Energy storage agc power distribution control method considering soc operation constraint and related device

Abstract

The application discloses a method for energy storage AGC power distribution control considering SOC operation constraints and related devices, relates to the technical field of power grid energy storage scheduling, and responds to a power grid scheduling instruction to acquire state information of each energy storage unit and calculate a charging and discharging power available margin; a multi-objective comprehensive cost function is constructed with AGC tracking accuracy, SOC balance, battery life loss and power smoothing as targets, and equivalent SOC operation upper and lower limits of each energy storage unit are adjusted in real time according to the comprehensive cost value; on this basis, initial distribution power instruction of each energy storage unit is calculated according to the AGC adjustment direction and the adjusted equivalent SOC operation upper and lower limits, and closed-loop error correction, SOC protection coefficient correction and safety limit amplitude verification are sequentially performed, the over-limit instruction is limited and amplitude, and the difference is secondarily distributed and then issued and executed. The application unifies and coordinates multiple optimization targets through the multi-objective cost function, improves the effectiveness of energy storage power distribution, and guarantees the safety and stability of power grid operation.

Description

Technical Field

[0001] This invention relates to the field of power grid energy storage dispatching technology, and in particular to an energy storage AGC power allocation control method and related devices that consider SOC operation constraints. Background Technology

[0002] With the continuous increase in installed capacity of new energy sources, power system frequency regulation faces greater uncertainty and faster response requirements. Wind and solar power output is significantly affected by weather conditions, exhibiting randomness, intermittency, and short-term fluctuations. Traditional thermal power units, relying on mechanical inertia and speed control systems for automatic power generation control, often suffer from slow response speeds, limited ramp-up capabilities, insufficient regulation accuracy, and increased equipment wear due to frequent load changes. Electrochemical energy storage, with its millisecond-level response speed, bidirectional power regulation capability, and high control accuracy, can quickly compensate for regional control deviations in AGC frequency regulation, improving grid frequency stability and regulation performance. Therefore, incorporating energy storage power stations into the AGC control system has become an important technical path to enhance the frequency regulation capability of power systems with a high proportion of new energy sources.

[0003] When energy storage participates in AGC (Automatic Generation Control) management, its operating state is constrained by a variety of internal factors. The battery's state of charge (SOC) determines the available energy space, the charging and discharging power limits and the converter capacity constitute the output boundary, and frequent power adjustments accelerate battery life degradation. These factors are interconnected and dynamically change, jointly affecting the continuous frequency regulation capability of the energy storage unit. If these constraints are ignored, the energy storage unit may exceed its safe operating range after continuous adjustments, resulting in its inability to respond to dispatch demands in subsequent periods. If power is allocated according to fixed rules, it is difficult to adapt to the real-time differences and dynamic changes in the states of each unit. To address this, researchers have proposed methods to correct the allocated power based on the unit's state, such as adjusting the output ratio based on the SOC or setting a state warning interval for power limitation. However, such methods distribute different correction logics across independent stages. One stage corrects the power based on the energy state, another stage corrects the power based on the output boundary, and yet another stage corrects the power based on the adjustment change. Each stage calculates independently and then sums the corrections for output. This architecture leads to a lack of unified coordination mechanisms among the various correction stages. When one stage requires increasing the output of a unit, another stage might require decreasing its output. These adjustments, when combined, cancel each other out or interfere with each other. The system cannot determine the most critical optimization direction at the overall level, and the effects of each stage's corrections weaken each other during the superposition process, making it difficult to optimize the overall performance of the energy storage cluster. Furthermore, the aforementioned correction rules are mostly fixed designs, lacking awareness and adaptive capabilities regarding the overall system operating status. When operating conditions change, they cannot proactively adjust the correction direction, limiting the energy storage system's ability to adapt to complex operating conditions. Summary of the Invention

[0004] This invention provides a power allocation control method and related device for energy storage AGC that takes into account SOC operating constraints, solving the technical problem of how to improve the effectiveness of power allocation and ensure the safe and stable operation of the power grid.

[0005] The first aspect of this invention provides a power allocation control method for energy storage AGC considering SOC operating constraints, comprising:

[0006] In response to the grid dispatching instructions of the target power grid, obtain the energy storage unit status information of each energy storage unit within the target power grid;

[0007] The available charge / discharge power margin is calculated using the energy storage unit status information;

[0008] Construct a multi-objective comprehensive cost function, and adjust the upper and lower limits of the equivalent SOC operation of each energy storage unit according to the comprehensive cost value of the multi-objective comprehensive cost function;

[0009] The AGC adjustment direction is determined according to the power grid dispatch command, and the initial power allocation command of each energy storage unit is calculated using the adjusted equivalent SOC operating upper and lower limits.

[0010] Error tracking and correction are performed using all the initial power allocation commands to obtain the corrected energy storage power command;

[0011] The target power allocation command is calculated using the energy storage unit status information and the corrected energy storage power command, and the power allocation is performed in combination with the safe limit range formed by the available charge and discharge power margin.

[0012] Optionally, the step of constructing a multi-objective comprehensive cost function and adjusting the upper and lower limits of the equivalent SOC operation of each energy storage unit according to the comprehensive cost value of the multi-objective comprehensive cost function includes:

[0013] With AGC tracking accuracy, SOC equalization, battery life loss and power smoothing as objectives, a multi-objective comprehensive cost function for the target power grid is constructed.

[0014] The energy storage unit's state information is input into the multi-objective comprehensive cost function for solution, yielding the comprehensive cost value.

[0015] The upper and lower limits of the equivalent SOC operation within the energy storage unit's state information are adjusted based on the comprehensive cost value.

[0016] Optionally, the step of calculating the initial power allocation command for each energy storage unit based on the AGC adjustment direction determined by the grid dispatch command and using the adjusted equivalent SOC operating upper and lower limits includes:

[0017] The AGC adjustment direction is determined according to the power grid dispatching instruction, and the upper and lower limits of the adjusted equivalent SOC and the state of charge are used to calculate the charging and discharging condition weights of each energy storage unit.

[0018] The initial power allocation command for each energy storage unit is obtained by multiplying the power grid dispatch command with the charging and discharging condition weights.

[0019] Optionally, the step of using all the initial power allocation commands for error tracking and correction to obtain a corrected energy storage power command includes:

[0020] The total initial charge / discharge power command is calculated using all of the aforementioned initial power allocation commands;

[0021] The difference between the power grid dispatch command and the total initial charge / discharge power command is calculated to obtain the AGC command tracking error.

[0022] The AGC command is used to track the error and perform PI control to obtain the error correction power command;

[0023] The initial power allocation command and the error correction power command are respectively used to perform a summation operation to obtain the corrected energy storage power command.

[0024] Optionally, the step of calculating the target power allocation command using the energy storage unit status information and the corrected energy storage power command, and then allocating power within a safe limiting range formed by the available charge and discharge power margin, includes:

[0025] The SOC over-limit risk factor of each energy storage unit is calculated using the energy storage unit status information;

[0026] The SOC protection factor of each energy storage unit is calculated using the SOC over-limit risk factor.

[0027] The target power allocation command for each energy storage unit is obtained by multiplying the SOC protection coefficient with the modified energy storage power command.

[0028] Determine whether each of the target power allocation commands is within the safe limit range formed by the available charging and discharging power margin;

[0029] If so, the target power allocation commands are sent to the corresponding energy storage unit converters and executed.

[0030] If not, the target power allocation command for the corresponding energy storage unit will be limited to the boundary value of the safe limit range, and the difference power command generated by the limit will be redistributed and then sent out for execution.

[0031] Optionally, it also includes:

[0032] Construct the SOC dynamic update equations for each of the energy storage units and set SOC safe operating range constraints;

[0033] Under the constraints of the SOC safe operating range, the actual charging and discharging power output by the energy storage unit after the issuance of each target power allocation command is input into the corresponding SOC dynamic update equation for solving, and the corresponding new state of charge is obtained.

[0034] The new state of charge is used to update the energy storage unit state information to obtain new energy storage unit state information;

[0035] Based on the new energy storage unit status information and the new power grid dispatch instructions, the process jumps to execute the step of calculating the available charge and discharge power margin using the energy storage unit status information.

[0036] A second aspect of the present invention provides an energy storage AGC power distribution control system that considers SOC operating constraints, comprising:

[0037] The data acquisition module is used to respond to the grid dispatching instructions of the target power grid and acquire the energy storage unit status information of each energy storage unit in the target power grid;

[0038] The margin calculation module is used to calculate the available margin of charging and discharging power using the energy storage unit's state information;

[0039] The boundary adjustment module is used to construct a multi-objective comprehensive cost function and adjust the upper and lower limits of the equivalent SOC operation of each energy storage unit according to the comprehensive cost value of the multi-objective comprehensive cost function.

