A method and system for locating the cause of abnormal primary frequency regulation performance in thermal power units

Abstract

This invention discloses a method and system for locating the causes of abnormal primary frequency regulation performance in thermal power units. The method includes: acquiring the design data and primary frequency regulation operation data of the thermal power unit, calculating the load demand change and the ideal change in turbine flow command; determining whether the unit's energy storage is sufficient based on the turbine flow command and its ideal change; if not, it is an abnormal cause and the operating parameters are adjusted; if so, determining whether the control parameter settings are appropriate based on the ratio of instantaneous to steady-state change in the turbine flow command response curve and the ideal change in turbine flow command; if not, it is an abnormal cause and the control parameters are adjusted; if so, calculating the actual load change based on the unit load response curve and comparing it with the load demand change to determine whether the valve flow characteristic function setting is reasonable; if not, it is an abnormal cause and the function is optimized. This invention improves primary frequency regulation performance by analyzing and locating the main abnormal causes step by step and then optimizing them.

Description

Technical Field

[0001] This invention relates to the operation control technology of thermal power generating units, specifically to a method and system for locating the cause of abnormal primary frequency regulation performance of thermal power generating units. Background Technology

[0002] With the continuous increase in the proportion of new energy installed capacity and the gradual expansion of the scale of non-adjustable power sources in ultra-high voltage transmission, the adverse effects of random fluctuations in new energy output and electricity load on the frequency stability of the power grid are becoming increasingly prominent, and the demand of the power grid for the frequency regulation capability of generator units has increased significantly.

[0003] Primary frequency regulation, as the first line of defense in power system frequency control, refers to the function of generator units to automatically and rapidly adjust active power output to reduce frequency deviation when the system frequency deviates from the target value. It is extremely important for ensuring power system frequency stability. Thermal power units, as the "stabilizer" and "ballast" of the power system, are undeniably crucial to grid frequency stability through their primary frequency regulation performance. However, current thermal power units need to operate for extended periods within a wide load range, especially under deep peak-shaving conditions. Factors such as low main steam pressure and insufficient margin in turbine valve opening lead to insufficient boiler heat storage capacity, making it difficult for their primary frequency regulation performance to meet grid requirements. Furthermore, unreasonable settings of proportional-integral (PI) control parameters in the primary frequency regulation loop, and turbine valve flow functions that do not accurately represent the turbine inlet steam flow characteristics, are also two major factors contributing to abnormal primary frequency regulation performance in thermal power units. It is worth noting that the symptoms of abnormal primary frequency regulation performance in thermal power units caused by insufficient boiler heat storage capacity, unreasonable PI parameter settings, or nonlinearity of turbine valve flow functions are remarkably similar. Therefore, accurately analyzing and precisely locating the causes of abnormal primary frequency regulation performance in thermal power units is crucial for resolving this problem and improving grid frequency stability. Summary of the Invention

[0004] The technical problem to be solved by this invention is that the existing technology lacks a systematic method that can effectively distinguish and accurately locate the root cause of similar performance anomalies, whether it is due to the unit's operating state (energy storage), control logic (PI parameters), or equipment characteristics (valve flow function).

[0005] To address the aforementioned problems in existing technologies, a method and system for locating the causes of abnormal primary frequency regulation performance in thermal power units is provided. By constructing a progressive and causal analysis logic chain, a systematic analysis is conducted on three common factors affecting the primary frequency regulation performance of thermal power units: main operating parameters, control parameters, and valve flow characteristic functions. The main causes of abnormal primary frequency regulation performance are determined step by step, and the operation and control of the thermal power unit are optimized based on the results, thereby improving the primary frequency regulation performance of the thermal power unit.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A method for locating the cause of abnormal primary frequency regulation performance in thermal power units includes the following steps: Acquire the operating data and design data of the thermal power unit during the primary frequency regulation operation; Calculate the load demand change of the thermal power unit based on the operating data and design data. Calculate the ideal change of the turbine flow command based on the operating data, design data, and load demand change. Determine whether the abnormality is due to the unit's energy storage not meeting the load demand change based on the turbine flow command and the ideal change of the turbine flow command in the operating data. If so, adjust the operating data until the unit's energy storage meets the load demand change. If the cause of the anomaly is not that the unit's energy storage does not meet the unit's load demand change, obtain the response curve of the turbine flow command in the operating data, calculate the ratio of the instantaneous change to the steady-state change in the response curve, and determine whether the cause of the anomaly is that the PI control parameters are not set properly based on the ratio and the ideal change of the turbine flow command. If so, adjust the PI control parameters. If the cause of the anomaly is not an inappropriate PI control parameter setting, obtain the unit load response curve from the operating data, calculate the actual load change based on the response curve, and compare the actual load change with the load demand change to determine whether the cause of the anomaly is an unreasonable valve flow characteristic function setting. If so, optimize the valve flow characteristic function.

