Low-frequency oscillation situation deterioration suppression method and system

Abstract

The invention discloses a low-frequency oscillation situation degradation suppression method and system. The method comprises the following steps: establishing a first heartbeat signal acquisition logic of a target coal-fired unit, and acquiring a first time interval according to the first heartbeat signal acquisition logic; generating a first sensing signal according to the first time interval in combination with a preset overrun judgment strategy; generating a first degradation control signal according to the first sensing signal in combination with a preset first degradation suppression strategy, and determining a first instruction and a second instruction according to the first degradation control signal; and implementing the first instruction and the second instruction to finish low-frequency oscillation situation deterioration suppression. The method not only reduces the risks of frequent action of the main regulating valve, serious network-related assessment, low-frequency oscillation deterioration and the like induced by a traditional low-frequency oscillation suppression method adopting strong and weak parameter conversion, but also guarantees the flexibility of peak regulation and frequency modulation of the unit while monitoring, suppressing and eliminating the low-frequency oscillation of the target coal-fired unit in real time.

Description

Technical Field

[0001] The present invention relates to the field of thermal control technology of thermal power plants, and in particular to a method and system for suppressing low-frequency oscillation state degradation. Background Art

[0002] To achieve sustainable development, my country is vigorously building a new power system with new energy as the main body. Thermal power generation is transforming from a main power source to a regulating power source, and is responsible for quickly responding to random peak-shaving and frequency-regulating tasks caused by unstable changes in intermittent renewable energy sources such as solar energy and wind energy.

[0003] The main regulating valve is a key component for regulating the load and frequency of the target coal-fired unit. Its regulating characteristics are determined by the sensitivity of the coordinated control system and the linearity of the main regulating valve flow curve. As the requirements for grid-related assessments become more stringent, in order to achieve faster response characteristics, the regulating loop parameters in the coordinated control system of the target coal-fired unit are usually strong, which makes it easy for the main regulating valve to move frequently and significantly, resulting in power outages of the target coal-fired unit, inducing low-frequency oscillation of the unit, and a sharp drop in the stability of the thermal system.

[0004] When the target coal-fired unit generates low-frequency oscillation, if it is not discovered in time and effectively suppressed, it will cause the unit to be disconnected from the grid, load loss, and even lead to catastrophic consequences such as system disconnection and damage to power generation equipment, seriously threatening the security of the power grid and even social public safety.

[0005] The traditional method of monitoring and suppressing low-frequency oscillations of target coal-fired units usually uses a pre-established prediction model for monitoring. After low-frequency oscillations occur, the parameters of the coordinated control system regulation loop are switched from a set of sensitive strong parameters to a set of slow weak parameters, and even the frequency modulation function of the frequency modulation control loop is temporarily removed to reduce the amplitude and frequency of the main regulating valve, thereby achieving the purpose of suppressing the power oscillation of the unit. This method not only requires a large amount of data to build a prediction model, but also has high requirements for equipment computing power, making it difficult to integrate into the existing target coal-fired unit distributed control system (Distributed Control System, DCS), and has poor real-time performance; and the target coal-fired unit uses a coordinated control system that is switched to weak parameters, which responds slowly to peak load and frequency modulation needs, has poor flexibility, and has serious network-related assessments.

[0006] Therefore, under the premise of ensuring the flexible operation of the target coal-fired unit, how to quickly and accurately identify the low-frequency oscillation mode of the target coal-fired unit and take corresponding control measures to suppress the low-frequency oscillation is the key to achieving safe, flexible and stable operation of the target coal-fired unit under the new power system. Summary of the invention

[0007] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0008] In view of the above existing problems, the present invention is proposed.

[0009] Therefore, the present invention provides a method and system for suppressing low-frequency oscillation situation degradation, which can solve the problems mentioned in the background technology.

[0010] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0011] In a first aspect, the present invention provides a method for suppressing low-frequency oscillation situation degradation, comprising:

[0012] Establishing a first heartbeat signal acquisition logic for the target coal-fired unit, and acquiring a first time interval according to the first heartbeat signal acquisition logic;

[0013] Generate a first sensing signal according to the first time interval and in combination with a preset over-limit judgment strategy;

[0014] Generate a first degradation control signal according to the first sensing signal and in combination with a preset first degradation suppression strategy, and determine a first instruction and a second instruction according to the first degradation control signal;

[0015] The first instruction and the second instruction are implemented to complete the suppression of low-frequency oscillation situation degradation.

[0016] As a preferred solution of the method for suppressing the deterioration of the low-frequency oscillation situation of the present invention, wherein: generating the first perception signal according to the first time interval in combination with a preset over-limit judgment strategy includes:

[0017] Setting a first threshold;

[0018] Determining whether a target parameter within a plurality of first time intervals exceeds a first threshold;

[0019] A first perception signal is generated based on several judgment results.

[0020] As a preferred solution of the method for suppressing the deterioration of low-frequency oscillation situation described in the present invention, the first heartbeat signal acquisition logic of the target coal-fired unit is established, which includes:

[0021] The first heartbeat signal is a variable that alternates between 0 and 1;

[0022] Every time a preset time interval passes, the first heartbeat signal changes once;

[0023] The preset time interval is the first time interval.

[0024] As a preferred solution of the method for suppressing the degradation of the low-frequency oscillation situation of the present invention, wherein: the determining of the first instruction and the second instruction according to the first degradation control signal comprises:

[0025] Obtaining the target coal-fired unit load instruction and the primary frequency modulation load instruction, and calculating the target coal-fired unit total load instruction;

[0026] Calculating a set value of a first PID controller according to the target coal-fired unit total load instruction and the target coal-fired unit load, and presetting a first analog quantity point as an actual value of the first PID controller;

[0027] A first switching strategy is set, and a first instruction is determined in combination with the first degradation control signal and the first PID controller.

[0028] As a preferred solution of the method for suppressing the degradation of the low-frequency oscillation situation of the present invention, wherein: the determining of the first instruction and the second instruction according to the first degradation control signal further includes:

[0029] Obtaining the target coal-fired unit load instruction and the primary frequency modulation load instruction, and calculating the target coal-fired unit total load instruction;

[0030] Calculate the difference between the target coal-fired unit total load instruction and the target coal-fired unit load as an output of the second switching strategy, and preset a second analog point as an actual value of the second PID controller or another output of the second switching strategy;

[0031] An output of a second switching strategy is determined according to the first degradation control signal, and a second instruction is determined according to the output of the second switching strategy.