[0040] The weight allocation module is used to calculate the initial allocation power command for each energy storage unit based on the AGC adjustment direction determined by the power grid dispatch command and using the adjusted equivalent SOC operating upper and lower limits.

[0041] An error correction module is used to perform error tracking and correction using all the initial power allocation commands to obtain a corrected energy storage power command.

[0042] The safety verification module is used to calculate the target power allocation command using the energy storage unit status information and the corrected energy storage power command, and to perform power allocation in combination with the safety limit range formed by the available charge and discharge power margin.

[0043] A third aspect of the present invention provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor performs the steps of the energy storage AGC power allocation control method considering SOC operating constraints as described above.

[0044] The fourth aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed, it implements the energy storage AGC power allocation control method considering SOC operating constraints as described above.

[0045] The fifth aspect of the present invention provides a computer program product, the computer program product comprising a computer program stored on a non-transitory computer-readable storage medium, the computer program comprising program instructions, wherein, when the program instructions are executed by a computer, the computer performs the energy storage AGC power allocation control method considering SOC operating constraints as described above.

[0046] As can be seen from the above technical solutions, the present invention has the following advantages:

[0047] This invention provides a power allocation control method and related device for energy storage AGC considering SOC (State of Charge) operating constraints. First, by acquiring the state information of energy storage units and calculating the available margin of charging and discharging power, the safe operating boundary of each energy storage unit is determined. Second, by constructing a multi-objective comprehensive cost function, multiple factors such as the tracking status of grid dispatch commands, the energy state of each energy storage unit, and lifetime loss are uniformly evaluated to generate a comprehensive cost value reflecting the overall system performance. This cost value is used to dynamically adjust the upper and lower limits of the equivalent SOC operating for each energy storage unit in power allocation, so that the energy state evaluation boundary of each unit involved in power allocation adaptively changes with the overall system situation. This embeds overall coordination information at the allocation decision stage, avoiding the problems of conflicting correction directions and mutually weakening effects caused by the superposition of independently corrected optimization objectives in traditional methods. Furthermore, this invention... This invention calculates the initial power allocation command for each energy storage unit based on the AGC adjustment direction determined by the grid dispatch command and the adjusted equivalent state of charge (SOC) operating limits. After error tracking and correction of all initial power allocation commands, a corrected energy storage power command is obtained, effectively eliminating the deviation between the initial allocation command and the grid dispatch command, and improving the accuracy of power allocation response to dispatch commands. Finally, this invention combines the corrected energy storage power command with the energy storage unit status information to calculate the target power allocation command, and performs power allocation within a safe limiting range defined by the available charging and discharging power margin. This ensures that the final power command issued to each energy storage unit converter is strictly within the safe adjustable range of each unit. Simultaneously, the differential power command generated by the limiting is redistributed, ensuring that each energy storage unit does not exit regulation due to command exceeding limits, and ensuring complete tracking of the total output to the grid dispatch command. This invention, while ensuring that each energy storage unit operates within a safe range, fundamentally addresses multiple requirements such as tracking accuracy, energy balance, lifespan maintenance, and safety constraints in the power allocation result, improving the effectiveness of energy storage power allocation and ensuring the safe and stable operation of the power grid. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 A flowchart illustrating the steps of an energy storage AGC power allocation control method considering SOC operating constraints, provided in an embodiment of the present invention;

[0050] Figure 2 This is a schematic diagram of the three-dimensional curved surface for AGC power allocation according to the present invention;

[0051] Figure 3 This is a schematic diagram illustrating the SOC variation curve results of each energy storage unit in this invention;

[0052] Figure 4 This is a schematic diagram illustrating the comparative analysis of the battery equivalent loss results of different methods in this invention.

[0053] Figure 5 This invention provides a structural block diagram of an energy storage AGC power allocation control system that considers SOC operating constraints.

[0054] Figure 6 This is a structural block diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0055] This invention provides a power allocation control method and related device for energy storage AGC that considers SOC operating constraints, which is used to solve the technical problem of how to improve the effectiveness of power allocation and ensure the safe and stable operation of the power grid.

[0056] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] Target power grid: refers to the regional power system equipped with an energy storage system and participating in frequency regulation by Automatic Generation Control (AGC), which is the control object of the method of this invention.

[0058] Grid dispatch instructions: These are automatic generation control (AGC) instructions generated by the grid dispatch master station based on regional control deviations and issued to energy storage power stations for adjusting power output. They include target adjustment power and adjustment direction information.

[0059] Energy storage unit: refers to a single energy storage device in the target power grid that participates in AGC regulation, including battery systems, power conversion systems (PCS) and their supporting battery management systems (BMS), as the basic unit of power distribution.

[0060] Energy storage unit status information: refers to the data set reflecting the current operating status of the energy storage unit, including at least the state of charge (SOC), charging and discharging power and rated capacity of each energy storage unit.

[0061] Available charge / discharge power margin: refers to the upper limit of additional charging or discharging power that the energy storage unit can safely undertake within the current control cycle, including the available discharge margin and the available charging margin, which is limited by the rated power of the energy storage converter and the state of charge boundary constraints.

[0062] Multi-objective comprehensive cost function: refers to a weighted summation evaluation function constructed with AGC tracking accuracy, SOC equalization, battery life loss and power smoothing as optimization objectives, used to uniformly characterize the overall operating performance of the energy storage cluster in each control cycle.

[0063] Comprehensive cost value: refers to the scalar value obtained by substituting the state information of energy storage units into the multi-objective comprehensive cost function. It is used to quantitatively evaluate the overall operating performance of the energy storage cluster at the current moment. The smaller the value, the better the overall performance.

[0064] Equivalent State of Charge (SOC) Operating Limits: These refer to the lower and upper limits of the actual state of charge (SOC) used by the energy storage unit when participating in power distribution calculations. The EMS dynamically adjusts these limits based on real-time feedback of the comprehensive cost value, adaptively shrinking or recovering within the absolute safe range of SOC allowed by the equipment. This is distinct from the fixed absolute safe boundary of SOC of the equipment.

[0065] AGC adjustment direction: refers to the power adjustment direction determined by the grid dispatch command, including the discharge direction (if the command is positive, the energy storage cluster as a whole increases the discharge power) and the charging direction (if the command is negative, the energy storage cluster as a whole increases the charging power).

[0066] Initial power allocation command: refers to the initial power allocation result of each energy storage unit obtained after multiplying the grid dispatch command with the charging and discharging condition weights. It is an intermediate calculated value without error correction and safety protection processing.

[0067] Corrected energy storage power command: refers to the power command obtained after PI closed-loop error tracking and correction of the initial allocated power command. It is an intermediate calculated value that has been compensated for tracking error but has not been processed by SOC safety protection.

[0068] Target power allocation command: refers to the power command of each energy storage unit after correction by the SOC protection coefficient multiplication. It is an intermediate calculated value that has passed SOC safety protection but has not yet undergone safety limit verification.

[0069] Safety limit range: refers to the allowable power range consisting of the available power margin for charging and discharging of each energy storage unit. Specifically, the lower limit is the negative value of the available charging margin and the upper limit is the positive value of the available discharging margin. It is used to perform safety verification on the target power allocation command.

[0070] Power allocation: refers to the process of proportionally dividing the grid dispatch command according to the charging and discharging conditions of each energy storage unit, and then, after error correction, safety protection and amplitude limiting verification, forming the final power command to be executed by each energy storage unit.

[0071] Please see Figure 1 , Figure 1 The flowchart illustrates the steps of an energy storage AGC power allocation control method considering SOC operating constraints, as provided in an embodiment of the present invention.

[0072] This invention provides a power allocation control method for energy storage AGC considering SOC operating constraints, comprising:

[0073] Step 101: Respond to the grid dispatching instructions of the target power grid and obtain the energy storage unit status information of each energy storage unit in the target power grid.

[0074] In this embodiment of the invention, the Energy Management System (EMS) of the energy storage power station maintains a real-time communication connection with the power grid dispatch master station through a preset communication interface, and receives power grid dispatch instructions issued by the master station. Specifically, the EMS interacts with the remote terminal unit (RTU) of the master station, receiving power grid dispatch instructions containing the target regulation power and regulation direction. The power grid dispatch instructions received by the EMS are generated by the master station based on the current regional control deviation. Regional control deviation is a key indicator for measuring the degree of power imbalance in a power grid region, and its calculation formula is as follows:

[0075] ;

[0076] In the formula, For the current control cycle Temporal regional control deviation; For the current control cycle The power deviation of the connecting line at any given time; This is the frequency deviation coefficient; For the current control cycle The system frequency deviation at any given time. The scheduling master station based on... The numerical values ​​and directions are used to generate corresponding power grid dispatch commands, which are then sent to the energy storage power station's EMS.

