Nuclear power plant seawater pipeline cathodic protection system and output current control method thereof

Abstract

The present application relates to a nuclear power plant seawater pipeline cathodic protection system and its output current control method, comprising: obtaining a first group of monitoring data and a second group of monitoring data; processing the first group of monitoring data and the second group of monitoring data to obtain first preprocessed data, and controlling the output current based on the first preprocessed data; processing the first group of monitoring data and the second group of monitoring data to obtain second preprocessed data, performing fault diagnosis based on the second preprocessed data, and outputting an alarm control signal to trigger an alarm when a fault is determined to occur. The present application uses a plurality of reference potentials weighted average as the control signal of the output current, reduces the false influence of the main reference electrode fault on the system output, and also can realize the fault diagnosis and alarm reminder of the reference electrode, improves the detection ability of the cathodic protection system to the reference electrode fault, and determines the stable operation of the system.

Description

Technical Field

[0001] This invention relates to the field of nuclear power plant subsea pipeline control, and more specifically, to a cathodic protection system for nuclear power plant seawater pipelines and its output current control method. Background Technology

[0002] Seawater circulation pipelines are an important component of coastal nuclear power plants, utilizing seawater to cool waste heat and transfer it to the ocean. These pipelines are quite long, with some employing impressed current cathodic protection reaching lengths of 200-300 meters. Cathodic protection technology is a widely used and effective method for preventing corrosion of metal pipelines. In an impressed current cathodic protection system (CPA system), an applied direct current is used to protect the pipeline, maintaining the potential of the pipeline's inner wall within a certain range, thereby inhibiting corrosion reactions.

[0003] The reference electrode, a crucial component of the CPA system, is used to measure the pipeline's potential value in real time and provide control signals to the cathodic protection power supply. However, in practical applications, the reference electrode may malfunction, leading to distorted measured potential values. Current control methods simply compare the reference potential value acquired by the main reference electrode with the set potential value, adjusting the output based on the difference. This method is highly dependent on the reliability of the main reference electrode, and reference electrode defects are a common type of CPA system failure. When the reference electrode fails, the measured reference potential is not the true potential of the pipeline. While a failure of the auxiliary reference electrode does not affect system control, a failure of the main reference electrode will impact CPA system control, thereby affecting the safe and stable operation of the seawater pipeline. For example, when the main reference electrode fails, the system may output excessive protective current, causing the pipeline's inner wall coating to peel off; or it may output insufficient protective current, leading to pipeline corrosion. These problems severely affect the stable operation and protective effectiveness of the CPA system. Therefore, how to improve the CPA system's ability to detect reference electrode faults and maintain stable system operation when faults occur is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a cathodic protection system for seawater pipelines in nuclear power plants and a method for controlling the output current, addressing the problems existing in the prior art.

[0005] The technical solution adopted by this invention to solve its technical problem is: constructing a method for controlling the output current of a cathodic protection system for seawater pipelines in nuclear power plants, comprising: Acquire a first set of monitoring data and a second set of monitoring data; the first set of monitoring data is the reference potential of the main reference electrode; the second set of monitoring data is the reference potential of multiple auxiliary reference electrodes. The first set of monitoring data and the second set of monitoring data are processed to obtain the first preprocessed data, and the output current is controlled based on the first preprocessed data; The first set of monitoring data and the second set of monitoring data are processed to obtain second preprocessed data. Fault diagnosis is performed based on the second preprocessed data, and an alarm control signal is output to trigger an alarm when a fault is determined to occur.

[0006] In the method for controlling the output current of a cathodic protection system for a seawater pipeline in a nuclear power plant according to the present invention, the step of processing the first set of monitoring data and the second set of monitoring data to obtain the first preprocessed data includes: The first set of monitoring data and the second set of monitoring data are filtered to obtain the maximum and minimum values; The maximum and minimum values ​​are removed to obtain the first preprocessed data.

[0007] In the output current control method of the cathodic protection system for seawater pipelines in nuclear power plants according to the present invention, the step of controlling the output current based on the first preprocessed data includes: The average value of the remaining reference potential is obtained by calculating the mean value based on the first preprocessed data; The output current is controlled based on the average value of the remaining reference potential.

