Method and device for automatically verifying a nuclear reactor control rod position measurement signal channel

Abstract

The present application relates to the field of reactor control, especially to a nuclear reactor control rod position measurement signal channel automatic verification method and device. The automatic verification method is: through the reserved interface of the field coding module to realize signal injection, through the network communication party to collect the measured rod position after the decoding of the physical range; through the automatic verification software in the upper computer to compare whether the actual measured rod position is same with the expected measured rod position corresponding to the signal injection, to judge whether the signal transmission channel is normal. The present application sets two modes: manual input verification and one-key complete verification, respectively realizes the accurate verification for specific rod position and the rapid verification of the full rod position traversal in the given sequence, can automatically determine the verification result, avoids human error, improves work efficiency and reduces labor cost.

Description

Technical Field

[0001] This invention relates to the field of reactor control, and more particularly to an automatic verification method and apparatus for nuclear reactor control rod position measurement signal channels. Background Technology

[0002] Nuclear reactors commonly use control rods as neutron absorbers to control the neutron flux level in the reactor core. Control rod position detectors, as a special type of instrument, use the principle of electromagnetic induction to generate an induced voltage in a measuring coil, thus detecting the height of the control rod within the reactor core.

[0003] The rod position detection coil mainly includes one primary coil covering the entire stroke, two auxiliary coils located at the upper and lower ends respectively, and five groups of 32 secondary coils (the coils are arranged at intervals of eight mechanical steps).

[0004] The primary coil is excited by alternating current, generating an alternating magnetic field. The auxiliary coil acts as negative feedback for regulating the primary coil current, stabilizing the primary coil current and providing a stable magnetic field for the coupling of the secondary coil, so that the induced voltage of the secondary coil depends only on the coupling of the drive rod.

[0005] The secondary coil generates an induced voltage in the alternating magnetic field, but the voltage amplitude is close to zero. When the driving rod, made of magnetic material, passes through, the induced voltage of the secondary coil increases sharply (reaching the volt level). Five sets of secondary coils are connected in series in opposite directions within the same set. The induced voltages cancel each other out due to their opposite polarity. The amplitude of the voltage at the induction terminal of each set of coils depends only on the position of the top of the driving rod. The voltage at the secondary coil terminals is processed by the rod position encoding module and converted into a measurement rod position; therefore, the secondary coil is also called the "measuring coil."

[0006] The primary coil of the rod position detector is powered by the power supply module, and the auxiliary coil provides negative feedback to reduce the influence of temperature or electromagnetic interference on the induced voltage of the measuring coil.

[0007] The induced voltage of the measuring coil is sent to the processing and encoding module, where it is rectified, filtered, and threshold compared to generate high and low level signals, i.e. Gray code signals, which are then sent to the rod position processing cabinet.

[0008] The measuring coils are divided into five groups: A, B, C, D, and E. Adjacent coils within a group are connected in reverse series. Only one measuring coil is deployed every eight machine steps, so that there is exactly one different bit in any adjacent codes, which is distributed in a "Gray code" pattern, resulting in the lowest transmission error rate.

[0009] The induced voltage at both ends of the coil is filtered, rectified, and threshold compared by the encoding module to form a set of signals characterized by on / off states. These signals are acquired by the input module as binary signals and then decoded by software to convert them into the position of the control rod with a physical range, which is used for personnel monitoring and alarm logic.

[0010] As usage time increases, detectors, encoding modules, input modules, software, connectors, and cables on the bar measurement channel may all malfunction. The current verification method involves manually injecting signals and checking for expected performance. With the increase in the number of measurement coils, the number of signal combinations grows exponentially; consequently, the number of channel verifications increases exponentially with the increase in the number of detectors, making manual verification time-consuming. Furthermore, since the binary signals of two adjacent measurement bars differ by only one bit, there is a high probability of human error. Summary of the Invention

[0011] The technical problem to be solved by the present invention is to provide an automatic verification method and device for the position measurement signal channel of nuclear reactor control rods, which can automatically determine the verification result, avoid human error, improve work efficiency, and reduce labor costs.

[0012] This invention provides an automatic verification method for nuclear reactor control rod position measurement signal channels, comprising the following steps:

[0013] The device using this automatic verification method injects signals through the reserved interface of the field coding module and acquires the position of the measuring rod that has been decoded into the physical range through network communication.

[0014] The automatic verification software in the host computer compares the actual measurement rod position with the expected measurement rod position corresponding to the signal injection to determine whether the signal transmission channel is normal, and displays and saves the verification results.

[0015] Preferably, the host computer provides a manual input verification mode, specifically:

[0016] Manually input the physical range bar position or binary Gray code to verify whether it is the same as the expected measurement bar position corresponding to the signal injection, and display it in the display unit in two forms.

[0017] Preferably, during the manual input verification, another position can be switched at any time.

[0018] Preferably, the host computer provides an automatic verification mode, specifically:

[0019] Rapid verification of multiple channels simultaneously traversing all positions in a predetermined order.

