AGC instruction step size capturing method

Abstract

The invention relates to the field of automatic power generation control, and discloses an AGC instruction step size grabbing method, which comprises the following steps: dispatching and sending an AGC instruction, transmitting the AGC instruction to a DCS (Distributed Control System) of a power plant through an RTU (Remote Terminal Unit), carrying out auxiliary frequency modulation control on part of the power plant by adopting a PLC (Programmable Logic Controller) plug-in system, and realizing data interaction between part of the DCS and a PLC through an interface machine; and recording the AGC instruction value # imgabs0 # corresponding to each sampling time point (tn) so as to determine the starting and ending time of the AGC instruction. According to the invention, the starting and ending time of the AGC instruction can be automatically positioned, scheduled and sent, the step length of the AGC instruction can be intelligently grabbed, manual intervention is not needed, a time monitoring window delta t and a monitoring load instruction delta P can be flexibly adjusted, a monitoring value can be set according to the actual transmission condition of the AGC instruction of a unit and equipment, and the AGC instruction data transmission link abnormity alarm is realized. According to the delay characteristic of the unit AGC instruction, a proper alarm threshold can be selected, the plug-in can be quitted in time, and the difficulty in tracking and adjusting the unit load is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of automatic power generation control, and in particular to an AGC instruction step length capture method. Background Art

[0002] AGC instruction: The AGC instruction is part of the Automatic Generation Control, which aims to meet the frequency and power requirements of the power system by adjusting the output of the generator set. The main goal of the AGC instruction is to maintain the deviation of the system frequency from the rated value within the allowable range, and to maintain the deviation of the net exchange power of the external interconnection line from the planned value within the allowable range. In actual applications, the AGC instruction is issued through the dispatching automation system, requiring the generator set to adjust its output according to the instruction. This process involves real-time monitoring and adjustment of the generator sets in the region to ensure the real-time balance of power supply and demand. Provincial dispatching automation systems usually have AGC functions. By implementing AGC instructions, high-quality power supply can be obtained, real-time balance of power supply and demand can be achieved, and the labor intensity of operation and management personnel can be reduced. Step size: The single adjustment amplitude of the AGC instruction.

[0003] Under the new situation, the power grid's requirements for the response time of each unit to the AGC command (i.e., the AGC response rate) are constantly increasing. Due to the long heat release inertia time of the coal-fired power unit boiler, fuel must be added or subtracted in advance to increase the unit's load change rate. AGC command step monitoring is the key to predicting the system's power demand and boiler output in advance. In order to adapt to the requirements of the new frequency regulation files, various power plants have successively installed frequency regulation external equipment to increase the unit's load change rate in order to obtain frequency regulation auxiliary service mileage compensation. AGC commands have more transmission links and longer paths than before, and are prone to signal delays and distortions, which makes it more difficult to capture the AGC command step.

[0004] However, at present, several methods for obtaining the step size of the dispatching AGC command have the following defects: Relying on the planned curve to obtain: At present, the usual way to obtain the step size of the unit AGC command is based on the daily load plan curve issued by the power grid dispatch (1 set value every 5 minutes or every 15 minutes); Due to the continuous and rapid increase in the amount of new energy connected to the grid, the load demand of the power grid is complex and changeable and difficult to predict, and the actual unit output demand often deviates greatly from the planned curve. Calculate the step size by the difference before and after the AGC command changes: Due to the many transmission links and long paths of the AGC command, the single AGC step command received by the DCS or external terminal is easily distorted into multiple step commands or ramps and other complex signals. This method is easy to capture the wrong deformed AGC command step size, reducing the regulation performance of the unit. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides an AGC instruction step capture method, which solves the problem that the prior method is prone to capture erroneous deformed AGC instruction step lengths, thereby reducing the regulating performance of the unit.

[0006] To achieve the above objectives, the present invention is implemented by the following technical solutions: a method for capturing the step length of an AGC instruction, comprising the following steps:

[0007] S1: The dispatcher sends the AGC command, which is transmitted to the DCS system of the power plant through the power remote terminal control system RTU. Some power plants use PLC plug-in systems for auxiliary frequency control, and some DCS require an interface machine to realize data interaction with PLC;

[0008] S2: Record each sampling time point (t n ) corresponding to the AGC command value To determine the start and end time of the AGC instruction;

[0009] S3: Set the time monitoring window (Δt), during which the minimum change of the monitoring load command should not be less than the monitoring load command (ΔP);

[0010] S4: Use the time monitoring window to mark the transmission start and end time of the AGC instruction, specifically:

[0011] when When , it is determined that the dispatching variable load AGC instruction starts to be received;

[0012] when When , it is determined that the receiving of the dispatching variable load AGC instruction is completed;

[0013] S5: Determine whether the AGC instruction transmission is normal by comparing (t n2 -t n1 ) and the predetermined time (ΔT), if (t n2 -t n1 <ΔT), it indicates that the AGC instruction is transmitted within the scheduled time and the data transmission link is normal; otherwise, it indicates that the AGC instruction data transmission link of the plug-in system is abnormal;

[0014] S6: If the data transmission link is normal, calculate the AGC instruction step length And automatically reset the AGC instruction step capture control loop.

[0015] Preferably, the time monitoring window (Δt) and the monitoring load instruction (ΔP) can be flexibly adjusted according to the actual AGC instruction transmission situation of the equipment to adapt to the AGC instruction transmission problems in different situations.

[0016] Preferably, when the AGC instruction fails to complete data transmission within a predetermined time (ΔT), an AGC instruction data transmission link abnormality alarm is issued to prompt the user to check or exit the plug-in system.