[0007] Furthermore, the operating data includes frequency deviation, and the design data includes the grid rated frequency and unit speed inequality. When calculating the load demand variation of the thermal power unit based on the operating data and design data, the mathematical expression is as follows:

[0008] in, This refers to the change in unit load demand after the standard unit is established. , f To remove frequency deviation after dead zone removal, f e The rated frequency of the power grid; δ This refers to the unit speed unequal rate.

[0009] Furthermore, the operating data includes the main steam pressure, and the design data includes the rated main steam pressure. When calculating the ideal change in turbine flow command based on the operating data, design data, and load demand changes, the mathematical expression is as follows:

[0010] in, It represents the change in turbine flow command after the per-unit specification. a This refers to the turbine flow command, calculated based on the unit's rated pressure when it is connected to the grid. p and p e These refer to the main steam pressure and rated main steam pressure of the thermal power unit, respectively.

[0011] Furthermore, when determining whether the cause of the anomaly is insufficient unit energy storage to meet the unit load demand change based on the turbine flow command and ideal change in the operating data, specifically, the determination is made based on whether a specified formula holds true. If the specified formula holds true, then the unit energy storage meets the unit load demand change; if the specified formula does not hold true, then the unit energy storage does not meet the unit load demand change, and this is considered an anomaly. The mathematical expression of the specified formula is as follows:

[0012] in, G'=G / 100, G This is a steam turbine flow command.

[0013] Furthermore, when determining whether the anomaly is due to inappropriate PI control parameter settings based on the ratio and the ideal change in turbine flow command, the following steps are taken: The ratio is compared with a specified range, or the product of the ratio and the ideal change in the turbine flow command is calculated to obtain the ideal value of the proportional action coefficient. The actual value of the proportional action coefficient is compared with the ideal value. If the ratio does not fall within the specified range, or the actual value of the proportional action coefficient is less than the ideal value, then the proportional action coefficient of the PI control parameter is not set properly and is an abnormal cause. Compare the steady-state variation of the turbine flow command with the ideal variation of the turbine flow command. If the steady-state variation of the turbine flow command is different from the ideal variation of the turbine flow command, then the integral action parameter setting of the PI control parameter is inappropriate and is an abnormal cause.

[0014] Furthermore, when adjusting the PI control parameters, the following should be considered: If the steady-state variation of the turbine flow command is different from the ideal variation of the turbine flow command, then increase the integral action parameter; If the actual value of the proportionality coefficient is less than the ideal value, then the proportionality coefficient should be increased.

[0015] Furthermore, when comparing the actual load change with the load demand change to determine whether the abnormality is due to an unreasonable setting of the valve flow function characteristic function, specifically, the magnitudes of the actual load change and the load demand change are compared. If the magnitudes of the actual load change and the load demand change are different, then the valve flow function characteristic function setting is unreasonable, and this is the cause of the abnormality.

[0016] Furthermore, adjust the operating data until the unit's energy storage meets the changes in the unit's load demand. Specifically, adjust the main steam pressure or turbine flow command in the operating data. After adjustment, the load demand will be met. Under the condition of varying load demand and minimizing unit throttling losses, the main steam pressure and turbine flow commands satisfy the following formula:

[0017] in, p and These refer to the main steam pressure and turbine flow command after adjusting the main steam pressure or turbine flow command, respectively. a This refers to the turbine flow command, calculated based on the unit's rated pressure when it is connected to the grid. p e The rated main steam pressure of the thermal power unit. It is the change in unit load demand after standardization.

[0018] Furthermore, when optimizing the valve flow characteristic function, specifically, the slope of the actual valve flow characteristic curve at each operating point is adjusted. k The slope of the desired valve flow characteristic curve is 1 / (1- a The deviation direction is used as the optimization guide to optimize the valve flow characteristic function.