[0077] Simultaneously, the EMS communicates with the Battery Management System (BMS) and Power Conversion System (PCS) controllers of each energy storage unit via fieldbus or industrial Ethernet. The EMS periodically collects the energy storage unit status information of each unit according to a set sampling period (e.g., every 100 milliseconds or every 1 second). This status information includes at least the State of Charge (SOC), charging / discharging power, rated capacity, lower and upper equivalent SOC operating limits for each energy storage unit. The EMS then timestamps and formats the collected grid dispatch commands and energy storage unit status information before storing them in a local real-time database.

[0078] Step 102: Calculate the available margin of charge and discharge power using the energy storage unit status information.

[0079] In this embodiment of the invention, the EMS reads the energy storage unit status information of each energy storage unit from a local real-time database, including state of charge, charge / discharge power, rated capacity, lower limit of equivalent state of charge (SOC) operation, and upper limit of equivalent SOC operation. Combined with the rated power of the energy storage converter, charge / discharge efficiency, and control cycle of each energy storage unit pre-stored in the EMS configuration database, the EMS calculates the available charge / discharge power margin for each energy storage unit in the current control cycle. The available charge / discharge power margin includes the available discharge margin and the available charge margin.

[0080] For the For each energy storage unit, the discharge margin represents the maximum power available for discharge regulation within the current control cycle, and is calculated using the following formula:

[0081] ;

[0082] In the formula, For the first Each energy storage unit in the current control cycle The maximum power available for discharge regulation at any given time. For the first The rated power of the energy storage converter for each energy storage unit For the first Each energy storage unit in the current control cycle State of charge at time t, For the first The lower limit of the equivalent SOC operation of each energy storage unit For the first The rated capacity of each energy storage unit For the first The discharge efficiency of each energy storage unit To control the cycle.

[0083] Similarly, for the first For each energy storage unit, its charge margin represents the maximum power that the unit can use for charge regulation within the current control cycle, and is calculated using the following formula:

[0084] ;

[0085] In the formula, For the first Each energy storage unit in the current control cycle The maximum power available for charging regulation at any given time. For the first The rated power of the energy storage converter for each energy storage unit For the first The upper limit of the equivalent SOC operation of each energy storage unit For the first Each energy storage unit in the current control cycle State of charge at time t, For the first The rated capacity of each energy storage unit For the first The charging efficiency of each energy storage unit To control the cycle.

[0086] The EMS iterates through all energy storage units, calculates the discharge and charge margins of each unit, and stores the calculated margin data in a real-time database for subsequent steps. The rated power of the energy storage converter, the allowable lower and upper limits of SOC for each energy storage unit, the charge / discharge efficiency, and the control cycle are all predetermined by the equipment parameters and operating procedures of each energy storage unit and stored in the EMS configuration database.

[0087] Furthermore, the actual AGC regulation power undertaken by each energy storage unit should not exceed the corresponding available margin calculated above in the charging and discharging directions, i.e., satisfy the following constraints:

[0088] ;

[0089] In the formula, For the first Each energy storage unit in the current control cycle The maximum power available for charging regulation at any given time. For the first Each energy storage unit in the current control cycle The actual AGC regulation power at all times For the first Each energy storage unit in the current control cycle The maximum power available for discharge regulation at any given time. The interval described by this inequality is the safety limit interval formed by the available charge and discharge power margin, which is used to perform safety verification of the target power allocation command for each energy storage unit in subsequent steps.

[0090] Step 103: Construct a multi-objective comprehensive cost function, and adjust the upper and lower limits of the equivalent SOC operation of each energy storage unit according to the comprehensive cost value of the multi-objective comprehensive cost function.

[0091] Furthermore, step 103 may include the following sub-steps:

[0092] S11. Construct a multi-objective comprehensive cost function for the target power grid, with the goals of AGC tracking accuracy, SOC equalization, battery life loss and power smoothing.

[0093] SOC equilibrium: refers to one of the sub-objectives of the multi-objective comprehensive cost function. It achieves the overall energy state balance of the energy storage cluster by making the state of charge of each energy storage unit converge to the desired SOC reference value, thereby avoiding overcharging or over-discharging of some units.

[0094] In this embodiment of the invention, the EMS constructs a multi-objective comprehensive cost function with AGC tracking accuracy, SOC equalization, battery life loss, and power smoothing as optimization objectives. This function consists of a weighted sum of four sub-objective functions, each corresponding to one of the four optimization objectives mentioned above.

[0095] The sub-objective function used to describe the AGC tracking accuracy target, namely the AGC tracking error objective function, is expressed as follows:

[0096] ;

[0097] In the formula, For the current control cycle The objective function value of AGC tracking error at time t represents the square of the deviation between the grid dispatch command and the total AGC regulation power actually undertaken by all energy storage units. It is used to measure the overall tracking accuracy of the energy storage cluster to the grid dispatch command. For the current control cycle Power grid dispatch instructions at any time; This represents the total number of energy storage units. For the first Each energy storage unit in the current control cycle The actual AGC regulation power that is always being borne.

[0098] The sub-objective function used to describe the SOC equilibrium objective, i.e., the SOC equilibrium objective function, is expressed as follows:

[0099] ;

[0100] In the formula, For the current control cycle The SOC balance objective function value at time t represents the sum of squares of the deviations of the current state of charge of each energy storage unit from the expected SOC reference value, and is used to measure the overall energy balance level of the energy storage cluster. For the first Each energy storage unit in the current control cycle The state of charge at any given moment; The expected SOC reference value is preset by the system operating procedures.

[0101] The sub-objective function used to describe the battery life loss target, namely the energy storage cluster life loss objective function, is obtained by summing the equivalent life loss of each energy storage unit in the current control cycle. The expression for the equivalent life loss of a single energy storage unit in the current control cycle is:

[0102] ;

[0103] In the formula, For the first Each energy storage unit in the current control cycle Equivalent lifetime loss at any given moment; For the first The energy throughput loss coefficient of each energy storage unit reflects the degree of influence of charge and discharge energy on the battery cycle life. For the first Each energy storage unit in the current control cycle The actual AGC regulation power borne at any given time; To control the cycle; For the first The power ramp-up loss coefficient of each energy storage unit reflects the degree of influence of the power change rate on battery life. For the first Each energy storage unit in the current control cycle The change in power at any given moment relative to the previous control cycle.

[0104] The expression for the objective function of energy storage cluster lifetime loss is:

[0105] ;

[0106] In the formula, For the current control cycle The objective function value of the energy storage cluster lifetime loss at time t represents the sum of the equivalent lifetime loss of all energy storage units and is used to measure the overall lifetime degradation of the energy storage cluster.

[0107] The sub-objective function used to describe the power smoothing objective, namely the energy storage power smoothing objective function, is expressed as follows:

[0108] ;

[0109] In the formula, For the current control cycle The energy storage power smoothing objective function value at time t represents the sum of squares of the AGC regulation power changes actually undertaken by each energy storage unit in adjacent control cycles, and is used to measure the overall power fluctuation of the energy storage cluster. and The first Each energy storage unit in the current control cycle Time and previous control cycle The actual AGC regulation power that is always being borne.

[0110] Based on the above four sub-objective functions, the multi-objective integrated cost function expression constructed by EMS is as follows:

[0111] ;

[0112] In the formula, For the current control cycle The comprehensive cost value at any given moment is used to uniformly characterize the overall operational performance of the energy storage cluster at the current moment; These are the weight coefficients for the corresponding sub-objectives, pre-set by the system operating procedures according to actual operational needs, and ensuring that all weight coefficients are positive. This multi-objective comprehensive cost function unifies the four optimization objectives of different dimensions into the same evaluation framework. The EMS embeds this function into the control flow as the basis for subsequent adjustments to the upper and lower limits of the equivalent SOC.

[0113] S12. Input the energy storage unit state information into the multi-objective comprehensive cost function to solve for the comprehensive cost value.

[0114] In this embodiment of the invention, the EMS reads the energy storage unit status information of the current control cycle from the real-time database. The energy storage unit status information includes the state of charge of each energy storage unit, the actual AGC regulation power undertaken, and the actual power undertaken in the previous control cycle. The above data is substituted into the multi-objective comprehensive cost function constructed in step S11 for solution. Specifically, the EMS first calculates... , , , The values ​​of the four sub-objective functions in the current control cycle are then weighted and summed according to the preset weight coefficients corresponding to each sub-objective. The resulting weighted sum is the comprehensive cost of the current control cycle. The comprehensive value It is a scalar quantity that comprehensively reflects the overall operational performance of an energy storage cluster in four aspects: tracking accuracy, energy balance, lifetime loss, and power smoothing within the current control cycle. A smaller value indicates better overall system performance. A higher value indicates that the overall system performance deviates further from the optimal state. EMS will calculate the comprehensive cost value. and the comprehensive cost of the previous control cycle Stored in a real-time database.

[0115] S13. Adjust the upper and lower limits of the equivalent SOC operation in the energy storage unit status information according to the comprehensive cost value.

