A power distribution method and device of an energy storage unit, an apparatus, and a storage medium

Abstract

The application discloses a power distribution method and device of an energy storage unit, equipment and a storage medium. The method comprises the following steps: for each energy storage unit, determining the charging and discharging working condition corresponding to the energy storage unit according to the station-level total active power instruction, and determining the state of charge conversion coefficient according to the charging and discharging working condition and the state of charge of the energy storage unit; calculating the comprehensive weight corresponding to the energy storage unit according to the state of charge conversion coefficient and the available capacity of the energy storage unit; and distributing the single active power instruction for each energy storage unit according to the station-level total active power instruction, the comprehensive weights corresponding to all energy storage units and the active power limit value corresponding to each energy storage unit. The method not only ensures that the power distributed to each energy storage unit is within the limited allowable range, but also provides tracking distribution capability of the total active power instruction.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of power technology, and in particular to a power distribution method, apparatus, device and storage medium for an energy storage unit. Background Technology

[0002] In energy storage power stations or new energy power plants, after receiving the total active power command at the station level from the superior dispatcher or station-level controller, the multi-machine system needs to distribute the total command to the energy storage units in each grid-type energy storage device.

[0003] Currently, the method for allocating total active power commands at the station level is usually based on rated power or capacity ratio, which can achieve a relatively simple proportional sharing under steady state. However, due to the differences in real-time state of charge (SOC) among energy storage units, and the continuous changes in the available capacity, aging degree, and operating status of energy storage units over time, simply using a capacity-ratio allocation method can lead to energy storage units with low SOC continuing to bear a large discharge power, or energy storage units with high SOC continuing to bear a large charging power. This increases the risk of over-discharge, over-charge, premature shutdown, and widening of the SOC deviation among multiple units. Summary of the Invention

[0004] This invention provides a power allocation method, apparatus, device, and storage medium for energy storage units, which not only ensures that the power allocated to each energy storage unit is within the allowable limits, but also provides the ability to track and allocate total active power commands.

[0005] In a first aspect, embodiments of the present invention provide a power allocation method for an energy storage unit, the method comprising: For each energy storage unit, the charging and discharging conditions corresponding to the energy storage unit are determined according to the total active power command at the station level, and the state of charge conversion factor is determined according to the charging and discharging conditions and the state of charge of the energy storage unit.

[0006] The comprehensive weight of the energy storage unit is calculated based on the state of charge conversion factor and the available capacity of the energy storage unit.

[0007] Based on the total active power command at the station level, the comprehensive weight of all energy storage units, and the active power limit of each energy storage unit, a single active power command is allocated to each energy storage unit.

[0008] The power allocation method for energy storage units provided in this invention first determines the charging and discharging conditions and state of charge (SOC) of each energy storage unit based on the station-level total active power command. This determines the SOC conversion factor for the energy storage unit under its current operating condition, quantifying how much conversion factor the energy storage unit bears in the allocation of charging and discharging conditions. Then, based on the SOC conversion factor and the available capacity of the energy storage unit, the comprehensive weight corresponding to the energy storage unit is calculated. This method replaces the current allocation based solely on capacity or rated power, using the energy storage unit capacity as the basic weight and the real-time SOC as a dynamic correction factor. This provides a quantitative basis for subsequent power allocation to simultaneously reflect equipment scale and available energy status, thus solving the problem of allocation based solely on capacity or rated power. It also reduces the risks of over-discharging, over-charging, premature shutdown, and increased SOC deviation among multiple units during the power allocation process. First, the system allocates the active power that each energy storage unit can handle according to its comprehensive weight and the station-level total active power command. Then, based on whether the allocated active power exceeds its active power limit, the system dynamically adjusts the active power allocated to each energy storage unit with different active power limits. Finally, it determines and allocates a single active power command to each energy storage unit. This achieves coordinated control that fully considers the power limit of a single unit and the redistribution of surplus power. It not only ensures that the power allocated to each energy storage unit is within the allowable limit, but also provides the ability to track and allocate the total active power command.

[0009] Secondly, embodiments of the present invention also provide a power distribution device for an energy storage unit, the device comprising: The status determination module is used to determine the charging and discharging conditions of each energy storage unit based on the total active power command at the station level, and to determine the state of charge conversion factor based on the charging and discharging conditions and the state of charge of the energy storage unit.

[0010] The calculation module is used to calculate the comprehensive weight of the energy storage unit based on the state of charge conversion factor and the available capacity of the energy storage unit.

[0011] The allocation module is used to allocate a single active power command to each energy storage unit based on the total active power command at the station level, the comprehensive weight of all energy storage units, and the active power limit of each energy storage unit.

[0012] Thirdly, embodiments of the present invention also provide an electronic device, the electronic device comprising: At least one processor; and A memory that is communicatively connected to at least one processor; wherein, The memory stores a computer program that can be executed by at least one processor, such that the at least one processor is able to execute the power distribution method of the energy storage unit according to any embodiment of the present invention.

[0013] Fourthly, embodiments of the present invention also provide a computer-readable storage medium storing computer instructions, which are used to cause a processor to execute and implement the power allocation method of the energy storage unit of any embodiment of the present invention.

[0014] Fifthly, embodiments of the present invention also provide a computer program product, including a computer program that, when executed by a processor, implements the power allocation method of the energy storage unit of any embodiment of the present invention.

[0015] It should be noted that the aforementioned computer instructions may be stored, in whole or in part, on a computer-readable storage medium. This computer-readable storage medium may be packaged together with the processor of the power distribution device of the energy storage unit, or it may be packaged separately from the processor of the power distribution device of the energy storage unit; this application does not impose any limitations on this.