[0017] Preferably, after the AGC instruction step is grasped, the method has a self-locking function, maintaining the current AGC instruction step value until the next grasping condition is triggered, and automatically resetting the control loop after grasping to wait for the next working condition to be met.

[0018] Preferably, the method has the ability to automatically locate and schedule the start and end times of sending AGC instructions and intelligently capture the step length of AGC instructions without manual intervention, thereby improving the efficiency and accuracy of AGC instruction capture.

[0019] Preferably, in said S2, "record each sampling time point (t n ) corresponding to the AGC command value To determine the start and end time of the AGC instruction, the following steps are included:

[0020] S2-1: Get each sampling time point (t n ) of the AGC command value

[0021] S2-2: storing the obtained AGC instruction value in a temporary cache;

[0022] S2-3: Periodically check the data integrity in the temporary cache;

[0023] S2-4: Determine the start time and end time of the AGC instruction based on the data in the temporary buffer.

[0024] Preferably, in said S3, "setting a time monitoring window (Δt), during which the minimum change of the monitoring load instruction should not be less than the monitoring load instruction (ΔP)" specifically includes the following steps:

[0025] S3-1: Determine the duration of the time monitoring window (Δt);

[0026] S3-2: continuously monitor the change of load command within the time monitoring window (Δt);

[0027] S3-3: When the load instruction changes When the alarm signal is triggered;

[0028] S3-4: Record the load instruction change value and its corresponding time point.

[0029] Preferably, in said S4, "using the time monitoring window to mark the transmission start and end time of the AGC instruction" specifically includes the following steps:

[0030] S4-1: Upon receiving the first When the instruction is given, mark this time point as the start time (t n1 );

[0031] S4-2: Continue to monitor the changes in subsequent instructions until they meet The instruction appears, marking this time point as the termination time (t n2 );

[0032] S4-3: Calculate the interval between the start time and the end time (t n2 -t n1 );

[0033] S4-4: According to the interval time (t n2 -t n1 ) Determine whether the AGC instruction transmission is normal.

[0034] Preferably, in said S5, "determine whether the AGC instruction transmission is normal, by comparing (t n2 -t n1 ) and the predetermined time (ΔT)” specifically includes the following steps:

[0035] S5-1: Obtain the value of the predetermined time (ΔT);

[0036] S5-2: Comparison (t n2 -t n1 ) and (ΔT);

[0037] S5-3: If (t n2 -t n1 )<(ΔT), it is determined that the AGC instruction is transmitted within the predetermined time and the data transmission link is normal;

[0038] S5-4 If (t n2 -t n1 )≥(ΔT), it indicates that the AGC instruction data transmission link of the plug-in system is abnormal. Preferably, in the above S6, "if the data transmission link is normal, calculate the AGC instruction step length The specific steps include:

[0039] S6-1: When (t n2 -t n1 )<(ΔT), proceed to the next step;

[0040] S6-2: Calculation

[0041] S6-3: Determine whether the calculated (ΔP) is within a preset range, e.g.

[0042] S6-4: If the conditions are met, save (ΔP) to the database and reset the AGC instruction step capture control loop.

[0043] The present invention provides an AGC instruction step length capture method, which has the following beneficial effects:

[0044] 1. The present invention can automatically locate and schedule the start and end time of sending AGC instructions, and intelligently capture the step length of AGC instructions without manual intervention. The time monitoring window Δt and the monitoring load instruction ΔP can be flexibly adjusted, and the monitoring value can be set according to the actual transmission situation of the AGC instructions of the unit and the equipment. The present invention also has an abnormal alarm for the AGC instruction data transmission link. According to the delay characteristics of the unit AGC instructions, a suitable alarm threshold can be selected to exit the plug-in in time to avoid difficulties in unit load tracking and adjustment.

[0045] 2. The present invention overcomes the defects of existing methods by carefully planning a series of processes from the acceptance, monitoring and evaluation of AGC dispatch commands to the determination of their actual impact range. This not only solves the challenge that the AGC command signal may be interfered with or distorted during the propagation process, but also improves the ability of thermal power units to respond to grid demand, ensuring more efficient energy allocation in the context of the ever-changing grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram of the AGC instruction step length capture method of the present invention;

[0047] Figure 2 It is a logic diagram of the AGC instruction step length capture method of the present invention;

[0048] Figure 3 A schematic diagram of an application example of AGC instruction step capture of the present invention;

[0049] Figure 4 It is a flow chart of an AGC instruction step length capture method;

[0050] Figure 5 For S2, “record each sampling time point (t n ) corresponding to the AGC command value To determine the start and end time of the AGC instruction" flow chart;

[0051] Figure 6 The flowchart of "setting a time monitoring window (Δt), during which the minimum change of the monitoring load instruction should not be less than the monitoring load instruction (ΔP)" in S3;

[0052] Figure 7 It is a flow chart of "using the time monitoring window to mark the transmission start and end time of the AGC instruction" in S4;

[0053] Figure 8 In S5, "determine whether the AGC instruction transmission is normal, by comparing (t n2 -t n1 ) and the predetermined time (ΔT)”;

[0054] Fig. 9 In S6, "If the data transmission link is normal, calculate the AGC instruction step length ” flow chart. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solutions and advantages of the embodiments of the present disclosure more clear, the embodiments of the present disclosure are further described in detail in combination with the embodiments and drawings. The schematic implementation methods of the embodiments of the present disclosure and their descriptions are only used to explain the embodiments of the present disclosure and are not intended to limit the embodiments of the present disclosure.

