Nuclear power plant auxiliary power source switching test method, device and equipment

Abstract

The application provides a nuclear power plant auxiliary power switching test method, device and equipment, and the method comprises the following steps: configuring a BAS56 test and a BAS54 test initial state in parallel, wherein, when the BAS54 test initial state is configured, the available state of a primary loop heat shutdown condition and a condenser vacuum condition auxiliary equipment is maintained, and the auxiliary equipment starting requirement of the auxiliary power supply in the auxiliary variable power supply mode is met; the BAS56 test is executed, and a BAS56 test final state is obtained after the BAS56 test is finished; under the BAS56 test final state, a fast power reversal technology of imitative automatic switching is adopted, and fast power-on and power-off between adjacent nuclear power units of the auxiliary public load of the nuclear power unit is realized; and the BAS56 test final state is taken as the BAS54 test initial state, and the BAS54 test is executed. The application realizes deep decoupling of the auxiliary power switching test and the network-related test, reduces the correlation degree of the auxiliary power switching test on the network-related work, realizes high flexibility of the test window, and further improves the test efficiency, simplifies the test operation and reduces the test risk.

Description

Technical Field

[0001] This invention relates to the field of nuclear power, and more specifically, to a method, apparatus, and equipment for switching power supplies in nuclear power plants. Background Technology

[0002] When a nuclear power plant loses its normal external power supply, the reactor coolant pumps need to be started via auxiliary transformer power supply to restore the primary loop forced circulation and core heat removal capabilities. To this end, the nuclear power plant has implemented a reactor coolant pump start-up test via auxiliary step-down transformer (hereinafter referred to as BAS54) to verify the auxiliary transformer's ability to maintain the primary loop hot shutdown condition and condenser vacuum conditions. This test involves starting auxiliary equipment such as RCP001PO, CRF001PO, CEX001PO, SEN, SRI, CVI, CET, GGR, and GHE via auxiliary transformer power supply while the reactor is in a hot shutdown condition, maintaining the primary loop hot shutdown condition and condenser vacuum conditions.

[0003] To avoid excessively low primary circuit temperatures due to prolonged loss of reactor coolant pumps caused by excessively long station power switching test cycles during the hot functional testing phase, existing technical solutions divide the BAS56 and BAS54 station power switching tests into two separate tests during the hot functional testing phase. Specifically, after the BAS56 test, the three main coolant pumps need to be restarted to heat the primary circuit working fluid, allowing the reactor to return to standard hot shutdown conditions before the BAS54 test is performed. In summary, by using a phased testing approach, the cycle of each individual test is shortened, ultimately achieving control over the primary circuit temperature. Existing station power switching technologies include... Figure 1 As shown.

[0004] The existing technical solution, BAS54 test, involves disconnecting the 500kV ultra-high voltage power supply switch during reactor hot shutdown, triggering automatic switching of the auxiliary transformers. The plant power supply then starts equipment such as RCP001PO, CRF001PO, CEX001PO, SEN, SRI, CVI, CET, GGR, and GHE in auxiliary transformer power supply mode. This test involves the operation of numerous grid-connected devices, thus requiring strict control over the test window and placing high demands on the accuracy and effectiveness of the test operations. Due to the complexity of the test operation and the increased risk, a significant amount of manpower is required. The power supply distribution of auxiliary loads maintaining primary circuit hot shutdown and condenser vacuum conditions in a nuclear power plant is as follows: Figure 2 As shown.

[0005] The existing methods for testing plant power supply switching during the hot functional testing phase have the following shortcomings:

[0006] 1) The test operation window lacks flexibility and continuity. The test methods involve the operation of power grid equipment and are constrained by power grid operation, resulting in poor flexibility in the test execution window. Furthermore, the poor continuous operation conditions of the test methods hinder the control of the main project schedule for hot functional testing.

[0007] 2) Increased costs for plant power consumption, demineralized water production, and process wastewater treatment during commissioning;

[0008] 3) Increased fuel consumption of diesel generators: Before the BAS56 and BAS54 tests are coupled, both tests require the start of two 6000kW emergency diesel generators, which increases the fuel consumption of the emergency diesel generators.

[0009] 4) Increase the number of impact tests on electrical and process equipment, thereby increasing the wear and tear on industrial equipment;

[0010] 5) Increased the number of impacts when large pumps such as main pumps and circulating water pumps lose their auxiliary systems during transient power switching at the plant;

[0011] 6) Increased risk of human error. The restoration of external power supply, plant power distribution system and plant loads, and the restart of the unit involve a large number of systems that need to be restored, which poses a risk of human error.

[0012] 7) Increased labor costs. The restart of the unit involves more than 50 processes, electrical systems and instrumentation systems that need to be restored. Considering that each system requires at least 2 people, the test coupling can save 200 man-days of labor costs. Summary of the Invention

[0013] In view of this, the purpose of the present invention is to provide a method, apparatus and equipment for switching power supply in nuclear power plants, so as to improve the above-mentioned problems.

[0014] The present invention adopts the following solution:

[0015] A method for switching power supplies at a nuclear power plant, comprising:

[0016] The initial states of BAS56 and BAS54 tests are configured in parallel. When configuring the initial state of BAS54 test, the availability of auxiliary equipment under primary circuit hot shutdown and condenser vacuum conditions is maintained to meet the startup requirements of auxiliary equipment in auxiliary transformer power supply mode.