[0032] As a preferred solution of the method for suppressing low-frequency oscillation situation degradation described in the present invention, the second instruction includes: a plurality of control instructions, and the number of the control instructions is the same as the number of high-pressure steam extraction regulating valves of the target coal-fired unit.

[0033] As a preferred scheme of the low-frequency oscillation situation degradation suppression method described in the present invention, wherein: the first degradation control signal is generated according to the first perception signal and combined with a preset first degradation suppression strategy, including: judging whether low-frequency oscillation occurs in the target coal-fired unit according to the first perception signal, and generating a first instruction and a second instruction under different judgment results according to the judgment result.

[0034] In a second aspect, the present invention provides a low-frequency oscillation situation degradation suppression system, comprising:

[0035] A data acquisition module, used to establish a first heartbeat signal acquisition logic for a target coal-fired unit, and acquire a first time interval according to the first heartbeat signal acquisition logic;

[0036] A signal acquisition module, configured to generate a first perception signal according to the first time interval and in combination with a preset over-limit judgment strategy;

[0037] an instruction acquisition module, configured to generate a first degradation control signal according to the first perception signal and in combination with a preset first degradation suppression strategy, and determine a first instruction and a second instruction according to the first degradation control signal;

[0038] The suppression module is used to implement the first instruction and the second instruction to complete the suppression of low-frequency oscillation situation degradation.

[0039] In a third aspect, the present invention provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the above-mentioned method when executing the computer program.

[0040] In a fourth aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program implements the steps of the method described above when executed by a processor.

[0041] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention proposes a method and system for suppressing the degradation of low-frequency oscillation situation, establishes a first heartbeat signal acquisition logic for the target coal-fired unit, and obtains a first time interval according to the first heartbeat signal acquisition logic; generates a first sensing signal according to the first time interval in combination with a preset over-limit judgment strategy; generates a first degradation control signal according to the first sensing signal in combination with a preset first degradation suppression strategy, and determines a first instruction and a second instruction according to the first degradation control signal; implements the first instruction and the second instruction to complete the suppression of the degradation of low-frequency oscillation situation. This method not only reduces the risks of frequent main regulating valve action, serious grid-related assessment, and deterioration of low-frequency oscillation induced by the traditional method of suppressing low-frequency oscillation using strong and weak parameter conversion, but also ensures the flexibility of peak load regulation and frequency regulation of the unit while real-time monitoring, suppression, and elimination of low-frequency oscillation of the target coal-fired unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0043] Figure 1A method flow chart of a method and system for suppressing low-frequency oscillation situation degradation provided by an embodiment of the present invention;

[0044] Figure 2 A diagram of the installation positions of the high-pressure steam extraction regulating valve 1 and regulating valve 2 of a target coal-fired unit of a method and system for suppressing low-frequency oscillation situation degradation provided by an embodiment of the present invention;

[0045] Figure 3 A control logic diagram of generating a first heartbeat signal (first heartbeat signal) for monitoring low-frequency oscillations provided by a method and system for suppressing low-frequency oscillation situation degradation according to an embodiment of the present invention;

[0046] Figure 4 A control logic diagram of obtaining a first perception signal of a low-frequency oscillation situation (first perception signal) in a method and system for suppressing the degradation of a low-frequency oscillation situation provided by an embodiment of the present invention;

[0047] Figure 5 A control logic diagram of a method and system for suppressing low-frequency oscillation situation degradation provided by an embodiment of the present invention;

[0048] Figure 6 A diagram showing the implementation effect of a method and system for suppressing low-frequency oscillation situation degradation provided by an embodiment of the present invention;

[0049] Figure 7 An internal structural diagram of a computer device of a method and system for suppressing low-frequency oscillation situation degradation provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0050] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0051] Example 1

[0052] Reference Figure 1-Figure 7 , which is the first embodiment of the present invention, provides a method and system for suppressing low-frequency oscillation situation degradation, including:

[0053] Before describing the embodiments of the present application in detail, some related concepts are first explained for the sake of clarity.

[0054] RS flip-flop: A "reset priority" flip-flop, that is, when the R and S drive signals are both "1" at the same time, the flip-flop is finally in the reset state

[0055] PID controller: The PID controller (Proportional-Integral-Derivative Controller) is a widely used closed-loop control strategy used to automatically adjust various industrial processes to ensure that the controlled variable (such as temperature, pressure, speed, etc.) closely tracks the set value. The PID controller works through three basic operations: Proportional (P): adjusts the output according to the current error size. The larger the error, the stronger the corrective action. Integral (I): Considers the effect of error accumulation over time to eliminate static errors. Even if there is a small but persistent error, the controller will gradually increase the output to correct it. Derivative (D): Predicts the trend of error change. If the error changes quickly, the controller will make larger adjustments in advance, which helps to reduce overshoot and oscillation.

[0056] In the existing related technologies, the low-frequency oscillation monitoring and suppression method of the target coal-fired unit usually adopts a pre-established prediction model for monitoring. When the low-frequency oscillation situation of the unit is detected, the parameters of the coordinated control system adjustment loop are switched from a set of strong parameters that are sensitive to the load response to a set of weak parameters that respond slowly, and even the frequency modulation function of the frequency modulation control loop is temporarily removed to reduce the amplitude and frequency of the main regulating valve action, thereby achieving the purpose of suppressing the power oscillation of the unit. This method not only requires a large amount of data to construct a prediction model, but also has high requirements on the computing power of the equipment, making it difficult to integrate into the existing distributed control system (DCS) of the target coal-fired unit, and has poor real-time performance; and the target coal-fired unit uses a coordinated control system after switching weak parameters, resulting in a slow response of the unit to the peak load and frequency modulation requirements of the power grid, limited operational flexibility, and serious network-related assessment of the unit. In order to overcome these problems, the present invention proposes a method for suppressing the degradation of low-frequency oscillation situation that takes into account the safety and flexibility of the target coal-fired unit.

