AGC and primary frequency modulation decoupling control method and device, equipment and storage medium

Abstract

The invention discloses an AGC and primary frequency modulation decoupling control method and device, equipment and a storage medium. The method comprises the following steps: when a frequency value of a power grid deviates from a preset rated value, carrying out primary frequency modulation on the basis of not locking an AGC load instruction; adjusting the response amplitude of the primary frequency modulation according to the primary frequency modulation and the frequency modulation direction of the AGC load instruction; and adjusting the frequency value of the power grid by using the primary frequency modulation after the response amplitude is adjusted. According to the technical scheme, the frequency modulation directions of the AGC and the primary frequency modulation are dynamically judged under the condition that the power grid frequency fluctuates frequently, and the response amplitude of the primary frequency modulation is adaptively adjusted on the basis that an AGC load instruction is not locked. The primary frequency modulation performance under the coupling working condition is improved, the overall performance of AGC and primary frequency modulation is synchronously improved, the response capability of the unit to the power grid frequency change is enhanced, and the comprehensive operation efficiency of the unit is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic control, and in particular to a decoupling control method, device, equipment and storage medium for AGC and primary frequency modulation. Background Art

[0002] In power systems, thermal power units maintain grid frequency stability through two methods: automatic generation control (AGC) and primary frequency regulation. AGC adjusts unit output based on grid dispatch instructions to ensure system frequency and tie-line power stability. Primary frequency regulation involves the unit control system automatically adjusting active power when the grid frequency deviates from the rated value, quickly responding to frequency changes and suppressing frequency fluctuations. For thermal power units, primary frequency regulation is typically implemented by a primary frequency regulation feedforward control loop on the dehumidifier (DEH) side and a primary frequency regulation feedback control loop on the CCS side. The DEH feedforward control loop rapidly adjusts the turbine throttle opening to respond quickly to grid frequency deviations, with minimal delay, ensuring rapid load response. The CCS feedback loop provides precise regulation to compensate for the shortcomings of feedforward control.

[0003] However, for smaller power grids, frequency fluctuations are large, and frequency stability varies significantly. In this situation, thermal power units frequently engage in primary frequency regulation, leading to an increasing number of simultaneous AGC load commands and primary frequency regulation, leading to increasingly severe coupling issues between the two. Traditional methods typically block AGC load commands when primary and AGC frequency regulation directions conflict, prioritizing primary frequency regulation. Frequent blocking of AGC load commands significantly degrades AGC performance. Furthermore, the severe coupling between AGC and primary frequency regulation prevents effective performance assurance for both. According to the assessment requirements of the regional power grid's "Implementation Rules for Grid-Connected Operation Management," a unit's AGC and primary frequency regulation must be independently assessed based on their respective performance indicators. Therefore, when AGC and primary frequency regulation are heavily coupled, existing control strategies struggle to balance their performance, failing to meet grid assessment requirements and impacting the unit's overall performance and economic benefits. Properly addressing these issues has become a pressing issue for the industry. Summary of the Invention

[0004] The present invention provides a decoupling control method, device, equipment and storage medium for AGC and primary frequency modulation, which are used to dynamically determine the frequency modulation direction of AGC and primary frequency modulation when the power grid frequency fluctuates frequently, and adaptively adjust the primary frequency modulation response amplitude, thereby significantly improving the regulation performance of the unit.

[0005] According to a first aspect of the present invention, a decoupling control method for AGC and primary frequency modulation is provided, which is applied to a thermal power generation unit. The decoupling control method for AGC and primary frequency modulation includes:

[0006] When the frequency value of the power grid deviates from the preset rated value, a frequency adjustment is performed without blocking the AGC load instruction;

[0007] adjusting a response amplitude of the primary frequency modulation according to a frequency modulation direction of the primary frequency modulation and the AGC load instruction;

[0008] The frequency value of the power grid is adjusted using the primary frequency modulation after adjusting the response amplitude.

[0009] In one embodiment, it further includes:

[0010] The function of the primary frequency modulation is realized by a feedforward control loop of the primary frequency modulation and a feedback control loop of the primary frequency modulation, wherein the feedforward control loop has the characteristic of rapid adjustment, and the feedback loop has the characteristic of precise adjustment.

[0011] In one embodiment, the frequency value of the power grid deviates from a preset rated value, including:

[0012] The deviation between the frequency value of the power grid and the preset rated value is greater than the prior regulation dead zone, and the unit will perform a frequency regulation action.

[0013] In one embodiment, adjusting the response amplitude of the primary frequency modulation according to the primary frequency modulation and the frequency modulation direction of the AGC compliance instruction includes:

[0014] When the primary frequency regulation is performed, the AGC load instruction does not change, and the primary frequency regulation is performed directly, thereby changing the unit load;

[0015] When the primary frequency modulation is in action, and the frequency modulation directions of the primary frequency modulation and the AGC load instruction are in the same direction, the primary frequency modulation is weakened according to the variable load amplitude of the AGC load instruction;

[0016] When the primary frequency modulation is in effect, the primary frequency modulation and the frequency modulation directions of the AGC load instruction are opposite, and the primary frequency modulation is enhanced according to the variable load amplitude of the AGC load instruction.