[0016] The descriptions of the second, third, fourth, and fifth aspects in this application can be referred to the detailed description of the first aspect; and the beneficial effects of the descriptions of the second, third, fourth, and fifth aspects can be referred to the analysis of the beneficial effects of the first aspect, which will not be repeated here.

[0017] In this application, the name of the power distribution device of the aforementioned energy storage unit does not limit the device or functional module itself. In actual implementation, these devices or functional modules may appear under other names. As long as the function of each device or functional module is similar to that of this application, it falls within the scope of the claims of this application and its equivalents.

[0018] These or other aspects of this application will become more readily apparent in the following description. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A flowchart illustrating a power allocation method for an energy storage unit provided in an embodiment of the present invention; Figure 2 A flowchart illustrating another power allocation method for an energy storage unit provided in an embodiment of the present invention; Figure 3 A structural diagram of a power distribution device for an energy storage unit provided in an embodiment of the present invention; Figure 4This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0022] In this article, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0023] The terms “initial” and “target” in the specification and drawings of this application are used to distinguish different objects or to distinguish different treatments of the same object, rather than to describe a specific order of objects.

[0024] Furthermore, the terms "comprising" and "having," and any variations thereof, used in the description of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include other steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0025] Before discussing the exemplary embodiments in more detail, it should be noted that some exemplary embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe the operations (or steps) as sequential processes, many of these operations can be performed in parallel, concurrently, or simultaneously. Furthermore, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but may also have additional steps not included in the figures. The process can correspond to a method, function, procedure, subroutine, subroutine, etc. Moreover, embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0026] It should be noted that in the embodiments of this application, the words "exemplary" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the words "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0027] In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0028] Figure 1 This is a flowchart illustrating a power allocation method for an energy storage unit according to an embodiment of the present invention. This embodiment is applicable to scenarios involving grid-connected energy storage power stations or new energy grid-connected power plants, addressing the need to rationally allocate individual active power commands to multiple energy storage units based on the total active power command at the station level. This method can be executed by a power allocation device within the energy storage unit. This power allocation device can be implemented in hardware and / or software and can be configured within an electronic device. In this embodiment, the electronic device can be a coordination controller for the grid-connected energy storage power station or new energy grid-connected power plant. (Continue referring to...) Figure 1 This embodiment specifically includes: S101. For each energy storage unit, determine the corresponding charging and discharging conditions of the energy storage unit according to the station-level total active power command, and determine the state of charge conversion factor according to the charging and discharging conditions and the state of charge of the energy storage unit.

[0029] Among them, an energy storage unit is an independent functional unit / minimum standardized module capable of storing energy and releasing stored energy as needed. The station-level total active power command is the command issued corresponding to the total active power at the station level. Charge and discharge conditions include charging and discharging conditions, mainly referring to whether the energy storage unit is currently operating in a charging or discharging state. State of charge (SOC) refers to the current remaining usable capacity of the energy storage unit's battery; SOC can be abbreviated as State of Charge. The SOC conversion factor is used to characterize how much power the energy storage unit can handle during charge and discharge distribution.

[0030] Specifically, for each energy storage unit, its corresponding state of charge (SOC) differs, thus its active power capacity also differs. Therefore, in actual allocation, the sign of the total active power at the station level can be used to determine whether the current operating condition is charging, discharging, or can be set to zero or maintained by local grid control to maintain the grid connection point voltage and frequency. Then, based on the energy storage unit's state and its corresponding SOC, the active power capacity that each energy storage unit can handle is determined, i.e., the SOC conversion factor.

[0031] S102. Calculate the comprehensive weight of the energy storage unit based on the state of charge conversion factor and the available capacity of the energy storage unit.

[0032] The available capacity refers to the effective amount of electricity that an energy storage unit can safely and stably release under specified operating conditions (such as temperature, charge / discharge rate, cutoff voltage, protection threshold, etc.), excluding the capacity that cannot be released due to system protection reserves, aging losses, low-temperature degradation, etc. The comprehensive weight is used to characterize the power share that energy storage units with different states of charge can handle.

[0033] Specifically, since different energy storage units have their corresponding available capacity, if the active power allocated to them exceeds their corresponding available capacity, the energy storage unit cannot continue to work. Therefore, the state of charge conversion factor can be used to correct the available capacity of the energy storage unit, so as to calculate a more accurate comprehensive weight corresponding to the energy storage unit.

[0034] In this embodiment, for each energy storage unit, the charging and discharging conditions and state of charge of the energy storage unit are first determined according to the total active power command at the station level. This determines the state of charge conversion factor of the energy storage unit under its current conditions, which can quantify how much conversion factor the energy storage unit bears in the allocation of charging and discharging conditions. Then, the comprehensive weight corresponding to the energy storage unit is calculated based on the state of charge conversion factor and the available capacity of the energy storage unit. This can replace the current allocation based solely on capacity or rated power. Instead, the capacity of the energy storage unit is used as the basic weight, and the real-time state of charge is used as a dynamic correction factor. This provides a quantitative basis for subsequent power allocation to simultaneously reflect the equipment scale and available energy status. Therefore, it solves the problem of allocation based solely on capacity or rated power and reduces the risks of over-discharge, over-charge, premature shutdown, and increased state of charge deviation among multiple units during the power allocation process.

[0035] S103. Based on the station-level total active power command, the comprehensive weight of all energy storage units, and the active power limit of each energy storage unit, allocate a single active power command to each energy storage unit.

[0036] The active power limit is the power that the energy storage unit actually outputs / absorbs (corresponding to discharge / charge conditions) and can be converted into effective work (heat generation, drive circuit, heat exchange). A single active power command is an active power command specifically allocated to a single energy storage unit for charging and discharging.