[0057] The present application provides an effective solution to the problems existing in the prior art. Next, a plurality of embodiments will be combined to elaborate on how to implement the method for suppressing the degradation of the low-frequency oscillation state of the target coal-fired unit by assisting the high-pressure steam extraction valve control.

[0058] Figure 2 The schematic diagram of the position of the high-pressure steam extraction regulating valve 1 and regulating valve 2 of the target coal-fired unit is shown, specifically:

[0059] High-pressure heater extraction steam regulating valve 1 and regulating valve 2 are pneumatic regulating valves installed on the No. 1 high-pressure heater extraction steam pipeline and the No. 2 high-pressure heater extraction steam pipeline of the high-pressure heater extraction system of the target coal-fired unit, and are used to adjust the extraction steam flow of the No. 1 and No. 2 high-pressure heaters.

[0060] The present invention utilizes the interaction between the steam turbine body and the heat recovery system of the target coal-fired unit, and adjusts the opening of the high-pressure heater extraction regulating valve 1 and regulating valve 2 in real time through the low-frequency oscillation state degradation suppression control strategy to control the extraction flow of steam from the high-pressure cylinder of the steam turbine into the No. 1 and No. 2 high-pressure heaters, thereby achieving the purpose of changing the load of the target coal-fired unit. This example lays the foundation for the flexible peak regulation and frequency regulation of the target coal-fired unit during low-frequency oscillation by installing high-pressure heater extraction regulating valve 1 and regulating valve 2 that can quickly release the unit's heat storage and convert it into output.

[0061] Figure 1 A method flow chart of a method and system for suppressing low-frequency oscillation situation degradation is shown, including:

[0062] S101, establishing a first heartbeat signal acquisition logic for a target coal-fired unit, and acquiring a first time interval according to the first heartbeat signal acquisition logic;

[0063] In the embodiment of the present application, establishing the first heartbeat signal acquisition logic of the target coal-fired unit includes: the first heartbeat signal is a variable that alternates between 0 and 1, and the first heartbeat signal changes once every preset time interval;

[0064] In the embodiment of the present application, the following is designed: Figure 3 The first heartbeat signal acquisition device shown, wherein:

[0065] Among them, process 1: "RS trigger" output signal RS Q =0, after negation RS Q =1;

[0066] Process 2: Using the data obtained in process 1 RS Q =1 signal, the start delay time is T ON "Hysteresis setting timer 1", at this time the first heartbeat signal HS = 0;

[0067] In the embodiment of the present application, the startup delay time is set to T ON It is set to 2s, i.e., a time interval. The relevant technicians can adjust the time interval according to specific needs. When the hysteresis setting timer 1 is started, if there is no new trigger signal within 2 seconds, the first heartbeat signal HS will remain at 0; if there is a new trigger signal within 2 seconds, HS will become 1. In this way, the accuracy of the acquisition of the first heartbeat signal HS and the time interval can be ensured.

[0068] Furthermore, through T ON After a delay of T, the output signal TON1 of the "hysteresis setting timer 1" changes from 0 to 1, and the first heartbeat signal HS also changes from 0 to 1, that is, the signal HS = 0. ON After a certain time, it becomes signal HS=1;

[0069] At the same time, the first heartbeat signal HS = 1, and the start delay time is T ON "Hysteresis set timer 2";

[0070] Process 3: After delay T ON After a certain time, the output signal TON2 of "hysteresis set timer 2" changes from 0 to 1 and is connected to the set terminal S of "RS trigger";

[0071] Process 4: After the set terminal S of the "RS flip-flop" is connected to the signal TON2 = 1 in process 3, the output signal RS of the "RS flip-flop" Q From 0 to 1, the output signal RS Q =1 respectively connect to the inverted value and start the delay time as T ON The “hysteresis set timer 1” and the reset terminal R of the “RS trigger”;

[0072] In the embodiment of the present application, RS Q =1, the start delay time after accessing the inverted value is T ON After the "hysteresis setting timer 1" is set, the first heartbeat signal changes from HS=1 obtained in process 2 to HS=0;

[0073] In the embodiment of the present application, RS Q =1, connected to the reset terminal R of the "RS trigger", the output signal RS of the "RS trigger" Q From 1 to 0, continue the process 1 to 4 to generate a fixed time interval (T ON ), a low-frequency oscillation in which the variable value alternates between 0 and 1 monitors the first heartbeat signal HS.

[0074] It should be noted that the first heartbeat signal acquisition device designed above can accurately reflect the operating status of the target coal-fired unit, thereby providing a reliable time reference for low-frequency oscillation situation monitoring. In addition, the device is simple in design, easy to implement, and does not require complex computing resources. Therefore, it can be arranged in the existing target coal-fired unit distributed control system (Distributed Control System, DCS), without the need to add equipment, and has the advantages of a wide range of applications.

[0075] In the embodiment of the present application, the low-frequency oscillation monitoring first heartbeat signal HS is a periodic signal that alternates between 0 and 1 with a time interval of 2s.

[0076] In an optional embodiment, relevant technicians can use different design methods to achieve the acquisition of the first heartbeat signal, but the characteristics of the first heartbeat signal finally acquired should be periodically changed to reflect the operating status of the target coal-fired unit. For example, other microprocessors or application-specific integrated circuits (ASICs) can also be used to implement the generation logic of the first heartbeat signal to ensure the stability and accuracy of the signal. In addition, the time interval T can be flexibly adjusted through software programming or hardware design. ON The length of the heartbeat signal can be adjusted to suit different types of target coal-fired units and different operating conditions. Other sensor data, such as temperature and pressure sensors, can also be used to assist in monitoring and adjusting the generation logic of the first heartbeat signal to improve the accuracy of monitoring and the adaptability of the system. Through these sensor data, the operating status of the unit can be judged more accurately, so that when low-frequency oscillation occurs, the control strategy can be adjusted in time to ensure the stable operation of the unit.