[0116] In this embodiment of the invention, the EMS reads the comprehensive cost of the current control cycle from the real-time database. and the comprehensive cost of the previous control cycle ,Will and A comparison is made, and based on the comparison results, the lower and upper limits of the equivalent State of Charge (SOC) within the energy storage unit's state information are dynamically adjusted. The specific adjustment method is as follows:

[0117] like This indicates that the overall operating performance of the energy storage cluster in the current control cycle has deteriorated compared to the previous control cycle. At this time, the EMS will raise the lower limit of the equivalent SOC of each energy storage unit by one adjustment step based on the safe lower limit of the SOC allowed by the equipment, and at the same time lower the upper limit of the equivalent SOC by the same or corresponding adjustment step based on the safe upper limit of the SOC allowed by the equipment, thereby tightening the effective range of SOC.

[0118] like This indicates that the overall operating performance of the energy storage cluster in the current control cycle has improved compared to the previous control cycle. At this time, the EMS will restore the equivalent SOC lower limit and equivalent SOC upper limit of each energy storage unit to the safe lower limit and safe upper limit of the SOC allowed by the equipment, respectively.

[0119] like This indicates that the overall operating performance of the energy storage cluster has not changed significantly, and the EMS maintains the current lower and upper limits of the equivalent SOC.

[0120] The above adjustment step size and the change in comprehensive cost value The values ​​exhibit a monotonically positive correlation: the greater the change in the comprehensive cost value, the greater the adjustment range of the upper and lower limits of the equivalent SOC; conversely, the smaller the change in the comprehensive cost value, the smaller the adjustment range. Under no circumstances will the lower limit of the equivalent SOC of each energy storage unit be lower than the absolute safe lower limit of the equipment's allowed SOC, and under no circumstances will the upper limit of the equivalent SOC be higher than the absolute safe upper limit of the equipment's allowed SOC, ensuring that the upper and lower limits of the equivalent SOC always remain within the safe operating range allowed by the equipment. The EMS updates the adjusted lower and upper limits of the equivalent SOC to the energy storage unit status information in the real-time database.

[0121] Step 104: Based on the AGC adjustment direction determined by the power grid dispatching instruction, and using the adjusted equivalent SOC operating upper and lower limits, calculate the initial power allocation instruction for each energy storage unit.

[0122] In this embodiment of the invention, the EMS reads power grid dispatch instructions from a real-time database. and the energy storage unit status information, including the state of charge of each energy storage unit. The equivalent SOC operating lower limit adjusted in step S13 Equivalent SOC operating limit And read the discharge margin of each energy storage unit calculated in step 102. and charging margin The charging and discharging operating weights of each energy storage unit are calculated based on the AGC adjustment direction determined by the power grid dispatching instructions, and then the initial power allocation instructions for each energy storage unit are calculated.

[0123] Furthermore, step 104 may include the following sub-steps:

[0124] S21. Based on the AGC adjustment direction determined by the power grid dispatching instructions, and using the adjusted equivalent SOC operating upper and lower limits, as well as the state of charge, calculate the charging and discharging condition weights of each energy storage unit.

[0125] Charge / discharge condition weight: refers to the power allocation ratio coefficient of each energy storage unit obtained by using the corresponding calculation formula according to different AGC adjustment directions, including the discharge allocation weight in the discharge direction and the charging allocation weight in the charging direction, and the sum of the weights of each energy storage unit is 1.

[0126] In this embodiment of the invention, the EMS first follows the power grid dispatch instructions. The sign of the value determines the direction of AGC adjustment in the current control cycle: when When this occurs, it indicates that the system needs to increase the overall discharge power of the energy storage cluster, meaning the AGC adjustment direction is the discharge direction; when When this occurs, it indicates that the system needs the entire energy storage cluster to increase its charging power (absorbed power), meaning the AGC adjustment direction is the charging direction; when When the time is 0, it indicates that the system has no adjustment requirements and no power allocation is needed.

[0127] After determining the AGC adjustment direction, the EMS selects the corresponding weight calculation formula according to the adjustment direction, and calculates the charge and discharge condition weights of each energy storage unit using the state of charge of each energy storage unit and the adjusted equivalent SOC operating upper and lower limits.

[0128] When the AGC adjustment direction is the discharge direction, the first The discharge allocation weight of each energy storage unit is calculated using the following formula:

[0129] ;

[0130] In the formula, For the first Each energy storage unit in the current control cycle Discharge allocation weights at specific times; For the first Each energy storage unit in the current control cycle The state of charge at any given moment; For the first The equivalent SOC lower limit of each energy storage unit after adjustment in step S13; For the first Each energy storage unit in the current control cycle Discharge margin at any given time; This represents the total number of energy storage units. The first The state of charge (SOC), adjusted equivalent state of charge (EOC) lower limit, and discharge margin of each energy storage unit are calculated. The denominator is the sum of the numerators of all energy storage units. This is used to normalize the weights so that the sum of the discharge allocation weights of all energy storage units is 1.

[0131] When the AGC adjustment direction is the charging direction, the first... The charging allocation weight of each energy storage unit is calculated using the following formula:

[0132] ;

[0133] In the formula, For the first Each energy storage unit in the current control cycle The charging allocation weight at any given moment; For the first The equivalent SOC operating limit of each energy storage unit after adjustment in step S13; For the first Each energy storage unit in the current control cycle The available charging margin at any given time; the denominator is the sum of the numerators of all energy storage units, used to normalize the weights.

[0134] The calculation logic for the above-mentioned discharge allocation weight and charging allocation weight is as follows: During discharge, energy storage units with higher state of charge and larger discharge margins receive a larger allocation weight, thus undertaking more discharge power; during charging, energy storage units with lower state of charge and larger charging margins receive a larger allocation weight, thus undertaking more charging power. Since the equivalent SOC operating limits have been dynamically adjusted based on the comprehensive cost value in step S13, when the overall system performance deteriorates, the equivalent SOC operating lower limit is raised and the equivalent SOC operating upper limit is lowered, resulting in… and The value is smaller under the same conditions compared to before adjustment, thus more significantly suppressing energy storage units whose SOC is already close to the boundary from continuing to adjust in that direction during weight calculation, realizing the SOC balance target at the weight allocation level. EMS stores the calculated charge and discharge condition weights of each energy storage unit in a real-time database.

[0135] S22. The initial power allocation command for each energy storage unit is obtained by multiplying the grid dispatch command with the charging and discharging condition weights.

[0136] In this embodiment of the invention, the EMS reads the grid dispatch command and the charging and discharging condition weights of each energy storage unit from the real-time database, and performs a multiplication operation between the grid dispatch command and the charging and discharging condition weights of each energy storage unit to obtain the initial power allocation command for each energy storage unit. Specifically, the following formula is used for calculation:

[0137] ;

[0138] In the formula, For the first Each energy storage unit in the current control cycle Initial power allocation command at time; For the first Each energy storage unit in the current control cycle The charge / discharge condition weights at any given time are selected from the discharge allocation weights or charge allocation weights calculated in step S21 based on the AGC adjustment direction of the current control cycle (when the adjustment direction is discharge, the weights are selected as follows). Adjust the direction to take during charging. ; For the current control cycle Power grid dispatch instructions at any time.

[0139] The physical meaning of this multiplication operation is: to proportionally split the grid dispatch command according to the charging and discharging condition weights of each energy storage unit, so that the initial power allocation command undertaken by each energy storage unit is proportional to its weight. The EMS stores the calculated initial power allocation command for each energy storage unit in a real-time database.

[0140] Step 105: Use all initial power allocation commands for error tracking and correction to obtain the corrected energy storage power command.

[0141] Total initial charge and discharge power command: refers to the sum of the initial power allocation commands of all energy storage units, which is used to perform difference calculation with the grid dispatch command to determine the tracking error.

[0142] AGC command tracking error: refers to the deviation between the grid dispatch command and the total power that the energy storage cluster can actually handle. It is obtained by calculating the difference between the grid dispatch command and the total initial charge and discharge power command.

[0143] PI control: refers to the proportional-integral control method, which is used to generate error correction power commands based on the tracking error of AGC instructions. The proportional element responds quickly to the current error, while the integral element eliminates historical accumulated errors to improve steady-state tracking accuracy.

[0144] Error-corrected power command: refers to the power correction amount of each energy storage unit output after the PI controller performs proportional-integral adjustment on the tracking error of the AGC command, which is used to compensate for the deviation between the initial power allocation command and the grid dispatch command.

[0145] Furthermore, step 105 may include the following sub-steps:

[0146] S31. Calculate the total initial charge and discharge power command using all initial power allocation commands.

