Reliability evaluation method and system for control rod control clamping piece

Abstract

The invention relates to the field of reliability evaluation of rod control clamping pieces, in particular to a reliability evaluation method and system for a control rod control clamping piece, and the method comprises the steps: 1, screening out key sensitive components of the rod control clamping piece; 2, forming a performance index matrix of the key sensitive component, and obtaining a degradation rule of the performance indexes of the key sensitive component; 3, dividing a functional area of the rod control clamping piece; step 4, obtaining a fault mode of the functional area and an influence relation between the functional areas through analogue simulation, and performing arrangement to obtain a state criterion index matrix of the rod control card; 5, carrying out an electric heating combined accelerated aging test on the rod control clamping piece, correcting the state criterion index matrix of the rod control clamping piece, and obtaining an overall performance degradation rule model of the rod control clamping piece; and step 6, by measuring the parameters of the rod control clamping piece, diagnosing the reliability of the rod control clamping piece and evaluating the service life of the rod control clamping piece. According to the method, key output characteristic indexes and sensitive device performance indexes of the card are fused, and a card health state evaluation system based on multi-dimensional indexes is constructed.

Description

Technical Field

[0001] This invention relates to the field of reliability assessment of control rods, and in particular to a method and system for reliability assessment of control rods. Background Technology

[0002] The main function of the control rod control card in a reactor pressure vessel is to convert regulation signals and transformer synchronization signals into thyristor control signals through circuit calculations, controlling the raising and lowering of the control rods. This is a crucial guarantee for the safe and reliable operation of nuclear power plants. In recent years, with the extension of the unit's service life, the aging and failure of the control rod cards have led to increasingly obvious abnormalities in unit operation, attracting high attention from the Nuclear Safety Administration and power plant operators.

[0003] Currently, the maintenance strategy for rod control cards mainly involves replacement after failure. Existing technologies lack effective means of assessing the condition of rod control cards for regular inspection; they also cannot track their aging status and establish corresponding status indicators to carry out preventive maintenance or replacement, which not only affects the reliability of equipment operation but also has low economic efficiency. Summary of the Invention

[0004] This invention provides a reliability assessment method and system for control rod control cards, addressing the problem of the lack of regular monitoring methods for control rod control cards in the prior art.

[0005] The technical solution of the present invention is as follows:

[0006] This invention proposes a reliability assessment method for control rod control cards. This method enables condition diagnosis and lifespan assessment of the control rod control cards. The method includes:

[0007] Step 1: Based on the failure rate of general components in the rod control card, identify the key sensitive components of the rod control card;

[0008] Step 2: Conduct electrothermal accelerated aging tests on key sensitive components. During the aging test, monitor the performance indicators of key sensitive components to form a performance indicator matrix of key sensitive components and obtain the degradation pattern of the performance indicators of key sensitive components.

[0009] Step 3: Divide the functional areas of the rod control card according to the processing flow of the electrical signals of the rod control module;

[0010] Step 4: Perform simulation modeling based on the functional areas of the control card, using the degradation law of key sensitive components as input, and obtain the failure modes of the functional areas and the influence relationship between the functional areas through simulation, and compile the state judgment index matrix of the control card.

[0011] Step 5: Conduct an accelerated aging test combining electrothermal and thermal aging on the rod control card, compare the test results with the simulation results, correct the state criterion index matrix of the rod control card obtained from the simulation results, and obtain the overall performance degradation law model of the rod control card based on the test results.

[0012] Step Six: Diagnose the reliability of the rod control card by measuring its parameters and referring to the corrected state criterion matrix of the rod control card. Evaluate the lifespan of the rod control card by referring to the degradation law of the performance indicators of key sensitive components and the overall performance degradation law model of the rod control card.

[0013] In some embodiments, the key sensitive components in step one include capacitors, inductors, diodes, and field-effect transistors.

[0014] In some embodiments, the performance indicators of key sensitive components in step two include the capacitance and equivalent series impedance of capacitors, the equivalent series resistance of inductors, the forward voltage drop of diodes, and the low-frequency transconductance of field-effect transistors.

