Automatic test method for availability of rod falling function of control rod and DCS (Distributed Control System)

Abstract

The invention relates to a control rod drop function availability automatic test method and a DCS system, and the method comprises the steps: receiving a test start instruction, entering a test mode, and in the test mode, obtaining the test sequence of each test rod group, and the measurement rod position and the counting rod position of a control rod; sending a bar moving instruction to the current test bar group; after the control rod action of the current test rod group is completed, the counting rod position is consistent with the target rod position, and the change of the measuring rod position of the control rod is detected; judging whether the change of the measurement rod position of the control rod accords with a preset threshold value; and if yes, judging that the control rod drop function availability test of the current test rod group is qualified. According to the invention, the availability test of the rod falling function of the control rod is changed from the traditional manual operation to the automatic test, so that the loss caused by human errors is effectively avoided; time consumed by the whole test is shortened, manpower is saved, and test execution efficiency is improved; and automatic checking is carried out, and a test result is given, so that human errors caused by long manual checking time are avoided.

Description

Technical Field

[0001] The present invention relates to the field of automation, and in particular to an automated test method for availability of a control rod drop function and a DCS system. Background Art

[0002] Nuclear power units need to perform control rod drop function availability tests every month to check that the control rods operate normally and without jamming, and to ensure that the control rods can drop to realize the shutdown function after the shutdown signal appears. According to production management needs, the tests are all scheduled to be performed during the night shift. The operations in the test involve changes in reactivity, and the operator must continue to focus on the operation. The deputy shift supervisor must monitor the entire process, which takes more than 4 hours. There is a risk of human error due to misoperation and the consequences of misoperation are serious. The deputy shift supervisor and the primary circuit operator focus on the test for a long time, which affects the overall monitoring of the unit.

[0003] The complex interface, cumbersome operation and long workload bring psychological and physical pressure to the operator, which is very prone to human error. Due to the long-term focus on the test, the monitoring of other equipment in the unit is reduced. All these are not conducive to the safe and stable operation of the nuclear power plant unit.

[0004] For example, during the test, the control rod will move 3 steps, each step is 1 cm, and the change is generally more than 2 cm. Compared with the range of 416 cm, this change is relatively small. In the process of verifying the test results, the operator needs to retrieve the historical trend and zoom in, measure and calculate with a ruler, and finally give a conclusion on whether the test is qualified (whether the change is greater than the 2 cm standard), which takes a long time and may lead to misjudgment. Summary of the invention

[0005] The technical problem to be solved by the present invention is that operators frequently perform repeated operations, which is prone to human errors, and the verification of test results requires manual verification by the operator, which is time-consuming and prone to errors.

[0006] The technical solution adopted by the present invention to solve the technical problem is: an automated test method for the availability of a control rod drop function, applied to a DCS system, wherein the DCS system is communicatively connected with a rod control system, and the rod control system is used to control the movement of the control rod according to instructions, including:

[0007] S1, receiving a test start instruction, entering a test mode, and in the test mode, obtaining a test sequence of each test rod group, a measuring rod position and a counting rod position of a control rod in the test rod group;

[0008] S2. According to the test sequence, by sending instructions to the rod control system, each test rod group is tested in turn in the following manner:

[0009] S21, sending a rod moving instruction to the current test rod group;

[0010] S22, after the control rod of the current test rod group is moved, detecting the change in the measuring rod position of the control rod;

[0011] S23, determining whether the change in the position of the measuring rod meets a preset threshold;

[0012] S24: If yes, it is determined that the control rod drop function availability test of the current test rod group is qualified.

[0013] Preferably, the S21 includes:

[0014] S211, sending a selection instruction to the rod control system, wherein the selection instruction is used to select a current test rod group participating in the test;

[0015] S212, detecting the measuring rod position and the counting rod position of the control rods in the current test rod group, setting the target rod position, and determining whether the deviation between the counting rod position and the target rod position meets a preset threshold;

[0016] S213: If yes, the setting of the target rod position is correct, and a rod moving instruction of the current test rod group is sent to the rod control system.

[0017] Preferably, after S211, the step further includes:

[0018] S214: Determine whether the selected instruction is effective, and if so, execute S212.