[0147] In this embodiment of the invention, the EMS reads the initial power allocation instructions of each energy storage unit from the real-time database, and sums the initial power allocation instructions of all energy storage units to obtain the total initial power allocation instructions of the energy storage cluster. Specifically, the following formula is used for calculation:

[0148] ;

[0149] In the formula, For the current control cycle The total initial power allocation command for the energy storage cluster at any given time is the sum of the initial power allocation commands for all energy storage units. The EMS stores the calculated total initial power allocation command in a real-time database.

[0150] S32. The difference between the power grid dispatch command and the total initial charging and discharging power command is calculated to obtain the AGC command tracking error.

[0151] In this embodiment of the invention, the EMS reads the power grid dispatching command and the total initial power allocation command calculated in step S31 from the real-time database, and performs a difference calculation between the power grid dispatching command and the total initial power allocation command to obtain the AGC command tracking error for the current control cycle. Specifically, the following formula is used for calculation:

[0152] ;

[0153] In the formula, For the current control cycle The AGC command tracking error at any given time represents the deviation between the grid dispatch command and the initial total power allocation command of the energy storage cluster. When the initial power allocation command of the energy storage cluster is less than the grid dispatch command, it means that the output needs to be increased to make up the difference; when When the initial power allocation command of the energy storage cluster is greater than the grid dispatch command, the output needs to be reduced; when When the total initial power allocation command is exactly equal to the grid dispatch command, no error correction is required. The EMS stores the calculated AGC command tracking error in a real-time database.

[0154] S33. Use AGC instructions to track errors and perform PI control to obtain error correction power instructions.

[0155] In this embodiment of the invention, the EMS reads the AGC command tracking error of the current control cycle and the cumulative value of the AGC command tracking error of each historical control cycle from the real-time database. It then uses a proportional-integral (PI) controller to adjust the error signal, generating error correction power commands for each energy storage unit. The EMS employs a PI correction strategy that controls each energy storage unit separately. Each energy storage unit is equipped with an independent PI controller, with its own proportional and integral adjustment coefficients. Based on the same AGC command tracking error, the EMS calculates its corresponding error correction power command separately to accommodate the differences in response characteristics among different energy storage units. The specific error correction power command for each energy storage unit is calculated using the following formula:

[0156] ;

[0157] In the formula, For the first Each energy storage unit in the current control cycle Time-based error correction power command; For the first The proportional control coefficient of the PI controller of each energy storage unit is used to quickly respond to the instantaneous error of the current control cycle; For the current control cycle AGC instruction tracking error at any given time; For the first The integral adjustment coefficient of the PI controller of each energy storage unit is used to eliminate historical accumulated errors and improve steady-state tracking accuracy; From the initial control cycle (which is 0) to the current control cycle The sum of tracking errors for all AGC commands. The proportional and integral control coefficients are pre-set by the system operating procedures and stored in the EMS configuration database. The EMS stores the calculated error correction power commands for each energy storage unit in a real-time database.

[0158] S34. Perform summation calculations using each initial power allocation command and error correction power command to obtain the corrected energy storage power command.

[0159] In this embodiment of the invention, the EMS reads the initial power allocation command of each energy storage unit from the real-time database and the error correction power command of each energy storage unit calculated in step S33. It then performs a summation operation on the initial power allocation command and the corresponding error correction power command of the same energy storage unit to obtain the corrected energy storage power command for each energy storage unit. Specifically, the following formula is used for calculation:

[0160] ;

[0161] In the formula, For the first Each energy storage unit in the current control cycle Real-time correction of energy storage power commands.

[0162] After receiving the corrected energy storage power commands from each energy storage unit, the EMS also needs to verify their power ramp-up rate constraints. The power change rate of each energy storage unit must not exceed its maximum ramp-up rate, i.e., the following constraint must be satisfied:

[0163] ;

[0164] In the formula, For the first Each energy storage unit in the previous control cycle Real-time correction of energy storage power commands; For the first The maximum ramp rate of each energy storage unit, i.e., the maximum allowable power change per unit time, is predetermined by the equipment parameters of each unit. If the absolute value of the change in the corrected energy storage power command of a certain energy storage unit relative to the previous control cycle exceeds the allowable change at its maximum ramp rate, the EMS limits the corrected energy storage power command of that unit to the allowable ramp range, ensuring that the final corrected energy storage power command meets the equipment ramp rate constraints. The EMS stores the corrected energy storage power commands of each energy storage unit after ramp rate verification in a real-time database.

[0165] Step 106: Calculate the target power allocation command using the energy storage unit status information and the corrected energy storage power command, and allocate power in combination with the safe limit range formed by the available charging and discharging power margin.

[0166] SOC Over-Limit Risk Factor: This refers to the ratio of the degree to which the current state of charge of each energy storage unit deviates from the expected reference value to the width of the current effective operating range. The larger the value, the closer the state of charge is to the equivalent boundary, and the higher the risk of over-limit.

[0167] SOC protection factor: refers to the protective scaling factor of each energy storage unit obtained by mapping the SOC over-limit risk factor through an exponential function. The value range is greater than 0 and less than or equal to 1. It is used to perform multiplicative correction on the modified energy storage power command. The higher the SOC over-limit risk, the smaller the protection factor.

[0168] Energy storage unit converter: also known as energy storage converter (Power Conversion System, PCS), refers to the power conversion device that connects the energy storage battery and the power grid. It is used to receive power commands and control the energy storage unit to perform charging and discharging operations according to the commands.

[0169] Differential power command: When the target power allocation command of an energy storage unit exceeds the safe limit range, the difference between the original command and the limit boundary value indicates that the power portion reduced due to the limit needs to be redistributed to ensure that the total output fully tracks the grid dispatch command.

[0170] Furthermore, step 106 may include the following sub-steps:

[0171] S41. Calculate the SOC over-limit risk factor for each energy storage unit using the energy storage unit status information.

[0172] In this embodiment of the invention, the EMS reads the energy storage unit status information of each energy storage unit from the real-time database, including the state of charge, the equivalent SOC lower limit and equivalent SOC upper limit adjusted in step S13, and the expected SOC reference value, and calculates the SOC over-limit risk factor for each energy storage unit in the current control cycle. The SOC over-limit risk factor is used to quantitatively assess the proportion of the degree to which the current state of charge of each energy storage unit deviates from the expected reference value relative to the width of the current effective operating range. The larger the value, the closer it is to the equivalent boundary, and the higher the SOC over-limit risk. Specifically, it is calculated using the following formula:

[0173] ;

[0174] In the formula, For the first Each energy storage unit in the current control cycle Risk factors for exceeding SOC limits at any given time; This represents the expected SOC reference value. The physical meaning of this formula is: the numerator represents the absolute deviation of the current SOC from the expected reference value, and the denominator represents the width of the current equivalent SOC operating range. The larger the ratio of the two, the closer the SOC is to the equivalent boundary, and the higher the risk of exceeding the limit. EMS stores the calculated SOC limit exceeding risk factors for each energy storage unit in a real-time database.

[0175] S42. Calculate the SOC protection coefficient of each energy storage unit using the SOC over-limit risk factor.

[0176] In this embodiment of the invention, the EMS reads the SOC over-limit risk factor of each energy storage unit from the real-time database and maps the SOC over-limit risk factor to the SOC protection coefficient of each energy storage unit using an exponential function. The SOC protection coefficient is used to protectively scale the modified energy storage power command. The higher the SOC over-limit risk, the smaller the protection coefficient, thus providing stronger suppression of the power command and preventing the energy storage unit from over-limiting due to continued adjustment in the same direction. Specifically, it is calculated using the following formula:

[0177] ;

[0178] In the formula, For the first Each energy storage unit in the current control cycle The SOC protection factor at time t, with a value range of . When SOC exceeds the limit risk factor hour, This indicates that the current SOC is exactly at the expected reference value, and no protective correction is needed; as Increase The exponential decay and approaching 0 indicates that the greater the limit on SOC, the higher the risk and the stronger the suppression of power command. To protect the sensitivity coefficient, the system operation procedure pre-sets and stores it in the EMS configuration database based on the SOC sensitivity of the energy storage battery. This is used to adjust the response rate of the protection coefficient to changes in risk factors. The EMS stores the calculated SOC protection coefficient of each energy storage unit in a real-time database.

[0179] S43. The SOC protection coefficient and the modified energy storage power command are multiplied to obtain the target power allocation command for each energy storage unit.

[0180] In this embodiment of the invention, the EMS reads the SOC protection coefficient of each energy storage unit from the real-time database and the corrected energy storage power command of each energy storage unit calculated in step 105. The SOC protection coefficient and the corrected energy storage power command of the same energy storage unit are multiplied to obtain the target allocated power command for each energy storage unit. Specifically, the following formula is used for calculation:

[0181] ;

[0182] In the formula, For the first Each energy storage unit in the current control cycle The target power allocation command at any given time. The physical meaning of this multiplication operation is: scaling the modified energy storage power command through the SOC protection factor, so that energy storage units with higher SOC risk bear less regulation power, thereby preventing energy storage units from exceeding the safe operating range of SOC due to continued regulation in the same direction. The EMS stores the calculated target power allocation command for each energy storage unit in a real-time database.

