A method, apparatus, computer device, and storage medium for setting signal default values.

Abstract

This invention discloses a method, apparatus, computer device, and storage medium for setting signal default values. The method includes: acquiring a failed target signal in a nuclear power plant's distributed control system; determining the signal type of the target signal by combining redundancy design and functional type; wherein the redundancy design includes single-channel signals and multi-channel signals, and the functional type includes control protection signals and regulation signals; simulating the failure consequences of the target signal under different default values ​​using probabilistic safety analysis based on the signal type; and setting a default value for the target signal based on dynamic default value rules, combining the signal type and the failure consequences. This invention, by comprehensively considering the signal's redundancy design and functional type, and combining dynamic default value rules to set the target signal, can effectively improve the operational safety and reliability of nuclear power units in the event of signal failure.

Description

Technical Field

[0001] This invention relates to the field of nuclear power plant control technology, and in particular to a method, apparatus, computer equipment, and storage medium for setting signal default values. Background Technology

[0002] Distributed Control Systems (DCS) are the core systems for real-time monitoring and control of critical process parameters (temperature, level, pressure, etc.) in nuclear power plants. The I / O processing algorithm in a DCS performs validity checks on all incoming analog and digital signals. When a signal becomes invalid due to reasons such as signal source abnormality, DCS equipment failure, power outage, line fault, sensor / instrument failure, I / O module failure, or process parameters exceeding the instrument's range, the system will determine that the signal is invalid and mark it as a bad value.

[0003] To ensure that the control system can still maintain basic operation and execution logic after a signal failure, DCS default values ​​are usually preset in engineering. When the system detects a signal failure, it automatically replaces the failed signal with the preset value to participate in control.

[0004] Currently, the default values ​​of non-safety-grade DCS signals in nuclear power plants are mostly set based on engineering experience, often using fixed values ​​(such as 0, 1, or the midpoint of the range), without forming a systematic design method. This mainly results in the following shortcomings: Lack of systematic analysis: The comprehensive impact of signal channel type (single-channel, dual-channel, triple-channel), redundancy configuration, safe position of actuators, and signal failure on the safety and economy of the unit is not considered, which can easily lead to control deviations or even safety risks. For example, in a nuclear power plant, if the default value of the VVP103SN signal is set to 1, it may cause excessive steam discharge and lead to overpower risk; if it is set to 0, it may cause turbine damage due to excessive liquid level.

[0005] Insufficient dynamic adaptability: Traditional default values ​​are fixed settings and are not dynamically adjusted based on the effective state before the signal fails. This results in a large deviation from the actual process state and makes it difficult to adapt to different operating conditions of the unit.

[0006] Lack of risk monitoring mechanism: After the signal fails and triggers the default value replacement, there is a lack of targeted process alarms and fault prompts, and operators cannot identify and intervene in a timely manner, which increases the probability of protection function failure.

[0007] Insufficient utilization of redundancy design: The default value settings of redundant signals such as dual-channel 2-out-of-1 and three-channel 3-out-of-2 were not optimized in conjunction with the redundancy degradation mechanism, which reduced the overall fault tolerance and reliability of the system. Summary of the Invention

[0008] This invention provides a method, apparatus, computer device, and storage medium for setting signal default values, aiming to improve the safety and reliability of nuclear power unit operation.

[0009] In a first aspect, embodiments of the present invention provide a method for setting a signal default value, including: Acquire target signals that have failed in the distributed control system of a nuclear power plant; The signal type of the target signal is determined by combining redundancy design and functional type; wherein, the redundancy design includes single-channel signals and multi-channel signals, and the functional type includes control and protection signals and regulation signals; Based on the signal type, the failure consequences of the target signal under different default values ​​are simulated using probabilistic security analysis methods. Based on the signal type and the failure consequences, a default value is set for the target signal according to the dynamic default value rule.

[0010] Secondly, embodiments of the present invention provide a signal default value setting device, comprising: The signal acquisition unit is used to acquire the target signals of failure in the distributed control system of a nuclear power plant; A type determination unit is used to determine the signal type of the target signal by combining redundancy design and functional type; wherein, the redundancy design includes single-channel signals and multi-channel signals, and the functional type includes control protection signals and regulation signals; The failure simulation unit is used to simulate the failure consequences of the target signal under different default values ​​based on the signal type using a probabilistic security analysis method. The default value setting unit is used to set a default value for the target signal based on dynamic default value rules, taking into account the signal type and the failure consequences.

[0011] Thirdly, embodiments of the present invention provide a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the signal default value setting method as described in the first aspect.

