Power allocation method, energy management system, and storage medium

Abstract

The application belongs to the technical field of energy storage systems, and relates to a power distribution method, an energy management system and a storage medium. When the system state is charging or discharging, if the total system power meets the second power constraint condition and the first power constraint condition, the power of each battery pack is adjusted according to the equal state of charge distribution strategy; when the total system power does not meet the second power constraint condition but meets the first power constraint condition, the maximum allowable power limit amplification strategy is adopted to fully release the power potential and not exceed the safety range; when the first power constraint condition is not met, the equal current distribution strategy is adopted to avoid single pack overcurrent, improve system stability, safety and cell life. In addition, when the system state is idle, the maximum allowable power proportional distribution strategy is selected for power distribution. Based on this, the balance between battery packs and system power output is considered, and the use performance and operation stability of the energy storage system are improved.

Description

Power distribution methods, energy management systems and storage media Technical Field

[0001] This application belongs to the field of energy storage system technology, specifically relating to a power distribution method, an energy management system, and a storage medium. Background Technology

[0002] As energy storage systems continue to expand in scale, parallel connection of battery packs has become an important way to improve system capacity and power. Common solutions include direct parallel connection of batteries and parallel connection after boosting via bidirectional DC-DC converters. Direct parallel connection of batteries can easily induce circulating currents in actual operation, especially at low temperatures, which may lead to low-temperature circulating current charging and accelerated cell lifespan degradation. In contrast, battery packs equipped with bidirectional DC-DC converters are gradually becoming the mainstream application due to their voltage compatibility and operational independence.

[0003] In developing this application, the inventors discovered that existing energy storage systems equipped with bidirectional DC-DC battery packs still have shortcomings in power distribution. Existing methods mostly allocate power based on the charge and discharge limits of the battery packs, and stop operating after some battery packs are fully charged or discharged. This results in insufficient consideration of power balance between battery packs during operation, and a decrease in the overall power capacity of the system, potentially leading to excessively long charging times or premature loss of load-carrying capacity during discharge. Therefore, existing power distribution methods cannot simultaneously achieve balance between battery packs and system power output, impacting the performance and stability of the energy storage system. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a power distribution method that balances battery pack balancing with system power output, thereby improving the performance and operational stability of the energy storage system.

[0005] To address the aforementioned technical problems, one technical solution adopted in this application is: providing a power allocation method applied to an energy storage system, the method comprising: obtaining the total system power of the energy storage system; determining the system state of the energy storage system based on the total system power; selecting a first power allocation strategy when the system state is idle; selecting a second power allocation strategy when the system state is charging or discharging and the total system power does not meet the first power constraint condition; and selecting a third power allocation strategy when the system state is charging or discharging and the total system power meets the first power constraint condition, and if the total system power meets the second power constraint condition.

[0006] In some embodiments, when the system is in an idle state, selecting a first power allocation strategy includes: when the system is in an idle state, selecting a maximum allowable power ratio allocation strategy as the first power allocation strategy.

[0007] In some embodiments, when the system is in a charging state or a discharging state, and the total system power does not meet the first power constraint condition, selecting a second power allocation strategy includes: when the system is in a charging state or a discharging state, determining whether the total system power meets the first power constraint condition; if the total system power does not meet the first power constraint condition, selecting an equal current allocation strategy as the second power allocation strategy; wherein, the first power constraint condition is that the total system power is not greater than the total power limit at the overcurrent point.

[0008] In some embodiments, when the system is in a charging or discharging state and the total system power meets the first power constraint, if the total system power meets the second power constraint, a third power allocation strategy is selected, including: when the system is in a charging or discharging state, if the total system power meets the first power constraint; determining whether the total system power meets the second power constraint; if the total system power meets the second power constraint, selecting an equalization state of charge allocation strategy as the third power allocation strategy; wherein, the second power constraint is that the total system power is not greater than the maximum allowable total power limit of the energy storage battery pack.

[0009] In some embodiments, the method further includes: if the total power of the system does not meet the second power constraint condition; updating the maximum allowable power limit of each battery pack in the energy storage battery pack through a maximum allowable power limit amplification strategy; and selecting an equal state of charge allocation strategy as a third power allocation strategy based on the maximum allowable power limit.

[0010] In some embodiments, selecting a balanced state of charge (SCC) allocation strategy as the third power allocation strategy includes: setting a target SCC value for the energy storage battery pack; calculating the SCC difference between each battery pack in the energy storage battery pack based on the target SCC value; initializing the allocated power and power allocation state of each battery pack; and executing a loop process for each battery pack until a first preset condition is met, wherein the loop process includes: executing a power allocation process for each battery pack until a second preset condition is met, wherein the power allocation process includes: allocating power to each battery pack based on the SCC difference, the allocated power, and the total system power. The system updates the allocated power; it compares the allocated power with the maximum allowable power limit; if the allocated power is less than the maximum allowable power limit, it sets the power allocation status to incomplete; if the allocated power is not less than the maximum allowable power limit, it uses the maximum allowable power limit as the allocated power; it calculates the overflow power of each battery pack and sets the power allocation status to complete; it calculates the total overflow power of the energy storage battery pack based on the overflow power; when the total overflow power and the power allocation status of each battery pack do not meet the first preset condition, it uses the total overflow power as the total system power and executes the power allocation process for each battery pack.