[0008] In the method for controlling the output current of a cathodic protection system for seawater pipelines in a nuclear power plant according to the present invention, controlling the output current based on the average value of the remaining reference potential includes: The average value of the remaining reference potential is compared with the control potential value; If the average value of the remaining reference potential is greater than the control potential value, then the output current is increased; If the average value of the remaining reference potential is less than the control potential value, then the output current is reduced; If the average value of the remaining reference potential is equal to the control potential value, then the output current is controlled to maintain the current value.

[0009] In the output current control method of the cathodic protection system for seawater pipelines in nuclear power plants according to the present invention, the step of processing the first set of monitoring data and the second set of monitoring data to obtain second preprocessed data, performing fault diagnosis based on the second preprocessed data, and outputting an alarm control signal to trigger an alarm when a fault is determined to occur includes: The first set of monitoring data and the second set of monitoring data are filtered to obtain the maximum and minimum values; Obtain the remaining data excluding the maximum and minimum values; The remaining data are averaged to obtain the remaining average value; the maximum value, the minimum value, and the remaining data constitute the second preprocessed data; Fault diagnosis is performed based on the maximum value, the minimum value, and the remaining average value, and an alarm control signal is output to trigger an alarm when a fault is determined to occur.

[0010] In the output current control method for the cathodic protection system of a seawater pipeline in a nuclear power plant according to the present invention, the step of performing fault diagnosis based on the maximum value, the minimum value, and the remaining average value, and outputting an alarm control signal to trigger an alarm when a fault is determined to occur, includes: Calculate the deviation between the maximum value and the remaining average value to obtain a first deviation value; Calculate the deviation between the minimum value and the remaining average value to obtain a second deviation value; Determine whether either the first deviation value or the second deviation value is greater than a set deviation; If so, a fault is detected and an alarm control signal is output to trigger an alarm; If not, no alarm control signal will be output.

[0011] In the output current control method of the cathodic protection system for seawater pipelines in nuclear power plants according to the present invention, the step of processing the first set of monitoring data and the second set of monitoring data to obtain second preprocessed data, performing fault diagnosis based on the second preprocessed data, and outputting an alarm control signal to trigger an alarm when a fault is determined to occur includes: Analyze the average values ​​of the first set of monitoring data and the second set of monitoring data within a preset time period; Fault diagnosis is performed based on the average value within the preset time period, and an alarm control signal is output to trigger an alarm when a fault is detected.

[0012] In the output current control method for the cathodic protection system of a seawater pipeline in a nuclear power plant according to the present invention, the step of performing fault diagnosis based on the average value within the preset time period and outputting an alarm control signal to trigger an alarm when a fault is determined to occur includes: The maximum and minimum average values ​​are obtained by filtering based on the average values ​​within the preset time period. Based on the maximum and minimum average values, determine whether the trend of the average value changes exceeds the fluctuation range; If so, a fault is detected and an alarm control signal is output to trigger an alarm; If not, no alarm control signal will be output.

[0013] This invention also provides a cathodic protection system for seawater pipelines in nuclear power plants, which uses the above-described output current control method for cathodic protection systems for seawater pipelines in nuclear power plants to control the output current, including: The first monitoring unit is used to collect the reference potential of the main reference electrode and obtain the first set of monitoring data. The second monitoring unit is used to collect the reference potential of multiple auxiliary reference electrodes to obtain a second set of monitoring data. The data processing unit is used to process the first set of monitoring data and the second set of monitoring data to obtain first preprocessed data and second preprocessed data; The PLC controller is used to control the output current according to the first preprocessed data, and to perform fault diagnosis according to the second preprocessed data and output an alarm control signal to trigger an alarm when a fault is determined to occur.

[0014] The cathodic protection system for seawater pipelines in nuclear power plants described in this invention also includes: a cathodic protection power supply device and an alarm; The cathodic protection power supply is connected to the PLC controller and is used to output current according to the current control signal of the PLC controller; The alarm is connected to the data processing unit and is used to trigger an alarm based on the alarm control signal output by the data processing unit.