[0012] Fourthly, embodiments of the present invention provide a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the signal default value setting method as described in the first aspect.

[0013] This invention provides a method, apparatus, computer device, and storage medium for setting signal default values. The method includes: acquiring a failed target signal in a nuclear power plant's distributed control system; determining the signal type of the target signal by combining redundancy design and functional type; wherein the redundancy design includes single-channel signals and multi-channel signals, and the functional type includes control protection signals and regulation signals; simulating the failure consequences of the target signal under different default values ​​using a probabilistic safety analysis method based on the signal type; and setting a default value for the target signal based on dynamic default value rules, considering both the signal type and the failure consequences. This invention, by comprehensively considering the signal's redundancy design and functional type, and combining dynamic default value rules to set the target signal, effectively improves the operational safety and reliability of nuclear power units in the event of signal failure. This method not only overcomes the limitations of traditional fixed default value setting methods but also comprehensively assesses the potential consequences of signal failure through probabilistic safety analysis, thereby providing a scientific basis for default value selection and improving the operational safety and reliability of nuclear power units. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 A flowchart illustrating a method for setting a signal default value according to an embodiment of the present invention; Figure 2 This is a schematic block diagram of a signal default value setting device provided in an embodiment of the present invention. Detailed Implementation

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0018] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0019] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0020] Please see below. Figure 1 This invention provides a method for setting a signal default value, specifically including steps S101 to S104.

[0021] Step S101: Obtain the target signal that failed in the distributed control system of the nuclear power plant; Step S102: Determine the signal type of the target signal by combining redundancy design and functional type; wherein, the redundancy design includes single-channel signals and multi-channel signals, and the functional type includes control protection signals and regulation signals; Step S103: Based on the signal type, simulate the failure consequences of the target signal under different default values ​​using a probabilistic security analysis method; Step S104: Based on the signal type and the failure consequences, set a default value for the target signal according to the dynamic default value rule.

[0022] In this embodiment, when setting the default value, the target signal that has failed is first obtained. Then, the signal type is determined by combining the redundancy design (i.e., single-channel / multi-channel signal) and the function type (i.e., control protection / regulation signal). Based on the signal type, the failure consequences under different default values ​​are simulated using probabilistic safety analysis methods. Thus, the default value is set for the target signal according to the dynamic default value rules, combining the signal type and failure consequences.

[0023] This embodiment comprehensively considers signal redundancy design and functional types, and combines dynamic default value rules to set target signals, thus effectively improving the operational safety and reliability of nuclear power units in the event of signal failure. This method not only overcomes the limitations of traditional fixed default value settings, but also comprehensively assesses the potential consequences of signal failure through probabilistic safety analysis, providing a scientific basis for default value selection and thereby enhancing the operational safety and reliability of nuclear power units. In practical applications, the default value setting method provided in this embodiment can significantly reduce the probability of maloperation (such as unexpected reactor tripping) or failure to operate (such as protection function failure) caused by signal failure.

[0024] The method for dynamically setting default values ​​of non-safety-grade DCS signals in nuclear power plants provided in this embodiment is based on safety redundancy analysis. Through classification processing, failure impact assessment, and dynamic default value selection, it can solve the problems of insufficient safety and poor adaptability in existing technologies. For example, in the event of a fault in the VVP103SN signal channel of a nuclear power unit, the default value of the VVP103SN signal, set to 1, will cause the VVP718VL signal to be mistakenly opened. This will result in the discharge of some steam from VVP, potentially leading to over-powering of the unit and affecting its thermal efficiency. However, if the default value is 0, the VVP718VL signal will remain closed when the signal fails. If the actual water level of the VVP103PU signal happens to be high at this time, the VVP718VL signal cannot be opened in time, which may cause water accumulation in the pipeline and affect the normal operation of the turbine.

[0025] To address the above issues, this embodiment considers that not only the default values ​​of the aforementioned SN may be set unreasonably, but the default values ​​of other DCS signal channels may also be unreasonably set, which may lead to serious consequences when DCS signals fail. These consequences can cause unexpected power disturbances in the unit or even protection tripping. If the default value is selected incorrectly, it may even further lead to protection degradation failure. Therefore, this embodiment modifies and adjusts unreasonable default values ​​in the field based on the default value setting method to ensure that the impact on the unit, equipment, and personnel is minimized when equipment failure or signal failure occurs.

[0026] In practical applications, the following factors should be considered when setting default values: (1) Whether the signal failure can be monitored by the operators, and how easy or difficult it is to detect the signal failure.

