A nuclear power plant generator unit protection and grid-connected protection cooperation verification system and method

Abstract

A system and method for verifying the coordination between generator protection and grid protection in a nuclear power plant includes an electrical simulation device, a power unit, a first junction box, a generator-transformer protection device, a second junction box, and a grid protection device. The verification method of this application verifies the coordination between the generator's grid protection and the grid system by adding voltage and current values ​​to the generator-transformer protection device and the grid protection device. The input voltage and current values ​​are calculated by the electrical simulation system, resulting in objective, accurate, and highly reliable verification results. Furthermore, the method is simple to operate, with wiring methods and current transformer polarities set entirely according to actual site conditions, enabling the detection of errors in the circuit and providing a more comprehensive verification.

Description

Technical Field

[0001] This invention relates to the field of generator set verification technology, specifically to a verification system and method for the coordinated protection of nuclear power plant generator sets and grid-connected protection. Background Technology

[0002] The generator is equipped with a microprocessor-based generator protection device, the transformer is equipped with a microprocessor-based transformer protection device, and the 500kV power grid is equipped with corresponding power grid protection. The microprocessor-based generator protection, transformer protection, and 500kV power grid protection collect and calculate electrical quantities such as voltage, current, and power of the generator in real time. When the generator, transformer, or 500kV power grid equipment malfunctions or operates abnormally, the corresponding protection device will be activated, tripping the corresponding switch of the faulty equipment, switching or isolating the faulty equipment from the system, and ensuring the safe and stable operation of the equipment.

[0003] For abnormal operating modes of nuclear power plant generators, such as reduced excitation current, rotor winding overcurrent, out-of-step operation, loss of turbine speed control, overexcitation, voltage anomalies, and abnormal tripping of auxiliary equipment, the relay protection devices of nuclear power plant generator transformer units are typically equipped with functions such as loss of excitation, rotor winding overload, out-of-step operation, turbine overspeed, overexcitation, stator overvoltage, stator undervoltage, overexcitation limitation, and protection for important auxiliary equipment. The 500kV power grid, based on abnormal or fault conditions of lines and busbars, is equipped with line protection, busbar protection, stability devices, out-of-step disconnection devices, and other protection and safety automatic devices in its power grid protection system. The protection and control devices of nuclear power units have actions and parameter settings related to power grid operation and need to be coordinated with the grid-side safety automatic devices. For example, excessively low or high generator operating frequencies can easily damage turbine blades. For turbine safety, large turbine generators are generally equipped with frequency anomaly protection. For the power grid, frequency and voltage emergency control devices, which take measures such as generator tripping and load shedding during system frequency anomalies and other accidents to prevent system collapse, are an important component of the power system's third line of defense. To ensure that generators do not trip beyond their designated cascading protection level during system frequency anomalies, thus reducing their support capacity for the system, there is a coordination relationship between the unit's frequency anomaly protection and the grid's frequency and voltage emergency control devices. Generator low-frequency protection should coordinate with the grid's low-frequency load shedding device, and the low-frequency protection setting should be lower than the last set value of the grid's low-frequency load shedding device. Generator over-frequency protection should coordinate with the grid's high-frequency generator tripping device, following the principle that high-frequency tripping should act before over-frequency protection. To ensure the safe, high-quality, and economical operation of the power grid system, unit grid-connected protection and grid protection should coordinate and cooperate. During grid faults, units should operate stably without tripping beyond their designated cascading protection level, providing stable support for the grid system. Grid-connected protection should act promptly during unit faults without threatening grid safety.