[0017] Perform the BAS56 test and obtain the final state of the BAS56 test after the test is completed;

[0018] Under the final state of the BAS56 test, a fast power-off technology with simulated automatic switching is adopted to achieve rapid power outage and restoration between adjacent units of the nuclear power plant's common load.

[0019] The final state of the BAS56 test was used as the initial state of the BAS54 test, and the BAS54 test was performed.

[0020] Preferably, the steps for performing the BAS56 test are as follows:

[0021] Disconnect the 500kV ultra-high voltage switch from the normal power supply outside the plant;

[0022] The GPA protection action is activated, automatically switching the plant power supply to the auxiliary transformer power supply;

[0023] Restore the 500kV ultra-high voltage switch to normal power supply outside the plant, restore the main transformer to operation, and reset the GPA protection.

[0024] Complete the BAS56 test.

[0025] Preferably, for the unit's common switchboard 7LGI, a rapid power-off technology with simulated automatic switching is adopted to achieve rapid power outage and restoration between adjacent units of the nuclear power unit's common load, specifically including:

[0026] It has been confirmed that the downstream medium-voltage rotating loads supplied by 7LGI have been shut down;

[0027] The test position opening and closing operation of 7LGIB001JA was verified using a test kit.

[0028] Set 7LGIB001JA to the working position, ready for power-off operation;

[0029] Disconnect 7LGIA001JA, confirm that 7LGI is de-energized, and after a predetermined time, close 7LGIB001JA locally. 7LGI will then switch power to the adjacent unit's LGC for operation. If 7LGIB001JA fails to close and the switch to the adjacent unit's LGC for power supply fails, then the 7LGIA001JA switch has been disconnected and placed in the isolation position. Disconnect the DC power supply of the 7LGIA001JA switch and execute the operation of 7LGI being powered by 7LGIB.

[0030] Restore the downstream medium-voltage rotating load powered by 7LGI.

[0031] Preferably, the steps for performing the BAS54 test include:

[0032] Operate the LGA / D to switch to auxiliary transformer power supply operation, and start the primary circuit equipment and secondary circuit equipment in sequence;

[0033] Switch the plant's auxiliary power supply back to the plant transformer, restore the plant's auxiliary equipment, and restore the unit to the thermal power plant shutdown state;

[0034] Complete the BAS54 test.

[0035] Preferably, it further includes:

[0036] When the primary circuit temperature drops to the warning value, the RCP001PO is activated via the auxiliary transformer to maintain the primary circuit temperature.

[0037] If this is not feasible, restore the GEV to supply power to the medium-voltage power distribution system so that operators can start one or more main pumps via the main power supply to maintain the temperature and pressure of the primary circuit.

[0038] Preferably, it further includes:

[0039] In the initial test state, the LHP and LHQ emergency diesel generators are in hot standby mode to ensure that when the plant power supply fails to switch to the auxiliary transformer, the LHP / LHQ emergency generators will automatically start and supply power to the main pump shaft seal and related equipment.

[0040] Preferably, when the LGB fails to switch to the auxiliary transformer, the unit status is managed according to the following contingency plan:

[0041] The inspection confirmed that the LHA is powered by the emergency diesel generator LHP.

[0042] Check and confirm that RCV / RRI / SEC continues to operate;

[0043] Perform RCV and ASG regulation operations to stabilize the primary loop temperature and pressure;

[0044] LGB is now powered by the auxiliary transformer.

[0045] Restore GEW / GEV power supply;

[0046] The plant's power supply was restored to normal operation.

[0047] The test was re-executed with the test conditions reconfigured according to the initial state.

[0048] Preferably, when the switching from LGC to the auxiliary transformer fails, the unit status is controlled according to the following contingency plan:

[0049] The inspection confirmed that LHB is powered by the emergency diesel generator LHQ.

[0050] Check and confirm that RCV / RRI / SEC continues to operate;

[0051] Perform RCV and ASG regulation operations to stabilize the primary loop temperature and pressure;

[0052] Restore power supply to LGC from the auxiliary transformer;

[0053] Restore GEW / GEV power supply;

[0054] The plant's power supply was restored to normal operation.

[0055] The test was re-executed with the test conditions reconfigured according to the initial state.

[0056] Preferably, when both LGB / LGC and auxiliary transformer switching fail, the unit status is managed according to the following contingency plan:

[0057] The inspection confirmed that the LHA is powered by the emergency diesel generator LHP.

[0058] The inspection confirmed that LHB is powered by the emergency diesel generator LHQ.

[0059] Check and confirm that RCV / RRI / SEC continues to operate;

[0060] Perform RCV and ASG regulation operations to stabilize the primary loop temperature and pressure;

[0061] LGB is now powered by the auxiliary transformer.

[0062] Restore power supply to LGC from the auxiliary transformer;

[0063] Restore GEW / GEV power supply;

[0064] The plant's power supply was restored to normal operation.

[0065] The test conditions were reconfigured according to the initial state, and the test was re-executed.

[0066] Preferably, when the LHA to LHP switch fails, the unit status is managed and controlled according to the following contingency plan:

[0067] The inspection confirmed that LHB is powered by the emergency diesel generator LHQ.

