Power grid primary frequency modulation control method, device and equipment and readable storage medium

Abstract

A power grid primary frequency modulation control method, device and equipment and readable storage medium, relate to flywheel energy storage frequency modulation technical field, including if current time's power grid frequency deviation exceeds preset frequency modulation dead zone value, generate corresponding primary frequency modulation power instruction of hydroelectric generating set;Based on wavelet packet decomposition technology, the primary frequency modulation power instruction is decomposed to obtain high frequency instruction component and low frequency instruction component;Based on the low frequency instruction component, the actual output power of the hydroelectric generating set is generated;Based on the high frequency instruction component, the power grid frequency deviation, the frequency modulation dead zone value and the real-time state of charge of the flywheel energy storage system, the actual output power of the flywheel energy storage system is generated. Through the application, the effective control of the flywheel energy storage auxiliary hydroelectric generating set participating in the power grid primary frequency modulation can be realized to improve the frequency modulation response speed and regulation accuracy of the hydroelectric generating set.

Description

Technical Field

[0001] This application relates to the field of flywheel energy storage frequency regulation technology, specifically to a power grid primary frequency regulation control method, device, equipment, and readable storage medium. Background Technology

[0002] Under the "dual carbon" goal, the energy structure is undergoing accelerated transformation, with large-scale grid integration of new energy sources. Wind and solar power, in particular, exhibit strong volatility and randomness, placing higher demands on the frequency regulation capabilities of the power system. Currently, primary frequency regulation of the power grid still mainly relies on traditional frequency-regulating power sources, represented by large hydropower units. However, these units suffer from response lag and insufficient accuracy when dealing with rapid and frequent power disturbances, making it difficult to meet the power system's demand for fast and flexible frequency regulation under conditions of high-proportion new energy integration. Flywheel energy storage systems, on the other hand, possess characteristics such as rapid response, precise regulation, and high power density, and have been gradually applied in the field of power grid frequency regulation in recent years.

[0003] However, existing research largely focuses on the coordinated frequency regulation of flywheel energy storage with thermal power units and electrochemical energy storage, while research on how to achieve joint frequency regulation of flywheel energy storage and hydropower units is relatively limited. This has prevented the use of flywheel energy storage systems to effectively overcome the shortcomings of hydropower units in terms of frequency regulation response speed and adjustment flexibility. Therefore, effectively controlling the participation of flywheel energy storage in primary frequency regulation of the power grid with hydropower units to improve the frequency regulation response speed and adjustment accuracy of hydropower units is a pressing issue that needs to be addressed. Summary of the Invention

[0004] This application provides a method, apparatus, equipment, and readable storage medium for primary frequency regulation control of a power grid, which can realize effective control of primary frequency regulation of the power grid involving flywheel energy storage-assisted hydropower units, thereby improving the frequency regulation response speed and regulation accuracy of hydropower units.

[0005] In a first aspect, embodiments of this application provide a primary frequency regulation control method for a power grid, the primary frequency regulation control method comprising: If the current grid frequency deviation exceeds the preset frequency regulation dead zone value, a primary frequency regulation power command corresponding to the hydropower unit is generated. The primary frequency modulation power command is decomposed based on wavelet packet decomposition technology to obtain high-frequency command components and low-frequency command components. The actual output power of the hydroelectric generator is generated based on the low-frequency command components. The actual output power of the flywheel energy storage system is generated based on the high-frequency command component, grid frequency deviation, frequency regulation dead zone value, and the real-time state of charge of the flywheel energy storage system.

[0006] In conjunction with the first aspect, in one implementation, generating the actual output power of the flywheel energy storage system based on the high-frequency command component, grid frequency deviation, frequency modulation dead zone value, and the real-time state of charge of the flywheel energy storage system includes: Regression calculations are performed on the real-time state of charge, the target rated power corresponding to the flywheel energy storage system, the upper limit of the allowable state of charge, and the lower limit of the allowable state of charge to obtain the constraint power limit corresponding to the flywheel energy storage system. The required output power reference value is determined based on the high-frequency command component, grid frequency deviation, frequency modulation dead zone value, real-time state of charge, upper limit of allowable state of charge, lower limit of allowable state of charge, constrained power limit and target rated power. The actual output power of the flywheel energy storage system is generated based on the required output power reference value.

[0007] In conjunction with the first aspect, in one implementation, the frequency modulation dead zone value includes an upper limit and a lower limit, and the step of determining the required output power reference value based on the high-frequency command component, grid frequency deviation, frequency modulation dead zone value, real-time state of charge, upper limit of allowable state of charge, lower limit of allowable state of charge, constrained power limit, and target rated power includes: When the grid frequency deviation is greater than the lower limit of the frequency regulation dead zone and less than the upper limit of the frequency regulation dead zone, the required output power reference value is set to 0. When the grid frequency deviation is less than or equal to the lower limit of the frequency regulation dead zone, the calculation expression for the required output power reference value is as follows:

[0008] When the grid frequency deviation is greater than or equal to the upper limit of the frequency regulation dead zone, the calculation expression for the required output power reference value is as follows:

[0009] In the formula, This indicates the reference value for required output power. Represents high-frequency instruction components. Indicates the target rated power. Indicates the limit of constrained discharge power. This indicates a constraint on charging power limits. Indicates the real-time state of charge. This indicates the upper limit of the permissible state of charge. This indicates the lower limit of the permissible charged state.

[0010] In conjunction with the first aspect, in one embodiment, the method further includes: If the grid frequency deviation does not exceed the frequency regulation dead zone value and the real-time state of charge is outside the preset target SOC range, the target output power is calculated based on the real-time state of charge, the target SOC range, the self-recovery control factor, the grid frequency deviation, and the maximum value of the preset self-recovery control coefficient. The flywheel energy storage system is controlled by the target output power to achieve self-recovery of its state of charge. The self-recovery control factor is determined based on the real-time state of charge, the target SOC range, and the upper and lower limits of the allowable state of charge corresponding to the flywheel energy storage system. The upper limit of the allowable state of charge is greater than the upper limit of the target SOC range, and the lower limit of the allowable state of charge is less than the lower limit of the target SOC range.