[0077] In the embodiment of the present application, the first heartbeat signal acquisition logic is to start the delay time T ON The same as the preset time interval, the preset time interval is the first time interval, that is, the final first time interval is the start-up delay time of the first heartbeat signal acquisition device;

[0078] In an optional embodiment, the relevant technical personnel may also adopt other methods to obtain the first time interval, for example, by monitoring the real-time operating parameters of the unit, such as rotation speed, power output, etc., to dynamically determine the first time interval. In this way, the actual operating status of the unit under different operating conditions can be more accurately reflected, thereby providing a more accurate time reference for suppressing the degradation of low-frequency oscillation situation. However, no matter what measures the relevant technical personnel take to obtain the first time interval, as long as the first time interval is used for the first heartbeat signal transformation, it should be within the protection scope of this application.

[0079] S102, generating a first sensing signal according to the first time interval and in combination with a preset over-limit judgment strategy;

[0080] In an embodiment of the present application, based on the first time interval and in combination with a preset over-limit judgment strategy, generating a first perception signal includes: setting a first threshold, judging whether the target parameter within several first time intervals exceeds the first threshold, and generating a first perception signal based on several judgment results.

[0081] In the embodiment of the present application, the first threshold is set to 18MW, the target parameter adopts the peak-to-peak value of the load fluctuation, and the number of judgments is 2. Therefore, the present application judges whether the peak-to-peak value of the load fluctuation within 2s exceeds the power limit of 18MW. If it exceeds the power limit, the signal is maintained for 4s, and the power limit judgment within the next 2s is continued. Combined with the two judgment results, it is comprehensively identified whether the load fluctuation of the target coal-fired unit exceeds the power limit, and then the first perception signal is generated.

[0082] In an optional embodiment, the relevant technical personnel can set a specific first threshold value and target parameter or judgment number according to actual needs to adapt to different monitoring needs and unit characteristics. For example, if the monitoring target is the frequency fluctuation of the unit, then the threshold value of the frequency fluctuation can be set, and whether the frequency fluctuation exceeds the threshold value can be monitored. For example, if the monitoring target is the temperature fluctuation of the unit, then the threshold value of the temperature fluctuation can be set, and whether the temperature fluctuation exceeds the threshold value can be monitored. However, it should be agreed that no matter which data the relevant technical personnel use as the first threshold value at the design level, or other target parameters are selected as monitoring standards, or how many times the judgment logic is selected, as long as it is to obtain the first perception signal from the first time interval by similar means, it should be within the scope of protection of this application.

[0083] In the embodiment of the present application, the first threshold is set to 18MW, the target parameter adopts the peak value of load fluctuation, the number of judgments is 2, and the specific steps of generating the first perception signal can be as follows (eg Figure 4 shown):

[0084] Step 1: Determine the first T ON During the time, whether the peak value of load fluctuation (target parameter) exceeds the low-frequency oscillation power limit (first threshold);

[0085] 1) When the first heartbeat signal HS=1 is obtained, that is, T ON The maximum load of the target coal-fired unit within the time period;

[0086] Among them, process 5: input the target coal-fired unit load MW signal to the "analog time domain statistical function module 1" (this module is used to count the time integral, average or maximum and minimum statistical results of the analog input signal X within a period of time) of the switch to be counted SET (when the SET access signal is 1, it indicates the start of statistics, and when the SET access signal is 0, it indicates the end of statistics), and set the module operation mode to "calculate the maximum value";

[0087] Process 6: Connect the low-frequency oscillation monitoring first heartbeat signal HS generated in process 4 to the statistical switch SET terminal of the "analog quantity time domain statistical function module 1";

[0088] Process 7: Through the analog time domain statistical function module 1, the first heartbeat signal HS = 1, that is, the first T ON The maximum load of the target coal-fired unit within the time period (unit load peak) MW max1 , and input it into the "Subtraction 1" calculation module;

[0089] Process 8: Input the target coal-fired unit load MW signal of process 5 and the first heartbeat signal HS of low-frequency oscillation monitoring generated by process 4 into the "analog quantity time domain statistical function module 2" with statistical switch SET, and set the module operation mode to "calculate minimum value". Then, the analog quantity time domain statistical function module 2 can be used to calculate the first heartbeat signal HS = 1, that is, the first T ON Minimum value of target coal-fired unit load within the time period (unit load trough) MW min1 , input into the "Subtraction 1" calculation module;

[0090] 2) Get the first T ON Peak value of unit load fluctuation within the time period;

[0091] Step 9: The first T obtained in step 7 ON The maximum load of the target coal-fired unit in the time period is MW max1 and the first T obtained in process 8 ON The minimum load of the target coal-fired unit in the time period MW min1 When the first heartbeat signal HS=1 is input into the "subtraction 1" calculation module, the first T ON The peak-to-peak value μ of the load fluctuation from peak to trough of the target coal-fired unit within the time period MW1 ,Right now

[0092] μ MW1 =MW max1 -MW min1

[0093] And μ MW1 Enter into "greater than module 1";

[0094] 3) Determine the first T ON Whether the peak value of the unit load fluctuation exceeds the low-frequency oscillation power limit within the time period;

[0095] Step 10: The first T obtained in step 9 ON The peak value μ of the load fluctuation of the target coal-fired unit within the time period MW1 Compared with the preset threshold value H1 of "greater than module 1", the judgment signal T is output H1 ;

[0096] That is: if μ MW1 >H1, then the judgment signal TH1 The output is 1, which means the first T ON The peak value of the unit load fluctuation during the time period exceeds the low-frequency oscillation power limit; otherwise, the judgment signal T H1 The output is 0, which is the first T ON The peak value of the unit load fluctuation within the time period does not exceed the low-frequency oscillation power limit;

[0097] And the judgment signal T H1 Input to the "Hysteresis Reset" module;

[0098] In the embodiment of the present application, the preset threshold value H1 is set to 18MW, and relevant technicians can set other threshold data according to actual needs.

[0099] 4) Keep T H1 =1 signal, wait for the second T ON Time interval low frequency oscillation judgment;

[0100] Process 11: Judgment signal T of process 10 H1 The delay time from input to reverse is T OFF1 In the "Hysteresis Reset Timer 1" module;

[0101] If T H1 If the output is 1, the "hysteresis reset timer 1" module outputs TD OFF1 =1;

[0102] If the input signal T of the "hysteresis reset timer 1" module H1 After the output changes from 1 to 0, the delay T OFF1 After the time, the output signal TD of the "Hysteresis reset timer 1" module OFF1 It will change from 1 to 0, thus realizing the signal T H1 Delay disappears, wait for T H2 The purpose of the judgment result;

[0103] And will output TD OFF1 The signal is sent to the "Logical AND" module.