[0015] In some embodiments, the degradation law of performance indicators in step two is obtained by fitting the performance indicators and aging time to obtain the degradation law formula.

[0016] In some embodiments, the functional area of ​​step three includes a voltage regulator circuit, a comparator circuit, and a thyristor phase control circuit.

[0017] In some embodiments, the degradation patterns of key sensitive component performance indicators include the variation of electrolytic capacitor capacitance with aging period, the variation of electrolytic capacitor equivalent series impedance with aging period, the variation of inductor equivalent series resistance with aging period, the variation of diode forward voltage drop with aging period, and the variation of MOSFET low-frequency transconductance with aging period; the overall performance degradation model of the control card specifically includes the degradation pattern of control card output pulse with aging period, the degradation pattern of control card output pulse total width with aging period, and the degradation pattern of control card output square wave width with aging period.

[0018] This invention proposes a reliability evaluation system for control rod control card components. The system includes a display, an industrial computer, an Ethernet network, and a rod control card component measuring device. The display is connected to the industrial computer, and the industrial computer is connected to the rod control card component measuring device via the Ethernet network.

[0019] In some embodiments, the rod control card measurement device includes an electronic load, a waveform generator, a multimeter, an oscilloscope, an LCR meter, a switch matrix, a power supply, and a fixture. The power supply includes AC and DC power supplies. The fixture is used to hold different test rod control card output ports and intermediate test points, and to transmit electrical signals from the rod control card. The switch matrix is ​​connected to the electronic load, waveform generator, multimeter, oscilloscope, LCR meter, and power supply. The switch matrix is ​​used to switch circuits according to different test requirements. The power supply provides power input to the rod control card, the waveform generator provides signal input to the rod control card, the electronic load provides analog output to the rod control card, and the multimeter, oscilloscope, and LCR meter acquire the performance parameters of the rod control card.

[0020] In some embodiments, the industrial control computer has built-in reliability assessment software for control rod control cards. The assessment software includes a driver module, a communication module, a storage module, an execution module, a design module, a monitoring module, and an analysis and management module. The driver module is used to control the measurement device of the control rod control card; the communication module is used to control the Ethernet and transmit information between devices; the design module is used to design the test process, algorithm, criteria, and safety interlocks of the control rod control card; the execution module drives the driver module and the communication module to perform the designed control rod control card test according to the test process of the design module; the retrieval module is used to monitor the parameters of the test process and obtain test data; the storage module is used to store the test data and test process of the control rod control card; the analysis and management module has built-in a modified state criterion index matrix of the control rod control card, the degradation law of the performance index of key sensitive components, and the overall performance degradation law model of the control rod control card for the reliability assessment method of the control rod control card. The analysis and management module reads the test data from the storage module to diagnose the reliability of the control rod control card and assess its lifespan.

[0021] In some embodiments, the system's rod control card testing includes rod control card adjustment capability testing, rod control card output waveform testing, rod control card load testing, rod control card key point testing, and rod control card key component testing.

[0022] The following benefits can be obtained by implementing this invention.

[0023] 1. This invention proposes a reliability assessment method for control rod control cards. This method integrates key output characteristic indicators of the card and performance indicators of sensitive devices, and constructs a card health status evaluation system based on multi-dimensional indicators. The method includes fault diagnosis and status assessment algorithms, and is applied to the reliability detection and evaluation system of control rod control cards.

[0024] 2. This invention proposes a reliability assessment system for control rod control cards. The system has a built-in configurable test matrix, supports automated testing of all parameters of domestically produced control rod control cards, and a single card test takes less than 3 minutes. This system can quickly and comprehensively test the performance of domestically produced control rod control system cards, improving the efficiency and accuracy of testing; assess the current aging status and remaining lifespan of the cards; and identify and analyze fault conditions, providing a basis for the implementation of preventative maintenance measures. Attached Figure Description

[0025] Figure 1 This is a flowchart of a reliability assessment method for a control rod control card according to an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram illustrating the capacitance degradation law of a reliability evaluation method for a control rod control card according to an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram illustrating the degradation law of the equivalent series impedance of capacitors in a reliability evaluation method for a control rod control card proposed in an embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram illustrating the degradation law of the inductor equivalent resistance in a reliability assessment method for a control bar controller proposed in an embodiment of the present invention.