[0019] Preferably, the determining whether the selected instruction is effective comprises: after sending the selected instruction to the stick control system, if a feedback signal sent by the stick control system is received, determining that the selected instruction is effective.

[0020] Preferably, the step S24 includes:

[0021] S25, ending the test of the current test rod group and canceling the selection of the current test rod group;

[0022] S26, determining whether all test rod groups have completed the test, if not, sending a selection instruction to the next test rod group according to the test sequence.

[0023] Preferably, before S1, the step further includes:

[0024] S3, sending a speed setting instruction to the rod control system, so that the rod control system sets the displacement speed of the control rod in the test mode;

[0025] S4. Control the control rods to enter a sub-rod group mode, wherein the sub-rod group mode is a preset arrangement of control rods in a nuclear reactor.

[0026] Preferably, it also includes: continuously monitoring the reactor status to determine whether the preset test permission conditions are met, and if not, outputting an alarm signal and terminating the test.

[0027] Preferably, the monitoring of the reactor status includes: monitoring the linear power density, axial power distribution, radial power distribution, DNBR margin, control rod insertion limit, average temperature limit, load rejection, shutdown, and secondary circuit alarm of the core.

[0028] Preferably, the method further comprises: monitoring the action response time of the control rods of the test rod group after receiving the moving rod instruction, and outputting an alarm if the time exceeds a preset time threshold.

[0029] The present invention also provides a DCS system, comprising a processor and a memory storing a computer program, wherein the processor implements any of the above-mentioned control rod drop function availability automated test methods when executing the computer program.

[0030] The implementation of the technical solution of the present invention has the following beneficial effects: 1. The control rod drop function availability test is transformed from a traditional manual operation to an automated test, which reduces human errors and can effectively avoid various losses caused by manual operation errors; 2. The time spent on the entire test is shortened, a large amount of manpower is saved, and the efficiency of test execution is improved; 3. The test results are automatically given through signal acquisition and automatic calculation, so as to avoid long manual verification time and easy human errors.

[0031] In addition, in order to prevent the possible abnormal logic startup of the automated test, the present invention sets the rod speed setting and the sub-rod group mode outside the test logic, and also sets the abnormal alarm brake logic to promptly remind the operator to intervene manually when an abnormal alarm is generated. The technical solution of the present invention can realize the automation of the entire test process, and the test will be automatically terminated after an abnormality occurs, without the need for manual intervention by the operator. The automated test method can free the operator from tedious operations, and more energy can be spent on the overall control of the test and monitoring in the main control room. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0033] Figure 1 This is a diagram of the operation interface of the control rod drop function availability test system of the present invention;

[0034] Figure 2 1. It is a schematic diagram for checking the test results of the availability of the control rod drop function of the present invention;

[0035] Figure 3 It is a logic block diagram of an embodiment of an automated test method for availability of control rod drop function of the present invention;

[0036] Figure 4 It is a logic block diagram of an embodiment of an automated test method for availability of control rod drop function of the present invention;

[0037] Figure 5 The present invention is a structural diagram of an embodiment of an automated test system for control rod drop function availability. DETAILED DESCRIPTION

[0038] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, the specific implementation of the present invention is now described in detail with reference to the accompanying drawings. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0040] A nuclear power unit in my country needs to perform a control rod drop function availability test every month. Currently, this is done manually by the operator. The operation interface is as follows: Figure 1 As shown. Figure 1 In the figure, the horizontal coordinates A to T and the vertical coordinates 1 to 17 represent the positions of 89 control rods in the reactor core. The 89 control rod groups are grouped as shown in Table 1: the control rods are divided into N01 to N13, PA to PI and the central rod central, see the first column. For example, the first row N01 rod group, which belongs to the N2 shutdown rod, is controlled by the 3-zone RodPilot control cabinet and includes rod 01 in zone 1, rod 26 in zone 2, rod 51 in zone 3 and rod 76 in zone 4. Rod 01 is located at the core R15 coordinate position, rod 26 is located at the core R03 coordinate position, rod 51 is located at the core C03 coordinate position, and rod 76 is located at the core C15 standard position.

[0041]

[0042] Table 1: Control rod grouping table

[0043] The availability test is a control rod drop function availability test that nuclear power units need to perform regularly. The purpose is to check that the control rods operate normally and without jamming, so as to ensure that the control rods can drop to realize the shutdown function after the shutdown signal appears.