[0104] In the embodiment of the present application, the anti-delay time T OFF1 It is set to 4s. Relevant technicians can set the anti-delay time threshold data according to actual needs.

[0105] Step 2: Determine the second T ON Time, whether the peak value of load fluctuation exceeds the low-frequency oscillation power limit;

[0106] 1) When the first heartbeat signal HS=0 is obtained, that is, T ON The maximum load of the target coal-fired unit within the time period;

[0107] Process 12: Input the target coal-fired unit load MW signal of process 5 into the "analog quantity time domain statistical function module 3" with statistical switch SET, and set the module operation mode to "calculate maximum value";

[0108] The low-frequency oscillation monitoring first heartbeat signal HS generated in process 4 is inverted and connected to the statistical switch SET terminal of the "analog quantity time domain statistical function module 3";

[0109] Through the analog time domain statistical function module 3, the first heartbeat signal HS = 0, that is, the second T ON The maximum load of the target coal-fired unit in the time period is MW max2 , and input it into the "Subtraction 2" calculation module;

[0110] Process 13: Similarly, using the analog time domain statistics function module 4 and setting the module operation mode to "calculate minimum value", the first heartbeat signal HS = 0, that is, the second T ON The minimum load of the target coal-fired unit in the time period MW min2 , input into the "Subtraction 2" calculation module;

[0111] 2) Get the second T ON Peak value of unit load fluctuation within the time period;

[0112] Step 14: The second T obtained in step 12 ON The maximum load of the target coal-fired unit in the time period is MW max2 and the second T obtained in process 13 ON The maximum load of the target coal-fired unit in the time period is MW min2 Input into the "Subtraction 2" calculation module, and get the first heartbeat signal HS = 0, the second T ON The peak value μ of the load fluctuation of the target coal-fired unit within the time period MW2 ,Right now

[0113] μ MW2 =MW max2 -MW min2

[0114] And μ MW2 Enter into "greater than module 2";

[0115] 3) Determine the second T ON Whether the peak value of the unit load fluctuation exceeds the low-frequency oscillation power limit within the time period;

[0116] Step 15: The second T obtained in step 14 ON The peak value μ of the load fluctuation of the target coal-fired unit within the time period MW1Compared with the preset threshold value H2 of "greater than module 2", the judgment signal T is output H2 ;

[0117] That is: if μ MW1 >H2, then the judgment signal T H2 The output is 1, that is, the second T ON The peak value of the unit load fluctuation during the time period exceeds the low-frequency oscillation power limit;

[0118] Otherwise, the judgment signal T H2 The output is 0, that is, the second T ON The peak value of the unit load fluctuation within the time period does not exceed the low-frequency oscillation power limit;

[0119] And the judgment signal T H2 Input to the "Hysteresis Reset" module;

[0120] In the embodiment of the present application, the preset threshold value H2 is set to 18MW, and relevant technicians can set other threshold data according to actual needs.

[0121] 4) Keep T H2 = 1 signal to wait for the first T ON Time interval low frequency oscillation judgment result;

[0122] Process 16: Judgment signal T of process 15 H2 The delay time from input to reverse is T OFF2 In the "Hysteresis Reset Timer 2" module;

[0123] If T H2 If the output is 1, the "hysteresis reset timer 2" module outputs TD OFF2 =1;

[0124] If T H2 After the output changes from 1 to 0, the "hysteresis reset" module delays T OFF2 After time, output TD OFF2 From 1 to 0, thus realizing signal T H2 The delay disappears, waiting for T H1 The purpose of the judgment result;

[0125] And will output TD OFF2 The signal is sent to the "Logical AND" module.

[0126] In the embodiment of the present application, the anti-delay time T OFF2 It is set to 4s. Relevant technicians can set the anti-delay time threshold data according to actual needs.

[0127] Step 3, generating a first low-frequency oscillation situation perception signal;

[0128] Process 17: Output process 11 to TD OFF1 Signal and Process 16 Output TD OFF2 The signal is input into the "logic AND" module, and a "logic AND" judgment is performed to generate the first low-frequency oscillation situation perception signal LFP;

[0129] That is: if the "Logic AND" module input signal TD OFF1 Signals and TD OFF2 If the signals are all 1, the "Logic AND" module outputs the first low-frequency oscillation situation sensing signal LFP=1, and the target coal-fired unit has low-frequency oscillation;

[0130] If the "Logic AND" module input signal TD OFF1 Signals and TD OFF2 If there is a 0 signal in both signals, the "logic AND" module outputs the first low-frequency oscillation situation sensing signal LFP=0, and the target coal-fired unit does not have low-frequency oscillation.

[0131] It should be noted that the benefit of generating the first perception signal according to the first time interval and the preset over-limit judgment strategy is that it can timely capture the early signs of low-frequency oscillation, so as to take corresponding suppression measures to avoid further development of oscillation. In addition, by setting the "hysteresis reset" module and the "hysteresis reset timer", it is possible to effectively avoid misjudgment caused by instantaneous fluctuations and ensure the accuracy and stability of the first perception signal of the low-frequency oscillation situation. In practical applications, by adjusting the statistical cycle of the "analog quantity time domain statistical function module" and the calculation method of the "subtraction" module, it is possible to flexibly adapt to different types of target coal-fired units and different operating conditions, thereby improving the adaptability and reliability of the system. Finally, the first perception signal LFP of the low-frequency oscillation situation output by the "logic and" module provides intuitive low-frequency oscillation status information for operators, which helps to take measures in time to ensure the stable operation of the power system.

[0132] S103, generating a first degradation control signal according to the first sensing signal and in combination with a preset first degradation suppression strategy, and determining a first instruction and a second instruction according to the first degradation control signal;

[0133] In an embodiment of the present application, a hysteresis reset timer and a control strategy based on the hysteresis reset timer are designed as a first degradation suppression strategy, and a first degradation control signal is obtained by passing the first sensing signal through the hysteresis reset timer. The main purpose is to effectively suppress the further development of the oscillation through a preset control strategy in the early stage of low-frequency oscillation situation degradation.

