Multi-energy storage secondary frequency modulation power distribution method and device, and electronic equipment

Abstract

The present invention discloses a multi-energy storage secondary frequency modulation power distribution method, device, and electronic device. The method includes: taking the principle of balancing the bidirectional output capacity of the energy storage power station, calculating six SOC thresholds corresponding to each energy storage power station according to the charge-discharge efficiency of each energy storage power station, dividing five SOC intervals according to the six SOC thresholds, and calculating the charge-discharge power that all energy storage units can jointly bear within the five SOC intervals; according to the command requirements of the regional power grid at a certain moment, combining the charge-discharge capabilities of different SOC intervals, determining the charge-discharge priorities of the five SOC intervals at the current moment and the only SOC interval that needs to apply the optimization algorithm to distribute power, and for the remaining four SOC intervals, there is no need to apply the algorithm to distribute power; for the SOC interval that needs to apply the optimization algorithm to distribute power at the current moment, different power distribution algorithms are selected according to different SOC intervals. While ensuring the bidirectional output capacity of the multi-energy storage power station, the total cost of secondary frequency modulation is minimized as much as possible.

Description

Technical Field

[0001] The present application relates to the technical field of frequency modulation control of energy storage power stations, and specifically relates to a multi-energy storage secondary frequency modulation power distribution method, device, and electronic equipment. Background Art

[0002] For traditional power systems, power production and power consumption are balanced in real time. The emergence of energy storage technology enables the power system to transform from "rigid" to "flexible", thus solving the problems of insufficient damping and inertia support capabilities of new energy power generation. By leveraging the charging and discharging characteristics of energy storage systems and through large-scale decentralized layout and operation regulation of large-scale energy storage power stations, the consumption and transmission capabilities of new energy can be effectively enhanced.

[0003] In the literature ["Power distribution strategy for battery energy storage unit groups participating in secondary frequency modulation of power systems" [J]. Automation of Electric Power Systems, 2020, 44(14): 26-34] published by Yan Gangui et al., the influence of the charging and discharging power of energy storage units on their energy conversion efficiency was analyzed, a charging and discharging power-efficiency model of battery energy storage units was constructed, and a power distribution strategy for battery energy storage unit groups that maximizes the overall energy conversion efficiency of the battery energy storage power station was proposed. However, it only considered the energy conversion efficiency, ignored other costs during the operation of the energy storage power station, and did not consider the coordinated operation between different types of energy storage power stations in the actual power system.

[0004] In the literature ["Two-layer optimization of frequency modulation power for multi-energy storage systems considering frequency modulation cost and state of charge restoration" [J]. Proceedings of the CSEE, 2021, 41(23): 8020-8033] published by Li Junhui et al., a two-layer optimization strategy for frequency modulation power of multi-energy storage systems considering frequency modulation cost and SOC restoration was proposed. A resistance coefficient related to the remaining frequency modulation capacity of the energy storage power station was introduced in the frequency modulation power optimization layer to jointly form the objective function with the frequency modulation cost, and frequency modulation power optimization distribution was achieved according to the frequency modulation costs and remaining frequency modulation capabilities of different types of energy storage power stations; in the SOC optimization layer, an SOC weight was introduced to redistribute the frequency modulation power optimization results with the goal of restoring the SOC of energy storage units. However, it represented the charging and discharging power demand of the energy storage power station with the remaining frequency modulation capacity, ignored the SOC differences among different energy storage units within a single energy storage power station, and in the working condition where the overall SOC state of the energy storage power station was not healthy enough, this control strategy still took the product of the frequency modulation cost and the remaining frequency modulation capacity as the optimization goal to complete the initial power distribution, and could not effectively improve the two-way output capacity of the energy storage power station. In addition, this control strategy used a two-layer structure for power optimization, and the output power of each energy storage unit was a separate decision variable, resulting in a large amount of calculation and a slow power distribution speed.

[0005] Therefore, it is necessary to propose a multi-energy storage secondary frequency modulation power distribution method that can balance economic benefits and two-way output capacity and quickly achieve power distribution under the condition that the SOC state of the SOC is not healthy enough. Summary of the Invention

[0006] Aiming at the problem that the energy storage power station considering economic benefits under the above double-layer optimization strategy may not be able to balance the two-way output capacity of the energy storage power station, the embodiment of the present invention provides a multi-energy storage secondary frequency modulation power distribution method that balances economic benefits and two-way output capacity. According to the charge and discharge efficiency of each energy storage unit, five corresponding SOC intervals are calculated. For the energy storage units in different intervals, different algorithms are used to complete power distribution, so as to solve the technical problems in the related art that only economic benefits can be guaranteed but the two-way output capacity of the energy storage power station cannot be effectively improved and the power distribution speed is slow under the condition that the SOC state is not healthy enough.

[0007] According to the first aspect of the embodiment of the present application, a multi-energy storage secondary frequency modulation power distribution method is provided, including:

[0008] S1: Based on the principle of balancing the two-way output capacity of the energy storage power station, calculate six corresponding SOC thresholds for each energy storage power station according to its charge and discharge efficiency. The six SOC thresholds are the minimum value, the charging transition value, the charging equilibrium value, the discharging equilibrium value, the discharging transition value, and the maximum value. Among them, the energy storage units with SOC values between the minimum value and the charging transition value form a low-power SOC interval, the energy storage units with SOC values between the charging transition value and the charging equilibrium value form a low-power transition SOC interval, the energy storage units with SOC values between the charging equilibrium value and the discharging equilibrium value form an equilibrium SOC interval, the energy storage units with SOC values between the discharging equilibrium value and the discharging transition value form a high-power transition SOC interval, and the energy storage units with SOC values between the discharging transition value and the maximum value form a high-power SOC interval. Then calculate the charge and discharge power that all energy storage units in the five SOC intervals can jointly bear;

[0009] S2: According to the command requirements of the regional power grid at a certain moment, combined with the charge and discharge capabilities of different SOC intervals, determine the charge and discharge priorities of the five SOC intervals at the current moment and the only SOC interval that needs to apply the optimization algorithm to distribute power. For the other four SOC intervals that do not need to apply the algorithm to distribute power, if the charge and discharge priority of this SOC interval is higher than the SOC interval that needs to apply the optimization algorithm to distribute power, then all energy storage units in this SOC interval output the rated power. If the charge and discharge priority of this interval is lower than the SOC interval that needs to apply the optimization algorithm to distribute power, then the output power of all energy storage units in this interval is 0;

[0010] S3: For the SOC intervals that need to apply the optimization algorithm to allocate power at the current moment, different power allocation algorithms are selected according to different SOC intervals, specifically including: 1) For all energy storage units in the high-SOC interval and low-SOC interval, the power is allocated with the best overall SOC of multiple energy storage power stations as the main optimization goal. At the same time, an SOC optimization dead zone is designed to take into account the economic benefits of frequency modulation; 2) For all energy storage units in the low-SOC transition interval and high-SOC transition interval, the cost-SOC sorting model is applied to allocate power; 3) For all energy storage units in the balanced SOC interval, the power is allocated with the best economic benefits of multiple energy storage power stations participating in frequency modulation as the main optimization goal. At the same time, a cost optimization dead zone is designed to take into account the overall SOC.