[0017] In one embodiment, when the primary frequency modulation is performed, the primary frequency modulation and the frequency modulation direction of the AGC load instruction are in the same direction, and the primary frequency modulation is weakened according to the variable load amplitude of the AGC load instruction, including:

[0018] The feedforward gain of the primary frequency modulation is corrected, and the first correction coefficient is shown in the following formula:

[0019] K1=1-Q a / Q b

[0020] Among them, K1 is the first correction coefficient, Q a It is the real-time calculation of the change of AGC load instruction after rate limitation during a frequency modulation action (i.e. the load variation amplitude of AGC load instruction). b The load variation is calculated based on the frequency difference and the maximum value is memorized during one frequency modulation operation;

[0021] The feedback value of the primary frequency modulation is adjusted, and the first adjustment range is shown in the following formula:

[0022] △Q1=Q b -Q a / 2

[0023] Among them, △Q1 is the first adjustment amplitude, and the above adjustment is performed to avoid the primary frequency modulation response performance exceeding the standard.

[0024] In one embodiment, when the primary frequency modulation is performed, the primary frequency modulation and the frequency modulation directions of the AGC load instruction are opposite, and the primary frequency modulation is enhanced according to the variable load amplitude of the AGC load instruction, including:

[0025] The feedforward gain of the primary frequency modulation is corrected, and the second correction coefficient is shown in the following formula:

[0026] K2=1+Q a / Q b

[0027] Among them, K2 is the second correction coefficient, Q a It is the real-time calculation of the change of AGC load instruction after rate limitation during a frequency modulation action (i.e. the load variation amplitude of AGC load instruction). b The load variation is calculated based on the frequency difference and the maximum value is memorized during one frequency modulation operation;

[0028] The feedback value of the primary frequency modulation is adjusted, and the second adjustment range is shown in the following formula:

[0029] △Q2=Q b +Q a / 2

[0030] Wherein, ΔQ2 is the second adjustment amplitude, and the above adjustment is performed to compensate for the insufficient performance of the primary frequency modulation response.

[0031] According to a second aspect of the present invention, there is provided a decoupling control device for AGC and primary frequency modulation, comprising:

[0032] Compatible module, used to perform frequency regulation without blocking the AGC load instruction when the grid frequency deviates from the preset rated value;

[0033] a frequency modulation module, configured to adjust a response amplitude of the primary frequency modulation according to the primary frequency modulation and the frequency modulation direction of the AGC load instruction;

[0034] The adjustment module is used to adjust the frequency value of the power grid using the primary frequency modulation after adjusting the response amplitude.

[0035] In one embodiment, the compatible module, the frequency modulation module and the adjustment module are controlled to execute any one of the above-mentioned decoupling control methods for AGC and primary frequency modulation.

[0036] According to a third aspect of the present invention, there is provided an electronic device, the electronic device comprising: a communication interface, a processor, and a memory;

[0037] The memory is used to store program instructions, and when the program instructions are executed by the processor that is communicatively connected to the memory through the communication interface, any of the above-mentioned decoupling control methods for AGC and primary frequency modulation is implemented.

[0038] According to a fourth aspect of the present invention, a computer-readable storage medium is provided, on which computer program instructions are stored. When the computer program instructions are executed by a computer (for example, a processor in the computer), any of the above-mentioned decoupling control methods for AGC and primary frequency modulation is implemented.

[0039] In summary, the present invention provides a decoupling control method and device for AGC and primary frequency modulation, the method comprising: when the frequency value of the power grid deviates from the preset rated value, performing primary frequency modulation on the basis of not locking the AGC load instruction; adjusting the response amplitude of the primary frequency modulation according to the frequency modulation direction of the primary frequency modulation and the AGC load instruction; and adjusting the frequency value of the power grid using the primary frequency modulation after adjusting the response amplitude. The technical solution of the present application dynamically judges the frequency modulation direction of AGC and primary frequency modulation when the power grid frequency fluctuates frequently, and adaptively adjusts the primary frequency modulation response amplitude on the basis of not locking the AGC load instruction. It improves the primary frequency modulation performance under the coupled working condition, and simultaneously improves the overall performance of AGC and primary frequency modulation, thereby enhancing the unit's response capability to changes in power grid frequency, and significantly improving the overall operating efficiency of the unit.

[0040] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings.

[0041] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 A flowchart of a decoupling control method for AGC and primary frequency modulation provided by an embodiment of the present invention;

[0044] Figure 2 A schematic diagram of conventional primary frequency modulation control provided by an embodiment of the present invention;

[0045] Figure 3 A schematic diagram of primary frequency modulation control when the primary frequency modulation and AGC are in the same direction according to an embodiment of the present invention;

[0046] Figure 4 A schematic diagram of primary frequency modulation control when the primary frequency modulation and AGC are in the opposite direction according to an embodiment of the present invention;

[0047] Figure 5 A structural diagram of a decoupling control device for AGC and primary frequency modulation provided by an embodiment of the present invention;

[0048] Figure 6 A structural diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is merely to provide a better understanding of the present application by illustrating the examples of the present application.

