Method and system for improving reliability of thermal engineering three-out-of-two protection logic of thermal power plant

Abstract

The application discloses a method and system for improving reliability of thermal power plant thermal engineering three-out-of-two protection logic, and relates to the technical field of thermal protection logic building, which comprises the following steps: performing over-limit and non-bad quality judgment on signals of measuring points to generate first signals, second signals and third signals; performing bad quality judgment on the signals of the measuring points to generate fourth signals, fifth signals and sixth signals; inputting the fourth signals, the fifth signals and the sixth signals into a three-out-of-two module to generate a seventh signal; inputting the first signals, the second signals, the third signals and the seventh signal into a four-out-of-two module to generate an eighth signal; performing AND operation on the fourth signals, the fifth signals and the sixth signals to generate a ninth signal for detecting complete failure of the measuring points; and performing OR operation on the eighth signal and the ninth signal to generate a tenth signal. The method for improving reliability of thermal power plant thermal engineering three-out-of-two protection logic provided by the application changes the traditional three-out-of-two judgment into four-out-of-two and adds a logic judgment, and can more flexibly cope with measuring point failure conditions.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thermal protection logic building, in particular to a method and system for improving thermal three-out-of-two protection logic reliability of a thermal power plant. BACKGROUND

[0002] The so-called "thermal protection" refers to when an abnormal situation or an accident occurs in a thermal production process, according to the nature and degree of the abnormal situation or the accident, a predetermined processing program is automatically performed on the related system or device to eliminate the abnormality and prevent the accident from expanding, and to ensure the safety of personnel and equipment. According to the object of protection, thermal protection can be generally divided into: unit protection, boiler protection, steam turbine protection, electrical protection, auxiliary machine protection and auxiliary system protection, etc.

[0003] According to the requirements of the industry standard, whether the object of protection is a unit, a boiler, a steam turbine or an auxiliary machine, its protection should adopt a three-measurement-point three-out-of-two logic judgment mode (if there are four measurement points, a four-out-of-two mode is adopted), such as the feedwater flow low protection and the drum water level protection in the main protection of the boiler; the lubricating oil tank liquid level low protection and the EH oil pressure low protection in the main protection of the steam turbine; the water interruption protection in the electrical protection, etc. Most power plants adopt a three-out-of-two judgment mode after comparing the analog signals from three local measurement points with the set value.

[0004] However, due to the non-standard installation of measurement points, unreasonable sampling mode, quality problems of transmitters or maintenance problems, the protection misoperation or refusal caused by measurement point failure often occurs. In addition to ensuring the standard installation of measurement points, reasonable sampling mode, improving the quality of transmitters and strengthening maintenance, the logic reliability needs to be strengthened when the configuration logic is built. SUMMARY

[0005] In view of the above problems, the present application is proposed.

[0006] Therefore, the technical problem solved by the present application is to reduce the probability of protection misoperation or refusal caused by measurement point failure.

[0007] To solve the above technical problems, the present application provides the following technical scheme: a method for improving thermal three-out-of-two protection logic reliability of a thermal power plant, comprising:

[0008] Performing over-limit and non-bad quality judgment on the signals of the three measurement points to generate a first signal, a second signal and a third signal;

[0009] Performing bad quality judgment on the signals of the three measurement points to generate a fourth signal, a fifth signal and a sixth signal;

[0010] Inputting the fourth signal, the fifth signal and the sixth signal into a three-out-of-two module to generate a seventh signal;

[0011] The first signal, the second signal, the third signal and the seventh signal are input into a two-out-of-four module to generate an eighth signal;

[0012] The fourth signal, the fifth signal and the sixth signal are ANDed to generate a ninth signal for detecting complete failure of the measuring point;

[0013] The eighth signal and the ninth signal are ORed to generate a tenth signal.

[0014] As a preferred scheme of the method for improving reliability of thermal three-out-of-two protection logic of a thermal power plant, the out-of-limit and non-bad quality judgment comprises:

[0015] High and low limit amplitude judgment is performed on the analog signals of the three measuring points, and a switching quantity 1 is output when the preset threshold is exceeded, and a switching quantity 0 is output when the preset threshold is not exceeded;

[0016] The analog signals are transmitted to a quality judgment module, and a switching quantity 1 is output if the signal is bad quality, and a switching quantity 0 is output if the signal is good quality;

[0017] The output of the quality judgment module is subjected to a NOT operation, and 1 is converted to 0 and 0 is converted to 1;

[0018] The limit amplitude judgment result and the quality judgment result after the NOT operation are ANDed, and a switching quantity 1 is output when the signal is out of limit and good quality, and a switching quantity 0 is output in other cases;

[0019] Three switching quantity signals are obtained, which are respectively a first signal, a second signal and a third signal.

[0020] As a preferred scheme of the method for improving reliability of thermal three-out-of-two protection logic of a thermal power plant, the bad quality judgment comprises: quality judgment is performed on the analog signals of the three measuring points, a switching quantity 1 is output if the signal is bad quality, and a switching quantity 0 is output if the signal is good quality, and three switching quantity signals are obtained, which are respectively a fourth signal, a fifth signal and a sixth signal.