[0011] Further, in S1, six SOC thresholds corresponding to each energy storage power station are calculated according to the charge-discharge efficiency, including:

[0012] Considering that the degree of change in the SOC of the energy storage unit caused by the same-sized charge command and discharge command is different, the following constraint relationships exist among the six threshold variables:

[0013]

[0014] Where: S min,i 、S low,i 、S perfect,c,i 、S perfect,d,i 、S high,i 、S max,i are respectively the minimum value, charge transition value, charge balance value, discharge balance value, discharge transition value, and maximum value of the SOC of the energy storage units inside the energy storage power station i, and η i is the charge-discharge efficiency of the energy storage power station i;

[0015] Define the S flag matrix to describe the SOC intervals where all energy storage units are located:

[0016]

[0017] Where: S flag,i,j is a variable representing the state interval where the energy storage unit j inside the energy storage power station i is located. From 1 to 5, they are the low-SOC interval, low-SOC transition interval, balanced SOC interval, high-SOC transition interval, and high-SOC interval in turn.

[0018] Further, in S3, for all energy storage units in the high-SOC interval and low-SOC interval, the power is allocated with the best overall SOC of multiple energy storage power stations as the main optimization goal. At the same time, an SOC optimization dead zone is designed to take into account the economic benefits of frequency modulation, including:

[0019] Define two basic objective functions according to the following equations:

[0020]

[0021] Where: S i,j (t) is the SOC value of the energy storage unit at the current moment, S perfect,i is the ideal SOC value of energy storage power station i, is the total frequency modulation cost of energy storage power station i at the current moment, Z1 is the basic objective function representing the overall SOC of multiple energy storage power stations, and Z2 is the basic objective function representing the economic benefit of frequency modulation;

[0022] Combine the two basic objective functions into a new single objective function according to the following equations:

[0023] Z = α z,soc ·Z1 + α z,cost ·Z2

[0024] Where: α z,soc is the SOC weight factor, α z,cost is the economic benefit weight factor. By changing the values of the two weight factors, the priority of each energy storage unit participating in the output during the power distribution process can be changed;

[0025] Add the following constraints to reduce the numerical difference between the two objective functions:

[0026]

[0027] Where: Z esm,2 is the estimated value of Z2, and Z esm,1 is the estimated value of Z1.

[0028] Furthermore, the estimation method of the estimated value is as follows:

[0029] First, set all energy storage units to assume power according to the rated power, that is, distribute power proportionally, and then calculate Z1 and Z2 under this power distribution scheme to obtain two estimated values; D in the above formula is the proportionality coefficient, representing the difference in the degree of emphasis on the two basic objectives. When distributing power for the high SOC interval and the low SOC interval, the value of D is much greater than 1.

[0030] Furthermore, for all energy storage units in the low SOC transition interval and the high SOC transition interval, apply the cost-SOC sorting model to distribute power, including:

[0031] 1) Arrange according to the size of SOC, and then determine the energy storage unit with the smallest SOC and its corresponding charging interval. The minimum value of the charging interval is the minimum SOC value S1, and the maximum value S2 is obtained according to the following equation:

[0032]

[0033] Among them, P N,1 (t), η1, E N,1 are respectively the rated power, charging efficiency, and rated capacity corresponding to the energy storage unit with the minimum SOC. The energy storage units within the charging interval are all the energy storage units in the multi-energy storage power station with SOC values between S1 and S2.

[0034] 2) Compare P sum with the magnitude of the charging instruction. P sum is the sum of the rated powers of all energy storage units in the charging interval. If the charging instruction is larger, the minimum energy storage unit charges at its rated power, and this energy storage unit no longer participates in subsequent distribution. After subtracting the rated power of this energy storage unit from the charging instruction, a new charging instruction is obtained, and the energy storage units are sorted in ascending order according to the size of SOC again. The above logic is looped until the value of P sum is greater than the value of the charging instruction;

[0035] 3) When the sum of the rated powers is greater than the value of the charging instruction, calculate the product of the SOC and the estimated cost of the energy storage units within the interval, and then sort them in ascending order to determine the priority. The energy storage units within the charging interval are charged in sequence according to the priority. For the energy storage units with higher priority, if the output rated power still cannot fully meet the charging instruction, then this energy storage unit outputs at its rated power;

[0036] Among them, the cost of each energy storage unit within the charging interval is estimated according to the following formula:

[0037]

[0038] Among them, c e is the on-grid electricity price, c milinv,i , P N,i , E N,i , N 0,i are respectively the unit power cost, rated power, rated capacity, and equivalent cycle times of the i-th energy storage power station.

[0039] Similarly, power distribution is performed for the high-SOC transition interval under the charging condition, the low-SOC transition interval under the discharging condition, and the high-SOC transition interval under the discharging condition.

[0040] Furthermore, in S3, for all the energy storage units in the balanced SOC interval, with the best economic benefit of the multi-energy storage power station participating in frequency modulation as the main optimization goal, power is distributed, and at the same time, a cost optimization dead zone is designed, taking into account the overall SOC, including:

[0041] Define two basic objective functions according to the following formula:

[0042]

[0043] Wherein: S i,j (t) is the SOC value of the energy storage unit at the current moment, and S perfect,i is the ideal SOC value of the energy storage power station i, is the total frequency modulation cost of the energy storage power station i at the current moment, Z1 is the basic objective function representing the overall SOC of multiple energy storage power stations, and Z2 is the basic objective function representing the economic benefits of frequency modulation;

[0044] According to the following formula, the two basic objective functions are combined into a new single objective function:

[0045] Z = α z,soc ·Z1 + α z,cost ·Z2

[0046] Wherein: α z,soc is the SOC weight factor, and α z,cost is the economic benefit weight factor. By changing the values of the two weight factors, the priority of each energy storage unit participating in the output during the power distribution process can be changed.

[0047] Add the following constraints to reduce the numerical difference between the two objective functions:

[0048]

[0049] Wherein: Z esm,2 is the estimated value of Z2, and Z esm,1 is the estimated value of Z1.

[0050] Furthermore, the estimation method of the estimated value is as follows: First, set all energy storage units to assume power according to the size of the rated power, that is, distribute power proportionally, and then calculate Z1 and Z2 under this power distribution scheme to obtain two estimated values; D in the above formula is a proportionality coefficient, representing the difference in the degree of emphasis on the two basic objectives. When distributing power for the balanced SOC interval, the value of D is much less than 1.