[0134] In the embodiment of the present application, according to the first perception signal, combined with the preset first degradation suppression strategy, the specific steps of generating the first degradation control signal may be as follows:

[0135] Among them, process 18: input the low-frequency oscillation situation first perception signal LFP obtained in process 17 into the inverse delay time T OFF3 In the "Hysteresis Reset Timer 3" module;

[0136] Process 19: After the low-frequency oscillation state first perception signal LFP is processed by the "hysteresis reset timer 3" module, a low-frequency oscillation state first degradation control signal LFPC is generated, that is,

[0137] If the input signal LFP of the "hysteresis reset timer 3" module is 1, the "hysteresis reset timer 3" module outputs the low frequency oscillation state first degradation control signal LFPC=1;

[0138] If the input signal LFP of the "hysteresis reset timer 3" module changes from 1 to 0, the delay T OFF3 After a certain time, the “hysteresis reset” module outputs the low-frequency oscillation state first degradation control signal LFPC from 1 to 0;

[0139] In the embodiment of the present application, the anti-delay time T OFF3 It is set to 60s. Relevant technicians can set the anti-delay time threshold data according to actual needs.

[0140] In the embodiment of the present application, determining the first instruction and the second instruction according to the first degradation control signal includes:

[0141] Obtaining the target coal-fired unit load instruction and the primary frequency modulation load instruction, and calculating the target coal-fired unit total load instruction;

[0142] Calculating a set value of the first PID controller according to the target coal-fired unit total load instruction and the target coal-fired unit load, and presetting a first analog quantity point as an actual value of the first PID controller;

[0143] A first switching strategy is set, and a first instruction is determined in combination with a first degradation control signal and a first PID controller.

[0144] In an embodiment of the present application, the target coal-fired unit total load instruction is the sum of the target coal-fired unit load instruction and the primary frequency modulation load instruction, and the setting value of the first PID controller is the difference between the target coal-fired unit total load instruction and the target coal-fired unit load.

[0145] In the embodiment of the present application, the first switching strategy is to select different outputs as the main regulating valve control instructions according to whether load oscillation occurs in the target coal-fired unit.

[0146] It should be noted that the present application uses the input switch 1 to implement the function of the first switching strategy.

[0147] Specifically, Figure 5 As shown:

[0148] Wherein, process 20: inputting the target coal-fired unit load command MWD signal into the “addition module”;

[0149] Process 21: Input the primary frequency modulation load instruction FMED signal of the target coal-fired unit into the “addition module”;

[0150] Process 22: Add the target coal-fired unit load instruction MWD signal obtained in process 20 and the primary frequency modulation load instruction FMED signal obtained in process 21 to obtain the target coal-fired unit total load instruction SMW signal; that is,

[0151] SMW=MWD+FMED;

[0152] And input the target coal-fired unit total load command SMW signal into the "subtraction 3" calculation module;

[0153] Process 23: Input the target coal-fired unit load MW signal into the “Subtraction 3” calculation module;

[0154] Process 24: The target coal-fired unit total load command SMW signal obtained in process 22 and the target coal-fired unit load MW signal obtained in process 23 are processed by the "subtraction 3" calculation module to obtain the set value SP of the first PID controller of the steam turbine main control T ,Right now:

[0155] SP T =SMW-MW;

[0156] And set the value SP T Input to the first PID controller of the steam turbine master control and the Y terminal of "input switch 2" respectively;

[0157] Process 25: Use analog point A1 as actual value PV T Input to the first PID controller of the steam turbine master;

[0158] Process 26: Using the set value SP obtained in process 24 T And the actual value PV obtained in process 25 T , calculate and obtain the real-time main regulating valve control instruction TPID according to the first PID controller; and input the real-time main regulating valve control instruction TPID to the N terminal of "input switch 1";

[0159] In the embodiment of the present application, the analog point A1 is set to a constant of 0; the proportion (P) of the first PID controller of the steam turbine master control is set to 0.06, and the integral (I) is set to 15s. Relevant technicians can adjust the parameters of the first PID controller according to actual needs.

[0160] Process 27: Select the output of the Y or N terminal of the "input switch 1" as the main valve control instruction according to whether load oscillation occurs in the target coal-fired unit; that is, when the first degradation control signal LFPC of the low-frequency oscillation situation obtained in process 19 is 1, the output of the Y terminal of the "input switch 1" is selected as the main valve control instruction, that is, the main valve control instruction TPID obtained in process 26 is maintained; when the first degradation control signal LFPC of the low-frequency oscillation situation obtained in process 19 is 0, the output of the N terminal of the "input switch 1" is selected as the main valve control instruction, that is, the real-time main valve control instruction TPID obtained in process 26.

[0161] In the embodiment of the present application, determining the first instruction and the second instruction according to the first degradation control signal further includes:

[0162] Obtaining the target coal-fired unit load instruction and the primary frequency modulation load instruction, and calculating the target coal-fired unit total load instruction;

[0163] Calculate the difference between the target coal-fired unit total load instruction and the target coal-fired unit load as an output of the second switching strategy, and preset the second analog point as the actual value of the second PID controller or another output of the second switching strategy;

[0164] An output of a second switching strategy is determined according to the first degradation control signal, and a second instruction is determined according to the output of the second switching strategy.

[0165] The second instruction includes: a plurality of control instructions, and the number of the control instructions is the same as the number of the high-pressure steam extraction regulating valves of the target coal-fired unit.

[0166] In the embodiment of the present application, the number of high-pressure steam extraction regulating valves of the target coal-fired unit is set to two, so the number of control instructions is two.

[0167] It should be noted that the present application uses the input switch 2 to implement the function of the second switching strategy.