[0011] In conjunction with the first aspect, in one implementation, the expression for calculating the target output power is:

[0012] In the formula, Indicates the target output power. This indicates the charging self-recovery control factor. This represents the maximum value of the charging self-recovery control coefficient. This indicates the grid frequency deviation, and SOC indicates the real-time state of charge. This represents the lower limit of the target SOC range. This represents the discharge self-recovery control factor. This represents the maximum value of the discharge self-recovery control coefficient. This represents the upper limit of the target SOC range.

[0013] In conjunction with the first aspect, in one implementation, the calculation expression for the self-recovery control factor is:

[0014]

[0015] In the formula, This indicates the lower limit of the permissible charged state. Indicates the first charging regulation factor. This indicates the upper limit of the permissible state of charge. This represents the first discharge regulation factor.

[0016] In conjunction with the first aspect, in one implementation, the calculation expression for the self-recovery control factor is:

[0017]

[0018]

[0019]

[0020]

[0021]

[0022] In the formula, This indicates the lower limit of the permissible charged state. Indicates the first charging regulation factor. This represents the second charging adjustment factor. This indicates the upper limit of the permissible state of charge. Indicates the first discharge regulation factor. This represents the second discharge regulation factor. , , and All represent the frequency modulation dead zone values ​​and their magnitudes are related as follows: < < < ,in, Greater than the lower limit of the FM dead zone and Less than the upper limit of the FM dead zone.

[0023] Secondly, embodiments of this application provide a primary frequency regulation control device for a power grid, the primary frequency regulation control device comprising: The instruction generation module is used to generate a primary frequency regulation power instruction corresponding to the hydropower unit if the current grid frequency deviation exceeds the preset frequency regulation dead zone value. The instruction decomposition module is used to decompose the primary frequency modulation power instruction based on wavelet packet decomposition technology to obtain high-frequency instruction components and low-frequency instruction components. The frequency control module is used to generate the actual output power of the hydropower unit based on the low-frequency command component; and to generate the actual output power of the flywheel energy storage system based on the high-frequency command component, the grid frequency deviation, the frequency dead zone value, and the real-time state of charge of the flywheel energy storage system.

[0024] In conjunction with the second aspect, in one implementation, the frequency modulation control module is specifically used for: Regression calculations are performed on the real-time state of charge, the target rated power corresponding to the flywheel energy storage system, the upper limit of the allowable state of charge, and the lower limit of the allowable state of charge to obtain the constraint power limit corresponding to the flywheel energy storage system. The required output power reference value is determined based on the high-frequency command component, grid frequency deviation, frequency modulation dead zone value, real-time state of charge, upper limit of allowable state of charge, lower limit of allowable state of charge, constrained power limit and target rated power. The actual output power of the flywheel energy storage system is generated based on the required output power reference value.

[0025] In conjunction with the second aspect, in one embodiment, the frequency modulation dead zone value includes an upper limit value and a lower limit value, and the frequency modulation control module is further configured to: When the grid frequency deviation is greater than the lower limit of the frequency regulation dead zone and less than the upper limit of the frequency regulation dead zone, the required output power reference value is set to 0. When the grid frequency deviation is less than or equal to the lower limit of the frequency regulation dead zone, the calculation expression for the required output power reference value is as follows:

[0026] When the grid frequency deviation is greater than or equal to the upper limit of the frequency regulation dead zone, the calculation expression for the required output power reference value is as follows:

[0027] In the formula, This indicates the reference value for required output power. Represents high-frequency instruction components. Indicates the target rated power. Indicates the limit of constrained discharge power. This indicates a constraint on charging power limits. Indicates the real-time state of charge. This indicates the upper limit of the permissible state of charge. This indicates the lower limit of the permissible charged state.

[0028] In conjunction with the second aspect, in one embodiment, the primary frequency regulation control device for the power grid further includes a SOC self-recovery module, which is used for: If the grid frequency deviation does not exceed the frequency regulation dead zone value and the real-time state of charge is outside the preset target SOC range, the target output power is calculated based on the real-time state of charge, the target SOC range, the self-recovery control factor, the grid frequency deviation, and the maximum value of the preset self-recovery control coefficient. The flywheel energy storage system is controlled by the target output power to achieve self-recovery of its state of charge. The self-recovery control factor is determined based on the real-time state of charge, the target SOC range, and the upper and lower limits of the allowable state of charge corresponding to the flywheel energy storage system. The upper limit of the allowable state of charge is greater than the upper limit of the target SOC range, and the lower limit of the allowable state of charge is less than the lower limit of the target SOC range.

[0029] In conjunction with the second aspect, in one implementation, the expression for calculating the target output power is:

[0030] In the formula, Indicates the target output power. This indicates the charging self-recovery control factor. This represents the maximum value of the charging self-recovery control coefficient. This indicates the grid frequency deviation, and SOC indicates the real-time state of charge. This represents the lower limit of the target SOC range. This represents the discharge self-recovery control factor. This represents the maximum value of the discharge self-recovery control coefficient. This represents the upper limit of the target SOC range.

[0031] In conjunction with the second aspect, in one implementation, the calculation expression for the self-recovery control factor is:

[0032]

[0033] In the formula, This indicates the lower limit of the permissible charged state. Indicates the first charging regulation factor. This indicates the upper limit of the permissible state of charge. This represents the first discharge regulation factor.

[0034] In conjunction with the second aspect, in one implementation, the calculation expression for the self-recovery control factor is:

[0035]

[0036]

[0037]

[0038]

[0039]

[0040] In the formula, This indicates the lower limit of the permissible charged state. Indicates the first charging regulation factor. This represents the second charging adjustment factor. This indicates the upper limit of the permissible state of charge. Indicates the first discharge regulation factor. This represents the second discharge regulation factor. , , and All represent the frequency modulation dead zone values ​​and their magnitudes are related as follows: < < < ,in, Greater than the lower limit of the FM dead zone and Less than the upper limit of the FM dead zone.