[0051] According to the second aspect of the embodiments of the present application, a multi-energy storage secondary frequency modulation power distribution device is provided, including:

[0052] The SOC interval division module is used to calculate six corresponding SOC thresholds for each energy storage power station based on the principle of balancing the bidirectional output capacity of the energy storage power station. The six SOC thresholds are the minimum value, the charging transition value, the charging equilibrium value, the discharging equilibrium value, the discharging transition value, and the maximum value. Among them, the energy storage units with SOC values between the minimum value and the charging transition value form the low-power SOC interval, the energy storage units with SOC values between the charging transition value and the charging equilibrium value form the low-power transition SOC interval, the energy storage units with SOC values between the charging equilibrium value and the discharging equilibrium value form the equilibrium SOC interval, the energy storage units with SOC values between the discharging equilibrium value and the discharging transition value form the high-power transition SOC interval, and the energy storage units with SOC values between the discharging transition value and the maximum value form the high-power SOC interval. Then, calculate the charging and discharging power that all energy storage units in the five SOC intervals can jointly bear;

[0053] The SOC interval power preliminary distribution module is used to determine the charging and discharging priorities of the five SOC intervals at the current moment and the SOC interval that uniquely needs to apply the optimization algorithm to distribute power according to the command requirements of the regional power grid at a certain moment and the charging and discharging capabilities of different SOC intervals. For the other four SOC intervals that do not need to apply the algorithm to distribute power, if the charging and discharging priority of this SOC interval is higher than the SOC interval that needs to apply the optimization algorithm to distribute power, then all energy storage units in this SOC interval output the rated power. If the charging and discharging priority of this interval is lower than the SOC interval that needs to apply the optimization algorithm to distribute power, then the power output of all energy storage units in this interval is 0;

[0054] The SOC interval power distribution optimization algorithm module is used to select different power distribution algorithms according to different SOC intervals for the SOC interval that needs to apply the optimization algorithm to distribute power at the current moment. Specifically, it includes: 1) For all energy storage units in the high-power SOC interval and the low-power SOC interval, the power is distributed with the main optimization goal of the best overall SOC of multiple energy storage power stations. At the same time, an SOC optimization dead zone is designed to take into account the economic benefits of frequency modulation; 2) For all energy storage units in the low-power transition SOC interval and the high-power transition SOC interval, the cost-SOC sorting model is applied to distribute power; 3) For all energy storage units in the equilibrium SOC interval, the power is distributed with the main optimization goal of the best economic benefits of multiple energy storage power stations participating in frequency modulation. At the same time, a cost optimization dead zone is designed to take into account the overall SOC.

[0055] According to the third aspect of the embodiments of the present application, an electronic device is provided, including:

[0056] One or more processors;

[0057] A memory for storing one or more programs;

[0058] When the one or more programs are executed by the one or more processors, the one or more processors implement the method as described in the first aspect.

[0059] According to a fourth aspect of the embodiments of the present application, there is provided a computer-readable storage medium, on which computer instructions are stored, and when the instructions are executed by a processor, the steps of the method as described in the first aspect are implemented.

[0060] The technical solutions provided by the embodiments of the present application may include the following beneficial effects:

[0061] As can be seen from the above embodiments, the present application uses five SOC intervals to distinguish different energy storage units, can accurately judge the charging and discharging requirements of each energy storage unit, and thus accurately allocate charging and discharging power to the corresponding energy storage unit in combination with the command requirements of the regional power grid at the current moment to help it improve its own SOC state during the participation in secondary frequency modulation, effectively improving the two-way output capacity of the energy storage power station;

[0062] The present application combines two basic objective functions representing the overall SOC and the economic benefits of frequency modulation into a new single objective function. When the command of the regional power grid changes each time, the control center only needs to perform one optimal solution to obtain the power distribution result. At the same time, only the output power of the energy storage units within the SOC interval that needs to apply the optimization algorithm to allocate power is selected as the decision variable for the optimal solution, thereby greatly reducing the calculation amount and improving the speed of power distribution.

[0063] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] The accompanying drawings herein are incorporated into the specification and form a part of the specification, showing embodiments consistent with the present application and used together with the specification to explain the principles of the present application.

[0065] Figure 1 is a flowchart of a multi-energy storage secondary frequency modulation power distribution method shown according to an exemplary embodiment.

[0066] Figure 2 is a flowchart of a multi-energy storage secondary frequency modulation power distribution that takes into account economic benefits and two-way output capacity according to an embodiment of the present invention.

[0067] Figure 3 is a flowchart of a power distribution algorithm for the high and low power transition intervals according to an embodiment of the present invention.

[0068] Figure 4 is a graph of the output simulation results of a multi-energy storage power station according to an example of the present invention.

[0069] Figure 5 Multi - state interval quantity simulation result diagram according to an example of the present invention.

[0070] Figure 6 Power output simulation result diagram of an energy storage power station with different battery types according to an example of the present invention.

[0071] Figure 7 It is a block diagram of a multi - energy storage secondary frequency regulation power distribution device shown according to an exemplary embodiment. Detailed implementation manners

[0072] Here, the exemplary embodiments will be described in detail, and the examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all implementation manners consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0073] The terms used in the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms "a", "said", and "the" used in the present application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0074] It should be understood that although the terms first, second, third, etc. may be used in the present application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "when" or "while" or "in response to determining".

[0075] Figure 1 It is a flowchart of a multi - energy storage secondary frequency regulation power distribution method shown according to an exemplary embodiment. As Figure 1 shown, the method may include the following steps:

[0076] S1: Based on the principle of balancing the two-way output capacity of the energy storage power station, calculate the corresponding six SOC thresholds for each energy storage power station. The six SOC thresholds are the minimum value, the charging transition value, the charging equilibrium value, the discharging equilibrium value, the discharging transition value, and the maximum value. Among them, the energy storage units with SOC values between the minimum value and the charging transition value constitute the low-power SOC interval, the energy storage units with SOC values between the charging transition value and the charging equilibrium value constitute the low-power transition SOC interval, the energy storage units with SOC values between the charging equilibrium value and the discharging equilibrium value constitute the equilibrium SOC interval, the energy storage units with SOC values between the discharging equilibrium value and the discharging transition value constitute the high-power transition SOC interval, and the energy storage units with SOC values between the discharging transition value and the maximum value constitute the high-power SOC interval. Then calculate the charging and discharging power that all energy storage units in the five SOC intervals can jointly undertake.