[0004] At present, the method of calculating the protection settings is usually used to verify the coordination between generator grid protection and power grid system protection. This method has the following disadvantages: (1) The accuracy of manual setting calculation may be affected by the error of the protection organization's setting parameters, the difference of different protection principles of different protection manufacturers' equipment, etc. The level of personal protection setting technology also has a decisive impact on the calculation results, and the reliability is not high; (2) Since no actual on-site verification is carried out, the actual wiring errors of the protection device and the reverse polarity of the current secondary circuit cannot be detected in time, and the verification accuracy is not high. Summary of the Invention

[0005] The purpose of this invention is to provide a system and method for verifying the coordination between nuclear power plant generator set protection and grid-connected protection, thereby solving the problems of low stability, low accuracy, and high technical threshold of existing protection setting coordination verification methods.

[0006] The technical solution of the present invention is as follows: a nuclear power plant generator set protection and grid-connected protection coordination verification system, comprising an electrical simulation device, a power unit, a first junction box, a generator-transformer set protection device, a second junction box, and a grid protection device; The electrical simulation device includes a control console, a signal output module, and a signal input module. The power unit includes a power unit signal input module, a power unit signal output module, a power unit signal input module A, a power unit power output module, and a power unit signal input module B; The generator-transformer protection device includes the wiring terminals of the generator-transformer protection device, the output terminals of the generator-transformer protection device, and the wiring terminals of the generator-transformer protection device. Power grid protection devices include the wiring terminals and output terminals of the power grid protection devices; The signal output module is connected to the signal input module of the power unit in the power unit. The signal output module of the power unit in the power unit is connected to the signal input module of the electrical simulation system in the electrical simulation device. The power output module of the power unit is connected to the first junction box. The first junction box is connected to the wiring terminal of the generator-transformer group protection device. The wiring terminal of the generator-transformer group protection device is connected to the second junction box. The second junction box is connected to the wiring terminal of the power grid protection device. The output terminal of the generator-transformer protection device is connected to the signal input module A of the power unit, and the output terminal of the power grid protection device is connected to the signal input module B of the power unit. A method for verifying the coordination between nuclear power plant generator unit protection and grid-connected protection includes the following steps: Step 1: Input the electrical parameters of the generator and transformer in the control panel of the electrical simulation system, input the protection settings in the generator-transformer group protection device, and input the protection settings in the power grid protection device.

[0007] Step 2: Run the operating condition simulation. Set different operating conditions of the generator in the control console of the electrical simulation system. The signal output module of the electrical simulation system sends the control signal to the signal input module of the power unit. The power unit 5 sends the power signal according to the collected control signal. The power output module of the power unit sends the signal to the terminal of the generator-transformer protection device through the first junction box. The power signal then passes through the terminal of the generator-transformer protection device and is sent to the terminal of the grid protection device through the second junction box. Step 3: Sample value check. Start the sample value check in the electrical simulation console. The power signal received by the power unit's signal input module is sent to the generator-transformer group protection device and the grid protection device through the power unit's power output module. Check and record the sample values ​​of the generator-transformer group protection device and the grid protection device. Step 4: Sampling value error judgment. The output terminals of the generator-transformer protection device and the power grid protection device send their respective protection action information to the signal input module A and signal input module B of the power unit, respectively. The power unit sends the collected action signal to the signal input module of the electrical simulation system through the signal output module of the power unit. The sampled value of the action signal is compared with the power signal sent by the simulation system. If the error is less than or equal to 2.0%, proceed to step 5. Step 5: Protection verification. Set the protection type to be verified in the electrical simulation device control panel. The electrical simulation device sends a power signal according to the set protection type. The generator-transformer group protection device and the power grid protection device start to operate according to the received power signal. Step Six: Begin determining the protection coordination relationship. The output terminals of the generator-transformer protection device and the power grid protection device send the action information of the protection device to the signal input module A and signal input module B of the power unit, respectively. The power unit sends the received action information to the signal input module of the electrical simulation system through the signal output module of the power unit. The electrical device determines whether the protection meets the coordination relationship based on the received action information and the protection type in Step Five.

[0008] In step two, the generator is set to run under no-load, 25%, 50%, 75%, and 100% rated load conditions in the electrical simulation control panel.