[0019] The present invention also proposes a system for locating the cause of abnormal primary frequency regulation performance of thermal power units, including a processor and a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by the processor, it implements the steps of the method for locating the cause of abnormal primary frequency regulation performance of thermal power units.

[0020] The present invention also proposes a computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the steps of the method for locating the cause of abnormal primary frequency regulation performance of thermal power units.

[0021] Compared with the prior art, the advantages of the present invention are as follows: This invention analyzes the three main causes of abnormal primary frequency regulation performance in thermal power units step by step, accurately pinpointing the root cause and facilitating engineering applications. For current thermal power units operating under wide-range load variations, it identifies the flow command that minimizes valve throttling losses while meeting the unit's frequency regulation performance requirements. This guides operators in making optimization adjustments, improving the primary frequency regulation performance and operational economy of thermal power units. Attached Figure Description

[0022] Figure 1 This is a flowchart of a method according to an embodiment of the present invention.

[0023] Figure 2 This illustrates the correspondence between the turbine flow command and the unit load after the rated pressure subscript is 1 in this embodiment of the invention.

[0024] Figure 3 This is a comparison between the ideal valve flow rate and the actual valve flow rate of a thermal power unit in an embodiment of the present invention.

[0025] Figure 4 This is the turbine flow command response trend during a primary frequency regulation operation of a thermal power unit in an embodiment of the present invention. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and specific preferred embodiments, but this does not limit the scope of protection of the present invention.

[0027] Example 1 This embodiment proposes a method for locating the cause of abnormal primary frequency regulation performance in thermal power units, such as... Figure 1 As shown, the method includes the following steps: S101, acquire the operating data and design data of the thermal power unit during the primary frequency regulation operation; S102, calculate the load demand change of the thermal power unit based on the operating data and design data, calculate the ideal change of the turbine flow command based on the operating data, design data and load demand change, and determine whether the abnormality is due to the unit's energy storage not meeting the load demand change based on the turbine flow command and the ideal change of the turbine flow command in the operating data. If so, adjust the operating data until the unit's energy storage meets the load demand change. S103, if the cause of the abnormality is not that the unit's energy storage does not meet the unit's load demand change, obtain the response curve of the turbine flow command in the operating data, calculate the ratio of the instantaneous change to the steady-state change in the response curve, and determine whether the cause of the abnormality is that the PI control parameter is not set properly based on the ratio and the ideal change of the turbine flow command. If so, adjust the PI control parameter. S104. If the cause of the abnormality is not an inappropriate setting of the PI control parameters, obtain the response curve of the unit load in the operating data, calculate the actual load change based on the response curve, and compare the actual load change with the load demand change to determine whether the cause of the abnormality is an unreasonable setting of the valve flow characteristic function. If so, optimize the valve flow characteristic function.

[0028] The above steps utilize operating data and relevant design data from the primary frequency regulation operation of the thermal power unit. By analyzing three main causes—insufficient boiler heat storage capacity, unreasonable PI parameter settings, and nonlinearity of turbine valve flow functions—the causes of abnormal primary frequency regulation performance are accurately located. Simultaneously, based on the results of the cause determination, the operation and control of the thermal power unit are optimized, thereby improving the primary frequency regulation performance of the unit.

[0029] The following is a detailed explanation of each step.

[0030] In this embodiment, the operating data and related design data of the thermal power unit during the primary frequency regulation operation are obtained through step S101. The operating data includes frequency deviation, turbine flow command, unit load, main steam pressure, etc.; the design data includes the unit's rated main steam pressure, rated load, speed unequal rate, grid rated frequency, etc.

[0031] In this embodiment, step S102 calculates the change in unit load demand based on parameters such as frequency deviation, grid rated frequency, unit rated load, and speed inequality, and determines whether the unit's energy storage is sufficient based on parameters such as main steam pressure and turbine flow command. If sufficient, proceed to the next step; otherwise, adjust the unit's main steam pressure, turbine flow command, and other operating parameters to ensure that its energy storage meets the change in load demand. Specifically, this includes the following steps: S201. Calculate the load demand variation of thermal power units based on the frequency deviation in the operating data and the grid rated frequency and unit speed non-discrepancy rate in the design data.

[0032] The unit is at load N During operation, when the grid frequency deviation is f When the per-unit load demand change is, it can be expressed as: (1) in, , N 0 represents the change in unit load demand. N e This is the rated load of the unit; , f To remove frequency deviation after dead zone removal, f eThe rated frequency of the power grid; δ This refers to the generator speed unequal rate, which is typically taken as 4% to 5%.