[0015] The cathodic protection system for seawater pipelines in nuclear power plants and its output current control method of the present invention have the following beneficial effects: The system includes: acquiring a first set of monitoring data and a second set of monitoring data; processing the first set of monitoring data and the second set of monitoring data to obtain first pre-processed data, and controlling the output current based on the first pre-processed data; processing the first set of monitoring data and the second set of monitoring data to obtain second pre-processed data, performing fault diagnosis based on the second pre-processed data, and outputting an alarm control signal to trigger an alarm when a fault is detected. The present invention reduces the erroneous impact of main reference electrode faults on the system output by using a weighted average of multiple reference potentials as the control signal for the output current. It also enables fault diagnosis and alarm alerts for the reference electrode, improving the cathodic protection system's ability to detect reference electrode faults and ensuring stable system operation. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1 This is a flowchart illustrating the output current control method for a cathodic protection system of a seawater pipeline in a nuclear power plant provided by the present invention. Figure 2 This is the output control logic diagram of the output current provided by the present invention; Figure 3 This is a schematic diagram of the cathodic protection system for seawater pipelines in nuclear power plants provided by the present invention; Figure 4This is the control logic diagram of the cathodic protection system for seawater pipelines in nuclear power plants provided by the present invention. Detailed Implementation

[0017] 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 embodiments of the present invention, and not all embodiments. 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.

[0018] To address the problem that the current control method for the output current of the cathodic protection system of seawater pipelines in nuclear power plants is highly dependent on the reliability of the main reference electrode, this invention provides a method for controlling the output current of the cathodic protection system of seawater pipelines in nuclear power plants. This method can acquire, compare, and process the reference potential data of multiple reference electrodes, thereby shielding or reducing the adverse effects on the system output when a few reference electrodes experience occasional failures, ensuring that the system output is scientific and effective.

[0019] refer to Figure 1 In a preferred embodiment, the output current control method of the cathodic protection system for seawater pipelines in the nuclear power plant includes steps S10, S20, and S30. Steps S20 and S30 do not have a specific order and can be executed in parallel. The specific execution of each step is as follows: Step S10: Obtain the first set of monitoring data and the second set of monitoring data.

[0020] The first set of monitoring data comprises the reference potential of the main reference electrode; the second set comprises the reference potentials of multiple auxiliary reference electrodes. In specific applications, the first set of monitoring data can be obtained through real-time measurement of the main reference electrode by the first monitoring unit 301. The second set of monitoring data can be obtained through real-time measurement of the main reference electrode by multiple second monitoring units 302. The first monitoring unit 301 and the second monitoring unit 302 can utilize existing potential measurement equipment for monitoring and data acquisition; this invention does not impose specific limitations. The reference electrode refers to the electrode used to measure the potential of the protected structure. Based on the intended use of the measured potential, reference electrodes can be categorized into main reference electrodes and auxiliary reference electrodes.

[0021] Step S20: Process the first set of monitoring data and the second set of monitoring data to obtain the first preprocessed data, and control the output current based on the first preprocessed data.

[0022] In some embodiments, processing the first set of monitoring data and the second set of monitoring data to obtain first preprocessed data includes: filtering the first set of monitoring data and the second set of monitoring data to obtain maximum and minimum values; removing the maximum and minimum values ​​to obtain the first preprocessed data. Controlling the output current based on the first preprocessed data includes: calculating the average value based on the first preprocessed data to obtain the average value of the remaining reference potential; controlling the output current according to the average value of the remaining reference potential.

[0023] The process of controlling the output current based on the average value of the remaining reference potential includes: comparing the average value of the remaining reference potential with the control potential value; if the average value of the remaining reference potential is greater than the control potential value, then increasing the output current; if the average value of the remaining reference potential is less than the control potential value, then decreasing the output current; and if the average value of the remaining reference potential is equal to the control potential value, then controlling the output current to maintain the current value.

[0024] Specifically, firstly, the main reference potential and multiple auxiliary reference potentials are processed to filter out the maximum and minimum values. Then, the filtered maximum and minimum values ​​are removed, and the remaining reference potential data is the first preprocessed data. Next, a weighted average is calculated on the remaining reference potentials to obtain the average value of the remaining reference potentials. Finally, the output current is controlled based on the average value of the remaining reference potentials, that is, the average value of the remaining reference potentials is compared with the control potential value. If the average value of the remaining reference potentials is greater than the control potential value, the output current is increased; if the average value of the remaining reference potentials is less than the control potential value, the output current is decreased; if the average value of the remaining reference potentials is equal to the control potential value, the output current is maintained at the current value. In this embodiment of the invention, the control potential value is a pre-set reasonable potential value, which is mainly used as a reference potential for adjusting the magnitude of the output current. Generally, the control potential value can be -0.8V to -1.05V. It should be noted that in practical applications, the specific step size for increasing or decreasing the output current can be selected according to the actual application, and this invention does not impose specific limitations.