[0068] Check and confirm that RCV / RRI / SEC continues to operate;

[0069] Perform RCV and ASG regulation operations to stabilize the primary loop temperature and pressure;

[0070] LGB is now powered by the auxiliary transformer.

[0071] Restore GEW / GEV power supply;

[0072] The plant's power supply was restored to normal operation.

[0073] The test was re-executed with the test conditions reconfigured according to the initial state.

[0074] Preferably, when the switch from LHB to LHQ fails, the unit status is managed according to the following contingency plan:

[0075] The inspection confirmed that the LHA is powered by the emergency diesel generator LHP.

[0076] Check and confirm that RCV / RRI / SEC continues to operate;

[0077] Perform RCV and ASG regulation operations to stabilize the primary loop temperature and pressure;

[0078] Restore power supply to LGC from the auxiliary transformer;

[0079] Restore GEW / GEV power supply;

[0080] The plant's power supply was restored to normal operation.

[0081] The test conditions were reconfigured according to the initial state, and the test was re-executed.

[0082] Preferably, when the switch from LHA / LHB to LHP / LHQ fails, the unit enters SBO mode and the unit status is managed according to the following plan:

[0083] Before the test, RRI / SEC was configured to run in two columns, and the inter-column backup function was enabled.

[0084] Record the status of the RCV equipment before the test;

[0085] Restore power supply from LGB / LHA to the auxiliary transformer or restore power supply from LGC / LHB to the auxiliary transformer;

[0086] Check to confirm that RCV / RRI / SEC is still running; otherwise, start it manually.

[0087] Check the seal injection flow rate of the RCP pump; if the main pump shaft seal water is not established within 2 minutes, do not establish shaft seal water.

[0088] Perform RCV and ASG regulation operations to stabilize the primary loop temperature and pressure;

[0089] Continue to restore power supply to other power supply series via auxiliary transformers;

[0090] The plant's power supply was restored to normal operation.

[0091] The test conditions were reconfigured according to the initial state, and the test was re-executed.

[0092] Preferably, when BAS56 and BAS54 cannot be executed in the same task window, the loss of external mains power is simulated; specifically including:

[0093] Under the hot shutdown condition of the primary circuit of the unit, LGE001JA and LGF001JA are disconnected by DCS operation in the main control room.

[0094] After LGE001JA and LGF001JA are disconnected, the DCS in the main control room synchronously disconnects LGA001JA and LGD001JA, triggering LGB / C to automatically and synchronously switch to auxiliary transformer power supply.

[0095] Continue performing the BAS54 test in the auxiliary transformer power supply mode, start RCP001PO, CRF001PO, CEX001PO, SEN, SRI, CVI, CET, GGR, and GHE auxiliary equipment to maintain the primary circuit hot shutdown condition and condenser vacuum condition.

[0096] This invention also provides a nuclear power plant auxiliary power supply switching test device, which includes:

[0097] The configuration unit is used to configure the initial states of the BAS56 test and the BAS54 test in parallel. When configuring the initial state of the BAS54 test, the availability of auxiliary equipment for the primary loop hot shutdown condition and condenser vacuum condition is maintained to meet the auxiliary equipment startup requirements of the plant power supply in the auxiliary transformer power supply mode.

[0098] The BAS56 test unit is used to perform the BAS56 test and obtain the final state of the BAS56 test after the test is completed.

[0099] The fast power-off unit is used to achieve rapid power outage and restoration between adjacent units of the nuclear power plant's common load under the final state of the BAS56 test, using a fast power-off technology that mimics automatic switching.

[0100] The BAS54 test unit is used to execute the BAS54 test by using the final state of the BAS56 test as the initial state of the BAS54 test.

[0101] This invention also provides a nuclear power plant auxiliary power switching test device, which includes a memory and a processor. The memory stores a computer program, which can be executed by the processor to implement the nuclear power plant auxiliary power switching test method described above.

[0102] This embodiment achieves deep decoupling between plant power supply switching tests and grid connection tests, reducing the correlation between plant power supply switching tests and grid connection work, realizing high flexibility of the test window, further improving test efficiency, simplifying test operations, and reducing test risks. It also reduces input in areas such as manpower, plant power consumption, diesel generator fuel consumption, and demineralized water production and process wastewater treatment, saving more than two days of mainline construction time during the hot functional test phase of the nuclear power unit commissioning and startup process, resulting in significant cost reduction and efficiency improvement. Attached Figure Description

[0103] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0104] Figure 1 This is a flowchart of an existing plant power supply switching technology solution;

[0105] Figure 2 This is a schematic diagram of the auxiliary load power supply distribution for maintaining hot shutdown and condenser vacuum conditions in existing nuclear power plants.

[0106] Figure 3 This is a schematic flowchart of a nuclear power plant power supply switching test method according to the first embodiment of the present invention.

[0107] Figure 4 This is another schematic diagram of the test method for switching power supply in a nuclear power plant according to the first embodiment of the present invention.

[0108] Figure 5 This is a flowchart illustrating the rapid power-off method of 7LGI's simulated automatic switching.

[0109] Figure 6 This is a flowchart illustrating the emergency plan for low primary circuit temperature.