[0056] Next, refer to the attached Figure 1 -Attached Fig. 9 , describes an AGC instruction step capture method of the present invention and its specific steps and implementation scenarios. This method provides a more accurate and effective solution to the problems of delay and signal instability existing in the existing methods. Through detailed step descriptions and specific examples, we can understand this process more clearly.

[0057] Starting from step one, the dispatch center sends AGC (Automatic Generation Control) instructions to each generator. This process involves communication interaction between the remote terminal RTU and the system in the power plant. In some power plants, in addition to the traditional distributed control system (DCS), programmable logic controllers (PLCs) are also introduced as external enhancement devices. These devices usually need to establish a communication bridge with the main control system through an interface machine to ensure that the instructions can be interpreted and executed in a timely and correct manner. This initial step ensures the start of the entire automatic generation control cycle.

[0058] Specifically, in the second step, we need to record the state changes of the AGC command within a specific interval. Here, the power value information at a certain time interval will be saved for subsequent comparison and analysis. These sampled data provide a basis for detecting the time interval between the initiation and completion of the actual adjustment task, which in turn supports our evaluation of the overall process efficiency and reliability and the proposal of improvement suggestions.

[0059] The next step is how to set a suitable time window to filter out the influence of non-interfering dynamics and identify the key nodes that truly represent the start and end of regulation. The selection of the time window is directly related to the strength of the anti-interference performance for subtle fluctuations, and it is also necessary to balance the requirements for rapidity and accuracy in the response time of the actual load demand change. After determining the above two indicators, the relevant hardware equipment configuration or software strategy can be adjusted accordingly to achieve optimized result output, further improve the operating efficiency of the entire energy supply network, and ultimately achieve more refined operation management and more user-friendly service quality.

[0060] The signal is judged in the second order using the set threshold (i.e. the minimum load change within Δt is at least ΔP): if the change measured during the continuous observation period exceeds the preset limit, then the variable load operation can be declared to have begun, until the value is observed again to stabilize (even so, it is necessary to pay attention to continuous tracking to avoid returning to the standby state due to sudden interference). This stage can effectively identify the key time nodes that truly represent the start and complete termination of the instruction.

[0061] The next step is to verify the real availability of the data obtained above. The specific operation is to compare whether the difference between the two recorded times falls within the normal expected value. By comparison, if the difference is less than the preset safe transmission time range, it means that there is no serious delay or loss problem interference in the whole process, and it is allowed to continue to the next step; otherwise, the administrator will be reminded that there may be communication quality risks and the cause must be found out and eliminated before continuing to carry out the remaining work steps. In this way, the source of the fault can be eliminated in the first time to avoid greater losses or adverse consequences.

[0062] If the verification results show that all communications are in compliance with the specifications, the total amount of power output change during the implementation of this adjustment order can be obtained smoothly. This value is of great significance for evaluating the response flexibility and stability of each power generation facility, and can also provide direction for subsequent optimization of the control algorithm or equipment selection.

[0063] In the last step, when it is confirmed that all the conclusions after the previous collection and verification have met the set conditions, a reset program will be started to clean up the old monitoring point records. This not only prepares space for subsequent updates, but also helps reduce memory pressure and prevents the situation where calculations cannot be restarted after an unexpected disconnection.

[0064] For example, suppose that the dispatching department located in the center of a province issues an emergency call to several local power plants at a certain moment to increase the total output by 10%. Starting from around that moment, the specific details of the instructions received at various locations become the focus of research, especially those locations where data distortion may occur due to multiple forwardings in the middle. Using the series of automated judgment steps described above, engineers can quickly capture the key turning point information during each independent execution. In this way, even in very complex actual network conditions, it is possible to ensure an accurate and comprehensive understanding of the entire process, thereby laying a solid foundation for further formulating more reasonable dispatching decisions or taking technical improvement measures for weak links.

[0065] Next, the time monitoring window (Δt) and monitoring load instruction of the present invention are described to be flexibly adjusted according to the actual AGC instruction transmission situation of the device to adapt to the AGC instruction transmission problem under different circumstances. First, the time monitoring window (Δt) is defined as the time period length used by the system when continuously collecting and processing AGC instructions, which usually ranges from 0.1 seconds to 10 seconds, and the optimal value is 1 second to ensure real-time performance and response speed. The monitoring load instruction (ΔP) indicates the load instruction change detected by the system within this time window, which ranges from 0 to 50% of the rated power, and the optimal value is 10%. The two are calculated by the formula ΔP=P(t+Δt)-P(t), where P(t) is the load instruction at time t, and (P(t+Δt)) is the load instruction at time (t+Δt), which is used to quantify the change of the load instruction.

[0066] Next, the adjustment is made according to the actual AGC instruction transmission of the device. The specific steps include: first, real-time monitoring of the communication status of the device, such as network delay, packet loss rate, etc.; second, adjusting the size of the time monitoring window (Δt) according to the monitoring results. For example, if the network delay is high, the value of (Δt) can be appropriately increased to reduce the risk of instruction loss. On the contrary, if the network condition is good, (Δt) can be reduced to improve the response speed of the system. Third, the threshold of monitoring load instructions (ΔP) is dynamically adjusted according to the amplitude of load change. For example, when the system detects a large load change, the threshold of (ΔP) can be increased to filter out some smaller noise interference and ensure the effectiveness of the signal. Specifically, in one embodiment, if the initial setting is (Δt=1) second, ΔP=10, and the network delay increases to more than 20 milliseconds during a certain period of time, in order to ensure the stability of data transmission, (Δt) is adjusted to 2 seconds, and in order to filter out noise, (ΔP) is increased to 20%, so as to more effectively capture important load instruction changes and improve the overall performance of the system.