[0041] Thirdly, embodiments of this application provide a primary frequency regulation control device for a power grid, the primary frequency regulation control device including a processor, a memory, and a primary frequency regulation control program for a power grid stored in the memory and executable by the processor, wherein when the primary frequency regulation control program for a power grid is executed by the processor, it implements the steps of the aforementioned primary frequency regulation control method for a power grid.

[0042] Fourthly, embodiments of this application provide a computer-readable storage medium storing a primary frequency regulation control program for a power grid, wherein when the primary frequency regulation control program for a power grid is executed by a processor, it implements the steps of the aforementioned primary frequency regulation control method for a power grid.

[0043] The beneficial effects of the technical solutions provided in this application include: This invention generates a primary frequency regulation power command corresponding to the hydropower unit when the grid frequency deviation at the current moment exceeds a preset frequency regulation dead zone value. The primary frequency regulation power command is decomposed using wavelet packet decomposition technology to obtain high-frequency and low-frequency command components. The high-frequency command component is handled by the flywheel energy storage system, while the low-frequency command component is handled by the hydropower unit. Specifically, the actual output power of the hydropower unit is generated based on the low-frequency command component, and the actual output power of the flywheel energy storage system is generated based on the high-frequency command component, grid frequency deviation, frequency regulation dead zone value, and the real-time state of charge of the flywheel energy storage system. Therefore, this application performs multi-scale refined decomposition of the primary frequency regulation power command based on the wavelet packet decomposition principle to obtain high-frequency and low-frequency components. Considering the complementary output characteristics of flywheel energy storage and hydropower units, the high-frequency component is allocated to the flywheel energy storage system and the low-frequency component to the hydropower unit, fully leveraging the frequency regulation advantages of both, thereby improving the frequency regulation response speed and accuracy performance of the hydropower unit and reducing its frequency regulation burden. Attached Figure Description

[0044] Figure 1 This is a flowchart illustrating an embodiment of the power grid primary frequency regulation control method of this application; Figure 2This is a schematic diagram of the structure of the primary frequency regulation frequency response model of the regional power grid involving flywheel energy storage and hydropower units in the embodiments of this application; Figure 3 For this application Figure 1 A detailed flowchart of step S40; Figure 4 This is a functional module diagram of an embodiment of the power grid primary frequency regulation control device of this application; Figure 5 This is a schematic diagram of the hardware structure of the primary frequency regulation control device for the power grid involved in the embodiments of this application. Detailed Implementation

[0045] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0046] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0047] In a first aspect, embodiments of this application provide a method for primary frequency regulation control of a power grid.

[0048] In one embodiment, reference is made to Figure 1 , Figure 1 This is a flowchart illustrating an embodiment of the power grid primary frequency regulation control method of this application. Figure 1 As shown, the primary frequency regulation control method for power grids includes: Step S10: If the current grid frequency deviation exceeds the preset frequency regulation dead zone value, generate a primary frequency regulation power command corresponding to the hydropower unit.

[0049] Exemplary and understandable, the frequency regulation dead zone refers to a permissible range of frequency fluctuation set in the power grid frequency control system. The frequency regulation dead zone value includes an upper limit (i.e., the upper limit of the frequency regulation dead zone) and a lower limit (i.e., the lower limit of the frequency regulation dead zone), the specific values ​​of which can be determined according to actual needs and are not limited here. Power grid frequency deviation refers to the difference between the actual frequency of the power grid and the rated frequency of the power grid, reflecting the dynamic balance of active power supply and demand in the power grid. It can be detected through… Figure 2 The generator-load model shown is directly obtained; the primary frequency regulation power command refers to the power regulation command automatically generated by the power grid system, which is used to drive the hydropower unit to automatically adjust its output in order to restore the stability of the system frequency.

[0050] Based on this, when a load disturbance occurs, once the current grid frequency deviation is detected to exceed the frequency regulation dead zone value, that is, the grid frequency deviation is less than or equal to the lower limit of the frequency regulation dead zone or greater than or equal to the upper limit of the frequency regulation dead zone, it indicates that the imbalance between power generation and load power has exceeded the normal regulation capacity of the system. In other words, the power system supply and demand imbalance has reached the level that requires intervention. In this embodiment, a primary frequency regulation power command corresponding to the hydropower unit will be issued to start frequency regulation control through the primary frequency regulation power command, thereby achieving the purpose of quickly restoring system frequency stability and preventing the safe and stable operation of the system from being threatened.

[0051] Among them, see Figure 2 As shown, the primary frequency regulation power command of the raw hydropower unit Due to power grid frequency deviation The calculation method is as follows:

[0052] In the formula, The droop coefficient of a hydroelectric generator unit represents the proportional relationship between changes in the unit's frequency (speed) and changes in its power output.

[0053] Step S20: Decompose the primary frequency modulation power command based on wavelet packet decomposition technology to obtain high-frequency command components and low-frequency command components.

[0054] Exemplary and understandable, wavelet packet decomposition (WPD) refers to an extended method of wavelet transform that recursively decomposes the low-frequency (approximation coefficients) and high-frequency (detail coefficients) components of a signal through multiple levels, forming a complete binary tree structure. See also Figure 2 As shown, this embodiment will use WPD technology to control the primary frequency modulation power command. Decomposition yields high-frequency command components. and low-frequency command components Specifically, firstly, the primary frequency modulation power command... The signal undergoes n-level wavelet packet decomposition, resulting in 2n sub-signals. The decomposition formula for WPD is as follows:

[0055] In the formula, The specific value of the decomposition level can be determined based on the actual situation and is not limited here. This represents the reconstructed power signal of the wavelet packet at level n-1; , These are the low-frequency and high-frequency coefficients of the nth layer decomposition, respectively; These are the low-pass filter coefficients from wavelet packet decomposition. are the high-pass filter coefficients of wavelet packet decomposition. The specific values ​​of both are determined by the selected wavelet basis function, and the selection of the wavelet basis function can be determined according to actual needs, without limitation here; m is the discrete-time index of the input signal, and r represents the discrete-time index of the output signal.

