A method for distributing charging and discharging power in an energy storage station

Abstract

The present invention discloses a method for distributing charging and discharging power for an energy storage station, which belongs to the technical field of energy storage in a new energy power system, and includes obtaining a dispatch instruction issued by a dispatch center; judging the dispatch instruction; if the dispatch instruction is a charging instruction, executing a consistent charging power distribution algorithm or a differential charging power distribution algorithm to reallocate power to the energy storage container; if the dispatch instruction is a discharging instruction, executing a consistent discharging power distribution algorithm or a differential discharging power distribution algorithm to reallocate power to the energy storage container. The present invention solves the problem that when the current SOCs of the energy storage containers in an energy storage station are different, the command power cannot be evenly distributed according to the differences in the current SOCs of the energy storage containers; and when the maximum charging power and the maximum discharging power of the energy storage containers in the energy storage station are inconsistent, the command power cannot be evenly distributed according to the differences in the current maximum charging power and the maximum discharging power of the energy storage containers.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage in new energy power systems, and in particular to a method for distributing charging and discharging power in an energy storage station. Background Art

[0002] As renewable energy generation capacity continues to expand, its proportion in the power grid is increasing. However, due to the small capacity of individual units, the large number of units, the dispersed distribution of renewable energy generation, and the significant intermittent, volatile, and random characteristics of renewable energy generation, the integration of a high proportion of renewable energy into the grid will inevitably bring unprecedented challenges to the power system's supply and demand balance, as well as its safe and stable control. Energy storage systems are crucial for regulating the imbalance between renewable energy generation and the power system, as well as the instability of voltage and power. Providing stable voltage and power has become a pressing challenge for energy storage systems.

[0003] Currently, traditional renewable energy power stations have the following shortcomings: 1. When the energy storage station transmits power, it is unable to allocate power based on the current SOC (State of Charge) of the energy storage container; 2. When the energy storage containers in the energy storage station have different charging and discharging power limits due to static reasons (using cascade batteries, different battery procurement specifications) or dynamic reasons (maintenance, battery degradation), power cannot be allocated based on the differences in the charging and discharging power limits of each energy storage container.

[0004] Based on this, the present invention provides a method for allocating charging and discharging power for an energy storage station to solve the above problems. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the present invention provides a method for distributing charging and discharging power in an energy storage station.

[0006] The technical solution of the present invention to solve the above technical problems is as follows:

[0007] A method for distributing charging and discharging power at an energy storage station, comprising the following steps:

[0008] S1: Obtaining a dispatch instruction issued by a dispatch center, wherein the dispatch instruction includes a charging instruction and a discharging instruction;

[0009] S2: Determine the scheduling instruction;

[0010] S21: If the dispatch instruction is a charging instruction, execute the consistent charging power allocation algorithm or the differentiated charging power allocation algorithm to reallocate power to the energy storage container;

[0011] S22: If the dispatch instruction is a discharge instruction, a consistent discharge power allocation algorithm or a differential discharge power allocation algorithm is executed to reallocate power to the energy storage container.

[0012] An energy storage container adopts the method for distributing charging and discharging power for an energy storage station, and all energy storage containers using this method have the same maximum charging power and the same maximum discharging power.

[0013] An energy storage container adopts the method for allocating charging and discharging power for an energy storage station. The maximum charging power and the maximum discharging power of all energy storage containers using this method are consistent or inconsistent, and the method supports dynamic changes in the maximum charging power and the maximum discharging power of the energy storage containers.

[0014] Compared with the prior art, the beneficial effects of the invention are:

[0015] (1) It solves the problem that when the maximum charge and discharge powers of the energy storage containers are inconsistent, the command power cannot be evenly distributed according to the difference in the current maximum charge and discharge powers of the energy storage containers; it can solve the problem of unbalanced charge and discharge power distribution when the current SOC of the energy storage containers is inconsistent;

[0016] (2) It solves the problem of low utilization rate of energy storage capacity of energy storage containers; it solves the problem that due to the difference in the current SOC of the energy storage containers, some energy storage containers reach over-discharge too early during discharge, and some energy storage containers reach overcharge too early during charging, resulting in a decrease in the overall maximum charging and discharging power of the energy storage station. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flow chart of the charging and discharging power allocation algorithm for consistent energy storage containers;

[0018] Figure 2 Flowchart of the charging and discharging power allocation algorithm for differentiated energy storage containers;

[0019] Figure 3 Schematic diagram of the current SOC of each energy storage container in the energy storage station;

[0020] Figure 4 A schematic diagram of the maximum total charging power of the selected energy storage container is drawn;

[0021] Figure 5 For Figure 4 Schematic diagram of connecting BC points for segmentation based on ;

[0022] Figure 6 For Figure 5 Based on the diagram, rotate the BC connecting line clockwise with point B as the center;

[0023] Figure 7 For Figure 6 A schematic diagram of the maximum charging power length interval of each energy storage container is marked on the basis of the selected energy storage container;

[0024] Figure 8 To use the greatest common divisor as the interval unit Figure 7 Schematic diagram of further segmentation based on ;

[0025] Figure 9 Schematic diagram of adding auxiliary lines to split intervals;

[0026] Figure 10 For Figure 5 Based on the diagram, rotate the BC connecting line clockwise with point C as the center;

[0027] Figure 11 For Figure 10 A schematic diagram of the maximum charging power length interval of each energy storage container is marked on the basis of the selected energy storage container;

[0028] Figure 12 To use the greatest common divisor as the interval unit Figure 11 Schematic diagram of further segmentation based on ;

[0029] Figure 13 Schematic diagram of adding auxiliary lines to split intervals;

[0030] Figure 14 In accordance with Figure 10 Draw the power distribution diagram;

[0031] Figure 15 For Figure 14 A schematic diagram showing the maximum charging power length interval of each energy storage container is marked on the basis of the above;

[0032] Figure 16 The interval unit is 500. Figure 15 Schematic diagram of further segmentation based on ;

[0033] Figure 17 A schematic diagram of the maximum total discharge power of the selected energy storage container is drawn;

[0034] Figure 18 For Figure 17 Schematic diagram of connecting BC points for segmentation based on ;

[0035] Figure 19 For Figure 18 Based on the diagram, rotate the BC connecting line clockwise with point B as the center;

[0036] Figure 20 For Figure 19 A schematic diagram of the maximum discharge power length interval of each energy storage container is marked and selected based on the above;

[0037] Figure 21 To use the greatest common divisor as the interval unit Figure 19 Schematic diagram of further segmentation based on ;

[0038] Figure 22 For Figure 18 Based on the diagram, rotate the BC connecting line clockwise with point C as the center;

[0039] Figure 23 For Figure 22 A schematic diagram of the maximum discharge power length interval of each energy storage container is marked and selected based on the above;

[0040] Figure 24 To use the greatest common divisor as the interval unit Figure 23 Schematic diagram of further segmentation based on ;

[0041] Figure 25 In accordance with Figure 20 Draw the power distribution diagram;

[0042] Figure 26 For Figure 25 On this basis, a schematic diagram is provided to mark the maximum power length interval of each energy storage container discharge;

[0043] Figure 27 To use 500 as the interval unit, split it again Figure 26 The resulting schematic diagram. DETAILED DESCRIPTION

[0044] The principles and features of the present invention are described below in conjunction with all the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0045] An embodiment of the present invention discloses a method for allocating charging and discharging power of an energy storage station.

[0046] Reference Figure 1-Figure 27 , a method for distributing charging and discharging power for an energy storage station, comprising the following steps:

[0047] S1: Obtaining a dispatch instruction issued by a dispatch center, wherein the dispatch instruction includes a charging instruction and a discharging instruction;

[0048] S2: Determine the scheduling instruction;

[0049] S21: If the dispatch instruction is a charging instruction, execute the consistent charging power allocation algorithm or the differentiated charging power allocation algorithm to reallocate power to the energy storage container;

[0050] S22: If the dispatch instruction is a discharge instruction, a consistent discharge power allocation algorithm or a differential discharge power allocation algorithm is executed to reallocate power to the energy storage container.

[0051] The present invention includes power allocation algorithms for consistent energy storage containers and differentiated energy storage containers. Consistent energy storage containers are defined as containers with consistent maximum charging and discharge powers. Differential energy storage containers are defined as containers with consistent or inconsistent maximum charging and discharge powers, and support dynamic changes in maximum charging and discharge powers.

[0052] The following describes the power allocation algorithm for consistent energy storage containers.

[0053] Assume that the number of energy storage containers in the energy storage station is N, and the maximum charging power UnitChargeLimitP and the maximum discharging power UnitDisChaLimitP of each energy storage container are the same. The maximum SOC limit of charging is SOC LimirUp ; The minimum SOC lower limit of discharge is SOC LimitDown The grouping step is F. The SOC value range is 0-100, the power Pinst is sent as the instruction, and the power calculation interval is Interval seconds.

[0054] This allocation mode includes two command power allocation algorithms: charging power allocation and discharging power allocation. The lower SOC limit for battery discharge and the upper SOC limit for battery charge can be flexibly configured based on the battery status of the energy storage station. The step size of the SOC grouping can be adjusted based on the ratio of the energy storage station's full-load total power to the issued command power. Furthermore, the frequency of power command issuance can be configured to determine whether to collect the current SOC of the energy storage container in real time and reallocate the command power.

[0055] Introduction to the consistent charging power allocation algorithm:

[0056] In S21, when executing the consistent charging power distribution algorithm, the following steps are specifically included:

[0057] S211: obtaining the current SOC of all energy storage containers during charging;

[0058] S212: Exclude the current SOC from being greater than SOC LimitUp (charging maximum SOC upper limit) energy storage container, the number of remaining selectable energy storage containers is n, n ≤ N;

[0059] S213: Group the n selectable energy storage containers according to the current SOC, with a grouping step of F and a grouping number of X, where X is rounded up to an integer, where X = SOC LimitUp / F, groups are sorted from low to high according to the SOC value range, and the group number range is 1, 2, ..., X;

[0060] S214: Calculate the total maximum charging power of each group of energy storage containers, and then accumulate the group maximum charging power in sequence from the group with a low SOC value range to the group with a high SOC value range, until the accumulated group maximum charging power ≥ the command power Pinst. At this time, the group participating in the accumulation is in the group selection range that meets the minimum power of the energy storage container under the command, and the maximum group number is set to X min , the number of groups not in the range is XX min , then the groups selected to participate in power allocation are 1~X min +(XX min ) / 2 rounded down;

[0061] If the accumulated maximum charging power of all groups is still less than the command power Pinst after all groups are accumulated, the optional energy storage container issues a command according to the maximum charging power of the energy storage container;

[0062] Specifically, 1 to X min In order to meet the minimum group range required by the command power, if the energy storage containers are selected according to the minimum range, the power value allocated to each energy storage container will be very large. In this way, the energy storage container with a higher current SOC will reach the upper limit prematurely, which will cause the overall maximum charging power of the energy storage station to decrease. When a high-power charging command is received, some power will be lost due to the decrease in the overall maximum charging power of the energy storage station; (XX min ) / 2 is half of the remaining number of groups, which means that a slightly larger number of groups are selected. Because the maximum charging power of the energy storage container is fixed, the current high SOC is based on this fixed maximum power reduction. The more energy storage containers selected provide space for allocating relatively small power to those energy storage containers with the current high SOC.

[0063] S215: The number of currently selected energy storage containers is nSelected, and the average power of each energy storage container is The selected energy storage containers are sorted from large to small according to the current SOC, and the power allocated to each energy storage container is an arithmetic progression.

[0064] If Pavg ≤ UnitChargeLimitP / 2, the power allocated to the energy storage container with the largest current SOC is 0. The number of elements in the arithmetic sequence is the number of currently selected energy storage containers, nSelected, with an average value of Pavg and a minimum value of 0. Calculate the values of each element in the arithmetic sequence, and then sort the energy storage containers according to the current SOC. The larger the current SOC, the smaller the allocated power, and allocate power to each energy storage container.