[0037] Specifically, after determining the comprehensive weight corresponding to each energy storage unit, the amount of single active power that each energy storage unit can undertake from the total active power at the station level can be determined according to the comprehensive weight corresponding to each energy storage unit and the ratio of its corresponding active power limit to the comprehensive weight corresponding to all energy storage units. Then, a single active power instruction can be determined and allocated to each energy storage unit.

[0038] For example, firstly, the theoretical active power that each energy storage unit can handle is allocated according to the comprehensive weight corresponding to each energy storage unit and the total active power command at the station level; then, since different energy storage units have different active power limits, for each energy storage unit whose theoretical active power exceeds its active power limit, its active power limit can be directly used as the actual active power; and since the aforementioned energy storage units cannot handle all the theoretical active power originally allocated to them, the total active power that these energy storage units cannot handle can be further allocated to those energy storage units whose theoretical active power does not exceed their active power limit; finally, the single active power command can be determined and allocated to each energy storage unit.

[0039] In this embodiment, the active power that the energy storage unit can undertake is first allocated according to the comprehensive weight corresponding to the energy storage unit and the total active power command at the station level. Then, the active power allocated to each energy storage unit is dynamically adjusted according to whether the allocated active power exceeds its active power limit. Finally, a single active power command is determined and allocated to each energy storage unit. This achieves coordinated control that fully considers the power limit of a single unit and the redistribution of the remaining power. It not only ensures that the power allocated to each energy storage unit is within the limit, but also provides the ability to track and allocate the total active power command.

[0040] The power allocation method for energy storage units provided in this invention first determines the charging and discharging conditions and state of charge (SOC) of each energy storage unit based on the station-level total active power command. This determines the SOC conversion factor for the energy storage unit under its current operating condition, quantifying how much conversion factor the energy storage unit bears in the allocation of charging and discharging conditions. Then, based on the SOC conversion factor and the available capacity of the energy storage unit, the comprehensive weight corresponding to the energy storage unit is calculated. This method replaces the current allocation based solely on capacity or rated power, using the energy storage unit capacity as the basic weight and the real-time SOC as a dynamic correction factor. This provides a quantitative basis for subsequent power allocation to simultaneously reflect equipment scale and available energy status, thus solving the problem of allocation based solely on capacity or rated power. It also reduces the risks of over-discharging, over-charging, premature shutdown, and increased SOC deviation among multiple units during the power allocation process. First, the system allocates the active power that each energy storage unit can handle according to its comprehensive weight and the station-level total active power command. Then, based on whether the allocated active power exceeds its active power limit, the system dynamically adjusts the active power allocated to each energy storage unit with different active power limits. Finally, it determines and allocates a single active power command to each energy storage unit. This achieves coordinated control that fully considers the power limit of a single unit and the redistribution of surplus power. It not only ensures that the power allocated to each energy storage unit is within the allowable limit, but also provides the ability to track and allocate the total active power command.

[0041] Figure 2 This is a flowchart illustrating another power allocation method for an energy storage unit provided by an embodiment of the present invention. This embodiment, based on the above embodiments, specifies the steps of determining the charging and discharging conditions corresponding to the energy storage unit, determining the state-of-charge conversion factor, calculating the comprehensive weight corresponding to the energy storage unit, allocating a single active power command to each energy storage unit, and other optional steps. In this embodiment, the method may include: S201. For each energy storage unit, determine whether the total active power command at the station level is greater than zero.

[0042] Specifically, for each energy storage unit, the charging and discharging conditions of the energy storage unit can be determined first based on the positive or negative sign of the station-level total active power command. Therefore, when the station-level total active power command is greater than zero (positive sign), S202 can be executed; when the station-level total active power command is less than zero, S203 can be executed; and when the station-level total active power command is equal to zero or within the dead zone, S204 can be executed.

[0043] S202. If the total active power command at the station level is greater than zero, then the charging and discharging condition corresponding to the energy storage unit is determined to be the discharging condition.

[0044] Specifically, if the total active power command at the station level is greater than zero, then it can be determined that the station is in a discharge condition.

[0045] S203. If the total active power command at the station level is less than zero, then the charging and discharging condition corresponding to the energy storage unit is determined to be the charging condition.

[0046] Specifically, if the station-level total available power command is less than zero, then it can be determined that the station is in charging condition.

[0047] S204. If the total active power command at the station level is equal to zero or the state of charge corresponding to the energy storage unit is in the dead zone, then the charging and discharging condition corresponding to the energy storage unit is determined to be the zero-state condition.

[0048] Among them, the zero-voltage operating condition is actually called the grid-type zero active voltage frequency support operating condition.

[0049] Specifically, if the total active power command at the station level is zero, or the state of charge of the energy storage unit is within the dead zone, then the charging and discharging condition can be determined as a zero-state condition. In this case, the energy storage unit cannot regulate its charge through active power charging and discharging, and the active power command is directly set to zero. Therefore, when the charging and discharging condition corresponding to the energy storage unit is determined to be a zero-state condition, the energy storage unit does not participate in the power allocation described below.

[0050] In this embodiment, the charging and discharging conditions and whether the energy storage unit is in a zero-state condition can be determined based on the relationship between the station-level total active power command and the zero value. This lays the foundation for calculating the state of charge conversion factor corresponding to each energy storage unit under different conditions, so that the power allocated to each energy storage unit based on the state of charge conversion factor is closer to the current operating condition requirements.

[0051] S205. Determine the exit threshold and full participation threshold based on the charging and discharging conditions, and determine the segmented formula for the state of charge conversion factor under the charging and discharging conditions based on the exit threshold, full participation threshold and the state of charge of the energy storage unit.

