Smooth power and frequency modulation auxiliary service wind power plant energy storage composite control method and device

Abstract

The invention relates to a smooth power and frequency modulation auxiliary service wind power plant energy storage composite control method and device, and the method comprises the steps: obtaining a total AGC power instruction of a power system under the condition of power disturbance of a power grid, carrying out the mode decomposition processing of the total AGC power instruction, obtaining an AGC power instruction of a wind power plant energy storage system, and carrying out the mode decomposition processing of the AGC power instruction; determining a smooth control dead zone of the wind power plant energy storage system according to the historical grid-connected power and the current wind power, and respectively controlling a smooth output value and a frequency modulation output value of the wind power plant energy storage system according to the current wind power, the current charge state, the smooth control dead zone and the AGC power instruction. As the smooth control dead zone represents the fluctuation interval of smooth output when the wind power plant energy storage system meets the grid-connected standard, energy in the smooth control dead zone is used for participating in power grid frequency modulation and charge state recovery of the energy storage system, the wind power plant energy storage system can be ensured to always meet the grid-connected standard, and the grid-connected power supply efficiency is improved. And stable operation of the power system is ensured.

Description

Technical Field

[0001] This application relates to the field of energy storage system control technology, and in particular to a wind farm energy storage composite control method and device that combines power smoothing and frequency regulation auxiliary services. Background Technology

[0002] When large-scale wind farms (hereinafter referred to as wind farms) are connected to the grid, the impact of grid-connected power fluctuations on the safe and stable operation of the power system cannot be ignored. Energy storage systems (ESS) are the main way to smooth out power fluctuations when wind power is connected to the grid because they can respond quickly to power, are easy to implement, and require little installation space.

[0003] To improve the efficiency of energy storage systems, these systems can assist in power system frequency regulation. However, current wind farm energy storage systems, when simultaneously participating in smoothing wind power fluctuations and power system frequency regulation, do not consider the impact of frequency regulation participation on wind power grid connection power. This results in grid connection power failing to meet grid connection standards, affecting the safe and stable operation of the power system. Summary of the Invention

[0004] Therefore, it is necessary to provide a wind farm energy storage composite control method and device that combines smooth power and frequency regulation auxiliary services to address the above-mentioned technical problems.

[0005] In a first aspect, this application provides a wind farm energy storage composite control method for smoothing power and frequency regulation ancillary services, applied in a power system, wherein the power system includes a power grid, wind turbine generators, and at least one wind farm energy storage system, the wind farm energy storage system being connected to the wind turbine generators and the power grid respectively; the method includes:

[0006] In the event of a power disturbance in the power grid, the total AGC power command of the power system is obtained;

[0007] The total AGC power command is subjected to mode decomposition processing to obtain the AGC power command of the wind farm energy storage system;

[0008] Acquire the current wind power of the wind turbine, the historical grid-connected power data of the wind farm energy storage system, and the current state of charge.

[0009] Based on the historical grid-connected power and the current wind power, the smooth control dead zone of the wind farm energy storage system is determined; the smooth control dead zone represents the fluctuation range of the wind farm energy storage system's output while meeting grid connection standards.

[0010] Based on the current wind power, the current state of charge, the smooth control dead zone, and the AGC power command, the smooth output value and frequency regulation output value of the wind farm energy storage system are controlled respectively.

[0011] In one embodiment, determining the smooth control dead zone of the wind farm energy storage system based on the historical grid-connected power and the current wind power includes:

[0012] Based on the historical grid-connected power, the first grid-connected power range of the first sub-time period and the second grid-connected power range of the second sub-time period are determined respectively; the duration of the first sub-time period is shorter than the duration of the second sub-time period.

[0013] Based on the intersection of the first grid-connected power range and the second grid-connected power range, the range of change in the grid-connected power of the wind farm energy storage system at the current moment is determined;

[0014] The wind power is input into a first-order digital low-pass filter to obtain the initial grid-connected power of the wind farm energy storage system.

[0015] The smoothing control dead zone is determined based on the difference between the initial grid-connected power and the upper limit of the variation range, and the difference between the initial grid-connected power and the lower limit of the variation range.

[0016] In one embodiment, controlling the smoothed output value and frequency-regulated output value of the wind farm energy storage system based on the current wind power, the current state of charge, the smoothed control dead zone, and the AGC power command respectively includes:

[0017] The current wind power is input into a first-order digital low-pass filter to obtain the initial grid-connected power of the wind farm energy storage system.

[0018] The initial smooth output value of the wind farm energy storage system is determined based on the difference between the initial grid-connected power and the current wind power.

[0019] Based on the initial smoothed output value, the smoothed control dead zone, and the current state of charge, determine the corrected power required for the wind farm energy storage system to restore its state of charge;

[0020] The smooth output value of the wind farm energy storage system is controlled based on the initial smooth output value and the corrected power.

[0021] The frequency regulation output value of the wind farm energy storage system is controlled based on the smoothed output value, the current wind power, the smoothed control dead zone, and the AGC power command.

[0022] In one embodiment, controlling the frequency regulation output value of the wind farm energy storage system based on the smoothed output value, the current wind power, the smoothed control dead zone, and the AGC power command includes:

[0023] The actual grid-connected power of the wind farm energy storage system is determined based on the smoothed output value and the current wind power.

[0024] The available frequency regulation power of the wind farm energy storage system is determined based on the actual grid-connected power and the smooth control dead zone.

[0025] The frequency regulation output value of the wind farm energy storage system is controlled based on the smaller value between the available frequency regulation power and the AGC power command.

[0026] In one embodiment, determining the available frequency regulation power of the wind farm energy storage system based on the actual grid-connected power and the smooth control dead zone includes:

[0027] When the AGC power command indicates that the frequency regulation output of the wind farm energy storage system is reduced, the absolute value of the first difference between the upper limit of the smooth control dead zone and the actual grid-connected power is taken as the available frequency regulation power.