[0183] S44. Determine whether the power allocation command for each target is within the safe limit range formed by the available margin of charging and discharging power.

[0184] In this embodiment of the invention, the EMS reads the discharge availability margin and charge availability margin of each energy storage unit calculated in step 102 from the real-time database, so as to... For the lower limit, The upper limit is used to define the safe range for each energy storage unit in the current control cycle. Each energy storage unit's target power allocation command is then checked to determine whether it falls within this safe range, i.e., whether it meets the following constraints:

[0185] ;

[0186] If the target power allocation command of a certain energy storage unit satisfies the above inequality, it is determined that it is within the safe limit range; if it does not satisfy the inequality, it is determined that it exceeds the safe limit range.

[0187] S45. If in the current state, the power allocation command for each target will be sent to the corresponding energy storage unit converter and executed.

[0188] In this embodiment of the invention, for the energy storage unit that is determined to be within the safe limit range in step S44, the EMS takes the target power allocation command as the final power command and sends it to the corresponding energy storage converter controller via fieldbus or industrial Ethernet. The energy storage converter performs the corresponding charging and discharging operation according to the received power command.

[0189] S46. If not, the target power allocation command for the corresponding energy storage unit will be limited to the boundary value of the safe limit range, and the difference power command generated by the limit will be allocated again and then sent out for execution.

[0190] In this embodiment of the invention, for energy storage units where the target power allocation command is determined to exceed the safe limit range in step S44, the EMS first limits the target power allocation command of the energy storage unit to the boundary value of the safe limit range. Specifically, if Then the power command will be forcibly limited to (Discharge upper limit boundary value); if Then the power command will be forcibly limited to (Charging lower limit boundary value). Limiting operation ensures that the final power command issued to the energy storage unit is always within the safe and adjustable range of the device.

[0191] Simultaneously, the EMS calculates the differential power command generated by the limiting operation, which is the difference between the original target allocated power command and the limit-adjusted boundary value. This differential power command represents the power reduction due to limiting; without compensation, the total output of the energy storage cluster will not be able to fully track the grid dispatch command. The EMS then performs a secondary allocation of this differential power command according to the available margin ratio of the remaining non-limited energy storage units, distributing the differential power command to energy storage units with remaining available margins. After the secondary allocation is completed, the EMS updates the final power command of each energy storage unit and sends both the limited command and the newly added command after the secondary allocation to the corresponding energy storage converter controller for execution, ensuring that the total output of the energy storage cluster fully tracks the grid dispatch command.

[0192] In an optional embodiment, the following steps may also be included:

[0193] A1. Construct the SOC dynamic update equation for each energy storage unit and set SOC safe operation range constraints.

[0194] In this embodiment of the invention, the EMS pre-constructs a dynamic update equation for the State of Charge (SOC) of each energy storage unit based on equipment parameters such as the rated capacity, charging and discharging efficiency, and control cycle of each energy storage unit, and sets a safe operating range constraint for the SOC of each energy storage unit. The dynamic update equation for SOC describes the dynamic update law of the energy storage unit's SOC as the charging and discharging power changes, and is specifically expressed by the following formula:

[0195] ;

[0196] In the formula, For the first The energy storage unit in the first The state of charge of a control cycle, that is, the new state of charge after being updated in one control cycle. For the first The energy storage unit in the first Discharge power per control cycle; For the first The energy storage unit in the first Charging power per control cycle; For the first Discharge efficiency of each energy storage unit; For the first The charging efficiency of each energy storage unit; For the first The rated capacity of each energy storage unit.

[0197] EMS also sets SOC safe operating range constraints for each energy storage unit, meaning that the state of charge of each energy storage unit should be maintained between the allowable lower and upper limits of SOC in any control cycle. The specific constraint formula is as follows:

[0198] ;

[0199] In the formula, For the first The minimum allowable SOC operation limit for each energy storage unit is predetermined by the equipment parameters and operating procedures of the energy storage battery. For the first The maximum allowable SOC (State of Charge) for each energy storage unit is also predetermined by the equipment parameters and operating procedures of the energy storage battery. The physical meaning of this constraint formula is: [The following is a continuation of the previous sentence, likely related to a formula or rule.] Each energy storage unit in any control cycle The state of charge at any given time must not be lower than its permissible lower limit. It must not exceed its permitted upper limit. This ensures that the energy storage unit always operates within the safe SOC range, avoiding equipment damage or protection shutdown due to over-discharge or over-charge.

[0200] In addition, EMS calculates the SOC safety margin for each energy storage unit based on the relationship between its current SOC and its safe operating range. The SOC safety margin describes how close the current SOC is to the safe operating range, and is calculated using the following formula:

[0201] ;

[0202] In the formula, For the first The energy storage unit in the first The SOC safety margin for each control cycle. The physical meaning of this formula is: take the smaller value between the current SOC's distance from the lower SOC limit and its distance from the upper SOC limit as the safety margin. A larger safety margin indicates that the current SOC is closer to the middle region of the safe zone, and the risk is lower as the limit is exceeded; a smaller safety margin indicates that the current SOC is closer to the boundary of the safe zone, and the risk is higher as the limit is exceeded. EMS stores the above SOC dynamic update equation, SOC safe operating zone constraints, and SOC safety margin calculation formula in the configuration database.

[0203] A2. Under the constraints of the SOC safe operating range, the actual charging and discharging power output by the energy storage unit after the issuance of the power allocation command for each target is input into the corresponding SOC dynamic update equation for solution, and the corresponding new state of charge is obtained.

[0204] In this embodiment of the invention, after each energy storage unit converter performs charging and discharging operations according to the final power command issued in step S45 or S46, the EMS collects the actual charging and discharging power (including actual discharging power) output by each energy storage unit in the current control cycle from the Battery Management System (BMS) of each energy storage unit via fieldbus or industrial Ethernet. and actual charging power The actual output charging and discharging power is substituted into the SOC dynamic update equation of the corresponding energy storage unit constructed in step A1 for solution, to obtain the new state of charge of each energy storage unit after charging and discharging in the current control cycle. It should be noted that the charging and discharging power input into the SOC dynamic update equation here is the actual physical power value output by the converter after executing the issued command, rather than the power command value before the issuance, so as to reflect the real energy state change of the energy storage unit.

[0205] A3. Update the energy storage unit status information using the new state of charge to obtain the new energy storage unit status information.

[0206] In this embodiment of the invention, the EMS calculates the new state of charge of each energy storage unit in step A2. Write to the real-time database to replace the original state of charge in the energy storage unit status information. At the same time, other relevant data in the energy storage unit status information are updated (such as updating the current actual charging and discharging power to the initial value of the next control cycle), forming new energy storage unit status information, which serves as the basis for power allocation calculation in the next control cycle.

[0207] A4. Based on the new energy storage unit status information and the new power grid dispatch instructions, jump to the step of calculating the available margin of charging and discharging power using the energy storage unit status information.

[0208] In this embodiment of the invention, the EMS enters the next control cycle. First, it receives a new grid dispatch command issued by the dispatch master station through the communication interface, and simultaneously reads the new energy storage unit status information updated in step A3 from the real-time database. Based on the new grid dispatch command and the new energy storage unit status information, the EMS jumps to step 102 (calculating the available margin of charging and discharging power using the energy storage unit status information), and repeats the complete control flow of steps 102 to 106 and steps A1 to A4, realizing the rolling optimization and real-time update output of energy storage AGC power allocation in each control cycle.

[0209] SOC dynamic update equation: refers to the mathematical relationship describing the dynamic update of the state of charge of the energy storage unit as the charging and discharging power changes. It is used to calculate the state of charge of the next control cycle based on the actual charging and discharging power output of the energy storage unit.

[0210] SOC safe operating range constraint: refers to the allowable range of state of charge set to ensure the safe operation of energy storage equipment. The state of charge of each energy storage unit shall not be lower than the allowable lower limit or higher than the allowable upper limit in any control cycle.

[0211] New State of Charge (SOC): This refers to the state of charge for the next control cycle obtained by substituting the actual charge and discharge power output of the energy storage unit in the current control cycle into the SOC dynamic update equation. It is used to update the state information of the energy storage unit for rolling calculation in the next control cycle.