[0021] The generation of the seventh signal comprises inputting the fourth signal, the fifth signal and the sixth signal into a two-out-of-three module, and when at least two of the three input signals are 1, the seventh signal outputs 1, otherwise 0.

[0022] As a preferred scheme of the method for improving reliability of thermal three-out-of-two protection logic of a thermal power plant, the generation of the eighth signal comprises inputting the first signal, the second signal, the third signal and the seventh signal into a two-out-of-four module, and when at least two of the four input signals are 1, the eighth signal outputs 1, otherwise 0.

[0023] As a preferred scheme of the method for improving reliability of thermal power plant thermal three-out-of-two protection logic, the ninth signal for detecting complete failure of the detection point is generated by inputting the fourth signal, the fifth signal and the sixth signal into an AND module, and when the three input signals are all 1, the ninth signal is output as 1, otherwise 0.

[0024] As a preferred scheme of the method for improving reliability of thermal power plant thermal three-out-of-two protection logic, the tenth signal is generated by inputting the eighth signal and the ninth signal into an OR module, and when either of the eighth signal or the ninth signal is 1, the tenth signal is output as 1, otherwise 0.

[0025] Another object of the present application is to provide a system for improving reliability of thermal power plant thermal three-out-of-two protection logic, which can solve the problems of misoperation and refusal caused by detection point failure in the existing thermal protection system of the thermal power plant, and effectively improve the system reliability and adaptability by constructing a multi-signal redundancy judgment system based on bad quality signals.

[0026] To solve the above technical problems, the present application provides the following technical scheme: a system for improving reliability of thermal power plant thermal three-out-of-two protection logic, comprising: a data input layer, a logic control layer and an output execution layer; the data input layer collects and pre-processes detection point signal data, and transmits the processing results to the logic control layer; the logic control layer performs logic operation processing on the signals of the data input layer, generates signals required by the protection logic, and judges whether the conditions for triggering protection are met; and the output execution layer triggers protection or alarm control according to the output signals of the logic control layer.

[0027] A computer program product comprising a computer program, which, when executed by a processor, implements the steps of the method for improving reliability of thermal power plant thermal three-out-of-two protection logic as described above.

[0028] A computer device comprising a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the method for improving reliability of thermal power plant thermal three-out-of-two protection logic as described above when executing the computer program.

[0029] A computer readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method for improving reliability of thermal power plant thermal three-out-of-two protection logic as described above.

[0030] The method for improving the reliability of thermal power plant thermal three-out-of-two protection logic provided by the application can more flexibly cope with the fault condition of the measuring point by introducing the bad quality signal redundancy judgment, changing the traditional three-out-of-two judgment to four-out-of-two and adding an additional logic judgment. In the case of two measuring point faults, the logic can still normally judge and trigger protection, instead of refusing to act. At the same time, when all the measuring points fail, the system can also shut down or alarm in time to avoid potential harm. The method can select whether to directly shut down or only trigger an alarm when all the measuring points fail, to adapt to the operation needs of different power plants. The optimization logic is based on the improvement of the existing DCS system module and does not require additional hardware, which is convenient for integration and implementation in the existing thermal power plant system. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0032] Figure 1 The overall flowchart of a method for improving the reliability of thermal power plant thermal three-out-of-two protection logic provided by an embodiment of the application.

[0033] Figure 2 The overall structure diagram of a system for improving the reliability of thermal power plant thermal three-out-of-two protection logic provided by an embodiment of the application.

[0034] Figure 3 The first common protection building mode diagram of a method for improving the reliability of thermal power plant thermal three-out-of-two protection logic provided by an embodiment of the application.

[0035] Figure 4 The second common protection building mode diagram of a method for improving the reliability of thermal power plant thermal three-out-of-two protection logic provided by an embodiment of the application.

[0036] Figure 5 The third common protection building mode diagram of a method for improving the reliability of thermal power plant thermal three-out-of-two protection logic provided by an embodiment of the application.

[0037] Figure 6 The optimized protection building mode diagram of a method for improving the reliability of thermal power plant thermal three-out-of-two protection logic provided by an embodiment of the application. DETAILED DESCRIPTION

[0038] In order to make the above objectives, characteristics and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application are described in detail below with reference to the drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should fall within the scope of protection of the present application.

[0039] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in other ways different from those described herein without departing from the scope of the present application, and those skilled in the art can make similar extensions without departing from the concept of the present application, so the present application is not limited to the specific embodiments disclosed below.