[0009] In step four, if the error is greater than 2.0%, proceed to error cause analysis, check the wiring and parameter settings of the generator-transformer group protection device and the power grid protection device, make adjustments, and then repeat the sampling value check in step three.

[0010] In step six, if the protection does not meet the coordination requirements, the analysis of the reasons for the protection coordination is performed. The protection settings of the generator-transformer group protection device and the power grid protection device are modified, and the protection verification in step five is performed again.

[0011] In step six, if the protections meet the matching requirements, the verification ends.

[0012] In step five, different protection types are set in the electrical simulation device control console for different types of generator grid protection and grid protection verification.

[0013] The protection verification in step five, the determination of protection coordination relationships in step six, and the analysis of the causes of protection coordination are carried out in a loop until all protection verifications are completed.

[0014] The significant advantages of this invention are: (1) The verification method of the present invention uses voltage and current to verify the grid protection of generators and grid system by adding voltage and current to the generator-transformer protection device and grid protection device. The input voltage and current values ​​are calculated by the electrical simulation system. The verification results are objective, accurate and reliable. Moreover, the method is simple to operate and does not require high technical skills from personnel.

[0015] (2) The verification method of the present invention uses the actual addition of relevant analog quantities for verification, and the wiring method and current transformer polarity are completely set according to the actual site conditions, which can detect errors in the circuit and make the verification more comprehensive. Attached Figure Description

[0016] Figure 1 Schematic diagram of the nuclear power plant generator unit protection and grid-connected protection coordination verification system; The markings in the diagram and their corresponding component names are as follows: 1 Electrical simulation device, 2 Control console of electrical simulation device, 3 Signal output module of electrical simulation system, 4 Signal input module of electrical simulation system, 5 Power unit, 6 Signal input module of power unit, 7 Signal output module of power unit, 8 Signal input module A of power unit, 9 Power output module of power unit, 10 Signal input module B of power unit, 11 First junction box, 12 Generator-transformer group protection device, 13 Wiring terminal of generator-transformer group protection device, 14 Output terminal of generator-transformer group protection device, 15 Wiring terminal of generator-transformer group protection device, 16 Second junction box, 17 Power grid protection device, 18 Wiring terminal of power grid protection device, 19 Output terminal of power grid protection device. Detailed Implementation

[0017] Many specific details are set forth in the following description to provide a full understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of this application; therefore, this application is not limited to the specific embodiments disclosed below.

[0018] The terminology used in one or more embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the scope of one or more embodiments of this application. The singular forms “a,” “the,” and “the” used in one or more embodiments of this application and in the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” used in one or more embodiments of this application refers to and includes any or all possible combinations of one or more associated listed items.

[0019] It should be understood that although the terms first, second, etc., may be used to describe various information in one or more embodiments of this application, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first may also be referred to as second without departing from the scope of one or more embodiments of this application, and similarly, second may also be referred to as first.

[0020] The specific technical content of the present invention will now be described with reference to the accompanying drawings; A nuclear power plant generator set protection and grid protection coordination verification system includes an electrical simulation device 1, a power unit 5, a first junction box 11, a generator-transformer set protection device 12, a second junction box 16, and a grid protection device 17.