[0212] This invention discloses an energy storage AGC power allocation control method considering State of Charge (SOC) operating constraints. The method first responds to the grid dispatch command of the target power grid and obtains the energy storage unit status information of each energy storage unit, providing a data foundation for subsequent power allocation. Second, it uses the energy storage unit status information to calculate the available charge / discharge power margin of each energy storage unit, determining the adjustable power boundary of each unit at the current moment. Subsequently, it constructs a multi-objective comprehensive cost function with AGC tracking accuracy, SOC equalization, battery life loss, and power smoothing as optimization objectives. The comprehensive cost value of this function is used to adjust the upper and lower limits of the equivalent SOC operating condition of each energy storage unit in real time, allowing the effective SOC range to adaptively shrink or recover with changes in the overall system performance, achieving unified coordination of multiple objectives within the same framework. Furthermore, based on the AGC adjustment direction determined by the grid dispatch command and using the adjusted equivalent SOC operating limits, it calculates the charge / discharge condition weights of each energy storage unit, thereby obtaining the initial power allocation command, enabling weighted allocation to begin. Ultimately, the process is conducted under constraints reflecting the overall operational status of the system, avoiding the problems of control direction conflicts and mutual weakening of effects caused by the superposition of multiple independent corrections in traditional methods. Then, PI control is used to track and correct errors in all initial power allocation commands to obtain corrected energy storage power commands, eliminating deviations between initial allocation commands and grid dispatch commands and ensuring the system's rapid and accurate response to dispatch commands. Finally, the corrected energy storage power commands are multiplied and corrected using SOC over-limit risk factors and protection coefficients to obtain the target power allocation command. Power allocation is then performed within a safe limiting range defined by the available charging and discharging power margin. Commands within the limiting range are directly issued and executed; commands exceeding the limiting range are limited to boundary values, and the difference in power commands are re-allocated before being issued and executed. This ensures that all issued commands are within the safe adjustable range of each energy storage unit, eliminating the risk of equipment protection shutdown or regulation failure due to command over-limits. This invention, through a complete control link of "comprehensive evaluation—dynamic boundary adjustment—weight allocation—closed-loop correction—safety limit allocation," unifies multiple requirements such as tracking accuracy, energy balance, lifespan maintenance, and safety constraints from the root of allocation decision-making. The links form a tight causal coupling rather than independent superposition, which can effectively avoid the SOC exceeding the limit due to long-term unidirectional charging and discharging of energy storage units, reduce AGC tracking errors and battery equivalent life loss, and improve the continuous regulation capability, operational safety, and multi-objective coordinated control effect of energy storage clusters participating in grid frequency regulation. It is suitable for application scenarios of energy storage power stations, energy storage clusters, and virtual power plants participating in AGC frequency regulation control in power systems with a high proportion of new energy.

[0213] The following is a simulation verification example:

[0214] This embodiment constructs a regional power grid AGC frequency regulation scenario containing 6 sets of electrochemical energy storage units to verify the effectiveness and superiority of the energy storage AGC power allocation control method considering SOC operation constraints proposed in this invention.

[0215] 1. Simulation Scenarios and Parameter Settings

[0216] The regional power grid has a rated load of 1200MW and a renewable energy installed capacity of 650MW, including 350MW of wind power and 300MW of photovoltaic power. The total rated power of the energy storage system is 120MW, and the total rated capacity is 240MWh. Each energy storage unit has a rated power of 20MW and a rated capacity of 40MWh. The initial SOC values ​​for each energy storage unit are set to 0.42, 0.48, 0.55, 0.61, 0.68, and 0.74, respectively. The SOC operating constraints are uniformly set to 0.20 to 0.90, and the expected SOC reference value is set to 0.55. The AGC control cycle is 2 seconds, and the total simulation time is 3600 seconds (i.e., 60 minutes). To fully verify the performance advantages of the method proposed in this invention, four comparison methods are set: a fixed ratio allocation method (allocated proportionally according to rated power), an allocation method considering only SOC correction, a traditional PI closed-loop allocation method, and the method proposed in this invention.

[0217] 2. Adaptive characteristics of power distribution

[0218] Depend on Figure 2 As can be seen, the method of this invention can dynamically adjust the regulation power undertaken by different energy storage units based on their power availability margin and SOC safety status when grid dispatch commands change rapidly. When the grid dispatch command requires discharge, energy storage units with higher SOC and larger discharge availability margins undertake more discharge power; when the grid dispatch command requires charging, energy storage units with lower SOC and larger charging availability margins undertake more charging power. This result verifies the effectiveness of calculating the charging and discharging condition weights based on the adjusted equivalent SOC operating limits in this invention—units with higher SOC and larger margins during discharge receive greater weights, and units with lower SOC and larger margins during charging receive greater weights, demonstrating the directional adaptive characteristics of the method of this invention.

[0219] 3. SOC balancing effect

[0220] Figure 3 The SOC variation curves of each energy storage unit during the AGC frequency regulation process are shown. Figure 3As can be seen, the initial SOC of different energy storage units varies (ranging from 0.42 to 0.74). However, under the control method proposed in this invention, the SOC of each energy storage unit remains within the set SOC operating constraint range of 0.20 to 0.90 throughout the entire simulation cycle, gradually approaching the expected SOC reference value of 0.55. This is because this invention constructs a multi-objective comprehensive cost function and dynamically adjusts the upper and lower limits of the equivalent SOC of each energy storage unit using real-time feedback of the comprehensive cost value. When the overall system performance deviates from the optimal state, the lower limit of the equivalent SOC is raised and the upper limit is lowered, tightening the effective range of SOC and correspondingly reducing the degree of SOC deviation in subsequent weight calculations. Simultaneously, the charging and discharging condition weights are calculated based on the adjusted upper and lower limits of the equivalent SOC, resulting in more significant suppression of units with higher or lower SOCs in the weight calculation. This avoids further deep discharge of units with lower SOCs and further deep charging of units with higher SOCs, reducing the risk of SOC exceeding limits. Compared with the fixed ratio allocation method, the method of the present invention no longer mechanically allocates power according to the rated capacity or power, but dynamically adjusts the output ratio according to the real-time status of each energy storage unit. Therefore, the SOC curves do not show a continuous deviation towards the upper or lower limit. This verifies that the method of the present invention can take into account both grid dispatch command tracking and energy state balance of energy storage units, improve the continuous frequency regulation capability of energy storage clusters, and avoid individual energy storage units from prematurely exiting regulation due to SOC exceeding the limit. It has good safety and engineering applicability.

[0221] 4. Comparison of battery equivalent lifespan loss

[0222] Figure 4The normalized comparison results of battery equivalent lifetime loss for four comparative methods are presented. Using a normalized loss of 1.00 for the fixed-ratio allocation method as a benchmark, the normalized loss for the SOC-corrected allocation method is 0.83, the normalized loss for the traditional PI closed-loop allocation method is 0.75, and the normalized loss for the method proposed in this invention is 0.58. The comparison results show that the fixed-ratio allocation method has the highest loss because it does not consider the SOC state, power variation amplitude, and cycle depth of each energy storage unit, easily causing some units to bear a large adjustment power for a long time, thus increasing battery cycle aging. While the SOC-corrected allocation method introduces the SOC state to adjust the allocation ratio, which improves the loss to some extent, it mainly adjusts the allocation ratio based on SOC and does not fully consider power smoothing and lifetime loss, thus its optimization effect is limited. The traditional PI closed-loop allocation method can improve AGC tracking accuracy, but when scheduling commands change frequently, it may cause large fluctuations in energy storage power, increasing the number of charge-discharge reverse switching, thus the loss is still relatively high. In comparison, the method of this invention exhibits the lowest equivalent loss. The fundamental reason for this is that the multi-objective comprehensive cost function constructed in this invention simultaneously incorporates optimization objectives across four dimensions: AGC tracking accuracy, SOC equalization, battery life loss, and power smoothing. The comprehensive cost value uniformly reflects the overall system performance, and the upper and lower limits of the equivalent SOC are dynamically adjusted based on real-time feedback of the comprehensive cost value, ensuring that weight calculations are always performed under constraints reflecting the overall system situation. Simultaneously, PI closed-loop correction guarantees the tracking accuracy of grid dispatch commands, and the SOC protection coefficient and differential secondary allocation mechanism further ensure the safety and complete tracking of power commands from the execution end. The complete control link described above—"comprehensive evaluation—boundary dynamic adjustment—weight allocation—closed-loop correction—safety limit allocation"—effectively avoids overcharging and discharging and high-frequency power surges while meeting frequency regulation requirements, unifying multiple optimization needs from the root of allocation decisions. This result demonstrates that the method proposed in this invention not only improves the effectiveness of AGC power allocation but also reduces battery degradation costs during frequency regulation participation, thereby enhancing the long-term economic efficiency of the energy storage system.

[0223] Please see Figure 5 , Figure 5 This is a structural block diagram of an energy storage AGC power distribution control system that considers SOC operating constraints, provided as an embodiment of the present invention.

[0224] This invention provides an energy storage AGC power distribution control system that considers SOC operating constraints, comprising:

[0225] The data acquisition module 501 is used to respond to the grid dispatching instructions of the target power grid and acquire the energy storage unit status information of each energy storage unit in the target power grid.