[0040] Embodiment 1, reference Figure 1 For an embodiment of the present application, a method for improving the reliability of thermal power plant thermal engineering three-out-of-two protection logic is provided, comprising:

[0041] The signals of the three measuring points are subjected to over-limit and non-bad quality judgment to generate first, second and third signals;

[0042] The signals of the three measuring points are subjected to bad quality judgment to generate fourth, fifth and sixth signals;

[0043] The fourth, fifth and sixth signals are input into a three-out-of-two module to generate a seventh signal;

[0044] The first, second, third and seventh signals are input into a four-out-of-two module to generate an eighth signal;

[0045] The fourth, fifth and sixth signals are ANDed to generate a ninth signal for detecting complete failure of the measuring point;

[0046] The eighth and ninth signals are subjected to OR operation to generate a tenth signal.

[0047] The over-limit and non-bad quality judgment includes:

[0048] The analog signals of the three measuring points are subjected to high and low limit amplitude judgment, and when exceeding the preset threshold, outputting a switching quantity 1, and when not exceeding the preset threshold, outputting a switching quantity 0;

[0049] The analog signals are transmitted to the quality judgment module, and if the signal is bad quality, outputting a switching quantity 1, and if the signal is good quality, outputting a switching quantity 0;

[0050] The output of the quality judgment module is subjected to NOT operation, converting 1 to 0 and 0 to 1;

[0051] The amplitude limiting judgment result is ANDed with the quality judgment result after the NOT operation, and when the signal is over-limited and of good quality, switch quantity 1 is output, otherwise switch quantity 0 is output.

[0052] Three switch quantity signals are obtained, which are a first signal, a second signal and a third signal.

[0053] The bad quality judgment includes: performing quality judgment on the analog quantities of the three measuring points, outputting switch quantity 1 if the signal is of bad quality, outputting switch quantity 0 if the signal is of good quality, and obtaining three switch quantity signals, which are a fourth signal, a fifth signal and a sixth signal.

[0054] The seventh signal is generated by inputting the fourth signal, the fifth signal and the sixth signal into a two-out-of-three module, and when at least two of the three input signals are 1, the seventh signal outputs 1, otherwise 0.

[0055] The eighth signal is generated by inputting the first signal, the second signal, the third signal and the seventh signal into a two-out-of-four module, and when at least two of the four input signals are 1, the eighth signal outputs 1, otherwise 0.

[0056] The ninth signal for detecting complete failure of the measuring point is generated by inputting the fourth signal, the fifth signal and the sixth signal into an AND module, and when the three input signals are all 1, the ninth signal outputs 1, otherwise 0.

[0057] The tenth signal is generated by inputting the eighth signal and the ninth signal into an OR operation module, and when either the eighth signal or the ninth signal is 1, the tenth signal outputs 1, otherwise 0.

[0058] Embodiment 2, refer to Figure 2 An embodiment of the present application provides a system for improving the reliability of thermal three-out-of-two protection logic in a thermal power plant, comprising:

[0059] a data input layer 100, a logic control layer 200 and an output execution layer 300;

[0060] The data input layer 100 collects and pre-processes the measuring point signal data, and transmits the processing results to the logic control layer 200;

[0061] The logic control layer 200 performs logic operation processing on the signals of the data input layer 100, generates signals required by the protection logic, and judges whether the conditions for triggering protection are met;

[0062] The output execution layer 300 triggers protection or alarm control according to the output signal of the logic control layer 200.

[0063] The data input layer 100 includes an input collection module 101, an amplitude limiting judgment module 102 and a quality judgment module 103.

[0064] The logic control layer 200 comprises a NOT module 201, a logic operation module 202, a two-out-of-three module 203, a four-out-of-six module 204, an AND module 205 and an OR module 206.

[0065] The output execution layer 300 comprises an alarm control module 301.

[0066] The data input layer 100 is responsible for collecting and preliminarily processing the signals of measuring points, generating signals for amplitude limiting judgment and quality judgment, and transmitting the signals to the logic control layer.

[0067] The logic control layer 200 completes the logic processing of the signals, generates various signals, and finally outputs the seventh signal for protection triggering.

[0068] The output execution layer 300 triggers the protection control based on the state of the seventh signal, realizes the safety protection of the equipment in the thermal power plant, and improves the reliability of the system.

[0069] Embodiment 3

[0070] An embodiment of the present application is different from the first two embodiments in that:

[0071] If the functions are realized in the form of software function units and sold or used as independent products, the functions can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application or the parts of the technical solutions that essentially contribute to the prior art can be embodied in the form of software products, and the computer software products are stored in a storage medium, including a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in the embodiments of the present application. The foregoing storage medium includes a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various program code storage media.

[0072] The logic and / or steps represented in the flow diagrams or otherwise described herein, for example, can be considered as a sequence of executable instructions, and can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. Just as an example, "computer-readable medium" can be any medium that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-readable medium can be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection (electronic) having one or more wires, a portable computer diskette (magnetic), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber (optical), and a portable compact disc read-only memory (CDROM). Note that the computer-readable medium can even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, for example via an optical scanner, then compiled, interpreted, or otherwise processed, and stored in a computer memory in a form that can be later executed.

[0073] More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection (electronic) having one or more wires, a portable computer diskette (magnetic), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber (optical), and a portable compact disc read-only memory (CDROM). Note that the computer-readable medium can even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, for example via an optical scanner, then compiled, interpreted, or otherwise processed, and stored in a computer memory in a form that can be later executed.