[0028] When the AGC power command indicates an increase in the frequency regulation output of the wind farm energy storage system, the absolute value of the second difference between the lower limit of the smooth control dead zone and the actual grid-connected power is taken as the available frequency regulation power.

[0029] In one embodiment, determining the corrected power required for the wind farm energy storage system to restore its state of charge based on the initial smoothed output value, the smoothed control dead zone, and the current state of charge includes:

[0030] When the current state of charge is within the normal range, the corrective power is zero;

[0031] When the current state of charge is in the primary recovery range and the secondary emergency recovery range, the current state of charge, the upper and lower limits of the smooth control dead zone, and the initial smooth output value are input into a preset Logistic function model to obtain the corrected power.

[0032] When the current state of charge is in the emergency recovery zone, the corrected power is determined based on the absolute value of the difference between the upper or lower limit of the smooth control dead zone and the initial smooth output value.

[0033] In one embodiment, the step of performing mode decomposition processing on the total AGC power command to obtain the AGC power command of the wind farm energy storage system includes:

[0034] The total AGC power command is input into a preset variational mode decomposition model to obtain multiple modal components with different center frequencies.

[0035] The AGC power command is determined based on the sum of modal components whose center frequency is greater than a preset frequency.

[0036] In one embodiment, the power system includes multiple wind farm energy storage systems;

[0037] The method further includes:

[0038] Based on the current state of charge of the multiple wind farm energy storage systems, the multiple wind farm energy storage systems are divided into a first sequence and a second sequence; the first sequence includes wind farm energy storage systems whose current state of charge is less than a preset state of charge threshold, and the second sequence includes wind farm energy storage systems whose current state of charge is greater than or equal to the preset state of charge threshold.

[0039] Based on the total AGC power command, determine the priorities of the first sequence and the second sequence;

[0040] When the total frequency regulation output of the target sequence meets the frequency regulation requirements of the power system, the energy storage systems of each wind farm in the target sequence are controlled to participate in frequency regulation; the target sequence is the sequence with higher priority between the first sequence and the second sequence.

[0041] If the total frequency regulation output of the target sequence does not meet the frequency regulation requirements of the power system, the energy storage systems of each wind farm in another sequence are controlled to participate in frequency regulation.

[0042] In one embodiment, controlling the frequency regulation output of the wind farm energy storage system based on the current wind power, the current state of charge, the smooth control dead zone, and the AGC power command includes:

[0043] Based on the current wind power, the current state of charge, the control dead zone, and the AGC power command, the available frequency regulation power of each target wind farm energy storage system is obtained; the target wind farm energy storage system is the wind farm energy storage system participating in frequency regulation.

[0044] Obtain the sum of available frequency regulation power for each target wind farm;

[0045] The output weight of the target wind farm energy storage system is determined based on the ratio of each available frequency-modulated power to the sum of the available frequency-modulated power.

[0046] The frequency regulation output value of the corresponding target wind farm energy storage system is controlled based on the product of the total AGC power command and the output weight.

[0047] Secondly, this application also provides a wind farm energy storage composite control device for smoothing power and frequency regulation auxiliary services, applied in a power system, wherein the power system includes a power grid, wind turbine generators, and at least one wind farm energy storage system, wherein the wind farm energy storage system is connected to the wind turbine generators and the power grid respectively; the device includes:

[0048] The AGC instruction acquisition module is used to acquire the total AGC power instruction of the power system when the power grid experiences a power disturbance, and to perform mode decomposition processing on the total AGC power instruction to acquire the AGC power instruction of the wind farm energy storage system.

[0049] The grid-connected data acquisition module is used to acquire the current wind power of the wind turbine, the historical grid-connected power data of the wind farm energy storage system, and the current state of charge.

[0050] The control dead zone determination module is used to determine the smooth control dead zone of the wind farm energy storage system based on the historical grid-connected power and the current wind power; the smooth control dead zone represents the fluctuation range of the wind farm energy storage system's output while meeting grid connection standards.

[0051] The output power control module is used to control the smooth output value and frequency regulation output value of the wind farm energy storage system according to the current wind power, the current state of charge, the smooth control dead zone and the AGC power command.

[0052] In the aforementioned wind farm energy storage composite control method and device for smoothing power and frequency regulation auxiliary services, a smoothing control dead zone is introduced. Since the smoothing control dead zone represents the range of power output fluctuations of the wind farm energy storage system while meeting grid connection standards, the energy within the smoothing control dead zone is used to participate in grid frequency regulation and the state of charge recovery of the energy storage system. This can ensure that the wind farm energy storage system can always meet grid connection standards and guarantee the stable operation of the power system. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This is a flowchart illustrating a wind farm energy storage composite control method that combines power smoothing and frequency regulation auxiliary services in one embodiment.

[0055] Figure 2 This is a schematic diagram of the four state intervals of the state of charge of a wind farm energy storage system in one embodiment;

[0056] Figure 3a The Logistic function represents the positive fluctuation of grid-connected power.

[0057] Figure 3b The Logistic function represents the negative fluctuation of grid-connected power.

[0058] Figure 4 The curve represents the smoothing of grid-connected power before and after the transition and the smoothing of the control dead zone;

[0059] Figure 5 The grid-connected power curves for the two selected evaluation windows;

[0060] Figure 6 The modal components are the decomposed components of the total AGC power command of the power system.

[0061] Figure 7 This indicates the AGC power of the energy storage system in the power system before and after a single wind farm energy storage system participates in AGC frequency regulation;

[0062] Figure 8a The figures represent the power curves of the energy storage system under the conditions of smoothing wind power fluctuations without SOC optimization and the energy storage system under the SOC optimization strategy for smoothing wind power fluctuations.

[0063] Figure 8b The power curves of the energy storage system are shown for energy storage systems participating in composite scenarios without SOC optimization and for energy storage systems participating in composite scenarios with SOC optimization strategies.

[0064] Figure 8c This represents the SOC curves under four different strategies;

[0065] Figure 9 The curves represent the AGC power of the two wind farm energy storage systems and the total AGC power of the wind farm energy storage systems in the power system.

