Active detection method and system for state of coal power unit control system

Abstract

The invention discloses an active detection method and system for the state of a coal-fired generator set control system, and belongs to the technical field of coal-fired generator set control, and the method comprises the steps: a, enabling a state detection system to be connected to each target control system through an I / O hard wiring; step b, respectively sending analog quantity and digital quantity signals for verification aiming at each control logic page of each target control system, and returning the analog quantity and digital quantity signals after operation of the target control systems; and c, the state detection system comprehensively analyzes analog quantity and digital quantity signal verification results, and judges and controls the operation state of the system. Analog quantity and digital quantity signal detection is adopted at the same time, the state detection system and the target control system are connected in an I / O hard wiring mode, the influence of electromagnetic interference between electrons of a power plant and analog quantity signal noise is reduced, and the accuracy of state detection is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of coal-fired power generation unit control, and in particular to an active detection method and system for the control system state of a coal-fired power generation unit. Background Art

[0002] The core control system of coal-fired power units mainly includes: unit distributed control system (DCS), turbine digital electro-hydraulic control system (DEH), turbine emergency trip system (ETS), boiler furnace safety system (FSS), and generator cooling protection system.

[0003] Among them, the distributed control system (DCS) is the control center of the coal-fired power unit, which uses computer, communication and screen display technology to realize data collection, control and protection functions of the production process.

[0004] The steam turbine digital electro-hydraulic control system (DEH) is an important component of the coal-fired steam turbine generator set and is a regulating controller for the start-up, stop, normal operation and accident conditions of the steam turbine.

[0005] The turbine emergency trip system (ETS) receives the shutdown signal from the local primary / secondary instruments and controls the shutdown solenoid valve to shut down the turbine unit in an emergency to protect the safety of the turbine according to the requirements of safe operation of the turbine.

[0006] The boiler furnace safety system (FSS) is a protection system that prevents unsafe conditions caused by the mixture of fuel and air in the furnace, and can quickly cut off all fuel entering the boiler furnace under critical conditions to prevent destructive accidents such as deflagration and explosion, thereby ensuring the safety of the furnace.

[0007] The generator cooling protection system is a protection system that trips and stops the generator operation in time when it detects that the temperature of core components such as the generator cooler, collector ring, stator core, etc. continues to rise, or that the hydrogen, sealing oil, and cooling water are operating abnormally, which may endanger the safe operation of the generator.

[0008] The control logic of coal-fired power units refers to the logical structure that controls the boiler, steam turbine, and generator set as a whole unit, which mainly includes data acquisition system control logic, analog control system control logic, switch and sequence control system control logic, public control system control logic, etc.

[0009] In order to detect network attacks that tamper with the target control system logic, unauthorized changes to the control system status, or control system failures, it is necessary to perform real-time detection of the controller's operating status.

[0010] In the existing technical solutions, CN113958377A discloses a real-time online monitoring system and method for steam turbine network security, which utilizes mirror data acquisition, synchronous acquisition of real-time and analog data, and realizes real-time online monitoring of steam turbine network security through network data acquisition, system operation result monitoring, and comprehensive analysis. However, this solution only uses analog signal detection for the control unit. If a single control unit monitoring module fails, it will affect the final comprehensive analysis results and cause monitoring failure. Summary of the invention

[0011] The present invention provides a method and system for actively detecting the control system status of a coal-fired power unit. A detection and verification logic is newly added on the basis of the original control system, and the operation results of the control logic in the real-time comparison and status detection system are detected to detect network security attack events such as tampering with the control logic and tampering with the control protection parameters.

[0012] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows: A method for actively detecting the state of a control system of a coal-fired power unit comprises the following steps: Step a, connecting the status detection system to each target control system through I / O hard wiring; Step b, actively sending analog and digital signals for verification for each control logic page of each target control system, and returning after calculation by the target control system; Step c: The status detection system comprehensively analyzes the verification results of analog and digital signals to determine the operating status of the control system.