[0067] These steps can effectively deal with AGC command transmission problems in different scenarios by dynamically adjusting the values ​​of (Δt) and (ΔP), ensuring that the system can maintain good operation in complex environments. For example, when the power station is located in a remote area with poor communication conditions, the false alarm rate in command transmission can be reduced by extending (Δt) and increasing the value of (ΔP), thereby improving the reliability and stability of the system.

[0068] Next, the method of the present invention for issuing an abnormal alarm of the AGC instruction data transmission link to prompt the user to check or exit the plug-in system when the AGC instruction fails to complete the data transmission within the predetermined time (ΔT) is described, which includes several steps. First, after receiving the AGC (Automatic Generation Control) instruction, the expected completion timestamp is calculated and the timer is started to monitor the time required for the AGC data packet from sending to reply; the specific steps include starting the timing (time point t_0), sending the AGC instruction, and ending the timing when the reply data is received. Secondly, before reaching the ΔT moment and not receiving the response, it is considered that a timeout has occurred, and the abnormal detection logic is triggered; specifically, a timeout duration threshold is set, and if the timeout value is exceeded and no response is obtained, it is considered that a problem has occurred. Finally, when the above-mentioned timeout is detected, the alarm mechanism registered in the system is immediately activated and reported to the user or management program in an appropriate form; this process is intended to alert the operator about potential link failure problems, and decide whether to automatically disconnect or recommend manual intervention to repair the communication channel according to the specific settings.

[0069] For example, in one embodiment, it is assumed that there is an automatic power generation control command adjustment process, and the AGC adjustment amount needs to be transmitted to the remote device in real time through the network interface to perform the corresponding operation. In order to ensure the efficiency and accuracy of command transmission, it is assumed that the optimal value of ΔT is set to 200ms (based on the time required for the receiving end to complete the calculation and the network delay under normal circumstances). Once the time limit is exceeded and it is not confirmed that the command has been correctly executed or the feedback information is not returned to the sender in time, it is determined that the connection is unstable or even invalid. In addition, the system will also display a notification recommending exiting or maintaining the external extension part to prevent further possible data loss risks.

[0070] Next, the AGC instruction step of the present invention is described. After the grasping, the method has a self-locking function, maintains the current AGC instruction step value until the next grasping condition is triggered, and automatically resets the control loop after grasping to wait for the next working condition to be met.

[0071] The steps include the following parts:

[0072] Grab the AGC command step: When the preset grab conditions are met, the system extracts the current AGC command step value from the current running state. This step ensures that the system can accurately obtain the required AGC command step value at a specific moment.

[0073] Start the self-locking function: Once the AGC instruction step is successfully captured, the system immediately enters the self-locking state. In this state, the system will keep the current AGC instruction step value unchanged and will not accept any new instruction changes. This ensures that the system can maintain a stable state for a period of time and avoids the impact of external interference on system stability.

[0074] Maintain AGC command step: In the self-locking state, the system will continue to maintain the captured AGC command step value. No matter how the external environment or system internal parameters change, the system will lock at the current command step value to ensure the stability and reliability of the system.

[0075] Monitoring grasping conditions: The system continuously monitors and evaluates the possibility of triggering grasping conditions again. When it detects that new grasping conditions are met, the system prepares to perform the next grasping action.

[0076] Automatic reset control loop: When the new conditions are met, the system will automatically release the self-locking state and reset the control loop. The reset system is ready for the next grasping operation and continues to execute the same process.

[0077] For example, in the AGC control of the power system, suppose that the system load changes greatly at a certain moment, causing the AGC controller to adjust the output power of the generator. The system determines that the AGC instruction step needs to be updated by monitoring the grid frequency and load changes. At this moment, the system successfully captures the current AGC instruction step value, and then immediately starts the self-locking function to fix this value to avoid other temporary interference. While the system is in the self-locking state, even if other parameters change, the system still maintains this fixed instruction step value. When the grid returns to stability or new load changes occur again, the system detects that the new capture conditions are met, and automatically resets the control loop to prepare for the next capture operation.

[0078] Specifically, assuming that the calculation formula for the AGC instruction step length is (ΔP = K f ·(f-f0)+K L ·(P L -P L0 )) Where (ΔP) represents the AGC command step size, (K f ) is the frequency sensitivity coefficient, (f) is the actual frequency, (f0) is the reference frequency, (K L ) is the load variation coefficient, (P L ) is the actual load, (P L0) is the reference load. The range and optimal values ​​of these parameters are usually determined by the actual application and system design. For example, the frequency sensitivity factor (K f ) may be set between 0.1 and 0.5, with the optimal value being 0.3; the load variation coefficient (K L ) may be set between 0.5 and 1.5, with the optimum value being 1.0. This setting is to ensure that the AGC controller can react quickly in response to frequency and load changes while maintaining stable system operation.

[0079] The meaning of this formula is to dynamically adjust the AGC instruction step size by combining frequency deviation and load deviation to ensure that the system can maintain stable and efficient operation under different working conditions. Setting the formula in this way can effectively respond to actual changes in the power grid and provide more flexible and precise control.

[0080] Next, the method of the present invention is described to have the ability to automatically locate and schedule the start and end times of sending AGC instructions and intelligently capture the step length of AGC instructions without manual intervention, thereby improving the efficiency and accuracy of AGC instruction capture.

[0081] First, the method automatically identifies and extracts the data segments of AGC instructions from the received data stream. The key to this step is to use predefined rules or algorithms to filter and match specific data formats or protocol fields that may contain AGC instructions. For example, the communication protocol of the power system, such as Modbus or DNP3, can be parsed to find messages related to AGC instructions.