[0052] The exit threshold is the ultimate safety boundary at which an energy storage unit, upon reaching its state of charge boundary, is prohibited from continuing unidirectional charging / discharging, gradually reduces active power output, and eventually blocks active power commands, thus exiting full power regulation services. The full participation threshold is the state of charge boundary value that enables the unit to respond to upper-level active / reactive power dispatch commands without restriction and to fully participate in power regulation, frequency regulation, and voltage regulation services.

[0053] Specifically, based on the charging and discharging conditions, the corresponding state of charge (SOC) conversion factor segmentation formula can be selected first. Then, by using the exit threshold and the full participation threshold, the SOC range of the energy storage unit can be determined, and the corresponding SOC conversion factor segmentation formula can be determined.

[0054] For example, the exit threshold and the full participation threshold are determined based on the charge and discharge conditions, and the piecewise formula for the state of charge (SBC) conversion factor under the charge and discharge conditions is determined based on the exit threshold, the full participation threshold, and the SBC of the energy storage unit, including: (i) If the charging and discharging condition is the discharging condition, the discharging interval sub-formula is determined from the discharging exit threshold, the discharging full participation threshold, and the state of charge conversion coefficient segment formula based on the state of charge.

[0055] Among them, the discharge interval formula is determined from the segmented formula of the charge state conversion coefficient corresponding to the discharge condition based on the segmented range of the charge state.

[0056] Specifically, under discharge conditions, the segmented formula for the charge state conversion factor uses the segmented formula for the discharge charge state conversion factor. Furthermore, since the segmented interval range (segment range) of the segmented formula is determined by comparing the discharge charge state with the discharge exit threshold and the discharge full participation threshold, the corresponding discharge interval formula can be determined based on which segmented range the discharge charge state belongs to.

[0057] For example, the piecewise formula for the charge state reduction factor can be expressed as follows: ; Where, ki,dis Here is the charge conversion factor for the i-th energy storage unit; SOC i The state of charge (SOC) of the i-th energy storage unit. d,min The discharge exit threshold; SOC d,max The threshold for full participation in discharge.

[0058] Referring to the above formula, if the state of charge of the energy storage unit is less than or equal to the discharge exit threshold, then the discharge interval formula corresponding to its discharge charge conversion factor is k. i,dis =0, and the same applies to the others.

[0059] (ii) If the charging and discharging condition is the charging condition, the charging interval sub-formula is determined from the charging exit threshold, the charging full participation threshold, and the state of charge conversion coefficient segment formula.

[0060] Specifically, under charging conditions, the segmented formula for the state of charge conversion factor uses the segmented formula for the charging state of charge conversion factor. Furthermore, since the segmented interval range (segmented range) of the segmented formula is determined by comparing the charging state of charge with the charging exit threshold and the charging full participation threshold, the corresponding charging interval formula can be determined based on which segmented range the charging state of charge belongs to.

[0061] For example, the piecewise formula for the charging state of charge conversion factor can be expressed as follows: ; Where, k i,ch Here is the charge conversion factor for the i-th energy storage unit; SOC c,min For full participation in charging; SOC c,max The charging exit threshold.

[0062] Referring to the above formula, if the state of charge of the energy storage unit is less than or equal to the full participation threshold for charging, then the discharge interval formula corresponding to its discharge charge conversion factor is k. i,ch =1, and the others are the same.

[0063] In this embodiment, independent State of Charge (SOC) threshold ranges are set for charging and discharging, and piecewise linear conversion factors are used. During discharging, energy storage units with an SOC below the lower discharge threshold stop discharging or significantly reduce their discharge, while energy storage units with an SOC in the transition range participate in power sharing according to a linear coefficient, and energy storage units with a higher SOC participate in discharging normally. During charging, energy storage units with an SOC above the upper charging threshold stop charging or significantly reduce their charging, while energy storage units with an SOC in the transition range participate in power sharing according to a linear coefficient, and energy storage units with a lower SOC participate in charging normally. In this way, each energy storage unit can be reasonably allocated active power with a quantified conversion factor based on its actual SOC and its corresponding full participation and exit thresholds under charging and discharging conditions.

[0064] S206. Substitute the exit threshold, full participation threshold and state of charge into the piecewise formula for the state of charge reduction factor to calculate the state of charge reduction factor.

[0065] Specifically, once the interval formula corresponding to the current state of charge of the energy storage unit under the current operating conditions is determined, the state of charge conversion factor corresponding to the energy storage unit can be calculated according to the interval formula.

[0066] S207. When it is determined that the charging and discharging conditions of the energy storage unit are not zero-load conditions, calculate the product of the available capacity and the state of charge conversion factor to obtain the comprehensive weight of the energy storage unit.

[0067] The available capacity is the total effective energy storage that the energy storage unit can safely, stably, and controllably release (discharge) or absorb (charge) to the outside world.

[0068] Specifically, for the energy storage units participating in this round of regulation, their corresponding available capacity can be multiplied by the state of charge conversion factor to obtain the comprehensive weight of the energy storage unit.

[0069] For example, in one implementation, for the energy storage unit participating in this round of regulation, under discharge conditions, k i,dis The charge conversion factor is used, therefore its overall weight w i =E i ×k i,dis ; and under charging conditions, k i,ch The charge conversion factor is used, therefore its overall weight w i =E i ×k i,ch Among them, E iThe available capacity corresponding to the energy storage unit can be the rated capacity, the current available capacity, or the equivalent available capacity corrected according to the State of Health (SOH). Alternatively, if the energy storage unit is in an unavailable state, such as when its charging / discharging condition is at zero, its overall allocation weight is set to zero.