[0021] The electrical simulation device 1 includes a control console 2, a signal output module 3, and a signal input module 4 of the electrical simulation system; The power unit 5 includes a power unit signal input module 6, a power unit signal output module 7, a power unit signal input module A8, a power unit power output module 9, and a power unit signal input module B10. The generator-transformer protection device 12 includes a wiring terminal 13, an output terminal 14, and a wiring terminal 15. The power grid protection device 17 includes a wiring terminal 18 and an output terminal 19. Signal output module 3 is connected to signal input module 6 of power unit 5, signal output module 7 of power unit 5 is connected to signal input module 4 of electrical simulation system in electrical simulation device 1, power output module 9 of power unit is connected to first junction box 11, first junction box 11 is connected to terminal 13 of generator-transformer group protection device, terminal 15 of generator-transformer group protection device is connected to second junction box 16, and second junction box 16 is connected to terminal 18 of grid protection device. The output terminal 14 of the generator-transformer protection device is connected to the signal input module A8 of the power unit, and the output terminal 19 of the power grid protection device is connected to the signal input module B10 of the power unit. In the electrical simulation control console 2, the generator is set to operate under no-load, and at 25%, 50%, 75%, and 100% rated load conditions. The signal output module 3 of the electrical simulation device sends control signals to the signal input module 6 of the power unit. The power unit outputs a power signal based on the acquired control signal, which is transmitted through the power output module 9 and junction box 11 to the terminal 13 of the generator-transformer protection device 12. The power signal then passes through terminal 15 and junction box 16 to the terminal of the grid protection device 17. Sampling value checking is then initiated in the electrical simulation control console 2. The power unit 5 outputs a power signal based on the signal received from the signal input module 6, which is transmitted through the power output module 9 to the generator-transformer protection device 12 and the grid protection device 17. The sampling values ​​of the generator-transformer protection device 12 and the grid protection device 17 are checked and recorded. For sampling value error judgment, the output terminals 14 of the generator-transformer unit protection device 12 and 19 of the grid protection device 17 send their respective protection action information to the signal input modules 8 and 10 of the power unit. The power unit sends the collected action signal to the signal input module 4 of the electrical simulation device via the signal output module 7. The measured sampling value is compared with the power signal emitted by the simulation system device 1. If the error is greater than 2.0%, the error cause analysis is performed. The wiring and parameter settings of the generator-transformer unit protection device 12 and the grid protection device 17 are checked and adjusted, and the sampling value is checked again. If the error is not greater than 2.0%, the protection verification is performed. The protection type to be verified is set in the control console 2 of the electrical simulation device. The electrical simulation device emits a power signal according to the set protection type, and the generator-transformer unit protection device 12 and the grid protection device 17 start operating according to the received power signal. The protection coordination relationship determination begins. The output terminals 14 and 17 of the generator-transformer unit protection device 12 and the power grid protection device 17 respectively send the protection device's action information to the signal input modules 8 and 10 of the power unit. The power unit 5 then sends the received action information to the signal input module 4 of the electrical simulation device via the signal output module 7. The electrical device 1 determines whether the protection meets the coordination requirements based on the received action information and the selected protection type during protection verification. If the protection coordination relationship determination does not meet the logical requirements, a protection coordination cause analysis is performed, and the protection settings of the generator-transformer unit protection device 12 and the power grid protection device 17 are modified before re-verification. When the protection coordination relationship determination meets the logical requirements, the generator grid protection and power grid system coordination verification work is completed.

[0022] The steps of a method for verifying the coordination between generator grid protection and the power grid system are as follows: Step 1: Input the electrical parameters of the generator and transformer in the control console 2 of the electrical simulation system 1, input the protection settings in the generator-transformer group protection device 12, and input the protection settings in the power grid protection device 17.

[0023] Step 2: Run the operating condition simulation. In the control console 2 of the electrical simulation, set the generator no-load, 25%, 50%, 75%, and 100% rated load operating conditions. The signal output module 3 of the electrical simulation system sends the control signal to the signal input module 6 of the power unit. The power unit 5 sends the power signal according to the collected control signal. The power output module 9 of the power transmission unit sends the signal to the terminal 13 of the generator-transformer protection device through the first junction box 11. The power signal then passes through the terminal 15 of the generator-transformer protection device and through the second junction box 16 to the terminal 18 of the grid protection device.

[0024] Step 3: Sample Value Check. In the electrical simulation console 2, start the sample value detection. The power signal received by the power unit's signal input module 6 is sent to the generator-transformer group protection device 12 and the grid protection device 17 via the power unit's power output module 9. Check and record the sample values ​​of the generator-transformer group protection device 12 and the grid protection device 17.