[0066] Figure 10 The curve showing the change in total AGC power of wind farm energy storage systems in the power system when multiple wind farm energy storage systems are involved;

[0067] Figure 11a This represents the power curve of a wind farm energy storage system recovering its state of charge (SOC) within the smooth control dead zone.

[0068] Figure 11b This represents the power curve of another wind farm energy storage system recovering its State of Charge (SOC) within the smooth control dead zone;

[0069] Figure 11cThis represents the SOC curves of the two energy storage systems within the smooth control dead zone;

[0070] Figure 12 The curve representing the change in the overall SOC (State of Charge) involving multiple wind farm energy storage systems;

[0071] Figure 13 This is a structural block diagram of a wind farm energy storage composite control device that provides smooth power and frequency regulation auxiliary services in one embodiment.

[0072] Figure 14 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0073] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0074] This application provides a wind farm energy storage composite control method for smoothing power generation and providing frequency regulation ancillary services, which can be applied to a power system. The power system includes a power grid, wind turbine generators, and at least one wind farm energy storage system. The wind farm energy storage system is connected to both the wind turbine generators and the power grid. The wind farm energy storage system can be used to smooth grid connection fluctuations and participate in grid frequency regulation together with conventional generators in the power grid.

[0075] In one embodiment, such as Figure 1 As shown, the wind farm energy storage composite control method for smooth power and frequency regulation auxiliary services may include steps 100-500.

[0076] Step 100: In the event of a power disturbance in the power grid, obtain the total AGC power command of the power system.

[0077] Power disturbances in the power grid are mainly caused by changes in the grid frequency. Automatic Generation Control (AGC), also known as secondary frequency regulation, refers to the process by which generator sets provide sufficient adjustable capacity and a certain regulation rate to track the grid frequency in real time within permissible regulation deviations, so as to keep the power system frequency stable. Total AGC power represents the total frequency regulation output of conventional generator sets and wind farm energy storage systems under ideal conditions, as shown in equation (1).

[0078] (1)

[0079] in, This indicates the total power deficit required for the frequency to recover to the agreed range; Indicates the total AGC power; This indicates the frequency regulation output of a conventional generator set; This indicates the frequency regulation output of the wind farm's energy storage system; R represents the frequency regulation output of the k-th conventional generator unit, and R represents the number of conventional generator units participating in frequency regulation. This represents the frequency regulation output of the i-th wind farm energy storage system, and M represents the number of wind farm energy storage systems participating in frequency regulation. Conventional generator sets refer to conventional generator sets in the power grid, such as thermal power units.

[0080] The total AGC power can be calculated based on the tie-line bias control (TBC) method:

[0081] (2)

[0082] in, B represents the power deviation of the regional tie line when a power disturbance occurs, and B represents the power system frequency deviation coefficient. It represents the change in frequency.

[0083] Step 200: Perform modal decomposition processing on the total AGC power command to obtain the AGC power command of the wind farm energy storage system.

[0084] Based on the characteristics of conventional generator sets and wind farm energy storage systems, conventional generator sets have a large frequency regulation capacity but a slow response, while wind farm energy storage systems have a small frequency regulation capacity but a fast response. Therefore, the total AGC power command can be decomposed into modes, allocating the low-frequency and high-amplitude components to the conventional generator sets and the high-frequency and low-amplitude signals to the wind farm energy storage system. In other words, the AGC power command of the wind farm energy storage system is the high-frequency component of the total AGC power command.

[0085] Step 300: Obtain the current wind power of the wind turbine, the historical grid-connected power data of the wind farm energy storage system, and the current state of charge.

[0086] Current wind power output refers to the wind power output of the wind turbine at the current moment. Historical grid-connected power data represents the grid-connected power data over a past period. Current state of charge (SOC) represents the state of charge of the wind farm's energy storage system at the current moment.

[0087] Step 400: Determine the smooth control dead zone of the wind farm energy storage system based on historical grid-connected power and current wind power.

[0088] The smoothing control dead zone represents the range of power output fluctuations within a wind farm energy storage system while meeting grid connection standards. It can be calculated by obtaining the upper and lower limits of the allowable range of grid-connected power variation over a past period using historical grid-connected power data, and by obtaining the initial grid-connected power at the current moment using the current wind power output. The difference between the initial grid-connected power and the two limits yields the smoothing control dead zone. Energy within the smoothing control dead zone is used for the state-of-charge recovery of the wind farm energy storage system and for frequency regulation.

[0089] Step 500: Based on the current wind power, current state of charge, smooth control dead zone, and AGC power command, control the smooth output value and frequency regulation output value of the wind farm energy storage system respectively.

[0090] The smoothed output value of a wind farm energy storage system is approximately equal to the high-frequency component of the current wind power. Besides participating in frequency regulation, the wind farm energy storage system also needs to restore its state of charge (SOC), with SOC restoration taking precedence over frequency regulation participation. This means that energy in the smoothing control dead zone is prioritized for SOC restoration, and the remaining energy can be used for frequency regulation based on AGC power commands.

[0091] In this embodiment, when a power disturbance occurs in the power grid, the total AGC power command of the power system is obtained. The total AGC power command is then processed by mode decomposition to obtain the AGC power command of the wind farm energy storage system. Based on the historical grid-connected power and the current wind power, the smooth control dead zone of the wind farm energy storage system is determined. Based on the current wind power, the current state of charge, the smooth control dead zone, and the AGC power command, the smooth output value and frequency regulation output value of the wind farm energy storage system are controlled respectively. Since the smooth control dead zone represents the fluctuation range of the smooth output of the wind farm energy storage system under the condition of meeting the grid connection standard, the energy within the smooth control dead zone is used to participate in the grid frequency regulation and the state of charge recovery of the energy storage system. This can ensure that the wind farm energy storage system can always meet the grid connection standard and ensure the stable operation of the power system.

[0092] In one embodiment, the smooth control dead zone of the wind farm energy storage system is determined based on historical grid-connected power and current wind power, including steps 410-440.