[0077] S2: According to the command requirements of the regional power grid at a certain moment, combined with the charging and discharging capabilities of different SOC intervals, determine the charging and discharging priorities of the five SOC intervals at the current moment and the only SOC interval that needs to apply the optimization algorithm to allocate power. For the other four SOC intervals that do not need to apply the algorithm to allocate power, if the charging and discharging priority of this SOC interval is higher than that of the SOC interval that needs to apply the optimization algorithm to allocate power, then all energy storage units in this SOC interval output the rated power. If the charging and discharging priority of this interval is lower than that of the SOC interval that needs to apply the optimization algorithm to allocate power, then the output power of all energy storage units in this interval is 0.

[0078] S3: For the SOC interval that needs to apply the optimization algorithm to allocate power at the current moment, select different power allocation algorithms according to different SOC intervals, specifically including: 1) For all energy storage units in the high-power SOC interval and the low-power SOC interval, allocate power with the main optimization goal of the best overall SOC of multiple energy storage power stations, and at the same time design a SOC optimization dead zone to take into account the economic benefits of frequency modulation; 2) For all energy storage units in the low-power transition SOC interval and the high-power transition SOC interval, apply the cost-SOC sorting model to allocate power; 3) For all energy storage units in the equilibrium SOC interval, allocate power with the main optimization goal of the best economic benefits of multiple energy storage power stations participating in frequency modulation, and at the same time design a cost optimization dead zone to take into account the overall SOC.

[0079] As can be seen from the above embodiments, S1 in this application considers the difference in the degree of change of the SOC of the energy storage unit caused by the same-sized charging command and discharging command, and can solve the technical problem that in the working conditions where the SOC state is not healthy enough in the related technology, only the economic benefits can be guaranteed, but the two-way output capacity of the energy storage power station cannot be effectively improved.

[0080] In the present application, S2 directly determines the output power for four SOC intervals by using the charge-discharge priority at a certain moment and the charge-discharge capabilities in different SOC intervals, so that the decision variables for optimal solution only consist of the output power of the energy storage units within one SOC interval, greatly improving the calculation speed.

[0081] In S3 of the present application, different power distribution algorithms are selected according to different SOC intervals to achieve coordinated operation among different energy storage power stations, and on the premise of ensuring relatively healthy SOC, the frequency regulation cost of the energy storage power station is minimized as much as possible.

[0082] As Figure 2 shown is a multi-energy storage secondary frequency regulation power distribution flow chart that takes into account economic benefits and bidirectional output capabilities. Taking the charging condition as an example, the flow chart illustrates how multiple energy storage power stations participating in the secondary frequency regulation of the regional power grid should determine the output power of each energy storage unit according to the AGC command.

[0083] In the specific implementation of S1: Based on the principle of balancing the bidirectional output capabilities of the energy storage power station, six SOC thresholds corresponding to each energy storage power station are calculated according to its charge-discharge efficiency. The six SOC thresholds are the minimum value, charging transition value, charging equilibrium value, discharging equilibrium value, discharging transition value, and maximum value. Among them, the energy storage units with SOC values between the minimum value and the charging transition value form a low-power SOC interval, the energy storage units with SOC values between the charging transition value and the charging equilibrium value form a low-power transition SOC interval, the energy storage units with SOC values between the charging equilibrium value and the discharging equilibrium value form an equilibrium SOC interval, the energy storage units with SOC values between the discharging equilibrium value and the discharging transition value form a high-power transition SOC interval, and the energy storage units with SOC values between the discharging transition value and the maximum value form a high-power SOC interval. Then, the charge-discharge power that all energy storage units can jointly bear within the five SOC intervals is calculated;

[0084] Specifically, first, six variables reflecting the SOC of the energy storage units need to be defined to distinguish different SOC intervals. During the power distribution process, different strategies should be adopted for different SOC intervals. Within one command cycle, the same-sized charging command and discharging command have different degrees of impact on the SOC of the energy storage unit because the port power of the energy storage unit is less than the output power under the charging condition, while the port power of the energy storage unit is greater than the output power under the discharging condition. If 0.5 is considered the optimal value of SOC, it may lead to an imbalance between the charging capacity and discharging capacity of the energy storage power station. To balance the charging capacity and discharging capacity of the energy storage power station as much as possible, that is, to enhance the bidirectional output capabilities of the energy storage power station, the following constraint relationships should exist among the six variables reflecting the SOC of the energy storage units:

[0085]

[0086] Wherein: S min,i 、S low,i 、S perfect,c,i 、S perfect,d,i 、S high,i 、S max,i are respectively the minimum SOC value, charging transition value, charging balance value, discharging balance value, discharging transition value, and maximum value of the energy storage units inside the energy storage power station i. η i is the charge-discharge efficiency of the energy storage power station i.

[0087] According to the above six variables, five state intervals that can participate in the secondary frequency regulation of the regional power grid are divided, and S flag matrix is defined to describe the state intervals where all energy storage units are located:

[0088]

[0089] Wherein: S flag,i,j is a variable representing the state interval where the energy storage unit j inside the energy storage power station i is located. From 1 to 5, they are the low power interval, low power transition interval, balance interval, high power transition interval, and high power interval in sequence.

[0090] The charge-discharge power that all energy storage units can jointly bear in each SOC state interval is of great significance for determining the role played by different state intervals in power distribution at a certain moment. In the actual secondary frequency regulation scenario of the regional power grid, the AGC command is updated every 4 to 6 seconds. At this time, it is necessary to adjust the output power of the energy storage power station according to the updated command. Since the states of each energy storage unit change dynamically with the progress of the charge-discharge process, therefore, it is necessary to re-evaluate the maximum output power of all energy storage units in each state interval every time the command is updated. For this purpose, the following calculation formula is used to calculate the five power boundary values after the command is updated:

[0091]

[0092] Wherein: P1(t), P2(t), P3(t), P4(t), P5(t) respectively represent the charge-discharge power that all energy storage units can jointly bear in the low power interval, low power transition and below interval, balance and below interval, high power transition and below interval, and high power and below interval at a certain moment. P N,i,j is the rated power of the energy storage unit j inside the energy storage power station i.

[0093] The embodiment of S1 can solve the technical problem in the related art that when the SOC state is not healthy enough, only the economic benefit can be guaranteed, but the two-way output capacity of the energy storage power station cannot be effectively improved.