[0027] First, determine if the sensor is displayed on the KIC screen. Second, determine if the instrument or sensor malfunction can be confirmed by comparing the KIC screen or other local sensor / instrument values. Finally, determine if the instrument or sensor malfunction can be determined by the local instrument itself or local signal indicator lights.

[0028] (2) Redundancy of functions of sensors and other equipment.

[0029] The main considerations are whether there are other instrumentation signals to replace the failed instrumentation signals, whether the failed instrumentation signals can be automatically replaced, or whether the functions of the instrumentation signals can be completed manually by controlling the actuator.

[0030] (3) The safe location of the executing agency.

[0031] Consider the actuator's normal operating state and fail-safe position, and whether the default value setting and the safe position are consistent.

[0032] (4) The impact of signal failure.

[0033] Consider the impact and extent of signal failure on the process system. Taking into account the system and unit status, analyze the impact and consequences of losing this function based on the signal's functionality, and qualitatively analyze the scope and consequences of the impact.

[0034] Here, when a signal quality bit is determined to be invalid, the signal can be processed in three ways at the LEVEL layer: First, a default value set by the engineer is used as a replacement; this replacement value must be pre-configured by the engineer in the processing algorithm according to project needs. Second, the most recent valid value is output. Third, the actual channel acquisition value is output. Engineers can choose one of these three methods based on actual project requirements.

[0035] When selecting default values ​​for DCS, the following considerations can be taken into account: For analog signals, consider selecting the low range value, high range value, mid-range value, and last valid value; for switch signals whose faults can be detected by DCS, consider selecting "0", "1", and "last valid value"; for switch signals that cannot be detected by DCS, no default value can be set. Different degrees of rig are needed when selecting default values ​​based on the signal level. Determining the default value is a gradual optimization process, and different analysis perspectives may yield different results. Factors such as unit operation safety, availability, economy, equipment and personnel protection need to be considered, taking into account the possibility of signal failure, to determine the optimal default value.

[0036] In addition, the principles for setting default values ​​are as follows: (a) The optimized default values ​​should not degrade the relevant safety functions and performance of the current unit and system; (b) Categorization analysis: DCS signals are classified into important single-channel pump trip signals, two-out-of-two pump trip signals, three-out-of-two pump / machine trip signals, other machine / reactor trip signals, automatic control signals, etc., and then the default value analysis results are given for each category. (c) Conduct relevant default value analysis based on the existing system design, equipment availability, and on-site feasibility; (d) The selection of default values ​​should minimize modifications to field equipment and be the optimal solution with the least difficulty and risk in field implementation; (e) The analysis should be conducted in terms of functional description, type, category, settable default value, detailed analysis process and analysis results.

[0037] Based on the above analytical principles and requirements, preliminary analytical conclusions can be drawn for the following types of signals. However, specific analysis still requires comprehensive consideration of the process flow, the function of the signal itself, and the impact caused by failure.

[0038] A single-channel signal refers to a signal that controls the action of a single instrument's drive mechanism. It is an independent signal that directly triggers protection or regulation actions (e.g., VVP103SN). For switch signals (i.e., models with control and protection functions), the failure of a single-channel signal will directly lead to malfunctions in the equipment. The default value should be set to a non-operational state to avoid malfunctions. Signal loss means the loss of equipment protection; therefore, important protection signals need to be monitored. Although the DCS system monitors signal validity and triggers corresponding instrumentation and control alarms (I&C) if the signal is invalid, the main control operator's attention to I&C alarms is insufficient. Therefore, a fault process alarm needs to be added so that the main control operator can promptly detect the fault when a channel fails, enabling timely response and preventing the equipment's automatic protection and control functions from being lost for an extended period.

[0039] For analog signals (i.e., signals with a function type of regulation), when a signal fails, the DCS will generally switch from automatic to manual regulation, and the signal will appear as a dashed line on the KIC (Nuclear Power Plant Computer and Control System) screen. Based on practical experience and convention, the default value of the regulation signal can be set to the last valid value to avoid large changes in the regulation output signal caused by sudden changes in the analog value, which could impact the stable operation of the unit. Similarly, a new fault process alarm should be added simultaneously. When a channel fault occurs, the main control operator can promptly detect the fault and respond in a timely manner, preventing the equipment's regulation function from being lost for an extended period.

[0040] For dual-channel signals, depending on the type of switch input, dual-channel signals are divided into 2-out-of-2 protection signals (which use two independent channels for signal acquisition, and the system will only trigger the corresponding protection action when the signals of both channels simultaneously meet the protection triggering conditions) and 2-out-of-1 protection signals (which refer to the same protection parameter using two independent channels for signal acquisition, and the system will trigger the corresponding protection action as long as the signal of either channel meets the protection triggering conditions), such as signals like AHP017SN / AHP018SN.