[0070] In this embodiment, compared with simply allocating according to capacity ratio, the comprehensive weight introduces dynamic SOC correction based on available capacity, which enables energy storage units in different SOC states to undertake different power shares.

[0071] Alternatively, when it is necessary to consider differences in battery aging, E can be... i Replace with equivalent available capacity, calculated as: E i,eq =E i ×SOH i In this way, energy storage units with higher aging levels and lower available energy can automatically reduce their power sharing ratio. This variation of the power limit still belongs to the adaptive coordinated control concept of the combined effect of capacity ratio and SOC conversion factor.

[0072] S208. Based on the total active power command at the station level, the sum of the comprehensive weights corresponding to all energy storage units, and the comprehensive weight corresponding to each energy storage unit, the total active power command at the station level is normalized and allocated to obtain the initial active power command corresponding to each energy storage unit.

[0073] The initial active power command is the first active power command allocated to each energy storage unit, without considering whether the energy storage unit can fully handle the active power.

[0074] Specifically, after calculating the comprehensive weight of each energy storage unit participating in this round of regulation, the total active power can be initially normalized and allocated. Therefore, for each energy storage unit, the initial active power command that the energy storage unit should have undertaken from the station-level total active power command can be determined based on the comprehensive weight of the energy storage unit and the sum of the comprehensive weights of all energy storage units.

[0075] For example, the total active power command at the station level is normalized and allocated to obtain the initial active power command corresponding to each energy storage unit, which can be calculated according to the following formula: ; Among them, P i 0 The initial active power command is determined for energy storage unit i participating in the adjustment in the initial round 0. In this embodiment, in non-initial rounds, the "initial active power command" for energy storage unit i in each round n is P. i n P∑ In the initial round 0, the command is the total active power at the station level; in subsequent rounds, it is the remaining power to be allocated in each round. i Let ∑w be the comprehensive weight corresponding to energy storage unit i; ∑w is the sum of the weights of all energy storage units participating in this round of regulation; in practice, the summation range is the energy storage units participating in this round of regulation whose comprehensive weight is greater than zero.

[0076] Optionally, if the sum of the overall weights of all energy storage units is zero, it means that no energy storage unit currently meets the charging and discharging conditions in that direction. The centralized coordination controller can reduce the total active power command to zero, return an insufficient available power signal to the upper-level controller, or enter the protection mode according to the preset strategy.

[0077] S209. For each energy storage unit, determine the allowable active power value based on the initial active power command and the upper limit of the allowable active power of the energy storage unit, and determine the limit power of the energy storage unit after power limiting based on the total active power command and the allowable active power value at the station level.

[0078] The permissible upper limit of active power is the maximum permissible active power that can be stably absorbed (charged) or output (discharged) per unit time. The permissible active power value is the active power that the energy storage unit can actually handle. The limit power is the actual active power command that the energy storage unit can handle after power limiting.

[0079] Specifically, since each energy storage unit has a corresponding upper limit of allowed active power in practice, and the initial active power calculated above may exceed the upper limit of allowed active power of a certain energy storage unit, causing errors in power allocation, for each energy storage unit, it is necessary to compare the initial active power command with the upper limit of allowed active power to determine the allowed active power value, and then determine the limit power after power limiting based on it.

[0080] For example, the allowable active power value is determined based on the initial active power command and the upper limit of allowable active power of the energy storage unit, and the limit power of the energy storage unit after power limiting is determined based on the total active power command and the allowable active power value at the station level, including: (i) The minimum value between the initial active power command of the energy storage unit and the upper limit of the allowed active power shall be used as the allowed active power value.

[0081] Specifically, regarding the initial active power command and the upper limit of allowable active power, the two can be compared, and the minimum value can be taken as the allowable active power value, i.e.: min(|P i 0 |,P i，max ).

[0082] (ii) Substitute the station-level total active power command into the sign function to obtain the power direction, and combine the power direction with the active power allowable value to obtain the limit power of the energy storage unit after power limiting.

[0083] The sign function is a piecewise function used to characterize the positive or negative attribute of a real number. In this embodiment, the sign function is mainly used to determine the charging and discharging direction of the energy storage active power command, serving as an interval determination identifier for the piecewise control logic. The power direction is the charging and discharging direction.

[0084] Specifically, after calculating the allowable active power value, the station-level active power command can be substituted into the symbol function to determine the power direction, and the power direction can be used as the mathematical symbol of the allowable active power value to obtain the limit power of the energy storage unit after power limiting.

[0085] For example, the power limit of an energy storage unit after power limiting can be determined according to the following formula: ; S210: Calculate the difference between the total active power command at the station level and the limit power and value of all energy storage units after power limiting, obtain the remaining power to be allocated, and remove energy storage units whose limit power after power limiting is equal to the upper limit of allowed active power.

[0086] Among them, the limit power sum is the sum of the limit power of all energy storage units after power limiting.

[0087] Specifically, after determining the limit power for each energy storage unit that can participate in this round of regulation, since the sum of the limit power values ​​for all energy storage units may be less than or equal to the active power required by the station-level total active power command, it is necessary to further determine the difference. That is, by subtracting the sum of the limit power values ​​from the active power corresponding to the station-level total active power command, the remaining power to be allocated is obtained. At the same time, for energy storage units whose limit power after power limiting in this round is equal to the upper limit of the allowed active power, since the power they can actually undertake is zero, they can be eliminated. This is equivalent to their final allocated limit power being their corresponding single active power command.

[0088] S211. Determine whether the remaining power to be allocated has been reduced to zero; if not, proceed to S212; if yes, proceed to S213.

