Reactor rod position measurement threshold intelligent fitting method

Abstract

The invention belongs to the field of nuclear power stations, and particularly relates to a reactor rod position measurement threshold value intelligent fitting method which comprises the following steps: step 1, acquiring an original rod position measurement signal of a rod position detector; 2, waveform processing is carried out on the collected original rod position measurement signal, and the amplitude waveform of the rod position measurement signal is obtained; step 3, mapping the amplitude waveform of the rod position measurement signal and the given rod position, and obtaining the amplitude range of the amplitude waveform corresponding to the given rod position in each step; step 4, weighting the amplitude range of the amplitude waveform corresponding to the given rod position in each step; and 5, overlapping the amplitude ranges of the amplitude waveforms corresponding to all the given rod positions, and obtaining the amplitude range with the highest weighting coefficient after overlapping, namely the obtained measurement threshold range. The method can effectively improve the accuracy of the measurement threshold, improve the rod position measurement precision and reduce the debugging time of the rod position threshold.

Description

Technical Field

[0001] The invention belongs to the field of nuclear power plants, and in particular relates to an intelligent fitting method for a reactor rod position measurement threshold. Background Art

[0002] The rod cluster control assembly RCCA is located in a high temperature and high pressure environment of the primary circuit, and its position is generally measured using the principle of electromagnetic induction. When the control rod is at different positions in the rod position detector, the inductance of the rod position detector changes, causing the output voltage signal amplitude of the rod position measurement coil to change. When the output voltage amplitude exceeds the measurement threshold, it can be judged that the control rod has reached the measurement coil position, and then the control rod position information can be obtained. The quality of the measurement threshold directly determines the accuracy of the rod position measurement.

[0003] The traditional rod position measurement threshold is obtained by manual groping, that is, the measurement threshold is repeatedly adjusted during the full stroke of the rod, so that all rod position change points meet the design requirements. The traditional rod position measurement threshold acquisition lacks theoretical algorithms, and the threshold accuracy is low, which affects the rod position measurement accuracy; and the control rod needs to move repeatedly, which consumes a lot of time and manpower. Summary of the invention

[0004] The object of the present invention is to provide a reactor rod position measurement threshold intelligent fitting method, which can effectively improve the measurement threshold accuracy, improve the rod position measurement accuracy, and reduce the rod position threshold debugging time.

[0005] The technical solution to achieve the purpose of the present invention is:

[0006] A reactor rod position measurement threshold intelligent fitting method, the method comprising:

[0007] Step 1, collecting the original rod position measurement signal of the rod position detector;

[0008] Step 2: Process the collected original rod position measurement signal to obtain an amplitude waveform of the rod position measurement signal;

[0009] Step 3, mapping the amplitude waveform of the rod position measurement signal and the given rod position to obtain the amplitude range of the amplitude waveform corresponding to each given rod position;

[0010] Step 4, weighting the amplitude range of the amplitude waveform corresponding to each given rod position;

[0011] Step 5: Overlap the amplitude ranges of the amplitude waveforms corresponding to all given rod positions to obtain the amplitude range with the highest weighting coefficient after overlapping, which is the obtained measurement threshold range.

[0012] In step 1, the rod position detector is composed of a primary coil, an auxiliary coil and multiple groups of measuring coils.

[0013] In step 1, the primary coil of the rod position detector receives an AC power supply as its excitation power supply.

[0014] In step 1, when the control rods in the reactor move in the rod position detector, the induced voltage signals of each group of measuring coils are collected, which are the original rod position measurement signals.

[0015] The waveform processing in step 2 includes filtering processing and amplitude calculation.

[0016] The filtering process adopts a low-pass filtering method to filter out frequency interference components other than the AC power supply frequency in the rod position measurement signal.

[0017] The weighting coefficient used in step 4 is determined by the expected stick position boundary point corresponding to a given stick position. The higher the expected boundary point, the larger the value of the weighting coefficient for the amplitude range corresponding to the given stick position.

[0018] The weighting coefficients used in the weighting in step 4 are based on the normal distribution probability.

[0019] When the amplitude ranges of the amplitude waveforms corresponding to all given rod positions are overlapped in step 5, the weighted coefficients of the overlapping parts are added together, and the amplitude with the highest weighted coefficient is the rod position measurement threshold.

[0020] The beneficial technical effects of the present invention are:

[0021] 1. The present invention provides a reactor rod position measurement threshold intelligent fitting method, which obtains a high-quality rod position measurement threshold by performing segmented weighting on the rod position measurement waveform amplitude, amplitude range weight superposition and other processing.

[0022] 2. The invention provides a reactor rod position measurement threshold intelligent fitting method, which greatly improves the accuracy of the rod position measurement threshold and improves the rod position measurement accuracy.