[0093] Step 410: Based on historical grid-connected power, determine the first grid-connected power range for the first sub-time period and the second grid-connected power range for the second sub-time period. The duration of the first sub-time period is shorter than the duration of the second sub-time period.

[0094] For example, the first sub-time period can be the past 1 minute, and the second sub-time period can be the past 10 minutes.

[0095] The first grid-connected power range of the first sub-time period It can be calculated using the following formula:

[0096] (3)

[0097] in, This indicates the upper limit of the first grid-connected power range; Indicates the past The grid-connected power of the i-th sampling point within the time period; The coefficient representing the allowable power fluctuation according to grid connection standards is 0.1; Indicates the installed capacity of the wind turbine unit; This indicates the lower limit of the first grid-connected power range; m represents the sampling interval. This indicates traversing all Then take the minimum value; This indicates traversing all Then take the maximum value.

[0098] The second grid-connected power range within the second sub-time period It can be obtained from the following formula:

[0099] (4)

[0100] in, This indicates the upper limit of the second grid-connected power range; The coefficient representing the allowable power fluctuations according to grid connection standards is 1 / 3; This indicates the lower limit of the second grid-connected power range.

[0101] Step 420: Determine the range of change in grid-connected power of the wind farm energy storage system at the current moment based on the intersection of the first grid-connected power range and the second grid-connected power range.

[0102] The range of grid-connected power at the current moment It can be represented as:

[0103] (5)

[0104] Step 430: Input the current wind power into a first-order digital low-pass filter to obtain the initial grid-connected power of the wind farm energy storage system.

[0105] Initial grid-connected power It can be represented as:

[0106]

[0107] in, The transfer function of a first-order digital low-pass filter is given. The filter time constant is represented by s; the differential operator is represented by s. This indicates the current wind power output.

[0108] Step 440: Determine the smoothing control dead zone based on the difference between the initial grid-connected power and the upper limit of the variation range, and the difference between the initial grid-connected power and the lower limit of the variation range.

[0109] Smooth control dead zone It can be represented as:

[0110]

[0111] In one embodiment, the smooth output value and frequency regulation output value of the wind farm energy storage system are controlled according to the current wind power, the current state of charge, the smooth control dead zone, and the AGC power command, respectively, including steps 510-550.

[0112] Step 510: Input the current wind power into a first-order digital low-pass filter to obtain the initial grid-connected power of the wind farm energy storage system.

[0113] Step 520: Determine the initial smooth output value of the wind farm energy storage system based on the difference between the initial grid-connected power and the current wind power.

[0114] Initial smooth output value It can be represented as:

[0115]

[0116] Step 530: Determine the corrected power required for the wind farm energy storage system to restore its state of charge based on the initial smoothed output value, the smoothed control dead zone, and the current state of charge.

[0117] The energy within the smooth control dead zone is used for restoring the state of charge and participating in frequency modulation. To determine more precisely the energy allocation for restoring the state of charge and frequency modulation within the smooth control dead zone, such as... Figure 2 As shown, the state of charge (SOC) of a wind farm energy storage system can be divided into four state intervals: normal interval, primary recovery interval, secondary emergency recovery interval, and emergency recovery interval. The normal interval can be represented as 1 - SOC_ db ~SOC_ db The primary recovery interval can be represented as SOC_ db ~SOC_1 and 1-SOC_1~1-SOC_ db The secondary emergency recovery interval can be represented as SOC_1~SOC_2 and 1-SOC_2~1-SOC_1, and the emergency recovery interval can be represented as SOC_2~SOC_2. max and SOC_ min ~1-SOC_2. For example, SOC_ db The value can be 0.6, SOC_1 can be 0.7, and SOC_2 can be 0.8.

[0118] When the current state of charge (SOC) is within the normal range, the correction power is zero. This means that when the SOC is within the normal range, the wind farm's energy storage system has sufficient charging and discharging energy, and the energy within the smooth control dead zone primarily participates in frequency regulation; therefore, the correction power required to restore the SOC is zero.

[0119] When the current state of charge is in the primary recovery range and the secondary emergency recovery range, the current state of charge, the upper and lower limits of the smooth control dead zone, and the initial smooth output value are input into the preset Logistic function model to obtain the corrected power.

[0120] The Logistic function model is an S-shaped curve, such as... Figure 3a and Figure 3b As shown, this is used to constrain the changing trend of the state of charge of the wind farm energy storage system. Figure 3a This indicates a positive fluctuation in grid-connected power. Figure 3b This indicates negative fluctuations in grid-connected power. The Logistic function can be expressed as:

[0121]

[0122]

[0123] in, This represents the corrected power required for the i-th wind farm energy storage system to restore its state of charge during charging; This represents the corrected power required for the i-th wind farm energy storage system to restore its state of charge during discharge; n and This is a parameter that can be set according to actual needs.

[0124] Currently, the wind farm energy storage system is in the initial recovery phase of its state of charge (SOC), indicating a good SOC but with the potential for deterioration. At this stage, the primary focus is on AGC frequency regulation. However, when the wind farm energy storage system experiences high or low demand for load mitigation and operates at a high or low SOC, SOC recovery should be initiated. The required correction power for the i-th wind farm energy storage system to recover its SOC is defined as follows: for:

[0125]

[0126] in, It is obtained from equation (8); This represents the value of the Logistic function when the SOC exceeds 0.5, and is used to constrain the recovery of the wind farm energy storage system. This represents the value of the Logistic function when the SOC is below 0.5, and is used to constrain the recovery of the wind farm energy storage system.

[0127] When the current state of charge (SOC) is in the sub-emergency recovery range, the SOC of the wind farm energy storage system is at a high or low level, and restoring the SOC is the primary goal. At this time, the correction power required for the i-th wind farm energy storage system to restore its SOC is... for:

[0128]

[0129] When the current state of charge (SOC) is in the emergency recovery zone, the correction power is determined based on the absolute value of the difference between the upper or lower limit of the smooth control dead zone and the initial smooth output value. It can be understood that when the current SOC is in the emergency recovery zone, the wind farm energy storage system may lose its charging or discharging capacity. In this case, all the energy within the smooth control dead zone is used to restore the SOC. The correction power required for the i-th wind farm energy storage system to restore its SOC is... for:

[0130]

[0131] Step 540: Control the smooth output value of the wind farm energy storage system based on the initial smooth output value and the corrected power.