[0044] In the prior art, the operator needs to perform the following 46 operations (23 groups of rods, one time for lifting and inserting each) on all 23 sub-rod groups, and check the test results.

[0045] The complex interface, cumbersome operation and long workload bring psychological and physical pressure to the operator, which is very prone to human error. Due to the long-term focus on the test, the monitoring of other equipment in the unit is reduced. All these are not conducive to the safe and stable operation of the nuclear power plant unit.

[0046] For example, during the test, the control rod will move 3 steps, and accordingly, the counting rod position changes 3 steps, and the measuring rod position changes 2 cm or more. Among them, for every 1 step of displacement, the control rod moves 1 cm, and the change of 3 steps totals 2 to 3 cm. Compared with the range of 416 cm, this change is relatively small. Figure 2 As shown, during the verification of the test results, the operator needs to retrieve the historical trend and zoom in, measure and calculate with a ruler, and finally give a conclusion on whether the test is qualified (whether the change is greater than the 2cm standard). This is time-consuming and may lead to misjudgment.

[0047] like Figure 3 As shown, in a first embodiment of a control rod drop function availability automated test method of the present invention, a control rod drop function availability automated test method is provided, which is applied to a DCS system. The DCS system is connected to the existing rod control system of a nuclear power plant in communication, and the rod control system is used to control the movement of control rods according to instructions. The control rod drop function availability automated test method includes the following steps:

[0048] S1. Receive the test start instruction, enter the test mode, and in the test mode, obtain the test sequence of each test rod group, the measuring rod position and the counting rod position of the control rods in the test rod group. In this step, it should be noted that: after the DCS system receives the test start instruction, the test mode is triggered, and the DCS system actively obtains the order of each test rod group participating in the test, the current measuring rod position and the counting rod position of each control rod in the test rod group, so as to generate the target rod position of each control rod in the test process according to the test logic. Among them, the test sequence is the order in which all test rod groups participate in the test. After the DCS system groups all the control rods to be involved, the DCS system automatically generates them according to the preset logic. The measuring rod position refers to the exact position of the control rod in the core directly measured by the physical sensor. The counting rod position refers to the number of control rod action steps. Each control rod action step is counted once, and the accumulated number is called the counting rod position. The test rod group is obtained after all the control rods to be tested are grouped. Each test rod group contains a number of control rods. After the test mode is triggered, all control rods in the same test rod group participate in the test in the same batch.

[0049] In a specific embodiment, the control rod needs to move 6 steps, including 3 steps of inserting the rod and 3 steps of lifting the rod. The control rod moves 1 cm in each step. In this process, the DCS system will perform detection after each control rod moves in place, and comprehensively judge whether the control rod availability test is qualified. The technical solution of this embodiment can be automatically detected and judged by the DCS system to obtain correct test results. Compared with the traditional test, the operator must judge the control rod displacement of 2-3 cm in total in each three steps based on the overall range of 416 cm. The operator needs to call up the historical trend and enlarge it, measure and calculate with a ruler, and finally give a conclusion on whether the test is qualified. The shortcomings of easy misjudgment and long time consumption in the judgment process are overcome. The test results are automatically given through signal acquisition and automatic calculation, freeing the operator's attention from tedious work and paying more attention to the monitoring of the unit status.

[0050] S2. According to the test sequence, by sending instructions to the rod control system, each test rod group is tested in the following manner:

[0051] S21, sending a rod moving instruction to the current test rod group. In this step, it should be noted that the DCS system will send a rod moving instruction to the rod group that currently needs to undergo an availability test according to the pre-set test sequence. The instruction includes the target rod position and displacement speed of the control rod.

[0052] S22, after the control rod movement of the current test rod group is completed, the change in the measuring rod position of the control rod is detected. In this step, it should be noted that the DCS system can monitor the rod position of the control rod and whether displacement occurs, so the DCS system can monitor the movement state of the control rod and the measuring rod position through the change in position before and after displacement.

[0053] S23, judging whether the change in the measuring rod position meets the preset threshold. In this step, it should be noted that the DCS system can collect data from the displacement detector of the control rod, that is, the measuring rod position signal, and judge whether the change in the measuring rod position meets the preset error threshold when the control rod moves in place and the counting rod position is equal to the target rod position.