[0025] For example, suppose there is one main reference electrode and seven auxiliary reference electrodes; correspondingly, the main reference potential is V1, the auxiliary reference potentials are V2 to V8, and the control potential value is V0.

[0026] Suppose that the main reference electrode and the first auxiliary reference electrode are faulty, resulting in their potentials being the maximum value Vmax and the minimum value Vmin, respectively; The average potential (i.e., the average value of the remaining reference potential) V = (V3 + V4 + V5 + V6 + V7 + V8) / 6; The average potential V is compared with the control potential value V0. When V is greater than V0, the system increases the output current, and the potential value decreases accordingly. When V is less than V0, the system decreases the output current, and the potential value increases accordingly. When V = V0, the output current remains unchanged. The specific control logic is as follows: Figure 2 As shown. Figure 2 In the diagram, the main reference potential corresponds to V1, the auxiliary reference potential 1 corresponds to V2, the auxiliary reference potential 2 corresponds to V3, the auxiliary reference potential 3 corresponds to V4, the auxiliary reference potential 4 corresponds to V5, the auxiliary reference potential 5 corresponds to V6, the auxiliary reference potential 6 corresponds to V7, and the auxiliary reference potential 7 corresponds to V8.

[0027] When controlling the output current, this invention takes into account that the distorted reference potential collected by a faulty reference electrode will be significantly different from the values ​​measured by other reference potentials. Therefore, it removes the highest value and the lowest value, calculates the average value of the remaining reference potentials, and uses the calculated average value as a control signal to transmit to the power supply device for control. This improves the accuracy and reliability of the output current control and avoids abnormal system output due to reference electrode failure.

[0028] Step S30: Process the first set of monitoring data and the second set of monitoring data to obtain the second preprocessed data, perform fault diagnosis based on the second preprocessed data, and output an alarm control signal to trigger an alarm when a fault is determined to occur.

[0029] In some embodiments, processing the first set of monitoring data and the second set of monitoring data to obtain second preprocessed data, and performing fault diagnosis based on the second preprocessed data and outputting an alarm control signal to trigger an alarm when a fault is determined to occur includes: filtering the first set of monitoring data and the second set of monitoring data to obtain the maximum and minimum values; obtaining the remaining data excluding the maximum and minimum values; calculating the mean of the remaining data to obtain the remaining average value; the maximum value, minimum value, and remaining data constitute the second preprocessed data; performing fault diagnosis based on the maximum value, minimum value, and remaining average value, and outputting an alarm control signal to trigger an alarm when a fault is determined to occur. Specifically, performing fault diagnosis based on the maximum value, minimum value, and remaining average value and outputting an alarm control signal to trigger an alarm when a fault is determined to occur includes: calculating the deviation between the maximum value and the remaining average value to obtain a first deviation value; calculating the deviation between the minimum value and the remaining average value to obtain a second deviation value; determining whether either the first deviation value or the second deviation value is greater than a set deviation; if so, determining that a fault has occurred and outputting an alarm control signal to trigger an alarm; if not, not outputting an alarm control signal.

[0030] Specifically, in this embodiment, the main reference potential and multiple auxiliary reference potentials are first processed to filter out the maximum and minimum values. Then, the remaining reference potentials (i.e., the remaining data) excluding the maximum and minimum values ​​are calculated. Next, the average value of the remaining data is calculated to obtain the remaining average value. The obtained remaining average value and the filtered maximum and minimum values ​​constitute the second preprocessed data. Then, the deviations between the maximum and minimum values ​​and the remaining average value are calculated to obtain the first deviation value and the second deviation value. Finally, the deviation range between the first deviation value, the second deviation value, and the set deviation is used to diagnose whether a fault has occurred. If a fault is determined to have occurred, an alarm control signal is output to trigger an alarm; otherwise, no alarm control signal is output.

[0031] For example, suppose there is one main reference electrode and seven auxiliary reference electrodes; correspondingly, the main reference potential is V1, the auxiliary reference potentials are V2 to V8, and the control potential value is V0.

[0032] Suppose that the main reference electrode and the first auxiliary reference electrode are faulty, resulting in their potentials being the maximum value Vmax and the minimum value Vmin, respectively; Average potential (i.e., residual average value) V = (V3 + V4 + V5 + V6 + V7 + V8) / 6; The deviation between the maximum value Vmax, the minimum value Vmin and the average potential V is calculated in real time. If the difference between the two is significant, a fault is detected, and an alarm control signal is output to trigger an alarm. For example, let the first deviation value be V / Vmax; the second deviation value be Vmin / V; if V / Vmax > 1.1 or Vmin / V > 1.1, a fault is detected, and an alarm is triggered. The value 1.1 is only for illustrative purposes; the specific value can be adjusted according to the actual application.