[0094] In the specific implementation of S2: According to the instruction requirements of the regional power grid at a certain moment, combined with the charge and discharge capabilities in different SOC intervals, determine the charge and discharge priorities of the five SOC intervals at the current moment and the SOC interval that uniquely requires the application of an optimization algorithm to allocate power. For the remaining four SOC intervals that do not require the application of an algorithm to allocate power, if the charge and discharge priority of this SOC interval is higher than that of the SOC interval that requires the application of an optimization algorithm to allocate power, then all energy storage units in this SOC interval output the rated power. If the charge and discharge priority of this interval is lower than that of the SOC interval that requires the application of an optimization algorithm to allocate power, then the output power of all energy storage units in this interval is 0;

[0095] Specifically, if the instruction issued by the regional power grid at a certain moment is a charging instruction, then the priorities of each state interval to bear power at this moment from high to low are the low power interval, the low power transition interval, the balanced interval, the high power transition interval, and the high power interval. If the instruction issued by the regional power grid at a certain moment is a discharging instruction, then the priorities of each state interval to bear power at this moment from high to low are the high power interval, the high power transition interval, the balanced interval, the low power transition interval, and the low power interval.

[0096] Determine the SOC interval that uniquely requires the application of an optimization algorithm to allocate power according to the following formula:

[0097]

[0098] where, P AGC (t) is the instruction issued by the regional power grid at the current moment, and the value of S algo (t) represents the SOC interval that uniquely requires the application of an optimization algorithm to allocate power at the moment, and corresponds one-to-one with the five values of S flag,i,j . When it is 0, all energy storage units output the rated power.

[0099] After successfully determining the SOC interval that requires the application of an optimization algorithm to allocate power, for the state interval with a higher priority, all energy storage units output the rated power. For the state interval with a lower priority, the output power of all energy storage units is 0. The purpose of doing this is to ensure that the charge and discharge power of the regional power grid is allocated to the energy storage units that most need to be charged or discharged at the current moment, that is, all energy storage units in the state interval with a higher priority. This is achieved by adding the following constraints:

[0100]

[0101] where, P output,i,j (t) is the output power of the energy storage unit j inside the energy storage power station i at the current moment.

[0102] The embodiments of S2 directly determine the output powers of four SOC intervals, so that the decision variables for optimal solution consist only of the output powers of energy storage units within one SOC interval, greatly improving the calculation speed.

[0103] In the specific implementation of S3: for the SOC intervals where the optimization algorithm needs to be applied to allocate power at the current moment, different power allocation algorithms are selected according to different SOC intervals, specifically including: 1) For all energy storage units in the high-SOC interval and low-SOC interval, power is allocated with the best overall SOC of multiple energy storage power stations as the main optimization goal, and an SOC optimization dead zone is designed to take into account the economic benefits of frequency modulation; 2) For all energy storage units in the low-SOC transition interval and high-SOC transition interval, the cost-SOC sorting model is applied to allocate power; 3) For all energy storage units in the balanced SOC interval, power is allocated with the best economic benefits of multiple energy storage power stations participating in frequency modulation as the main optimization goal, and a cost optimization dead zone is designed to take into account the overall SOC.

[0104] Specifically, for all energy storage units in the high-SOC state interval and low-SOC state interval, power is allocated with the best overall SOC of multiple energy storage power stations as the main optimization goal, and an SOC optimization dead zone is designed to take into account the economic benefits of frequency modulation; first, a mathematical model needs to be established to reflect the overall SOC of multiple energy storage power stations. During the normal operation of the regional power grid, each charge and discharge of the energy storage power station will change the SOC values of some or all of the internal energy storage units. When the scheduling period ΔT is fixed, the change in the SOC of the energy storage unit is mainly determined by the power supply rather than the output power, and the power supply is calculated by the following formula:

[0105]

[0106] Among them, P source,i,j (t) is the power supply of the energy storage unit j inside the energy storage power station i at the current moment, and α cd (t) is the charge and discharge flag at the current moment, which is determined by the positive and negative of the regional power grid command. When the command is negative, the value of α cd (t) is -1. When the command is positive, the value of α cd (t) is 1. When the command is 0, the value of α cd (t) is 0.

[0107] The change in SOC is calculated by the following formula:

[0108]

[0109] Among them, E N,i,j is the rated capacity of the energy storage unit j inside the energy storage power station i.

[0110] Establish a basic objective function Z1 to represent the overall SOC of multiple energy storage power stations:

[0111]

[0112] Among them, S i,j (t) is the SOC value of this energy storage unit at the current moment, and S perfect,i is the ideal SOC value of energy storage power station i. In order to make the charging and discharging capabilities of the energy storage power station as close as possible, the ideal SOC value should be calculated according to the charge and discharge efficiencies of different energy storage power stations:

[0113] S high,i - S perfect,i = (S perfect,i - S low,i )·η i 2

[0114] Establish a mathematical model to reflect the economic benefits of frequency modulation. Here, the total frequency modulation cost is simplified to the sum of the capacity investment cost, energy loss cost, and cycle life attenuation cost, and is calculated by the following formula:

[0115]

[0116]

[0117]

[0118]

[0119] Among them, are respectively the capacity investment cost, energy loss cost, cycle life attenuation cost, and total cost of energy storage power station i participating in frequency modulation at the current moment. c cap,i , E N,i are the unit capacity cost and rated capacity of energy storage power station i, r is the discount rate, T float,i is the floating charge life of energy storage power station i, c e is the on-grid electricity price, k p is a constant related to the battery life, c milinv,i , P N,i are respectively the unit power cost and rated power of energy storage power station i, N 0,i is the equivalent cycle number of energy storage power station i, P source,i (t), P output,i (t) are respectively the power supply power and output power of energy storage power station i at the current moment.

[0120] Establish a basic objective function Z2 to represent the economic benefits of multiple energy storage power stations participating in frequency modulation:

[0121]

[0122] Combine two basic objective functions into a new single-objective function according to the following formula:

[0123] Z = α z,soc ·Z1 + α z,cost ·Z2

[0124] where: α z,soc is the SOC weight factor, and α z,cost is the economic benefit weight factor. By changing the values of the two weight factors, the priority of each energy storage unit participating in power output during the power distribution process can be changed.

[0125] Specifically, for all energy storage units in the high state of charge (SOC) interval and the low SOC interval, it is necessary to allocate power with the overall best SOC of the multi-energy storage power station as the main optimization goal. At the same time, design a SOC optimization dead zone and take into account the economic benefits of frequency modulation. Therefore, add the following constraints:

[0126]

[0127] where: Z esm,2 is the estimated value of Z2, and Z esm,1 is the estimated value of Z1. The estimation method is as follows: First, assume that all energy storage units bear power according to the size of the rated power, that is, power is equally distributed. Then calculate Z1 and Z2 under this power distribution scheme, so as to obtain two estimated values. D in the above formula is the proportionality coefficient, representing the difference in the degree of emphasis on the two basic objectives. When allocating power for the high SOC interval and the low SOC interval, the value of D is much greater than 1.