[0110] Figure 7 This is a schematic diagram of the handling process when the plant power supply switching fails.

[0111] Figure 8 A schematic diagram of the process for simulating the loss of external main power supply technology.

[0112] Figure 9 This is a schematic diagram of the nuclear power plant power supply switching test device according to the second embodiment of the present invention. Detailed Implementation

[0113] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. 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. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to represent selected embodiments of the invention. 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.

[0114] This invention provides a method, apparatus, and equipment for testing the switching of power supply to a nuclear power plant, aiming to reduce the correlation between the power supply switching test and grid operation, decouple the BAS54 test from grid-related operations, improve the flexibility of work window scheduling, reduce test operation risks, improve work efficiency, and reduce work cost input.

[0115] Specifically, in the BAS56 test, to verify that the residual voltage U of LGB / C drops to 0.4UN in less than 1.5 seconds during the switching between the plant transformer and the auxiliary transformer, the load should be put into operation as much as possible before the test to verify this item under extreme conditions. During the BAS56 test, the unit's common switchboard 7LGI needs to be powered by the test unit. However, in the BAS54 test, due to the power supply mode of the auxiliary transformer, when the auxiliary transformer needs to power the main pump to start, 7LGI needs to be switched to the power supply of the adjacent unit. During the hot test, after the plant power supply is switched to the auxiliary transformer, since there is no residual heat in the reactor core, and after the main pump stops operating, the reactor core loses its heat source. In addition, the primary loop's natural heat dissipation cools down, and the temperature and pressure of the primary loop will slowly decrease. In severe cases, the temperature and pressure of the primary loop may exceed the operating parameter limits, leading to serious consequences such as the unexpected triggering of the reactor protection system. If the conventional power-off mode is followed and the operating power-off procedures are strictly implemented, this will inevitably continue for a long time. To achieve coupling between BAS56 and BAS54, after the unit's status stabilizes following the switch of the plant power supply to the auxiliary transformer, the 7LGI switchover to the adjacent unit's power supply operation must be executed immediately.

[0116] In response to the special situation where BAS56 and BAS54 are executed under two task windows, and in order to achieve deep decoupling between BAS54 and grid-connected operations, the operating conditions of nuclear power units losing external main power supply are fully simulated. This is to enable the continued execution of auxiliary equipment such as RCP001PO, CRF001PO, CEX001PO, SEN, SRI, CVI, CET, GGR, and GHE in auxiliary transformer power supply mode, so as to maintain the primary loop hot shutdown condition and condenser vacuum conditions.

[0117] To facilitate understanding of the present invention, a more detailed description is provided below. First, some technical terms related to the present invention will be explained.

[0118] BAS Electrical Power Supply Changeover Test

[0119] ASG Auxiliary Feedwater System

[0120] RCP Reactor Cooling System

[0121] RCV Chemical and Volume Control System

[0122] RRI Equipment Cooling Water System

[0123] SEC Essential Service Water System

[0124] CRF Circulating Water System

[0125] CEX Condensate Extraction System

[0126] GGR Turbine Lubrication, Jacking and Turning System

[0127] GHE Generator Seal Oil System

[0128] CVI Condenser Vacuum System

[0129] SEN Auxiliary Cooling Water System

[0130] SRI Conventional Island Closed Cooling Water System

[0131] CET Turbine Gland System

[0132] GEV Power Transmission System

[0133] GEW 500kV Extra High Voltage Distribution System

[0134] LGA, LGB, LGC, LGD, LGE, LGF: Conventional Island Medium-Voltage Normal Distribution System (CI)

[0135] LGB001JA, LGC001JA Conventional Island Medium-Voltage Normal Distribution System Auxiliary Normal Transformer Power Side Tie Breaker of CI Medium-Voltage Normal Distribution System

[0136] LGB102JA and LGC102JA are standard island medium-voltage normal distribution system auxiliary power side incoming switches.

[0137] 7LGJ BOP Medium-Voltage Normal Switchboard

[0138] LHA and LHB Nuclear Island Medium-Voltage Distribution Board Emergency Power Supply System

[0139] LHP Medium-Voltage AC Emergency Power Supply - Diesel Train A

[0140] LHQ Medium-Voltage AC Emergency Power Supply - Diesel Series B

[0141] GPA Generator and Transmission Protection System

[0142] TS stands for Auxiliary Normal Transformer.

[0143] TA (Standby Transformer) is a type of auxiliary transformer used in industrial plants.

[0144] Auxiliary power supplies include normal power, auxiliary power, and emergency power.

[0145] Distributed Control System (or Digital Control System)

[0146] Please see Figure 3 and Figure 4 As shown, the first embodiment of the present invention provides a test method for switching power supplies in a nuclear power plant, which includes:

[0147] S101, configure the initial states of BAS56 test and BAS54 test in parallel; when configuring the initial state of BAS54 test, maintain the availability of auxiliary equipment under primary circuit hot shutdown condition and condenser vacuum condition, and meet the auxiliary equipment start-up requirements of plant power supply under auxiliary transformer power supply mode.

[0148] S102, perform the BAS56 test, and obtain the final state of the BAS56 test after the BAS56 test is completed.