[0056] set up The low-pass filter coefficients for wavelet packet reconstruction. The high-pass filter coefficients for wavelet packet reconstruction are determined by the selected wavelet basis functions. The formula for reconstructing the nth layer wavelet packet is as follows:

[0057] In the formula, , These are the low-frequency and high-frequency signals reconstructed from the wavelet packet of the nth layer, respectively. , These are the low-frequency coefficients reconstructed at the nth layer, each corresponding to an adjacent sub-band signal belonging to the same parent node. , These are the high-frequency coefficients reconstructed at the nth layer, each corresponding to an adjacent sub-band signal belonging to the same parent node.

[0058] The dividing frequency was determined based on the energy storage of the flywheel and the output characteristics of the hydroelectric generator. and map it to the first Frequency band index of layer wavelet packet decomposition Finally, the high-frequency command components Low-frequency command components allocated to the flywheel energy storage system Assigned to hydropower units:

[0059] In the formula, This represents the time-domain sub-signal corresponding to the m-th frequency band obtained after performing n-level wavelet packet decomposition and frequency band reconstruction on the primary frequency modulation power command signal.

[0060] It should be noted that the specific working methods and principles of WPD are common knowledge in this field, and will not be elaborated here for the sake of brevity.

[0061] Step S30: Generate the actual output power of the hydropower unit based on the low-frequency command component.

[0062] As an example, in this embodiment, the low-frequency command component is allocated to the hydropower unit as the theoretical value of the hydropower unit's required output power, i.e., through the low-frequency command component. The unit power is automatically increased or decreased under the control of the speed regulation system to obtain the actual output power value of the hydropower unit. ; where the actual output power value The specific calculation formula is as follows:

[0063]

[0064] In the formula, s represents the complex frequency variable in the Laplace transform. Represents the transfer function of a hydroelectric generator unit; This represents the equivalent time constant of the speed controller. This represents the equivalent time constant of the turbine and waterway. , This represents the gain parameter, the specific value of which can be determined according to actual needs and is not limited here.

[0065] Step S40: Generate the actual output power of the flywheel energy storage system based on the high-frequency command component, grid frequency deviation, frequency modulation dead zone value, and the real-time state of charge of the flywheel energy storage system.

[0066] Exemplary and understandable, the real-time State of Charge (SOC) represents the amount of electricity currently stored in the flywheel energy storage system; in this embodiment, a high-frequency command component is allocated to the flywheel energy storage system as its required output power value, i.e., see [reference needed]. Figure 2 As shown, the theoretical value of the required output power of flywheel energy storage will be dynamically constrained by high-frequency command components, grid frequency deviation, frequency regulation dead zone value and real-time state of charge, thereby generating the actual output power of the flywheel energy storage system.

[0067] Further, see Figure 3 As shown, the step of generating the actual output power of the flywheel energy storage system based on the high-frequency command component, grid frequency deviation, frequency regulation dead zone value, and the real-time state of charge of the flywheel energy storage system includes: Step S401: Perform regression calculations on the real-time state of charge, the target rated power corresponding to the flywheel energy storage system, the upper limit of the allowable state of charge, and the lower limit of the allowable state of charge to obtain the constraint power limit corresponding to the flywheel energy storage system. Step S402: Determine the required output power reference value based on the high-frequency command component, grid frequency deviation, frequency modulation dead zone value, real-time state of charge, upper limit of allowable state of charge, lower limit of allowable state of charge, constrained power limit and target rated power; Step S403: Generate the actual output power of the flywheel energy storage system based on the required output power reference value.

[0068] As an example, in this embodiment, based on the high-frequency command components and the real-time state of charge of the flywheel energy storage system, and by introducing a Logistic regression function, the theoretical value of the demand output power of the flywheel energy storage is dynamically constrained to obtain a reference value of the demand output power. Then, combined with the external characteristics of the flywheel energy storage's charging and discharging, the actual output power value of the flywheel energy storage system is finally obtained. The constraint function expression based on the modified Logistic regression function is as follows:

[0069] In the formula, , These are the dynamic constraints on the charging and discharging power limits of flywheel energy storage (i.e., the constrained charging power limit and the constrained discharging power limit). This is the rated power value of the flywheel energy storage (i.e., the target rated power); , , , , All of these are constants, and their specific values ​​can be determined according to actual needs, and are not limited here; , These are the upper and lower limits of the allowable state of charge (i.e., the upper limit and lower limit of the allowable state of charge) for the flywheel energy storage system.

[0070] Based on this, assuming the frequency regulation dead zone value of the flywheel energy storage system is By comprehensively considering the theoretical value of the required output power of flywheel energy storage and its state of charge, reference values ​​of its required output power under different operating conditions can be obtained. That is, the required output power reference value is calculated by using high-frequency command components, grid frequency deviation, frequency modulation dead zone value, real-time state of charge, upper limit of allowable state of charge, lower limit of allowable state of charge, constrained power limit, and target rated power. Based on this, the actual output power value of the flywheel energy storage system is finally obtained. for:

[0071]

[0072] In the formula, It is the transfer function of the flywheel energy storage system. Let be the time inertia constant of the flywheel energy storage system.

[0073] Further, in one embodiment, the frequency modulation dead zone value includes an upper limit value and a lower limit value. The step of determining the required output power reference value based on the high-frequency command component, grid frequency deviation, frequency modulation dead zone value, real-time state of charge, upper limit value of allowable state of charge, lower limit value of allowable state of charge, constrained power limit, and target rated power includes: When the grid frequency deviation is greater than the lower limit of the frequency regulation dead zone and less than the upper limit of the frequency regulation dead zone, the required output power reference value is set to 0. When the grid frequency deviation is less than or equal to the lower limit of the frequency regulation dead zone, the calculation expression for the required output power reference value is as follows:

[0074] When the grid frequency deviation is greater than or equal to the upper limit of the frequency regulation dead zone, the calculation expression for the required output power reference value is as follows:

[0075] In the formula, This indicates the reference value for required output power. Represents high-frequency instruction components. Indicates the target rated power. Indicates the limit of constrained discharge power. This indicates a constraint on charging power limits. Indicates the real-time state of charge. This indicates the upper limit of the permissible state of charge. This indicates the lower limit of the permissible charged state.