[0074] It should be understood that aspects of the application can be implemented in hardware, software, firmware or combinations thereof. In the above embodiments, various steps or methods can be implemented in software or firmware that is stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, any of the following techniques, which are known in the art, and combinations thereof, can be used: a hybrid of the techniques mentioned above, discrete logic circuit(s) having logic gates for implementing logic functions upon data signals, application specific integrated circuit(s) having appropriate combinational logic gates, programmable gate arrays (PGA), field programmable gate arrays (FPGA), and so forth.

[0075] Through the above description of the embodiments, those skilled in the art can clearly understand that the present application can be realized by means of software and necessary general hardware, and of course can also be realized by hardware, but in many cases the former is a better embodiment. Based on such understanding, the technical solutions of the present application can be embodied in the form of a software product, and the computer software product can be stored in a computer readable storage medium, such as a floppy disk, a read-only memory (ROM), a random access memory (RAM), a FLASH, a hard disk or an optical disk, etc., and includes a number of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods of various embodiments of the present application.

[0076] Embodiment 4, refer to Figures 3-5 For an embodiment of the present application, a method for improving the reliability of thermal power plant thermal engineering three-out-of-two protection logic is provided, comprising:

[0077] Taking the low protection of the lubricating oil tank level of the steam turbine as an example:

[0078] Figure 3 For the common three-out-of-two protection building mode 1, three lubricating oil tank level measuring points from the site are taken, the median value is taken, and then compared with the set value, if it is lower than the set value, the protection is triggered. Among them, the three-out-of-two module is usually a DCS self-contained module, with bad quality judgment, deviation large judgment function, when one measuring point is bad, the logic of the remaining two good points is two-out-of-two, when two points are bad, the logic of the remaining one good point is two-out-of-two. The shortcomings of this logic are: (1) usually the result after the three-out-of-two module is also used for unit analog quantity regulation, in the running, according to the needs of the scene, a certain point may be selected to be fixed as the value after three-out-of-two, if the sampling of the fixed point suddenly leaks or the transmitter suddenly fails, the measured result may become 0 or a very small value, and then the protection may be misoperated. (2) if one of the three measuring points is a bad point and is excluded, the logic is changed to two-out-of-two, and one of the points is a good point but the measurement is inaccurate, becoming a maximum or minimum value, the result after two-out-of-two is also a maximum or minimum value, and then the protection may be misoperated or refused. As can be seen, this three-out-of-two mode instead of three-out-of-two building mode has a great risk of misoperation and refusal.

[0079] Figure 4The common three-out-of-two protection is built in mode 2, three-out-of-two triggers protection after three from local lubricating oil tank level measuring points are compared with fixed value. The main disadvantage of this logic is no measuring point quality judgment: (1) if any one of the three measuring points is bad quality, the measured result becomes small value, then the remaining two measuring points, any one point is disturbed with fluctuation or measuring point fault, all have the possibility to cause protection misoperation. (2) when two measuring points are bad quality, if two measuring points all become small value, the protection directly misoperation; if two measuring points all become large value, even the third measuring point is good point and the measured oil tank level is lower than the protection value, the protection is also refused to operate; if two measuring points one becomes large value and one becomes small value, the third point is disturbed with fluctuation, the protection misoperation. In summary, this building mode also has great misoperation and refusal risk.

[0080] Figure 5 The common three-out-of-two protection is built in mode 3, three-out-of-two triggers protection after three from local lubricating oil tank level measuring points are good quality and lower than limit value. Compared with mode 2, although mode 3 increases the measuring point quality judgment, reduces the probability of protection misoperation, but increases the probability of protection refusal. When one point is bad quality, the point is excluded, the protection logic changes into two-out-of-two; when two points are bad quality, the two points are excluded, the protection logic changes into one-out-of-two, then never triggers, which causes protection refusal. It can be seen that although the quality judgment is increased, when two points are bad quality, the risk of protection refusal is increased.

[0081] In order to reduce the probability of protection misoperation or refusal caused by measuring point fault, improve the reliability of thermal three-out-of-two protection logic in thermal power plant, the present application adopts the following technical scheme (such as Figure 6 ):

[0082] S1, bad quality judgment is carried out on original three measuring points, each measuring point is out of limit value and non-bad quality is used for participating in protection logic;

[0083] The original three measuring points (1-0, 2-0, 3-0) are analog signals, the signals (1-1, 2-1, 3-1) are output, the analog signals are judged by high-low limit amplitude modules (1-2, 2-2, 3-2) and then output on-off quantity 1 or 0 (1-3, 2-3, 3-3). The analog signals are judged by quality modules (1-4, 2-4, 3-4) and then output on-off quantity 1 or 0 (1-5, 2-5, 3-5), wherein 1 represents bad quality and 0 represents good quality. Then the signals are judged by non-module (1-6, 2-6, 3-6) and then output on-off quantity 1 or 0 (1-7, 2-7, 3-7). 1-3 (2-3, 3-3) and 1-7 (2-7, 3-7) signals are judged by and module 1-8 (2-8, 3-8) and then output on-off quantity 1 or 0 (S1-1, S1-2, S1-3).