[0128] Specifically, for all energy storage units in the low SOC transition interval and the high SOC transition interval, apply the cost-SOC sorting model to allocate power. The process is as Figure 3 shown. First, sort in ascending order according to the size of SOC, and then determine the energy storage unit with the smallest SOC and its corresponding charging interval. The minimum value of the charging interval is the minimum SOC value S1, and the maximum value S2 is obtained according to the following formula:

[0129]

[0130] where, P N,1 (t), η1, E N,1 are the rated power, charging efficiency, and rated capacity corresponding to the energy storage unit with the smallest SOC respectively. The energy storage units within the charging interval are all the energy storage units in the multi-energy storage power station with SOC values between S1 and S2. Define P sumis the maximum power in the charging interval. Compare this value with the charging instruction. If the charging instruction is greater, the smallest energy storage unit charges at its rated power, and this energy storage unit no longer participates in subsequent allocation. After subtracting the rated power of this energy storage unit from the charging instruction, a new charging instruction is obtained, and the energy storage units are sorted in ascending order according to the size of the SOC again. Cycle according to the above logic until P sum is greater than the value of the charging instruction. When the sum of the rated powers is greater than the value of the charging instruction, calculate the product of the SOC and the estimated cost of the energy storage units in the interval, and then sort them in ascending order to determine the priority. The energy storage units in the charging interval are charged in turn according to the priority. For the energy storage unit with a higher priority, if the output of the rated power still cannot fully meet the charging instruction, then this energy storage unit outputs at its rated power. The cost of each energy storage unit in the charging interval is estimated according to the following formula:

[0131]

[0132] where c e is the on-grid electricity price, c milinv,i , P N,i , E N,i , N 0,i are the unit power cost, rated power, rated capacity, and equivalent cycle times of the i-th energy storage power station respectively.

[0133] Similarly, power distribution can be carried out for the high battery state transition interval under the charging condition, the low battery state transition interval under the discharging condition, and the high battery state transition interval under the discharging condition.

[0134] For all energy storage units in the equilibrium state interval, the power is allocated with the best economic benefit of multiple energy storage power stations participating in frequency modulation as the main optimization goal, and at the same time, a cost optimization dead zone is designed to take into account the overall SOC.

[0135] The formula of the basic objective function is the same as above, but the constraint relationship between the two weight factors needs to be changed. For all energy storage units in the equilibrium state interval, the power needs to be allocated with the best economic benefit of multiple energy storage power stations participating in frequency modulation as the main optimization goal, and at the same time, a cost optimization dead zone is designed to take into account the overall SOC. Therefore, the value of the proportionality coefficient D is much less than 1.

[0136] Finally, considering the actual meaning of each physical quantity, the following constraints need to be satisfied while executing the optimization algorithm:

[0137] S min ≤S i,j (t)≤S max

[0138] 0≤P output,i,j (t)≤P N,i,j

[0139] S i,j S(t) = i,j S(t - 1)+ΔS i,j (t)

[0140]

[0141]

[0142] The embodiment of S3 realizes the coordinated operation between different energy storage power stations, and on the premise of ensuring the relatively healthy SOC, the frequency regulation cost of the energy storage power station is reduced as much as possible.

[0143] The feasibility of the multi - energy - storage secondary frequency regulation power distribution method of this application is tested on the experimental platform. The basic parameters of the energy storage power station are shown in Table 1.

[0144] Table 1 Basic parameters of the energy storage power station

[0145]

[0146] Figure 4 It is the simulation result diagram of the output of the multi - energy - storage power station. It can be seen that for most of the time, the total output of the energy storage power station can follow the AGC instruction to complete the secondary frequency regulation task.

[0147] Figure 5 It is the simulation result diagram of the number of multi - state intervals according to the example of the present invention. It can be seen that as the charge - discharge process progresses, the number of energy storage units in each state interval is constantly changing. The number of energy storage units in the balanced interval reaches the maximum near 89 minutes. At this time, the two - way output ability of the energy storage power station is the strongest.

[0148] Figure 6 It is the simulation result diagram of the output of the energy storage power station with different battery types according to the example of the present invention. The output of different energy storage power stations is affected not only by their own operating conditions (SOC of energy storage units, parameters of energy storage power stations), but also by the AGC instruction. Since the SOC of the energy storage units inside Power Station 3 is relatively high, Power Station 3 hardly participates in charging in the initial stage. Since the SOC of the energy storage units inside Power Station 4 is relatively low, Power Station 4 hardly participates in discharging in the initial stage. When the simulation reaches 60 minutes, the power demand of the regional power grid suddenly increases. Therefore, all the energy storage power stations after 60 minutes are in the discharging state, and the overall SOC value continuously decreases to meet the requirements of the AGC instruction of the regional power grid.

[0149] Corresponding to the embodiment of the foregoing multi - energy - storage secondary frequency regulation power distribution method, this application also provides an embodiment of a multi - energy - storage secondary frequency regulation power distribution device.

[0150] Figure 7It is a block diagram of a multi-energy storage secondary frequency modulation power distribution device shown according to an exemplary embodiment. Referring to Figure 7 , the device includes:

[0151] The SOC interval division module 1 is used to calculate six corresponding SOC thresholds for each energy storage power station based on the principle of balancing the bidirectional output capacity of the energy storage power station, where the six SOC thresholds are the minimum value, the charging transition value, the charging equilibrium value, the discharging equilibrium value, the discharging transition value, and the maximum value. Among them, the energy storage units with SOC values between the minimum value and the charging transition value form the low-power SOC interval, the energy storage units with SOC values between the charging transition value and the charging equilibrium value form the low-power transition SOC interval, the energy storage units with SOC values between the charging equilibrium value and the discharging equilibrium value form the equilibrium SOC interval, the energy storage units with SOC values between the discharging equilibrium value and the discharging transition value form the high-power transition SOC interval, and the energy storage units with SOC values between the discharging transition value and the maximum value form the high-power SOC interval. Then, calculate the charging and discharging power that all energy storage units in the five SOC intervals can jointly bear;

[0152] The SOC interval power preliminary distribution module 2 is used to determine the charging and discharging priorities of the five SOC intervals at the current moment and the SOC interval that uniquely needs to apply the optimization algorithm to distribute power according to the command requirements of the regional power grid at a certain moment and in combination with the charging and discharging capabilities of different SOC intervals. For the other four SOC intervals that do not require the application of the algorithm to distribute power, if the charging and discharging priority of this SOC interval is higher than the SOC interval that requires the application of the optimization algorithm to distribute power, then all energy storage units in this SOC interval output the rated power. If the charging and discharging priority of this interval is lower than the SOC interval that requires the application of the optimization algorithm to distribute power, then the power output by all energy storage units in this interval is 0;

[0153] The SOC interval power distribution optimization algorithm module 3 is used to select different power distribution algorithms according to different SOC intervals for the SOC interval that needs to apply the optimization algorithm to distribute power at the current moment. Specifically, it includes: 1) For all energy storage units in the high-power SOC interval and the low-power SOC interval, distribute power with the main optimization goal of the best overall SOC of the multi-energy storage power station, and at the same time design the SOC optimization dead zone to take into account the economic benefits of frequency modulation; 2) For all energy storage units in the low-power transition SOC interval and the high-power transition SOC interval, apply the cost-SOC sorting model to distribute power; 3) For all energy storage units in the equilibrium SOC interval, distribute power with the main optimization goal of the best economic benefits of the multi-energy storage power station participating in frequency modulation, and at the same time design the cost optimization dead zone to take into account the overall SOC.