[0076] As an example, in this embodiment, the required output power reference value under different operating conditions will be determined by the relationship between the grid frequency deviation and the frequency regulation dead zone value. Its specific expression is as follows: (1)

[0077]

[0078] (2)

[0079]

[0080] (3)

[0081]

[0082] in, This indicates the upper limit of the FM dead zone. This indicates the lower limit of the FM dead zone. Represents high-frequency instruction components. Indicates the target rated power. Indicates the limit of constrained discharge power. This indicates a constraint on charging power limits. Indicates the real-time state of charge. This indicates the upper limit of the permissible state of charge. This indicates the lower limit of the permissible charged state.

[0083] Furthermore, in one embodiment, the method further includes: If the grid frequency deviation does not exceed the frequency regulation dead zone value and the real-time state of charge is outside the preset target SOC range, the target output power is calculated based on the real-time state of charge, the target SOC range, the self-recovery control factor, the grid frequency deviation, and the maximum value of the preset self-recovery control coefficient. The flywheel energy storage system is controlled by the target output power to achieve self-recovery of its state of charge. The self-recovery control factor is determined based on the real-time state of charge, the target SOC range, and the upper and lower limits of the allowable state of charge corresponding to the flywheel energy storage system. The upper limit of the allowable state of charge is greater than the upper limit of the target SOC range, and the lower limit of the allowable state of charge is less than the lower limit of the target SOC range.

[0084] Exemplary and understandable, the target SOC range (i.e., the target state of charge range) is used to characterize the current reserved SOC margin available for frequency regulation. That is, if the real-time SOC is within the target SOC range, it indicates that sufficient SOC margin has been reserved for the next frequency regulation; otherwise, it indicates that insufficient SOC margin has not been reserved for the next frequency regulation. The target SOC range is... , and 0 < < < < <1.

[0085] Based on this, when the grid frequency deviation is within the frequency regulation dead zone and the real-time SOC of the flywheel energy storage system is outside the target SOC range (i.e., the grid frequency deviation has not exceeded the frequency regulation dead zone value and the real-time SOC has deviated from the target SOC range), self-recovery control will be implemented for the SOC. That is, the flywheel energy storage system enters the SOC self-recovery mode, gradually restoring the SOC from the target SOC range to its normal value. Within this range, to meet the frequency regulation requirements of the next time; specifically, based on real-time SOC, target SOC range, and the upper limit of allowable state of charge. and the limit value of the permissible state of charge The charge and discharge self-recovery control factor was determined; then, based on this self-recovery control factor and real-time SOC, , , The target output power is calculated from the maximum value of the charge and discharge self-recovery control coefficient. The specific value of the maximum value of the charge and discharge self-recovery control coefficient can be determined according to actual needs and is not limited here; finally, the target output power is achieved. By controlling the output of the flywheel energy storage system, the self-recovery of its state of charge can be achieved. This is understandable. The value is determined by the real-time SOC value and The factors jointly determine that the greater the deviation of the SOC from the target SOC range, the larger the self-recovery control factor, and the greater the magnitude of the self-recovery power. In addition, during the process of the SOC returning to the target SOC range, the self-recovery power gradually decreases until it reaches zero.

[0086] Furthermore, in one embodiment, the calculation expression for the target output power is:

[0087] In the formula, Indicates the target output power. This indicates the charging self-recovery control factor. This represents the maximum value of the charging self-recovery control coefficient. This indicates the grid frequency deviation, and SOC indicates the real-time state of charge. This represents the lower limit of the target SOC range. This represents the discharge self-recovery control factor. This represents the maximum value of the discharge self-recovery control coefficient. This represents the upper limit of the target SOC range.

[0088] As an example, in this embodiment, when the real-time SOC is less than At that time, it will be based on the charging self-recovery control factor. The maximum value of the charging self-recovery control coefficient and grid frequency deviation Calculate the target output power in the charging state. However, if the real-time SOC is greater than At that time, it will be based on the discharge self-recovery control factor The maximum value of the discharge self-recovery control coefficient and power grid frequency deviation Calculate the target output power under discharge conditions. Among them, the target output power The specific calculation formula is as follows:

[0089] It should be noted that, and The specific value can be determined according to actual needs, and is not limited here.

[0090] Furthermore, in one embodiment, the calculation expression for the self-recovery control factor is:

[0091]

[0092] In the formula, This indicates the lower limit of the permissible charged state. Indicates the first charging regulation factor. This indicates the upper limit of the permissible state of charge. This represents the second discharge regulation factor.

[0093] As an example, in this embodiment, the real-time SOC and the allowable state of charge limit can be used. The lower limit of the target SOC range and the upper limit of the target SOC range. and the upper limit of the allowed state of charge The relationship between the magnitudes determines the charging self-recovery control factor. With discharge self-recovery control factor The size of is given by the following formula:

[0094]

[0095] in, Indicates the first charging regulation factor. This represents the first discharge regulation factor; the specific values ​​of both can be determined according to actual needs and are not limited here. It should be noted that, to prevent the grid frequency from exceeding the frequency regulation dead zone during the flywheel energy storage system's self-recovery, the following can be applied: The upper and lower limits can be restricted. Of course, other methods can also be used to control the grid frequency to remain within the frequency regulation dead zone when the flywheel energy storage system self-recovers, which will not be limited here.