[0084] S2, the original three measuring points bad quality signal three two selected as the fourth point to participate in the protection logic;

[0085] The original three measuring points bad quality signal as shown in Figure 6 1-5, 2-5, 3-5 (connected to S2-1, S2-2, S2-3) are three inputs of the two module S2, and when two inputs of the three input signals of the two module are 1, the output is 1, and the output signal is S2-4.

[0086] S3, the original two three judgment is changed to two four judgment;

[0087] Compared with the traditional scheme (4 in Figure 5 ), S3 in the present scheme is a two four module. The four inputs of the two four module are S1-1, S1-2, S1-3 and S2-4, and when two inputs of the four input signals of the two four module are 1, the output is 1.

[0088] S4, the original three measuring points bad quality signal is selected as the fifth signal;

[0089] The original three measuring points bad quality signal as shown in the figure is 1-5, 2-5, 3-5 (connected to S4-1, S4-2, S4-3) as three inputs of the and module S4, and when three inputs of the three input signals of the and module are all 1, the output is 1, and the output signal is S4-4.

[0090] S5, the result of S3 is or with the result of S4 as the final protection signal.

[0091] The result S3-1 of S3 and the result S4-4 of S4 are or module S5 to obtain the last protection trigger signal S5-1.

[0092] Compared with the prior art, the present application has the following technical effects:

[0093] When one analog measuring point is bad, the logic is converted to two two; when two analog measuring points are bad, the logic is converted to one one; when three analog measuring points are bad, the protection is directly triggered.

[0094] As can be seen, the three two configuration logic of the present application, when two measuring points are bad, the remaining one measuring point still plays a protection role, which can prevent the harm caused by protection refusal. When three measuring points are bad, it is equivalent to that DCS loses control of monitoring this parameter, and directly trips and stops. Whether to directly trip and stop when three points are bad can be selected according to the specific situation of the power plant, and the present application only provides a configuration method when direct tripping and stopping is needed, and if direct tripping and stopping is not needed, it can be used only for first alarm.

[0095] Example 5, refer toFigures 3-5 For an embodiment of the present application, a method for improving the reliability of thermal power plant thermal engineering three-out-of-two protection logic is provided. In order to verify the beneficial effects of the present application, scientific demonstration is carried out through simulation experiments.

[0096] Experimental conditions: three lubricating oil level analog measurement points are provided.

[0097] Experimental requirements: build a lubricating oil tank liquid level low protection logic, protection action when the liquid level is lower than 1000mm, and try to reduce the risk of protection misoperation and refusal.

[0098] Experiment 1: take Figure 5 The traditional three-out-of-two protection logic is built in the form of three.

[0099] (1) When the three measurement points (lubricating oil tank liquid level measurement points 1-3) are all good points, the lubricating oil tank liquid level measurement point 1 (block 1-0) measurement value is 980mm, the lubricating oil tank liquid level measurement point 2 (block 2-0) measurement value is 990mm, and the lubricating oil tank liquid level measurement point 3 (block 3-0) measurement value is 1003mm.

[0100] ① Block 1-0 passes through comparison module 1-1 with the result of 1; Block 1-0 passes through bad quality judgment module 1-2 with the result of 0, and then passes through NOT module 1-3 with the result of 1; The above two output results pass through AND block 1-4 with the result of 1, which is input 1 of module 4;

[0101] ② Block 2-0 passes through comparison module 2-1 with the result of 1; Block 2-0 passes through bad quality judgment module 2-2 with the result of 0, and then passes through NOT module 2-3 with the result of 1; The above two output results pass through AND block 2-4 with the result of 1, which is input 2 of module 4;

[0102] ③ Block 3-0 passes through comparison module 3-1 with the result of 0; Block 3-0 passes through bad quality judgment module 3-2 with the result of 0, and then passes through NOT module 3-3 with the result of 1; The above two output results pass through AND block 3-4 with the result of 0, which is input 3 of module 4;

[0103] ④ Block 4 is a three-out-of-two module, when two of the three inputs are 1, the output result is 1. In this experiment, two of the inputs of block 4 are 1, so the output result is 1.

[0104] Experimental results: when the three measurement points are all good quality, the protection logic result can be correctly output.

[0105] (2) When the lubricating oil tank liquid level measurement points 1 and 2 are good points, and the lubricating oil tank liquid level measurement point 3 is a bad point, the lubricating oil tank liquid level measurement point 1 (block 1-0) measurement value is 980mm, the lubricating oil tank liquid level measurement point 2 (block 2-0) measurement value is 990mm, and the lubricating oil tank liquid level measurement point 3 (block 3-0) measurement value is 0mm.