[0082] Secondly, the method determines the specific start and end time of the instruction transmission by analyzing the identified AGC instruction data segment. This process usually involves processing and comparing timestamps. The specific implementation method can be to compare multiple timestamps to find the start and end time points of the AGC instruction in the data stream. For example, in a series of received messages, the timestamp of the first message containing the AGC instruction identifier is determined as the starting point of the instruction transmission, and the timestamp of the last message carrying the instruction is marked as the end point of the instruction transmission.

[0083] Next, the method intelligently captures the step information in the AGC instruction. This step involves in-depth analysis of the AGC instruction content to extract key parameters. Specifically, a pattern recognition algorithm or rule engine can be used to identify the step field and extract it. For example, if the AGC instruction is sent in binary form, the parsing algorithm will extract the step value from the data stream based on the preset byte position or displacement.

[0084] In addition, in order to improve accuracy, the method also includes a verification step for the extraction results. This means that the consistency and reliability of the extracted start and end time and step length information are ensured through multiple captures and comparisons. For example, in one embodiment, the system extracts the AGC instructions received in multiple time periods multiple times and calculates their average or mode values ​​to reduce errors and improve accuracy.

[0085] Finally, all the above steps are completed automatically without human intervention, ensuring the efficiency and automation of instruction capture. For example, during the entire process of receiving data, the system can automatically generate a report showing the start and end time and step length information of each instruction for the operator's reference.

[0086] To further optimize the performance of the method, the following formula can be used to evaluate the effectiveness of the steps:

[0087]

[0088] in, represents the actual start and end time of the (i)th time, represents the start and end time of the (i)th prediction, and (n) is the number of tests. This formula is used to calculate the mean square error (MSE) between the actual and predicted times. The smaller the (E) value, the higher the accuracy. In the optimal case, the value should be close to zero. By minimizing (E), the system can better adjust and optimize parameters and improve the accuracy and efficiency of instruction capture.

[0089] Next, the S2 of the present invention is described, recording each sampling time point (t n ) corresponding to the AGC command value To determine the start and end time of the AGC instruction, the following steps are specifically included:

[0090] S2-1: Get each sampling time point (t n ) of the AGC command value This step refers to sampling at a specific sampling time point (t n ), the system reads the current AGC command value from the automatic generation control system (AGC) The sampling time point is usually determined by a preset time interval of the system, such as once per second or once every five minutes. For example, in a specific embodiment, data is collected once every minute. When the time point t1 is 00:00:00, the AGC instruction value read by the system is Maybe 120kW.

[0091] S2-2: Store the acquired AGC instruction value in a temporary cache; this step refers to storing each AGC instruction value read from the AGC system Stored in a temporary data cache. This temporary cache is usually a space in memory that is used to store data for a short period of time for quick access and processing. Specifically, when the system obtains at t1 , it will be immediately stored in the temporary cache. If at t2, the system obtains It will also be stored in the temporary cache.

[0092] S2-3: Regularly check the data integrity in the temporary cache; This step refers to regular checks on the data in the temporary cache to ensure that all necessary data has been correctly stored and not lost. The check usually verifies continuity by calculating the timestamp of each data packet. For example, the data integrity in the temporary cache is checked every 10 seconds. If a missing is found between t3 and t4, the corresponding error handling mechanism is triggered.

[0093] S2-4: Determine the start time and end time of the AGC instruction based on the data in the temporary cache; this step uses the AGC instruction value stored in the temporary cache To determine the start and end time of the AGC command. Specifically, when a significant change in the AGC command value is detected, the system will record the time points before and after the change. These time points are the start and end time of the AGC command. For example, if the AGC command value suddenly changes from 120kW to 150kW at t5, then t5 is recorded as the start time of the new AGC command; when t 10 When the AGC command value returns from 150kW to 120kW, then t 10 It is recorded as the termination time of this AGC instruction.

[0094] Parameters(t n ) represents the nth sampling time point, Indicates that at the time point (t n ) of the AGC command value. The ranges of these two parameters are: (t n ) is a non-negative real number representing a time point since the start time; It usually varies between 0kW and the maximum output power of the power station, and the specific range depends on the installed capacity of the power station. The optimal setting usually selects the appropriate sampling frequency and data verification cycle on the premise of ensuring real-time and accuracy to avoid increasing the system burden due to frequent sampling or verification. Formula The purpose of this formula is to accurately record the real-time command value of the AGC system for subsequent analysis and control. This formula is set to ensure that changes in system commands can be captured and responded to in a timely manner.

[0095] Next, the description of S3 of the present invention is that setting a time monitoring window (Δt), during which the minimum change of the monitoring load instruction should not be less than the monitoring load instruction (ΔP) specifically includes the following steps:

[0096] S3-1: Determine the duration of the time monitoring window (Δt); This step involves determining the time interval for which the load command needs to be continuously monitored. The setting of (Δt) is usually based on the response time of the system and the actual demand. For example, if the response time of the system is short, (Δt) can be set to a few seconds; if the response time of the system is long, (Δt) can be set to a few minutes. The optimal (Δt) value depends on the specific situation of the system, and it is generally recommended to obtain the best value from the actual operating data. Specifically, assuming that in the power system, the response time of the AGC (automatic generation control) system is about 5 seconds, so (Δt) can be set to 5 seconds.

[0097] S3-2: Continuously monitor the changes in load instructions within the time monitoring window (Δt); in this step, the system will continuously collect load instruction change data during this period to ensure that any changes can be discovered in time. For example, when (Δt) is set to 5 seconds, the system will collect load instruction data once a second and record it. This process can be implemented through a timed task or interrupt mechanism to ensure the accuracy and real-time nature of the data. In one embodiment, assume that the system collects load instruction data once a second, and a total of 5 data points are collected within 5 seconds.