[0065] Assume that the common difference of the arithmetic progression is gc; the power values allocated to each energy storage container are arranged from large to small according to the current SOC, respectively:

[0066] 0, 0+1×gc, 0+2×gc,…, 0+(nSelected-1)gc.

[0067] Since the arithmetic progression (maximum value + minimum value) / 2 = average value, that is, (0+(nSelected-1)gc) / 2 = Pavg; (0+(nSelected-1)gc) / 2 = Pinst / nSelected;

[0068] Power tolerance gc=(2×Pinst) / (nSelected 2 -nSelected);

[0069] After calculating the tolerance gc, the value of the tolerance gc is substituted into the power formula of each energy storage container to obtain the charging power value allocated to each energy storage container.

[0070] If Pavg > UnitChargeLimitP / 2, the power allocated to the energy storage container with the lowest current SOC is the maximum charging power, UnitChargeLimitP. The number of elements in the arithmetic sequence is the number of currently selected energy storage containers, nSelected. The average value is Pavg, and the maximum value is UnitChargeLimitP. After calculating the values of the elements in the arithmetic sequence, the energy storage containers are sorted according to their current SOC, with the higher the current SOC, the lower the power allocated. This power is then allocated to each energy storage container.

[0071] Assume that the common difference of the arithmetic progression is gc; the power values allocated to each energy storage container are arranged from small to large according to the current SOC, which are:

[0072] UnitChargeLimitP, UnitChargeLimitP-1×gc,…, UnitChargeLimitP-(nSelected-1)×gc.

[0073] Since the arithmetic progression (maximum value + minimum value) / 2 = average value;

[0074] (UnitChargeLimitP+UnitChargeLimitP-(nSelected-1)×gc) / 2=Pavg;

[0075] (UnitChargeLimitP + UnitChargeLimitP - (nSelected - 1) × gc) / 2 = Pinst / nSelected; the power tolerance gc is calculated as follows:

[0076] gc=(2×(UnitChargeLimitP×nSelected-Pinst)) / (nSelected 2 -nSelected);

[0077] After calculating the tolerance gc, the value of the tolerance gc is substituted into the power formula of each energy storage container to obtain the charging power value allocated to each energy storage container.

[0078] If no new power command is received after waiting for Interval seconds, the current SOC of the energy storage container is re-collected, the above calculation is repeated, and power is reallocated to each container (when Interval is less than 0, the power recalculation logic is not executed).

[0079] The algorithm is further explained below through specific examples and in conjunction with the accompanying drawings.

[0080] For example, the current energy storage station contains 20 energy storage containers, and the maximum charging and discharging power of each energy storage container is 1000w. Figure 3 The current SOC of each storage container at the energy storage station. The upper limit of the storage container charging SOC is 90%, the lower limit of the discharge SOC is 10%, the SOC grouping step is 10, the commanded charging power is 4000w, and the power calculation interval is set to 30s.

[0081] During charging, based on the upper limit of the charging SOC, energy storage containers with an SOC greater than 90% are first excluded. Then, based on the current SOC of the energy storage container, the containers are grouped in steps of 10 (since the current SOC is higher than 90% and is excluded, the current SOC range of the energy storage container is 0% to 90%), for a total of 9 groups. The groups are arranged in order from low to high according to the SOC value range, as shown in Table 1 below:

[0082] Table 1 Energy storage container grouping

[0083]

[0084] After grouping, the total maximum charging power of each group of energy storage containers is calculated, and then the group maximum charging power is accumulated in sequence from the group with a low SOC value range to the group with a high SOC value range, until the accumulated group maximum charging power is greater than or equal to the command power. According to the grouping in the table, groups 1-2 just meet the instruction requirements, and the maximum group number is 2. At this time, according to the formula 2 + (9-2) / 2, rounded down to 5, it can be concluded that the selection range is groups 1-5, including EC_1, EC_2, EC_3, EC_4, EC_5, EC_6, EC_7, EC_8, EC_9, EC_10, a total of 10 energy storage containers. According to the current SOC, they are rearranged from low to high as EC_2, EC_1, EC_3, EC_4, EC_5, EC_6, EC_8, EC_7, EC_10, EC_9. The average charging power per container is 400W. Because the average power of 400W is ≤ the maximum charging power of the energy storage container 1000W / 2, the power allocated to EC_9 with the highest current SOC is 0. The average value of the arithmetic progression is 400W, and the minimum value is 0. The number of energy storage containers is 10.

[0085] Use the formula gc=(2×Pinst) / (nSelected 2 -nSelected)=(2×4000) / (10 2 -10)=800 / 9;

[0086] According to the energy storage containers sorted from high to low, the corresponding power calculation formula for each energy storage container (retain two decimal places) is as follows:

[0087] EC_9: 0; EC_10: 0+1×gc=88.89; EC_7: 0+2×gc=177.89;

[0088] EC_8: 0+3×gc=266.89; EC_6: 0+4×gc=355.89; EC_5: 0+5×gc=444.89;

[0089] EC_4: 0+6×gc=533.89; EC_3: 0+7×gc=622.89; EC_1: 0+8×gc=711.89;

[0090] EC_2: 0+9×gc=800;

[0091] According to the current SOC sorting, the corresponding values of the power delivered by the container are:

[0092] EC_1:711.89W; EC_2:800W; EC_3:622.89W; EC_4:533.89W;

[0093] EC_5:444.89W; EC_6:355.89W; EC_7:177.89W; EC_8:266.89W;

[0094] EC_9: 0W; EC_10: 88.89W;

[0095] The timer starts after the power command is issued. If a new power command is received within 30 seconds, the consistent charging or discharging power distribution calculation step is executed to distribute power to each container, and the timer is reset. If no new power command is received after 30 seconds, the power distribution step is executed again based on the latest current SOC of the energy storage container, and power is re-allocated to each container, and the timer is reset.

[0096] The consistent discharge power allocation algorithm is described as follows:

[0097] In S22, when executing the consistent discharge power allocation algorithm, the following steps are specifically included:

[0098] S221: obtaining the current SOC of all energy storage containers during discharge;

[0099] S222: Exclude the current SOC from being less than SOC LimitDown (discharge minimum SOC lower limit) energy storage container, the number of remaining selectable energy storage containers is n, n ≤ N;

[0100] S223: Group the n selectable energy storage containers according to the current SOC, with a grouping step of F and a grouping number of X, where X is rounded up to an integer, where X = (100-SOC LimitDown ) / F, the groups are sorted from high to low according to the SOC value range, and the group number value range is 1, 2, ..., X;

[0101] Specifically, SOC is the percentage of battery charge to battery capacity, with a maximum value of 100 and a minimum value of 0.

[0102] S224: Calculate the total maximum discharge power of each group of energy storage containers, and then accumulate the maximum discharge power of each group from the group with a high SOC value range to the group with a low SOC value range, until the accumulated maximum discharge power of each group is greater than or equal to the command power Pinst. At this time, the group participating in the accumulation is in the group selection range that meets the minimum power of the energy storage container under the command, and the maximum group number is set to X. min ; The number of groups not in the range is XX min ; The groups selected to participate in power allocation are 1~X min +(XX min ) / 2 rounded down;

[0103] If the accumulated maximum discharge power of the group is still less than the command power Pinst after all groups are accumulated, the optional energy storage container issues a command according to the maximum discharge power of the energy storage container.

[0104] S225: The number of currently selected energy storage containers is nSelected, and the average power of each energy storage container is The selected energy storage containers are sorted according to the current SOC (from large to small), and the power allocated to each energy storage container is an arithmetic progression.

[0105] If Pavg ≤ UnitDisChaLimitP / 2, the power allocated to the energy storage container with the lowest current SOC is 0. The number of elements in the arithmetic sequence is nSelected, the average value is Pavg, and the minimum value is 0. After calculating the values of each element in the arithmetic sequence, the energy storage containers are sorted by their current SOC. The higher the current SOC, the greater the power allocated. This power value is then allocated to each energy storage container.

[0106] Assume that the common difference of the arithmetic progression is gc; the power values allocated to each energy storage container are arranged in ascending order according to the current SOC:

[0107] 0, 0+1×gc, 0+2×gc,…, 0+(nSelected-1)gc.

[0108] In an arithmetic progression, (maximum value + minimum value) / 2 = average value; (0 + (nSelected-1)gc) / 2 = Pavg; (0 + (nSelected-1)gc) / 2 = Pinst / nSelected;

[0109] Power tolerance gc=(2×Pinst) / (nSelected 2 -nSelected);

[0110] After calculating the tolerance gc, substitute the result into the power value formula listed above for each energy storage container to obtain the discharge power allocated to each energy storage container.

[0111] If Pavg > UnitDisChaLimitP / 2, the maximum discharge power, UnitDisChaLimitP, is allocated to the energy storage container with the highest current SOC. The number of elements in the arithmetic sequence is nSelected, the average value is Pavg, and the maximum value is UnitDisChaLimitP. After calculating the values of the elements in the arithmetic sequence, the energy storage containers are sorted according to their current SOC. The higher the current SOC, the greater the power allocated. This power value is then allocated to each energy storage container.

[0112] The power values allocated to each energy storage container are arranged from largest to smallest according to the current SOC:

[0113] UnitDisChaLimitP, UnitDisChaLimitP-1×gc,…, UnitDisChaLimitP-(nSelected-1)×gc.

[0114] Since the arithmetic progression (maximum value + minimum value) / 2 = average value;

[0115] (UnitDisChaLimitP+UnitDisChaLimitP-(nSelected-1)×gc) / 2=Pavg;

[0116] (UnitDisChaLimitP+UnitDisChaLimitP-(nSelected-1)×gc) / 2=Pinst / nSelected;

[0117] The tolerance on power is calculated as follows:

[0118] gc=(2×(UnitDisChaLimitP×nSelected-Pinst)) / (nSelected 2 -nSelected);

[0119] After calculating the tolerance gc, the value of the tolerance gc is substituted into the power formula of each energy storage container to obtain the discharge power value allocated to each energy storage container.

[0120] If no new power command is received after waiting for Interval seconds, the current SOC of the energy storage container is re-collected, the above calculation is repeated, and power is reallocated to each container (when Interval is less than 0, the power recalculation logic is not executed).

[0121] The algorithm is further explained below through specific examples and in conjunction with the accompanying drawings.

[0122] Consistent with the conditions of the specific example of the charging power allocation algorithm, the attached Figure 3 The current SOC of each energy storage container in the energy storage station. During discharge, based on the lower limit of the discharge SOC, containers with a current SOC less than 10% are first excluded. Then, containers are grouped in steps of 10 based on their current SOC (since containers with a current SOC less than 10% are excluded, the current SOC range of the available energy storage containers is 10% to 100%), for a total of 9 groups. The current SOC ranges are arranged from high to low, as shown in Table 2.

[0123] Table 2 Grouping of energy storage containers

[0124]

[0125] Calculate the maximum discharge power for each group and then accumulate the group maximum discharge power, starting from the highest SOC value range to the lowest, until the accumulated group maximum discharge power is greater than or equal to the command power. According to the grouping in the table, groups 1-2 just meet the command requirements, and the maximum group number is 2. At this point, rounding down the formula 2 + (9-2) / 2 yields 5. This results in a selection range of groups 1-5, including 10 energy storage containers: EC_20, EC_19, EC_18, EC_17, EC_16, EC_15, EC_14, EC_13, EC_12, and EC_11. Arrange EC_20, EC_19, EC_18, EC_17, EC_16, EC_15, EC_13, EC_14, EC_12, and EC_11, in descending order of SOC. The average discharge power per container is 400W. Because the average power of 400W is ≤ the maximum discharge power of the energy storage container, 1000W / 2, the power value assigned to EC_11, which has the lowest SOC, is 0. The average value of the arithmetic progression is 400W, the minimum value is 0, and the number of elements is 10.