[0054] S24. If yes, it is determined that the control rod drop function availability test of the current test rod group has passed.

[0055] If not, an alarm signal is output and the test is terminated to remind the staff to intervene. After the staff has completed the processing, they can choose whether to continue the test.

[0056] In an optional embodiment, if not, the control rod is marked as unqualified in the rod drop function availability test, and the control rod is skipped. After the test of all test rod groups is completed, a signal is output to remind the operator to intervene.

[0057] Implementing the technical solution of this embodiment has the following beneficial effects: 1. The control rod drop function availability test is transformed from traditional manual operation to automated test, which reduces human errors and can effectively avoid various losses caused by manual operation errors; 2. The time spent on the entire test is shortened, a lot of manpower is saved, and the efficiency of test execution is improved; 3. The test results are automatically given through signal acquisition and automatic calculation, avoiding long manual verification time and easy human errors.

[0058] like Figure 4 As shown, in another embodiment of a control rod drop function availability automated test method of the present invention, S21 includes:

[0059] S211, sending a selection instruction to the rod control system, the selection instruction is used to select the current test rod group participating in the test. In this step, it should be noted that each test can only carry out the availability test for a limited number of control rods, and the number of control rods in a nuclear power plant is large. Considering the impact of a large number of control rod actions on the core reactivity, it is impossible to put all control rods into the availability test at the same time. Therefore, after the control rods are grouped, it is necessary to issue control instructions in sequence in groups. When a test rod group is conducting the test, the other rod groups are in a waiting state. Therefore, it is necessary to send a selection instruction to the current test rod group participating in the test, and the unselected test rod group is in a waiting state.

[0060] In an optional embodiment, after S211, it also includes: S214, judging whether the selected instruction is effective, and if so, executing S212. In this step, it should be noted that the DCS system needs to judge whether the selected instruction is effective through the feedback signal. If it is not effective, an alarm signal is output, and the test is terminated at the same time to remind the staff to intervene. After the staff has completed the processing, the staff chooses whether to continue the test. Avoid the situation where the selected instruction is not effective, resulting in the test rod group failing to receive the rod moving instruction sent by the DCS system through the rod control system, and then resulting in the failure to move the rod, but the system still judges whether the availability is qualified based on the normal progress of the test. The implementation of the technical solution of this embodiment can supplement the logical loopholes of the DCS system in the availability test of the control rod drop function, ensure that the operation of the control rod is carried out as expected, and avoid potential risks caused by the failure to execute the instruction.

[0061] In an optional embodiment, determining whether the selected instruction is effective includes: after sending the selected instruction to the stick control system, if a feedback signal sent by the stick control system is received, then determining that the selected instruction is effective. In this embodiment, the system confirms whether the selected instruction is effective by receiving a signal fed back by the stick control system. The presence of the feedback signal provides an additional checking mechanism, which helps to detect and prevent possible system failures or errors, thereby improving the reliability of the entire stick control system, and can reduce the need for operators to continuously monitor the system, because they can automatically confirm the success of the operation, thereby optimizing the operation process and improving efficiency.

[0062] S212, detecting the measuring rod position and counting rod position of the control rods in the current test rod group, setting the target rod position, and judging whether the deviation between the counting rod position and the target rod position meets the preset threshold. In this step, it should be noted that the setting of the target rod position needs to be in accordance with the preset test logic, and has a certain deviation from the counting rod position, otherwise, the setting of the target rod position is unreasonable. In some embodiments, the target rod position is set to the counting rod position plus three or the counting rod position minus three, and after the control rod is inserted three steps or lifted three steps, the counting rod position is consistent with the target rod position.

[0063] S213: If yes, the target rod position is set correctly, and a rod moving instruction for the current test rod group is sent to the rod control system.

[0064] By implementing the technical solution of this embodiment, the selected state and the target stick position setting can be confirmed in advance, which can ensure that the execution of the stick moving instruction is consistent with the operator's intention. Figure 1 It can reduce the unexpected risks caused by misoperation or setting errors and help prevent power outages or safety accidents caused by improper control rod position.