[0011] In some embodiments, power allocation is performed on each battery pack based on the state-of-charge difference, the allocated power, and the total system power, and the allocated power is updated, including: calculating the total state-of-charge difference of the energy storage battery pack based on the state-of-charge difference; calculating the power increment of each battery pack based on the state-of-charge difference, the total state-of-charge difference, and the total system power; and updating the allocated power based on the power increment and the allocated power.

[0012] In some embodiments, updating the maximum permissible power limit of each battery pack in the energy storage battery pack using a maximum permissible power limit amplification strategy includes: obtaining the maximum permissible power limit of each battery pack in the energy storage battery pack; obtaining the overcurrent point power limit of each battery pack; calculating the total maximum permissible power limit of the energy storage battery pack based on the maximum permissible power limit of each battery pack; calculating the target amplification power based on the total system power and the total maximum permissible power limit; calculating the maximum permissible power difference of each battery pack based on the overcurrent point power limit and the maximum permissible power limit; and updating the maximum permissible power limit of each battery pack based on the maximum permissible power difference, the target amplification power, and the maximum permissible power limit.

[0013] To solve the above-mentioned technical problems, another technical solution adopted in the embodiments of this application is: to provide an energy management system, including: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the above-mentioned method.

[0014] To solve the above-mentioned technical problems, another technical solution adopted in the embodiments of this application is: to provide a non-volatile computer-readable storage medium that stores computer-executable instructions, which, when executed by the energy management system, cause the energy management system to perform the above-mentioned method.

[0015] Unlike related technologies, this application provides a power allocation method, an energy management system, and a storage medium. When the system is in a charging or discharging state, if the total system power meets both the second and first power constraints, the power of each battery pack is adjusted according to a balanced state of charge (SOC) allocation strategy to make the SOC more consistent, improving power balance and system load capacity. When the total system power does not meet the second power constraint but meets the first, a maximum allowable power limit amplification strategy is adopted to fully release power potential without exceeding safe limits. When the first power constraint is not met, an equal current allocation strategy is adopted to avoid overcurrent in a single pack, improving system stability, safety, and cell lifespan. Furthermore, when the system is in an idle state, a maximum allowable power ratio allocation strategy is selected for power allocation. Based on this, both battery pack balance and system power output are considered, improving the performance and operational stability of the energy storage system. Attached Figure Description

[0016] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings do not constitute a limit to scale.

[0017] Figure 1 is a flowchart of a power allocation method provided in an embodiment of this application;

[0018] Figure 2 is a flowchart of a balanced charge state allocation strategy provided in an embodiment of this application;

[0019] Figure 3 is a schematic diagram of the hardware structure of an energy management system for performing a power allocation method according to an embodiment of this application. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and thoroughly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application. It should be noted that, unless otherwise specified, the various features in the embodiments of this application can be combined with each other, and all are within the protection scope of this application.

[0021] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and are not used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and are not limited in number; for example, a first object can be one or more.

[0022] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application.

[0023] Please refer to Figure 1, which is a flowchart of a power allocation method provided in an embodiment of this application. As shown in Figure 1, the method is applied to the energy management system of an energy storage system, including steps S1-S5:

[0024] S1: Obtain the total system power of the energy storage system.

[0025] The real-time operating parameters of each battery pack are obtained from the battery management system (BMS) of each battery pack. The operating parameters include: the state of charge (SOC) of the battery pack, which represents the percentage of the battery's remaining capacity relative to its rated capacity; the maximum allowable power (SOP) limit of the battery pack, which represents the battery's available charge and discharge power capability in the current state, and its magnitude is affected by factors such as SOC, state of health (SOH), temperature, and internal resistance; the battery pack terminal voltage U; the battery pack terminal current I; and the battery pack status flag information (such as fault flags and offline flags).

[0026] Based on the battery pack terminal voltage and battery pack terminal current, according to the formula Calculate the instantaneous power of each battery pack. ;Instantaneous power This refers to the charging process ( >0), the instantaneous power absorbed by the battery from the outside; or during discharge ( <0, the instantaneous power released by the battery to the outside.

[0027] The instantaneous power of all online battery packs is summed to obtain the total system power of the current energy storage system:

[0028] ;

[0029] Where N is the number of battery packs currently online.