[0033] S202 calculates the ideal change in turbine flow command based on the main steam pressure in the operating data, the rated main steam pressure in the design data, and the change in load demand.

[0034] The unit load can be approximated as the product of the turbine flow command and the main steam pressure, i.e.: N’ ≈ p’ G’ (2) in, N’ , p’ , G’ These are the unit load, main steam pressure, and turbine flow command after the per-unit specification. N'=N / N e , p'=p / p e , p and p e These are the unit's main steam pressure and rated main steam pressure, respectively. G'=G / 100, G This is a steam turbine flow command.

[0035] If the unit needs to meet The change in load demand is then the change in turbine flow command after per-unit calculation. and The following relationship should be satisfied: (3) in, It represents the change in turbine flow command after the per-unit specification. a This is the converted turbine flow command when the unit is connected to the grid at rated pressure. It is derived from the relationship between the turbine flow command at rated pressure and the unit load. The schematic diagram is shown below. Figure 2 As shown. p and p e These are the main steam pressure and rated main steam pressure of the thermal power unit, respectively. The above formula is based on the linear relationship between the turbine flow command and the unit load at the rated main steam pressure, by introducing... a This maps the current load demand under non-rated operating conditions to the required flow command change under rated pressure, thus providing a unified and comparable benchmark for energy storage judgment under different main steam pressures.

[0036] S203, based on the change between the turbine flow command and the ideal turbine flow command in the operating data, determine whether the abnormality is due to the unit's energy storage not meeting the unit's load demand.

[0037] From equation (3), it can be seen that in order to satisfy Given the change in load demand, the turbine flow command after the per-unit specification should satisfy the following: (4) in, G’ This refers to the turbine flow command after the per-unit specification. It is the change in turbine flow command after the standard unit.

[0038] Equation (4) can be used to determine the load of the unit. N Under the operating conditions, whether the unit energy storage generated by the main steam pressure and turbine flow command meets the unit load demand change is determined. Therefore, in this embodiment, the turbine flow command and the ideal change of the turbine flow command in the operating data are used to determine whether the formula (4) is valid. If the formula (4) is valid, the unit energy storage meets the unit load demand change. If the formula (4) is not valid, the unit energy storage does not meet the unit load demand change and is an abnormal reason. At this time, the main steam pressure and turbine flow command should be adjusted.

[0039] Therefore, in step S102 of this embodiment, adjusting the operating data until the unit's energy storage meets the changes in the unit's load demand specifically involves adjusting the main steam pressure or turbine flow command in the operating data. Given that a larger turbine flow command results in smaller valve throttling losses under the corresponding operating conditions, adjusting the main steam pressure or turbine flow command in the operating data is crucial. To minimize unit throttling losses under the condition of varying load demand, the turbine flow command should be: (5) in, p and These refer to the main steam pressure and turbine flow command after adjusting the main steam pressure or turbine flow command, respectively. a This refers to the turbine flow command, calculated based on the unit's rated pressure when it is connected to the grid. p e The rated main steam pressure of the thermal power unit. It is the change in unit load demand after standardization.

[0040] In step S102 of this embodiment, the main steam pressure and turbine flow command of the unit are adjusted to meet the formula (5), thus eliminating the problem of insufficient energy storage of the unit. For the current thermal power unit, which needs to operate under a wide range of load changes, the flow command that minimizes valve throttling loss is determined under the premise of meeting the frequency regulation performance requirements of the unit. This can guide the operators to make optimization adjustments and improve the primary frequency regulation performance and operating economy of the thermal power unit.