[0050] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, the elements defined by the phrase "comprising..." do not exclude the presence of other identical elements in the process, method, article, or device comprising the elements.

[0051] Glossary:

[0052] AGC: Automatic generation control refers to the grid dispatching center issuing unit load instructions, and the generator set adjusting the power generation output in real time according to the load instructions to meet the power system frequency and tie line power control requirements.

[0053] Primary frequency regulation: The primary frequency regulation of a generator set refers to the automatic control process in which the control system of the set automatically controls the increase or decrease of the active power of the set when the frequency of the grid deviates from the rated value, limits the change of the grid frequency, and maintains a stable grid frequency.

[0054] like Figure 1 As shown, the present invention provides a decoupling control method for AGC and primary frequency modulation, and the decoupling control method for AGC and primary frequency modulation includes:

[0055] In step S11, when the frequency value of the power grid deviates from the preset rated value, a frequency adjustment is performed without blocking the AGC load instruction;

[0056] In step S12, adjusting the response amplitude of the primary frequency modulation according to the frequency modulation direction of the primary frequency modulation and the AGC load instruction;

[0057] In step S13, the frequency value of the power grid is adjusted using the primary frequency modulation after the response amplitude is adjusted.

[0058] In one embodiment, grid frequency stability is crucial for the reliable operation of modern power systems. Frequency stability is directly related to the normal operation of power equipment and can effectively prevent equipment damage and system failures. Maintaining the grid frequency within a narrow range not only ensures stable equipment operation but also safeguards the overall security of the interconnected power grid, avoiding cascading failures and large-scale power outages. Automatic Generation Control (AGC) and primary frequency regulation are two key mechanisms for achieving and maintaining this stability, especially in thermal power generation units, which occupy a vital position in the power system. Due to their large capacity and sophisticated control systems, thermal power generation units play a vital role in both primary and secondary frequency control of the power grid. Understanding the individual and combined responses of these units is crucial to ensuring the overall stability of the power grid. A novel decoupled control method that addresses the interaction between AGC and primary frequency regulation in thermal power generation units can resolve potential conflicts and improve overall frequency control performance.

[0059] The core working principle of AGC is to automatically adjust the active power output of the generator in response to control signals from the central energy management system (EMS) to maintain the balance between power generation and load. AGC operates in a closed-loop manner, continuously monitoring system conditions and adjusting the output of the generator to minimize deviations from the desired state. The EMS monitors the system frequency and tie-line power flow, calculates the area control error (ACE), and sends signals to the participating generators to increase or decrease their output to restore the ACE to zero. The control cycle of AGC is typically in the range of a few seconds. Depending on the size of the ACE deviation, AGC has different operating modes, such as normal response, auxiliary response, and emergency response. AGC is designed to maintain an acceptable frequency during normal operation and provide early response to system contingencies such as the unexpected loss of generators or transmission lines.

[0060] AGC plays a major role in regulating the frequency of the grid and balancing the supply and demand of electricity on a wider time scale than primary frequency regulation (typically seconds to minutes). While primary frequency regulation provides an immediate response to frequency deviations, the role of AGC is to restore the frequency to its nominal value and maintain the tie-line power flow at the planned level, thereby correcting the steady-state error left by primary frequency regulation. The response time of AGC is a few seconds to keep the system frequency stable. AGC not only serves a stability function, but also plays a role in the economic operation of the power system by selecting the most cost-effective generation units to meet the load demand while maintaining the frequency and tie-line schedule. AGC systems typically contain an economic dispatch algorithm that determines the optimal power output of each participating generator based on its cost characteristics, aiming to minimize the total generation cost while meeting the control objectives.

[0061] The basic operating principle of primary frequency regulation typically relies on the turbine governor's automatic and rapid response to system frequency changes. When a load-generation imbalance occurs, the system frequency changes, and the governors of the individual generators automatically adjust the mechanical power supplied to the turbines (for example, by controlling steam flow in a thermal power plant) to offset this change. The goal of turbine governor control (TGC) is to maintain the desired system frequency. Typical triggering conditions for primary frequency regulation emphasize a "regulatory deadband." Primary frequency regulation typically activates only when the frequency deviation exceeds a preset threshold (deadband) from the nominal value. This deadband prevents the system from making frequent adjustments to minor, normal frequency fluctuations, thereby contributing to system stability and reducing wear on generating equipment. A small deadband ensures that the system responds only to significant frequency deviations requiring corrective action, avoiding continuous adjustments to minor transient fluctuations. The purpose of the deadband is to allow the frequency to remain stable near the nominal value without requiring continuous adjustments to minor fluctuations.