[0013] Furthermore, in step b, the state detection system uses random number operations to generate analog signal outputs, and different control logic pages of different target control systems set different operation logic functions Vn, which are consistent with the detection function Un of the state detection system.

[0014] Furthermore, in step c, the state detection system compares and checks the deviation between the feedback value Vn and the reference value Un in real time. If the deviation value is greater than a set threshold, it is determined that the corresponding control logic page of the control system is abnormal.

[0015] Furthermore, in step b, the state detection system uses a periodic square wave to generate a digital signal output, and the target control system performs an inversion operation on the received digital signal and returns the output to the state detection system.

[0016] Furthermore, in step c, if the digital signal returned by the target control system remains unchanged within 2T, it is determined that the corresponding control logic page of the target control system is abnormal, and T is the square wave generation period of the digital signal of the state detection system.

[0017] Furthermore, in step b, a group of AI / AO, DI / DO detection signals corresponds to a detection of one control logic page of a target control system, and the status detection system accurately locates the fault point according to the control system number and the control logic page number.

[0018] The present invention also proposes an active detection system for the control system status of a coal-fired power unit. The detection system is connected to each target control system, including a CPU module, an AI module, an AO module, a DI module and a DO module. The AO module sends an analog signal for verification to each control logic page of each target control system, and the AI ​​module receives a feedback signal of the target control system to the analog signal; the DO module is used to send a digital signal for verification to each control logic page of each target control system, and the DI module receives a feedback signal of the target control system to the digital signal. The CPU module comprehensively analyzes and determines the operating status of the control system based on the feedback signals of each control logic page of the target control system received.

[0019] Furthermore, the AO channel of the status detection system corresponds to the AI ​​channel of the target control system, and the AI ​​channel of the status detection system corresponds to the AO channel of the target control system; the DO channel of the status detection system corresponds to the DI channel of the target control system, and the DI channel of the status detection system corresponds to the DO channel of the target control system; a set of AI / AO, DI / DO detection signals corresponds to the detection of one of the control logic pages of a target control system.

[0020] Furthermore, the CPU module uses random number calculation to generate analog signals for output, and uses periodic square waves to generate digital signals for output.

[0021] Furthermore, the CPU module determines whether the corresponding control logic page of the target control system is abnormal by comparing in real time whether the deviation between the reference value Un of the status detection system and the feedback value Vn of the target control system meets the set threshold, and by judging whether the digital signal returned by the target control system remains unchanged within a 2-fold square wave generation cycle.

[0022] In summary, the present invention has the following advantages: 1. The state detection system of the present invention is deployed with a dual redundant architecture to ensure that in the event of failure or malfunction of any one of the units, the control system of the coal-fired power unit can still be detected in real time, thereby improving the reliability of the entire state detection system; 2. The state detection system of the present invention uses both analog and digital signal detection, and connects the state detection system and the target control system through I / O hard wiring, thereby reducing the electromagnetic interference between the power plant electronics and the influence of analog signal noise, improving the accuracy and reliability of state detection, and reducing the false alarm rate of detection; 3. The state detection system of the present invention can detect multiple target control systems and multiple control logic pages online at the same time, and each control logic page has a different preset detection logic function, thereby improving the scalability and functionality of the state detection system; 4. The present invention does not change the original control system network architecture, does not implant other software programs in the original control system, by adding detection and verification logic on the basis of the original control system, and real-time comparison and status detection of the operation results of the control logic in the system, so as to discover network security attack events such as tampering with the control logic and tampering with the control protection parameters; 5. The present invention can realize real-time and active detection of the operating status of the control system. If the abnormal status alarm is transmitted to the central control room monitoring system in real time, further analysis can be performed; 6. When any group of AI / AO, DI / DO detection signals are abnormal, the present invention can accurately locate the specific control system number and control logic page number, and accurately locate the fault point. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of a method for using analog signals to perform state detection in the state detection system of the present invention; Figure 2 It is a framework diagram of the state detection system of the present invention; Figure 3 It is a connection diagram of the state control system and the target control system of the present invention. DETAILED DESCRIPTION