[0041] In this embodiment, step S103 determines whether the PI control parameters in the primary frequency regulation loop are appropriately set based on the change in unit load demand and the response curve of the turbine flow command during primary frequency regulation. If appropriate, proceed to the next step; otherwise, adjust the corresponding PI control parameters so that the turbine flow command response curve meets the control requirements. Specifically, the appropriateness of the PI control parameters is determined based on the trend of turbine flow command changes output by the system in the primary frequency regulation loop. This includes the following steps: S301, for proportional action, is the ratio of the instantaneous change in turbine flow command during a primary frequency regulation operation to its steady-state change. η The ratio is compared with a specified range, which in this embodiment is [0.75, 0.85]. If the ratio does not fall within the specified range, the proportional effect setting of the PI control parameter is inappropriate and is an abnormal reason. In another specific embodiment, for the proportional action, the ideal value of the proportional action coefficient after the per-unit change in turbine flow command obtained from formula (3) can be determined by the following formula: k p0 = G’ η (6) After obtaining the ideal value of the proportional action coefficient by multiplying the ratio and the ideal change in the turbine flow command using formula (6), the actual value of the proportional action coefficient is compared. k p and ideal value k p0 The magnitude of the proportionality coefficient, if the actual value is less than the ideal value ( k p＜ k p0 If the proportional action parameter of the PI control is set incorrectly, it indicates an abnormality. If the actual value of the proportional action coefficient is less than the ideal value, it can be determined that the proportional action in the control loop is weak and should be increased. k p ; S302, for integral action, compare the steady-state change of the turbine flow command output by the system after a frequency regulation action with the ideal change of the turbine flow command calculated by formula (3); if the steady-state change of the turbine flow command is different from the ideal change of the turbine flow command, then the integral action setting of the PI control parameter is inappropriate and is an abnormal cause; when there is a deviation between the steady-state change of the turbine flow command and the ideal change of the turbine flow command, the integral action parameter should be increased; S303, if the proportional action of the PI control parameter is set appropriately (the ratio falls within the specified range, i.e., 0.75) ≤η≤ If the PI control parameters are set appropriately (either the actual value of the proportional action coefficient equals the ideal value) and the integral action is set appropriately (the steady-state change of the turbine flow command is the same as the ideal change of the turbine flow command), then the PI control parameters are set appropriately.

[0042] In step S103 of this embodiment, by analyzing and comparing the changing trend of the turbine flow command output by the system, the proportional and integral actions of the PI control parameters are adjusted to appropriate values, thus eliminating the problem of inappropriate PI control parameter settings. In this embodiment, step S104 determines whether the turbine valve flow function is reasonable based on parameters such as the change in unit load demand, the actual load change, and the turbine flow command. If it is reasonable, the valve flow function problem is eliminated; otherwise, valve flow function optimization needs to be performed. Specifically, this includes: S401, compare the actual load change with the load demand change to determine whether the cause of the anomaly is an unreasonable setting of the valve flow function characteristic function.

[0043] Specifically, when the change in turbine flow command output by the system after a frequency regulation action is the same as the change in turbine flow command obtained from equation (3), the PI control parameters are appropriate, and the actual valve actions are consistent with the valve opening command, then the reasonableness of the set valve flow characteristic function is judged based on the unit load response curve, specifically by comparing the actual load change. N and load demand change N The magnitude of 0 depends on the actual load change of the unit. N ≠ N If the value is 0, then the valve flow characteristic function cannot accurately represent the actual steam flow rate of the unit. The valve flow characteristic function setting is unreasonable and is the cause of the anomaly, requiring optimization of the valve flow characteristic function. Therefore, under the condition that the unit's energy storage and control commands meet the requirements, the only cause of the abnormal primary frequency regulation performance can be deduced from the load deviation as the valve flow characteristic component.

[0044] S402 optimizes the valve flow characteristic function, specifically by adjusting the slope of the actual valve flow characteristic curve at each operating point. k The slope of the desired valve flow characteristic curve is 1 / (1- a The deviation direction is used as the optimization guide to optimize the valve flow characteristic function.

[0045] Specifically, if N < N If the slope is 0, it can be determined that the slope of the actual valve flow characteristic curve at this operating point is smaller than the slope of the expected valve flow characteristic curve, i.e. k <1 / (1- a Conversely, if N > N If it is 0, then it can be determined that... k >1 / (1- a Therefore, the direction of load response deviation can be directly correlated with the slope deviation of the valve flow characteristic function, providing specific guidance for valve flow function optimization.

[0046] The following specific examples illustrate the effectiveness of this implementation method.

[0047] Taking a 1000MW ultra-supercritical thermal power unit as the experimental object, after obtaining the key operating data and relevant design data during primary frequency regulation in step S101, the main steam pressure and turbine flow command of the unit are judged to satisfy equation (4) in step S102. Therefore, the problem of insufficient energy storage of the unit is eliminated, and the next step is taken. Then, in step S103, the trend of the turbine flow command output by the system is analyzed and compared. Its proportional and integral actions are appropriate. Therefore, the problem of inappropriate PI control parameter settings is eliminated, and the next step is taken. In step S104, the ideal valve flow and the actual valve flow of the unit are compared by analyzing the unit's operating data. Figure 3 As shown, the actual load change is determined based on the actual load response curve. N <Changes in unit load demand N 0, that is k <1 / (1- a This indicates that the valve flow characteristic curve exhibits nonlinearity. The analysis based on the above steps reveals that the abnormal primary frequency regulation performance of the unit is caused by an unreasonable valve flow function setting, necessitating optimization of the valve flow characteristic function.