[0030] The calculation process further includes: filtering the collected voltage and current data to eliminate transient noise; and marking the battery pack as unusable and excluding its data from the total power calculation when abnormal battery pack data or communication interruption is detected.

[0031] The total system power, along with the SOC and SOP limits of each battery pack, are output to the Energy Management System (EMS) as the basis for subsequent power allocation and scheduling control.

[0032] S2: Based on the total system power, obtain the system state of the energy storage system.

[0033] To avoid misjudgments caused by instantaneous fluctuations, a power judgment threshold is preset. The threshold is determined based on the number of battery packs, sampling accuracy, and system noise level, and is used to define the range of "close to zero".

[0034] Based on total system power With power determination threshold Determine the system status of the energy storage system, specifically including:

[0035] when When this occurs, the system is determined to be in a charging state, meaning the entire system is in the process of absorbing external energy.

[0036] when When the system is in a discharge state, it is determined that the entire system is releasing energy to the outside.

[0037] when When the system is in an idle state, it is determined that no significant energy exchange has occurred in the system as a whole.

[0038] The system status is output as an operating indicator signal to guide the selection of subsequent power allocation strategies.

[0039] S3: When the system is in an idle state, select the first power allocation strategy.

[0040] When the system is in an idle state, the maximum allowable power ratio allocation strategy is selected as the first power allocation strategy.

[0041] When the system state is determined to be idle based on the total system power obtained in step S1, the following power allocation process is executed:

[0042] When the system is in an idle state, it means that no charging or discharging process has taken place. At this time, it is necessary to set the initial power allocation strategy according to the upcoming operating mode (charging or discharging). If not set properly, it may lead to overcurrent in individual battery packs, increased SOC differences, or decreased system efficiency.

[0043] When the energy storage system is operating in conjunction with the grid-side energy storage converter (PCS), the PCS will issue a total charging power command or a total discharging power command, and ensure that the command does not exceed the maximum allowable total power limit (SOP limit) of the energy storage battery pack reported by the system, that is, the SOP limit of total charging or total discharging.

[0044] In this scenario, the first power allocation strategy is the SOP (Maximum Allowable Power) proportional allocation strategy: if the PCS issues a total charging power command, the power is allocated according to the charging SOP ratio of each battery pack; if the PCS issues a total discharging power command, the power is allocated according to the discharging SOP ratio of each battery pack. The allocation ratio is calculated using the following formula:

[0045] ;

[0046] in, For the first SOP limits for each battery pack This refers to the total SOP limit for energy storage battery packs.

[0047] For example, when the PCS issues a total charging power command, if the SOP limit of battery pack A is 20 kW and the SOP limit of battery pack B is 40 kW, then the total SOP limit of the energy storage battery pack is 60 kW. When the PCS issues a total charging power command requiring a total system power of 30 kW, the system allocates power according to the SOP ratio to obtain the allocated power for battery pack A. The power distribution of battery pack B is 10kW. It is 20kW.

[0048] In this embodiment, when the energy storage system is determined to be in an idle state, the execution of the first power allocation strategy can rationally plan the output or energy absorption of each battery pack before charging or discharging begins. This effectively avoids damage to individual battery packs caused by overcurrent or uneven current distribution, while suppressing the expansion of SOC differences. When used in conjunction with a grid-side energy storage converter (PCS), by allocating power according to the SOP ratio of each battery pack's charging or discharging, the available power capacity of each battery pack can be fully utilized, ensuring that the total system power does not exceed the total SOP limit, thus achieving safe and efficient power output.

[0049] S4: When the system is in a charging or discharging state and the total power of the system does not meet the first power constraint, select the second power allocation strategy.

[0050] Specifically, when the system is in a charging or discharging state and the total system power does not meet the first power constraint condition, a second power allocation strategy is selected, including: when the system is in a charging or discharging state, determining whether the total system power meets the first power constraint condition; if the total system power does not meet the first power constraint condition, selecting an equal current allocation strategy as the second power allocation strategy; wherein, the first power constraint condition is that the total system power is not greater than the total power limit at the overcurrent point.

[0051] When the system status indicates it is in charging or discharging mode, it is necessary to further verify whether there is an overcurrent risk in the current system power. Specifically, firstly, the battery voltage U and its overcurrent protection set current value for each battery pack are obtained. The overcurrent point power limit for each battery pack is calculated using the following formula. :

[0052] ;

[0053] in, This indicates the maximum power threshold that the battery pack can safely withstand under the current voltage. Based on the overcurrent point power limits of all battery packs, the total overcurrent point power limit of the system is obtained by summing them up, which is the upper limit of the total power that the system can safely withstand under the current conditions.

[0054] Then, the total system power is compared with the total power limit at the overcurrent point:

[0055] If the total power of the system is not greater than the total power limit of the overcurrent point, it indicates that the system is operating within a safe range and can be executed according to the power allocation strategy in step S5 without triggering overcurrent protection.