[0033] This invention calculates the deviation between the maximum, minimum and average values ​​in real time, which can trigger an alarm to remind technicians to verify and handle the problem when a few reference electrodes (such as 1 to 2) malfunction, thus avoiding distortion or abnormality in output current control.

[0034] In some embodiments, processing the first set of monitoring data and the second set of monitoring data to obtain second preprocessed data, and performing fault diagnosis based on the second preprocessed data and outputting an alarm control signal to trigger an alarm when a fault is determined to occur includes: analyzing the average value of the first set of monitoring data and the second set of monitoring data within a preset time period; performing fault diagnosis based on the average value within the preset time period and outputting an alarm control signal to trigger an alarm when a fault is determined to occur. Specifically, performing fault diagnosis based on the average value within the preset time period and outputting an alarm control signal to trigger an alarm when a fault is determined to occur includes: filtering based on the average value within the preset time period to obtain a maximum average value and a minimum average value; determining whether the trend of the average value exceeds the fluctuation range based on the maximum and minimum average values; if so, determining that a fault has occurred and outputting an alarm control signal to trigger an alarm; if not, not outputting an alarm control signal.

[0035] Specifically, in this embodiment, firstly, the first and second sets of monitoring data within a preset time period (e.g., within one hour) are collected and their averages are calculated to obtain multiple average values ​​(e.g., the average value is calculated every minute). Next, the maximum average value (defined as Va) and the minimum average value (defined as Vi) are selected from these multiple average values. Then, the trend of the average value changes within the preset time period is analyzed. If the trend exceeds the fluctuation range, a fault is determined, and an alarm control signal is output to trigger an alarm. For example, the trend of the average potential V within one hour is analyzed; if Vi / Va > 1.2, a fault is determined, and an alarm is triggered. The value 1.2 is only an example; the specific value can be adjusted according to the actual application.

[0036] When multiple reference electrodes (e.g., 6-8) fail, the average potential value will fluctuate significantly. This invention tracks the trend of the average value in real time. If the average value fluctuates by more than a certain percentage within one hour, an alarm will be triggered to remind technicians to verify and handle the issue, thus preventing abnormal or distorted output current control.

[0037] This invention analyzes and processes the potential values ​​measured by the main reference electrode and the auxiliary reference electrode, and then intelligently calculates a reasonable weighted potential value as a control signal. This not only protects the accuracy and reliability of the output current control, but also proactively identifies potential faults in the reference electrode and issues an alarm to remind technicians to verify and handle the possible faults. Moreover, the control signal of this invention is a weighted value of the potentials collected by all reference electrodes. Therefore, even if the main reference electrode fails, the impact on the system output is minimal and can be almost ignored.

[0038] refer to Figure 3The present invention also provides a cathodic protection system for seawater pipelines in nuclear power plants. This cathodic protection system for seawater pipelines in nuclear power plants uses the output current control method for cathodic protection systems for seawater pipelines in nuclear power plants disclosed in the embodiments of the present invention for output current control. The control logic of the cathodic protection system for seawater pipelines in nuclear power plants is as follows: Figure 4 As shown.

[0039] Specifically, such as Figure 3 As shown, the cathodic protection system for the seawater pipelines of this nuclear power plant includes: The first monitoring unit 301 is used to collect the reference potential of the main reference electrode and obtain the first set of monitoring data; The second monitoring unit 302 is used to collect the reference potential of multiple auxiliary reference electrodes to obtain a second set of monitoring data. Data processing unit 303 is used to process the first set of monitoring data and the second set of monitoring data to obtain first preprocessed data and second preprocessed data; The PLC controller 304 is used to control the output current according to the first preprocessed data, and to perform fault diagnosis according to the second preprocessed data and output an alarm control signal to trigger an alarm when a fault is determined to occur.

[0040] Furthermore, the cathodic protection system for the seawater pipeline of the nuclear power plant also includes: a cathodic protection power supply device 305 and an alarm device 306; The cathodic protection power supply device 305 is connected to the PLC controller 304 and is used to output current according to the current control signal of the PLC controller 304. The alarm 306 is connected to the data processing unit 303 and is used to trigger the alarm according to the alarm control signal output by the data processing unit 303.