[0020] Preferably, a time interval for switching between adjacent rod positions is set before verification, and during verification, the continuous changes of the rod position from low to high and from high to low are observed.

[0021] This invention provides an automatic verification device for the control rod position measurement signal channel of a nuclear reactor. It is connected to the encoding module through the signal injection interface of the encoding module and to the rod position measurement system through the acquisition interface.

[0022] Preferably, the automatic verification device includes:

[0023] The base plate is equipped with a PLC power supply module, a PLC controller module, a PLC communication module, and a PLC digital output module.

[0024] The PLC power module supplies power to the PLC controller module, PLC communication module, and PLC digital output module via the base plate.

[0025] The PLC controller module is connected and communicates with the host computer via a network cable, enabling the download of software configuration from the host computer to the PLC and the upload of real-time test data from the PLC to the host computer.

[0026] The PLC communication module and the rod control system are connected and communicated via network cable to realize the acquisition and input of the rod position in the field.

[0027] The PLC digital output module uses a pre-installed PLC cable to connect to the terminal block, which is then converted into a hard-wired connection that passes through the flange of the verification device housing and connects to the bar coding module via a connector that matches the reserved interface.

[0028] Preferably, the PLC power supply module is a 24V power supply module, which is directly supplied by an AC-DC conversion power supply module;

[0029] The battery and the AC / DC conversion power supply module together form an uninterruptible power supply unit.

[0030] Preferably, the PLC of the automatic verification device and the rod position measurement system use the same model of PLC.

[0031] Compared with the prior art, the automatic verification method and apparatus for nuclear reactor control rod position measurement signal channels of the present invention have the following advantages:

[0032] (1) Without modifying the existing equipment and interfaces, the automatic verification of the control rod position measurement signal channel is achieved by replacing manual labor with software, thereby improving work efficiency;

[0033] (2) Since the measuring rod position follows the Gray code encoding rule, there is only one bit difference between two adjacent signals. Software is used to avoid human error caused by manual dialing.

[0034] (3) By replacing the signal injection and rod position acquisition equipment, the software does not need to be changed or adaptively fine-tuned, and can be compatible with various control rod position measurement systems, and has a certain expansion capability. Attached Figure Description

[0035] Figure 1 This is a flowchart illustrating the automatic verification process for the control rod position measurement signal channel.

[0036] Figure 2This is a schematic diagram of an automatic verification device.

[0037] In the picture,

[0038] 1 is the rod position detector; 2 is the rod position encoding module; 3 is the rod position Gray code acquisition module; 4 is the decoding module; 5 is the rod position measurement; 6 is the automatic verification device; 7 is the signal injection interface of the encoding module; 8 is the rod position acquisition interface; 9 is the PLC power supply module; 10 is the PLC controller module; 11 is the PLC communication module; 12 is the PLC digital output module; 13 is the base plate; 14 is the AC / DC conversion power supply module; 15 is the battery; 16 is the terminal block; 17 is the host computer. Detailed Implementation

[0039] To further understand the present invention, embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the present invention.

[0040] An embodiment of the present invention discloses an automatic verification method for the position measurement signal channel of a nuclear reactor control rod, comprising the following steps:

[0041] The device using this automatic verification method injects signals through the reserved interface of the field coding module and acquires the position of the measuring rod that has been decoded into the physical range through network communication.

[0042] The automatic verification software on the host computer compares the actual measurement rod position with the expected measurement rod position corresponding to the signal injection to determine whether the signal transmission channel is normal, and displays and saves the verification results.

[0043] There are two verification modes: manual input verification and one-click full verification.

[0044] The host computer provides a manual input verification mode, specifically:

[0045] Manually input the physical range bar position or binary Gray code to verify whether it is the same as the expected measurement bar position corresponding to the signal injection, and display it in the display unit in two forms.

[0046] The manual input mode is designed for verifying specific probe positions. It is primarily suitable for accurately troubleshooting channels and probe positions suspected of having faults, providing stable input over a long period to facilitate fault location. It can be switched to another probe position at any time for easy comparison and judgment. Depending on the needs, the physical range probe position or binary Gray code can be selected for input. The display unit shows both formats for easy comparison.

[0047] The host computer provides an automatic verification mode, specifically:

[0048] Rapid verification of multiple channels simultaneously traversing all positions in a predetermined order.

[0049] The automatic verification mode is suitable for preventative inspections, enabling rapid verification of all test positions simultaneously across multiple channels in a predetermined order. The time interval between switching between adjacent test positions can be manually set, allowing for observation of the continuous changes in test positions from low to high and from high to low via an engineer's workstation.

[0050] The hardware is based on a programmable logic controller (PLC) and includes a processor module, baseboard, power supply module, output module, communication module, communication cable, host computer, and other hardware such as connectors and cables for connecting to the reserved interface of the encoding module, power supply unit, power cables, uninterruptible power supply unit composed of batteries, printer, etc.