[0024] In order to explain the present invention more clearly, the present invention is further described below in conjunction with preferred embodiments and drawings. It should be understood by those skilled in the art that the content described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0025] Example 1 The present invention provides a method for actively detecting the control system status of a coal-fired power unit. The method utilizes the newly added detection and verification logic of the original control system to perform real-time comparison and status detection on the operation results of the control logic in the system, and discover network security attack events such as tampering with the control logic and tampering with the control protection parameters. The method realizes real-time and active detection of the control system operation status without changing the original control system network architecture or implanting other software programs in the original control system, and transmits real-time alarms of abnormal status to the monitoring system of the central control room.

[0026] The core control system of coal-fired power units mainly includes: unit distributed control system (DCS), turbine digital electro-hydraulic control system (DEH), turbine emergency trip system (ETS), boiler furnace safety system (FSS), and generator cooling protection system.

[0027] Among them, the distributed control system (DCS) is the control center of the coal-fired power unit, which uses computer, communication and screen display technology to realize data collection, control and protection functions of the production process.

[0028] The steam turbine digital electro-hydraulic control system (DEH) is an important component of the coal-fired steam turbine generator set and is a regulating controller for the start-up, stop, normal operation and accident conditions of the steam turbine.

[0029] The turbine emergency trip system (ETS) receives the shutdown signal from the local primary / secondary instruments and controls the shutdown solenoid valve to shut down the turbine unit in an emergency to protect the safety of the turbine according to the requirements of safe operation of the turbine.

[0030] The boiler furnace safety system (FSS) is a protection system that prevents unsafe conditions caused by the mixture of fuel and air in the furnace, and can quickly cut off all fuel entering the boiler furnace under critical conditions to prevent destructive accidents such as deflagration and explosion, thereby ensuring the safety of the furnace.

[0031] The generator cooling protection system is a protection system that trips and stops the generator operation in time when it detects that the temperature of core components such as the generator cooler, collector ring, stator core, etc. continues to rise, or that the hydrogen, sealing oil, and cooling water are operating abnormally, which may endanger the safe operation of the generator.

[0032] The control logic of coal-fired power units refers to the logical structure that controls the boiler, steam turbine, and generator set as a whole unit, which mainly includes data acquisition system control logic, analog control system control logic, switch and sequence control system control logic, public control system control logic, etc.

[0033] In order to detect network attacks that tamper with the target control system logic, unauthorized changes to the control system state, or control system failures, it is necessary to detect the controller operation status in real time. The method adopted by the present invention is to add detection logic in the core logic page of the coal-fired power unit control system, and issue an alarm message in time when it is detected that the key logic has been tampered with.

[0034] The principle of the active detection method of the present invention is to use the state detection system to actively send analog and digital signals, which are returned after calculation by the control system, and the calculation results of the target control system are checked online in real time, and compared with the reference value of the state detection system. If the calculation results of the target control system do not meet the expectations, it is judged that an abnormality has occurred in the target control system.

[0035] The state detection system uses random number calculation to generate analog signal output. The principle diagram of the method is shown in Figure 1The state detection system runs a random number generator to generate a random number x. Un=F(x) is a function running in the state detection system. Vn=F(x) is a newly added detection logic function running in the target control system. The state detection system compares and verifies the numerical deviation between the feedback value Vn and the reference value Un of the target control system in real time. Considering the electromagnetic interference between the power plant electronics and the analog signal noise, an over-limit threshold is set. If the deviation value is greater than the set threshold, it is determined that the control system state is abnormal.