[0029] Figure 5 This is a schematic diagram illustrating the degradation law of diode forward voltage drop in a reliability evaluation method for a control bar controller proposed in an embodiment of the present invention.

[0030] Figure 6 This is a schematic diagram illustrating the low-frequency transconductance degradation law of a field-effect transistor in a reliability evaluation method for a control rod-type control card according to an embodiment of the present invention.

[0031] Figure 7 This is a schematic diagram illustrating the degradation law of the total width of the output pulse of the control board in a reliability evaluation method for a control bar control card proposed in an embodiment of the present invention.

[0032] Figure 8 This is a schematic diagram illustrating the degradation law of the output pulse cycle of a control board in a reliability evaluation method for a control bar control card according to an embodiment of the present invention.

[0033] Figure 9 This is a schematic diagram illustrating the degradation law of the output square wave width in a reliability evaluation method for a control rod control card according to an embodiment of the present invention.

[0034] Figure 10 This is a schematic diagram of a hardware system for a reliability evaluation system for a control bar controller according to an embodiment of the present invention;

[0035] Figure 11 This is a software system diagram of a reliability evaluation system for a control rod control card according to an embodiment of the present invention; Detailed Implementation

[0036] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. 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.

[0037] like Figures 1 to 9 As shown, this invention proposes a reliability evaluation method for control rod control cards, the method comprising:

[0038] Step 1: Based on the experience of statistical analysis of common component failures in rod control cards, the key sensitive components of the rod control cards to be evaluated are initially screened and identified, including electrolytic capacitors, inductors, diodes, field-effect transistors, etc.

[0039] Step Two: As Figures 2 to 6 As shown, an accelerated aging test combining electrothermal and thermal methods was conducted on key sensitive components. During the aging test, the performance indicators of these components were monitored, including the capacitance and equivalent series impedance of capacitors, the equivalent series resistance of inductors, the forward voltage drop of diodes, and the low-frequency transconductance of field-effect transistors. A performance indicator matrix was constructed by monitoring these indicators. By fitting the performance indicators to the aging time, a degradation law formula was obtained, which represents the degradation law of the key sensitive components' performance indicators. This includes the changes in capacitance, equivalent series impedance, equivalent series resistance, forward voltage drop, and low-frequency transconductance of the diodes over the aging period.

[0040] Step 3: Based on the processing flow of the electrical signals of the rod control module, divide the functional areas of the rod control card to be evaluated, specifically into voltage regulation circuit, comparator circuit, thyristor phase control circuit, etc.

[0041] Step 4: Perform simulation modeling based on the functional areas of the control module to be evaluated. Using the degradation patterns of key sensitive components as input, obtain the fault mode characterization of the functional areas and the influence relationships between functional areas through simulation, and obtain the state criterion index matrix for evaluating the control module, as shown in Table 1 below. The specific simulation method involves changing the parameter values ​​of key sensitive components, comparing the simulation results with those of the simulation software, and compiling the state criterion index matrix for evaluating the control module, which serves as the diagnostic method and criterion index for the control module to be evaluated.

[0042] Table 1 Criterion Index Matrix for Domestic Rod Control Cards

[0043]

[0044]

[0045] Step 5: Conduct an accelerated aging test combining electrothermal and thermal aging on the control card to be evaluated. Compare the test results with the simulation results, correct the state criterion index matrix of the control card obtained from the simulation results, and obtain the overall performance degradation law model of the control card based on the test results, as detailed below. Figures 7 to 9 As shown, this specifically includes the degradation law of the output pulse of the rod control card board with the aging cycle, the degradation law of the total width of the output pulse of the rod control card board with the aging cycle, and the degradation law of the width of the output square wave of the rod control card with the aging cycle.