[0106] ① Block 1-0 passes through comparison module 1-1 and the result is 1; Block 1-0 passes through bad quality judgment module 1-2 and the result is 0, then passes through NOT module 1-3 and the result is 1; the above two output results pass through AND module 1-4 and the result is 1, which is input 1 of module 4;

[0107] ② Block 2-0 passes through comparison module 2-1 and the result is 1; Block 2-0 passes through bad quality judgment module 2-2 and the result is 0, then passes through NOT module 2-3 and the result is 1; the above two output results pass through AND module 2-4 and the result is 1, which is input 2 of module 4;

[0108] ③ Block 3-0 passes through comparison module 3-1 and the result is 1; Block 3-0 passes through bad quality judgment module 3-2 and the result is 1, then passes through NOT module 3-3 and the result is 0; the above two output results pass through AND module 3-4 and the result is 0, which is input 3 of module 4;

[0109] ④ Block 4 is a three-input majority module, when two of the three inputs are 1, the output result is 1. In this experiment, two of the inputs of block 4 are 1, so the output result is 1.

[0110] Experimental results: when one of the three measuring points is a bad quality and the other two are good quality, the protection logic is equivalent to the two-input majority of the remaining two good points, and when the lubricating oil tank liquid level is lower than 1000mm, the protection logic result can still be output correctly.

[0111] (3) When the lubricating oil tank liquid level measuring point 1 is a good point, and the lubricating oil tank liquid level measuring points 2 and 3 are bad points, the measurement value of the lubricating oil tank liquid level measuring point 1 (block 1-0) is 980mm, the measurement value of the lubricating oil tank liquid level measuring point 2 (block 2-0) is 0mm, and the measurement value of the lubricating oil tank liquid level measuring point 3 (block 3-0) is 0mm.

[0112] ① Block 1-0 passes through comparison module 1-1 and the result is 1; Block 1-0 passes through bad quality judgment module 1-2 and the result is 0, then passes through NOT module 1-3 and the result is 1; the above two output results pass through AND module 1-4 and the result is 1, which is input 1 of module 4;

[0113] ② Block 2-0 passes through comparison module 2-1 and the result is 1; Block 2-0 passes through bad quality judgment module 2-2 and the result is 1, then passes through NOT module 2-3 and the result is 0; the above two output results pass through AND module 2-4 and the result is 0, which is input 2 of module 4;

[0114] ③ Block 3-0 passes through comparison module 3-1 and the result is 1; Block 3-0 passes through bad quality judgment module 3-2 and the result is 1, then passes through NOT module 3-3 and the result is 0; the above two output results pass through AND module 3-4 and the result is 0, which is input 3 of module 4;

[0115] ④ Block 4 is a three-to-two module, when two of the three inputs are 1, the output result is 1. In this experiment, the input of block 4 is all 0, so the output result is 0.

[0116] Experimental results: when two of the three measuring points are bad quality and the other one is good quality, the protection logic is equivalent to one-to-two of the remaining good point, and the protection cannot be triggered. When the lubricating oil tank liquid level is lower than 1000mm, the protection refuses to act, and the protection can never be triggered.

[0117] (4) When the lubricating oil tank liquid level measuring points 1-3 are all bad quality, the lubricating oil tank liquid level measuring point 1 (block 1-0) measured value is 0mm, the lubricating oil tank liquid level measuring point 2 (block 2-0) measured value is 0mm, and the lubricating oil tank liquid level measuring point 3 (block 3-0) measured value is 0mm.

[0118] ① Block 1-0 passes through the comparison module 1-1, the result is 1; block 1-0 passes through the bad quality judgment module 1-2, the result is 1, and then passes through the inverting module 1-3, the result is 0; the above two output results pass through the AND block 1-4, the result is 0, which is input 1 of module 4;

[0119] ② Block 2-0 passes through the comparison module 2-1, the result is 1; block 2-0 passes through the bad quality judgment module 2-2, the result is 1, and then passes through the inverting module 2-3, the result is 0; the above two output results pass through the AND block 2-4, the result is 0, which is input 2 of module 4;

[0120] ③ Block 3-0 passes through the comparison module 3-1, the result is 1; block 3-0 passes through the bad quality judgment module 3-2, the result is 1, and then passes through the inverting module 3-3, the result is 0; the above two output results pass through the AND block 3-4, the result is 0, which is input 3 of module 4;

[0121] ④ Block 4 is a three-to-two module, when two of the three inputs are 1, the output result is 1. In this experiment, the input of block 4 is all 0, so the output result is 0.

[0122] Experimental results: when the three measuring points are all bad quality, when the lubricating oil tank liquid level is lower than 1000mm, the protection refuses to act, and the protection can never be triggered.

[0123] Experiment 2: with the scheme of the present application to build protection logic. Figure 6

[0124] (1) When the three measuring points (lubricating oil tank liquid level measuring points 1-3) are all good points, the lubricating oil tank liquid level measuring point 1 (block 1-0) measured value is 980mm, the lubricating oil tank liquid level measuring point 2 (block 2-0) measured value is 990mm, and the lubricating oil tank liquid level measuring point 3 (block 3-0) measured value is 1003mm.​

[0125] ①S1 module logic judgment and the same as experiment 1, no longer described, S1-1 results for 1, S1-2 results for 1, S1-3 results for 0.