[0036] The state detection system uses a square wave of T=1s to generate a digital signal output, that is, the output is 0 for 0-0.5T and 1 for 0.5-1T. The target control system performs an inverse operation on the received digital signal, that is, the received signal is 0 and the output signal is 1, or the received signal is 1 and the output signal is 0. The state detection system detects and verifies in real time. If the returned digital signal remains 1 or 0 for 2T, the control system is judged to be abnormal.

[0037] The present invention provides an active detection method for the control system state of a coal-fired power unit, and the real-time steps are as follows: Step a: Connect the status detection system to each target control system through I / O hard wiring.

[0038] The present invention connects the state detection system and the target control system through I / O hard wiring, reduces the influence of electromagnetic interference between power plant electronics and analog signal noise, and improves the accuracy of state detection. When connected, a set of AI / AO, DI / DO detection signals corresponds to one of the control logic pages of a target control system, and the state detection system can accurately locate the fault point according to the control system number and the control logic page number.

[0039] Step b: Send out analog and digital signals for verification for each control logic page of each target control system, and return after calculation by the target control system.

[0040] In this step, different control logic pages of different target control systems set different operation logic functions V; when performing analog signal verification, the newly added operation logic function V=F(x) of the control logic page of the target control system is kept consistent with the detection function U=F(x) of the state detection system.

[0041] Step c: The status detection system comprehensively analyzes the verification results of analog and digital signals to determine the operating status of the control system.

[0042] In this step, the state detection system compares the deviation between the feedback value Vn of the target control system and the reference value Un of the detection system in real time. If the deviation value is greater than the set threshold, or if the digital signal returned by the target control system remains unchanged at 1 or 0 within 2T (T is the square wave generation period of the digital signal of the state detection system), the corresponding control logic page of the control system is determined to be abnormal.

[0043] The active detection method of the present invention uses analog and digital signal detection at the same time, connects the state detection system and the target control system through I / O hard wiring, reduces the influence of electromagnetic interference between power plant electronics and analog signal noise, and improves the accuracy of state detection.

[0044] Example 2 This embodiment provides an active detection system for the control system status of a coal-fired power unit. The detection system is connected to each target control system, including a CPU module, an AI module, an AO module, a DI module and a DO module, all of which are built on a mature industrial control PLC platform.

[0045] The AO module sends an analog signal for verification to each control logic page of each target control system, and the AI ​​module correspondingly receives a feedback signal of the target control system to the analog signal.

[0046] The DO module is used to send a digital quantity signal for verification to each control logic page of each target control system, and the DI module correspondingly receives a feedback signal of the target control system to the digital quantity signal.

[0047] The CPU module comprehensively analyzes and determines the operating status of the control system based on the feedback signals received from each control logic page of the target control system.

[0048] The state detection system in this embodiment is essentially redundantly deployed, and a single, two, or three state detection systems can be used for detection and verification. Figure 2 The figure shows the deployment of the detection system with dual redundant architecture. The two state detection systems A and B interact with each target control system through I / O hard wiring, and can be configured with a corresponding number of AO / AI and DO / DI hardware channels according to the actual detection needs of the power plant, and expanded to detect N control systems. The state detection system comprehensively analyzes the verification results of analog and digital signals, determines the operating status of the control system, and transmits abnormal status to the power plant control room.

[0049] In this embodiment, a group of AI / AO, DI / DO detection signals corresponds to a control logic page detection of a target control system. The state detection system comprehensively analyzes the verification results of analog and digital signals. If any group of AI / AO, DI / DO detection signals is abnormal, the fault point can be accurately located according to the control system number and the control logic page number. Figure 3 shown.

[0050] When connected, the AO channel of the status detection system corresponds to the AI ​​channel of the target control system, and the AI ​​channel of the status detection system corresponds to the AO channel of the target control system; the DO channel of the status detection system corresponds to the DI channel of the target control system, and the DI channel of the status detection system corresponds to the DO channel of the target control system.

[0051] The CPU module uses random number calculation to generate analog signals for output. It determines whether the corresponding control logic page of the target control system is abnormal by comparing the deviation between the reference value Un of the status detection system and the feedback value Vn of the target control system in real time to see if it meets the set threshold.