[0149] The specific steps for performing the BAS56 test are as follows:

[0150] Disconnect the 500kV ultra-high voltage switch from the normal power supply outside the plant;

[0151] The GPA protection action is activated, automatically switching the plant power supply to the auxiliary transformer power supply;

[0152] Restore the 500kV ultra-high voltage switch to normal power supply outside the plant, restore the main transformer to operation, and reset the GPA protection.

[0153] Complete the BAS56 test.

[0154] S103, under the final state of the BAS56 test, adopts a rapid power-off technology that mimics automatic switching to achieve rapid power outage and restoration between adjacent units of the nuclear power plant's common load.

[0155] Among them, such as Figure 5 As shown, for the unit's common switchboard 7LGI, the fast power-off technology using simulated automatic switching specifically includes:

[0156] It has been confirmed that the downstream medium-voltage rotating loads supplied by 7LGI have been shut down;

[0157] The test position opening and closing operation of 7LGIB001JA was verified using a test kit.

[0158] Set 7LGIB001JA to the working position, ready for power-off operation;

[0159] Disconnect 7LGIA001JA, confirm that 7LGI is de-energized, and after a predetermined time (e.g., 3 seconds), close 7LGIB001JA locally. 7LGI will then switch power to the adjacent unit's LGC for operation.

[0160] In this embodiment, if 7LGIB001JA fails to close, it indicates that 7LGI failed to switch to the adjacent unit LGC for power supply. In this case, the 7LGIA001JA switch is disconnected and placed in the isolation position. The DC power supply of the 7LGIA001JA switch is disconnected, and the operation of 7LGI being powered by 7LGIB is executed.

[0161] Restore the downstream medium-voltage rotating load powered by 7LGI.

[0162] S104, using the final state of the BAS56 test as the initial state of the BAS54 test, execute the BAS54 test.

[0163] In this embodiment, the steps of the BAS54 test include:

[0164] Operate the LGA / D to switch to auxiliary transformer power supply operation, and start the primary circuit equipment and secondary circuit equipment in sequence.

[0165] The primary circuit equipment includes RCP001PO, a voltage regulator electric heater; the secondary circuit equipment includes: CRF001PO, CEX001PO, SEN, SRI, CVI, CET, GGR, and GHE.

[0166] Switch the plant's auxiliary power supply back to the plant transformer, restore the plant's auxiliary equipment, and restore the unit to the thermal power plant shutdown state;

[0167] Complete the BAS54 test.

[0168] In summary, this embodiment achieves deep decoupling between plant power supply switching tests and grid connection tests, reducing the correlation between plant power supply switching tests and grid connection work, realizing high flexibility of the test window, further improving test efficiency, simplifying test operations, and reducing test risks. It also reduces input in areas such as manpower, plant power consumption, diesel generator fuel consumption, and demineralized water production and process wastewater treatment, saving more than two days of mainline construction time during the hot functional test phase of the nuclear power unit commissioning and startup process, resulting in significant cost reduction and efficiency improvement.

[0169] To facilitate understanding of the present invention, some preferred embodiments of the present invention are described in further detail below:

[0170] In the above embodiments, the significant adjustment to the test logic sequence also increases the risks that need to be considered during test execution. Although the power-off operation of 7LGI is simplified, the test may still face the risk of the primary circuit temperature dropping to the threshold due to excessive duration, requiring manual intervention by the operator. Therefore, in this preferred embodiment, as... Figure 6 As shown, the emergency operation for low primary circuit temperature is as follows:

[0171] Before the test begins, the primary circuit temperature should be appropriately increased. During the test, the primary circuit temperature should be closely monitored. When the primary circuit temperature drops to the warning value, to prevent the primary circuit temperature from continuing to drop, the RCP001PO should be started via the auxiliary transformer to maintain the primary circuit temperature. If this is not feasible, the power supply from the GEV to the medium-voltage power distribution system should be restored as soon as possible so that operators can manually start one or more main pumps via the main power supply to maintain the temperature and pressure of the primary circuit.

[0172] During the power supply switching process, automatic power switching may fail. To ensure the main pump shaft seal and thermal shield are not lost, such as... Figure 7 As shown, this embodiment also includes:

[0173] In the initial test state, the LHP and LHQ emergency diesel generators are in hot standby mode to ensure that when the plant power supply fails to switch to the auxiliary transformer, the LHP / LHQ emergency generators will automatically start and supply power to the main pump shaft seal and related equipment.

[0174] When the LGB fails to switch to the auxiliary transformer, the unit status will be managed according to the following contingency plan:

[0175] The inspection confirmed that the LHA is powered by the emergency diesel generator LHP.

[0176] Check and confirm that RCV / RRI / SEC continues to operate;

[0177] Perform RCV and ASG regulation operations to stabilize the primary loop temperature and pressure;

[0178] LGB is now powered by the auxiliary transformer.

[0179] Restore GEW / GEV power supply;

[0180] The plant's power supply was restored to normal operation.

[0181] The test was re-executed with the test conditions reconfigured according to the initial state.

[0182] When the switching from LGC to the auxiliary transformer fails, the unit status will be managed according to the following contingency plan:

[0183] The inspection confirmed that LHB is powered by the emergency diesel generator LHQ.