[0098] S3-3: When the load instruction changes When the load instruction changes beyond the preset threshold, the alarm signal is triggered; the purpose of this step is to issue an alarm when the load instruction changes beyond the preset threshold. Indicates the load command value at the beginning of monitoring. represents the load command value after time (Δt), (ΔP) is the set minimum change threshold. For example, assuming 5 seconds later If the set value is (ΔP=40)MW, the change value is 50MW, which exceeds the threshold, and thus triggers an alarm signal. This step is designed to detect abnormal changes in load instructions in a timely manner to ensure that the system can respond quickly.

[0099] S3-4: Record the load instruction change value and its corresponding time point; when it is detected that the load instruction change value exceeds (ΔP), the system will record this change value and the specific time point when it occurs. For example, the recorded data may include: change value 50MW, time point 15:30:05 on October 16, 2024. This record is used for subsequent analysis and auditing to help operation and maintenance personnel understand the changes in load instructions and optimize the system's operating strategy. Specifically, assume that at 15:30:05 on October 16, 2024, the system recorded a change event in which the load instruction increased from 800MW to 850MW.

[0100] Through the above steps, the method can effectively monitor and record the changes in load instructions, providing strong support for the safe and stable operation of the power system.

[0101] Next, the following steps are described for marking the start and end time of the transmission of the AGC instruction using the time monitoring window in S4 of the present invention:

[0102] Upon receiving the first condition that When the instruction is received, mark this time point as the starting time (t_{n1}). Here, P_{t_{n1}} represents the power value at time t_{n1}, Δt is a fixed time delay constant, which represents the time difference from the instruction being sent to the instruction being received, and ΔP is a preset threshold used to determine whether the instruction has changed. When the absolute value of the power change is greater than ΔP, it indicates that the starting phase of the AGC instruction has begun. The range of parameter Δt is usually between a few milliseconds and tens of milliseconds, and the optimal value depends on the response speed of the system. For example, in one embodiment, if at time t n1 = 10:00:01, the monitored power change |150+0.01-150|=0.01>0.005MW, then time t n1 will be marked as the start time.

[0103] Continue to monitor subsequent instructions until they meet the The instruction appears, marking this time point as the termination time (t n2 ).here, Indicates that at time t n2 The power value at the time. In fact, it means that at time t n2 After a time delay of Δt, the absolute value of the power change is less than the threshold ΔP, which means that the AGC instruction has ended. The parameter ΔP is still the previously set threshold. For example, in the above example, if at time t n2 = 10:00:10, the monitored power change |152-152-0.01| = 0.01 < 0.005MW, then time tn2 will be marked as the end time.

[0104] Calculate the interval between the start time and the end time (t n2 -t n1 ). This interval represents the duration of the entire AGC command transmission. Continuing with the above example, if t n1 =10:00:01 and t n2 =10:00:10, then the interval t n2 -t n1 =9 seconds.

[0105] According to the interval time (t n2 -t n1 ) Determine whether the AGC command transmission is normal. Usually a reasonable interval time range is set. If the actual interval time is within this range, the AGC command transmission is considered normal. Otherwise, there may be a problem in the transmission process and further inspection is required. Specifically, assuming that the calculated interval time is 9 seconds and the reasonable time range is 7 to 12 seconds, it can be determined that the AGC command transmission is normal.

[0106] The above steps ensure accurate monitoring of the AGC command transmission process, which helps to improve the operating efficiency and reliability of the system.

[0107] Next, the S5 of the present invention is described, judging whether the AGC instruction transmission is normal, by comparing (t n2 -t n1 ) and the predetermined time (ΔT) specifically include the following steps:

[0108] S5-1: Obtain the value of the predetermined time (ΔT);

[0109] S5-2: Comparison (t n2 -t n1 ) and (ΔT);

[0110] S5-3: If (t n2 -t n1 )<(ΔT), it is determined that the AGC instruction is transmitted within the predetermined time and the data transmission link is normal;

[0111] S5-4 If (t n2 -t n1 )≥(ΔT), it indicates that the AGC command data transmission link of the plug-in system is abnormal.

[0112] S5-1: Get the value of the scheduled time (ΔT). This step is to obtain the system preset time threshold (ΔT) from a configuration file or other predefined source. This threshold is used to evaluate the time efficiency of AGC command transmission. The value of the scheduled time (ΔT) can vary according to the needs of the actual application, usually at the millisecond level, such as 500 milliseconds or 1000 milliseconds. The optimal value is usually the result of comprehensive consideration of the real-time performance and stability of the system.

[0113] S5-2: Comparison (t n2 -t n1 ) and (ΔT). In this step, the system calculates the actual time difference (t n2 -t n1 ) and compared with the predetermined time (ΔT). n1 ) represents the sending time of the AGC command, (t n2 ) represents the reception time of the AGC command. The purpose of this formula is to quantify the time delay of command transmission in order to evaluate the performance of the data link. Formula (t n2 -t n1 ) is to measure the specific time from the issuance of the instruction to the reception, so as to determine whether the transmission is completed within the scheduled time.

[0114] S5-3: If (t n2 -t n1 )<(ΔT), it is determined that the AGC instruction is transmitted within the scheduled time and the data transmission link is normal. n2 -t n1 ) is less than the predetermined time (ΔT), indicating that there is no obvious problem with the data link, the instruction transmission is efficient, and the system can be considered to be operating normally. For example, in one embodiment, assuming that (ΔT) is set to 500 milliseconds, and (t n2 -t n1 ) is measured to be 300 milliseconds, the system will determine that the AGC command transmission is completed within the specified time and the link is normal.