[0226] Margin calculation module 502 is used to calculate the available margin of charge and discharge power using energy storage unit status information;

[0227] The boundary adjustment module 503 is used to construct a multi-objective comprehensive cost function and adjust the upper and lower limits of the equivalent SOC operation of each energy storage unit according to the comprehensive cost value of the multi-objective comprehensive cost function.

[0228] The weight allocation module 504 is used to calculate the initial power allocation command for each energy storage unit based on the AGC adjustment direction determined by the power grid dispatch command and using the adjusted equivalent SOC operating upper and lower limits.

[0229] Error correction module 505 is used to perform error tracking and correction using all initial power allocation commands to obtain corrected energy storage power commands;

[0230] The safety verification module 506 is used to calculate the target power allocation command using the energy storage unit status information and the corrected energy storage power command, and to allocate power in combination with the safety limit range formed by the available charge and discharge power margin.

[0231] Since the above is a system corresponding to an energy storage AGC power allocation control method that considers SOC operating constraints, its implementation principle is consistent with that of an energy storage AGC power allocation control method that considers SOC operating constraints. For the sake of convenience and brevity, those skilled in the art can clearly understand that the specific working process of the system and modules described above can be referred to the corresponding process in the aforementioned method embodiments, and will not be repeated here.

[0232] Please see Figure 6 , Figure 6 This is a structural block diagram of an electronic device provided in an embodiment of the present invention.

[0233] An electronic device according to an embodiment of the present invention includes: a memory 601 and a processor 602. The memory 601 stores a computer program. When the computer program is executed by the processor 602, the processor 602 executes the energy storage AGC power allocation control method considering SOC operating constraints as described in the above embodiment.

[0234] Memory 601 may be an electronic memory such as flash memory, EEPROM (Electrically Erasable Programmable Read-Only Memory), EPROM, hard disk, or ROM. Memory 601 has storage space 603 for program code 613 for performing any of the method steps described above. For example, storage space 603 for program code may include individual program codes 613 for implementing the various steps in the methods described above. This program code may be read from or written to one or more computer program products. These computer program products include program code carriers such as hard disks, CDs, memory cards, or floppy disks. The program code may be compressed, for example, in a suitable form. When run by a computing processing device, this code causes the computing processing device to perform the various steps in the methods described above. This program code may be read from or written to one or more computer program products. These computer program products include program code carriers such as hard disks, CDs, memory cards, or floppy disks. The program code may be compressed, for example, in a suitable form. When this code is run by a computing device, it causes the computing device to perform the various steps in the energy storage AGC power allocation control method described above, which takes into account the SOC operating constraints.

[0235] This invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the energy storage AGC power allocation control method considering SOC operating constraints as described in the above embodiments.

[0236] This invention also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium. The computer program includes program instructions, wherein when the program instructions are executed by a computer, the computer performs the energy storage AGC power allocation control method considering SOC operating constraints as described in the above embodiments.

[0237] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0238] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, or indirect coupling or communication connection between apparatuses or units, and may be electrical, mechanical, or other forms.

[0239] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0240] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0241] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0242] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A power allocation control method for energy storage AGC considering SOC operating constraints, characterized in that, include: In response to the grid dispatching instructions of the target power grid, obtain the energy storage unit status information of each energy storage unit within the target power grid; The available charge / discharge power margin is calculated using the energy storage unit status information; Construct a multi-objective comprehensive cost function, and adjust the upper and lower limits of the equivalent SOC operation of each energy storage unit according to the comprehensive cost value of the multi-objective comprehensive cost function; The AGC adjustment direction is determined according to the power grid dispatch command, and the initial power allocation command of each energy storage unit is calculated using the adjusted equivalent SOC operating upper and lower limits. Error tracking and correction are performed using all the initial power allocation commands to obtain the corrected energy storage power command; The target power allocation command is calculated using the energy storage unit status information and the corrected energy storage power command, and the power allocation is performed in combination with the safe limit range formed by the available charge and discharge power margin.

2. The energy storage AGC power allocation control method considering SOC operating constraints according to claim 1, characterized in that, The construction of the multi-objective comprehensive cost function, and the adjustment of the equivalent SOC upper and lower limits of each energy storage unit based on the comprehensive cost value of the multi-objective comprehensive cost function, includes: With AGC tracking accuracy, SOC equalization, battery life loss and power smoothing as objectives, a multi-objective comprehensive cost function for the target power grid is constructed. The energy storage unit's state information is input into the multi-objective comprehensive cost function for solution, yielding the comprehensive cost value. The upper and lower limits of the equivalent SOC operation within the energy storage unit's state information are adjusted based on the comprehensive cost value.

3. The energy storage AGC power allocation control method considering SOC operating constraints according to claim 1, characterized in that, The step of determining the AGC adjustment direction based on the grid dispatch command and calculating the initial power allocation command for each energy storage unit using the adjusted equivalent SOC operating upper and lower limits includes: The AGC adjustment direction is determined according to the power grid dispatching command, and the upper and lower limits of the adjusted equivalent SOC and the state of charge are used to calculate the charging and discharging condition weights of each energy storage unit. The initial power allocation command for each energy storage unit is obtained by multiplying the power grid dispatch command with the charging and discharging condition weights.

4. The energy storage AGC power allocation control method considering SOC operating constraints according to claim 1, characterized in that, The step of using all the initial power allocation commands for error tracking and correction to obtain the corrected energy storage power command includes: The total initial charge / discharge power command is calculated using all of the aforementioned initial power allocation commands; The difference between the power grid dispatch command and the total initial charge / discharge power command is calculated to obtain the AGC command tracking error. The AGC command is used to track the error and perform PI control to obtain the error correction power command; The initial power allocation command and the error correction power command are summed to obtain the corrected energy storage power command.

5. The energy storage AGC power allocation control method considering SOC operating constraints according to claim 1, characterized in that, The step of calculating the target power allocation command using the energy storage unit status information and the corrected energy storage power command, and allocating power within a safe limiting range formed by the available charge and discharge power margin, includes: The SOC over-limit risk factor of each energy storage unit is calculated using the energy storage unit status information; The SOC protection factor of each energy storage unit is calculated using the SOC over-limit risk factor. The target power allocation command for each energy storage unit is obtained by multiplying the SOC protection coefficient with the modified energy storage power command. Determine whether each of the target power allocation commands is within the safe limit range formed by the available charging and discharging power margin; If so, the target power allocation commands are sent to the corresponding energy storage unit converters and executed. If not, the target power allocation command for the corresponding energy storage unit will be limited to the boundary value of the safe limit range, and the difference power command generated by the limit will be redistributed and then sent out for execution.

6. The energy storage AGC power allocation control method considering SOC operating constraints according to any one of claims 1-5, characterized in that, Also includes: Construct the SOC dynamic update equations for each of the energy storage units and set SOC safe operating range constraints; Under the constraints of the SOC safe operating range, the actual charging and discharging power output by the energy storage unit after the issuance of each target power allocation command is input into the corresponding SOC dynamic update equation for solving, and the corresponding new state of charge is obtained. The new state of charge is used to update the energy storage unit state information to obtain new energy storage unit state information; Based on the new energy storage unit status information and the new power grid dispatch instructions, the process jumps to execute the step of calculating the available charge and discharge power margin using the energy storage unit status information.

7. A power distribution control system for energy storage AGC considering SOC operating constraints, characterized in that, include: The data acquisition module is used to respond to the grid dispatching instructions of the target power grid and acquire the energy storage unit status information of each energy storage unit in the target power grid; The margin calculation module is used to calculate the available margin of charging and discharging power using the energy storage unit's state information; The boundary adjustment module is used to construct a multi-objective comprehensive cost function and adjust the upper and lower limits of the equivalent SOC operation of each energy storage unit according to the comprehensive cost value of the multi-objective comprehensive cost function. The weight allocation module is used to calculate the initial allocation power command for each energy storage unit based on the AGC adjustment direction determined by the power grid dispatch command and using the adjusted equivalent SOC operating upper and lower limits. An error correction module is used to perform error tracking and correction using all the initial power allocation commands to obtain a corrected energy storage power command. The safety verification module is used to calculate the target power allocation command using the energy storage unit status information and the corrected energy storage power command, and to perform power allocation in combination with the safety limit range formed by the available charge and discharge power margin.

8. An electronic device, characterized in that, The device includes a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor causes the processor to perform the steps of the energy storage AGC power allocation control method considering SOC operating constraints as described in any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed, it implements the energy storage AGC power allocation control method considering SOC operating constraints as described in any one of claims 1-6.

10. A computer program product, characterized in that, The computer program product includes a computer program stored on a non-transitory computer-readable storage medium, the computer program including program instructions, wherein when the program instructions are executed by a computer, the computer performs the energy storage AGC power allocation control method considering SOC operating constraints as described in any one of claims 1-6.

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