[0041] Specifically, the specific coordination and operation process between the various units in the cathodic protection system for seawater pipelines in nuclear power plants can be referred to the above-mentioned output current control method for the cathodic protection system for seawater pipelines in nuclear power plants, and will not be repeated here.

[0042] like Figure 4 As shown, all reference potential values ​​are transmitted to the data processing unit 303 (i.e., the data processor). After being processed by the data processing unit 303, the data is transmitted to the PLC controller 304. The PLC controller 304 compares the processed data with the control potential value and controls the output current. At the same time, the data processing unit 303 outputs an alarm control signal to the alarm 306 to control the alarm.

[0043] The invention will now be illustrated with an example.

[0044] The simulation data for the cathodic protection system of the seawater pipeline in the nuclear power plant are shown in Table 1 below: Table 1 Note: The data is for reference only and is not the actual value.

[0045] Control potential value: -0.9V; Protection potential range: -0.8~-1.05V; the protection potential range is the standard specified protection range (relative to the Ag / AgCl electrode). Through automatic adjustment by the cathodic protection power supply device 305, the pipeline reference potential is maintained between -0.80V and -1.05V (relative to the Ag / AgCl electrode). It should be noted that when using Ag / AgCl as the reference electrode, the collected potential value is generally negative.

[0046] ① The main reference electrode and the first auxiliary reference electrode are faulty, resulting in their potentials being -0.82V and -1.03V respectively.

[0047] Traditional method: The system uses main reference potential control. Because the acquired potential value is large, the actual output current of the system is greater than the expected output current, which will cause the coating to detach.

[0048] Using this invention: the average potential V = (-0.94-0.97-0.85-0.93-0.87-0.87) / 6 = -0.905V. The system controls the output current according to -0.905V, reduces the output current, and shields the error caused by the failure of the main reference electrode.

[0049] ②Vmin / V=1.03 / 0.905=1.14>1.1, triggering an alarm to warn that the first auxiliary reference electrode may have malfunctioned.

[0050] V / Vmax=0.905 / 0.82=1.104>1.1, triggering an alarm and indicating that the main reference electrode may be malfunctioning.

[0051] ③ Analyze the range of V changes within one hour. Assume the maximum average value within one hour is -0.82 and the minimum average value is -1.0. -1.0 / -0.82 = 1.22 > 1.2, triggering an alarm and reminding technicians that the average potential value of the system fluctuates greatly and that it is necessary to check whether there are multiple faulty reference electrodes in the system.

[0052] This invention uses the weighted average of multiple reference electrodes as the control signal for the output current of the control system, reducing the erroneous impact of a main reference electrode failure on the system output. Simultaneously, by adding real-time comparison calculations of the maximum, minimum, and average potentials, and analyzing the differences between the maximum, minimum, and average values, the corresponding reference electrodes are analyzed to diagnose potential faults and issue alarms to remind technicians to verify and handle the situation. Furthermore, this invention also includes analysis of the average potential fluctuations over a period of time; if the fluctuation range is large, an alarm is issued to remind technicians to verify and handle the situation.

[0053] 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 apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0054] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0055] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0056] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They do not limit the scope of protection of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should fall within the scope of the claims of the present invention.

Claims

1. A method for controlling the output current of a cathodic protection system for seawater pipelines in a nuclear power plant, characterized in that, include: Acquire the first set of monitoring data and the second set of monitoring data; The first set of monitoring data is the reference potential of the main reference electrode; The second set of monitoring data consists of the reference potentials of multiple auxiliary reference electrodes; The first set of monitoring data and the second set of monitoring data are processed to obtain the first preprocessed data, and the output current is controlled based on the first preprocessed data; The first set of monitoring data and the second set of monitoring data are processed to obtain second preprocessed data. Fault diagnosis is performed based on the second preprocessed data, and an alarm control signal is output to trigger an alarm when a fault is determined to occur.

2. The method for controlling the output current of a cathodic protection system for seawater pipelines in a nuclear power plant according to claim 1, characterized in that, The step of processing the first set of monitoring data and the second set of monitoring data to obtain the first preprocessed data includes: The first set of monitoring data and the second set of monitoring data are filtered to obtain the maximum and minimum values; The maximum and minimum values ​​are removed to obtain the first preprocessed data.