[0041] Specifically, for the 2-out-of-2 protection signal, if one signal fails, that signal is directly removed, and the protection level is downgraded to 1-out-of-1. If both signals fail simultaneously, the equipment will not operate, thus preventing false activation. A new fault process alarm has been added for timely response.

[0042] For a 2-out-of-1 protection signal, the default value is set to non-operation state. When one signal fails, the other signal participates in the protection. When both signals fail simultaneously, the equipment does not operate, thus preventing malfunction. Therefore, the default value is set to "0". Add a fault process alarm for timely response.

[0043] For analog signals, adjustment strategies such as taking the maximum value, taking the minimum value, and taking the average value can be used. When one signal fails, it is discarded, and adjustment is performed using another signal. When both signals fail, the system switches from automatic to manual setting. In manual setting, the default value of the adjustment signal can be set to the last valid value based on practical experience and convention.

[0044] Three-channel signals refer to redundant protection signals employing a 2-out-of-3 logic, such as the GST003MT.XH01 signal. For switch-type signals within the three-channel configuration, the 2-out-of-3 protection signal features an automatic redundancy degradation mechanism in the DCS system. When a single signal fails, the protection logic degrades to a 1-out-of-2 or 2-out-of-2 mode; when two or more signals fail, the system determines whether to activate the equipment based on the fault mode (e.g., disconnection, exceeding lower limit, exceeding upper limit, etc.). These signals do not have default values, and a new fault process alarm is added for timely response.

[0045] For analog signals, three-channel signals typically use a 3-average adjustment method. When a single signal fails or there is a large deviation between any two signals, the DCS system will automatically discard the abnormal signal and switch to a 2-average adjustment. When two signals fail, the adjustment logic switches to single-channel mode. If all three signals fail simultaneously, it automatically switches to manual adjustment. During manual adjustment, the default value of the adjustment signal can be set to the last valid value, based on practical experience and industry practices.

[0046] In a specific embodiment, setting a default value for the target signal based on dynamic default value rules, in conjunction with the signal type and the failure consequences, includes: When the target signal is a single-channel adjustment signal, the last valid value of the single-channel adjustment signal is set to the default value; When the target signal is a multi-channel adjustment signal, a default value is dynamically set using redundant logic; wherein, the redundant logic includes adjustment by taking the largest value, adjustment by taking the smallest value, and adjustment by taking the average value.

[0047] Based on the above analysis, when the target signal is a regulating signal (i.e., the analog signal mentioned above), for a single-channel signal, the "last valid value" can be used as the default value to avoid sudden changes in the regulating output. If the state before failure is the alarm threshold (such as high liquid level), the alarm state should be maintained to prevent failure to operate.

[0048] For multi-channel signals, default values ​​can be dynamically set using redundant logic. For example, when adjusting the maximum value of a dual-channel signal, the default value of the failed signal can be set to the value of the other channel. Specifically, multi-channel signals can be dual-channel or triple-channel. For a dual-channel 2-out-of-1 signal, the default value of the failed channel can be set to 0, and the protection function can be maintained through redundant channels. For a triple-channel 3-out-of-2 signal, no fixed default value is set; instead, a redundancy degradation mechanism (such as downgrading to 2-out-of-1) is used, while simultaneously triggering a process alarm.

[0049] In another embodiment, setting a default value for the target signal based on a dynamic default value rule, in conjunction with the signal type and the failure consequences, further includes: When the target signal is a single-channel control protection signal, the default value is set to a non-operation state; When the target signal is a multi-channel control protection signal, determine the number of channels of the target signal and set a default value according to the number of channels.

[0050] Specifically, when the target signal is a multi-channel control protection signal, determining the number of channels of the target signal and setting a default value based on the number of channels includes: When the target signal is a dual-channel control and protection signal, a default value is set according to the voting logic of the dual-channel control and protection signal; When the target signal is a three-channel control and protection signal, a non-fixed default value is set for the three-channel control and protection signal based on the redundancy degradation mechanism.

[0051] Furthermore, when the target signal is a dual-channel control protection signal, setting a default value according to the voting logic of the dual-channel control protection signal includes: When the target signal is a dual-channel adjustment signal, the voting type of the dual-channel adjustment signal is determined; wherein, the voting logic includes 2-out-of-1 logic and 2-out-of-2 logic; When the dual-channel adjustment signal is a 2-out-of-1 logic, the default value of the dual-channel adjustment signal is set to 0; When the dual-channel adjustment signal is a 2-out-of-2 logic, if the signal of one channel fails, the failed signal of the corresponding channel is removed; if the signals of both channels fail, a default value is set based on the current state of the target signal.