[0096] Furthermore, in one embodiment, the calculation expression for the self-recovery control factor is:

[0097]

[0098]

[0099]

[0100]

[0101]

[0102] In the formula, This indicates the lower limit of the permissible charged state. Indicates the first charging regulation factor. This represents the second charging adjustment factor. This indicates the upper limit of the permissible state of charge. Indicates the first discharge regulation factor. This represents the second discharge regulation factor. , , and All represent the frequency modulation dead zone values ​​and their magnitudes are related as follows: < < < ,in, Greater than the lower limit of the FM dead zone and Less than the upper limit of the FM dead zone.

[0103] As an example, in this embodiment, to ensure grid frequency security and prevent the grid frequency from exceeding the frequency regulation dead zone during the flywheel energy storage system's self-recovery, the self-recovery control factor will be limited when the grid frequency deviation is small; specifically, the frequency regulation dead zone value of the flywheel energy storage system will be divided into ascending order as follows: , , , , , , , , , Five intervals, , , and The specific value can be determined according to actual needs, as long as it meets the requirements. < < < < That's it. It should be noted that the FM dead zone value can be divided into more or fewer intervals depending on actual needs; this is not limited here.

[0104] It is worth noting that when This indicates that the grid frequency is approaching the lower limit of the dead zone. To prevent the SOC self-recovery process from further aggravating the frequency deviation, charging self-recovery is not performed; only discharging self-recovery is performed. This indicates that the grid frequency deviation is negative and the amplitude is small, and the grid power is slightly insufficient. Therefore, the discharge self-recovery factor can be large, while the charging self-recovery factor should be small. When this occurs, it indicates a large grid frequency safety margin, allowing the flywheel energy storage system to execute maximum SOC self-recovery control, meaning that both charging and discharging self-recovery factors can reach their maximum values; when This indicates that the frequency deviation is positive and the amplitude is small, and the grid power is relatively abundant. Therefore, the charging self-recovery factor can be large, while the discharging self-recovery factor should be small. This indicates that the grid frequency is approaching the upper limit of the dead zone, and therefore, discharge self-recovery will not be performed; only charging self-recovery will occur. Based on this, the self-recovery control factor is limited as follows:

[0105]

[0106] in, Indicates the first charging regulation factor. This represents the second charging adjustment factor. Indicates the first discharge regulation factor. This represents the second discharge regulation factor, and the specific values ​​of all regulation factors can be determined according to actual needs, without being limited here.

[0107] The final expression for the charge / discharge self-recovery control factor is as follows:

[0108]

[0109]

[0110]

[0111] Thus, by using the aforementioned charge and discharge self-recovery factors for SOC self-recovery control, the grid frequency can be effectively prevented from exceeding the dead zone during the self-recovery of the flywheel energy storage system.

[0112] As can be seen, this embodiment decomposes the primary frequency regulation power command of the power grid into multiple scales using the wavelet packet decomposition principle. The high-frequency command is handled by the flywheel energy storage system, while the low-frequency command is handled by the hydropower unit. This fully leverages the advantages of the flywheel energy storage system, such as fast response speed and high regulation accuracy, effectively compensating for the output lag of the hydropower unit in the initial stage of frequency regulation and reducing mechanical wear caused by frequent adjustments. This significantly improves the overall frequency regulation performance and operational reliability of the system, thereby solving the problems of response lag, load overshoot, and fatigue wear caused by frequent output of traditional hydropower units, ensuring the safe and stable operation of the power grid. Furthermore, considering the maintenance effect of the state of charge (SOC) of the flywheel energy storage system, a regression function is introduced to dynamically correct its output power command, avoiding overcharging and over-discharging. In addition, when the grid frequency difference is within the frequency regulation dead zone, a SOC correction and self-recovery mechanism is introduced to achieve self-recovery of the flywheel energy storage SOC. This allows the flywheel energy storage SOC to return to a healthy state without disrupting the normal operation of the power grid, ensuring that the flywheel energy storage system can effectively maintain its SOC during frequent frequency regulation and reserving sufficient margin for its next rapid participation in frequency regulation.

[0113] In summary, this embodiment proposes a control method for flywheel energy storage to assist hydropower units in participating in the primary frequency regulation of the power grid. The aim is to fully leverage the rapid response and precise regulation characteristics of the flywheel energy storage system, compensate for the shortcomings of hydropower units in frequency regulation response speed and regulation flexibility, and achieve complementary advantages of the two in frequency regulation. This effectively improves the dynamic response performance of hydropower units and has important engineering application value and promotion significance for ensuring the safe and stable operation of the power grid under the condition of high proportion of new energy access.

[0114] Secondly, embodiments of this application also provide a power grid primary frequency regulation control device.

[0115] In one embodiment, reference is made to Figure 4 , Figure 4 This is a functional module diagram of an embodiment of the power grid primary frequency regulation control device of this application. Figure 4 As shown, the primary frequency regulation control device for the power grid includes: The instruction generation module is used to generate a primary frequency regulation power instruction corresponding to the hydropower unit if the current grid frequency deviation exceeds the preset frequency regulation dead zone value. The instruction decomposition module is used to decompose the primary frequency modulation power instruction based on wavelet packet decomposition technology to obtain high-frequency instruction components and low-frequency instruction components. The frequency control module is used to generate the actual output power of the hydropower unit based on the low-frequency command component; and to generate the actual output power of the flywheel energy storage system based on the high-frequency command component, the grid frequency deviation, the frequency dead zone value, and the real-time state of charge of the flywheel energy storage system.

[0116] Furthermore, in one embodiment, the frequency modulation control module is specifically used for: Regression calculations are performed on the real-time state of charge, the target rated power corresponding to the flywheel energy storage system, the upper limit of the allowable state of charge, and the lower limit of the allowable state of charge to obtain the constraint power limit corresponding to the flywheel energy storage system. The required output power reference value is determined based on the high-frequency command component, grid frequency deviation, frequency modulation dead zone value, real-time state of charge, upper limit of allowable state of charge, lower limit of allowable state of charge, constrained power limit and target rated power. The actual output power of the flywheel energy storage system is generated based on the required output power reference value.