[0065] In a specific embodiment, S24 includes:

[0066] S25, end the test of the current test rod group, and deselect the current test rod group. In this step, it should be noted that after the test of the control rod group is completed, the DCS system stops all operations on the control rod group, deselects it from the test state, removes the highlight or mark of the rod group to indicate that it is no longer in the active test state, stops further movement of the control rods, records the current position and test data, and ensures that the control rods are in a safe position.

[0067] S26. Determine whether all test rod groups have completed the test. If not, send a selection instruction to the next test rod group according to the test sequence. In this step, it should be noted that after completing the test of the current test rod group, it is necessary to check whether all test rod groups have completed their tests. This process can be determined by checking the test progress and status records. After each test rod group completes the test, the DCS system will mark it as a completed test state when unselecting the test rod group, and record it and generate a test record for the DCS system and operators to query. If all test rod groups have completed the test, the entire test process is over, and the test mode is automatically exited. If there are still unfinished test rod groups, the control system needs to select the next test rod group to be tested according to the predetermined test sequence.

[0068] Implementing the technical solution of this embodiment can ensure that all test rod groups complete the control rod drop function availability test, which helps to ensure the safety and reliability of the reactor. By systematically testing each test rod group, operators can verify the function of the control rod drive mechanism and ensure that they can accurately and reliably perform their functions when needed.

[0069] In a specific embodiment, before S1, the method further includes:

[0070] S3. Send a speed setting instruction to the rod control system so that the rod control system sets the displacement speed of the control rod in the test mode. In this step, it should be noted that before the availability test of the control rod is performed, the movement speed of the control rod in the test mode needs to be set first to generate the rod movement instruction. This speed setting is to ensure that the control rod moves smoothly and controllably and meets the test requirements.

[0071] S4. Control the control rods to enter the rod group mode, where the rod group mode is a preset arrangement of control rods in a nuclear reactor. In this step, it should be noted that the rod group mode is a specific control mode, in which the control rods are controlled in the form of a test rod group, and the control rods in each rod group can move independently or collaboratively to achieve precise control of reactor power and reactivity. This mode allows more detailed and flexible adjustments to adapt to different operating conditions and control requirements.

[0072] The implementation of the technical solution of this embodiment can ensure the precise control of the control rods during the test, which helps to evaluate and verify the responsiveness and reliability of the control rod system. It ensures that the test is carried out under safe and controlled conditions, and at the same time collects valuable data to optimize the operation and control of the reactor. It should be noted that in order to avoid abnormal startup of the test logic, the rod speed setting, the control rod manual control mode and the control rod sub-rod group mode are not included in the test logic.

[0073] In a specific embodiment, it also includes: continuously monitoring the reactor status to determine whether the preset test permission conditions are met. If not, an alarm signal is output and the test is terminated. Among them, monitoring the reactor status includes but is not limited to: monitoring the linear power density, axial power distribution, radial power distribution, DNBR margin, control rod insertion limit, average temperature limit, load rejection, shutdown, and secondary circuit alarm of the core. If the DCS system detects any alarm signal that affects the test, the test is terminated immediately and the staff is reminded to intervene. After the staff eliminates the alarm signal that interferes with the test, the operator chooses whether to continue the test.

[0074] In this embodiment, during the test, the DCS system will also monitor some key signals in the reactor, such as line power density alarm, thermal power alarm, control rod failure, etc. When abnormal signals are found, the brake logic will automatically start, and the test can be suspended to give operators and maintenance personnel time to intervene. The test can be continued after the abnormality is handled. The automated brake logic reduces the risk of delayed response or wrong decision-making by the operator in an emergency, and improves the reliability and stability of the entire DCS system.

[0075] In a specific embodiment, the DCS system also monitors the action response time of the control rods of the test rod group after receiving the moving rod instruction. If it exceeds the preset time threshold, an alarm is output. In this embodiment, the action response time refers to the time required for the control rod to move from a stationary state to a specified position after receiving the moving instruction. This time includes the time for the system to process the instruction, the start-up time of the mechanical components, the acceleration time, and the deceleration and stop time. By implementing the technical solution of this embodiment, by monitoring the action response time of the control rod, it can be ensured that the control rod reaches the specified position within the predetermined time. If the response time is too long, an alarm signal can be output so that the operator can make timely adjustments and interventions, thereby enhancing the safety of the test process.