[0184] Check and confirm that RCV / RRI / SEC continues to operate;

[0185] Perform RCV and ASG regulation operations to stabilize the primary loop temperature and pressure;

[0186] Restore power supply to LGC from the auxiliary transformer;

[0187] Restore GEW / GEV power supply;

[0188] The plant's power supply was restored to normal operation.

[0189] The test was re-executed with the test conditions reconfigured according to the initial state.

[0190] When both LGB / LGC and auxiliary transformer switching fail, the unit status will be managed according to the following contingency plan:

[0191] The inspection confirmed that the LHA is powered by the emergency diesel generator LHP.

[0192] The inspection confirmed that LHB is powered by the emergency diesel generator LHQ.

[0193] Check and confirm that RCV / RRI / SEC continues to operate;

[0194] Perform RCV and ASG regulation operations to stabilize the primary loop temperature and pressure;

[0195] LGB is now powered by the auxiliary transformer.

[0196] Restore power supply to LGC from the auxiliary transformer;

[0197] Restore GEW / GEV power supply;

[0198] The plant's power supply was restored to normal operation.

[0199] The test conditions were reconfigured according to the initial state, and the test was re-executed.

[0200] When the LHA to LHP switch fails, the unit status shall be managed and controlled according to the following contingency plan:

[0201] The inspection confirmed that LHB is powered by the emergency diesel generator LHQ.

[0202] Check and confirm that RCV / RRI / SEC continues to operate;

[0203] Perform RCV and ASG regulation operations to stabilize the primary loop temperature and pressure;

[0204] LGB is now powered by the auxiliary transformer.

[0205] Restore GEW / GEV power supply;

[0206] The plant's power supply was restored to normal operation.

[0207] The test was re-executed with the test conditions reconfigured according to the initial state.

[0208] When the switch from LHB to LHQ fails, the unit status will be managed according to the following contingency plan:

[0209] The inspection confirmed that the LHA is powered by the emergency diesel generator LHP.

[0210] Check and confirm that RCV / RRI / SEC continues to operate;

[0211] Perform RCV and ASG regulation operations to stabilize the primary loop temperature and pressure;

[0212] Restore power supply to LGC from the auxiliary transformer;

[0213] Restore GEW / GEV power supply;

[0214] The plant's power supply was restored to normal operation.

[0215] The test conditions were reconfigured according to the initial state, and the test was re-executed.

[0216] When the switch from LHA / LHB to LHP / LHQ fails, the unit enters SBO mode, and the unit status is managed according to the following plan:

[0217] Before the test, RRI / SEC was configured to run in two columns, and the inter-column backup function was enabled.

[0218] Record the status of the RCV equipment before the test;

[0219] Restore power supply from LGB / LHA to the auxiliary transformer or restore power supply from LGC / LHB to the auxiliary transformer;

[0220] Check to confirm that RCV / RRI / SEC is still running; otherwise, start it manually.

[0221] Check the seal injection flow rate of the RCP pump; if the main pump shaft seal water is not established within 2 minutes, do not establish shaft seal water.

[0222] Perform RCV and ASG regulation operations to stabilize the primary loop temperature and pressure;

[0223] Continue to restore power supply to other power supply series via auxiliary transformers;

[0224] The plant's power supply was restored to normal operation.

[0225] The test conditions were reconfigured according to the initial state, and the test was re-executed.

[0226] To address the unique situation where BAS56 and BAS54 operate under two different task windows, a simulation solution for the loss of external main power supply can be adopted. This fully simulates the operating conditions of a nuclear power unit without external main power supply, reducing the correlation between the BAS54 test and grid-related operations, and achieving complete decoupling between the BAS54 test and grid-related operations. Figure 8 As shown, the simulated power loss simulation technology provided in this preferred embodiment specifically includes:

[0227] Under the hot shutdown condition of the primary circuit of the unit, LGE001JA and LGF001JA are disconnected by DCS operation in the main control room.

[0228] After LGE001JA and LGF001JA are disconnected, the DCS in the main control room synchronously disconnects LGA001JA and LGD001JA, triggering LGB / C to automatically and synchronously switch to auxiliary transformer power supply.

[0229] Continue performing the BAS54 test in the auxiliary transformer power supply mode, and start the auxiliary equipment RCP001PO, CRF001PO, CEX001PO, SEN, SRI, CVI, CET, GGR, and GHE to maintain the primary circuit hot shutdown condition and condenser vacuum condition.

[0230] Please see Figure 9 The second embodiment of the present invention also provides a nuclear power plant auxiliary power switching test device, which includes:

[0231] Configuration unit 210 is used to configure the initial state of BAS56 test and BAS54 test in parallel; wherein, when configuring the initial state of BAS54 test, the availability of auxiliary equipment for primary loop hot shutdown condition and condenser vacuum condition is maintained to meet the auxiliary equipment start-up requirements of plant power supply in auxiliary transformer power supply mode.

[0232] BAS56 test unit 220 is used to perform BAS56 test and obtain the final state of BAS56 test after the BAS56 test is completed;

[0233] The fast power-off unit 230 is used to achieve rapid power outage and restoration between adjacent units of the nuclear power plant's common load under the final state of the BAS56 test by using fast power-off technology that mimics automatic switching.

[0234] BAS54 test unit 240 is used to perform BAS54 test by using the final state of BAS56 test as the initial state of BAS54 test.