[0023] 3. The intelligent fitting method for reactor rod position measurement threshold provided by the present invention only requires the control rod to run back and forth once, which greatly saves the threshold debugging time, reduces the difficulty of obtaining the rod position threshold, and ensures the safe and reliable operation of the nuclear power plant. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a flowchart of the original rod position measurement signal waveform processing in an embodiment of the present invention;

[0025] Figure 2 is an amplitude waveform diagram of a rod position measurement signal after waveform processing in an embodiment of the present invention;

[0026] Figure 3 Schematic diagram of the mapping between the measured amplitude waveform and the given rod position in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0028] The present invention provides a reactor rod position measurement threshold intelligent fitting method, which specifically includes the following steps:

[0029] Step 1: Collect the original rod position measurement signal of the rod position detector

[0030] The rod position detector consists of a primary coil, an auxiliary coil and multiple groups of measuring coils.

[0031] The primary coil of the rod position detector receives an AC power supply as its excitation power supply.

[0032] When the control rods in the reactor move in the rod position detector, the induced voltage signals of each group of measuring coils are collected, which are the original rod position measurement signals (rod position measurement waveforms).

[0033] Step 2: Process the collected original rod position measurement signal to obtain the amplitude waveform of the rod position measurement signal.

[0034] like Figure 1 As shown, the original rod position measurement signal collected in step 1 is filtered, and the filtering process adopts a low-pass filtering method to filter out the frequency band interference components other than the AC power supply frequency in the rod position measurement signal.

[0035] The amplitude of the rod position measurement signal after filtering is obtained to obtain the amplitude waveform of the rod position measurement signal.

[0036] Step 3: Map the amplitude waveform of the rod position measurement signal to the given rod position to obtain the amplitude range of the amplitude waveform corresponding to each given rod position.

[0037] The amplitude waveform of the rod position measurement signal in step 2 is mapped one by one to the given rod position to obtain the amplitude range of the amplitude waveform corresponding to the given rod position in each step.

[0038] Step 4: Weight the amplitude range of the amplitude waveform corresponding to each given stick position

[0039] The amplitude range of the amplitude waveform corresponding to each given stick position in step 3 is weighted, and the weighting coefficient is determined by the expected stick position boundary point corresponding to the given stick position. The higher the expected boundary point, the larger the weighting coefficient value selected for the amplitude range corresponding to the given stick position.

[0040] In the present invention, the normal distribution probability is used as the weighting coefficient.

[0041] Step 5: Overlap the amplitude ranges of the amplitude waveforms corresponding to all given rod positions to obtain the amplitude range with the highest weighting coefficient after overlapping, which is the obtained measurement threshold range.

[0042] When the amplitude ranges of the amplitude waveforms corresponding to all given rod positions are overlapped, the weighted coefficients of the overlapping parts are added.

[0043] Example

[0044] Taking a rod position measurement waveform output by a set of rod position detector measurement coils as an example, the present invention provides a reactor rod position measurement threshold intelligent fitting method, which specifically includes the following steps:

[0045] Step 1: The primary coil of the rod position detector receives an AC power supply as its excitation power supply. When the control rod moves in the detector, the output voltage signals of each group of measuring coils are collected, which are the original rod position measurement signals.

[0046] Step 2: After filtering and amplitude calculation, the collected original rod position measurement signal is processed to obtain the amplitude waveform of the rod position measurement signal, such as Figure 2 The processing flow is shown in Figure 1 The filtering link adopts low-pass filtering to filter out the interference components of the rod position measurement signal in the frequency band other than the AC power frequency; the amplitude calculation obtains the amplitude of the measured waveform after the filtering link.

[0047] Step 3: Map the amplitude waveform of the rod position measurement signal to the given rod position one by one to obtain the amplitude range corresponding to the given rod position at each step.

[0048] Figure 3 The figure shows a section of the rod position amplitude waveform after processing in step 2. The horizontal axis represents the given rod position value within the total measurement range of the detector (ranging from 0 to the maximum number of control steps), and the vertical axis represents the amplitude of the rod position measurement signal. Figure 3 As shown in the figure, when the given rod position is 45 steps, the amplitude range of the rod position measurement signal amplitude waveform is u1-u2, and when the given rod position is 77 steps, the corresponding amplitude range is u3-u4. Similarly, the amplitude ranges corresponding to all given rod positions within the full range of the control rod stroke are deduced.

[0049] Step 4: Weight the amplitude range corresponding to each given stick position. The higher the expectation of the boundary point appearing at the given stick position, the larger the weighting coefficient of the amplitude range, and vice versa.

[0050] The present invention uses the normal distribution probability as the weighting coefficient, and the values ​​of the standard normal distribution probability as the weighting coefficient from large to small are 0.682, 0.272, 0.042, 0.002 and 0 respectively.

[0051] The given rod positions and corresponding weighting coefficients corresponding to the expected values ​​of the boundary points from high to low are shown in Tables 1 to 4, where N is an integer ranging from 0 to 6.