[0046] Step Six: By measuring the parameters of the control rod card, and referring to the modified state criterion matrix of the control rod card, the reliability of the control rod card is diagnosed. The lifespan of the control rod card is evaluated by referring to the degradation patterns of performance indicators of key sensitive components and the overall performance degradation pattern model of the control rod card. Simultaneously, based on the reliability assessment method for control rod cards developed above, a card testing and evaluation system is built to perform performance testing on in-service control rod cards, achieving fault diagnosis and lifespan assessment of the control rod cards.

[0047] like Figure 10 As shown, this invention proposes a reliability evaluation system for control rod control cards. The system includes a display, an industrial computer, an Ethernet network, and a control rod control card measuring device. The display is connected to the industrial computer, and the industrial computer is connected to the control rod control card measuring device via the Ethernet network. The display is used for result display and test process control, as well as the transmission of control signals and test results. The operator controls the industrial computer through the display, thereby evaluating the reliability of the control rod control card by manipulating the control rod control card measuring device and power supply. The Ethernet network is used to control the communication between the industrial computer and the control rod control card measuring device.

[0048] The measuring device for the control rod includes an electronic load, a waveform generator, a multimeter, an oscilloscope, an LCR meter (inductance, capacitance, and resistance tester), a switch matrix, a power supply, and fixtures. The power supply includes both AC and DC power. The fixtures are used to hold the output ports and intermediate test points of different control rods and transmit the electrical signals from the control rods. The switch matrix is ​​connected to the electronic load, waveform generator, multimeter, oscilloscope, LCR meter, and power supply. The switch matrix is ​​used to switch circuits according to different testing requirements and control the power supply to the electronic load, waveform generator, multimeter, oscilloscope, and LCR meter. The monitor and industrial computer control the electronic load, waveform generator, multimeter, oscilloscope, LCR meter, switch matrix, and power supply via Ethernet. Among them, the electronic load is used to test the output capability of the rod control card; the waveform generator is used to provide the synchronization signal for the rod control card; the multimeter is used to collect the rated value of the bias voltage of the rod control card; the oscilloscope is used to collect the waveform characteristics output by the rod control card under different bias voltages and different triangular wave peak amplitudes, including phase difference, waveform amplitude, waveform frequency, duty cycle, waveform width, etc.; and the LCR meter is used to collect the key components and impedance of the rod control card.

[0049] When the system hardware is working, the industrial control computer controls the corresponding switches of other components in the matrix to perform closing / closing actions via Ethernet. The industrial control computer controls the power supply to provide power input to the rod control card, controls the waveform generator to provide signal input to the rod control card, controls the electronic load to provide analog output to the rod control card, and controls the multimeter, oscilloscope and LCR meter to collect relevant performance parameters of the rod control card. The test fixture is used to fix the card under test and transmit its electrical signals.

[0050] like Figure 11As shown, to enable the hardware system to function, the industrial control computer incorporates reliability assessment software for the control rod controller. This software includes a driver module, a communication module, a storage module, an execution module, a design module, a monitoring module, and an analysis and management module. The driver module controls the control rod controller's measuring device; the communication module transmits information between devices via Ethernet; the design module designs the control rod controller's testing process, algorithms, criteria, and safety interlocks; the execution module drives the driver and communication modules to perform the designed control rod controller tests according to the design module's test process; the retrieval module monitors the test parameters and acquires test data; the storage module stores the control rod controller's test data and test process; and the analysis and management module contains a modified state criterion index matrix for the control rod controller's reliability assessment method, the degradation law of key sensitive component performance indicators, and a model of the overall performance degradation law of the control rod controller. The analysis and management module reads the test data from the storage module to diagnose the reliability of the control rod controller and assess its lifespan. During testing, this software is installed on an industrial control computer. The linkage between the software modules is as follows: 1) Before use, the user compiles information such as process flow, control, and safety interlocks in the design module; 2) During testing, the execution module performs relevant actions through the communication module and driver module hardware devices, displays the corresponding test status on the monitor, and stores the test results in the storage module; 3) After the test, the test data from the storage module is called to evaluate the status of the card, including determining whether the card is faulty, assessing the remaining lifespan of the card, and outputting relevant management measures for the corresponding status.