[0126] Use the formula gc=(2×Pinst) / (nSelected 2 -nSelected)=(2×4000) / (10 2 -10)=800 / 9;

[0127] According to the order of energy storage containers from high to low, the corresponding power calculation formula of each energy storage container (keep two decimal places).

[0128] EC_11: 0; EC_12: 0+1×gc=88.89; EC_14: 0+2×gc=177.89;

[0129] EC_13: 0+3×gc=266.89; EC_15: 0+4×gc=355.89; EC_16: 0+5×gc=444.89;

[0130] EC_17: 0+6×gc=533.89; EC_18: 0+7×gc=622.89; EC_19: 0+8×gc=711.89;

[0131] EC_20: 0+9×gc=800;

[0132] The energy storage containers are sorted according to the current SOC. The corresponding values of the power delivered by the energy storage containers are:

[0133] EC_11:0W; EC_12:88.89W; EC_13:266.89W; EC_14:177.89W;

[0134] EC_15:355.89W; EC_16:444.89W; EC_17:533.89W; EC_18:622.89W; EC_19:711.89W; EC_20:800W;

[0135] The timer starts after the power command is issued. If a new power command is received within 30 seconds, the charging or discharging power distribution calculation step is executed to distribute power to each container, and the timer is reset. If no new power command is received after 30 seconds, the current SOC of the energy storage container is obtained again, the above power distribution step is executed again, power is redistributed to each container, and the timer is reset.

[0136] The following describes the power allocation algorithm for differentiated energy storage containers:

[0137] When executing the differentiated energy storage container power allocation algorithm, there is no requirement for the consistency of the maximum charging and discharging power of each energy storage container, and dynamic changes in the maximum charging and discharging power of the energy storage container are supported.

[0138] Assume that the number of energy storage containers in the energy storage station is N, and the maximum charging and discharging power of the energy storage containers are inconsistent. The upper limit of the maximum SOC of charging is SOC LimitUp , the minimum discharge SOC lower limit is SOC LimitDown , the grouping step is F. The SOC value range is 0-100, the power Pinst is sent as the instruction, and the power calculation time interval is Interval seconds.

[0139] Table 3 below shows the maximum charging power and maximum discharging power values of each energy storage container.

[0140] Table 3 Maximum charging power and maximum discharging power of each energy storage container

[0141]

[0142] This allocation mode includes two parts of the instruction power allocation algorithm: charging power allocation and discharging power allocation. This algorithm can be flexibly configured according to the battery conditions of the energy storage station, the battery discharge lower limit SOC value, and the battery charging upper limit SOC value; and can adjust the step size of the SOC grouping according to the ratio of the total power of the energy storage station at full load to the size of the issued instruction power; and supports the energy storage container. The static differences (using echelon batteries, different battery procurement specifications) and dynamic differences (maintenance, battery attenuation) in the energy storage container cause inconsistent maximum charging and discharging power, and evenly distribute power. At the same time, according to the frequency of issuing power instructions, it can be configured whether to collect the current SOC, maximum charging power, and maximum discharging power of the energy storage container in real time, and redistribute the instruction power.

[0143] In S21, when executing the differential charging power allocation algorithm, the following steps are specifically included:

[0144] S21.1: When a charging command is received, obtain the current SOC and maximum charging power of all energy storage containers;

[0145] S21.2: Exclude the current SOC from being greater than SOC LimitUp (maximum SOC upper limit of charging) energy storage container, the number of remaining selectable energy storage containers is n, n ≤ N;

[0146] S21.3: Group the available energy storage containers according to the current SOC size, with a grouping step of F; the number of groups is X, X is rounded up, where X = SOC LimitUp / F; groups are sorted from low to high according to the SOC value range, and the group number value range is 1, 2, ..., X;

[0147] S21.4: Calculate the total maximum charging power of each group of energy storage containers, and then accumulate the maximum charging power of each group from the group with a low SOC value range to the group with a high SOC value range, until the accumulated maximum charging power of each group is greater than or equal to the command power Pinst. At this time, the group participating in the accumulation is in the selection range of the energy storage container with the minimum power under the command, and the maximum group number is set to X. min , the number of groups not in the range is XX min , then the groups selected to participate in power allocation are 1~X min +(XX min ) / 2 rounded down;

[0148] If the accumulated maximum charging power of all groups is still less than the command power Pinst after all groups are accumulated, the optional energy storage container issues a command according to the maximum charging power of each energy storage container;

[0149] S21.5: The number of currently selected energy storage containers is nSelected. The selected energy storage containers are sorted according to their current SOC sizes, and the allocated power value of each energy storage container is calculated.

[0150] Specifically, when calculating the allocated power value of each energy storage container in S21.5, the energy storage containers are sorted according to the current SOC and then plotted. The allocated power value of each energy storage container is calculated using the direct area method or the indirect common divisor area method. Assume that the container numbers of the selected energy storage containers are 1 to nSelected. For the convenience of expressing the algorithm steps here, there is no limit on the actual number of selected energy storage containers. The total maximum charging power of the selected energy storage containers is:

[0151] ChargeLimitTotalP=Unit1_ChargeLimitP+Unit2_ChargeLimitP+……+UnitnSelected_ChargeLimitP.

[0152] If Pinst ≥ ChargeLimitTotalP / 2, the charging power allocated to each container is calculated as follows:

[0153] First look at the attached Figure 4 , draw a rectangle with a width of 1 and a length equal to the total maximum charging power of the selected energy storage container ChargeLimitTotalP. The four vertices of the rectangle are A, B, C, and D. At this time, the area of the rectangle is equal to the available charging power (total maximum charging power) of the selected container. Connect points BC to get the following Figure 5 , the blue part in the figure is exactly half of the available charging power of the selected energy storage container. Because the command power is greater than half of the available charging power of the selected container, the BC connecting line is rotated clockwise with point B as the center until the area of the blue part is equal to the value of the command power. Figure 6 As shown in the attached Figure 6 The lower side is the horizontal axis, sort by SOC from large to small, mark the maximum charging power length interval of each energy storage container in the axis, and then extend the marked point upward to the upper side, such as Figure 7 As shown. Figure 7 The leftmost interval is the maximum power-length interval for charging the energy storage container with the current maximum SOC, and the rightmost interval is the maximum power-length interval for charging the energy storage container with the current minimum SOC.

[0154] It should be noted that the maximum charging power length intervals for each energy storage container should be marked in descending order according to their current SOC. For ease of illustration, the SOC values of the energy storage containers are assumed to decrease from 1 to nSelected. The area of the blue graph cut by the maximum charging power length intervals for each energy storage container represents the power allocated to each container. The power allocated to each container is calculated using mathematical formulas. Two calculation methods are described below: direct area calculation and indirect common divisor area calculation.

[0155] Direct area method:

[0156] calculate Figure 7 The area of each region in the , since the blue part is a right-angled trapezoid, according to the trapezoid area formula:

[0157] S trapezoid = (upper base + lower base) × height ÷ 2;

[0158] The blue part in the figure is a horizontal trapezoid, with the upper and lower bases becoming the left and right bases. At the same time, the area of the blue part is equal to Pinst, so (EC length + BD length) × ChargeLimitTotalP ÷ 2 = Pinst;

[0159] Because BD length is 1, EC length = 2 × Pinst ÷ ChargeLimitTotalP - 1;

[0160] Because it is a right trapezoid, the vertical line from EC to BD changes uniformly. Calculate the rate of change of the line perpendicular to the bottom side from EC to BD.

[0161] The rate of change Lrate is calculated as follows:

[0162] Lrate = (BD length - EC length) / ChargeLimitTotalP = (1 - (2 × Pinst ÷

[0163] ChargeLimitTotalP-1)) / ChargeLimitTotalP=

[0164] (2-2×Pinst÷ChargeLimitTotalP) / ChargeLimitTotalP;

[0165] The rate of change here is the change in the vertical line for each unit length moved to the right.

[0166] From this we can calculate the Figure 7 The maximum charging power length interval of each energy storage container is intercepted by the blue trapezoidal area.

[0167] The length of the left bottom of the blue trapezoid intercepted in the maximum charging power range of energy storage container 1 is:

[0168] 2×Pinst÷ChargeLimitTotalP-1;

[0169] The right bottom length is:

[0170] 2×Pinst÷ChargeLimitTotalP-1+Unit1_ChargeLimitP×Lrate;

[0171] The area of the blue trapezoidal portion of the maximum charging power interval of the energy storage container 1 in the figure can be calculated:

[0172] S Unit1 =(2×Pinst÷ChargeLimitTotalP-1+2×Pinst÷ChargeLimitTotalP

[0173] -1+Unit1_ChargeLimitP×Lrate)×Unit1_ChargeLimitP / 2;

[0174] The length of the left bottom of the blue part of the trapezoid for the maximum charging power interval of energy storage container 2 is equal to the length of the right bottom of the blue part of the trapezoid for the maximum charging power interval of energy storage container 1:

[0175] 2×Pinst÷ChargeLimitTotalP-1+Unit1_ChargeLimitP×Lrate;

[0176] The right bottom length is:

[0177] 2×Pinst÷ChargeLimitTotalP-1+(Unit1_ChargeLimitP+Unit2_ChargeLimitP)×Lrate;

[0178] The area of the blue trapezoidal section of the maximum charging power interval of the energy storage container 2 in the figure can be calculated as:

[0179] S Unit2 =(2×Pinst÷ChargeLimitTotalP-1+Unit1_ChargeLimitP×Lrate+2×

[0180] Pinst÷ChargeLimitTotalP-1+(Unit1_ChargeLimitP+Unit2_ChargeLimitP)×Lrate)×Unit2_ChagreLimitP / 2;

[0181] …

[0182] The length of the left bottom of the blue trapezoid of the energy storage container nSelected maximum charging power range is:

[0183] 2×Pinst÷ChargeLimitTotalP-1+(Unit1_ChargeLimitP+Unit2_ChargeLimitP+...+UnitnSelect-1_ChargeLimitP)×Lrate;

[0184] The right bottom length is:

[0185] 2×Pinst÷ChargeLimitTotalP-1+(Unit1_ChargeLimitP+Unit2_ChargeLimitP+……+UnitnSelect_ChargeLimitP)×Lrate;

[0186] The area of the blue trapezoidal section of the maximum charging power interval of the energy storage container nSelected in the figure can be calculated as:

[0187] S nSelected =(2×Pinst÷ChargeLimitTotalP-1+(Unit1_ChargeLimitP+

[0188] Unit2_ChargeLimitP+……+UnitnSelect-1_ChargeLimitP)×Lrate+2×Pinst÷ChargeLimitTotalP-1+(Unit1_ChargeLimitP+Unit2_ChargeLimitP+……+UnitnSelect_ChargeLimitP)×Lrate)×UnitnSelected_ChargeLimitP÷2.

[0189] Indirect common divisor method for calculating area:

[0190] First, calculate the greatest common divisor k of the maximum charging power of the selected energy storage container, and use the greatest common divisor as the interval unit to divide the attached Figure 7 The lower axis is split again as shown in the attached Figure 8 , the total number of intervals is q.

[0191] Because the width of the divided intervals is the same as the common divisor k, the area of the trapezoids divided by the common divisor interval is also an arithmetic progression. Take the two leftmost trapezoids as shown in the following Figure 9 , add some auxiliary lines.