[0048] Taking a 600MW supercritical thermal power unit as the experimental object, after obtaining the key operating data and related design data during primary frequency regulation in step S101, the main steam pressure and turbine flow command of the unit are judged to satisfy equation (4) in step S102. Therefore, the problem of insufficient energy storage of the unit is eliminated, and the next step is taken. In step S103, the turbine flow command response of the unit during primary frequency regulation is as follows: Figure 4 As shown in the figure, the ratio of the instantaneous change in turbine flow command during a single frequency regulation operation to the change in turbine flow command during steady-state operation can be used to obtain... η =0.67. When the turbine flow command changes, the change range is the same as that obtained from equation (3). Therefore, it can be determined that the reason for the abnormal primary frequency regulation performance of the unit is that the proportional action in the control loop is weak. The proportional coefficient needs to be increased to 1.14~1.29 times the original value.

[0049] As can be seen, the method in this embodiment analyzes the three main causes of abnormal primary frequency regulation performance of thermal power units step by step: insufficient unit energy storage, inappropriate control parameter settings, and nonlinearity of turbine valve flow function. This method can accurately locate the cause of abnormal primary frequency regulation performance.

[0050] Example 2 This embodiment proposes a system for locating the cause of abnormal primary frequency regulation performance of thermal power units, including a processor and a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by the processor, it implements the steps of the method for locating the cause of abnormal primary frequency regulation performance of thermal power units described in Embodiment 1.

[0051] This embodiment also proposes a computer-readable storage medium storing a computer program, which is used to be programmed or configured by a microprocessor to execute the method for locating the cause of abnormal primary frequency regulation performance of thermal power units as described in Embodiment 1.

[0052] In summary, this invention discloses a method and system for locating the causes of abnormal primary frequency regulation performance in thermal power units. It analyzes three main causes—insufficient unit energy storage, inappropriate control parameter settings, and nonlinearity of turbine valve flow functions—step by step to accurately pinpoint the cause of the abnormal performance, facilitating engineering applications. For current thermal power units operating under wide-range load variations, this invention determines the flow command that minimizes valve throttling losses while meeting the unit's frequency regulation performance requirements. This guides operators in making optimization adjustments, improving the primary frequency regulation performance and operational economy of thermal power units.

[0053] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-readable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The functions specified in one or more boxes. These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable apparatus for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0054] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for locating the cause of abnormal primary frequency regulation performance in thermal power units, characterized in that, Includes the following steps: Acquire the operating data and design data of the thermal power unit during the primary frequency regulation operation; Calculate the load demand change of the thermal power unit based on the operating data and design data. Calculate the ideal change of the turbine flow command based on the operating data, design data, and load demand change. Determine whether the abnormality is due to the unit's energy storage not meeting the load demand change based on the turbine flow command and the ideal change of the turbine flow command in the operating data. If so, adjust the operating data until the unit's energy storage meets the load demand change. If the cause of the anomaly is not that the unit's energy storage does not meet the unit's load demand change, obtain the response curve of the turbine flow command in the operating data, calculate the ratio of the instantaneous change to the steady-state change in the response curve, and determine whether the cause of the anomaly is that the PI control parameters are not set properly based on the ratio and the ideal change of the turbine flow command. If so, adjust the PI control parameters. If the cause of the anomaly is not an inappropriate PI control parameter setting, obtain the unit load response curve from the operating data, calculate the actual load change based on the response curve, and compare the actual load change with the load demand change to determine whether the cause of the anomaly is an unreasonable valve flow characteristic function setting. If so, optimize the valve flow characteristic function.