[0132] The smoothed output value of a wind farm energy storage system is the sum of the initial smoothed output value and the corrected power, which can be expressed as:

[0133]

[0134] in, This represents the smoothed output value of the energy storage system in the i-th wind farm.

[0135] Step 550: Control the frequency regulation output value of the wind farm energy storage system based on the smoothed output value, the current wind power, the smoothed control dead zone, and the AGC power command.

[0136] The remaining energy within the smooth control dead zone can be used to participate in AGC frequency modulation. Specifically, step 550 may include steps 551-553.

[0137] Step 551: Determine the actual grid-connected power of the wind farm energy storage system based on the smoothed output value and the current wind power.

[0138] The actual grid-connected power is the sum of the smoothed output value and the current wind power, which can be expressed as:

[0139]

[0140] in, This represents the actual grid-connected power of the energy storage system in the i-th wind farm; This represents the current wind power output of the wind turbine connected to the energy storage system of the i-th wind farm.

[0141] Step 552: Determine the available frequency regulation power of the wind farm energy storage system based on the actual grid-connected power and the smooth control dead zone.

[0142] When the sign of the AGC power command is positive, or it can be said that... This indicates a reduction in the frequency regulation output of the wind farm's energy storage system; when the sign of the AGC power command is negative, or in other words... This indicates an increase in the frequency regulation output of the wind farm's energy storage system. Among them, This represents the AGC power command for the i-th wind farm energy storage system. When the AGC power command indicates a decrease in the frequency regulation output of the wind farm energy storage system, the absolute value of the first difference between the upper limit of the smooth control dead zone and the actual grid-connected power can be used as the available frequency regulation power. When the AGC power command indicates an increase in the frequency regulation output of the wind farm energy storage system, the absolute value of the second difference between the lower limit of the smooth control dead zone and the actual grid-connected power can be used as the available frequency regulation power.

[0143] Step 553: Based on the smaller value between the available frequency regulation power and the AGC power command, control the frequency regulation output value of the wind farm energy storage system.

[0144]

[0145] Based on the above formula, the frequency regulation output value of the wind farm energy storage system can be obtained.

[0146] In one embodiment, the total AGC power command is processed by mode decomposition to obtain the AGC power command of the wind farm energy storage system, including steps 210-220.

[0147] Step 210: Input the total AGC power command into the preset variational mode decomposition model to obtain multiple modal components with different center frequencies.

[0148] Variational Mode Decomposition (VMD) is an adaptive, fully non-recursive signal processing method that decomposes a complex signal into multiple quasi-orthogonal mode components with specific center frequencies, thereby reducing mode aliasing. The VMD model can be expressed as:

[0149]

[0150] Where K represents the total number of modal components; This represents the k-th modal component; This represents the center frequency of the k-th modal component; This represents the first derivative with respect to time t; This represents the convolution operation; Used to solve the Hilbert transform of a signal.

[0151] By introducing Lagrange multipliers and penalty factors, equation (17) is transformed into an unconstrained optimization model, and solving it yields k modal components and their center frequencies. The solution method is not the focus of this invention and can be obtained based on known methods for solving variational mode decomposition models.

[0152] Step 220: Determine the AGC power command based on the sum of modal components whose center frequency is greater than the preset frequency.

[0153] The preset frequency is used as the boundary between low-frequency components and high-frequency components, and can be set according to actual needs. It can be understood that the sum of modal components with a center frequency less than or equal to the preset frequency can be regarded as low-frequency components, as shown in equation (18); and the sum of modal components with a center frequency greater than the preset frequency can be regarded as high-frequency components, as shown in equation (19).

[0154]

[0155]

[0156]

[0157] in, Indicates low-frequency components; Indicates the preset frequency; Indicates high-frequency components; This indicates the AGC power command for a conventional generator set; This indicates the AGC power command for the wind farm energy storage system.

[0158] In one embodiment, the power system may further include multiple wind farm energy storage systems. The wind farm energy storage composite control method for power smoothing and frequency regulation ancillary services further includes steps 600-900.

[0159] Step 600: Based on the current state of charge of multiple wind farm energy storage systems, divide the multiple wind farm energy storage systems into a first sequence and a second sequence.

[0160] The first sequence includes wind farm energy storage systems with a current state of charge (SOC) less than a preset SOC threshold, and the second sequence includes wind farm energy storage systems with a SOC greater than or equal to the preset SOC threshold. For example, the preset SOC threshold can be 0.5.

[0161] For example, multiple wind farm energy storage systems can be numbered in ascending order of their current state of charge:

[0162]

[0163] Where n represents the number of energy storage systems in the wind farm; Indicates the number of the wind farm's energy storage system; This represents the current state of charge of the i-th wind farm energy storage system.

[0164] Step 700: Determine the priority of the first sequence and the second sequence according to the total AGC power command.

[0165] If the total AGC power command indicates that the energy storage system is discharging, then the wind farm energy storage system with SOC > 0.5 has a higher priority; if the total AGC power command indicates that the energy storage system is charging, then the wind farm energy storage system with SOC < 0.5 has a higher priority.

[0166] Step 800: If the total frequency regulation output of the target sequence meets the frequency regulation requirements of the power system, control the energy storage systems of each wind farm in the target sequence to participate in frequency regulation.

[0167] The target sequence is the sequence with higher priority between the first and second sequences.

[0168] Step 900: If the total frequency regulation output of the target sequence does not meet the frequency regulation requirements of the power system, control the energy storage systems of each wind farm in another sequence to participate in frequency regulation.