[0154] Regarding the device in the above embodiments, the specific manner in which each module performs operations has been described in detail in the embodiments related to the method, and will not be elaborated here.

[0155] For the device embodiments, since they basically correspond to the method embodiments, the relevant parts can be referred to the descriptions in the method embodiments. The device embodiments described above are only illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this application. Those of ordinary skill in the art can understand and implement it without creative efforts.

[0156] Correspondingly, this application also provides an electronic device, including: one or more processors; a memory for storing one or more programs; when the one or more programs are executed by the one or more processors, the one or more processors implement the multi-energy storage secondary frequency modulation power distribution method as described above.

[0157] Correspondingly, this application also provides a computer-readable storage medium, on which computer instructions are stored, and when the instructions are executed by a processor, the multi-energy storage secondary frequency modulation power distribution method as described above is implemented.

[0158] Those skilled in the art will readily think of other embodiments of this application after considering the specification and practicing the content disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application, which follow the general principles of this application and include common general knowledge or conventional technical means in the technical field not disclosed in this application. The specification and embodiments are only regarded as exemplary, and the true scope and spirit of this application are pointed out by the claims.

[0159] It should be understood that this application is not limited to the exact structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is only limited by the appended claims.

Claims

1. A multi-energy storage secondary frequency regulation power distribution method, characterized in that Including: S1: Based on the principle of balancing the two-way output capacity of the energy storage power station, calculate the corresponding six SOC thresholds for each energy storage power station according to its charge-discharge efficiency. The six SOC thresholds are the minimum value, the charging transition value, the charging equilibrium value, the discharging equilibrium value, the discharging transition value, and the maximum value. Among them, the energy storage units with SOC values between the minimum value and the charging transition value form the low-power SOC interval, the energy storage units with SOC values between the charging transition value and the charging equilibrium value form the low-power transition SOC interval, the energy storage units with SOC values between the charging equilibrium value and the discharging equilibrium value form the equilibrium SOC interval, the energy storage units with SOC values between the discharging equilibrium value and the discharging transition value form the high-power transition SOC interval, and the energy storage units with SOC values between the discharging transition value and the maximum value form the high-power SOC interval. Then calculate the charge-discharge power that all energy storage units in the five SOC intervals can jointly bear. S2: According to the command requirements of the regional power grid at a certain moment, combined with the charge-discharge capabilities of different SOC intervals, determine the charge-discharge priorities of the five SOC intervals at the current moment and the only SOC interval that needs to apply the optimization algorithm to allocate power. For the other four SOC intervals that do not need to apply the algorithm to allocate power, if the charge-discharge priority of this SOC interval is higher than that of the SOC interval that needs to apply the optimization algorithm to allocate power, then all energy storage units in this SOC interval output the rated power. If the charge-discharge priority of this interval is lower than that of the SOC interval that needs to apply the optimization algorithm to allocate power, then the output power of all energy storage units in this interval is 0. S3: For the SOC interval that needs to apply the optimization algorithm to allocate power at the current moment, select different power allocation algorithms according to different SOC intervals, specifically including: 1) For all energy storage units in the high-power SOC interval and the low-power SOC interval, allocate power with the main optimization goal of the best overall SOC of multiple energy storage power stations, and at the same time design the SOC optimization dead zone to take into account the economic benefits of frequency modulation; 2) For all energy storage units in the low-power transition SOC interval and the high-power transition SOC interval, apply the cost-SOC sorting model to allocate power; 3) For all energy storage units in the equilibrium SOC interval, allocate power with the main optimization goal of the best economic benefits of multiple energy storage power stations participating in frequency modulation, and at the same time design the cost optimization dead zone to take into account the overall SOC.

2. The multi-energy storage secondary frequency modulation power distribution method according to claim 1, wherein In S1, calculating the corresponding six SOC thresholds according to the charge-discharge efficiency of each energy storage power station includes: Considering that the same-sized charging command and discharging command have different degrees of change on the SOC of the energy storage unit, there is the following constraint relationship between the six threshold variables: Among them: S min,i , S low,i , S perfect,c,i , S perfect,d,i , S high,i , S max,i are respectively the minimum value, charging transition value, charging balance value, discharging balance value, discharging transition value, and maximum value of the SOC of the energy storage unit inside the energy storage power station i, and η i is the charge-discharge efficiency of the energy storage power station i; Define S flag The matrix is used to describe the SOC intervals where all energy storage units are located: Where: S flag,i,j is a variable representing the state interval of the energy storage unit j inside the energy storage power station i, which are, in sequence from 1 to 5, the low battery SOC interval, the low battery transition SOC interval, the balanced SOC interval, the high battery transition SOC interval, and the high battery SOC interval.

3. The multi-energy storage secondary frequency modulation power distribution method according to claim 1, characterized in that In S3, for all energy storage units in the high-power SOC interval and the low-power SOC interval, allocate power with the main optimization goal of the best overall SOC of multiple energy storage power stations, and at the same time design the SOC optimization dead zone to take into account the economic benefits of frequency modulation, including: Define two basic objective functions according to the following formulas: Where: S i,j (t) is the SOC value of the energy storage unit at the current moment, S perfect,i is the ideal SOC value of energy storage power station i, is the total frequency regulation cost of energy storage power station i at the current moment, Z1 is the basic objective function representing the overall SOC of multiple energy storage power stations, and Z2 is the basic objective function representing the economic benefits of frequency regulation; Synthesize the two basic objective functions into a new single objective function according to the following formulas: Z = α z,soc ·Z1 + α z,cost ·Z2 Where: α z,soc is the SOC weight factor, and α z,cos t is the economic benefit weight factor. By changing the values of the two weight factors, the priority of each energy storage unit participating in the output during the power distribution process can be changed; Add the following constraints to reduce the numerical difference between the two objective functions: Where: Z esm,2 is the estimated value of Z2, and Z esm,1 is the estimated value of Z1.