[0235] The third embodiment of the present invention also provides a nuclear power plant auxiliary power switching test device, which includes a memory and a processor. The memory stores a computer program, which can be executed by the processor to realize the nuclear power plant auxiliary power switching test method as described above.

[0236] In the several embodiments provided by this invention, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus and method embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0237] In addition, the functional modules in the various embodiments of the present invention can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0238] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, electronic device, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks. It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further restrictions, an element defined by the phrase "comprising a..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0239] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of testing a nuclear power plant station service power switch, characterized by, The method comprises the following steps: The parallel configuration BAS56 test and the initial state of the BAS54 test are performed; wherein, when the initial state of the BAS54 test is configured, the auxiliary equipment under the condition of the heat shutdown of the primary loop and the condenser vacuum is maintained in the available state, and the auxiliary equipment starting requirement of the auxiliary power supply under the auxiliary variable power supply mode is met; The BAS56 test is performed, and the final state of the BAS56 test is obtained after the BAS56 test is completed; In the final state of the BAS56 test, the adjacent unit fast shutdown and power supply of the nuclear power unit public load are realized by using the fast power reversal technology of the automatic switching simulation, and the specific steps comprise the following steps: confirming that the downstream medium-pressure rotating load of the 7LGI power supply is shut down; verifying the 7LGIB001JA test point opening and closing operation by using a test box; placing the 7LGIB001JA in the working position and preparing for the power reversal operation; disconnecting the 7LGIA001JA, confirming that the 7LGI loses power, locally closing the 7LGIB001JA after a predetermined time, and reversing the power of the 7LGI to the adjacent unit LGC power supply operation; wherein, when the 7LGIB001JA closing is unsuccessful and the 7LGI fails to be switched to the adjacent unit LGC power supply, the 7LGIA001JA switch is disconnected and is placed in the isolation position, the 7LGIA001JA switch DC power supply is disconnected, the 7LGI power supply operation from the 7LGIB is performed, and the downstream medium-pressure rotating load of the 7LGI power supply is restored; The final state of the BAS56 test is taken as the initial state of the BAS54 test, and the BAS54 test is performed.

2. The nuclear power plant auxiliary power source switching test method according to Claim 1, characterized by, The steps of performing the BAS56 test are specifically as follows: Disconnecting the 500kV extra-high voltage switch of the external normal power supply; Starting the GPA protection action to automatically switch the auxiliary variable power supply of the auxiliary power supply; Restoring the 500kV extra-high voltage switch of the external normal power supply, restoring the main transformer operation, and resetting the GPA protection; Completing the BAS56 test.

3. The nuclear power plant auxiliary power source switching test method according to Claim 1, characterized by, The steps of performing the BAS54 test comprise the following steps: Operating the LGA / LGD switching to the auxiliary variable power supply operation, and starting the primary loop equipment and the secondary loop equipment in sequence; Switching the auxiliary power supply back to the plant variable power supply, restoring the auxiliary power supply equipment, and restoring the unit to the heat and electricity shutdown state; Completing the BAS54 test.

4. The nuclear power plant auxiliary power source switching test method according to Claim 1, characterized by Further comprising the following steps: When the primary loop temperature drops to the pre-warning value, starting the RCP001PO through the auxiliary variable to maintain the primary loop temperature; If it is not feasible, restoring the GEV to supply power to the medium-voltage distribution system, so that the operator can start one or more main pumps through the main power supply to maintain the temperature and pressure of the primary loop.

5. The nuclear power plant auxiliary power source switching test method according to Claim 1, characterized by, Further comprising the following steps: In the initial state of the test, the LHP and the LHQ emergency diesel generator are in the hot standby state, so as to ensure that when the auxiliary power supply switching fails, the LHP / LHQ emergency automatically starts and supplies power to the main pump shaft seal and the heat shield related equipment.

6. The nuclear power plant auxiliary power supply switching test method according to claim 5, wherein, When the LGB switching to the auxiliary variable fails, the unit state is controlled according to the following plan: Confirming that the LHA is powered by the emergency diesel generator LHP; Confirming that the RCV / RRI / SEC continues to operate; Performing the RCV and ASG adjustment operation to stabilize the temperature and pressure of the primary loop; Restoring the LGB power supply from the auxiliary variable; Restoring the GEW / GEV power supply; The emergency power supply is supplied by the emergency diesel generator; The test is re-executed according to the initial state.

7. The nuclear power plant auxiliary power supply switching test method according to claim 5, wherein, When the LGC fails to switch to the auxiliary variable, the unit state is controlled according to the following plan: Check and confirm that the LHB is supplied by the emergency diesel generator LHQ; Check and confirm that the RCV / RRI / SEC continues to operate; Perform RCV and ASG adjustment operations to stabilize the primary loop temperature and pressure; Restore LGC power supply by the auxiliary variable; Restore GEW / GEV power supply; Restore the emergency power supply by the normal power supply; The test is re-executed according to the initial state.