[0056] If the total power of the system is greater than the total power limit at the overcurrent point, it indicates that the current total power has exceeded the overcurrent safety capability of some battery packs. In this case, the distribution strategy needs to be adjusted. An equal current distribution strategy (second power distribution strategy) can be adopted to ensure that each battery pack bears the same current on the battery side, thereby ensuring that all battery packs approach the overcurrent point at the same time and avoiding individual battery packs from triggering higher-level overcurrent protection in advance.

[0057] The equal current distribution strategy is based on the principle of: according to the power formula When the current of each battery pack is controlled to be the same, that is, the same target current is set. Then the instantaneous power of each battery pack Its terminal voltage Proportional. It can be understood that the voltage ratio of each battery pack is its power distribution ratio, and the formula for calculating the distribution ratio is as follows:

[0058] ;

[0059] in, For the first The battery voltage of each battery pack.

[0060] This method ensures that all battery packs experience the same current on the battery side, thus preventing individual battery packs from experiencing excessive current due to voltage differences and triggering overcurrent points.

[0061] For example, suppose the system has three battery packs A, B, and C. Their voltages are respectively... 300V It is 310V. 290V, target current If set to 10A, then the power of each battery pack is: Total system power The total power is 9000W. The power distribution of each battery pack is 33.3%, 34.4%, and 32.2%, respectively. This shows that the higher voltage battery pack handles more power, while the lower voltage pack handles less power. All battery packs have the same current, thus avoiding the risk of overcurrent.

[0062] In this embodiment, by comparing the total system power with the overcurrent point power limit when the system is in charging or discharging state, potential overcurrent risks can be identified in advance during power allocation. When the total system power exceeds the overcurrent point power limit, an equal current allocation strategy is triggered in a timely manner to ensure that the current borne by each battery pack on the battery side remains consistent. This guarantees that each battery pack reaches the same protection level simultaneously when approaching the overcurrent point, avoiding the problem of individual battery packs prematurely triggering high-level overcurrent protection, which could lead to a sudden drop in the power of the entire system or even a system disconnection. This approach not only effectively avoids the safety hazards caused by single-pack overload but also improves the power output stability and overcurrent resistance of the entire energy storage system, thereby extending battery pack life and enhancing the system's operational reliability under complex operating conditions.

[0063] Another scenario is when the system is operating under blind charging or direct load. Because it lacks intelligent SOP management based on real-time battery status, external power demands may not be constrained by the total SOP limit. The system may attempt to draw (or inject) power exceeding its total SOP limit from one or more battery packs. Therefore, an equal current distribution strategy (second power distribution strategy) can be adopted to ensure that each battery pack experiences the same current on the battery side, thereby guaranteeing that all battery packs approach the overcurrent point simultaneously and preventing individual battery packs from prematurely triggering higher-level overcurrent protection.

[0064] In scenarios involving blind charging or direct load drive, an equal current distribution strategy ensures consistent current across all battery packs. Current balancing control prevents some packs from bearing excessive power due to voltage differences, thus reducing the risk of triggering overcurrent. This rational initial power allocation not only guarantees safe operation of each battery pack during the initial charging and discharging phases, improving system stability, but also provides a reliable foundation for subsequent dynamic power scheduling and SOC balancing. Ultimately, this enhances the overall energy storage system's charging and discharging efficiency, extends battery life, and ensures system operational safety.

[0065] S5: When the system is in a charging or discharging state and the total system power meets the first power constraint condition, if the total system power meets the second power constraint condition, select the third power allocation strategy.

[0066] Specifically, when the system is in a charging or discharging state and the total system power meets the first power constraint, if the total system power meets the second power constraint, a third power allocation strategy is selected, including: when the system is in a charging or discharging state and the total system power meets the first power constraint; determining whether the total system power meets the second power constraint; if the total system power meets the second power constraint, selecting the balanced charge state allocation strategy as the third power allocation strategy; wherein the second power constraint is that the total system power is not greater than the maximum allowable total power limit of the energy storage battery pack.

[0067] When the system is in a charging or discharging state, and the total system power meets the first power constraint (total system power not exceeding the overcurrent point power limit), it is then determined whether the total system power meets the second power constraint (total system power not exceeding the maximum allowable total power limit of the energy storage battery pack (SOP total limit)). It can be understood that when the total system power simultaneously meets both the first and second power constraints, it not only ensures that the current will not exceed the current safety boundary of the battery or device, avoiding overcurrent risks, but also guarantees that the battery can safely and continuously output / absorb the maximum power in the current state. Only then is the system allowed to use the balanced state of charge (SOC) allocation strategy to optimize the consistency within the energy storage battery pack.

[0068] Please refer to Figure 2, which is a flowchart of an equalization state of charge allocation strategy provided in an embodiment of this application. As shown in Figure 2, selecting the equalization state of charge allocation strategy as the third power allocation strategy includes steps S51-S54:

[0069] S51: Set the target state of charge value for the energy storage battery pack.