[0126] ②S2-1 results for 0, S2-2 results for 0, S2-3 results for 0, the above three signals through the three S2 module results for 0, S2-4 results for 0.

[0127] ③S1-1, S1-2, S1-3, S2-4, the four signals through the four S3 module results for 1, S3-1 results for 1.

[0128] ④S4-1 results for 0, S4-2 results for 0, S4-3 results for 0, the above three signals through the S4 module results for 0, S4-4 results for 0.

[0129] ⑤S3-1, S4-4, the two signals through the S5 module results for 1.

[0130] Experimental results: when the three measuring points are good quality, the protection logic result can be output correctly.

[0131] (2) when the lubricating oil tank liquid level measuring point 1, 2 is good point, lubricating oil tank liquid level measuring point 3 is bad point, lubricating oil tank liquid level measuring point 1 (block 1-0) measured value is 980 mm, lubricating oil tank liquid level measuring point 2 (block 2-0) measured value is 990 mm, lubricating oil tank liquid level measuring point 3 (block 3-0) measured value is 0 mm.

[0132] ①S1 module logic judgment and the same as experiment 1, no longer described, S1-1 results for 1, S1-2 results for 1, S1-3 results for 0.

[0133] ②S2-1 results for 0, S2-2 results for 0, S2-3 results for 1, the above three signals through the three S2 module results for 0, S2-4 results for 0.

[0134] ③S1-1, S1-2, S1-3, S2-4, the four signals through the four S3 module results for 1, S3-1 results for 1.

[0135] ④S4-1 results for 0, S4-2 results for 0, S4-3 results for 1, the above three signals through the S4 module results for 0, S4-4 results for 0.

[0136] ⑤S3-1, S4-4, the two signals through the S5 module results for 1.

[0137] The experimental results show that when one of the three measuring points is of bad quality and the other two are of good quality, the protection logic is equivalent to two out of two of the remaining two good points, and when the lubricating oil tank liquid level is lower than 1000mm, the protection logic result can still be output correctly.

[0138] (3) When the lubricating oil tank liquid level measuring point 1 is a good point and the lubricating oil tank liquid level measuring points 2 and 3 are bad points, the measuring value of the lubricating oil tank liquid level measuring point 1 (block 1-0) is 980mm, the measuring value of the lubricating oil tank liquid level measuring point 2 (block 2-0) is 0mm, and the measuring value of the lubricating oil tank liquid level measuring point 3 (block 3-0) is 0mm.

[0139] ① The logic judgment in the S1 module is the same as that in the experiment 1, and is not described again. The S1-1 result is 1, the S1-2 result is 0, and the S1-3 result is 0.

[0140] ② The S2-1 result is 0, the S2-2 result is 1, and the S2-3 result is 1. The above three signals pass through the two out of three module S2, and the S2 result is 1. The S2-4 result is 1.

[0141] ③ The S1-1, S1-2, S1-3 and S2-4 signals pass through the four out of five module S3, and the S3 result is 1. The S3-1 result is 1.

[0142] ④ The S4-1 result is 0, the S4-2 result is 1, and the S4-3 result is 1. The above three signals pass through the AND module S4, and the S4 result is 0. The S4-4 result is 0.

[0143] ⑤ The S3-1 and S4-4 signals pass through the OR module S5, and the S5 result is 1.

[0144] The experimental results show that when two of the three measuring points are of bad quality and the other one is of good quality, the protection logic is equivalent to one out of one of the remaining one good point, and when the lubricating oil tank liquid level is lower than 1000mm, the protection can still be triggered correctly.

[0145] (4) When the lubricating oil tank liquid level measuring points 1-3 are all of bad quality, the measuring value of the lubricating oil tank liquid level measuring point 1 (block 1-0) is 0mm, the measuring value of the lubricating oil tank liquid level measuring point 2 (block 2-0) is 0mm, and the measuring value of the lubricating oil tank liquid level measuring point 3 (block 3-0) is 0mm.

[0146] ① The logic judgment in the S1 module is the same as that in the experiment 1, and is not described again. The S1-1 result is 0, the S1-2 result is 0, and the S1-3 result is 0.

[0147] ② The S2-1 result is 1, the S2-2 result is 1, and the S2-3 result is 1. The above three signals pass through the two out of three module S2, and the S2 result is 1. The S2-4 result is 1.

[0148] ③S1-1, S1-2, S1-3, S2-4, four signals pass through the four-to-two module S3, the result is 0, S3-1 result is 0.

[0149] ④S4-1 result is 1, S4-2 result is 1, S4-3 result is 1, the above three signals pass through the AND module S4, the result is 1, S4-4 result is 1.

[0150] ⑤S3-1, S4-4, two signals pass through the OR module S5, the result is 1.