8. The nuclear power plant auxiliary power supply switching test method according to claim 5, wherein, When the LGB / LGC fails to switch to the auxiliary variable, the unit state is controlled according to the following plan: Check and confirm that the LHA is supplied by the emergency diesel generator LHP; Check and confirm that the LHB is supplied by the emergency diesel generator LHQ; Check and confirm that the RCV / RRI / SEC continues to operate; Perform RCV and ASG adjustment operations to stabilize the primary loop temperature and pressure; Restore LGB power supply by the auxiliary variable; Restore LGC power supply by the auxiliary variable; Restore GEW / GEV power supply; Restore the emergency power supply by the normal power supply; The test is re-executed according to the initial state.

9. The nuclear power plant auxiliary power supply switching test method according to claim 5, wherein, When the LHA fails to switch to the LHP, the unit state is controlled according to the following plan: Check and confirm that the LHB is supplied by the emergency diesel generator LHQ; Check and confirm that the RCV / RRI / SEC continues to operate; Perform RCV and ASG adjustment operations to stabilize the primary loop temperature and pressure; Restore LGB power supply by the auxiliary variable; Restore GEW / GEV power supply; Restore the emergency power supply by the normal power supply; The test is re-executed according to the initial state.

10. The nuclear power plant auxiliary power supply switching test method according to claim 5, wherein, When the LHB fails to switch to the LHQ, the unit state is controlled according to the following plan: Check and confirm that the LHA is supplied by the emergency diesel generator LHP; Check and confirm that the RCV / RRI / SEC continues to operate; Perform RCV and ASG adjustment operations to stabilize the primary loop temperature and pressure; Restore LGC power supply by the auxiliary variable; Restore GEW / GEV power supply; Restore the emergency power supply by the normal power supply; The test is re-executed according to the initial state.

11. The nuclear power plant auxiliary power supply switching test method according to claim 5, wherein, When the LHA / LHB fails to switch to the LHP / LHQ, the unit enters SBO condition, and the unit state is controlled according to the following plan: Before the test, configure the RRI / SEC to operate in two columns, and put the inter-column standby function into operation; Before the test, record the RCV equipment state; Restore LGB / LHA to the auxiliary variable power supply or restore LGC / LHB to the auxiliary variable power supply; Check and confirm that the RCV / RRI / SEC continues to operate, otherwise manually start; Check the seal injection flow of the pump in the RCP; wherein, if the main pump shaft seal water is not established within 2 minutes, the shaft seal water is not established again; Perform the RCV and ASG adjustment operation to stabilize the primary loop temperature and pressure; Continue to restore the other power supply series to be powered by the auxiliary variable power supply; Restore the station power supply to be powered by the normal power supply to operate; Reconfigure the test conditions according to the initial state and re-execute the test.

12. The nuclear power plant auxiliary power source switching test method according to Claim 3, characterized by, Further comprising: Simulate the loss of the external main power supply when the BAS56 and the BAS54 cannot be executed in the same task window; The simulation of the loss of the external main power supply specifically comprises: Under the unit primary loop hot shutdown condition, use the main control room DCS to operate to disconnect the LGE001JA and the LGF001JA; After the LGE001JA and the LGF001JA are disconnected, use the main control room DCS to synchronously operate to disconnect the LGA001JA and the LGD001JA to trigger the LGB / LGC automatic synchronous switching to the auxiliary variable power supply; Continue to execute the BAS54 test in the auxiliary variable power supply mode, start the RCP001PO, the CRF001PO, the CEX001PO, the SEN, the SRI, the CVI, the CET, the GGR, and the GHE auxiliary equipment to maintain the primary loop hot shutdown condition and the condenser vacuum condition.

13. A nuclear power plant auxiliary power switching test device characterized by comprising: Comprise: A configuration unit is configured to configure the initial state of the BAS56 test and the BAS54 test in parallel; wherein, when the initial state of the BAS54 test is configured, the available state of the auxiliary equipment for maintaining the primary loop hot shutdown condition and the condenser vacuum condition is maintained, and the auxiliary equipment start requirement of the station power supply in the auxiliary variable power supply mode is met; A BAS56 test unit is configured to execute the BAS56 test, and obtain the final state of the BAS56 test after the BAS56 test is executed; A fast black start unit is configured to use the fast black start technology of the automatic switching to realize the fast black start and stop of the adjacent units of the nuclear power plant station public load, specifically comprising: confirming that the downstream medium voltage rotating load of the 7LGI power supply has been stopped; using the test box to verify the opening and closing operation of the 7LGIB001JA test point; placing the 7LGIB001JA in the working position to prepare for the black start operation; disconnecting the 7LGIA001JA, confirming that the 7LGI loses power, locally closing the 7LGIB001JA after a predetermined time, and black starting the 7LGI to the adjacent unit LGC power supply operation; wherein, when the 7LGIB001JA fails to close, the 7LGI fails to switch to the adjacent unit LGC power supply, the 7LGIA001JA switch has been disconnected and placed in the isolation position, the 7LGIA001JA switch DC power supply is disconnected, the 7LGI is powered by the 7LGIB, and the downstream medium voltage rotating load of the 7LGI power supply is restored. A BAS54 test unit is configured to execute the BAS54 test with the final state of the BAS56 test as the initial state of the BAS54 test.

14. A nuclear power plant station service power switching test apparatus characterized by comprising: The nuclear power plant station power supply switching test method comprises a memory and a processor, the memory stores a computer program which can be executed by the processor to realize the nuclear power plant station power supply switching test method.

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