[0192] It can be seen from the auxiliary lines in the figure:

[0193] The area of the blue part intercepted by the common divisor interval 1 = the area of the rectangle below + the area of the triangle above;

[0194] The area of the blue part of the common divisor interval 2 = the area of the lower rectangle + the area of the upper triangle + the area tolerance;

[0195] Area tolerance Stol = 2 × area of the upper triangle;

[0196] Attachment Figure 6 The middle blue part is a right-angled trapezoid. The area formula of the trapezoid is:

[0197] S trapezoid = (upper base + lower base) × height ÷ 2;

[0198] The blue part in the figure is a horizontal trapezoid, with the upper and lower bases becoming the left and right bases, and the area of the blue part is equal to Pinst;

[0199] It can be obtained that (EC length + BD length) × DisChaLimitTotalP ÷ 2 = Pinst;

[0200] Since the length of BD is 1, the length of EC = 2×Pinst / DisChaLimitTotalP-1;

[0201] The area of the lower rectangle is EC length × k = (2 × Pinst / DisChaLimitTotalP - 1) × k;

[0202] Therefore, the area of all common divisor intervals can be expressed as:

[0203] S1=(2×Pinst / DisChaLimitTotalP-1)×k+(1-1 / 2)×Stol;

[0204] S2=(2×Pinst / DisChaLimitTotalP-1)×k+(2-1 / 2)×Stol;

[0205] S3=(2×Pinst / DisChaLimitTotalP-1)×k+(3-1 / 2)×Stol;

[0206] …

[0207] Sq=(2×Pinst / DisChaLimitTotalP-1)×k+(q-1 / 2)×Stol;

[0208] S1+S2+S3+.....+Sq=Pinst;

[0209] Stol=(Pinst-q(2×Pinst / DisChaLimitTotalP-1)×k) / (1+2+3+...+qq / 2);

[0210] Substituting the area tolerance Stol into the above area expression can calculate the trapezoidal area intercepted by each common divisor interval. The power allocated to each container can be calculated by adding up the trapezoidal areas intercepted by the power common divisor intervals included in the container power interval.

[0211] If Pinst<ChargeLimitTotalP / 2, first see the attached Figure 4 , draw a rectangle with a width of 1 and a length equal to the total maximum charging power of the selected energy storage container ChargeLimitTotalP. The four vertices of the rectangle are A, B, C, and D. At this time, the area of the rectangle is equal to the available charging power (total maximum charging power) of the selected container. Connect points BC to get the following Figure 5 , the blue part in the figure is exactly half of the available charging power of the selected energy storage container. Because the command power is greater than half of the available charging power of the selected container, the BC connecting line is rotated clockwise with point C as the center until the area of the blue part is equal to the value of the command power. Figure 10 As shown in the attached Figure 10 The horizontal axis is in the middle and the current SOC is sorted from large to small. The maximum charging power length interval of each energy storage container is marked on the axis, such as Figure 11 shown.

[0212] The maximum charging power length intervals for each energy storage container are marked here. They should be marked in descending order according to the current SOC. For ease of illustration, we assume that the SOC values of the energy storage containers decrease from 1 to nSelected. The area of the blue shape cut by the straight lines marking the maximum charging power length intervals for each energy storage container represents the power allocated to each container. Use a mathematical formula to calculate the power allocated to each container. Two calculation methods are shown here: direct area calculation and indirect common divisor area calculation.

[0213] Direct area method:

[0214] Since the blue part is a right triangle, the formula for the area of a right triangle is: base × height ÷ 2;

[0215] Pinst = FD length × ChargeLimitTotalP ÷ 2 = 2 × Pinst ÷ ChargeLimitTotalP;

[0216] Because it is a right triangle, the vertical line from vertex C to FD changes uniformly, so the rate of change Lrate = (FD length - 0) / ChargeLimitTotalP = 2 × Pinst ÷ ChargeLimitTotalP 2 ;

[0217] The rate of change here is the change in the vertical line for each unit length moved to the right.

[0218] The blue figure intercepted by the maximum charging power length interval of energy storage container 1 is a special right-angled trapezoid with a left bottom length of 0 and a right bottom length of Unit1_ChargeLimitP×Lrate;

[0219] The area of the blue portion of the maximum charging power interval of the energy storage container 1 in the figure can be calculated as:

[0220] S Unit1 =(0+Unit1_ChargeLimitP×Lrate)×Unit1_ChargeLimitP / 2.

[0221] The length of the left bottom of the blue graph intercepted by the maximum charging power length interval of energy storage container 2 is equal to the length of the right bottom of the blue graph intercepted by the maximum charging power interval of energy storage container 1. The value is: Unit1_ChargeLimitP×Lrate;

[0222] The length of the right bottom is: (Unit1_ChargeLimptP+Unit2_ChargeLimitP)×Lrate;

[0223] The area of the blue portion of the maximum charging power length interval of energy storage container 2 is: S Unit2 =(Unit1_ChargeLimitP×Lrate+(Unit1_ChargeLimitP+Unit2_ChargeLimitP)×Lrate)×Unit2_ChargeLimitP÷2;

[0224] …

[0225] The length of the left bottom of the blue portion of the maximum charging power length interval of the energy storage container nSelected is:

[0226] (Unit1_ChargeLimitP+Unit2_ChargeLimitP+Unit3_ChargeLimitP+……+UnitnSelected-1_ChargeLimitP)×Lrate;

[0227] The right bottom length is:

[0228] (Unit1_ChargeLimitP+Unit2_ChargeLimitP+Unit3_ChargeLimitP+……+UnitnSelected_ChargeLimitP)×Lrate;

[0229] The area of the blue portion of the maximum charging power length interval of the energy storage container nSelected is:

[0230] S UnitnSelected =

[0231] ((Unit1_ChargeLimitP+Unit2_ChargeLimitP+Unit3_ChargeLimitP+……+

[0232] UnitnSelected-1_ChargeLimitP)×Lrate+(Unit1_ChargeLimitP+

[0233] Unit2_ChargeLimitP+……+Unit3_ChargeLimitP+……+

[0234] UnitnSelected_ChargeLimitP)×Lrate)×UnitnSelected_ChargeLimitP÷2;

[0235] The blue area of the maximum charging power interval of each energy storage container is the power allocated to each energy storage container.

[0236] Indirect common divisor method for calculating area:

[0237] First, calculate the greatest common divisor k of the maximum charging power of the selected energy storage container. Use the greatest common divisor as the interval unit to Figure 11 The lower axis is split again as shown in the attached Figure 12 , the total number of intervals is q.

[0238] Because the width of the segmented intervals is the same as the common divisor k, the area of the segmented trapezoids is also an arithmetic progression. Take the two leftmost trapezoids as shown in the following Figure 13 , add some auxiliary lines.

[0239] It can be seen from the auxiliary lines in the figure:

[0240] The area of the blue part intercepted by the common divisor interval 1 = the area of the triangle above;

[0241] The area of the blue part intercepted by the common divisor interval 2 = the area of the upper triangle + the area tolerance;

[0242] Area tolerance Stol = 2 × area of the upper triangle:

[0243] The area of the blue part intercepted by all common divisor intervals can be expressed as:

[0244] S1=(1 / 2)×Stol; S2=(1 / 2)×Stol+1×Stol; S3=(1 / 2)×Stol+2×Stol;

[0245] …

[0246] Sq=(1 / 2)×Stol+(q-1)×Stol;

[0247] S1+S2+S3+.....+Sq=Pinst

[0248] Stol=Pinst / (1+2+3+...+qq / 2);

[0249] Substituting the area tolerance Stol into the above area expression can calculate the area of the blue part intercepted by each tolerance interval. The power allocated to each container can be calculated by summing the trapezoidal areas intercepted by the power tolerance intervals included in the container power interval.

[0250] If no new power command is received after waiting for Interval seconds, the current SOC of the energy storage container is re-collected, the above calculation is repeated, and power is reallocated to each container (when Interval is less than 0, the power recalculation logic is not executed).

[0251] The algorithm is further explained below through specific examples and in conjunction with the accompanying drawings.

[0252] For example, the current energy storage station contains 10 energy storage containers. The maximum charging power and current SOC value of each energy storage container are shown in Table 4.

[0253] Table 4 Maximum charging power and current SOC value of each energy storage container

[0254]

[0255] The upper limit of the energy storage container charging SOC is 90%, the lower limit of the discharge SOC is 10%, the SOC grouping step is 20, the charging power command is 2000w, and the power calculation time interval is set to 30s.

[0256] During charging, based on the upper limit of the charging SOC, energy storage containers with a current SOC greater than 90% are first excluded. Then, the containers are grouped in steps of 20 based on their current SOC. (Since containers with a current SOC greater than 90% are excluded, the selectable SOC range for energy storage containers is 0% to 90%, resulting in a total of five groups. The group SOC ranges are arranged from low to high, as shown in Table 5.)

[0257] Table 5 Group SOC ranking of energy storage containers

[0258] Group Group 1 Group 2 Group 3 Group 4 Group 5 Current SOC range 0-20 20-40 40-60 60-80 80-90 Energy storage container EC_1, EC_2 EC_3, EC_4 EC_5, EC_6 EC_7, EC_8 EC_9

[0259] After grouping, calculate the sum of the maximum charging power of each group, and add the group maximum charging power in sequence from the group with the lower SOC value range to the group with the higher SOC value range, until the accumulated group maximum charging power is greater than or equal to the command power. According to the grouping in Table 5, the maximum charging power of the energy storage container group included in Groups 1-2 meets the command requirements. The maximum group number is 2. At this time, according to the formula, 2+(5-2) / 2 is rounded down to 3. It can be concluded that the selected group range is 1-3, including EC_1, EC_2, EC_3, EC_4, EC_5, and EC_6, a total of 6 energy storage containers. The calculated sum of the maximum charging power of the selected energy storage containers is 4500w.

[0260] Because the command power is 2000w < half of the maximum total charging power of 4500w for the selected container.

[0261] According to the attached Figure 10 Draw the power distribution diagram as shown in the attached Figure 14 shown.

[0262] The area of the blue part in the figure is 2000 and the CD length is 4500.

[0263] In the attached Figure 14 The coordinate axis is from left to right. According to the current SOC value, mark the maximum charging power length interval of the energy storage container from large to small, and then extend the mark point upward to the top as shown in the attached figure. Figure 15 shown.

[0264] Attachment Figure 15 The blue area intercepted by the maximum charging power length interval of each energy storage container is the power value allocated to each energy storage container.

[0265] Calculate the values using the direct area method and use the formula in the algorithm to find the FD length:

[0266] FD length = 2 × Pinst ÷ ChargeLimit TotalP = 2 × 2000 ÷ 4500 = 8 / 9.

[0267] Calculate the change rate Lrate = (8 / 9) ÷ 4500 = 8 / (9×4500).

[0268] Calculate the area of the blue portion of the EC_6 maximum charging power length interval:

[0269] The blue part of the EC_6 charging maximum power length interval is cut into a right triangle, which can be regarded as a special right trapezoid with a left base of 0.

[0270] The left bottom of the blue part of the EC_6 charging maximum power length interval is: 0;

[0271] The right bottom of the blue part of the EC_6 maximum charging power length interval is:

[0272] 0+1000×Lrate=0+1000×(8 / (9×4500))=16 / 81;

[0273] The area of the blue portion of the EC_6 maximum charging power length interval is:

[0274] (0+16 / 81)×1000÷2=98.76 (keep two decimal places).

[0275] Calculate the area of the blue portion of the EC_5 maximum charging power length interval:

[0276] The left bottom of the blue portion of the EC_5 maximum charging power length interval and the right bottom of the blue portion of the EC_6 maximum charging power length interval are the same:

[0277] 0+1000×Lrate=0+(8 / (9×4500))×1000=16 / 81;

[0278] The right bottom of the blue part of the EC_5 maximum charging power length interval is:

[0279] 0+(1000+500)×Lrate=0+(1000+500)×(8 / (9×4500))=8 / 27;

[0280] The area of the blue part of the EC_5 charging maximum power length interval is:

[0281] (16 / 81+8 / 27)×500÷2=123.45 (keep two decimal places).