[0062] The regulation rate defines the relationship between frequency changes and corresponding changes in generator power output. Regulation rate control enables the generator to proportionally share the responsibility for responding to frequency deviations, thereby facilitating a stable and coordinated initial response. The regulation characteristic can be asymmetric for over- and under-frequency responses. The steady-state frequency-power relationship of a turbine governor includes a regulation constant that quantifies the generator's sensitivity to frequency changes. Primary frequency regulation prevents frequency drops or rises and provides the necessary time for slower subsequent control measures to take effect. Without effective primary frequency regulation, frequency can deviate rapidly and significantly after a disturbance, potentially leading to load shedding or even system collapse. The rapid response of primary frequency regulation driven by the generator governor is crucial to quickly offset the initial imbalance between generation and load, thereby limiting the rate of change of frequency (ROCOF) and preventing it from reaching critical levels. It provides initial stabilization within seconds to minutes, after which the slower AGC takes over to restore the frequency to its nominal value. Insufficient primary frequency regulation can lead to large frequency deviations.

[0063] In traditional control systems, both AGC and primary frequency regulation respond to frequency deviations, but AGC operates on a slower timescale, aiming to restore the frequency to its nominal value, while primary frequency regulation provides an immediate but often temporary response. Primary frequency regulation reacts to frequency deviations autonomously and locally based on the governor's differential regulation characteristics. AGC, on the other hand, is a centralized control system that monitors the area control error (ACE), which includes frequency deviation and tieline power flow deviations from planned values, and issues commands to generators to adjust their output to reduce the ACE to zero over a longer period of time and restore the system frequency to its nominal value. This difference in response time and control objectives can result in one system potentially counteracting the actions of the other. In conventional control strategies, the interaction between AGC and primary frequency regulation can lead to mutual interference, "shimmy" behavior (oscillations), or conflicting control actions. While the AGC aims to optimize economic dispatch or maintain the tieline schedule, the load commands it sends to generators can counteract the governor's output adjustments in response to frequency deviations, creating a critical conflict. For example, if the primary frequency regulator increases generator output to correct underfrequency, while the AGC simultaneously commands output reduction because the ACE indicates excess generation in that area, this results in a "control action conflict." This can cause system frequency oscillations and reduce the effectiveness of the primary response. To "free up" the governor, the AGC is disabled outside the deadband, negating the AGC's ability to correct frequency.

[0064] The increasing complexity of modern power grids, driven by the growing penetration of variable renewable energy, necessitates more advanced control strategies to ensure seamless coordination between AGC and primary frequency regulation. The intermittent and unpredictable nature of renewable energy sources, such as wind and solar, leads to more frequent and larger deviations in system frequency. Traditional AGC and primary frequency regulation schemes can struggle to effectively handle these rapid fluctuations, potentially leading to increased stress on regulation units and reduced grid stability. In these situations, improved coordination and faster response times become crucial.

[0065] Decoupling control eliminates or minimizes interactions between different control loops in a multivariable system, so that changes in one controlled variable are primarily influenced by its corresponding manipulated variable, with minimal impact on other controlled variables. Decoupling simplifies the control design and operation of complex systems by treating interacting loops as independent or reducing their dependencies. In multivariable systems where multiple inputs influence multiple outputs, interactions between control loops can make it difficult to achieve desired control performance. Decoupling control uses techniques such as feedforward compensation or specialized controller design to counteract these interactions, allowing each control loop to be designed and tuned more independently, ultimately improving stability and performance. The goal of decoupling control is to eliminate complex loop interactions. Decoupling control strategies are often applied to systems with multiple interacting control loops, highlighting the advantages of minimizing interference and achieving more precise and independent control of different process variables. Decoupling control is particularly valuable in complex industrial processes that require simultaneous and independent control of multiple variables, such as chemical reactors, distillation columns, aircraft controls, and power plants. In these applications, manipulating a single input variable often affects multiple output variables, making it difficult to achieve precise control of each output individually. Decoupling control strategies aim to address this issue by designing controllers that compensate for these interactions, ensuring that each manipulated variable primarily affects its intended controlled variable, thereby improving product quality, increasing efficiency, and enhancing safety.

[0066] Applying decoupling control to the specific interactions between AGC and primary frequency regulation in thermal power generation units enables each mechanism to effectively perform its intended function without being negatively impacted or offset by the other, thereby improving overall grid frequency control. By designing a control system in which the actions of primary frequency regulation, which require rapid response to immediate frequency deviations, are less influenced by the slower, more economically oriented AGC instructions, the system can achieve a more robust and optimized response to frequency disturbances and load variations. Decoupling ensures that frequency stability takes priority in the short term while allowing the AGC to manage longer-term balance and economic objectives without interference, ultimately achieving a more stable and reliable grid.

[0067] Conventional approaches might lock the AGC instructions or disable load control to prevent a conflict with the rapid response of the primary frequency modulation. The technical solution in this embodiment proposes a method that allows both to operate simultaneously, allowing the AGC to continue frequency and ACE correction even when the primary frequency modulation response is active. The amplitude of the context-aware primary frequency modulation response is determined not only by the frequency deviation, but also by the goal the AGC is trying to achieve. By modifying the amplitude of the primary frequency modulation response, the rapid response of the primary frequency modulation can handle the initial frequency imbalance while being regulated by the long-term goals of the AGC.