[0025] Step 4: Sampling value error judgment. The output terminal 14 of the generator-transformer protection device and the output terminal 19 of the power grid protection device send their respective protection action information to the signal input module A8 and the signal input module B10 of the power unit, respectively. The power unit 5 sends the collected action signal to the signal input module 4 of the electrical simulation system through the signal output module 7 of the power unit. The action signal sampling value is compared with the power signal issued by the simulation system device 1. Specifically, If the error is greater than 2.0%, proceed to error cause analysis, check the wiring and parameter settings of generator-transformer group protection device 12 and power grid protection device 17, make adjustments, and then repeat the sampling value check in step three.

[0026] If the error is less than or equal to 2.0%, proceed to step five; Step 5: Protection verification. Set the protection type to be verified in the control console 2 of the electrical simulation device. The electrical simulation device 1 sends a power signal according to the set protection type. The generator-transformer group protection device 12 and the power grid protection device 17 start to operate according to the received power signal.

[0027] Step Six: Begin determining the protection coordination relationship. The output terminal 14 of the generator-transformer protection device and the output terminal 19 of the power grid protection device send the action information of the protection device to the signal input module A8 and the signal input module B10 of the power unit, respectively. The power unit 5 sends the received action information to the signal input module 4 of the electrical simulation system through the signal output module 7 of the power unit. The electrical device 1 determines whether the protection meets the coordination relationship based on the received action information and the protection type in Step Five.

[0028] Specifically, When the protection coordination relationship judgment does not meet the logical requirements, the analysis of the cause of protection coordination is initiated. After modifying the protection settings of the generator-transformer group protection device 12 and the power grid protection device 17, the protection verification in step five is performed again. When the protection coordination relationship is determined to meet the logical requirements, the verification of the generator's grid-connected protection and the power grid system coordination is completed.

[0029] Step 7: For different types of generator grid protection and grid protection verification, different protection types are set in the electrical simulation device control console 2. The protection verification in step 5, the protection coordination relationship judgment in step 6, and the protection coordination cause analysis can be carried out in a loop until all protection verifications are completed.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0031] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0032] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0033] The preferred embodiments disclosed above are merely illustrative of this application. The optional embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this application. These embodiments are selected and specifically described in this application to better explain the principles and practical applications of this application, thereby enabling those skilled in the art to better understand and utilize this application.

Claims

1. A system for verifying the coordination between nuclear power plant generator unit protection and grid-connected protection, characterized in that: It includes an electrical simulation device (1), a power unit (5), a first junction box (11), a generator-transformer group protection device (12), a second junction box (16), and a power grid protection device (17). The electrical simulation device (1) includes a control console (2), a signal output module (3), and a signal input module (4) of the electrical simulation system. The power unit (5) includes a power unit signal input module (6), a power unit signal output module (7), a power unit signal input module A (8), a power unit power output module (9), and a power unit signal input module B (10). The generator-transformer protection device (12) includes the wiring terminal (13) of the generator-transformer protection device, the output terminal (14) of the generator-transformer protection device, and the wiring terminal (15) of the generator-transformer protection device. The power grid protection device (17) includes the wiring terminals (18) of the power grid protection device and the output terminals (19) of the power grid protection device. The signal output module (3) is connected to the signal input module (6) of the power unit in the power unit (5), the signal output module (7) of the power unit in the power unit (5) is connected to the signal input module (4) of the electrical simulation system in the electrical simulation device (1), the power output module (9) of the power unit is connected to the first junction box (11), the first junction box (11) is connected to the wiring terminal (13) of the generator-transformer group protection device, the wiring terminal (15) of the generator-transformer group protection device is connected to the second junction box (16), and the second junction box (16) is connected to the wiring terminal (18) of the power grid protection device. The output terminal (14) of the generator-transformer protection device is connected to the signal input module A (8) of the power unit, and the output terminal (19) of the power grid protection device is connected to the signal input module B (10) of the power unit.

