includes a DC bus, wherein each battery cluster system is connected to the DC bus, and the current value on the DC bus is the total current output value of the multiple battery cluster systems. Each battery cluster system includes a battery cluster and a DC converter. The DC converter is disposed between the battery cluster and the DC bus. The DC converter is used to transmit electrical energy from the battery cluster to the DC bus.

17. The energy storage system according to claim 15, characterized in that: The energy storage system also includes an energy management system and a display. Wherein, the battery management system is used to send a rule identification signal to the energy management system; The display is used to display the current distribution rule corresponding to the rule identification signal, so that a user can view the current distribution rule through the display and send control signals for multiple battery cluster systems, wherein the control signals are used to indicate the target current output value corresponding to each battery cluster system; The energy management system is used to send the control signal to the battery management system; The battery management system is used to control each battery cluster system to output electric energy according to a corresponding target current output value according to the control signal.

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