[0168] Specifically, Figure 5 As shown:

[0169] Among them, process 28: input the analog quantity A2 into the actual value PV of the second PID controller of the high-pressure steam extraction regulating valve G and the N terminal of "Input Switcher 2";

[0170] Process 29: Select the output of the Y or N terminal of "input switch 2" as the set value SP of the second PID controller of the high-pressure steam extraction regulating valve according to whether the target coal-fired unit has load oscillation G ;

[0171] That is, when the low-frequency oscillation state first degradation control signal LFPC obtained in process 19 is 1, the output of the Y terminal of "input switch 2" is selected as the setting value SP of the second PID controller of the high-pressure steam extraction valve G , that is, SP obtained in process 24 T ,Right now:

[0172] SP G =SP T ;

[0173] When the low-frequency oscillation state first degradation control signal LFPC obtained in process 19 is 0, the output of the N terminal of "input switch 2" is selected as the main regulating valve control instruction, that is, the analog quantity A2 obtained in process 28, that is:

[0174] SP G =A2;

[0175] Process 30: Use the actual value PV obtained in process 28 G and the set value SP obtained in process 29 G , the real-time high-pressure steam extraction regulating valve final control instruction GPID is calculated according to the second PID controller, and sent to the high-pressure steam extraction regulating valve 1 and regulating valve 2 respectively.

[0176] In the embodiment of the present application, the analog point A2 is generally set to a constant of 0; the proportion (P) of the second PID controller of the high-pressure steam extraction regulating valve is set to 2, and the integral (I) is set to 6s. Relevant technicians can adjust the parameters of the second PID controller according to actual needs.

[0177] In an embodiment of the present application, based on the first perception signal and in combination with a preset first degradation suppression strategy, generating a first degradation control signal includes: judging whether low-frequency oscillation occurs in the target coal-fired unit based on the first perception signal, and generating a first instruction and a second instruction under different judgment results based on the judgment result.

[0178] It should be noted that step S103 can respond to the changes in the operating state of the target coal-fired unit in a timely manner, thereby effectively suppressing the degradation of the low-frequency oscillation situation. By real-time monitoring of unit load fluctuations and combining with the preset control strategy, the system can automatically adjust the control instructions to adapt to different operating conditions. When a low-frequency oscillation situation is detected, the system generates a first degradation control signal, and through the coordinated work of the first PID controller and the second PID controller, outputs the corresponding control instructions to stabilize the unit load and prevent the oscillation from intensifying. In addition, by setting analog points A1 and A2, the system can further optimize the control effect to ensure that good control performance can be maintained under various operating conditions. The automation and intelligence of the entire control process greatly improves the operating stability and safety of the target coal-fired unit.

[0179] S104, executing the first instruction and the second instruction to complete the suppression of low-frequency oscillation situation degradation.

[0180] It should be noted that after obtaining the specific first instruction and the second instruction, the low-frequency oscillation state degradation suppression of the coal-fired unit can be achieved by adjusting the corresponding position valves in the target coal-fired unit while taking into account the flexibility adjustment.

[0181] In summary, the present invention proposes a method for suppressing the deterioration of low-frequency oscillation that takes into account the safety and flexibility of the target coal-fired unit. Starting from the state of the target coal-fired unit itself, the first heartbeat signal of low-frequency oscillation monitoring is constructed to identify the low-frequency oscillation situation in real time. When the unit has low-frequency oscillation, the control target of the unit is divided into two categories: suppressing low-frequency oscillation to ensure the safety of unit operation and maintaining load regulation sensitivity to ensure the flexibility of unit operation. Among them, a method of keeping the current opening of the main regulating valve unchanged during low-frequency oscillation is adopted to suppress the load oscillation caused by the frequent action of the main regulating valve to ensure the safety of unit operation; a high-pressure steam extraction regulating valve that can quickly release the unit's heat storage and convert it into output is used as a means of regulating power during low-frequency oscillation of the unit to temporarily replace the peak-shaving and frequency-regulating functions of the main regulating valve to ensure the flexibility of unit operation. This method not only reduces the risks of frequent main regulating valve action, serious grid-related assessment, and deterioration of low-frequency oscillation induced by the traditional method of suppressing low-frequency oscillation using strong and weak parameter conversion, but also ensures the flexibility of unit peak-shaving and frequency regulation while real-time monitoring, suppression, and elimination of low-frequency oscillation of the target coal-fired unit.

[0182] The control strategy of the present invention is simple to construct, has a high degree of automation, is compatible with existing system hardware, does not require additional equipment, has a short recovery period, and has a wide range of applications.

[0183] This embodiment also provides a low-frequency oscillation situation degradation suppression system, including:

[0184] A data acquisition module, used to establish a first heartbeat signal acquisition logic for a target coal-fired unit, and acquire a first time interval according to the first heartbeat signal acquisition logic;

[0185] A signal acquisition module, configured to generate a first perception signal according to a first time interval and in combination with a preset over-limit judgment strategy;

[0186] An instruction acquisition module, configured to generate a first degradation control signal according to the first sensing signal and in combination with a preset first degradation suppression strategy, and determine a first instruction and a second instruction according to the first degradation control signal;

[0187] The suppression module is used to implement the first instruction and the second instruction to complete the suppression of low-frequency oscillation situation degradation.

[0188] The above-mentioned unit modules may be embedded in or independent of a processor in a computer device in the form of hardware, or may be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to the above-mentioned modules.

[0189] This embodiment also provides a computer device, which may be a terminal, and its internal structure diagram may be as shown in FIG. Figure 7 As shown. The computer device includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a method for suppressing low-frequency oscillation state degradation is implemented. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer device can be a touch layer covered on the display screen, or a button, trackball or touchpad set on the computer device housing, or an external keyboard, touchpad or mouse, etc.

[0190] This embodiment further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the following steps are implemented:

[0191] Establishing a first heartbeat signal acquisition logic for the target coal-fired unit, and acquiring a first time interval according to the first heartbeat signal acquisition logic;

[0192] Generate a first sensing signal according to the first time interval and in combination with a preset over-limit judgment strategy;

[0193] According to the first sensing signal, in combination with a preset first degradation suppression strategy, a first degradation control signal is generated, and a first instruction and a second instruction are determined according to the first degradation control signal;

[0194] The first instruction and the second instruction are implemented to complete the suppression of low-frequency oscillation situation degradation.

[0195] Example 2

[0196] Reference Figure 6 , which is an embodiment of the present invention, provides a method and system for suppressing low-frequency oscillation situation degradation. In order to verify the beneficial effects of the present invention, scientific demonstration is carried out through experiments.