[0052] In this embodiment, when the target signal is a control protection signal (i.e., the aforementioned switching signal), for a single-channel signal, the default value is set to "non-operational state" (i.e., "0") to prevent false triggering. If the signal was in an operational state (i.e., "1") before failure, it is kept at 1 to avoid failure to operate, and this should be combined with a process alarm.

[0053] For dual-channel signals, based on the above analysis, for 2-out-of-2 protection signals, if one signal fails, it is directly removed, and the protection is downgraded to 1-out-of-1. When both signals fail simultaneously, the equipment does not operate, thus preventing false activation. A new fault process alarm is added for timely response. For 2-out-of-1 protection signals, the default value is set to non-operational state. When one signal fails, the other signal participates in the protection. When both signals fail simultaneously, the equipment does not operate, thus preventing false activation. Therefore, the default value is set to "0". A new fault process alarm is added for timely response.

[0054] For a three-channel 3-out-of-2 signal, no fixed default value is set, and a redundancy degradation mechanism is relied upon (such as downgrading to 2-out-of-1), while triggering a process alarm.

[0055] Furthermore, in this embodiment, when conducting failure impact assessment, the specific characteristics of the process system can be considered to analyze the impact of signal failures on unit safety (such as reactor trip risk), economy (such as thermal efficiency loss), and equipment protection (such as turbine damage probability), forming a quantitative assessment matrix to further optimize the default value setting strategy. Based on the quantitative assessment matrix, and combined with the actual operating conditions of the unit, the impact of different signal failure scenarios is managed in a hierarchical manner. For example, for critical signals that may lead to reactor trip or major equipment damage, priority is given to ensuring that their default value settings can minimize safety risks; while for signals that only affect economy or auxiliary functions, a balance can be sought between safety and availability to reduce interference with the overall system performance.

[0056] Furthermore, the relationship between signal failure detection time and response time must be considered during the default value setting process. For signals that are difficult to detect quickly after failure, special attention should be paid to the selection of their default values ​​to avoid more serious consequences due to delayed response. Simultaneously, to improve system robustness, a dynamic adjustment mechanism can be introduced to automatically optimize the range of default values ​​based on real-time monitored unit status and environmental conditions, thereby better adapting to complex and changing operating scenarios.

[0057] To verify the effectiveness of the default value setting scheme, this embodiment also designed various fault simulation test scenarios. By building a simulation platform in a laboratory environment, the system behavior under different signal failure modes was repeatedly tested to evaluate whether the default value setting could ensure safety while also considering economy and ease of operation. Test results show that the optimized default value setting not only significantly reduced the probability of malfunctions and failures to operate, but also effectively reduced unplanned downtime events caused by signal failures, thereby improving the reliability and stability of the entire system.

[0058] Finally, it is worth noting that default values ​​are not static but need to be continuously updated and iterated upon as operational experience and technology advance. Therefore, it is recommended to establish a regular review mechanism to comprehensively review and adjust existing default values ​​based on historical data and the latest research findings, ensuring they always conform to current best practice standards. Simultaneously, it is crucial to strengthen the training of relevant personnel to ensure they fully understand the logic and principles behind default value settings, enabling them to respond more flexibly to various unforeseen circumstances in actual operation.

[0059] In one embodiment, acquiring the target signal of a failure in the distributed control system of a nuclear power plant includes: When the target signal is detected, an audible and visual alarm is triggered in the main control room to prompt operators to intervene. The target signal is highlighted in the computer and control system screen of the nuclear power plant and associated with auxiliary judgment information of relevant process parameters.

[0060] This embodiment adopts a process alarm coordination mechanism, adding a signal failure process alarm function to the DCS system: when a signal failure is detected, an audible and visual alarm is triggered in the main control room to prompt operators to intervene in a timely manner; at the same time, the failure signal is highlighted in the KIC (Nuclear Power Plant Computer and Control System) screen and associated with relevant process parameters such as liquid level and pressure as auxiliary judgment information, thereby improving the response efficiency of operators to signal failure situations.

[0061] In one embodiment, determining the signal type of the target signal by combining redundancy design and functional type includes: A signal classification database was established based on process drawings and protection logic; The target signal is classified into different types based on the signal classification database.

[0062] In this embodiment, the identification and determination of the target signal type can be achieved by querying a preset signal classification database. This database contains the redundancy design, functional attributes, and corresponding classification information of various signals. After acquiring the target signal, the system automatically matches the records in the database to determine whether the target signal is a single-channel, dual-channel, or triple-channel signal, as well as its specific functional type (such as a protection signal or a regulation signal).