[0070] S52: Calculate the state of charge difference of each battery pack in the energy storage battery pack based on the target state of charge value.

[0071] S53: Initialize the allocated power and power allocation status of each battery pack.

[0072] First, set a target state of charge value that all battery packs should eventually approach. For example: setting during charging ; Setting during discharge .

[0073] Secondly, according to The state of charge difference of each battery pack can be calculated.

[0074] Assume the energy storage battery pack contains N battery packs, and let the first one be the Nth battery pack. One battery pack is When the system is in a charging state, the first... State of charge difference of individual battery packs When in a discharge state, .in, For the first The current state of charge (SOC) value of each battery pack. This is understandable. Reflecting the How much charge is a battery pack still away from its target state of charge? The battery pack that is further away should be allocated more power.

[0075] Before the cycle begins, the maximum allowable power limit for each battery pack can also be obtained. and total system power In addition, the allocated power of each battery pack also needs to be checked. Power distribution status of each battery pack Overflow power Total overflow power Perform initialization. That is: ; ; ; .in, This indicates that the battery pack allocation is complete. The battery pack has reached [number]. ,but Otherwise, it is 0.

[0076] S54: Execute a cyclic process for each battery pack until a first preset condition is met. The cyclic process includes: executing a power allocation process for each battery pack until a second preset condition is met. The power allocation process includes: allocating power to each battery pack based on the state-of-charge difference, allocated power, and total system power, and updating the allocated power; judging the allocated power and the maximum allowable power limit; if the allocated power is less than the maximum allowable power limit, setting the power allocation status to incomplete; if the allocated power is not less than the maximum allowable power limit, using the maximum allowable power limit as the allocated power; calculating the overflow power of each battery pack and setting the power allocation status to completed; calculating the total overflow power of the energy storage battery pack based on the overflow power; when the total overflow power and the power allocation status of each battery pack do not meet the first preset condition, using the total overflow power as the total system power, and executing the power allocation process for each battery pack. The first preset condition is that the total overflow power is 0 or the power allocation status of all battery packs is completed; the second preset condition is that the current battery pack is the last battery pack in the energy storage battery pack.

[0077] Specifically, based on the state-of-charge difference, allocated power, and total system power, power is allocated to each battery pack, and the allocated power is updated. This includes: calculating the total state-of-charge difference of the energy storage battery pack based on the state-of-charge difference; calculating the power increment of each battery pack based on the state-of-charge difference, the total state-of-charge difference, and the total system power; and updating the allocated power based on the power increment and the allocated power.

[0078] Iterate through N battery packs until the second preset condition is met (the current battery pack is the last battery pack in the energy storage battery pack). Then according to their respective Percentage Perform power allocation to update The allocation calculation formula is as follows:

[0079] ;

[0080] in, This represents the total difference in the state of charge of the energy storage battery pack; the current power increment of the battery pack is... .

[0081] Secondly, determine the updated Does it exceed the capacity of the battery pack? If it does not exceed the battery pack's capacity. This indicates that the allocation is valid. The thermal state remains at 0, meaning the power distribution of this battery pack is incomplete. If the power distribution exceeds the capacity of this battery pack... Then Revised to Additionally, the excess portion is recorded as overflow power. And calculate cumulatively to obtain At the same time, the battery pack is marked as completed. .

[0082] Subsequently, a termination condition determination phase is performed. The loop process ends when the total overflow power and the power allocation status of each battery pack meet a first preset condition. The first preset condition is that the total overflow power is 0 or the power allocation status of all battery packs is... Both are 1. It's understandable that if... This indicates that the total overflow power has been allocated and the process ends; if all battery packs are marked as Then all battery packs will meet the SOP limit, even if there are... If no further allocation is possible, the process ends; if neither of the above two conditions is met, proceed to the next stage.

[0083] When the total overflow power and the power distribution status of each battery pack do not meet the first preset condition, Then, the power allocation process is executed again for each battery pack, and the battery packs that have not been allocated are allocated again until the first preset condition is met.

[0084] Finally, output the final allocated power for each battery pack. (i=1,…,N); if there is unallocated total overflow power, i.e. And all battery packs If the value is 1, the residual power will be returned as an unallocated quantity, and the host computer will be advised to take measures such as derating, current limiting, or alarm.

[0085] For example, assuming the energy storage battery pack has 3 battery packs (A, B, C), the total system power that the current system needs to allocate is... It is 90kW. For a 100% charging scenario, the current state of charge values ​​of each battery pack are A=80%, B=70%, and C=60%, respectively, and the SOP limits of each battery pack are A=50kW, B=40kW, and C=30kW, respectively.