2. A method for verifying the coordination between nuclear power plant generator unit protection and grid-connected protection, using the system described in claim 1, characterized in that: Includes the following steps: Step 1: Input the electrical parameters of the generator and transformer in the control console (2) of the electrical simulation system (1), input the protection settings in the generator-transformer group protection device (12), and input the protection settings in the power grid protection device (17); Step 2: Run the operating condition simulation. Set different operating conditions of the generator in the control console (2) of the electrical simulation system. The signal output module (3) of the electrical simulation system sends the control signal to the signal input module (6) of the power unit. The power unit (5) sends the power signal according to the collected control signal. The power output module (9) of the power unit sends the signal to the terminal (13) of the generator-transformer protection device through the first junction box (11). The power signal then passes through the terminal (15) of the generator-transformer protection device and through the second junction box (16) to the terminal (18) of the grid protection device. Step 3: Sample value check. Start sample value detection in the control console (2) of electrical simulation. The power signal received by the signal input module (6) of the power unit is sent to the generator-transformer protection device (12) and the grid protection device (17) through the power output module (9) of the power unit. Check and record the sample values ​​of the generator-transformer protection device (12) and the grid protection device (17). Step 4: Sampling value error judgment. The output terminal (14) of the generator-transformer protection device and the output terminal (19) of the power grid protection device send their respective protection action information to the signal input module A (8) and the signal input module B (10) of the power unit, respectively. The power unit (5) sends the collected action signal to the signal input module (4) of the electrical simulation system through the signal output module (7) of the power unit. The sampled value of the action signal is compared with the power signal issued in the simulation system device (1). If the error is less than or equal to 2.0%, proceed to step 5. Step 5: Protection verification. Set the protection type to be verified in the control console (2) of the electrical simulation device. The electrical simulation device (1) sends a power signal according to the set protection type. The generator-transformer group protection device (12) and the power grid protection device (17) start running according to the received power signal. Step 6: Start the protection coordination relationship judgment. The output terminal (14) of the generator-transformer protection device and the output terminal (19) of the power grid protection device send the action information of the protection device to the signal input module A (8) and the signal input module B (10) of the power unit, respectively. The power unit (5) sends the received action information to the signal input module (4) of the electrical simulation system through the signal output module (7) of the power unit. The electrical device (1) judges whether the protection meets the coordination relationship according to the received action information and the protection type in step 5.

3. The method for verifying the coordination between nuclear power plant generator set protection and grid-connected protection according to claim 2, characterized in that: In step two, the generator is set to run under no-load, 25%, 50%, 75%, and 100% rated load conditions in the electrical simulation control console (2).

4. The method for verifying the coordination between nuclear power plant generator set protection and grid-connected protection according to claim 2, characterized in that: In step four, if the error is greater than 2.0%, proceed to error cause analysis, check the wiring and parameter settings of the generator-transformer protection device (12) and the power grid protection device (17), and after adjustment, re-check the sampling value in step three.

5. The method for verifying the coordination between nuclear power plant generator unit protection and grid-connected protection according to claim 2, characterized in that: In step six, if the protection does not meet the coordination relationship, the protection coordination reason analysis is entered. The protection settings of the generator-transformer group protection device (12) and the power grid protection device (17) are modified and the protection verification in step five is performed again.

6. The method for verifying the coordination between nuclear power plant generator unit protection and grid-connected protection according to claim 2, characterized in that: In step six, if the protections meet the matching requirements, the verification ends.

7. The method for verifying the coordination between nuclear power plant generator set protection and grid-connected protection according to claim 2, characterized in that: In step five, different protection types are set in the electrical simulation device control console (2) for different types of generator grid protection and grid protection verification.

8. The method for verifying the coordination between nuclear power plant generator set protection and grid-connected protection according to claim 2, characterized in that: The protection verification in step five, the determination of protection coordination relationships in step six, and the analysis of the causes of protection coordination are carried out in a loop until all protection verifications are completed.

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