[0068] A feedforward control loop might predict frequency deviations based on AGC commands or other system conditions, enabling a faster initial response from the primary controller. Using the AGC load command as a predictor of future frequency deviations, the feedforward loop can instruct the primary controller to adjust generator output. A feedback control loop might use the actual frequency deviation to provide more accurate and continuous adjustments, ensuring the frequency returns to the desired value. The feedback loop continuously monitors the system frequency and compares it to the nominal value. The error signal is then used to adjust the primary controller's output, ensuring any remaining deviation is corrected and the frequency is restored to the setpoint. Enhanced frequency regulation is achieved through the speed of feedforward and the precision of feedback. Feedforward control handles predictable disturbances and improves initial response, while feedback control compensates for modeling errors and unforeseen disturbances, resulting in better frequency control.

[0069] A regulation deadband is a predefined range around the nominal grid frequency within which the primary frequency regulation system will not initiate any control actions. This deadband prevents the system from making frequent adjustments to minor, normal frequency fluctuations, helping to reduce unnecessary wear on equipment. Small variations in load and generation are inherent to power systems. The deadband filters out these minor deviations, ensuring that the primary frequency regulation system only responds to significant frequency deviations that indicate a true imbalance. The primary frequency regulation system is triggered only when the frequency deviation exceeds the boundaries of this deadband, ensuring that the response is only to meaningful frequency disturbances. By setting an appropriate deadband, the system can avoid overregulation and ensure that the primary frequency regulation system responds to significant frequency deviations that threaten grid stability. The deadband also helps prevent oscillations or repeated activation-deactivation cycles in the control system.

[0070] When primary frequency regulation is activated, the AGC load command remains unchanged. Primary frequency regulation proceeds directly, adjusting the unit load to adjust the grid frequency. If the AGC does not issue a new load command, primary frequency regulation will operate autonomously based solely on the detected frequency deviation to restore the balance between generation and load.

[0071] When the primary frequency modulation is activated, the frequency modulation direction of the primary frequency modulation and the AGC load command are in the same direction. If both mechanisms attempt to adjust the frequency in the same direction, the primary response will be weakened to avoid overshoot or unnecessary large changes. If both the AGC and the primary frequency modulation require increased power generation (for example, during an underfrequency event), the primary response may be reduced to allow the AGC to make finer adjustments over a period of time and prevent the primary frequency modulation from generating an excessive initial response. The feedforward gain of the primary frequency modulation is corrected, and the first correction coefficient is shown in the following formula:

[0072] K1=1-Q a / Q b

[0073] Among them, K1 is the first correction coefficient, Qa It is the real-time calculation of the change of AGC load instruction after rate limitation during a frequency modulation action (i.e. the load variation amplitude of AGC load instruction). b The load change calculated based on the frequency difference is stored in the maximum value during a frequency modulation operation. Subtract this Q from 1. a / Q b This will cause K1 to be less than 1, thereby reducing the feedforward gain of the primary frequency modulation and preventing an overly aggressive response when the two control directions are consistent.

[0074] The feedback value of the primary frequency modulation is adjusted, and the first adjustment range is shown in the following formula:

[0075] △Q1=Q b -Q a / 2

[0076] Among them, △Q1 is the first adjustment range, and the above adjustment is used to avoid the primary frequency modulation response performance from exceeding the standard. When the primary frequency modulation and the AGC frequency modulation directions are the same, a part of the AGC expected load change is subtracted from the expected load change of the primary frequency modulation (Q a / 2) will reduce the feedback adjustment, weaken the response of the primary frequency modulation, and ensure a smoother and more coordinated adjustment.

[0077] By adjusting the feedforward gain and feedback value when the primary frequency modulation and the AGC frequency modulation are in the same direction, a balanced response can be achieved so that both the AGC and the primary frequency modulation can contribute effectively.

[0078] When the primary frequency regulation is activated, the primary frequency regulation and the AGC load command's frequency regulation directions are opposite. The primary frequency regulation's response is enhanced by the magnitude of the change in the AGC load command. The two mechanisms act in opposite directions, thus enhancing the primary response to prioritize immediate frequency correction. If the primary frequency regulation requires increased generation due to underfrequency, but the AGC simultaneously seeks to reduce generation for economic reasons or tie-line regulation, the primary response may be enhanced to ensure frequency stability as the highest priority.

[0079] The feedforward gain of the primary frequency modulation is corrected, and the second correction coefficient is shown in the following formula:

[0080] K2=1+Q a / Q b

[0081] Among them, K2 is the second correction coefficient, Q a It is the real-time calculation of the change of AGC load instruction after rate limitation during a frequency modulation action (i.e. the load variation amplitude of AGC load instruction). bThe load change calculated based on the frequency difference is recorded in the maximum value during a frequency modulation operation. a / Q b It will cause K2 to be greater than 1, thereby enhancing the feedforward gain of the primary frequency modulation and preventing the effect of the primary frequency modulation from being enhanced when the two control directions are opposite.