[0086] Calculate the state-of-charge difference for each battery pack, i.e.: , , The total difference in the state of charge of the energy storage battery pack is 20 + 30 + 40 = 90.

[0087] The first power allocation is based on the percentage of the difference in state of charge, i.e.: kW; It is 30 kW; It is 40 kW.

[0088] The allocated power is compared with its own SOP limit, that is: This allocation is legal. (Not completed despite meeting the deadline); This allocation is legal. ; At this point, it has exceeded its own SOP limit, so take... kW, (The battery pack has been allocated); Overflow power =10kW, accumulated to The results of this round are as follows: kW, allocated power: A=20kW, B=30kW, C=30kW.

[0089] Entering the termination condition judgment phase. Because... The value is not 0, and neither battery pack A nor battery pack B has been fully allocated, so a second allocation is required.

[0090] Will kW, and reset to zero. It should be noted that at this point, only battery packs A and B, which have not yet been allocated, need to be allocated.

[0091] At this point, the total state of charge difference of the energy storage battery pack is 20 + 30 = 50. Performing a secondary distribution calculation, we obtain: kW; It is 36 kW.

[0092] The allocated power is compared again with its own SOP limit: A: 24 < 50; B: 36 < 40. Neither exceeds the limit. Therefore... The current value is 0, which satisfies the first preset condition, thus ending the process.

[0093] The final allocation result is: kW kW kW; a total of 90kW, allocated and not exceeding its own SOP limit.

[0094] In this embodiment, power allocation is adaptively adjusted based on the difference between the current state of charge (SOC) value and the target SOC value of each battery pack. Under the premise of meeting the SOP limit of each battery pack, more power is allocated to battery packs with a larger SOC deviation from the target. The available power of the system is fully utilized through an iterative allocation mechanism to avoid resource waste. When the power cannot be fully allocated, the remaining power information can be output in a timely manner, which is convenient for the upper-level system to take power limiting or protection measures.

[0095] In some embodiments, the method further includes: if the total power of the system does not meet the second power constraint condition; updating the maximum allowable power limit of each battery pack in the energy storage battery pack through a maximum allowable power limit amplification strategy; and selecting an equal state of charge allocation strategy as a third power allocation strategy based on the maximum allowable power limit.

[0096] Specifically, the maximum permissible power limit of each battery pack in the energy storage battery pack is updated through a maximum permissible power limit amplification strategy. This includes: obtaining the maximum permissible power limit of each battery pack in the energy storage battery pack; obtaining the overcurrent point power limit of each battery pack; calculating the total maximum permissible power limit of the energy storage battery pack based on the maximum permissible power limits of each battery pack; calculating the target amplification power based on the total system power and the total maximum permissible power limit; calculating the maximum permissible power difference of each battery pack based on the overcurrent point power limit and the maximum permissible power limit; and updating the maximum permissible power limit of each battery pack based on the maximum permissible power difference, the target amplification power, and the maximum permissible power limit.

[0097] When the system is in a charging or discharging state, if the first power constraint condition is met, but the second power constraint condition is not met (i.e., ... When the system is in a state of overcurrent, the maximum allowable power limit amplification strategy (SOP limit amplification strategy) can be used to amplify the total SOP limit to meet the total system power demand, while ensuring that the total power limit at the overcurrent point is not exceeded. The implementation process of the SOP limit amplification strategy is as follows:

[0098] Obtain the overcurrent point power limit for each battery pack. And obtain the maximum allowable power limit for each battery pack. The total SOP limit is calculated based on the SOP limits of each battery pack. ;

[0099] Calculate the maximum permissible power difference for each battery pack based on the overcurrent point power limit and the maximum permissible power limit. ,Right now: .

[0100] Based on the total system power and maximum permissible total power limit Calculate the target amplification power ,Right now: .

[0101] Update the target amplification power according to the proportion of the maximum allowable power difference. ,Right now:

[0102] ;

[0103] Understandably, when the total system power exceeds the original SOP (State of Operation) limit but has not yet reached the overcurrent point, the SOP limit of each battery pack is increased proportionally to the margin between each battery pack and the overcurrent point power limit, allowing the system to safely output / absorb more power. Based on this, the aforementioned balanced state of charge (SOC) allocation strategy is then used for power distribution.

[0104] For example, battery packs A and B, A has an original SOP limit of 10kW, B has an original SOP limit of 15kW, A has an overcurrent point power limit of 20kW, B has an overcurrent point power limit of 18kW, A has a current state of charge of 40%, and B has a current state of charge of 60%.

[0105] First, the SOP limit is increased: total system power = 30kW > original total SOP limit = 25kW;

[0106] Calculate the maximum allowable power difference between battery pack A and battery pack B: A = 20 - 10 = 10kW, B = 18 - 15 = 3kW;

[0107] Secondly, the power increase is proportional to the maximum allowable power difference: the increase for battery A = (30-25) × (10 / (10+3)) ≈ 3.85kW, that is, the SOP limit of the updated battery pack A is 13.85kW; the increase for battery pack B = (30-25) × (3 / 13) ≈ 1.15kW, that is, the SOP limit of the updated battery pack B is 16.15kW.