[0076] like Figure 5 As shown, the present invention also constructs a DCS system, including a processor and a memory storing a computer program, and the processor implements the control rod drop function availability automated test method disclosed in any of the above embodiments when executing the computer program.

[0077] Furthermore, the DCS system receives the operator's instructions through its own operation interface and transmits them to the rod control system through the gateway. The gateway has multiple Ethernet ports and supports multiple industrial communication protocols. It is responsible for protocol conversion and data routing to ensure accurate data transmission between the DCS system and the rod control system. The rod control system feeds back the status information of the control rods to the DCS system, and the DCS system displays this information on the operator interface. The control rod control system is controlled by the control rod drop function availability automation test method disclosed in any of the above embodiments, so as to perform availability test on the control rods.

[0078] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, software modules executed by a processor, or a combination of the two. The DCS system may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0079] It is understood that the above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, the above technical features can be freely combined without departing from the concept of the present invention, and several deformations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, all equivalent changes and modifications made to the scope of the claims of the present invention should belong to the coverage of the claims of the present invention.

Claims

1. An automated test method for the availability of control rod drop function, applied to DCS system, wherein: The DCS system is in communication with a rod control system, and the rod control system is used to control the movement of the control rod according to the instructions, and is characterized by comprising: S1, receiving a test start instruction, entering a test mode, and in the test mode, obtaining a test sequence of each test rod group, a measuring rod position and a counting rod position of a control rod in the test rod group; S2. According to the test sequence, by sending instructions to the rod control system, each test rod group is tested in turn in the following manner: S21, sending a rod moving instruction to the current test rod group; S22, after the control rod of the current test rod group is moved, detecting the change in the measuring rod position of the control rod; S23, determining whether the change in the position of the measuring rod meets a preset threshold; S24: If yes, it is determined that the control rod drop function availability test of the current test rod group is qualified.

2. The control rod drop function availability automated test method according to claim 1, characterized in that: The S21 includes: S211, sending a selection instruction to the rod control system, wherein the selection instruction is used to select a current test rod group participating in the test; S212, detecting the measuring rod position and the counting rod position of the control rods in the current test rod group, setting the target rod position, and determining whether the deviation between the counting rod position and the target rod position meets a preset threshold; S213: If yes, the setting of the target rod position is correct, and a rod moving instruction of the current test rod group is sent to the rod control system.

3. The control rod drop function availability automated test method according to claim 2, characterized in that: The S211 also includes: S214: Determine whether the selected instruction is effective, and if so, execute S212.

4. The control rod drop function availability automated test method according to claim 3, characterized in that: The determining whether the selected instruction is effective comprises: after sending the selected instruction to the stick control system, if a feedback signal sent by the stick control system is received, determining that the selected instruction is effective.

5. The control rod drop function availability automated test method according to claim 2, characterized in that: The S24 then includes: S25, ending the test of the current test rod group and canceling the selection of the current test rod group; S26, determining whether all test rod groups have completed the test, if not, sending a selection instruction to the next test rod group according to the test sequence.

6. The control rod drop function availability automated test method according to claim 1, characterized in that: The S1 also includes: S3, sending a speed setting instruction to the rod control system, so that the rod control system sets the displacement speed of the control rod in the test mode; S4. Control the control rods to enter a sub-rod group mode, wherein the sub-rod group mode is a preset arrangement of control rods in a nuclear reactor.

7. The control rod drop function availability automated test method according to claim 1, characterized in that: Also includes: The reactor status is continuously monitored to determine whether the preset test permission conditions are met. If not, an alarm signal is output and the test is terminated.

8. The control rod drop function availability automated test method according to claim 7, characterized in that: The monitoring of the reactor status includes: monitoring the linear power density of the core, axial power distribution, radial power distribution, DNBR margin, control rod insertion limit, average temperature limit, load rejection, shutdown, and secondary circuit alarm.

9. The control rod drop function availability automated test method according to claim 1, characterized in that: Also includes: The action response time of the control rods of the test rod group after receiving the moving rod instruction is monitored, and if it exceeds a preset time threshold, an alarm is output.

10. A DCS system, comprising a processor and a memory storing a computer program, characterized in that: When executing the computer program, the processor implements the control rod drop function availability automated testing method as described in any one of claims 1 to 9.

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