[0282] Calculate the area of the blue portion of the EC_4 maximum charging power length interval:

[0283] The left bottom of the blue portion of the EC_4 maximum charging power length interval is the same as the right bottom of the blue portion of the EC_5 maximum charging power length interval:

[0284] 0+(1000+500)×Lrate=0+(8 / (9×4500))×1500=8 / 27;

[0285] The right bottom of the blue part of the EC_4 maximum charging power length interval is:

[0286] 0+(1000+500+1000)×Lrate=0+(1000+500+1000)×(8 / (9×4500))=40 / 81;

[0287] The area of the blue part of the EC_4 maximum charging power length interval is:

[0288] (8 / 27+40 / 81)×1000÷2=395.06 (keep two decimal places).

[0289] Calculate the area of the blue portion of the EC_3 maximum charging power length interval:

[0290] The left bottom of the blue portion of the EC_3 maximum charging power length interval is the same as the right bottom of the blue portion of the EC_4 maximum charging power length interval, which is:

[0291] 0+(1000+500+1000)×Lrate=0+(1000+500+1000)×(8 / (9×4500))=40 / 81;

[0292] The right bottom of the blue portion of the EC_3 maximum charging power length interval is: 0+(1000+500+1000+500)×Lrate=0+(1000+500+1000+500)×(8 / (9×4500))=16 / 27;

[0293] The blue part of the EC_3 maximum charging power length interval is as follows:

[0294] (40 / 81+16 / 27)×500÷2=271.6 (keep two decimal places).

[0295] Calculate the area of the blue portion of the EC_2 maximum charging power length interval:

[0296] The left bottom of the blue portion of the EC_2 maximum charging power length interval is the same as the right bottom of the blue portion of the EC_3 maximum charging power length interval, which is: 0 + (1000 + 500 + 1000 + 500) × Lrate = 0 + (1000 + 500 + 1000 + 500) × (8 / (9 × 4500)) = 16 / 27;

[0297] The right bottom of the blue part of the EC_2 maximum charging power length interval is:

[0298] 0+(1000+500+1000+500+1000)×Lrate=0+(1000+500+1000+500+1000)×(8 / (9×4500))=64 / 81;

[0299] The area of the blue part of the EC_2 maximum charging power length interval is:

[0300] (16 / 27+64 / 81)×1000÷2=691.35 (keep two decimal places).

[0301] Calculate the area of the blue portion of the EC_1 maximum charging power length interval:

[0302] The left bottom of the blue portion of the EC_1 maximum charging power length interval is the same as the right bottom of the blue portion of the EC_2 maximum charging power length interval, which is:

[0303] 0+(1000+500+1000+500+1000)×Lrate=0+(1000+500+1000+500+1000)×(8 / (9×4500))=64 / 81;

[0304] The right bottom of the blue part of the EC_1 charging maximum power length interval is:

[0305] 0+(1000+500+1000+500+1000)×Lrate=0+(1000+500+1000+500+1000+500)×(8 / (9×4500))=8 / 9;

[0306] The area of the blue part of the EC_1 maximum charging power length interval is:

[0307] (64 / 81+8 / 9)×500÷2=419.75 (keep two decimal places).

[0308] Therefore, the charging power allocated to each energy storage container is:

[0309] EC_1:419.75w; EC_2:691.35w; EC_3:271.6w; EC_4:395.06w; EC_5:123.45w; EC_6:98.76w.

[0310] Calculate the values using the indirect common divisor method:

[0311] The maximum charging power of each energy storage container is 500w, 1000w, 500w, 1000w, 500w, and 1000w respectively, and the greatest common divisor of the maximum charging power is 500.

[0312] Use 500 as the interval unit and divide the attached Figure 15 , get attached Figure 16 .

[0313] The area of the upper triangle is half the tolerance area. Let the tolerance area be Stol.

[0314] The area of interval 1 = (1 / 2) × Stol; the area of interval 2 = (1 / 2) × Stol + 1 × Stol;

[0315] The area of interval 3 = (1 / 2) × Stol + 2 × Stol; the area of interval 4 = (1 / 2) × Stol + 3 × Stol;

[0316] …

[0317] The area of interval 9 = (1 / 2) × Stol + 8 × Stol.

[0318] Total area of blue part:

[0319] 2000=(1 / 2)×Stol+(1 / 2)×Stol+1×Stol+1 / 2)×Stol+2×Stol+(1 / 2)×Stol+3×Stol+(1 / 2)×Stol+4×Stol+(1 / 2)×Stol+

[0320] 5×Stol+(1 / 2)×Stol+6×Stol+(1 / 2)×Stol+7×Stol+(1 / 2)×Stol+8×Stol=9×(1 / 2)×Stol+(1+2+3+4+5+6+7+8)Stol=

[0321] 40.5×Stol;

[0322] Among them, Stol = 49.38 (keep two decimal places)

[0323] The area of the blue part intercepted in interval 1 is 24.69; the area of the blue part intercepted in interval 2 is 74.07;

[0324] The area of the blue part of interval 3 is 123.45; the area of the blue part of interval 4 is 172.83;

[0325] The area of the blue part of interval 5 is 222.21; the area of the blue part of interval 6 is 271.59;

[0326] The area of the blue part intercepted by interval 7 is 320.97; the area of the blue part intercepted by interval 8 is 370.35;

[0327] The area of the blue part intercepted by interval 9 is 419.73.

[0328] like Figure 16 As shown, the EC_1 charging maximum power length interval only contains the common divisor interval 9, so the area of the blue part of the EC_1 charging maximum power length interval is 419.73.

[0329] The EC_2 maximum charging power length interval includes the common divisor interval 7 and the common divisor interval 8, so the area of the blue part of the EC_2 maximum charging power length interval is 320.97+370.35=691.32.

[0330] Similarly, the area of the blue part of the EC_3 maximum charging power length interval is 271.59, and the area of the blue part of interval 6 is 271.59.

[0331] The area of the blue part of the EC_4 maximum charging power length interval is 172.83+222.21=395.04.

[0332] The EC_5 charging maximum power length interval contains the common divisor interval 3, so the area of the blue part of the EC_5 charging maximum power length interval is 123.45.

[0333] The EC_6 maximum charging power length interval includes common divisor interval 1 and common divisor interval 2, so the area of the blue part of the EC_6 maximum charging power length interval is 24.69+74.07=98.76.

[0334] Therefore, the power allocated to the 6 energy storage containers is:

[0335] EC_1:419.73w; EC_2:691.32w; EC_3:271.59w; EC_4:395.04w; EC_5:123.45w; EC_6:98.76w;

[0336] The results calculated by the two methods are roughly the same (because only two decimal places are retained during the calculation process, some precision is lost, so the results of the two calculations will not be exactly the same).

[0337] In S22, when the differential discharge power allocation algorithm is executed, the following steps are specifically included:

[0338] S22.1: When a discharge instruction is received, the current SOC and maximum discharge power of all energy storage containers are obtained.

[0339] S22.2: Exclude the energy storage container whose current SOC is less than SOC LimitDown (discharge minimum SOC lower limit) energy storage container, the number of remaining optional energy storage containers is n (n≤N).

[0340] S22.3: Group the available energy storage containers according to the current SOC. The grouping step is F and the number of groups is X = ((100-SOC LimitDown ) / F) rounded up. Groups are sorted from high to low based on the SOC value range, and the group number range is 1, 2, ..., X.

[0341] S22.4: Calculate the total maximum discharge power of each group of energy storage containers, and then accumulate the maximum discharge power of each group from the group with a higher SOC value range to the group with a lower SOC value range, until the accumulated maximum discharge power of each group is greater than or equal to the command power Pinst. At this time, the group participating in the accumulation is in the group selection range that meets the minimum command power of the energy storage container, and the maximum group number is X min , the number of groups not in the range is XX min , then the groups selected to participate in power allocation are 1~X min +(XX min ) / 2 rounded down;

[0342] If the accumulated maximum discharge power of all groups is still less than the commanded power Pinst after all groups are accumulated, the optional energy storage container issues a power command according to the maximum discharge power of each energy storage container.

[0343] S22.5: The number of currently selected energy storage containers is nSelected. The selected energy storage containers are sorted according to their current SOC sizes, and the power value allocated to each energy storage container is calculated.

[0344] Specifically, when calculating the power value allocated to each energy storage container in S22.5, the energy storage containers are sorted according to the current SOC and then plotted, and the power value allocated to each energy storage container is calculated using a direct area method or an indirect common divisor area method.

[0345] Here, it is assumed that the container numbers of the selected energy storage containers are 1 to nSelected. In order to facilitate the expression of the algorithm steps, there is no limit on the actual number of selected containers. The total maximum discharge power of the selected energy storage containers is: DisChaLimitTotalP = Unit1_DisChaLimitP + Unit2_DisChaLimitP + ... + UnitnSelected_DisChaLimitP;

[0346] First look at the attached Figure 17 , draw a rectangle with a width of 1 and a length equal to the total maximum discharge power DisChaLimitTotalP of the selected energy storage container. The four vertices of the rectangle are A, B, C, and D. At this time, the area of the rectangle is 1×DisChaLimitTotalP=DisChaLimitTotalP. The area of the rectangle is equal to the total available discharge power (maximum discharge power) of the selected energy storage container. Figure 17 Point BC in the diagram, get the attached Figure 18 Attached Figure 18 The area of the middle blue part is half of the rectangle, which is equal to half of the maximum discharge power of the selected energy storage container.

[0347] When Pinst≥DisChaLimitTotalP / 2, the BC line rotates clockwise with point B as the center until the area of the blue part is equal to the command power. Figure 19 shown.

[0348] In the attached Figure 19 The lower side is the horizontal axis, sorted from small to large according to the current SOC, and the maximum discharge power length interval of the selected energy storage container is marked on the axis, and then the marked point is extended upward to the upper side, such as Figure 20 shown.

[0349] It should be noted that the maximum discharge intervals for each energy storage container must be marked in ascending order of SOC. For ease of illustration, the current SOC of the energy storage station containers is assumed to increase in sequence from 1 to nSelected. The area of the blue graph cut by the straight lines marking each energy storage container's intervals represents the power allocated to each container. The allocated power value for each container is calculated using mathematical formulas. Two calculation methods are illustrated here: the direct area method and the indirect common divisor area method.

[0350] Direct area method:

[0351] Figure 20 The middle blue part is a right-angled trapezoid. The area formula of the trapezoid is:

[0352] S trapezoid = (upper base + lower base) × height ÷ 2;

[0353] The blue part in the figure is a horizontal trapezoid, with the upper and lower bases becoming the left and right bases. At the same time, the area of the blue part is equal to Pinst, so (EC length + BD length) × DisChaLimitTotalP ÷ 2 = Pinst;

[0354] Since the length of BD is 1, the length of EC = 2 × Pinst / DisChaLimitTotalP - 1;

[0355] Because it is a right-angled trapezoid, the vertical line from EC to BD changes uniformly. Calculate the change rate Lrate: Lrate = (BD length - EC length) / DisChaLimitTotalP = (1 - (2 × Pinst / DisChaLimitTotalP - 1)) / DisChaLimitTotalP =

[0356] (2-2×Pinst / DisChaLimitTotalP) / DisChaLimitTotalP;

[0357] Here, the rate of change is the change in the vertical line for each unit length moved to the right. From this, we can calculate the maximum discharge power length interval of energy storage container 1 by intercepting the blue trapezoid, that is:

[0358] The length of the left bottom is 2×Pinst / DisChaLimitTotalP-1;

[0359] The length of the bottom on the right is 2×Pinst / DisChaLimitTotalP-1+Unit1_DisCharLimitP×Lrate. According to the trapezoid area calculation formula, calculate the area of the blue trapezoid intercepted by the maximum discharge power length interval of energy storage container 1 in the figure:

[0360] S Unit1 =(2×Pinst / DisChaLimitTotalP-1+2×Pinst / DisChaLimitTotalP-

[0361] 1+Unit1_DisCharLimitP×Lrate)×Unit1_DisCharLimitP÷2;

[0362] The maximum discharge power length interval of energy storage container 2 is intercepted by the blue trapezoid:

[0363] The length of the left bottom is the same as the length of the right bottom of the blue trapezoid intercepted by the maximum discharge power length interval of energy storage container 1, which is: 2×Pinst / DisChaLimitTotalP-1+Unit1_DisCharLimitP×Lrate;

[0364] The length of the right bottom is: 2×Pinst / DisChaLimitTotalP-1+(Unit1_DisChaLimitP+Unit2_DisChaLimitP)×Lrate;

[0365] The area of the blue trapezoid intercepted in the maximum power length interval of energy storage container 2 in the calculation diagram is:

[0366] S Unit2 =(2×Pinst / DisChaLimitTotalP-1+Unit1_DisChaLimitP×Lrate+

[0367] 2×Pinst / DisChaLimitTotalP-1+(Unit1_DisChaLimitP+Unit2_DisChaLimitP)×Lrate)×Unit2_DisCharLimitP÷2;

[0368] …

[0369] The length of the left bottom of the blue trapezoid intercepted by the maximum power length interval of the energy storage container nSelected discharge is:

[0370] 2×Pinst / DisChaLimitTotalP-1+(Unit1_DisChaLimitP+

[0371] Unit2_DisCharLimit+……+UnitnSelected-1_DisChaLimitP)×Lrate;

[0372] The right bottom length is:

[0373] 2×Pinst / DisChaLimitTotalP-1+(Unit1_DisChaLimitP+

[0374] Unit2_DisCharLimit+……+UnitnSelected_DisChaLimitP)×Lrate=(2×Pinst / DisChaLimitTotalP-1)+DisChaLimitTotalP×Lrate=1;

[0375] The area of the blue trapezoid intercepted by the maximum discharge power length interval of the energy storage container nSelected is:

[0376] S UnitnSelected =

[0377] (2×Pinst / DisChaLimitTotalP-1+(Unit1_DisChaLimitP+

[0378] Unit2_DisCharLimit+……+UnitnSelected-1_DisChaLimitP)×Lrate+2×Pinst / DisChaLimitTotalP-1+(Unit1_DisChaLimitP+Unit2_DisChaLimit+……+UnitnSelected_DisChaLimitP)×Lrate)×UnitnSelected_DisChaLimit÷2.

[0379] The indirect common divisor method for calculating area is introduced as follows:

[0380] First, calculate the greatest common divisor k of the maximum discharge power of the energy storage container, use the greatest common divisor as the interval unit, and Figure 17 Split again on the lower axis, such as Figure 21 As shown, the total number of intervals is q.

[0381] Because the width of the segmented intervals is the same as the common divisor k, the area of the segmented trapezoids is also an arithmetic progression. Take the two leftmost trapezoids as Figure 9 As shown, add some auxiliary lines.

[0382] It can be seen from the auxiliary lines in the figure:

[0383] The area of the blue part intercepted by the common divisor interval 1 = the area of the rectangle below + the area of the triangle above;

[0384] The area of the blue part of the common divisor interval 2 = the area of the lower rectangle + the area of the upper triangle + the area tolerance;

[0385] Area tolerance Stol = 2 × area of the upper triangle;

[0386] The blue part in the figure is a right-angled trapezoid. The area formula of the trapezoid is:

[0387] S 梯形 =(upper base + lower base) × height ÷ 2;

[0388] The blue part in the figure is a horizontal trapezoid, with the upper and lower bases becoming the left and right bases, and the area of the blue part is equal to Pinst;

[0389] It can be obtained that: (EC length + BD length) × DisChaLimitTotalP ÷ 2 = Pinst;

[0390] Since the length of BD is 1, the length of EC = 2 × Pinst / DisChaLimitTotalP - 1;

[0391] The area of the rectangle below is: EC length × k = (2 × Pinst / DisChaLimitTotalP - 1) × k. Therefore, the area of all common divisor intervals can be expressed as:

[0392] S1=(2×Pinst / DisChaLimitTotalP-1)×k+(1-1÷2)×Stol;

[0393] S2=(2×Pinst / DisChaLimitTotalP-1)×k+(2-1÷2)×Stol;

[0394] …

[0395] Sq=(2×Pinst / DisChaLimitTotalP-1)×k+(q-1÷2)×Stol;

[0396] S1+S2+S3+......+Sq=Pinst;

[0397] Stol=(q(2×Pinst / DisChaLimitTotalP-1)×k) / (1+2+3+......+qq / 2).

[0398] Substituting the area tolerance Stol into the above common divisor area expression can calculate the trapezoidal area intercepted by each tolerance interval. The distributed power of each container can be calculated by summing the trapezoidal areas intercepted by the power common divisor intervals included in the container power interval.

[0399] If Pinst<ChargeLimitTotalP / 2, Figure 18 On the basis of , rotate the BC connecting line clockwise with point C as the center until the area of the blue part is equal to the power issued by the instruction, such as Figure 22 shown.

[0400] exist Figure 22 The lower side is the horizontal axis, sorted from small to large according to the current SOC, and the maximum discharge power length interval of the selected energy storage container is marked on the axis, and then the marked point is extended upward to the upper side, such as Figure 23 shown.

[0401] Here, the maximum power length interval of each energy storage unit discharge is marked. It needs to be marked in order from low to high according to the current SOC. For the convenience of representation, it is assumed that the current SOC of the energy storage container increases from 1 to nSelected in sequence.

[0402] At this time, the blue graphic area cut by the maximum discharge power length interval marked on the figure for each energy storage container is the power size allocated to each energy storage container.

[0403] Use mathematical formulas to calculate the power allocated to each energy storage container. Two calculation methods are provided here: direct area calculation method and indirect common divisor area calculation method.

[0404] Direct area method:

[0405] Since the blue part is a right triangle, the formula for the area of a right triangle is: base × height ÷ 2;

[0406] FD length × DisChaLimitTotalP ÷ 2 = Pinst;

[0407] FD length = 2 × Pinst / DisChaLimitTotalP;

[0408] Because it is a right triangle, the length of the vertical line from vertex C to FD changes uniformly, and the rate of change Lrate is calculated as follows:

[0409] Lrate = (FD length - 0) / DisChaLimitTotalP = 2 × Pinst / (DisChaLimitTotalP × DisChaLimitTotalP);

[0410] The rate of change here is the change in the vertical line for each unit length moved to the right.

[0411] The blue figure intercepted by the maximum discharge power length interval of energy storage container 1 can be regarded as a special right-angled trapezoid with a left base length of 0.

[0412] The length of the bottom on the right is Unit1_DisChaLimitP×Lrate. The area of the blue portion intercepted by the maximum discharge power length interval of energy storage container 1 can be calculated as:

[0413] S Unit1 =(0+Lrate×Unit1_DisChaLimitP)×Unit1_DisChaLimitP÷2.

[0414] The length of the left bottom of the blue portion of the maximum discharge power length interval of energy storage container 2 is equal to the length of the right bottom of the blue portion of the maximum discharge power length interval of energy storage container 1, which is Unit1_DisChaLimitP×Lrate.

[0415] The length of the right bottom of the blue part of the maximum discharge power length interval of energy storage container 2 is:

[0416] (Unit1_DisChaLimitP+Unit2_DisChaLimitP)×Lrate;

[0417] The area of the blue portion of the maximum power length interval of the energy storage container 2 in the figure is: S Unit2 (Unit1_DisChaLimitP×Lrate+(Unit1_DisChaLimitP+

[0418] Unit2_DisChaLimitP)×Lrate)×Unit2_DisChaLimitP÷2;

[0419] …

[0420] The length of the left bottom of the blue part of the maximum discharge power length interval of the energy storage container nSelected is:

[0421] (Unit1_DisChaLimitP+Unit2_DisChaLimitP+......+UnitnSelected-1_DisChaLimitP)×Lrate;

[0422] The right bottom length of the blue portion of the maximum discharge power length interval of the energy storage container nSelected is:

[0423] (Unit1_DisChaLimitP+Unit2_DisChaLimitP+……+

[0424] UnitSelected_DisChaLimitP)×Lrate;

[0425] The area of the blue part of the maximum power length interval of the energy storage container nSelected is: S UinitnSelected =

[0426] ((Unit1_DisChaLimitP+Unit2_DisChaLimitP+……+UnitnSelected-1_DisChaLimitP)×Lrate)+(Unit1_DisChaLimitP+

[0427] Unit2_DisChaLimitP+......+UnitnSelected_DischaLimitP)×Lrate)×

[0428] UnitnSelected_DisChaLimitP÷2;

[0429] The blue area of the maximum discharge power interval of each energy storage container is the discharge power allocated to each energy storage container.

[0430] Indirect common divisor method for calculating area:

[0431] First, calculate the greatest common divisor k of the maximum discharge power of the selected energy storage container. Use the greatest common divisor as the interval unit. Figure 23 Split again on the lower axis as Figure 24 , the total number of tolerance intervals is q. Because the width of the divided intervals is a common divisor k, the area of the trapezoids divided by each interval is also an arithmetic progression (the right triangle is regarded as a special right trapezoid with a base of 0). Take the trapezoids at the two ends on the right side as follows Figure 13 As shown in the figure, some auxiliary lines are added. It can be seen from the auxiliary lines in the figure:

[0432] The area of the blue part intercepted by the common divisor interval 1 = the area of the upper triangle;

[0433] The area of the blue part intercepted by the common divisor interval 2 = the area of the upper triangle + the area tolerance;

[0434] Area tolerance Stol = 2 × area of the upper triangle;

[0435] Therefore, the area of all tolerance intervals can be expressed as:

[0436] S1=(1 / 2)×Stol; S2=(1 / 2)×Stol+1×Stol; S3=(1 / 2)×Stol+2×Stol;

[0437] …

[0438] Sq=(1 / 2)×Stol+(q-1)×Stol;

[0439] S1+S2+S3+……+Sq=Pinst;

[0440] Stol=Pinst / (1+2+3+……+qq / 2);

[0441] Substituting the area tolerance Stol into the above area expression can calculate the trapezoidal area intercepted by each common divisor interval. The discharge power allocated to each container can be calculated by summing the trapezoidal areas intercepted by the power common divisor intervals included in the container discharge power interval.

[0442] If no new power command is received after waiting for Interval seconds, the current SOC, maximum charging power, and maximum discharging power of the energy storage container are re-collected, and the above calculation is repeated to re-allocate power to each container (when Interval is less than 0, the power recalculation logic is not executed).

[0443] The algorithm is further explained below through specific examples and in conjunction with the accompanying drawings.

[0444] For example, the current energy storage station contains 10 energy storage containers. The maximum discharge power and current SOC of each energy storage container are shown in Table 6.

[0445] Table 6 Maximum discharge power and current SOC of each energy storage container

[0446]

[0447] The upper limit of the energy storage container charging SOC is 90%, the lower limit of the discharge SOC is 10%, the SOC grouping step is 20, the instruction-issued discharge power is 3000w, and the power calculation time interval is set to 30s.

[0448] During discharge, according to the lower limit of the discharge SOC, energy storage containers with a current SOC less than 10% are first excluded. Then, the energy storage containers are grouped in steps of 20 according to their current SOC (since the current SOC less than 10% is excluded, the current SOC range of the optional energy storage containers is 10% to 100%). A total of 5 groups are divided, and the group SOC value ranges are sorted from high to low, as shown in Table 7.

[0449] Table 7 SOC value ranges are sorted from high to low

[0450] Group Group 1 Group 2 Group 3 Group 4 Group 5 Current SOC range 100-80 80-60 60-40 40-20 20-10 Energy storage container EC_10, EC_9 EC_8, EC_7 EC_6, EC_5 EC_4, EC_3 EC_2

[0451] After grouping, calculate the maximum discharge power for each group. The group maximum discharge powers are then accumulated, starting from the group with the highest SOC value range and moving downwards, until the total accumulated group maximum discharge power exceeds the command power. Based on the grouping in the table, the maximum discharge power of the energy storage containers in groups 1-2 meets the command requirements. The maximum group number is 2. According to the formula, 2 + (5 - 2) / 2 is rounded down to 3. This indicates that the selected groups range from 1 to 3, including six energy storage containers: EC_10, EC_9, EC_8, EC_7, EC_6, and EC_5. The total maximum discharge power of the selected energy storage containers is calculated to be 4500W.