[0089] Specifically, it can be determined whether the remaining power to be allocated has returned to zero. If not, it means that the remaining power to be allocated still needs to be further allocated to the energy storage units that have not been eliminated and can continue to undertake the allocation of active power. Therefore, S212 is executed. If the remaining power to be allocated has returned to zero, it is determined that the current allocation is over and S213 can be executed.

[0090] S212. Take the remaining power to be allocated as the station-level total active power command; return to execute S207.

[0091] Specifically, if it is determined that the remaining power to be allocated is not zero, the remaining power to be allocated may be taken as the total active power command of the next round. That is, assuming the current round is "0", the next round is calculated according to the above formula, where "0" is changed to "1", the station-level total active power command in the above formula is changed to the remaining power to be allocated, and the comprehensive weight is re-determined for the energy storage unit i (the non-eliminated energy storage unit) participating in regulation in the current round. At this time, in the calculation formula of the comprehensive weight, E i may be the current available capacity of the energy storage unit (that is, the rated capacity minus the capacity corresponding to the power already allocated to it in the previous rounds).

[0092] S213. Take the sum of all limited power allocated to each energy storage unit as the single active power command allocated to the energy storage unit, and allocate the single active power command to each energy storage unit.

[0093] Specifically, since the number of rounds in which each energy storage unit participates in allocation may be different according to the above steps, for each energy storage unit, the sum of all limited power allocated to it in all rounds may be taken as the single active power command allocated to the energy storage unit, and the single active power command is allocated to each energy storage unit.

[0094] In this embodiment, a coordinated control process with single-unit power limiting and remaining power reallocation is proposed. That is, when a certain energy storage unit cannot continue to bear the allocated power due to the limitation of rated power, SOC threshold or operating state, the power of the unit is limited within the allowable range, and the unallocated power is continuously allocated among the remaining available energy storage units according to the comprehensive weight, which improves the tracking capability of the total active power command. At the same time, this method is compatible with the local virtual synchronous generator control, droop control, virtual inertia and damping control of grid-forming energy storage converters, and only generates the active power reference value or power offset for each unit. Each grid-forming energy storage can still maintain the grid-forming control characteristic locally without changing its voltage-source operation mechanism. Further, the threshold interval, SOC conversion coefficient and power limiting strategy can be adjusted according to different application scenarios, which can be used not only for grid-connected active power support of energy storage power stations, but also for multi-unit coordinated operation of energy storage supporting new energy stations.

[0095] Figure 3 is a structural diagram of a power allocation apparatus for energy storage units provided by an embodiment of the present invention, as shown in Figure 3 shown in the figure, the apparatus includes: A state determination module 301, configured to determine, for each energy storage unit, a corresponding charging / discharging working condition of the energy storage unit according to a station-level total active power command, and determine a state of charge conversion coefficient according to the charging / discharging working condition and the state of charge of the energy storage unit.

[0096] The calculation module 302 is used to calculate the comprehensive weight of the energy storage unit based on the state of charge conversion factor and the available capacity of the energy storage unit.

[0097] The allocation module 303 is used to allocate a single active power instruction to each energy storage unit based on the total active power instruction at the station level, the comprehensive weight corresponding to all energy storage units, and the active power limit corresponding to each energy storage unit.

[0098] Based on the above embodiments, the charging and discharging conditions corresponding to the energy storage unit are determined according to the station-level total active power command. The state determination module 301 is specifically used for: Determine if the station-level total active power command is greater than zero; if the station-level total active power command is greater than zero, then determine the charging / discharging condition corresponding to the energy storage unit as the discharging condition; if the station-level total active power command is less than zero, then determine the charging / discharging condition corresponding to the energy storage unit as the charging condition; if the station-level total active power command is equal to zero or the state of charge corresponding to the energy storage unit is in the dead zone, then determine the charging / discharging condition corresponding to the energy storage unit as the zero-state condition.

[0099] Based on the above embodiments, the state of charge (SOC) conversion factor is determined according to the charging and discharging conditions and the SOC of the energy storage unit. Specifically, the SOC determination module 301 is used for: The exit threshold and full participation threshold are determined based on the charging and discharging conditions. The state of charge (SCC) conversion factor under the charging and discharging conditions is then determined based on the exit threshold, full participation threshold, and SCC of the energy storage unit. The SCC conversion factor is calculated by substituting the exit threshold, full participation threshold, and SCC into the SCC conversion factor piecewise formula.

[0100] Based on the above embodiments, the exit threshold and full participation threshold are determined according to the charging and discharging conditions, and the segmented formula for the state of charge conversion factor under the charging and discharging conditions is determined according to the exit threshold, the full participation threshold, and the state of charge of the energy storage unit. The state determination module 301 is specifically used for: If the charging / discharging condition is a discharging condition, the discharging interval sub-formula is determined from the piecewise formula of the state of charge conversion factor based on the discharging exit threshold, the discharging full participation threshold, and the state of charge. If the charging / discharging condition is a charging condition, the charging interval sub-formula is determined from the piecewise formula of the state of charge conversion factor based on the charging exit threshold, the charging full participation threshold, and the state of charge.

[0101] Based on the above embodiments, the comprehensive weight corresponding to the energy storage unit is calculated according to the state of charge conversion factor and the available capacity of the energy storage unit. The calculation module 302 is specifically used for: When the charging and discharging conditions of the energy storage unit are not zero-load conditions, the product of the available capacity and the state of charge conversion factor is calculated to obtain the comprehensive weight of the energy storage unit.