[0063] The following example illustrates the default value setting method described above: (1) Analysis of VVP103SN default value settings VVP103SN is the functional position of a field device, a level switch in the VVP (Main Steam System) system. The consequences of a fault in this signal have been described previously. PSA (Probability of Safety Analysis) calculations show that for the VVP103SN signal, when the default value is "0", the probability of turbine damage due to a high actual condensate level in the steam trap and the inability to open VVP718VL increases by 14%; when the default value is "0", the probability of unit over-powering due to a false opening of the VVP718VL signal even when the actual condensate level is not high increases by 8.05 times. In conclusion, setting the default value to either "0" or "1" has its advantages and disadvantages.

[0064] Therefore, considering both turbine damage and unit over-power scenarios, the default value of the VVP103SN signal can be set to the "last valid value". If the SN status was "0" before the signal failed, it will remain "0" after the signal fails, preventing accidental valve opening and unit over-power. If the SN status was "1" before the signal failed, it will remain "1" after the signal fails, keeping the valve open and preventing high liquid levels from damaging the turbine. A process alarm is also added; when the VVP103SN signal fails, the process alarm will be triggered for timely response.

[0065] (2) Analysis of default value settings for AHP017SN The AHP017SN signal is used to measure the AHP601RE level. When the AHP601RE level is high, it triggers the KA alarm and automatically opens the emergency drain valve AHP118 / 120VL. SN in AHP017SN represents the level switch, and RE in AHP601RE represents the heater. AHP017SN and AHP018SN are redundantly designed; a single SN signal will trigger the valve action.

[0066] When the default value of the AHP017SN signal is 1, if the AHP017SN instrument malfunctions and the actual liquid level of AHP601RE also reaches a high-high value, it will trigger a high-high level alarm for the 6A heater (6A is the power consumption capacity of the heater) and related valve actions together with AHP018SN, without affecting the system. If the actual liquid level is not high-high, this default value will trigger a high-high level alarm for the 6A heater and cause the emergency drain valve to open incorrectly, risking the loss of the AHP601RE heater and affecting the unit's thermal efficiency.

[0067] When the default value of the AHP017SN signal is 0, if the AHP017SN instrument malfunctions, such as when the actual liquid level is too high, the AHP017SN will not trigger a high-high level alarm, nor will it open the emergency drain valve. However, the high-high level switch AHP018SN on another row of liquid level measuring cylinders can trigger a high-high level alarm for the heater and activate the emergency drain valve. Therefore, the default value of "0" for AHP017SN only reduces the redundancy of the 6A heater liquid level measuring switch and has no impact on the system.

[0068] When the default value of the AHP017SN signal is the last valid value, if the liquid level was not high-high before the AHP017SN malfunctions, the AHP017SN will continue to maintain a non-high-high liquid level signal, and the analysis process will be the same as the default value of 0. If the liquid level has already reached the high-high value before the AHP017SN malfunctions, the high-high liquid level signal will be continuously triggered, and the heater will not be able to resume normal operation in time, affecting the unit's thermal efficiency.

[0069] Since AHP017SN has redundant equipment, to avoid the emergency drain valve malfunction affecting unit efficiency, the default value is set to "0", consistent with the current value on site. A new KA alarm for SN failure has also been added to promptly alert the operator when an SN failure occurs.

[0070] (3) Analysis of GST003MT default value settings GST stands for generator stator cooling water system, and MT is a temperature sensor. GST003MT is used to measure the generator stator cooling water temperature. When the temperature exceeds 75℃, it triggers GST012KA. When the temperature exceeds 85℃, it trips the generator protection system in a two-out-of-three configuration with GST004 / 005MT. GST003MT has three signal points that can be set with default values: GST003MT.XQ01, GST003MT.XH03, and GST003MT.XH01. Among them, GST003MT.XQ01 is an analog signal, while GST003MT.XH03 and GST003MT.XH01 are digital signals.

[0071] ① Since GST003MT.XQ01 only displays the temperature value in KIC, no default value is set.

[0072] ② Under normal circumstances, GST003MT.XH03 is used to trigger GST012KA when the temperature is greater than 75℃. Setting the default value of GST003MT.XH03 to "1" will also trigger GST012KA when the GST003MT channel fails, reminding the operator to respond in time.

[0073] ③ GST003MT.XH01 is used for 2 out of 3 trip protection with GST004 / 005MT when the temperature is greater than 85℃. This is because when the GST003MT channel fails, it will not cause the unit to fail to operate or to operate falsely, and its protection can be achieved by the other two channels. Therefore, GST003MT.XH01 does not have a default value.