[0169] It is understandable that after determining the target sequence, the available frequency regulation power of each wind farm energy storage system in the target sequence can be determined based on the aforementioned steps 510-550, and the sum of the available frequency regulation powers can be calculated to obtain the total frequency regulation output of the target sequence. If the total frequency regulation output of the target sequence can meet the frequency regulation requirements of the power system, then only the wind farm energy storage systems in the target sequence need to be controlled to participate in frequency regulation; if the total frequency regulation output of the target sequence does not meet the frequency regulation requirements of the power system, then the wind farm energy storage systems in another sequence can also be controlled to participate in frequency regulation. In this way, while ensuring the state of charge of each wind farm energy storage system, the potential of each wind farm energy storage system to participate in frequency regulation is fully utilized, and the overall benefits of wind farm point energy storage systems in the power system are improved.

[0170] In one embodiment, the frequency regulation output value of the wind farm energy storage system is controlled according to the current wind power, current state of charge, smooth control dead zone and AGC power command, including steps 560-590.

[0171] Step 560: Based on the current wind power, current state of charge, control dead zone, and AGC power command, obtain the available frequency regulation power of each target wind farm energy storage system. The target wind farm energy storage system is the wind farm energy storage system participating in frequency regulation.

[0172] The specific process for obtaining the available frequency regulation power of the energy storage system of each target wind farm can be referred to the description of steps 551-552 above.

[0173] Step 570: Obtain the sum of available frequency regulation power for each target wind farm.

[0174] Step 580: Determine the output weight of the target wind farm energy storage system based on the ratio of each available frequency-modulated power to the sum of available frequency-modulated power, as shown in the following formula:

[0175]

[0176] in, This represents the output weight of the energy storage system in the i-th wind farm.

[0177] Step 590: Control the frequency regulation output value of the corresponding target wind farm energy storage system based on the product of the total AGC power command and the output weight.

[0178] Actual frequency regulation output of wind farm energy storage system It can be represented as:

[0179]

[0180] Total output of wind farm energy storage system It can be represented as:

[0181]

[0182] During the operation of the wind farm energy storage system, its state of charge can be updated according to the total output of the wind farm energy storage system.

[0183]

[0184] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. For example, steps 600 and 700 may be performed before step 400. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they may be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but may be executed at different times. The execution order of these steps or stages is not necessarily sequential, but may be performed alternately or in turn with other steps or at least a portion of the steps or stages of other steps.

[0185] To better illustrate the effect of the wind farm energy storage composite control method for smooth power and frequency regulation auxiliary services provided in this application, a more specific embodiment is given below.

[0186] To meet power demand during power outages, the capacity of the wind farm's energy storage system was set at 4 MWh. AGC signals are sourced from the grid dispatch center and are taken at 1-minute intervals. Historical grid-connected data is also sampled at 1-minute intervals.

[0187] Smoothing out grid-connected power and smoothing out control dead zones, such as Figure 4 .like Figure 4 The curves representing the upper and lower limits of the smoothing control dead zone are shown in the figure. Because the smoothing control dead zone is strongly correlated with past grid-connected power, the smoothing control dead zone varies at each moment. Meanwhile, although the wind farm energy storage system also implements a SOC recovery strategy and AGC frequency regulation control, the energy storage system can still accurately offset the peak power in the wind power, ensuring a relatively stable grid-connected power. Grid-connected power within two evaluation windows is shown in the figure. Figure 5 As shown, the grid connection standards (the solid red lines in the figure) in both evaluation windows can be fully met.

[0188] The allocation of total AGC power commands in the power system is as follows: Figure 6 Using the VMD algorithm, the total AGC power command is decomposed into eight Intrinsic Mode Functions (IMFs) with specific center frequencies and frequency bands. Among them, the low-frequency AGC signals (IMF1 to IMF3) with higher amplitude and smoother fluctuations are assigned to conventional generator sets for response, while the high-frequency AGC signals (IMF4 to IMF8) with lower amplitude but faster fluctuations are similar to the fluctuation characteristics of wind power and are assigned to the wind farm energy storage system for response.

[0189] Figure 7 This demonstrates the AGC power of the energy storage system in the power system before and after a single wind farm energy storage system participates in AGC frequency regulation. Because the energy storage system actively participates in AGC frequency regulation within the smooth control dead zone, part of the total AGC frequency regulation power of the energy storage system in the power system is compensated, reducing the pressure on other energy storage systems focused on frequency regulation, and thus lowering their capacity requirements.

[0190] The power and SOC curves of wind farm energy storage systems under four strategies are as follows: Energy storage systems smooth wind power fluctuations without SOC optimization (e.g., Str-1 curve); Energy storage systems smooth wind power fluctuations with SOC optimization (e.g., Str-2 curve); Energy storage systems participate in composite scenarios without SOC optimization (e.g., Str-3 curve); Energy storage systems participate in composite scenarios with SOC optimization (e.g., Pro-Str curve). Figures 8a-8cAs shown. Due to different control objectives, the power of the energy storage system varies under different control strategies. In scenarios involving energy storage system fluctuation mitigation and participation in combined scenarios, both the energy storage system with a SOC optimization strategy (Str-2) for wind power fluctuation mitigation and the energy storage system participating in combined scenarios with a SOC optimization strategy (Pro-Str) can appropriately reduce the power of the energy storage system to maintain its SOC. Figure 8c It is evident that energy storage systems exhibit significant advantages in mitigating wind power fluctuations with SOC optimization strategies (Str-2) and in energy storage systems participating in composite scenarios with SOC optimization strategies (Pro-Str). In particular, without SOC optimization, the additional energy storage capacity required for wind power will need to be increased (e.g., Figure 8c (The circled part). Meanwhile, compared to the SOC optimization strategy (Str-2) for energy storage systems to smooth wind power fluctuations, there is no significant difference in SOC when energy storage systems participate in composite scenarios with the SOC optimization strategy (Pro-Str). This is because when energy storage systems participate in AGC frequency regulation under the Pro-Str strategy, they need to prioritize the implementation of prescribed SOC optimization control operations. Therefore, the participation of energy storage systems in AGC frequency regulation does not actually affect their SOC optimization.