[0108] Subsequently, a balanced state of charge (SOP) allocation strategy is applied: battery pack A has a low current SOP value and should be allocated more power; battery pack B has a high current SOP value and should be allocated less power, but the allocated power cannot exceed their respective updated SOP limits. For a detailed flowchart of the balanced SOP allocation strategy, please refer to step S5 above.

[0109] In this embodiment, when the total system power exceeds the SOP (State of Operation) limit but remains below the overcurrent point power limit, the SOP limit of each battery pack can be appropriately increased to cover the current real-time power demand. The power is then allocated according to the distance ratio between the SOP limit and the overcurrent point power limit of each battery pack. On one hand, this fully releases the power potential of the battery packs, avoiding the problem of limited total system power caused by simply allocating power according to the original SOP limit ratio, thereby improving charging and discharging efficiency and system load capacity. On the other hand, the safe distance between each battery pack and the overcurrent point power limit is considered during the amplification process, ensuring that the power of each battery pack remains within a safe range, preventing premature triggering of overcurrent protection, and improving battery life and system operational safety. Furthermore, it can be combined with a balanced state of charge (SOC) allocation strategy to achieve balanced SOC control of the battery packs while amplifying power, further optimizing the overall system performance and stability.

[0110] This application provides a power allocation method. By dynamically monitoring and calculating the total system power, the SOC of each battery pack, and the SOP limit, when the total system power is less than the maximum allowable total power limit of the energy storage battery pack and not greater than the total power limit at the overcurrent point, the power allocation is adjusted according to the SOC state of each battery pack. This makes the SOC of each battery pack more consistent, thereby improving the power balance between battery packs, maximizing the charging speed and load capacity throughout the entire service life, and taking into account the SOP limit of each battery pack, ensuring it does not exceed the safe power boundary, and effectively extending the cell cycle life. When the total system power exceeds the total SOP limit but does not reach the total power limit at the overcurrent point, an SOP limit amplification strategy is used to appropriately amplify the SOP limit of each battery pack according to the safe distance ratio from the overcurrent point power limit to meet the actual power demand, while ensuring that the amplified power is still within the safe range, fully releasing the system power potential and improving charging and discharging efficiency. When the power exceeds the total power limit at the overcurrent point, an equal current distribution strategy is adopted to ensure that all battery packs operate at the same current simultaneously. This triggers lower-level overcurrent protection simultaneously when necessary, preventing severe overcurrent in individual battery packs and improving the overall stability and safety of the system. Furthermore, by combining SOC balancing with SOP limit management, dynamic optimization control of the SOC and power of each battery pack is achieved under various operating conditions. This balances system power utilization, battery life, and charge / discharge performance, ensuring a significant improvement in the reliability, efficiency, and safety of the entire energy storage system in practical applications.

[0111] This application also provides an energy management system 200. Referring to FIG3, it shows a schematic diagram of the hardware structure of the energy management system 200 capable of executing the methods of the above embodiments. The energy management system 200 includes: at least one processor 210; and a memory 220 communicatively connected to the at least one processor 210. FIG3 uses one processor 210 as an example. The memory 220 stores instructions executable by the at least one processor 210. The instructions are executed by the at least one processor 210 to enable the at least one processor 210 to execute the power distribution method of the above embodiments. The processor 210 and the memory 220 can be connected via a bus or other means; FIG3 uses a bus connection as an example.

[0112] The memory 220, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules, such as the program instructions / modules corresponding to the power allocation method in the embodiments of this application. The processor 210 executes various functional applications and data processing of the server by running the non-volatile software programs, instructions, and modules stored in the memory 220, thereby implementing the power allocation method of the above embodiments.

[0113] Memory 220 may include a stored program area and a stored data area, wherein the stored program area may store the operating system and applications required for at least one function; the stored data area may store data created based on the use of the computing device, etc. Furthermore, memory 220 may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some embodiments, memory 220 may optionally include memory remotely located relative to processor 210, and these remote memories may be connected to the computing device via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0114] One or more modules are stored in memory 220 and, when executed by one or more processors 210, perform the power allocation method of the above embodiments.

[0115] The above-described product can execute the method provided in the embodiments of this application, and has the corresponding functional modules and beneficial effects for executing the method. Technical details not described in detail in this embodiment can be found in the power allocation method of the embodiments of this application.

[0116] This application provides a non-volatile computer-readable storage medium storing computer-executable instructions that are executed by one or more processors to enable at least one processor to perform the power allocation method described in the above embodiments. For example, the non-volatile computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a compact disc read-only memory (CDROM), magnetic tape, floppy disk, or optical data storage device, etc.