[0117] Furthermore, in one embodiment, the frequency modulation dead zone value includes an upper limit value and a lower limit value, and the frequency modulation control module is further used for: When the grid frequency deviation is greater than the lower limit of the frequency regulation dead zone and less than the upper limit of the frequency regulation dead zone, the required output power reference value is set to 0. When the grid frequency deviation is less than or equal to the lower limit of the frequency regulation dead zone, the calculation expression for the required output power reference value is as follows:

[0118] When the grid frequency deviation is greater than or equal to the upper limit of the frequency regulation dead zone, the calculation expression for the required output power reference value is as follows:

[0119] In the formula, This indicates the reference value for required output power. Represents high-frequency instruction components. Indicates the target rated power. Indicates the limit of constrained discharge power. This indicates a constraint on charging power limits. Indicates the real-time state of charge. This indicates the upper limit of the permissible state of charge. This indicates the lower limit of the permissible charged state.

[0120] Furthermore, in one embodiment, the primary frequency regulation control device of the power grid further includes a SOC self-recovery module, which is used for: If the grid frequency deviation does not exceed the frequency regulation dead zone value and the real-time state of charge is outside the preset target SOC range, the target output power is calculated based on the real-time state of charge, the target SOC range, the self-recovery control factor, the grid frequency deviation, and the maximum value of the preset self-recovery control coefficient. The flywheel energy storage system is controlled by the target output power to achieve self-recovery of its state of charge. The self-recovery control factor is determined based on the real-time state of charge, the target SOC range, and the upper and lower limits of the allowable state of charge corresponding to the flywheel energy storage system. The upper limit of the allowable state of charge is greater than the upper limit of the target SOC range, and the lower limit of the allowable state of charge is less than the lower limit of the target SOC range.

[0121] Furthermore, in one embodiment, the calculation expression for the target output power is:

[0122] In the formula, Indicates the target output power. This indicates the charging self-recovery control factor. This represents the maximum value of the charging self-recovery control coefficient. This indicates the grid frequency deviation, and SOC indicates the real-time state of charge. This represents the lower limit of the target SOC range. This represents the discharge self-recovery control factor. This represents the maximum value of the discharge self-recovery control coefficient. This represents the upper limit of the target SOC range.

[0123] Furthermore, in one embodiment, the calculation expression for the self-recovery control factor is:

[0124]

[0125] In the formula, This indicates the lower limit of the permissible charged state. Indicates the first charging regulation factor. This indicates the upper limit of the permissible state of charge. This represents the first discharge regulation factor.

[0126] Furthermore, in one embodiment, the calculation expression for the self-recovery control factor is:

[0127]

[0128]

[0129]

[0130]

[0131]

[0132] In the formula, This indicates the lower limit of the permissible charged state. Indicates the first charging regulation factor. This represents the second charging adjustment factor. This indicates the upper limit of the permissible state of charge. Indicates the first discharge regulation factor. This represents the second discharge regulation factor. , , and All represent the frequency modulation dead zone values ​​and their magnitudes are related as follows: < < < ,in, Greater than the lower limit of the FM dead zone and Less than the upper limit of the FM dead zone.

[0133] The functions of each module in the aforementioned primary frequency regulation control device correspond to the steps in the aforementioned primary frequency regulation control method embodiment, and their functions and implementation processes will not be described in detail here.

[0134] Thirdly, embodiments of this application provide a power grid primary frequency regulation control device, which can be a personal computer (PC), laptop computer, server, or other device with data processing capabilities.

[0135] Reference Figure 5 , Figure 5 This is a schematic diagram of the hardware structure of the primary frequency regulation control device for a power grid involved in the embodiments of this application. In the embodiments of this application, the primary frequency regulation control device for a power grid may include a processor, a memory, a communication interface, and a communication bus.

[0136] The communication bus can be of any type and is used to interconnect the processor, memory, and communication interface.

[0137] Communication interfaces include input / output (I / O) interfaces, physical interfaces, and logical interfaces used for interconnecting devices within the primary frequency regulation control equipment of the power grid, as well as interfaces used for interconnecting the primary frequency regulation control equipment of the power grid with other devices (such as other computing devices or user equipment). Physical interfaces can be Ethernet interfaces, fiber optic interfaces, ATM interfaces, etc.; user equipment can be displays, keyboards, etc.

[0138] Memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0139] The processor can be a general-purpose processor, which can call the primary frequency regulation control program of the power grid stored in the memory and execute the primary frequency regulation control method of the power grid provided in the embodiments of this application. For example, the general-purpose processor can be a central processing unit (CPU). The method executed when the primary frequency regulation control program of the power grid is called can be referred to in the various embodiments of the primary frequency regulation control method of the power grid in this application, and will not be described again here.

[0140] Those skilled in the art will understand that Figure 5 The hardware structure shown does not constitute a limitation of this application and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0141] Fourthly, embodiments of this application also provide a computer-readable storage medium.

[0142] The present application has a readable storage medium storing a power grid primary frequency regulation control program, wherein when the power grid primary frequency regulation control program is executed by a processor, it implements the steps of the power grid primary frequency regulation control method as described above.

[0143] The method implemented when the primary frequency regulation control program of the power grid is executed can be referred to in various embodiments of the primary frequency regulation control method of the power grid in this application, and will not be repeated here.

[0144] It should be noted that the sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0145] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus. The terms "first," "second," and "third," etc., are used to distinguish different objects, etc., and do not indicate a sequence, nor do they limit "first," "second," and "third" to different types.

[0146] In the description of the embodiments of this application, terms such as "exemplary," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a concrete manner.

[0147] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.

[0148] In some processes described in the embodiments of this application, multiple operations or steps are included in a specific order. However, it should be understood that these operations or steps may not be executed in the order they appear in the embodiments of this application, or they may be executed in parallel. The sequence number of the operation is only used to distinguish the different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed sequentially or in parallel, and these operations or steps may be combined.

[0149] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device to execute the methods described in the various embodiments of this application.