[0051] The specific testing of the system's control card includes:

[0052] 1. Test of the adjustability of the control lever.

[0053] A DC power supply powers the rod control card, a waveform generator inputs a synchronization signal to the rod control card, an oscilloscope acquires the amplitude of the triangular wave from the rod control card, and a multimeter acquires the bias amplitude of the rod control card. The oscilloscope also acquires the output pulse waveform of the rod control card. Software is used to plot the relationship curves between the triangular wave amplitude, bias amplitude, synchronization signal, and pulse waveform; the linearity of the curves characterizes the adjustment capability of the rod control card.

[0054] 2. Test of output waveform of rod control card

[0055] A DC power supply powers the rod control card, a waveform generator inputs a synchronization signal to the rod control card, an oscilloscope acquires the amplitude of the triangular wave from the rod control card, and a multimeter acquires the bias amplitude of the rod control card. The oscilloscope also acquires the output pulse waveform of the rod control card. Software displays the pulse waveform and calculates its amplitude, frequency, duty cycle, and width.

[0056] 3. Load testing of the control card

[0057] A DC power supply powers the rod control card, a waveform generator inputs a synchronization signal to the rod control card, the output signal of the rod control card is connected to the load, and the output pulse train signal of the rod control card controls the on and off of the thyristor, thereby controlling the on and off of the load circuit. The load-carrying capacity of the rod control card is characterized by testing the magnitude of the output voltage and the load current.

[0058] 4. Testing of key points of the control card

[0059] The DC power supply powers the rod control card, the waveform generator inputs a synchronization signal to the rod control card, the oscilloscope acquires the waveforms of the input and output points of the integrated chip of the rod control card, the software displays the waveforms and compares them with previous waveforms in the system database to determine whether the waveform is distorted; at the same time, it judges whether the waveform amplitude, duty cycle, period, bandwidth and other parameters are abnormal, and then identifies whether each module of the rod control card is normal.

[0060] 5. Testing of key components in rod control cards

[0061] A DC power supply powers the rod control card, and a waveform generator inputs a synchronization signal to the rod control card. An LCR meter measures the electrical performance parameters of key components in each functional module of the rod control card. For electrolytic capacitors, the capacitance, equivalent series resistance, dielectric loss, and phase angle are measured; for inductors, inductance, quality factor, and impedance are measured. Software records these values, and the impedance test results are compared with the nominal values. Based on the deviation falling within three different ranges, the components under test are judged to be in healthy, degraded, or faulty states, respectively. See Table 1 for the criteria index matrix of domestic rod control cards. Combined with the degradation law of key sensitive component performance indicators and the overall performance degradation law model of the rod control card, calculations and analyses are performed to predict the lifespan of the rod control card based on the components.

[0062] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A reliability assessment method for a control rod control card, characterized in that, The method enables condition diagnosis and lifespan assessment of the control card, and the method includes: Step 1: Based on the failure rate of general components in the rod control card, identify the key sensitive components of the rod control card; Step 2: Conduct an accelerated aging test combining electrothermal and thermal methods on the key sensitive components. During the aging test, the performance indicators of the key sensitive components are detected to form a performance indicator matrix of the key sensitive components and obtain the degradation law of the performance indicators of the key sensitive components. Step 3: Divide the functional areas of the rod control card according to the processing flow of the electrical signals of the rod control module; Step 4: Perform simulation modeling based on the functional areas of the control card, using the degradation law of key sensitive components as input, and obtain the failure modes of the functional areas and the influence relationship between the functional areas through simulation, and compile the state judgment index matrix of the control card. Step 5: Conduct an accelerated aging test combining electrothermal and thermal aging on the rod control card, compare the test results with the simulation results, correct the state criterion index matrix of the rod control card obtained from the simulation results, and obtain the overall performance degradation law model of the rod control card based on the test results. Step Six: Diagnose the reliability of the rod control card by measuring its parameters and referring to the corrected state criterion matrix of the rod control card. Evaluate the lifespan of the rod control card by referring to the degradation law of the performance indicators of key sensitive components and the overall performance degradation law model of the rod control card.