[0074] In summary, the signal default value setting method provided in this embodiment is the first to combine redundancy design (single / dual / triple channels), functional type (protection / regulation), and quantitative assessment of failure consequences, thereby achieving dynamic priority allocation of signals. Furthermore, when setting default values, strategies such as "last valid value" and conditional 0 / 1 values ​​are proposed to address the disconnect between static default values ​​and dynamic process requirements. A process alarm coordination mechanism is also used to link signal failure alarms with KIC screens and auxiliary parameter prompts, improving human-machine interaction efficiency. Additionally, redundancy degradation collaborative optimization is employed, such as designing a "no fixed default value" strategy for three-channel signals, relying on redundancy degradation mechanisms (e.g., downgrading to 2 out of 1) to avoid disrupting redundant logic.

[0075] Compared to existing technologies, this embodiment achieves the following effects: (1) Improve safety: By assessing the impact of failures and selecting dynamic default values, the probability of false operation (such as unexpected stack jump) or failure to operate (such as protection function failure) caused by signal failure is significantly reduced. (2) Enhance the adaptability of redundant systems: For dual-channel / triple-channel signals, construct a dynamic collaborative redundancy degradation mechanism to avoid fixed default values ​​from destroying redundant logic; (3) Reduce operational risks: The new process alarm mechanism enables operators to respond within 30 seconds after a signal fails, reducing fault handling time by more than 50%; (4) Compatibility and scalability: This method is applicable to different DCS platforms and can be extended to other industrial control fields such as thermal power plants and chemical plants; (5) Economic optimization: Provide standards and methods for setting default values ​​of non-safety level DCS in nuclear power plants, reduce unplanned shutdowns caused by signal failures, and improve the economic efficiency of power generation.

[0076] Figure 2 This is a schematic block diagram of a signal default value setting device 200 provided in an embodiment of the present invention. The device 200 includes: The signal acquisition unit 201 is used to acquire the target signal of failure in the distributed control system of a nuclear power plant. The type determination unit 202 is used to determine the signal type of the target signal by combining the redundancy design and the functional type; wherein, the redundancy design includes single-channel signals and multi-channel signals, and the functional type includes control protection signals and regulation signals; The failure simulation unit 203 is used to simulate the failure consequences of the target signal under different default values ​​based on the signal type using a probabilistic security analysis method. The default value setting unit 204 is used to set a default value for the target signal based on dynamic default value rules, taking into account the signal type and the failure consequences.

[0077] In one embodiment, the default value setting unit 204 includes: The first setting unit is used to set the last valid value of the single-channel adjustment signal to a default value when the target signal is a single-channel adjustment signal. The second setting unit is used to dynamically set a default value using redundant logic when the target signal is a multi-channel adjustment signal; wherein the redundant logic includes adjustment by taking the largest value, adjustment by taking the smallest value, and adjustment by taking the average value.

[0078] In one embodiment, the default value setting unit 204 further includes: The third setting unit is used to set the default value to a non-operation state when the target signal is a single-channel control protection signal; The fourth setting unit is used to determine the number of channels of the target signal when the target signal is a multi-channel control protection signal, and set a default value according to the number of channels.

[0079] In one embodiment, the fourth setting unit includes: A dual-channel setting unit is used to set a default value according to the voting logic of the dual-channel control and protection signal when the target signal is a dual-channel control and protection signal; The three-channel setting unit is used to set a non-fixed default value for the three-channel control and protection signal based on a redundancy degradation mechanism when the target signal is a three-channel control and protection signal.

[0080] In one embodiment, the dual-channel setting unit includes: The voting judgment unit is used to determine the voting type of the dual-channel adjustment signal when the target signal is a dual-channel adjustment signal; wherein the voting logic includes 2-out-of-1 logic and 2-out-of-2 logic; The fifth setting unit is used to set the default value of the dual-channel adjustment signal to 0 when the dual-channel adjustment signal is a 2-out-of-1 logic; The sixth setting unit is used to, when the dual-channel adjustment signal is a 2-out-of-2 logic, if the signal of one channel fails, then the failed signal of the corresponding channel is removed; if the signals of both channels fail, then a default value is set based on the current state of the target signal.

[0081] In one embodiment, the signal acquisition unit 201 includes: An alarm triggering unit is used to trigger an audible and visual alarm in the main control room when the target signal is detected, so as to prompt the operators to intervene. The display association unit is used to highlight the target signal in the computer and control system screen of the nuclear power plant and associate it with auxiliary judgment information of relevant process parameters.