[0102] Based on the above embodiments, according to the station-level total active power command, the comprehensive weight corresponding to all energy storage units, and the active power limit corresponding to each energy storage unit, a single active power command is allocated to each energy storage unit. The allocation module 303 is specifically used for: The station-level total active power command is normalized and allocated based on the sum of the comprehensive weights corresponding to all energy storage units and the comprehensive weight corresponding to each energy storage unit, resulting in the initial active power command for each energy storage unit. For each energy storage unit, the allowable active power value is determined based on the initial active power command and the upper limit of the allowable active power, and the limit power of the energy storage unit after power limiting is determined based on the station-level total active power command and the allowable active power value. The difference between the station-level total active power command and the sum of the limit power values ​​of all energy storage units after power limiting is calculated. The remaining power to be allocated is obtained, and energy storage units whose limit power after power limiting is equal to the upper limit of allowed active power are eliminated; the remaining power to be allocated is used as the station-level total active power command, and the steps of normalizing and allocating the station-level total active power command according to the station-level total active power command, the sum of the comprehensive weights corresponding to all energy storage units, and the comprehensive weights corresponding to each energy storage unit are returned to be executed until it is determined that the remaining power to be allocated is zero. All the limit power allocated to each energy storage unit is used as the single active power command allocated to the energy storage unit, and a single active power command is allocated to each energy storage unit.

[0103] Based on the above embodiments, the allowable active power value is determined according to the initial active power command and the upper limit of the allowable active power of the energy storage unit, and the limit power of the energy storage unit after power limiting is determined according to the total active power command at the station level and the allowable active power value. The allocation module 303 is specifically used for: The minimum of the initial active power command and the upper limit of the allowed active power of the energy storage unit is taken as the allowable active power value; the total active power command at the station level is substituted into the sign function to obtain the power direction, and the power direction is combined with the allowable active power value to obtain the limit power of the energy storage unit after power limiting.

[0104] The power distribution device for the energy storage unit provided in the embodiments of the present invention can execute the power distribution method for the energy storage unit provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of executing the method.

[0105] It is worth noting that in the embodiments of the power distribution device of the above-mentioned energy storage unit, the various units and modules included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be realized; in addition, the specific names of each functional unit are only for easy differentiation and are not used to limit the scope of protection of the present invention.

[0106] Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Figure 4 A block diagram is shown of an exemplary electronic device 11 suitable for implementing embodiments of the present invention. Figure 4 The electronic device 11 shown is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of the present invention.

[0107] like Figure 4 As shown, the electronic device 11 is represented in the form of a general-purpose computing electronic device. The components of the electronic device 11 may include, but are not limited to: one or more processors or processing units 16, system memory 28, and bus 18 connecting different system components (including system memory 28 and processing unit 16).

[0108] Bus 18 represents one or more of several bus architectures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processor, or a local bus using any of the various bus architectures. For example, these architectures include, but are not limited to, the Industry Standard Architecture (ISA) bus, the Micro Channel Architecture (MAC) bus, the Enhanced ISA bus, the Video Electronics Standards Association (VESA) local bus, and the Peripheral Component Interconnect (PCI) bus.

[0109] Electronic device 11 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by electronic device 11, including volatile and non-volatile media, removable and non-removable media.

[0110] System memory 28 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and / or cache memory 32. Electronic device 11 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, storage system 34 may be used to read and write non-removable, non-volatile magnetic media (… Figure 4 Not shown; usually referred to as a "hard drive"). Although Figure 4 As not shown, disk drives for reading and writing to removable non-volatile disks (e.g., "floppy disks") and optical disc drives for reading and writing to removable non-volatile optical discs (e.g., CD-ROMs, DVD-ROMs, or other optical media) may be provided. In these cases, each drive may be connected to bus 18 via one or more data media interfaces. System memory 28 may include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of the embodiments of the present invention.

[0111] A program / utility 40 having a set (at least one) of program modules 42 may be stored, for example, in system memory 28. Such program modules 42 include, but are not limited to, an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include an implementation of a network environment. Program modules 42 typically perform the functions and / or methods described in the embodiments of the present invention.

[0112] Electronic device 11 can also communicate with one or more external devices 14 (e.g., keyboard, pointing device, display 24, etc.), and with one or more devices that enable a user to interact with electronic device 11, and / or with any device that enables electronic device 11 to communicate with one or more other computing devices (e.g., network card, modem, etc.). This communication can be performed via input / output (I / O) interface 22. Furthermore, electronic device 11 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 20. Figure 4 As shown, network adapter 20 communicates with other modules of electronic device 11 via bus 18. It should be understood that, although... Figure 4 As not shown, other hardware and / or software modules may be used in conjunction with electronic device 11, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0113] The processing unit 16 executes various functional applications and page displays by running programs stored in the system memory 28, such as implementing the power allocation method for the energy storage unit provided in this embodiment. Of course, those skilled in the art will understand that the processor can also implement the technical solutions of the power allocation method for the energy storage unit provided in any embodiment of the present invention.

[0114] This invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements, for example, the power allocation method for an energy storage unit provided in this invention. The computer storage medium of this invention can be any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0115] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0116] Program code contained on a computer-readable medium may be transmitted using any suitable medium, including but not limited to: wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0117] This invention also provides a computer program product, including a computer program that, when executed by a processor, implements the power distribution method for an energy storage unit as provided in any embodiment of this invention.

[0118] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof. Programming languages ​​include object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages—such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0119] Those skilled in the art will understand that the modules or steps of the present invention described above can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Optionally, they can be implemented using computer-executable program code, thereby allowing them to be stored in a storage device for execution by a computing device, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the present invention is not limited to any particular combination of hardware and software.