[0082] The feedback value of the primary frequency modulation is adjusted, and the second adjustment range is shown in the following formula:

[0083] △Q2=Q b +Q a / 2

[0084] Among them, △Q2 is the second adjustment range, which is used to compensate for the insufficient response performance of the primary frequency modulation. When the primary frequency modulation and the AGC frequency modulation directions are opposite, a part of the expected load change of the AGC is added to the expected load change of the primary frequency modulation (Q a / 2) will enhance the feedback adjustment and strengthen the response of the primary frequency modulation, thereby ensuring the effectiveness of the primary frequency modulation.

[0085] According to the regional power grid's assessment requirements, the assessment duration of a primary frequency modulation action is the first minute after the frequency modulation action begins. To prevent prolonged primary frequency modulation from adversely affecting the AGC's regulation performance, if a primary frequency modulation action lasts for more than one minute, the primary frequency modulation's feedforward and feedback functions should be removed, switching the unit from responding simultaneously to AGC and primary frequency modulation to responding only to AGC load regulation. The technical solution in this embodiment is applicable to all thermal power units, especially those in power grids with frequent frequency fluctuations.

[0086] Taking a supercritical coal-fired power generation unit as an example, the primary frequency modulation control function is realized by a feedforward control loop and a feedback control loop. When the unit triggers the primary frequency modulation action during stable operation, the primary frequency modulation instruction is calculated by the primary frequency modulation function corresponding to the turbine speed. This instruction directly acts on the feedback control loop to achieve closed-loop load regulation. At the same time, the primary frequency modulation instruction is converted by the K1 link and superimposed on the turbine control instruction to quickly change the unit load, thereby realizing the feedforward control of the primary frequency modulation. The principle of primary frequency modulation control is shown in the attached figure. Figure 2 shown.

[0087] When the primary frequency modulation and AGC are in the same direction, for example, during the process of AGC increasing the load, if the primary frequency modulation increases the load due to low frequency, or during the process of AGC reducing the load, if the primary frequency modulation reduces the load due to high frequency, the change of the AGC load instruction will not be locked. At the same time, the AGC load instruction change after rate limitation is calculated in real time and defined as the AGC load instruction change. At this time, the control principle of the primary frequency modulation is as shown in the attached figure. Figure 3As shown. Calculate the primary frequency modulation instruction based on the speed deviation, and record the maximum value of the primary frequency modulation instruction during the primary frequency modulation action. Adjust the response amplitude of the primary frequency modulation in real time based on the change in the AGC load instruction and the primary frequency modulation instruction. Correct the feedforward gain of the primary frequency modulation, and the first correction coefficient is shown in the following formula:

[0088] K1=1-Q a / Q b

[0089] Among them, K qk is the first correction coefficient, Q a It is the real-time calculation of the change of AGC load instruction after rate limitation during a frequency modulation action (i.e. the load variation amplitude of AGC load instruction). b The load variation is calculated based on the frequency difference and the maximum value is memorized during one frequency modulation operation;

[0090] The feedback value of the primary frequency modulation is adjusted, and the first adjustment range is shown in the following formula:

[0091] △Q1=Q b -Q a / 2

[0092] Among them, △Q1 is the first adjustment amplitude, and the above adjustment is performed to avoid the primary frequency modulation response performance exceeding the standard.

[0093] When the primary frequency regulation and AGC (automatic generation control) work in opposite directions, for example, during the process of AGC increasing the load, the high frequency triggers the primary frequency regulation to reduce the load, or during the process of AGC reducing the load, the low frequency triggers the primary frequency regulation to increase the load. The change of AGC load instruction will not be locked, allowing it to adjust normally. The calculated load deviation will be sent directly to the steam turbine master control to coordinate the operation of the generator set. According to the variable load amplitude and the primary frequency regulation instruction, the regulating effect of the primary frequency regulation is corrected in real time to ensure the stability of the system frequency. At this time, the control principle of the primary frequency regulation is as shown in the attached figure. Figure 4 The feedforward gain of the primary frequency modulation is corrected, and the second correction coefficient is shown in the following formula:

[0094] K2=1+Q a / Q b

[0095] Among them, K2 is the second correction coefficient, Q a It is the real-time calculation of the change of AGC load instruction after rate limitation during a frequency modulation action (i.e. the load variation amplitude of AGC load instruction). b The load variation is calculated based on the frequency difference and the maximum value is memorized during one frequency modulation operation;

[0096] The feedback value of the primary frequency modulation is adjusted, and the second adjustment range is shown in the following formula:

[0097] △Q2=Q b +Q a / 2

[0098] Wherein, ΔQ2 is the second adjustment amplitude, and the above adjustment is performed to compensate for the insufficient performance of the primary frequency modulation response.

[0099] The technical solution in this embodiment dynamically determines the frequency modulation direction of the AGC and primary frequency modulation when the grid frequency fluctuates frequently, and adaptively adjusts the primary frequency modulation response amplitude without blocking the AGC load command. This improves the primary frequency modulation performance under coupled operating conditions, and simultaneously enhances the overall performance of the AGC and primary frequency modulation, enhancing the unit's responsiveness to grid frequency changes and significantly improving the unit's overall operating efficiency.