[0082] In one embodiment, the type determination unit 202 includes: The database creation unit is used to create a signal classification database based on process drawings and protection logic; The type classification unit is used to classify the target signal according to the signal classification database.

[0083] Since the embodiments of the apparatus and the embodiments of the method correspond to each other, please refer to the description of the embodiments of the method for the embodiments of the apparatus, which will not be repeated here.

[0084] This invention also provides a computer-readable storage medium storing a computer program thereon, which, when executed, can perform the steps provided in the above embodiments. The storage medium may include various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0085] This invention also provides a computer device, which may include a memory and a processor. The memory stores a computer program, and when the processor calls the computer program in the memory, it can implement the steps provided in the above embodiments. Of course, the computer device may also include various network interfaces, power supplies, and other components.

[0086] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to in the method section. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

[0087] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A method for setting a signal default value, characterized in that, include: Acquire target signals that have failed in the distributed control system of a nuclear power plant; The signal type of the target signal is determined by combining redundancy design and functional type; wherein, the redundancy design includes single-channel signals and multi-channel signals, and the functional type includes control and protection signals and regulation signals; Based on the signal type, the failure consequences of the target signal under different default values ​​are simulated using probabilistic security analysis methods. Based on the signal type and the failure consequences, a default value is set for the target signal according to the dynamic default value rule.

2. The signal default value setting method according to claim 1, characterized in that, The step of setting a default value for the target signal based on dynamic default value rules, taking into account the signal type and the failure consequences, includes: When the target signal is a single-channel adjustment signal, the last valid value of the single-channel adjustment signal is set to the default value; When the target signal is a multi-channel adjustment signal, a default value is dynamically set using redundant logic; wherein, the redundant logic includes adjustment by taking the largest value, adjustment by taking the smallest value, and adjustment by taking the average value.

3. The signal default value setting method according to claim 1, characterized in that, The step of setting a default value for the target signal based on dynamic default value rules, in conjunction with the signal type and the failure consequences, further includes: When the target signal is a single-channel control protection signal, the default value is set to a non-operation state; When the target signal is a multi-channel control protection signal, determine the number of channels of the target signal and set a default value according to the number of channels.

4. The signal default value setting method according to claim 3, characterized in that, When the target signal is a multi-channel control protection signal, determining the number of channels of the target signal and setting a default value based on the number of channels includes: When the target signal is a dual-channel control and protection signal, a default value is set according to the voting logic of the dual-channel control and protection signal; When the target signal is a three-channel control and protection signal, a non-fixed default value is set for the three-channel control and protection signal based on the redundancy degradation mechanism.

5. The signal default value setting method according to claim 4, characterized in that, When the target signal is a dual-channel control protection signal, a default value is set according to the voting logic of the dual-channel control protection signal, including: When the target signal is a dual-channel adjustment signal, the voting type of the dual-channel adjustment signal is determined; wherein, the voting logic includes 2-out-of-1 logic and 2-out-of-2 logic; When the dual-channel adjustment signal is a 2-out-of-1 logic, the default value of the dual-channel adjustment signal is set to 0; When the dual-channel adjustment signal is a 2-out-of-2 logic, if the signal of one channel fails, the failed signal of the corresponding channel is removed; if the signals of both channels fail, a default value is set based on the current state of the target signal.

6. The signal default value setting method according to claim 1, characterized in that, The acquisition of the target signal of failure in the distributed control system of the nuclear power plant includes: When the target signal is detected, an audible and visual alarm is triggered in the main control room to prompt operators to intervene. The target signal is highlighted in the computer and control system screen of the nuclear power plant and associated with auxiliary judgment information of relevant process parameters.

7. The signal default value setting method according to claim 1, characterized in that, The determination of the signal type of the target signal by combining redundancy design and functional type includes: A signal classification database was established based on process drawings and protection logic; The target signal is classified into different types based on the signal classification database.

8. A signal default value setting device, characterized in that, include: The signal acquisition unit is used to acquire the target signals of failure in the distributed control system of a nuclear power plant; A type determination unit is used to determine the signal type of the target signal by combining redundancy design and functional type; wherein, the redundancy design includes single-channel signals and multi-channel signals, and the functional type includes control protection signals and regulation signals; The failure simulation unit is used to simulate the failure consequences of the target signal under different default values ​​based on the signal type using a probabilistic security analysis method. The default value setting unit is used to set a default value for the target signal based on dynamic default value rules, taking into account the signal type and the failure consequences.

9. A computer device, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the signal default value setting method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the signal default value setting method as described in any one of claims 1 to 7.

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