4. The multi-energy storage secondary frequency modulation power distribution method according to claim 3, wherein The estimation method of the estimated value is as follows: First, it is assumed that all energy storage units bear power according to their rated power, that is, the power is equally proportionally distributed. Then, Z1 and Z2 under this power distribution scheme are calculated to obtain two estimated values. D in the above formula is a proportionality coefficient, representing the difference in the degree of emphasis on the two basic objectives. When distributing power for the high-SOC interval and the low-SOC interval, the value of D is much greater than 1.

5. The multi-energy storage secondary frequency modulation power distribution method according to claim 1, wherein For all energy storage units in the low-SOC transition interval and the high-SOC transition interval, apply the cost-SOC sorting model to distribute power, including: 1) Arrange them according to the size of SOC, and then determine the energy storage unit with the minimum SOC and its corresponding charging interval. The minimum value of the charging interval is the minimum SOC value S1, and the maximum value S2 is obtained according to the following formula: Among them, P N,1 (t), η1, E N,1 are respectively the rated power, charging efficiency and rated capacity corresponding to the energy storage unit with the minimum SOC; the energy storage units within the charging interval are all the energy storage units in the multi-energy storage power station with the SOC value between S1 and S2; 2) Compare P sum with the magnitude of the charging instruction. P sum is the sum of the rated powers of all energy storage units in the charging interval. If the charging instruction is larger, the smallest energy storage unit charges at its rated power, and this energy storage unit no longer participates in subsequent allocation. After subtracting the rated power of this energy storage unit from the charging instruction, a new charging instruction is obtained, and the energy storage units are sorted in ascending order according to the size of the SOC again. The above logic is looped until P sum is greater than the value of the charging instruction; 3) When the sum of the rated powers is greater than the charging command value, calculate the product of the SOC and the estimated cost of the energy storage units in the interval, and then sort them in ascending order to determine the priority. The energy storage units in the charging interval are charged in turn according to the priority. For the energy storage unit with a higher priority, if the output of the rated power still cannot fully meet the charging command, then this energy storage unit outputs power at the rated power. Among them, the cost of each energy storage unit in the charging interval is estimated according to the following formula: Among them, c e is the on-grid electricity price, c milinv,i , P N,i , E N,i , N 0,i are respectively the unit power cost, rated power, rated capacity and equivalent cycle number of energy storage power station i; Similarly, power distribution is carried out for the high-SOC transition interval under the charging condition, the low-SOC transition interval under the discharging condition, and the high-SOC transition interval under the discharging condition.

6. The multi-energy storage secondary frequency modulation power distribution method according to claim 1, characterized in that, In S3, for all energy storage units in the balanced SOC interval, the main optimization objective is to best distribute power for the economic benefits of multiple energy storage power stations participating in frequency modulation. At the same time, a cost optimization dead zone is designed to take into account the overall SOC, including: Define two basic objective functions according to the following formula: Where: S i,j (t) is the SOC value of the energy storage unit at the current moment, S perfect,i is the ideal SOC value of energy storage power station i, is the total frequency regulation cost of energy storage power station i at the current moment, Z1 is the basic objective function representing the overall SOC of multiple energy storage power stations, and Z2 is the basic objective function representing the economic benefits of frequency regulation; Combine the two basic objective functions into a new single objective function according to the following formula: Z = α z,soc ·Z1 + α z,cost ·Z2 Where: α z,soc is the SOC weight factor, and α z,cos t is the economic benefit weight factor. By changing the values of the two weight factors, the priority of each energy storage unit participating in the output during the power distribution process can be changed; Add the following constraints to reduce the numerical difference between the two objective functions: Where: Z esm,2 is the estimated value of Z2, and Z esm,1 is the estimated value of Z1.

7. The multi-energy storage secondary frequency modulation power distribution method according to claim 6, characterized in that, The estimation method of the estimated value is as follows: First, it is assumed that all energy storage units bear power according to their rated power, that is, the power is equally proportionally distributed. Then, Z1 and Z2 under this power distribution scheme are calculated to obtain two estimated values. D in the above formula is a proportionality coefficient, representing the difference in the degree of emphasis on the two basic objectives. When distributing power for the balanced SOC interval, the value of D is much less than 1.

8. A multi-energy storage secondary frequency regulation power distribution device, characterized in that, Including: The SOC interval division module is used to calculate six corresponding SOC thresholds for each energy storage power station based on the principle of balancing the two-way output capacity of the energy storage power station, where the six SOC thresholds are the minimum value, the charging transition value, the charging equilibrium value, the discharging equilibrium value, the discharging transition value, and the maximum value. Among them, the energy storage units with SOC values between the minimum value and the charging transition value constitute the low-power SOC interval, the energy storage units with SOC values between the charging transition value and the charging equilibrium value constitute the low-power transition SOC interval, the energy storage units with SOC values between the charging equilibrium value and the discharging equilibrium value constitute the equilibrium SOC interval, the energy storage units with SOC values between the discharging equilibrium value and the discharging transition value constitute the high-power transition SOC interval, and the energy storage units with SOC values between the discharging transition value and the maximum value constitute the high-power SOC interval. Then, calculate the charging and discharging power that all energy storage units in the five SOC intervals can jointly undertake; The SOC interval power preliminary distribution module is used to determine the charging and discharging priorities of the five SOC intervals at the current moment and the only SOC interval that needs to apply the optimization algorithm to distribute power according to the command requirements of the regional power grid at a certain moment and in combination with the charging and discharging capabilities of different SOC intervals. For the other four SOC intervals that do not need to apply the algorithm to distribute power, if the charging and discharging priority of this SOC interval is higher than that of the SOC interval that needs to apply the optimization algorithm to distribute power, then all energy storage units in this SOC interval output the rated power. If the charging and discharging priority of this interval is lower than that of the SOC interval that needs to apply the optimization algorithm to distribute power, then the power output by all energy storage units in this interval is 0; The SOC interval power distribution optimization algorithm module is used to select different power distribution algorithms according to different SOC intervals for the SOC interval that needs to apply the optimization algorithm to distribute power at the current moment. Specifically, it includes: 1) For all energy storage units in the high-power SOC interval and the low-power SOC interval, distribute power with the main optimization goal of the best overall SOC of multiple energy storage power stations, and at the same time design a SOC optimization dead zone to take into account the economic benefits of frequency modulation; 2) For all energy storage units in the low-power transition SOC interval and the high-power transition SOC interval, apply the cost-SOC sorting model to distribute power; 3) For all energy storage units in the equilibrium SOC interval, distribute power with the main optimization goal of the best economic benefits of multiple energy storage power stations participating in frequency modulation, and at the same time design a cost optimization dead zone to take into account the overall SOC.

9. An electronic device, characterized in that, Including: One or more processors; A memory for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method according to any one of claims 1-7.

10. A computer-readable storage medium having computer instructions stored thereon, wherein, When the instruction is executed by the processor, it implements the steps of the method according to any one of claims 1-7.

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