[0115] S5-4: If (t n2 -t n1 )≥(ΔT), it indicates that the AGC command data transmission link of the plug-in system is abnormal. When the actual transmission time (t n2 -t n1 ) is equal to or greater than the preset time (ΔT), the system will trigger an abnormal alarm, prompting the plug-in system to pay attention to possible problems in the data link and require further inspection and processing. For example, if (ΔT) is set to 500 milliseconds, and (t n2 -t n1) is measured as 600 milliseconds, the system will determine that the AGC command transmission has exceeded the scheduled time and there may be a problem with the link. The operator should be reminded to check the network status or bottlenecks in the data processing process.

[0116] The above four steps together constitute the judgment logic of whether the AGC command transmission is normal or not. In this way, the stability and transmission efficiency of the data link can be effectively monitored to ensure the efficient and reliable operation of the power system.

[0117] Next, the step S6 of the present invention is described, if the data transmission link is normal, the AGC instruction step length is calculated. The specific steps include:

[0118] S6-1: When (t n2 -t n1 )<(ΔT), proceed to the next step;

[0119] S6-2: Calculation

[0120] S6-3: Determine whether the calculated (ΔP) is within a preset range, e.g.

[0121] S6-4: If the conditions are met, save (ΔP) to the database and reset the AGC instruction step capture control loop.

[0122] In step S6-1, it is first necessary to determine the difference between two time points (t n2 -t n1 ) is less than the predetermined time interval (ΔT). (t n2 ) represents the time when the AGC instruction is read for the second time, and (t n1 ) indicates the time when the first reading is obtained. (ΔT) is a preset time threshold, which is usually set to a few sampling cycles to ensure that the time difference between the two readings is within a reasonable range in order to accurately capture the changes in the AGC instructions. For example, if (ΔT) is set to 10 seconds and (t n2 -t n1 ) is equal to 5 seconds. If this condition is met, proceed to the next step.

[0123] In step S6-2, the AGC instruction step length is calculated based on the result of the previous step. here and Respectively represent the time (t n2 ) and time (t n1). By calculating the difference between these two values, we can get the change of AGC command during this period. The core of this step is to quantify the change of AGC command and provide basic data for further analysis and processing.

[0124] In step S6-3, it is determined whether the calculated (ΔP) is within a preset reasonable range. Specifically, it is necessary to verify whether the absolute value |ΔP| is greater than The coefficient 10.1 in the formula is an empirical value determined after many experiments and verifications, and is used to determine whether the AGC command change significantly exceeds the expected range. Indicates that (t n1 ) and (t n2 ) The average value of the AGC command value between these two moments. By comparing the change (ΔP) with this average value, noise and other unexpected changes can be effectively filtered out. If the calculated |ΔP| is indeed greater than the preset range, the change is considered to be effective, otherwise it is considered to be noise or invalid change.

[0125] Finally, in step S6-4, if the judgment condition in step S6-3 is met, the calculated (ΔP) is saved in the database, and the AGC instruction step capture control loop is reset. The purpose of this step is to record important change events and reset the system to prepare for the next detection. By resetting the control loop, the stability and accuracy of the system are ensured. For example, in one embodiment, if the detected (ΔP) is 500 MW, and the preset range is 150 MW (based on a coefficient of 10.1 and the average value of the AGC instruction), 500 MW is greater than 150 MW, which meets the conditions, so (ΔP) will be saved, and the control loop will be reset to prepare for the next detection.

[0126] The above steps describe in detail how to calculate and process the AGC command step size when the data transmission link is normal. These steps can effectively capture and manage command changes in the power system.

[0127] A method for capturing the step length of an AGC instruction of the present invention includes: the AGC instruction issued by the dispatching agency is transmitted to the DCS (distributed control system) at the power plant end by the RTU (remote terminal control system) through the electric power remote control method. Taking into account the configuration differences of the digital systems of different power plants, some may also integrate additional PLC (programmable logic controller) systems to assist in frequency control, and data exchange with the PLC needs to be achieved through an interface. In order to solve the problem of instruction distortion caused by a complex signal transmission network, especially to improve the rapid response capability and accuracy of the unit under the execution of automatic power generation control, this step not only enhances the tracking accuracy of load changes, but also ensures that the system responds quickly and effectively to changes in AGC instructions (step S1).

[0128] Then record each specific time (t n ) corresponds to the actual load value of AGC operation In this way, the specific time period for the start and end of the AGC dispatch command is clarified (step S2). Then a monitoring period (Δt) is set to monitor the minimum change in the load command during this period. This method helps to confirm the effective load change signal rather than noise or temporary fluctuations (steps S3) and (S4).

[0129] By defining the method for receiving and stopping receiving the specific time points of the dispatching center's load change instructions (S4), the time periods of these key stages can be marked more accurately, and further verifying whether any abnormalities have occurred during the data transmission process, such as delays or losses, by comparing the predetermined delay with the actual situation (step S5).

[0130] If it is confirmed that there is no abnormality, the subsequent operation will be performed to calculate the AGC step value This value reflects the range of change in the generator output during a command adjustment process. Once this step number is obtained, the AGC capture program will be reinitialized immediately to continuously provide the latest AGC command dynamic information and promptly respond to the system's needs for fast and smooth power adjustment (step S6).