[0452] Because the command power is 3000W ≥ half of the total maximum discharge power of the selected container, 4500W.

[0453] according to Figure 20 Draw a power distribution diagram, such as Figure 25 As shown in the figure, the area of the blue part is 3000 and the CD length is 4500. Figure 25 In the middle, the coordinate axis is the bottom edge. From left to right, mark the maximum power length interval of the energy storage container discharge from small to large according to the current SOC size, and then extend the marked points upward to the top edge, such as Figure 26 As shown. Figure 26 In the figure, the blue area intercepted by the maximum power length interval of each energy storage container is the power value allocated to each energy storage container.

[0454] Calculate the values using the direct area method and use the formula in the algorithm to find the EC length:

[0455] EC length = 2 × Pinst / DisChaLimitTotalP - 1 = 2 × 3000 / 4500 - 1 = 1 / 3;

[0456] Calculate the rate of change Lrate = (1-1 / 3)4500 = 2 / (3×4500);

[0457] Calculate the area of the blue portion of the EC_5 maximum discharge power length interval:

[0458] The length of the left base of EC_5 is 1 / 3;

[0459] The length of the right base of EC_5 is 1 / 3 + 500 × Lrate = 1 / 3 + 500 × 2 / (3 × 4500) = 11 / 27;

[0460] The blue area intercepted by the EC_5 discharge maximum power length interval is:

[0461] (1 / 3+11 / 27)×500÷2=185.18 (keep two decimal places).

[0462] Calculate the area of the blue portion of the EC_6 maximum discharge power length interval:

[0463] The left base of the blue portion of the EC_6 maximum power length interval is the same as the right base of the blue portion of the EC_5 maximum power length interval, which is: 1 / 3 + 500 × Lrate = 1 / 3 + 500 × 2 / (3 × 4500) = 11 / 27;

[0464] The right bottom of the blue part of the EC_6 maximum discharge power length interval is: 1 / 3+(500+1000)×Lrate=1 / 3+1500×2 / (3×4500)=5 / 9;

[0465] The area of the blue part of the EC_6 maximum discharge power length interval is:

[0466] (11 / 27+5 / 9)×1000÷2=481.48 (keep two decimal places).

[0467] Calculate the area of the blue portion of the EC_7 maximum discharge power length interval:

[0468] The left base of the blue portion of the EC_7 maximum power length interval is the same as the right base of the blue portion of the EC_6 maximum power length interval, which is: 1 / 3 + (500 + 1000) × Lrate = 1 / 3 + 1500 × 2 / (3 × 4500) = 5 / 9;

[0469] The right bottom of the blue part of the EC_7 maximum discharge power length interval is:

[0470] 1 / 3+(500+1000+500)×Lrate=1 / 3+2000×2 / (3×4500)=17 / 27;

[0471] The area of the blue part of the EC_7 maximum discharge power length interval is:

[0472] (5 / 9+17 / 27)×500÷2=296.29 (keep two decimal places).

[0473] Calculate the area of the blue portion of the EC_8 maximum discharge power length interval:

[0474] The left bottom of the blue portion of the EC_8 maximum discharge power length interval is the same as the right bottom of the blue portion of the EC_7 maximum discharge power length interval, which is:

[0475] 1 / 3+(500+1000+500)×Lrate=1 / 3+2000×2 / (3×4500)=17 / 27;

[0476] The right bottom of the blue part of the EC_8 maximum discharge power length interval is:

[0477] 1 / 3+(500+1000+500+1000)×Lrate=1 / 3+3000×2 / (3×4500)=7 / 9;

[0478] The area of the blue part of the EC_8 maximum discharge power length interval is:

[0479] (17 / 27+7 / 9)×1000÷2=703.70 (keep two decimal places).

[0480] Calculate the area of the blue portion of the EC_9 maximum discharge power length interval:

[0481] The left bottom of the blue portion of the EC_9 maximum discharge power length interval is the same as the right bottom of the blue portion of the EC_8 maximum discharge power length interval, which is:

[0482] 1 / 3+(500+1000+500+1000)×Lrate=1 / 3+3000×2 / (3×4500)=7 / 9;

[0483] The right bottom of the blue part of the EC_9 maximum discharge power length interval is:

[0484] 1 / 3+(500+1000+500+1000+500)×Lrate=1 / 3+3500×2 / (3×4500)=23 / 27;

[0485] The area of the blue part of the EC_9 maximum discharge power length interval is:

[0486] (7 / 9+23 / 27)×500÷2=407.40 (keep two decimal places).

[0487] Calculate the area of the blue part of the EC_10 interval:

[0488] The left bottom of the blue portion of the EC_10 maximum discharge power length interval is the same as the right bottom of the blue portion of the EC_9 maximum discharge power length interval, which is:

[0489] 1 / 3+(500+1000+500+1000+500)×Lrate=1 / 3+3500×2 / (3×4500)=23 / 27;

[0490] The right bottom of the blue part of the EC_10 maximum discharge power length interval is:

[0491] 1 / 3+(500+1000+500+1000+500+1000)×Lrate=1 / 3+4500×2 / (3×4500)=1;

[0492] The area of the blue part of the EC_10 maximum discharge power length interval is:

[0493] (23 / 27+1)×1000÷2=925.92 (keep two decimal places).

[0494] Therefore, the discharge power allocated to each energy storage container is:

[0495] EC_5:185.18W; EC_6:481.48W; EC_7:296.92W; EC_8:703.70W; EC_9:407.40W; EC_10:925.92W.

[0496] Calculate the values using the indirect common divisor method:

[0497] The maximum charging power of each energy storage container is 500W, 1000W, 500W, 1000W, 500W, and 1000W respectively, and the greatest common divisor of the maximum discharge power is 500.

[0498] Use 500 as the interval unit and split again Figure 26 ,get Figure 27 Because the area of the blue part is 3000, the length of the right bottom BD is 1, and the length of CD is 4500.

[0499] Use the formula in the algorithm to calculate the EC length:

[0500] EC length = 2 × Pinst / DisChaLimitTotalP - 1 = 2 × 3000 / 4500 - 1 = 1 / 3;

[0501] Take the leftmost two ends of the trapezoid as shown in the attached Figure 9 , add some auxiliary lines.

[0502] The area of the blue part of the common divisor interval 1 = the area of the rectangle below + the area of the triangle above;

[0503] The area of the blue part of the common divisor interval 2 = the area of the lower rectangle + the area of the upper triangle + the area tolerance;

[0504] The area of the blue part of the common divisor interval 3 = the area of the lower rectangle + the area of the upper triangle + 2 × area tolerance;

[0505] The area of the blue part of the common divisor interval 4 = the area of the lower rectangle + the area of the upper triangle + 3 × area tolerance;

[0506] The area of the blue part of the common divisor interval 5 = the area of the lower rectangle + the area of the upper triangle + 4 × area tolerance;

[0507] The area of the blue part of the common divisor interval 6 = the area of the lower rectangle + the area of the upper triangle + 5 × area tolerance;

[0508] The area of the blue part of the common divisor interval 7 = the area of the lower rectangle + the area of the upper triangle + 6 × area tolerance;

[0509] The area of the blue part of the common divisor interval 8 = the area of the lower rectangle + the area of the upper triangle + 7 × area tolerance;

[0510] The area of the blue part of the common divisor interval 9 = the area of the lower rectangle + the area of the upper triangle + 8 × area tolerance;

[0511] The area of the upper triangle is half of the tolerance area. Let the tolerance area be Stol. The area of all common divisor intervals can be expressed as:

[0512] S1 = area of the lower rectangle + (1-1 / 2) × Stol; S2 = area of the lower rectangle + (2-1 / 2) × Stol;

[0513] S3 = area of the lower rectangle + (3-1 / 2) × Stol; S4 = area of the lower rectangle + (4-1 / 2) × Stol;

[0514] S5 = area of the lower rectangle + (5-1 / 2) × Stol; S6 = area of the lower rectangle + (6-1 / 2) × Stol;

[0515] S7 = area of the lower rectangle + (7-1 / 2) × Stol; S8 = area of the lower rectangle + (8-1 / 2) × Stol;

[0516] S9 = area of the rectangle below + (9-1 / 2) × Stol;

[0517] S1+S2+S3+S4+S5+S6+S7+S8+S9=Pinst;

[0518] Pinst=9×area of the rectangle below+(1+2+3+4+5+6+7+8+9-9 / 2)×Stol;

[0519] The area of the lower rectangle is the EC length × the maximum discharge power tolerance k;

[0520] 1 / 3×500=500 / 3;

[0521] The value of Pinst is equal to 3000, 3000 = 9 × 500 / 3 + 40.5 × Stol, Stol = 37.03 (keep two decimal places);

[0522] Substitute the area tolerance into each common divisor interval to obtain the area formula of the blue part:

[0523] S1=500 / 3+(1-1 / 2)Stol=500 / 3+37.03×1 / 2=185.17;

[0524] S2=500 / 3+(2-1 / 2)Stol=500 / 3+37.03×3 / 2=222.20;

[0525] S3=500 / 3+(3-1 / 2)Stol=500 / 3+37.03×5 / 2=259.23;

[0526] S4=500 / 3+(4-1 / 2)Stol=500 / 3+37.03×7 / 2=296.26;

[0527] S5=500 / 3+(5-1 / 2)Stol=500 / 3+37.03×9 / 2=333.29;

[0528] S6=500 / 3+(6-1 / 2)Stol=500 / 3+37.03×11 / 2=370.32;

[0529] S7=500 / 3+(7-1 / 2)Stol=500 / 3+37.03×13 / 2=407.35;

[0530] S8=500 / 3+(8-1 / 2)Stol=500 / 3+37.03×15 / 2=444.38;

[0531] S9=500 / 3+(9-1 / 2)Stol=500 / 3+37.03×17 / 2=481.41;

[0532] like Figure 27As shown, because the EC_5 discharge maximum power length interval contains the common divisor interval 1, the area of the blue part of the EC_5 discharge maximum power length interval is 185.17; because the EC_6 discharge maximum power length interval contains the common divisor intervals 2 and 3; therefore, the area of the blue part of the EC_6 discharge maximum power length interval is 222.20+259.23=481.43; similarly, the area of the blue part of the EC_7 discharge maximum power length interval is the blue part of the common divisor interval 4, which is 296.26; the area of the blue part of the EC_8 discharge maximum power length interval is 333.29+370.32=703.61; because the EC_9 discharge maximum power length interval contains the common divisor interval 7, the area of the blue part of the EC_9 discharge maximum power length interval is 407.35; the area of the blue part of the EC_10 is 444.38+481.41=925.79;

[0533] Therefore, the discharge power allocated to each energy storage container is: EC_5: 185.17W; EC_6: 481.43W; EC_7: 296.26W; EC_8: 703.61W; EC_9: 407.35W; EC_10: 925.79W;

[0534] The results calculated by the two methods are roughly the same (because only two decimal places are retained during the calculation process, some precision is lost, so the results of the two calculations will not be exactly the same).

[0535] The algorithm of the present invention includes the following contents in both consistent and differentiated energy storage container power allocation: (1) grouping the energy storage containers according to their current SOC; (2) selecting the group that meets the command power requirement, and then selecting half of the unselected groups, the half with a larger current SOC during discharge and the half with a smaller current SOC during charge, into the optional range. This is done to solve two problems:

[0536] (1) If only the ones that meet the command power requirements are selected, the power value allocated to each energy storage container will be relatively large. In this way, the energy storage container with a higher current SOC will be fully charged too early during charging, and the energy storage container with a lower current SOC will be discharged too early during discharging. In this way, the maximum charging and discharging power limit that can be received by the entire energy storage station will be reduced. If a larger power command comes again, some charging and discharging power will be lost.