[0197] A certain ultra-supercritical direct current target coal-fired unit with a rated load of 660MW was initially operated under the conditions of a load instruction of 332MW, a unit load of 330MW, and a high-pressure steam extraction regulating valve of 50% opening. During this period, the main regulating valve frequently operated between 50% and 55%, resulting in the unit load rising to 339MW at 15.5s, and then decreasing to 321MW at 16.4s. The unit load rose to 340MW at 18.1s, and then decreased to 319MW at 19.1s. The load fluctuation exceeded the low-frequency oscillation load limit twice within 2s, generating the first perception signal of the low-frequency oscillation situation.

[0198] At 20 seconds, the first sensing signal of the low-frequency oscillation situation triggers the action of the first degradation control signal of the low-frequency oscillation situation. The high-pressure steam extraction regulating valve temporarily replaces the main regulating valve as a means of adjusting the power of the unit. The main regulating valve maintains the opening of 51.5% when the first degradation control signal of the low-frequency oscillation situation is activated, and lasts for 60 seconds until the action of the first degradation control signal of the low-frequency oscillation situation disappears, which effectively eliminates the low-frequency oscillation of the unit caused by the frequent action of the main regulating valve.

[0199] When the unit was running for 50s, the load command increased from 332MW to 338MW at 12MW / min. At this time, the main regulating valve command remained unchanged, and the high-pressure steam extraction regulating valve was gradually closed from 50% opening to 45% to adjust the unit load to 337MW at 80s. This method can not only eliminate the low-frequency oscillation of the unit, but also make up for the shortcoming of the unit load response lag caused by the traditional method of suppressing low-frequency oscillation by switching the control parameters of the coordinated control system from strong parameters to weak parameters.

[0200] In summary, the control method of this patent utilizes the interaction between the turbine body and the heat recovery system of the target coal-fired unit, and adjusts the opening of the high-pressure heater extraction regulating valve 1 and regulating valve 2 in real time through the low-frequency oscillation situation degradation suppression control strategy to control the extraction steam flow entering the No. 1 and No. 2 high-pressure heaters from the high-pressure cylinder of the turbine, thereby changing the load of the target coal-fired unit, achieving the purpose of real-time monitoring, suppression, and elimination of low-frequency oscillations of the target coal-fired unit, while taking into account the flexibility of peak regulation and frequency regulation of the target coal-fired unit when low-frequency oscillations occur, thereby improving the safe, flexible and stable operation of the coal-fired power generation unit during the grid connection period.

[0201] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

[0202] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of complete hardware embodiments, complete software embodiments, or embodiments in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiments of the present application can be implemented in various computer languages, for example, object-oriented programming language Java and literal scripting language JavaScript, etc.

[0203] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0204] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0205] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0206] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications falling within the scope of the present application.

[0207] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for suppressing low-frequency oscillation situation degradation, characterized in that: include: Establishing a first heartbeat signal acquisition logic for the target coal-fired unit, and acquiring a first time interval according to the first heartbeat signal acquisition logic; Generate a first sensing signal according to the first time interval and in combination with a preset over-limit judgment strategy; Generate a first degradation control signal according to the first sensing signal and in combination with a preset first degradation suppression strategy, and determine a first instruction and a second instruction according to the first degradation control signal; The first instruction and the second instruction are implemented to complete the suppression of low-frequency oscillation situation degradation.

2. The method for suppressing low-frequency oscillation situation degradation according to claim 1, characterized in that: The generating a first sensing signal according to the first time interval and in combination with a preset over-limit judgment strategy includes: Setting a first threshold; Determining whether a target parameter within a plurality of first time intervals exceeds a first threshold; A first perception signal is generated based on several judgment results.

3. The method for suppressing low-frequency oscillation situation degradation according to claim 2, characterized in that: The first heartbeat signal acquisition logic of establishing the target coal-fired unit includes: The first heartbeat signal is a variable that alternates between 0 and 1; Every time a preset time interval passes, the first heartbeat signal changes once; The preset time interval is the first time interval.

4. The method for suppressing low-frequency oscillation situation degradation according to claim 3, characterized in that: The determining the first instruction and the second instruction according to the first degradation control signal comprises: Obtaining the target coal-fired unit load instruction and the primary frequency modulation load instruction, and calculating the target coal-fired unit total load instruction; Calculating a set value of a first PID controller according to the target coal-fired unit total load instruction and the target coal-fired unit load, and presetting a first analog quantity point as an actual value of the first PID controller; A first switching strategy is set, and a first instruction is determined in combination with the first degradation control signal and the first PID controller.

5. The method for suppressing low-frequency oscillation situation degradation according to claim 4, characterized in that: The determining the first instruction and the second instruction according to the first degradation control signal further includes: Obtaining the target coal-fired unit load instruction and the primary frequency modulation load instruction, and calculating the target coal-fired unit total load instruction; Calculate the difference between the target coal-fired unit total load instruction and the target coal-fired unit load as an output of the second switching strategy, and preset a second analog point as an actual value of the second PID controller or another output of the second switching strategy; An output of a second switching strategy is determined according to the first degradation control signal, and a second instruction is determined according to the output of the second switching strategy.

6. The method for suppressing low-frequency oscillation situation degradation according to claim 5, characterized in that: The second instruction includes: a plurality of control instructions, and the number of the control instructions is the same as the number of high-pressure steam extraction regulating valves of the target coal-fired unit.

7. The method for suppressing low-frequency oscillation situation degradation according to claim 6, characterized in that: The generating of the first degradation control signal according to the first sensing signal and the preset first degradation suppression strategy includes: judging whether low-frequency oscillation occurs in the target coal-fired unit according to the first sensing signal, and generating the first instruction and the second instruction under different judgment results according to the judgment result.

8. A low-frequency oscillation situation degradation suppression system, characterized in that: include: A data acquisition module, used to establish a first heartbeat signal acquisition logic for a target coal-fired unit, and acquire a first time interval according to the first heartbeat signal acquisition logic; A signal acquisition module, configured to generate a first perception signal according to the first time interval and in combination with a preset over-limit judgment strategy; an instruction acquisition module, configured to generate a first degradation control signal according to the first perception signal and in combination with a preset first degradation suppression strategy, and determine a first instruction and a second instruction according to the first degradation control signal; The suppression module is used to implement the first instruction and the second instruction to complete the suppression of low-frequency oscillation situation degradation.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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