[0151] Experimental results: when the three measuring points are bad quality, it is equivalent to DCS monitoring of this parameter out of control, directly trip shutdown. For three points are bad quality, whether directly trip shutdown can be selected according to the specific situation of power plant, the present application only provides the configuration method when the need for direct trip shutdown, if not need to trip shutdown, can be used only for the first alarm.

[0152] Comparing experiment 1 and experiment 2, (1), (2) conditions, two kinds of scheme can correctly trigger protection; (3) condition, the traditional scheme will protect the refusal to move, and the protection scheme of the present application can still be correctly operated according to the actual situation; (4) condition, the traditional scheme will protect the refusal to move, and the protection scheme of the present application can be according to the requirements of the power plant to carry out the first alarm or directly trigger protection. It can be seen that the protection logic reliability built by the scheme of the present application is higher.

[0153] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and not to limit, although the present application 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 application can be modified or replaced by equivalent, without departing from the spirit and scope of the technical solutions of the present application, which should be covered in the scope of the claims of the present application.

Claims

1. A method for improving the reliability of three-out-of-two protection logic in thermal power plants, characterized in that, include: The signals from the three measuring points are judged to be out of limit but not bad quality, and the first signal, the second signal and the third signal are generated. The signals from the three measuring points are judged to have poor quality, and a fourth, fifth, and sixth signal are generated. Input the fourth, fifth, and sixth signals into the 3-out-of-2 module to generate the seventh signal; Input the first, second, third, and seventh signals into the 2-out-of-4 module to generate the eighth signal; The fourth, fifth, and sixth signals are ANDed together to generate the ninth signal, which indicates that the detection point has completely failed. Perform an OR operation on the eighth and ninth signals to generate the tenth signal.

2. The method for improving the reliability of the three-out-of-two protection logic in thermal power plants as described in claim 1, characterized in that: The judgment of out-of-limit but not defective quality includes: The analog signals at three measurement points are subjected to high and low amplitude judgment. When the amplitude exceeds the preset threshold, the switch quantity 1 is output, and when the amplitude does not exceed the preset threshold, the switch quantity 0 is output. The analog signal is transmitted to the quality judgment module. If the signal is of bad quality, the switch quantity 1 is output; if the signal is of good quality, the switch quantity 0 is output. The output of the quality judgment module is NOTed, converting 1 to 0 and 0 to 1. The limiting judgment result is ANDed with the quality judgment result after negation. When the signal exceeds the limit and is of good quality, the switch quantity 1 is output; otherwise, the switch quantity 0 is output. Three switching signals are obtained, namely the first signal, the second signal, and the third signal.

3. The method for improving the reliability of the three-out-of-two protection logic in thermal power plants as described in claim 2, characterized in that: The bad quality judgment includes: judging the quality of the analog quantity at three measuring points; if the signal is of bad quality, output switch quantity 1; if the signal is of good quality, output switch quantity 0, and obtain three switch quantity signals, namely the fourth signal, the fifth signal and the sixth signal. The generation of the seventh signal involves inputting the fourth, fifth, and sixth signals into a 2-out-of-3 module. When at least two of the three input signals are 1, the seventh signal is output as 1; otherwise, it is output as 0.

4. The method for improving the reliability of the three-out-of-two protection logic in thermal power plants as described in claim 3, characterized in that: The generation of the eighth signal involves inputting the first, second, third, and seventh signals into a 2-out-of-4 module. When at least two of the four input signals are 1, the eighth signal is output as 1; otherwise, it is output as 0.

5. The method for improving the reliability of the three-out-of-two protection logic in thermal power plants as described in claim 4, characterized in that: The generation of the ninth signal indicating that the detection point has completely failed includes inputting the fourth, fifth, and sixth signals into an AND module. When all three input signals are 1, the ninth signal is output as 1; otherwise, it is output as 0.

6. The method for improving the reliability of the three-out-of-two protection logic in thermal power plants as described in claim 5, characterized in that: The generation of the tenth signal involves inputting the eighth and ninth signals into the OR operation module. When either the eighth or the ninth signal is 1, the tenth signal is output as 1; otherwise, it is output as 0.

7. A system employing the method described in any one of claims 1 to 6 for improving the reliability of the three-out-of-two protection logic in thermal power plants, characterized in that, include: The system comprises a data input layer (100), a logic control layer (200), and an output execution layer (300). The data input layer (100) collects and preprocesses the measurement point signal data, and transmits the processing results to the logic control layer (200); The logic control layer (200) performs logical operations on the signals from the data input layer (100) to generate the signals required for the protection logic and determine whether the conditions for triggering protection are met. The output execution layer (300) triggers protection or alarm control based on the output signal of the logic control layer (200).

8. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the steps of the method for improving the reliability of the thermal power plant's three-out-of-two protection logic as described in any one of claims 1 to 6.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method for improving the reliability of the thermal power plant's three-out-of-two protection logic as described in any one of claims 1 to 6.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the method for improving the reliability of the thermal power plant's three-out-of-two protection logic as described in any one of claims 1 to 6.

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