[0100] In one embodiment, Figure 5 A block diagram of a decoupling control device for AGC and primary frequency modulation is shown according to an exemplary embodiment. Figure 5 The decoupling control device for AGC and primary frequency modulation includes a compatible module 51 , a frequency modulation module 52 and an adjustment module 53 .

[0101] The compatible module 51 is used to perform a frequency adjustment without blocking the AGC load instruction when the frequency value of the power grid deviates from the preset rated value;

[0102] The frequency modulation module 52 is configured to adjust the response amplitude of the primary frequency modulation according to the frequency modulation direction of the primary frequency modulation and the AGC load instruction;

[0103] The adjustment module 53 is configured to adjust the frequency value of the power grid using the primary frequency modulation after adjusting the response amplitude.

[0104] The compatible module 51, the frequency modulation module 52 and the adjustment module 53 included in the block diagram of the decoupling control device for AGC and primary frequency modulation are controlled to execute the decoupling control method for AGC and primary frequency modulation described in any of the above embodiments.

[0105] like Figure 6 As shown, the present invention provides an electronic device 600, which includes: a communication interface, a processor 601, and a memory 602;

[0106] In which, the memory 602 is used to store program instructions. When the program instructions are executed by the processor 601 that is communicatively connected to the memory 602 through the communication interface, when the frequency value of the power grid deviates from the preset rated value, a primary frequency modulation is performed on the basis of not locking the AGC load instruction; according to the frequency modulation direction of the primary frequency modulation and the AGC load instruction, the response amplitude of the primary frequency modulation is adjusted; and the frequency value of the power grid is adjusted using the primary frequency modulation with the adjusted response amplitude.

[0107] The present invention provides a computer-readable storage medium having computer program instructions stored thereon. When the computer program instructions are executed by a processor, when the frequency value of a power grid deviates from a preset rated value, a primary frequency modulation is performed on the basis of not blocking an AGC load instruction; a response amplitude of the primary frequency modulation is adjusted according to the primary frequency modulation and the frequency modulation direction of the AGC load instruction; and the frequency value of the power grid is adjusted using the primary frequency modulation with the adjusted response amplitude.

[0108] It should be understood that the specific features, operations and details described herein above with respect to the method of the present invention may also be similarly applied to the apparatus and system of the present invention, or vice versa. In addition, each step of the method of the present invention described above may be performed by the corresponding components or units of the apparatus or system of the present invention.

[0109] It should be understood that the various modules / units of the apparatus of the present invention may be implemented in whole or in part by software, hardware, firmware, or a combination thereof. Each module / unit may be embedded in a processor of a computer device in the form of hardware or firmware or may be independent of the processor, or may be stored in a memory of a computer device in the form of software for the processor to call to execute the operations of each module / unit. Each module / unit may be implemented as an independent component or module, or two or more modules / units may be implemented as a single component or module.

[0110] In one embodiment, a computer device is provided, comprising a memory and a processor. The memory stores computer instructions executable by the processor, which, when executed by the processor, instruct the processor to perform the steps of the method according to an embodiment of the present invention. The computer device can be broadly defined as a server, a terminal, or any other electronic device with the necessary computing and / or processing capabilities. In one embodiment, the computer device can include a processor, memory, a network interface, a communication interface, etc. connected via a system bus. The processor of the computer device can be used to provide the necessary computing, processing, and / or control capabilities. The memory of the computer device can include a non-volatile storage medium and an internal memory. An operating system, a computer program, etc. can be stored in or on the non-volatile storage medium. The internal memory can provide an environment for the operation of the operating system and computer program in the non-volatile storage medium. The network interface and communication interface of the computer device can be used to connect to and communicate with external devices via a network. When the computer program is executed by the processor, the steps of the method according to the present invention are performed.

[0111] The present invention can be implemented as a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, causes the steps of the method of an embodiment of the present invention to be performed. In one embodiment, the computer program is distributed on a plurality of computer devices or processors coupled to a network so that the computer program is stored, accessed, and executed in a distributed manner by one or more computer devices or processors. A single method step / operation, or two or more method steps / operations, can be performed by a single computer device or processor or by two or more computer devices or processors. One or more method steps / operations can be performed by one or more computer devices or processors, and one or more other method steps / operations can be performed by one or more other computer devices or processors. One or more computer devices or processors can perform a single method step / operation, or perform two or more method steps / operations.

[0112] It will be understood by those skilled in the art that the method steps of the present invention can be performed by instructing related hardware such as a computer device or a processor through a computer program. The computer program can be stored in a non-transitory computer-readable storage medium, and when the computer program is executed, the steps of the present invention are performed. Depending on the circumstances, any reference to memory, storage, database or other media in this document may include non-volatile and / or volatile memory. Examples of non-volatile memory include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EPROM), flash memory, magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid-state disk, etc. Examples of volatile memory include random access memory (RAM), external cache memory, etc.

[0113] The various technical features described above can be combined arbitrarily. Although not all possible combinations of these technical features are described, any combination of these technical features should be considered to be covered by this specification as long as such combination does not conflict.