2. The method for locating the cause of abnormal primary frequency regulation performance of thermal power units according to claim 1, characterized in that, The operational data includes frequency deviation and main steam pressure, while the design data includes grid rated frequency, unit speed unequal rate, and rated main steam pressure. The mathematical expression for calculating the load demand variation of thermal power units based on the operational and design data is as follows: in, This refers to the change in unit load demand after the standard unit is established. , f To remove frequency deviation after dead zone removal, f e The rated frequency of the power grid; δ The generator unit speed inequality; When calculating the ideal change in turbine flow command based on operating data, design data, and changes in load demand, the mathematical expression is as follows: in, It represents the change in turbine flow command after the per-unit specification. This refers to the change in unit load demand after the standard unit is established. a This refers to the turbine flow command, calculated based on the unit's rated pressure when it is connected to the grid. p and p e These refer to the main steam pressure and rated main steam pressure of the thermal power unit, respectively.

3. The method for locating the cause of abnormal primary frequency regulation performance of thermal power units according to claim 2, characterized in that, When determining whether an anomaly is due to insufficient unit energy storage to meet the unit's load demand changes based on the turbine flow command and ideal change in the operating data, specifically, the determination is made by checking whether a specified formula holds true. If the specified formula holds true, the unit's energy storage meets the unit's load demand changes; if the specified formula does not hold true, the unit's energy storage does not meet the unit's load demand changes, and this is considered an anomaly. The mathematical expression of the specified formula is as follows: in, G'=G / 100, G This is a steam turbine flow command.

4. The method for locating the cause of abnormal primary frequency regulation performance of thermal power units according to claim 1, characterized in that, When determining whether the anomaly is due to inappropriate PI control parameter settings based on the ratio and the ideal change in turbine flow command, the following applies: The ratio is compared with a specified range, or the product of the ratio and the ideal change in the turbine flow command is calculated to obtain the ideal value of the proportional action coefficient. The actual value of the proportional action coefficient is compared with the ideal value. If the ratio does not fall within the specified range, or the actual value of the proportional action coefficient is less than the ideal value, then the proportional action coefficient of the PI control parameter is not set properly and is an abnormal cause. Compare the steady-state variation of the turbine flow command with the ideal variation of the turbine flow command. If the steady-state variation of the turbine flow command is different from the ideal variation of the turbine flow command, then the integral action parameter setting of the PI control parameter is inappropriate and is an abnormal cause.

5. The method for locating the cause of abnormal primary frequency regulation performance of thermal power units according to claim 4, characterized in that, When adjusting PI control parameters, the following should be included: If the steady-state variation of the turbine flow command is different from the ideal variation of the turbine flow command, then increase the integral action parameter; If the actual value of the proportionality coefficient is less than the ideal value, then the proportionality coefficient should be increased.

6. The method for locating the cause of abnormal primary frequency regulation performance of thermal power units according to claim 1, characterized in that, When comparing the actual load change with the load demand change to determine whether the abnormality is due to an unreasonable setting of the valve flow function characteristic function, specifically, the magnitudes of the actual load change and the load demand change are compared. If the magnitudes of the actual load change and the load demand change are different, then the valve flow function characteristic function setting is unreasonable, and this is the cause of the abnormality.

7. The method for locating the cause of abnormal primary frequency regulation performance of thermal power units according to claim 1, characterized in that, Adjust the operating data until the unit's energy storage meets the changes in the unit's load demand. Specifically, adjust the main steam pressure or turbine flow command in the operating data. After adjustment, meet the requirements. Under the condition of varying load demand and minimizing unit throttling losses, the main steam pressure and turbine flow commands satisfy the following formula: in, p and These refer to the main steam pressure and turbine flow command after adjusting the main steam pressure or turbine flow command, respectively. a This refers to the turbine flow command, calculated based on the unit's rated pressure when it is connected to the grid. p e The rated main steam pressure of the thermal power unit. It is the change in unit load demand after standardization.

8. The method for locating the cause of abnormal primary frequency regulation performance of thermal power units according to claim 7, characterized in that, When optimizing the valve flow characteristic function, the specific step is to adjust the slope of the actual valve flow characteristic curve at each operating point. k The slope of the desired valve flow characteristic curve is 1 / (1- a The deviation direction is used as the optimization guide to optimize the valve flow characteristic function.

9. A system for locating the cause of abnormal primary frequency regulation performance in thermal power units, characterized in that, The method includes a processor and a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by the processor, it implements the steps of the method for locating the cause of abnormal primary frequency regulation performance of a thermal power unit as described in any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps of the method for locating the cause of abnormal primary frequency regulation performance of a thermal power unit as described in any one of claims 1 to 8.

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