[0537] (2) If you simply select the containers that meet the command power and then select a few more unselected containers, another problem will arise. For example, there are 10 containers, the maximum charging and discharging power is 100w, and the current SOC values are 10, 10, 20, 20, 85, 85, 85, 85, 85, 85. The command power is 400w for charging. After selecting 10, 10, 20, 20, and then selecting some of the unselected energy storage containers, the container with a current SOC of 85 will be selected, which will again cause the problem described in (1). Therefore, the energy storage containers are grouped according to the current SOC. Even if the above situation occurs after grouping, after selecting the group that meets the conditions, select two groups upwards. These two groups will be empty, which will not cause the container to be filled too early. The grouping operation is to select containers with similar current SOC states as much as possible when selecting containers.

[0538] An energy storage container uses a consistent energy storage container charging and discharging power allocation algorithm when the maximum charging power and the maximum discharging power of all energy storage containers are consistent.

[0539] An energy storage container uses a differential energy storage container charging and discharging power allocation algorithm when the maximum charging power and the maximum discharging power of all energy storage containers are consistent or inconsistent and supports dynamic change of the maximum charging and discharging power of the energy storage containers.

[0540] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for distributing charging and discharging power at an energy storage station, characterized in that: The following steps are involved: S1: Obtaining a dispatch instruction issued by a dispatch center, wherein the dispatch instruction includes a charging instruction and a discharging instruction; S2: Determine the scheduling instruction; S21: If the dispatch instruction is a charging instruction, execute the consistent charging power allocation algorithm or the differentiated charging power allocation algorithm to reallocate power to the energy storage container; S22: If the dispatch instruction is a discharge instruction, a consistent discharge power allocation algorithm or a differential discharge power allocation algorithm is executed to reallocate power to the energy storage container; In S21, when executing the consistent charging power distribution algorithm, the following steps are specifically included: S211: obtaining the current SOC of all energy storage containers during charging; S212: Eliminate the situation where the current SOC is greater than the upper limit of the maximum charging SOC The number of energy storage containers that can be selected is n, n≤N, where N is the number of all energy storage containers in the energy storage station. The maximum charging power of each energy storage container is UnitChargeLimitP, the maximum discharging power is UnitDisChaLimitP, and the maximum charging SOC limit is , the minimum discharge SOC lower limit is ; S213: Group the n selectable energy storage containers according to the current SOC size, with a grouping step of F and a grouping number of X, where X is rounded up, where X= / F, groups are sorted from low to high according to the SOC value range, and the group number range is 1, 2, ..., X; S214: Calculate the total maximum charging power of each group of energy storage containers, and then accumulate the maximum charging power of each group from the group with a low SOC value range to the group with a high SOC value range, until the accumulated maximum charging power of each group is greater than or equal to the command power Pinst. At this time, the group participating in the accumulation is in the group selection range that meets the minimum power of the energy storage container under the command, and the maximum group number is set to , the number of groups not in the range is , then the group selected to participate in power allocation is 1~ + ( ) / 2 rounded down; If the accumulated maximum charging power of all groups is still less than the command power Pinst after all groups are accumulated, each energy storage container can be instructed to charge according to the maximum charging power of the energy storage container; S215: The number of currently selected energy storage containers is nSelected, and the average power of each energy storage container is ; If Pavg≤UnitChargeLimitP / 2, the power allocated to the energy storage container with the largest current SOC is 0; If Pavg>UnitChargeLimitP / 2, the power allocated to the energy storage container with the minimum current SOC is the maximum charging power UnitChargeLimitP; In S215, the selected energy storage containers are sorted from largest to smallest according to the current SOC, and the power value allocated to each energy storage container is an arithmetic progression; In S21, when executing the differential charging power allocation algorithm, the following steps are specifically included: S21.1: When a charging command is received, obtain the current SOC and maximum charging power of all energy storage containers; S21.2: Exclude the current SOC from being greater than the maximum SOC limit for charging The number of energy storage containers available for selection is n, n≤N, where N is the number of all energy storage containers in the energy storage station, and the maximum SOC limit of each energy storage container is , the minimum discharge SOC lower limit is ; S21.3: Group the available energy storage containers according to the current SOC size, with a grouping step of F; the number of groups is X, and X is rounded up, where X= / F; groups are sorted from low to high according to the SOC value range, and the group number value range is 1, 2, ..., X; S21.4: Calculate the total maximum charging power of each group of energy storage containers, and then accumulate the maximum charging power of each group from the group with a low SOC value range to the group with a high SOC value range, until the accumulated maximum charging power of each group is greater than or equal to the command power Pinst. At this time, the group participating in the accumulation is the group selection range that meets the minimum power of the energy storage container under the command, and the maximum group number is set to , the number of groups not in the range is , then the group selected to participate in power allocation is 1~ + ( ) / 2 rounded down; If the accumulated maximum charging power of all groups is still less than the command power Pinst after all groups are accumulated, the energy storage container can be selected to issue a command according to the maximum charging power of each energy storage container; S21.5: The number of currently selected energy storage containers is nSelected. The energy storage containers are sorted according to the current SOC size, and the allocated power value of each energy storage container is calculated; When calculating the allocated power value of each energy storage container in S21.5, the energy storage containers are sorted according to the current SOC and then plotted, and the power value allocated to each energy storage container is calculated using the direct area method or the indirect common divisor area method.

2. The method for distributing charging and discharging power of an energy storage station according to claim 1, characterized in that: If Pavg ≤ UnitChargeLimitP / 2, the power allocated to the energy storage container with the highest current SOC is 0. The number of elements in the arithmetic sequence is the number of currently selected energy storage containers, nSelected, with an average value of Pavg and a minimum value of 0. Calculate the values of each element in the arithmetic sequence and then sort the energy storage containers according to their current SOC. The larger the current SOC, the smaller the allocated power. This is how the power is allocated to each energy storage container. If Pavg > UnitChargeLimitP / 2, the power allocated to the energy storage container with the smallest current SOC is UnitChargeLimitP. The number of elements in the arithmetic sequence is the number of currently selected energy storage containers, nSelected. The average value is Pavg, and the maximum value is UnitChargeLimitP. Calculate the values of each element in the arithmetic sequence, and then sort the energy storage containers according to the current SOC. The larger the current SOC, the smaller the allocated power. The power is then allocated to each energy storage container.

3. The method for distributing charging and discharging power of an energy storage station according to claim 1, characterized in that: In S22, when executing the consistent discharge power allocation algorithm, the following steps are specifically included: S221: obtaining the current SOC of all energy storage containers during discharge; S222: Exclude the current SOC from being less than the minimum discharge SOC lower limit The number of energy storage containers that can be selected is n, n≤N, where N is the number of all energy storage containers in the energy storage station. The maximum charging power of each energy storage container is UnitChargeLimitP, the maximum discharging power is UnitDisChaLimitP, and the maximum charging SOC limit is , the minimum discharge SOC lower limit is ; S223: Group the n selectable energy storage containers according to the current SOC, with a grouping step of F and a grouping number of X, where X is rounded up to an integer, where X=( ) / F, the groups are sorted from high to low according to the SOC value range, and the group number range is 1, 2, ..., X; S224: Calculate the total maximum discharge power of each group of energy storage containers, and then accumulate the maximum discharge power of each group from the group with a high SOC value range to the group with a low SOC value range, until the accumulated maximum discharge power of each group is greater than or equal to the command power Pinst. At this time, the group participating in the accumulation is in the group selection range that meets the minimum power of the energy storage container under the command, and the maximum group number is set to , the number of groups not in the range is , then the group selected to participate in power allocation is 1~ + ( ) / 2 rounded down; If the maximum discharge power of the accumulated group is still less than the command power Pinst after all groups are accumulated, the energy storage container can be selected to issue a command according to the maximum discharge power of the energy storage container; S225: The number of currently selected energy storage containers is nSelected, and the average power of each energy storage container is ; If Pavg≤UnitDisChaLimitP / 2, the power allocated to the energy storage container with the lowest current SOC is 0; If Pavg>UnitDisChaLimitP / 2, the power allocated to the energy storage container with the current maximum SOC is the maximum discharge power UnitDisChaLimitP.

4. The method for distributing charging and discharging power of an energy storage station according to claim 3, characterized in that: In S225 , the selected energy storage containers are sorted from small to large according to the current SOC, and the power allocated to each energy storage container is an arithmetic progression.

5. The method for distributing charging and discharging power of an energy storage station according to claim 4, characterized in that: If Pavg ≤ UnitDisChaLimitP / 2, the power allocated to the energy storage container with the lowest current SOC is 0. The number of elements in the arithmetic sequence is the number of currently selected energy storage containers, nSelected, with an average value of Pavg and a minimum value of 0. Calculate the values of each element in the arithmetic sequence and then sort the energy storage containers according to their current SOC. The larger the current SOC, the greater the allocated power. This power is then allocated to each energy storage container. If Pavg>UnitDisChaLimitP / 2, the power allocated to the energy storage container with the largest current SOC is UnitDisChaLimitP. The number of elements in the arithmetic sequence is the number of currently selected energy storage containers, nSelected. The average value is Pavg, and the maximum value is UnitDisChaLimitP. The values of each element in the arithmetic sequence are calculated, and then the energy storage containers are sorted according to the current SOC. The larger the current SOC, the greater the allocated power. The power is then allocated to each energy storage container.

6. The method for distributing charging and discharging power of an energy storage station according to claim 1, characterized in that: In S22, when the differential discharge power allocation algorithm is executed, the following steps are specifically included: S22.1: When a discharge command is received, the current SOC and maximum discharge power of all energy storage containers are obtained; S22.2: Exclude the current SOC from being less than the minimum discharge SOC lower limit The number of energy storage containers available for selection is n, n≤N, where N is the number of all energy storage containers in the energy storage station, and the maximum SOC limit of each energy storage container is , the minimum discharge SOC lower limit is ; S22.3: Group the selectable energy storage containers according to their current SOC size, with a grouping step of F; The number of groups is X, X is rounded up, where X=(100- ) / F; the groups are sorted from high to low according to the SOC value range, and the group number value range is 1, 2, ..., X; S22.4: Calculate the total maximum discharge power of each group of energy storage containers, and then accumulate the maximum discharge power of each group from the group with a high SOC value range to the group with a low SOC value range, until the accumulated maximum discharge power of each group is greater than or equal to the command power Pinst. At this time, the group participating in the accumulation is within the group selection range of the energy storage container with the minimum power under the command, and the maximum group number is set to , the number of groups not in the range is X- , then the group selected to participate in power allocation is 1~ + ( ) / 2 rounded down; If the maximum discharge power of the accumulated group is still less than the command power Pinst after all groups are accumulated, the energy storage container can be selected to issue a command according to the maximum discharge power of each energy storage container; S22.5: The number of currently selected energy storage containers is nSelected. The energy storage containers are sorted according to the current SOC, and the power value allocated to each energy storage container is calculated.

7. The method for distributing discharge power of an energy storage station according to claim 6, characterized in that: When calculating the power value allocated to each energy storage container in S22.5, the energy storage containers are sorted according to the current SOC and then plotted, and the power value allocated to each energy storage container is calculated using the direct area method or the indirect common divisor area method.

8. An energy storage container, characterized in that: By adopting the method for distributing charging and discharging power for an energy storage station as described in any one of claims 1 to 7, the maximum charging power and the maximum discharging power of all energy storage containers using this method are consistent.

9. An energy storage container, characterized in that: A method for allocating charging and discharging power for an energy storage station as described in any one of claims 1 to 7 is adopted, wherein the maximum charging power and the maximum discharging power of all energy storage containers using this method are consistent or inconsistent, and the method supports dynamic changes in the maximum charging power and the maximum discharging power of the energy storage containers.

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