[0114] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A decoupling control method for AGC and primary frequency modulation, applied to thermal power generation units, characterized in that: include: When the frequency value of the power grid deviates from the preset rated value, a frequency adjustment is performed without blocking the AGC load instruction; adjusting a response amplitude of the primary frequency modulation according to a frequency modulation direction of the primary frequency modulation and the AGC load instruction; The frequency value of the power grid is adjusted using the primary frequency modulation after adjusting the response amplitude.

2. The decoupling control method of AGC and primary frequency modulation according to claim 1, characterized in that: Also includes: The function of the primary frequency modulation is realized by a feedforward control loop of the primary frequency modulation and a feedback control loop of the primary frequency modulation, wherein the feedforward control loop has the feature of rapid adjustment, and the feedback loop has the feature of precise adjustment.

3. The decoupling control method of AGC and primary frequency modulation according to claim 1, characterized in that: The frequency value of the power grid deviates from a preset rated value, including: The deviation between the frequency value of the power grid and the preset rated value is greater than the prior regulation dead zone, and the unit will perform a frequency regulation action.

4. The decoupling control method of AGC and primary frequency modulation according to claim 2, characterized in that: The adjusting the response amplitude of the primary frequency modulation according to the primary frequency modulation and the frequency modulation direction of the AGC in accordance with the instruction includes: When the primary frequency regulation is performed, the AGC load instruction does not change, and the primary frequency regulation is performed directly, thereby changing the unit load; When the primary frequency modulation is in action, and the frequency modulation directions of the primary frequency modulation and the AGC load instruction are in the same direction, the primary frequency modulation is weakened according to the variable load amplitude of the AGC load instruction; When the primary frequency modulation is in effect, the primary frequency modulation and the frequency modulation directions of the AGC load instruction are opposite, and the primary frequency modulation is enhanced according to the variable load amplitude of the AGC load instruction.

5. The decoupling control method of AGC and primary frequency modulation according to claim 4, characterized in that: When the primary frequency modulation is in effect, the primary frequency modulation and the frequency modulation direction of the AGC load instruction are in the same direction, and the primary frequency modulation is weakened according to the variable load amplitude of the AGC load instruction, including: The feedforward gain of the primary frequency modulation is corrected, and the first correction coefficient is shown in the following formula: K1=1-Q a / Q b Among them, K1 is the first correction coefficient, Q a It is the real-time calculation of the change of AGC load instruction after rate limitation during a frequency modulation action (i.e. the load variation amplitude of AGC load instruction). b The load variation is calculated based on the frequency difference and the maximum value is memorized during one frequency modulation operation; The feedback value of the primary frequency modulation is adjusted, and the first adjustment range is shown in the following formula: △Q1=Q b -Q a / 2 Among them, △Q1 is the first adjustment amplitude, and the above adjustment is performed to avoid the primary frequency modulation response performance exceeding the standard.

6. The decoupling control method of AGC and primary frequency modulation according to claim 4, characterized in that: When the primary frequency modulation is in effect, the primary frequency modulation and the frequency modulation directions of the AGC load instruction are opposite, and the primary frequency modulation is enhanced according to the variable load amplitude of the AGC load instruction, including: The feedforward gain of the primary frequency modulation is corrected, and the second correction coefficient is shown in the following formula: K2=1+Q a / Q b Among them, K2 is the second correction coefficient, Q a It is the real-time calculation of the change of AGC load instruction after rate limitation during a frequency modulation action (i.e. the load variation amplitude of AGC load instruction). b The load variation is calculated based on the frequency difference and the maximum value is memorized during one frequency modulation operation; The feedback value of the primary frequency modulation is adjusted, and the second adjustment range is shown in the following formula: △Q2=Q b +Q a / 2 Wherein, ΔQ2 is the second adjustment amplitude, and the above adjustment is performed to compensate for the insufficient performance of the primary frequency modulation response.

7. A decoupling control device for AGC and primary frequency modulation, applied to thermal power generation units, characterized in that: include: Compatible module, used to perform frequency regulation without blocking the AGC load instruction when the grid frequency deviates from the preset rated value; a frequency modulation module, configured to adjust a response amplitude of the primary frequency modulation according to the primary frequency modulation and the frequency modulation direction of the AGC load instruction; The adjustment module is used to adjust the frequency value of the power grid using the primary frequency modulation after adjusting the response amplitude.

8. The decoupling control device for AGC and primary frequency modulation according to claim 7, characterized in that: The compatible module, the frequency modulation module and the adjustment module are controlled to execute the decoupling control method of AGC and primary frequency modulation according to any one of claims 1 to 6.

9. An electronic device, characterized in that: include: Communication interface, processor, memory; The memory is used to store program instructions, and when the program instructions are executed by the processor that is communicatively connected to the memory through the communication interface, the electronic device implements the decoupling control method of AGC and primary frequency modulation as described in any one of claims 1 to 6.

10. A computer-readable storage medium having program instructions stored thereon, characterized in that: When the program instructions are executed by a computer, the computer implements the decoupling control method of AGC and primary frequency modulation according to any one of claims 1 to 6.

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