[0052] Table 1 Weighting coefficient of the rising edge of the rod position measurement signal amplitude when the control rod is lifted

[0053]

[0054] Table 2 Weighting coefficient of the falling edge of the rod position measurement signal amplitude when the control rod is lifted

[0055]

[0056] Table 3 Weighting coefficient of the rising edge of the rod position measurement signal amplitude when the control rod is inserted

[0057]

[0058] Table 4 Weighting coefficient of the falling edge of the rod position measurement signal amplitude when the control rod is inserted

[0059]

[0060] by Figure 3 Taking the waveform shown as an example, the amplitude range corresponding to the given rod positions of 45 steps and 77 steps is weighted. According to Table 1, the weighting coefficients of u1~u2 are M1=0.682 and the weighting coefficients of u3~u4 are M2=0.682.

[0061] Step 5: Overlap the waveform amplitude ranges corresponding to all given rod positions, add the weighted coefficients of the overlapping parts, and obtain the amplitude range with the highest weighted coefficient after overlapping, which is the obtained measurement threshold range.

[0062] by Figure 3 As shown in the figure, the waveform amplitude ranges corresponding to the given stick positions of 45 and 77 are overlapped to form the following amplitude intervals, namely [u1, u3], [u3, u2] and [u2, u4]. Then the weight coefficient of [u1, u3] is M1=0.682, the weight coefficient of [u3~u2] is M1+M2=1.364, and the weight coefficient of [u2~u4] is M2=0.682.

[0063] After the waveform amplitude ranges are superimposed, the amplitude range [u3 to u2] with the highest weight coefficient is the obtained measurement threshold range.

[0064] In the development project of the rod control rod position system for the third-generation nuclear power plant, the method proposed in this invention was used to obtain the rod position measurement threshold, and it was applied to the rod position measurement system equipment. The test results show that the rod position measurement accuracy based on this threshold is greatly improved from ±8 steps in the full stroke to ±6 steps, and the rod position threshold debugging time is greatly reduced, which has great application value.

[0065] The present invention is described in detail above with reference to the accompanying drawings and embodiments, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of ordinary technicians in the field without departing from the purpose of the present invention. The contents not described in detail in the present invention can adopt the existing technology.

Claims

1. A reactor rod position measurement threshold intelligent fitting method, characterized in that: The method comprises: Step 1, collecting the original rod position measurement signal of the rod position detector; Step 2: Process the collected original rod position measurement signal to obtain an amplitude waveform of the rod position measurement signal; Step 3, mapping the amplitude waveform of the rod position measurement signal and the given rod position to obtain the amplitude range of the amplitude waveform corresponding to each given rod position; Step 4, weighting the amplitude range of the amplitude waveform corresponding to each given rod position; Step 5: Overlap the amplitude ranges of the amplitude waveforms corresponding to all given rod positions to obtain the amplitude range with the highest weighting coefficient after overlapping, which is the obtained measurement threshold range.

2. The method for intelligent fitting of reactor rod position measurement threshold according to claim 1, characterized in that: In step 1, the rod position detector is composed of a primary coil, an auxiliary coil and multiple groups of measuring coils.

3. The reactor rod position measurement threshold intelligent fitting method according to claim 2, characterized in that: In step 1, the primary coil of the rod position detector receives an AC power supply as its excitation power supply.

4. The method for intelligent fitting of reactor rod position measurement threshold according to claim 2, characterized in that: In step 1, when the control rods in the reactor move in the rod position detector, the induced voltage signals of each group of measuring coils are collected, which are the original rod position measurement signals.

5. The method for intelligent fitting of reactor rod position measurement threshold according to claim 1, characterized in that: The waveform processing in step 2 includes filtering processing and amplitude calculation.

6. The method for intelligent fitting of reactor rod position measurement threshold according to claim 5, characterized in that: The filtering process adopts a low-pass filtering method to filter out frequency interference components other than the AC power supply frequency in the rod position measurement signal.

7. The method for intelligent fitting of reactor rod position measurement threshold according to claim 1, characterized in that: The weighting coefficient used in step 4 is determined by the expected stick position boundary point corresponding to a given stick position. The higher the expected boundary point, the larger the value of the weighting coefficient for the amplitude range corresponding to the given stick position.

8. The method for intelligent fitting of reactor rod position measurement threshold according to claim 1, characterized in that: The weighting coefficients used in the weighting in step 4 are based on the normal distribution probability.

9. The method for intelligent fitting of reactor rod position measurement threshold according to claim 1, characterized in that: When the amplitude ranges of the amplitude waveforms corresponding to all given rod positions are overlapped in step 5, the weighted coefficients of the overlapping parts are added together, and the amplitude with the highest weighted coefficient is the rod position measurement threshold.

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