[0052] The CPU module uses a periodic square wave to generate a digital signal for output. By judging whether the digital signal returned by the target control system remains unchanged within 2 times the square wave generation period, it can be determined whether the corresponding control logic page of the target control system is abnormal.

[0053] The state detection system of the present invention is deployed with a dual redundant architecture to ensure that in the event of failure or malfunction of any one of the units, the control system of the coal-fired power unit can still be detected in real time, thereby improving the reliability of the entire state detection system.

[0054] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for actively detecting the control system status of a coal-fired power unit, characterized in that: The steps include: Step a, connecting the status detection system to each target control system through I / O hard wiring; Step b, actively sending analog and digital signals for verification for each control logic page of each target control system, and returning after calculation by the target control system; Step c: The status detection system comprehensively analyzes the verification results of analog and digital signals to determine the operating status of the control system.

2. The method for actively detecting the control system status of a coal-fired power unit according to claim 1, characterized in that: In step b, the state detection system uses random number operations to generate analog signal outputs, and different control logic pages of different target control systems set different operation logic functions Vn, which are consistent with the detection function Un of the state detection system.

3. The active detection method of the control system state of a coal-fired power unit according to claim 1 or 2, characterized in that: In step c, the state detection system compares and checks the deviation between the feedback value Vn and the reference value Un in real time. If the deviation value is greater than the set threshold, it is determined that the corresponding control logic page of the control system is abnormal.

4. The method for actively detecting the state of a control system of a coal-fired power unit according to claim 1, characterized in that: In step b, the state detection system uses a periodic square wave to generate a digital signal output, and the target control system performs an inversion operation on the received digital signal and returns the output to the state detection system.

5. The method for actively detecting the state of a control system of a coal-fired power unit according to claim 1 or 4, characterized in that: In step c, if the digital signal returned by the target control system remains unchanged within 2T, it is determined that the corresponding control logic page of the target control system is abnormal, and T is the square wave generation period of the digital signal of the state detection system.

6. The method for actively detecting the control system status of a coal-fired power unit according to claim 1, characterized in that: In step b, a group of analog and digital detection signals corresponds to a control logic page detection of a target control system, and the status detection system accurately locates the fault point according to the control system number and the control logic page number.

7. An active detection system for the control system status of a coal-fired power unit, characterized in that: The detection system is connected to each target control system, including a CPU module, an AI module, an AO module, a DI module and a DO module. The AO module sends an analog signal for verification to each control logic page of each target control system, and the AI ​​module receives the feedback signal of the target control system to the analog signal; the DO module is used to send a digital signal for verification to each control logic page of each target control system, and the DI module receives the feedback signal of the target control system to the digital signal. The CPU module comprehensively analyzes and determines the operating status of the control system based on the feedback signals of each control logic page of the target control system.

8. The active detection system for the control system status of a coal-fired power unit according to claim 7, characterized in that: The AO channel of the status detection system corresponds to the AI ​​channel of the target control system, and the AI ​​channel of the status detection system corresponds to the AO channel of the target control system; the DO channel of the status detection system corresponds to the DI channel of the target control system, and the DI channel of the status detection system corresponds to the DO channel of the target control system; a set of AI / AO, DI / DO detection signals corresponds to the detection of one of the control logic pages of a target control system.

9. The active detection system for the control system status of a coal-fired power unit according to claim 7, characterized in that: The CPU module uses random number calculation to generate analog signals for output, and uses periodic square waves to generate digital signals for output.

10. The active detection system for the control system status of a coal-fired power unit according to claim 7, characterized in that: The CPU module determines whether the corresponding control logic page of the target control system is abnormal by comparing in real time whether the deviation between the reference value Un of the status detection system and the feedback value Vn of the target control system meets the set threshold, and by judging whether the digital signal returned by the target control system remains unchanged within a 2-fold square wave generation cycle.

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