[0191] Figure 9 The paper demonstrates the AGC power of two wind farm energy storage systems and the total AGC power of wind farm energy storage systems in the power system. When using the control method provided in this application, the AGC frequency regulation potential of the two energy storage systems within the smooth control dead zone is fully exploited, and the combined output of the two energy storage systems is in the same direction, positively impacting the AGC power response. This further reduces the capacity requirements of other energy storage systems in the power system focused on AGC frequency regulation.

[0192] Figure 10 With the participation of multiple wind farm energy storage systems, the total AGC power of wind farm energy storage systems in the power system changes (including peak level and overall level). As the number of wind farm energy storage systems considered increases, the total AGC power of wind farm energy storage systems in the power system gradually decreases. When the number of wind farm energy storage systems increases to a certain extent, the AGC power allocated to the energy storage systems in the power system will be fully compensated, and the capacity of other energy storage systems focused on AGC frequency regulation will be fully released.

[0193] Figure 11a and Figure 11b The power of the energy storage systems in two wind farms recovering their state of charge (SOC) within the smooth control dead zone was demonstrated. Figure 11cThe SOC curves of two energy storage systems within the smooth control dead zone are shown. When using the control method provided in this application, the two energy storage systems can adaptively adjust their output within the smooth control dead zone according to the preset SOC recovery rule to maintain a good SOC level. Furthermore, the energy storage system with the first charging (discharging) priority participates in the AGC charging (discharging) power, so that both systems have a positive effect on the response AGC power and SOC recovery.

[0194] Figure 12 The changes in the overall State of Charge (SOC) involving multiple wind farm energy storage systems are demonstrated. As the number of wind farm energy storage systems considered increases, the overall SOC performance improves, and the wind farm energy storage systems as a whole exhibit better charging and discharging capabilities.

[0195] Based on the same inventive concept, this application also provides a wind farm energy storage composite control device for implementing the wind farm energy storage composite control method for smoothing power and frequency regulation auxiliary services as described above. The solution provided by this device is similar to the solution described in the above method. Therefore, the specific limitations of one or more wind farm energy storage composite control device embodiments for smoothing power and frequency regulation auxiliary services provided below can be found in the limitations of the wind farm energy storage composite control method for smoothing power and frequency regulation auxiliary services described above, and will not be repeated here.

[0196] In one exemplary embodiment, such as Figure 13 As shown, a wind farm energy storage composite control device integrating smooth power and frequency regulation auxiliary services is provided, including: an AGC command acquisition module 1302, a grid connection data acquisition module 1304, a control dead zone determination module 1306, and an output power control module 1308, wherein:

[0197] The AGC instruction acquisition module 1302 is used to acquire the total AGC power instruction of the power system when a power disturbance occurs in the power grid, and to perform mode decomposition processing on the total AGC power instruction to acquire the AGC power instruction of the wind farm energy storage system.

[0198] The grid-connected data acquisition module 1304 is used to acquire the current wind power of the wind turbine, the historical grid-connected power data of the wind farm energy storage system, and the current state of charge.

[0199] The control dead zone determination module 1306 is used to determine the smooth control dead zone of the wind farm energy storage system based on the historical grid-connected power and the current wind power; the smooth control dead zone represents the fluctuation range of the wind farm energy storage system's output while meeting grid connection standards.

[0200] The output power control module 1308 is used to control the smooth output value and frequency regulation output value of the wind farm energy storage system according to the current wind power, current state of charge, smooth control dead zone and AGC power command.

[0201] The modules in the aforementioned wind farm energy storage composite control device for smoothing power and frequency regulation auxiliary services can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the computer device's memory as software, so that the processor can call and execute the corresponding operations of each module.

[0202] In one exemplary embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 14 As shown, the computer device includes a processor, memory, input / output interface, communication interface, display unit, and input device. The processor, memory, and input / output interface are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interface. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The input / output interface is used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, Near Field Communication (NFC), or other technologies. When the computer program is executed by the processor, it implements a wind farm energy storage composite control method that combines smooth power and frequency modulation auxiliary services. The display unit is used to form a visually visible image and can be a display screen, projection device, or virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0203] Those skilled in the art will understand that Figure 14 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0204] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the wind farm energy storage composite control method for smooth power and frequency regulation auxiliary services provided in any of the above embodiments.

[0205] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the wind farm energy storage composite control method for smooth power and frequency modulation auxiliary services provided in any of the above embodiments.

[0206] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the wind farm energy storage composite control method for smooth power and frequency modulation auxiliary services provided in any of the above embodiments.

[0207] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0208] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0209] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A wind farm energy storage composite control method integrating smooth power and frequency regulation auxiliary services, characterized in that, The method is applied to a power system, which includes a power grid, wind turbine generators, and at least one wind farm energy storage system, wherein the wind farm energy storage system is connected to both the wind turbine generators and the power grid; the method includes: In the event of a power disturbance in the power grid, the total AGC power command of the power system is obtained; The total AGC power command is subjected to mode decomposition processing to obtain the AGC power command of the wind farm energy storage system; Acquire the current wind power of the wind turbine, the historical grid-connected power data of the wind farm energy storage system, and the current state of charge. Based on the historical grid-connected power and the current wind power, the smooth control dead zone of the wind farm energy storage system is determined; the smooth control dead zone represents the fluctuation range of the wind farm energy storage system's output while meeting grid connection standards. Based on the current wind power, the current state of charge, the smooth control dead zone, and the AGC power command, the smooth output value and frequency regulation output value of the wind farm energy storage system are controlled respectively.

2. The method according to claim 1, characterized in that, The step of determining the smooth control dead zone of the wind farm energy storage system based on the historical grid-connected power and the current wind power includes: Based on the historical grid-connected power, the first grid-connected power range of the first sub-time period and the second grid-connected power range of the second sub-time period are determined respectively; the duration of the first sub-time period is shorter than the duration of the second sub-time period. Based on the intersection of the first grid-connected power range and the second grid-connected power range, the range of change in the grid-connected power of the wind farm energy storage system at the current moment is determined; The wind power is input into a first-order digital low-pass filter to obtain the initial grid-connected power of the wind farm energy storage system. The smoothing control dead zone is determined based on the difference between the initial grid-connected power and the upper limit of the variation range, and the difference between the initial grid-connected power and the lower limit of the variation range.