2. The reliability assessment method for a control rod control card according to claim 1, characterized in that, The key sensitive components in step one include capacitors, inductors, diodes, and field-effect transistors.

3. The reliability assessment method for a control rod control card according to claim 2, characterized in that, The performance indicators of key sensitive components in step two include the capacitance and equivalent series impedance of capacitors, the equivalent series resistance of inductors, the forward voltage drop of diodes, and the low-frequency transconductance of field-effect transistors.

4. The reliability assessment method for a control rod control card according to claim 1, characterized in that, In step two, the degradation law of performance indicators is obtained by fitting the performance indicators and aging time to obtain the degradation law formula.

5. The reliability assessment method for a control rod control card according to claim 1, characterized in that, The functional areas of step three include a voltage regulator circuit, a comparator circuit, and a thyristor phase control circuit.

6. The reliability evaluation method for a control rod control card according to claim 4, characterized in that, The degradation patterns of the performance indicators of the key sensitive components include the changes in capacitance of electrolytic capacitors with aging cycles, the changes in equivalent series impedance of electrolytic capacitors with aging cycles, the changes in equivalent series resistance of inductors with aging cycles, the changes in forward voltage drop of diodes with aging cycles, and the changes in low-frequency transconductance of field-effect transistors with aging cycles. The overall performance degradation model of the rod control card specifically includes the degradation patterns of the output pulses of the rod control card board with aging cycles, the degradation patterns of the total width of the output pulses of the rod control card board with aging cycles, and the degradation patterns of the width of the output square wave of the rod control card with aging cycles.

7. A reliability evaluation system for a control rod control card according to claims 1-6, characterized in that, The system includes a display, an industrial computer, an Ethernet network, and a rod control card measuring device. The display is connected to the industrial computer, and the industrial computer is connected to the rod control card measuring device via Ethernet.

8. A reliability evaluation system for a control rod control card according to claim 7, characterized in that, The rod control card measurement device includes an electronic load, a waveform generator, a multimeter, an oscilloscope, an LCR meter, a switch matrix, a power supply, and a fixture. The power supply includes both AC and DC power supplies. The fixture is used to hold different test rod control card output ports and intermediate test points, and to transmit the electrical signals of the rod control card. The switch matrix is ​​connected to the electronic load, waveform generator, multimeter, oscilloscope, LCR meter, and power supply, and is used to switch circuits according to different test requirements. The power supply provides power input to the rod control card, the waveform generator provides signal input to the rod control card, the electronic load provides analog output to the rod control card, and the multimeter, oscilloscope, and LCR meter acquire the performance parameters of the rod control card.

9. A reliability evaluation system for a control rod control card according to claim 8, characterized in that, The industrial control computer has built-in reliability assessment software for the control rod control card. This software includes a driver module, a communication module, a storage module, an execution module, a design module, a monitoring module, and an analysis and management module. The driver module controls the control rod control card's measuring device; the communication module controls the Ethernet network to transmit information between devices; the design module designs the control rod control card's testing process, algorithms, criteria, and safety interlocks; the execution module drives the driver module and communication module to perform the designed control rod control card tests according to the test process designed by the design module; the retrieval module monitors the parameters of the testing process and acquires test data; the storage module stores the control rod control card's test data and test process; the analysis and management module contains a modified state criterion index matrix for the control rod control card's reliability assessment method, the degradation law of key sensitive component performance indicators, and the overall performance degradation law model of the control rod control card. The analysis and management module reads the test data from the storage module to diagnose the reliability of the control rod control card and assess its lifespan.

10. A reliability evaluation system for a control rod control card according to claim 8, characterized in that, The system's rod control card testing includes rod control card adjustment capability testing, rod control card output waveform testing, rod control card load testing, rod control card key point testing, and rod control card key component testing.

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