3. The method for controlling the output current of a cathodic protection system for seawater pipelines in a nuclear power plant according to claim 1, characterized in that, The step of controlling the output current based on the first preprocessed data includes: The average value of the remaining reference potential is obtained by calculating the mean value based on the first preprocessed data. The output current is controlled based on the average value of the remaining reference potential.

4. The method for controlling the output current of a cathodic protection system for seawater pipelines in a nuclear power plant according to claim 3, characterized in that, The step of controlling the output current based on the average value of the remaining reference potential includes: The average value of the remaining reference potential is compared with the control potential value; If the average value of the remaining reference potential is greater than the control potential value, then the output current is increased; If the average value of the remaining reference potential is less than the control potential value, then the output current is reduced; If the average value of the remaining reference potential is equal to the control potential value, then the output current is controlled to maintain the current value.

5. The method for controlling the output current of a cathodic protection system for seawater pipelines in a nuclear power plant according to claim 1, characterized in that, The step of processing the first set of monitoring data and the second set of monitoring data to obtain second preprocessed data, performing fault diagnosis based on the second preprocessed data, and outputting an alarm control signal to trigger an alarm when a fault is determined to occur includes: The first set of monitoring data and the second set of monitoring data are filtered to obtain the maximum and minimum values; Obtain the remaining data excluding the maximum and minimum values; The remaining data are averaged to obtain the remaining average value; the maximum value, the minimum value, and the remaining data constitute the second preprocessed data; Fault diagnosis is performed based on the maximum value, the minimum value, and the remaining average value, and an alarm control signal is output to trigger an alarm when a fault is determined to occur.

6. The method for controlling the output current of a cathodic protection system for seawater pipelines in a nuclear power plant according to claim 5, characterized in that, The step of performing fault diagnosis based on the maximum value, the minimum value, and the remaining average value, and outputting an alarm control signal to trigger an alarm when a fault is determined to occur, includes: Calculate the deviation between the maximum value and the remaining average value to obtain a first deviation value; Calculate the deviation between the minimum value and the remaining average value to obtain a second deviation value; Determine whether either the first deviation value or the second deviation value is greater than a set deviation; If so, a fault is detected and an alarm control signal is output to trigger an alarm; If not, no alarm control signal will be output.

7. The method for controlling the output current of a cathodic protection system for seawater pipelines in a nuclear power plant according to claim 1, characterized in that, The step of processing the first set of monitoring data and the second set of monitoring data to obtain second preprocessed data, performing fault diagnosis based on the second preprocessed data, and outputting an alarm control signal to trigger an alarm when a fault is determined to occur includes: Analyze the average values ​​of the first set of monitoring data and the second set of monitoring data within a preset time period; Fault diagnosis is performed based on the average value within the preset time period, and an alarm control signal is output to trigger an alarm when a fault is detected.

8. The method for controlling the output current of a cathodic protection system for seawater pipelines in a nuclear power plant according to claim 7, characterized in that, The step of diagnosing faults based on the average value within the preset time period and outputting an alarm control signal to trigger an alarm when a fault is detected includes: The maximum and minimum average values ​​are obtained by filtering based on the average values ​​within the preset time period. Based on the maximum and minimum average values, determine whether the trend of the average value changes exceeds the fluctuation range; If so, a fault is detected and an alarm control signal is output to trigger an alarm; If not, no alarm control signal will be output.

9. A cathodic protection system for seawater pipelines in a nuclear power plant, comprising output current control using the output current control method for a cathodic protection system for seawater pipelines in a nuclear power plant as described in any one of claims 1-8, characterized in that, include: The first monitoring unit is used to collect the reference potential of the main reference electrode and obtain the first set of monitoring data. The second monitoring unit is used to collect the reference potential of multiple auxiliary reference electrodes to obtain a second set of monitoring data. The data processing unit is used to process the first set of monitoring data and the second set of monitoring data to obtain first preprocessed data and second preprocessed data; The PLC controller is used to control the output current according to the first preprocessed data, and to perform fault diagnosis according to the second preprocessed data and output an alarm control signal to trigger an alarm when a fault is determined to occur.

10. The cathodic protection system for seawater pipelines in nuclear power plants according to claim 9, characterized in that, Also includes: Cathodic protection power supply and alarm; The cathodic protection power supply is connected to the PLC controller and is used to output current according to the current control signal of the PLC controller; The alarm is connected to the data processing unit and is used to trigger an alarm based on the alarm control signal output by the data processing unit.

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