[0117] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0118] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of this application as described above, which are not provided in detail for the sake of brevity; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A power distribution method applied to an energy storage system, characterized in that, The method includes: obtaining the total system power of the energy storage system; determining the system state of the energy storage system based on the total system power; when the system state is idle, selecting a maximum allowable power ratio allocation strategy as a first power allocation strategy; wherein, the idle state is the system state when the energy storage system has not yet undergone charging or discharging; when the system state is charging or discharging, and the total system power does not meet a first power constraint condition, selecting an equal current allocation strategy as a second power allocation strategy; wherein, the first power constraint condition is that the total system power is not greater than the total power limit at the overcurrent point; when the system state is charging or discharging, and the total system power meets the first power constraint condition, if the total system power meets the second power constraint condition, selecting an equal state of charge allocation strategy as a third power allocation strategy; wherein, the second power constraint condition is that the total system power is not greater than the maximum allowable total power limit of the energy storage battery pack.

2. The power distribution method according to claim 1, characterized in that, The step of selecting an equal current allocation strategy as the second power allocation strategy when the system state is in a charging state or a discharging state and the total system power does not meet the first power constraint condition includes: when the system state is in the charging state or the discharging state, determining whether the total system power meets the first power constraint condition; if the total system power does not meet the first power constraint condition, selecting the equal current allocation strategy as the second power allocation strategy.

3. The power distribution method according to claim 2, characterized in that, When the system state is either the charging state or the discharging state, and the total system power satisfies the first power constraint condition, if the total system power satisfies the second power constraint condition, selecting the balanced state of charge allocation strategy as the third power allocation strategy includes: when the system state is either the charging state or the discharging state, if the total system power satisfies the first power constraint condition; determining whether the total system power satisfies the second power constraint condition; if the total system power satisfies the second power constraint condition, selecting the balanced state of charge allocation strategy as the third power allocation strategy.

4. The power distribution method according to claim 3, characterized in that, The method further includes: if the total power of the system does not meet the second power constraint condition; updating the maximum allowable power limit of each battery pack in the energy storage battery pack through the maximum allowable power limit amplification strategy; and selecting the balanced state of charge allocation strategy as the third power allocation strategy based on the maximum allowable power limit.

5. The power distribution method according to claim 4, characterized in that, The selection of a balanced state of charge (SCC) allocation strategy as the third power allocation strategy includes: setting a target SCC value for the energy storage battery pack; calculating the SCC difference between each battery pack in the energy storage battery pack based on the target SCC value; initializing the allocated power and power allocation state of each battery pack; and executing a loop process for each battery pack until a first preset condition is met, wherein the loop process includes: executing a power allocation process for each battery pack until a second preset condition is met, wherein the power allocation process includes: allocating power to each battery pack based on the SCC difference, the allocated power, and the total system power, and updating the allocated power. The system determines the allocated power and the maximum allowable power limit. If the allocated power is less than the maximum allowable power limit, the power allocation status is set to incomplete. If the allocated power is not less than the maximum allowable power limit, the maximum allowable power limit is used as the allocated power. The system calculates the overflow power of each battery pack and sets the power allocation status to complete. Based on the overflow power, the system calculates the total overflow power of the energy storage battery pack. When the total overflow power and the power allocation status of each battery pack do not meet the first preset condition, the total overflow power is used as the total system power, and the power allocation process is executed on each battery pack.

6. The power distribution method according to claim 5, characterized in that, The step of allocating power to each battery pack based on the state-of-charge difference, the allocated power, and the total system power, and updating the allocated power, includes: calculating the total state-of-charge difference of the energy storage battery pack based on the state-of-charge difference; calculating the power increment of each battery pack based on the state-of-charge difference, the total state-of-charge difference, and the total system power; and updating the allocated power based on the power increment and the allocated power.

7. The power distribution method according to claim 4, characterized in that, The step of updating the maximum permissible power limit of each battery pack in the energy storage battery pack using the maximum permissible power limit amplification strategy includes: obtaining the maximum permissible power limit of each battery pack in the energy storage battery pack; obtaining the overcurrent point power limit of each battery pack; calculating the total maximum permissible power limit of the energy storage battery pack based on the maximum permissible power limit of each battery pack; calculating the target amplification power based on the total system power and the total maximum permissible power limit; calculating the maximum permissible power difference of each battery pack based on the overcurrent point power limit and the maximum permissible power limit; and updating the maximum permissible power limit of each battery pack based on the maximum permissible power difference, the target amplification power, and the maximum permissible power limit.

8. An energy management system, characterized in that, include: At least one processor; And a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1-7.

9. A non-volatile computer-readable storage medium, characterized in that, The non-volatile computer-readable storage medium stores computer-executable instructions that, when executed by the energy management system, cause the energy management system to perform the method described in any one of claims 1-7.

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