3. The method according to claim 1, characterized in that, The step of controlling the smooth output value and frequency regulation output value of the wind farm energy storage system according to the current wind power, the current state of charge, the smooth control dead zone, and the AGC power command includes: The current wind power is input into a first-order digital low-pass filter to obtain the initial grid-connected power of the wind farm energy storage system. The initial smooth output value of the wind farm energy storage system is determined based on the difference between the initial grid-connected power and the current wind power. Based on the initial smoothed output value, the smoothed control dead zone, and the current state of charge, determine the corrected power required for the wind farm energy storage system to restore its state of charge; The smooth output value of the wind farm energy storage system is controlled based on the initial smooth output value and the corrected power. The frequency regulation output value of the wind farm energy storage system is controlled based on the smoothed output value, the current wind power, the smoothed control dead zone, and the AGC power command.

4. The method according to claim 3, characterized in that, The step of controlling the frequency regulation output value of the wind farm energy storage system based on the smoothed output value, the current wind power, the smoothed control dead zone, and the AGC power command includes: The actual grid-connected power of the wind farm energy storage system is determined based on the smoothed output value and the current wind power. The available frequency regulation power of the wind farm energy storage system is determined based on the actual grid-connected power and the smooth control dead zone. The frequency regulation output value of the wind farm energy storage system is controlled based on the smaller value between the available frequency regulation power and the AGC power command.

5. The method according to claim 4, characterized in that, The step of determining the available frequency regulation power of the wind farm energy storage system based on the actual grid-connected power and the smooth control dead zone includes: When the AGC power command indicates that the frequency regulation output of the wind farm energy storage system is reduced, the absolute value of the first difference between the upper limit of the smooth control dead zone and the actual grid-connected power is taken as the available frequency regulation power. When the AGC power command indicates an increase in the frequency regulation output of the wind farm energy storage system, the absolute value of the second difference between the lower limit of the smooth control dead zone and the actual grid-connected power is taken as the available frequency regulation power.

6. The method according to claim 3, characterized in that, The step of determining the corrected power required for the wind farm energy storage system to restore its state of charge based on the initial smoothed output value, the smoothed control dead zone, and the current state of charge includes: When the current state of charge is within the normal range, the corrective power is zero; When the current state of charge is in the primary recovery range and the secondary emergency recovery range, the current state of charge, the upper and lower limits of the smooth control dead zone, and the initial smooth output value are input into a preset Logistic function model to obtain the corrected power. When the current state of charge is in the emergency recovery zone, the corrected power is determined based on the absolute value of the difference between the upper or lower limit of the smooth control dead zone and the initial smooth output value.

7. The method according to claim 1, characterized in that, The step of performing mode decomposition processing on the total AGC power command to obtain the AGC power command of the wind farm energy storage system includes: The total AGC power command is input into a preset variational mode decomposition model to obtain multiple modal components with different center frequencies. The AGC power command is determined based on the sum of modal components whose center frequency is greater than a preset frequency.

8. The method according to any one of claims 1-7, characterized in that, The power system includes multiple wind farm energy storage systems; The method further includes: Based on the current state of charge of the multiple wind farm energy storage systems, the multiple wind farm energy storage systems are divided into a first sequence and a second sequence; the first sequence includes wind farm energy storage systems whose current state of charge is less than a preset state of charge threshold, and the second sequence includes wind farm energy storage systems whose current state of charge is greater than or equal to the preset state of charge threshold. Based on the total AGC power command, determine the priorities of the first sequence and the second sequence; When the total frequency regulation output of the target sequence meets the frequency regulation requirements of the power system, the energy storage systems of each wind farm in the target sequence are controlled to participate in frequency regulation; the target sequence is the sequence with higher priority between the first sequence and the second sequence. If the total frequency regulation output of the target sequence does not meet the frequency regulation requirements of the power system, the energy storage systems of each wind farm in another sequence are controlled to participate in frequency regulation.

9. The method according to claim 8, characterized in that, Based on the current wind power, the current state of charge, the smooth control dead zone, and the AGC power command, the frequency regulation output value of the wind farm energy storage system is controlled, including: Based on the current wind power, the current state of charge, the control dead zone, and the AGC power command, the available frequency regulation power of each target wind farm energy storage system is obtained; the target wind farm energy storage system is the wind farm energy storage system participating in frequency regulation. Obtain the sum of available frequency regulation power for each target wind farm; The output weight of the target wind farm energy storage system is determined based on the ratio of each available frequency-modulated power to the sum of the available frequency-modulated power. The frequency regulation output value of the corresponding target wind farm energy storage system is controlled based on the product of the total AGC power command and the output weight.

10. A wind farm energy storage composite control device for smoothing power and frequency regulation auxiliary services, characterized in that, The device is applied to a power system, which includes a power grid, wind turbine generators, and at least one wind farm energy storage system, wherein the wind farm energy storage system is connected to both the wind turbine generators and the power grid; the device includes: The AGC instruction acquisition module is used to acquire the total AGC power instruction of the power system when the power grid experiences a power disturbance, and to perform mode decomposition processing on the total AGC power instruction to acquire the AGC power instruction of the wind farm energy storage system. The grid-connected data acquisition module is used to acquire the current wind power of the wind turbine, the historical grid-connected power data of the wind farm energy storage system, and the current state of charge. The control dead zone determination module is used to determine the smooth control dead zone of the wind farm energy storage system based on the historical grid-connected power and the current wind power; the smooth control dead zone represents the fluctuation range of the wind farm energy storage system's output while meeting grid connection standards. The output power control module is used to control the smooth output value and frequency regulation output value of the wind farm energy storage system according to the current wind power, the current state of charge, the smooth control dead zone and the AGC power command.

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