[0150] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A method for primary frequency regulation control of a power grid, characterized in that, The primary frequency regulation control method for the power grid includes: If the current grid frequency deviation exceeds the preset frequency regulation dead zone value, a primary frequency regulation power command corresponding to the hydropower unit is generated. The primary frequency modulation power command is decomposed based on wavelet packet decomposition technology to obtain high-frequency command components and low-frequency command components. The actual output power of the hydroelectric generator is generated based on the low-frequency command components. The actual output power of the flywheel energy storage system is generated based on the high-frequency command component, grid frequency deviation, frequency regulation dead zone value, and the real-time state of charge of the flywheel energy storage system.

2. The power grid primary frequency regulation control method as described in claim 1, characterized in that, The process of generating the actual output power of the flywheel energy storage system based on the high-frequency command component, grid frequency deviation, frequency regulation dead zone value, and the real-time state of charge of the flywheel energy storage system includes: Regression calculations are performed on the real-time state of charge, the target rated power corresponding to the flywheel energy storage system, the upper limit of the allowable state of charge, and the lower limit of the allowable state of charge to obtain the constraint power limit corresponding to the flywheel energy storage system. The required output power reference value is determined based on the high-frequency command component, grid frequency deviation, frequency modulation dead zone value, real-time state of charge, upper limit of allowable state of charge, lower limit of allowable state of charge, constrained power limit and target rated power. The actual output power of the flywheel energy storage system is generated based on the required output power reference value.

3. The power grid primary frequency regulation control method as described in claim 2, characterized in that, The frequency modulation dead zone value includes an upper limit and a lower limit. The determination of the required output power reference value based on the high-frequency command component, grid frequency deviation, frequency modulation dead zone value, real-time state of charge, upper limit of allowable state of charge, lower limit of allowable state of charge, constrained power limit, and target rated power includes: When the grid frequency deviation is greater than the lower limit of the frequency regulation dead zone and less than the upper limit of the frequency regulation dead zone, the required output power reference value is set to 0. When the grid frequency deviation is less than or equal to the lower limit of the frequency regulation dead zone, the calculation expression for the required output power reference value is as follows: When the grid frequency deviation is greater than or equal to the upper limit of the frequency regulation dead zone, the calculation expression for the required output power reference value is as follows: In the formula, This indicates the reference value for required output power. Represents high-frequency instruction components. Indicates the target rated power. Indicates the limit of constrained discharge power. This indicates a constraint on charging power limits. Indicates the real-time state of charge. This indicates the upper limit of the permissible state of charge. This indicates the lower limit of the permissible charged state.

4. The power grid primary frequency regulation control method as described in claim 1, characterized in that, The method further includes: If the grid frequency deviation does not exceed the frequency regulation dead zone value and the real-time state of charge is outside the preset target SOC range, the target output power is calculated based on the real-time state of charge, the target SOC range, the self-recovery control factor, the grid frequency deviation, and the maximum value of the preset self-recovery control coefficient. The flywheel energy storage system is controlled by the target output power to achieve self-recovery of its state of charge. The self-recovery control factor is determined based on the real-time state of charge, the target SOC range, and the upper and lower limits of the allowable state of charge corresponding to the flywheel energy storage system. The upper limit of the allowable state of charge is greater than the upper limit of the target SOC range, and the lower limit of the allowable state of charge is less than the lower limit of the target SOC range.

5. The power grid primary frequency regulation control method as described in claim 4, characterized in that, The expression for calculating the target output power is: In the formula, Indicates the target output power. This indicates the charging self-recovery control factor. This represents the maximum value of the charging self-recovery control coefficient. This indicates the grid frequency deviation, and SOC indicates the real-time state of charge. This represents the lower limit of the target SOC range. This represents the discharge self-recovery control factor. This represents the maximum value of the discharge self-recovery control coefficient. This represents the upper limit of the target SOC range.

6. The power grid primary frequency regulation control method as described in claim 5, characterized in that, The calculation expression for the self-recovery control factor is as follows: In the formula, This indicates the lower limit of the permissible charged state. Indicates the first charging regulation factor. This indicates the upper limit of the permissible state of charge. This represents the first discharge regulation factor.

7. The power grid primary frequency regulation control method as described in claim 5, characterized in that, The calculation expression for the self-recovery control factor is as follows: In the formula, This indicates the lower limit of the permissible charged state. Indicates the first charging regulation factor. This represents the second charging adjustment factor. This indicates the upper limit of the permissible state of charge. Indicates the first discharge regulation factor. This represents the second discharge regulation factor. , , and All represent the frequency modulation dead zone values ​​and their magnitudes are related as follows: < < < ,in, Greater than the lower limit of the FM dead zone and Less than the upper limit of the FM dead zone.

8. A primary frequency regulation control device for a power grid, characterized in that, The primary frequency regulation control device for the power grid includes: The instruction generation module is used to generate a primary frequency regulation power instruction corresponding to the hydropower unit if the current grid frequency deviation exceeds the preset frequency regulation dead zone value. The instruction decomposition module is used to decompose the primary frequency modulation power instruction based on wavelet packet decomposition technology to obtain high-frequency instruction components and low-frequency instruction components. The frequency control module is used to generate the actual output power of the hydropower unit based on the low-frequency command component; and to generate the actual output power of the flywheel energy storage system based on the high-frequency command component, the grid frequency deviation, the frequency dead zone value, and the real-time state of charge of the flywheel energy storage system.

9. A primary frequency regulation control device for a power grid, characterized in that, The power grid primary frequency regulation control device includes a processor, a memory, and a power grid primary frequency regulation control program stored in the memory and executable by the processor, wherein when the power grid primary frequency regulation control program is executed by the processor, it implements the steps of the power grid primary frequency regulation control method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a primary frequency regulation control program for a power grid, wherein when the primary frequency regulation control program for a power grid is executed by a processor, it implements the steps of the primary frequency regulation control method for a power grid as described in any one of claims 1 to 7.

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