[0051] The output voltage level is determined by actual needs and is equipped with a voltage regulating device; the communication module is adapted to actual application scenarios and can collect data from the field rod control system or DCS.

[0052] This invention discloses an automatic verification device for the control rod position measurement signal channel of a nuclear reactor, comprising: a rod position detector 1, a rod position encoding module 2, a rod position Gray code acquisition module 3, a decoding module 4, and a rod position measurement system 5 connected in sequence; the automatic verification device 6 is connected to the encoding module 2 through the encoding module signal injection interface 7 and to the rod position measurement system 5 through the acquisition interface 8. By replacing the signal injection and rod position acquisition devices, the software does not need to be changed or adaptively fine-tuned, and it can achieve compatibility with various control rod position measurement systems.

[0053] Figure 1 In the process, the measurement rod position is input to the automatic verification device through the measurement rod position acquisition interface; the simulated rod position signal is output to the encoding module through the signal injection interface.

[0054] Automated verification devices are further refined into Figure 2 .

[0055] Figure 2 In the middle, the base plate 13 is equipped with a PLC power supply module 9, a PLC controller module 10, a PLC communication module 11, and a PLC digital output module 12.

[0056] PLC power module 9 supplies power to PLC controller module 10, PLC communication module 11 and PLC digital output module 12 through base plate 13;

[0057] The PLC controller module 10 is connected and communicates with the host computer 17 via a network cable, enabling the download of software configuration from the host computer 17 to the PLC and the upload of real-time test data from the PLC to the host computer 17.

[0058] The PLC communication module 11 is connected and communicates with the rod position measurement system or DCS via a network cable to realize the acquisition and input of the rod position measurement on site;

[0059] The PLC of the automatic verification device and the rod position measurement system use the same model of PLC, so there is no communication compatibility problem and communication is easy to achieve.

[0060] The PLC digital output module 12 is connected to the terminal block 16 using a pre-installed PLC cable, which is then converted to a hard-wired connection passing through the flange of the verification device housing. It is then connected to the bar encoder module 2 via a connector that matches the reserved interface. A voltage amplitude adjustment circuit is configured to match the output voltage to the voltage level required by the encoder module.

[0061] The PLC power supply module is a 24V power supply module, which is directly supplied by the AC-DC conversion power supply module 14.

[0062] The AC-DC conversion power supply module 14 converts the factory's 220V AC power to 24V DC power, and is equipped with an uninterruptible power supply unit consisting of a battery 15.

[0063] In the host computer, automatic verification software for the control rod position measurement signal channel is developed based on PLC configuration software.

[0064] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0065] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An automatic verification method for nuclear reactor control rod position measurement signal channels, characterized in that, Includes the following steps: The device using this automatic verification method injects signals through the reserved interface of the field coding module and acquires the position of the measuring rod that has been decoded into the physical range through network communication. The automatic verification software in the host computer compares the actual measurement rod position with the expected measurement rod position corresponding to the signal injection to determine whether the signal transmission channel is normal, and displays and saves the verification results. The host computer provides a manual input verification mode, specifically: Manually input the physical range bar position or binary Gray code, verify whether it is the same as the expected measurement bar position corresponding to the signal injection, and display it in two forms in the display unit; The host computer provides an automatic verification mode, specifically: Before verification, set the time interval between switching between adjacent rod positions. During verification, observe the continuous changes of the rod positions from low to high and from high to low. Perform rapid verification by simultaneously traversing all rod positions in a predetermined order across multiple channels. The automatic verification device is connected to the encoding module via the signal injection interface of the encoding module and to the rod position measurement system via the acquisition interface. The automatic verification device includes: The base plate is equipped with a PLC power supply module, a PLC controller module, a PLC communication module, and a PLC digital output module. The PLC power module supplies power to the PLC controller module, PLC communication module, and PLC digital output module via the base plate. The PLC controller module is connected and communicates with the host computer via a network cable, enabling the download of software configuration from the host computer to the PLC and the upload of real-time test data from the PLC to the host computer. The PLC communication module and the rod control system are connected and communicated via network cable to realize the acquisition and input of the rod position in the field. The PLC digital output module uses a pre-installed PLC cable to connect to the terminal block, which is then converted into a hard-wired connection that passes through the flange of the verification device housing and connects to the bar coding module via a connector that matches the reserved interface.

2. The automatic verification method for nuclear reactor control rod position measurement signal channels according to claim 1, characterized in that, During manual input verification, the other position can be switched at any time.

3. The automatic verification method for nuclear reactor control rod position measurement signal channels according to claim 1, characterized in that, The PLC power supply module is a 24V power supply module, which is directly supplied by the AC-DC conversion power supply module. The battery and the AC / DC conversion power supply module together form an uninterruptible power supply unit.

4. The automatic verification method for nuclear reactor control rod position measurement signal channels according to claim 1, characterized in that, The PLC of the automatic verification device and the rod position measurement system use the same model of PLC.

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