[0131] In general, the present invention overcomes the shortcomings of existing methods by carefully planning a series of processes from the acceptance, monitoring and evaluation of AGC dispatch commands to the determination of their actual impact range - it not only solves the challenge that the AGC command signal may be interfered with or distorted during the propagation process, but also improves the ability of thermal power units to respond to grid demand, ensuring more efficient energy allocation in the context of a constantly changing grid. This is not only an effective innovation of traditional means, but is also particularly valuable and practical in today's increasingly complex and ever-changing energy management systems. Such a more refined and reliable AGC step width capture method can support more efficient and accurate identification and response to demand changes, thereby improving the flexibility and security of the entire network operation.

[0132] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of the embodiments of the present disclosure. It should be understood that the above description is only the specific implementation method of the embodiments of the present disclosure and is not intended to limit the protection scope of the embodiments of the present disclosure. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present disclosure should be included in the protection scope of the embodiments of the present disclosure.

Claims

1. A method for capturing the step length of an AGC instruction, characterized in that: The following steps are involved: S1: The dispatcher sends the AGC command, which is transmitted to the DCS system of the power plant through the power remote terminal control system RTU. Some power plants use PLC plug-in systems for auxiliary frequency regulation control, and some DCS require an interface machine to realize data interaction with PLC; S2: Record the AGC command value corresponding to each sampling time point (tn) To determine the start and end time of the AGC instruction; S3: Set the time monitoring window (Δt), during which the minimum change of the monitoring load command should not be less than the monitoring load command (ΔP); S4: Use the time monitoring window to mark the transmission start and end time of the AGC instruction, specifically: when When , it is determined that the dispatching variable load AGC instruction starts to be received; when When , it is determined that the receiving of the dispatching variable load AGC instruction is completed; S5: Determine whether the AGC instruction transmission is normal by comparing (t n2 -t n1 ) and the predetermined time (ΔT), if (t n2 -t n1 <ΔT), it indicates that the AGC instruction is transmitted within the scheduled time and the data transmission link is normal; otherwise, it indicates that the AGC instruction data transmission link of the plug-in system is abnormal; S6: If the data transmission link is normal, calculate the AGC instruction step length And automatically reset the AGC instruction step capture control loop.

2. The AGC instruction step length capture method according to claim 1, characterized in that: The time monitoring window (Δt) and the monitoring load instruction (ΔP) can be flexibly adjusted according to the actual AGC instruction transmission situation of the equipment to adapt to the AGC instruction transmission problems in different situations.

3. The AGC instruction step length capture method according to claim 1, characterized in that: When the AGC instruction fails to complete data transmission within the predetermined time (ΔT), an AGC instruction data transmission link abnormality alarm is issued, prompting the user to check or exit the plug-in system.

4. The AGC instruction step length capture method according to claim 1, characterized in that: After the AGC instruction step is grasped, the method has a self-locking function, maintaining the current AGC instruction step value until the next grasping condition is triggered, and automatically resetting the control loop after grasping to wait for the next working condition to be met.

5. A method for capturing the AGC instruction step length according to any one of claims 1 to 4, characterized in that: The method has the ability to automatically locate and schedule the start and end times of sending AGC instructions and intelligently capture the step length of AGC instructions without manual intervention, thereby improving the efficiency and accuracy of AGC instruction capture.

6. The AGC instruction step length capture method according to claim 1, characterized in that: In the S2, "record each sampling time point (t n ) corresponding to the AGC command value To determine the start and end time of the AGC instruction, the following steps are included: S2-1: Get each sampling time point (t n ) of the AGC command value S2-2: storing the obtained AGC instruction value in a temporary cache; S2-3: Periodically check the data integrity in the temporary cache; S2-4: Determine the start time and end time of the AGC instruction based on the data in the temporary buffer.

7. The AGC instruction step length capture method according to claim 1, characterized in that: In the above S3, "setting a time monitoring window (Δt), during which the minimum change of the monitoring load instruction should not be less than the monitoring load instruction (ΔP)" specifically includes the following steps: S3-1: Determine the duration of the time monitoring window (Δt); S3-2: continuously monitor the change of load command within the time monitoring window (Δt); S3-3: When the load instruction changes When the alarm signal is triggered; S3-4: Record the load instruction change value and its corresponding time point.

8. The AGC instruction step length capture method according to claim 1, characterized in that: In the above S4, "marking the transmission start and end time of the AGC instruction by using the time monitoring window" specifically includes the following steps: S4-1: Upon receiving the first When the instruction is given, mark this time point as the start time (t n1 ); S4-2: Continue to monitor the changes in subsequent instructions until they meet The instruction appears, marking this time point as the termination time (t n2 ); S4-3: Calculate the interval between the start time and the end time (t n2 -t n1 ); S4-4: According to the interval time (t n2 -t n1 ) Determine whether the AGC instruction transmission is normal.

9. The AGC instruction step length capture method according to claim 1, characterized in that: In the above S5, "determine whether the AGC instruction transmission is normal, by comparing (t n2 -t n1 ) and the predetermined time (ΔT)” specifically includes the following steps: S5-1: Obtain the value of the predetermined time (ΔT); S5-2: Comparison (t n2 -t n1 ) and (ΔT); S5-3: If (t n2 t n1 )<(ΔT), it is determined that the AGC instruction is transmitted within the predetermined time and the data transmission link is normal; S5-4 If (t n2 t n1 )≥(ΔT), it indicates that the AGC command data transmission link of the plug-in system is abnormal.

10. The AGC instruction step length capture method according to claim 1, characterized in that: In the above S6, "if the data transmission link is normal, then calculate the AGC instruction step length The specific steps include: S6-1: When (t n2 -t n1 )<(ΔT), proceed to the next step; S6-2: Calculation S6-3: Determine whether the calculated (ΔP) is within a preset range, e.g. S6-4: If the conditions are met, save (ΔP) to the database and reset the AGC instruction step capture control loop.

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