[0120] Furthermore, the acquisition, storage, use, and processing of data in the technical solution of this invention all comply with the relevant provisions of national laws and regulations.

[0121] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A power distribution method for an energy storage unit, characterized in that, The method includes: For each energy storage unit, the charging and discharging conditions corresponding to the energy storage unit are determined according to the total active power command at the station level, and the state of charge conversion factor is determined according to the charging and discharging conditions and the state of charge of the energy storage unit. The comprehensive weight of the energy storage unit is calculated based on the state of charge conversion factor and the available capacity of the energy storage unit. Based on the total active power command at the station level, the comprehensive weights corresponding to all energy storage units, and the active power limit corresponding to each energy storage unit, a single active power command is allocated to each energy storage unit.

2. The method according to claim 1, characterized in that, The step of determining the charging and discharging conditions corresponding to the energy storage unit based on the station-level total active power command includes: Determine whether the total active power command at the station level is greater than zero; If the total active power command at the station level is greater than zero, then the charging and discharging condition corresponding to the energy storage unit is determined to be the discharging condition. If the total active power command at the station level is less than zero, then the charging and discharging condition corresponding to the energy storage unit is determined to be the charging condition. If the total active power command at the station level is equal to zero or the state of charge corresponding to the energy storage unit is in the dead zone, then the charging and discharging condition corresponding to the energy storage unit is determined to be the zero-state condition.

3. The method according to claim 1, characterized in that, The step of determining the state of charge (SCC) conversion factor based on the charging and discharging conditions and the SCC of the energy storage unit includes: The exit threshold and the full participation threshold are determined based on the charging and discharging conditions, and the state of charge conversion factor segmentation formula under the charging and discharging conditions is determined based on the exit threshold, the full participation threshold and the state of charge of the energy storage unit. The exit threshold, the full participation threshold, and the state of charge are substituted into the piecewise formula of the state of charge reduction factor to calculate the state of charge reduction factor.

4. The method according to claim 3, characterized in that, The step of determining the exit threshold and the full participation threshold based on the charging and discharging conditions, and determining the piecewise formula for the state of charge (SBC) conversion factor under the charging and discharging conditions based on the exit threshold, the full participation threshold, and the SBC of the energy storage unit, includes: If the charging / discharging condition is a discharging condition, then the discharging interval sub-formula is determined from the piecewise formula of the state of charge conversion coefficient based on the discharging exit threshold, the discharging full participation threshold, and the state of charge. If the charging / discharging condition is a charging condition, then the charging interval sub-formula is determined from the piecewise formula of the state of charge conversion factor based on the charging exit threshold, the charging full participation threshold, and the state of charge.

5. The method according to claim 2, characterized in that, The step of calculating the comprehensive weight corresponding to the energy storage unit based on the state of charge conversion factor and the available capacity of the energy storage unit includes: When it is determined that the charging and discharging condition of the energy storage unit is not the zero-condition, the product of the available capacity and the state of charge conversion factor is calculated to obtain the comprehensive weight corresponding to the energy storage unit.

6. The method according to claim 1, characterized in that, The method of allocating a single active power instruction to each energy storage unit based on the total active power instruction at the station level, the comprehensive weight corresponding to all energy storage units, and the active power limit corresponding to each energy storage unit includes: The station-level total active power command is normalized and allocated based on the sum of the comprehensive weights corresponding to all energy storage units and the comprehensive weights corresponding to each energy storage unit, so as to obtain the initial active power command corresponding to each energy storage unit. For each energy storage unit, the allowable active power value is determined based on the initial active power command and the upper limit of the allowable active power of the energy storage unit, and the limit power of the energy storage unit after power limiting is determined based on the total active power command at the station level and the allowable active power value. Calculate the difference between the total active power command at the station level and the limit power and value of all energy storage units after power limiting to obtain the remaining power to be allocated, and remove the energy storage units whose limit power after power limiting is equal to the upper limit of the allowed active power. The remaining power to be allocated is used as the station-level total active power command. The process returns to the step of normalizing and allocating the station-level total active power command based on the station-level total active power command, the sum of the comprehensive weights corresponding to all energy storage units, and the comprehensive weights corresponding to each energy storage unit, until it is determined that the remaining power to be allocated is zero. All the limit power allocated to each energy storage unit is used as the single active power command allocated to the energy storage unit, and a single active power command is allocated to each energy storage unit.

7. The method according to claim 6, characterized in that, The step of determining the allowable active power value based on the initial active power command and the upper limit of allowable active power of the energy storage unit, and determining the limit power of the energy storage unit after power limiting based on the total active power command at the station level and the allowable active power value, includes: The minimum value between the initial active power command of the energy storage unit and the upper limit of the allowed active power is taken as the allowed active power value. The total active power command at the station level is substituted into the sign function to obtain the power direction, and the power direction is combined with the active power allowable value to obtain the limit power of the energy storage unit after power limiting.

8. A power distribution device for an energy storage unit, characterized in that, The device includes: The status determination module is used to determine the charging and discharging conditions of each energy storage unit according to the station-level total active power command, and to determine the state of charge conversion factor according to the charging and discharging conditions and the state of charge of the energy storage unit. The calculation module is used to calculate the comprehensive weight corresponding to the energy storage unit based on the state of charge conversion factor and the available capacity of the energy storage unit; The allocation module is used to allocate a single active power command to each energy storage unit based on the total active power command at the station level, the comprehensive weight corresponding to all energy storage units, and the active power limit corresponding to each energy storage unit.

9. An electronic device, characterized in that, include: One or more processors; Memory, used to store one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors implement the power distribution method of the energy storage unit as described in any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the power distribution method of the energy storage unit as described in any one of claims 1 to 7.

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