Nuclear power plant emergency diesel generator grid-connected test device and method

Abstract

The embodiment of the invention provides a grid-connected test device and method for an emergency diesel generator of a nuclear power plant, and belongs to the technical field of nuclear power. The device comprises a power generation system connection module which is connected with an emergency diesel generator and is used for receiving electric energy generated by the emergency diesel generator and detecting a voltage parameter of the emergency diesel generator; the reactive power compensation module is connected with the power generation system connection module and is used for performing reactive power compensation on the electric energy; the power utilization system connection module is connected with the reactive compensation module and the nuclear power plant power utilization system and used for supplying power to the nuclear power plant power utilization system and detecting voltage parameters of the nuclear power plant power utilization system; and the synchronous grid-connected control module is connected with the power generation system connection module and the power utilization system connection module and is used for controlling the connection state of the power generation system connection module and the emergency diesel generator according to the voltage parameters of the emergency diesel generator and the voltage parameters of the power utilization system of the nuclear power plant. The embodiment of the invention can improve the reliability of the grid-connected test of the emergency diesel generator of the nuclear power plant.

Description

Technical Field

[0001] The present application relates to the field of nuclear power technology, and in particular to a test device and method for grid-connected emergency diesel generators in nuclear power plants. Background Art

[0002] The emergency diesel generator of a nuclear power plant is a nuclear safety-grade backup power source. The reliability of the emergency diesel generator of a nuclear power plant is directly related to the safe operation of the nuclear power unit when the external power supply is lost.

[0003] Currently, emergency diesel generators at nuclear power plants are required to undergo regular no-load, low-load, and full-power tests. These tests are performed during routine maintenance using isolated load islanding with LH disks. Full-power tests, however, require grid connection to the nuclear power plant's power system via a mobile load platform during each refueling shutdown. However, existing mobile load platforms exhibit low reliability during full-power tests, impacting the reliability of grid connection tests for emergency diesel generators.

[0004] Therefore, how to improve the reliability of grid connection test of emergency diesel generators in nuclear power plants has become a technical problem that needs to be solved urgently. Summary of the Invention

[0005] The main purpose of the embodiments of the present application is to propose a nuclear power plant emergency diesel generator grid connection test device and method, aiming to improve the reliability of the nuclear power plant emergency diesel generator grid connection test.

[0006] To achieve the above-mentioned purpose, a first aspect of an embodiment of the present application provides a nuclear power plant emergency diesel generator grid connection test device, the device comprising:

[0007] A power generation system connection module, the power generation system connection module is connected to the emergency diesel generator, and is used to receive the electric energy generated by the emergency diesel generator and detect the voltage parameters of the emergency diesel generator;

[0008] a reactive power compensation module, the reactive power compensation module being connected to the power generation system connection module and being configured to perform reactive power compensation on the electric energy generated by the emergency diesel generator according to the voltage parameters of the emergency diesel generator when the power generation system connection module is connected to the emergency diesel generator;

[0009] an electric power system connection module, the electric power system connection module being connected to the reactive power compensation module and the nuclear power plant electric power system, and being used to supply power to the nuclear power plant electric power system based on the electric energy output after reactive power compensation by the reactive power compensation module, and to detect voltage parameters of the nuclear power plant electric power system;

[0010] A synchronous grid-connected control module is connected to the power generation system connection module and the power consumption system connection module, and is used to make grid connection judgments based on the voltage parameters of the emergency diesel generator and the voltage parameters of the nuclear power plant power consumption system, and to control the connection status of the power generation system connection module and the emergency diesel generator.

[0011] In some embodiments, the power generation system connection module includes:

[0012] a first circuit breaker unit, the first circuit breaker unit being used to control a connection state with the emergency diesel generator;

[0013] a first voltage mutual sensing unit, wherein the first current mutual sensing unit is used to detect voltage parameters of the emergency diesel generator;

[0014] The power system connection module includes:

[0015] The second voltage mutual inductance unit is used to detect voltage parameters of the power system of the nuclear power plant.

[0016] In some embodiments, the synchronous grid-connected control module is used to perform grid-connected judgment on the voltage parameters of the emergency diesel generator detected by the first voltage mutual sensing unit and the voltage parameters of the nuclear power plant power system detected by the second voltage mutual sensing unit based on preset grid-connected conditions, and generate a grid-connected control signal;

[0017] When the grid connection control signal indicates that the preset grid connection condition is not met, adjusting the voltage parameters of the emergency diesel generator according to the voltage parameters of the nuclear power plant power system;

[0018] When the grid-connection control signal indicates that the preset grid-connection condition is met, the first circuit breaker unit is controlled to be closed based on the grid-connection control signal, so that the emergency diesel generator is connected to the power generation system connection module.

[0019] In some embodiments, the device further comprises a control and display module; wherein the control and display module comprises: a control unit, a display unit, and a command input unit;

[0020] The instruction input unit is used to obtain input control instructions and send the control instructions to the control unit;

[0021] The control unit is connected to the power system connection module, the power generation system connection module, the reactive compensation module, the synchronous grid-connected control module, the display unit, and the instruction input unit; and is used to generate a control signal according to the control instruction, control the operating status of the power system connection module, the power generation system connection module, the reactive compensation module, and the synchronous grid-connected control module based on the control signal, and display the operating status on the display unit.

[0022] In some embodiments, the control and display module further includes an audible and visual alarm unit, which obtains an alarm signal to control the audible and visual alarm unit to issue an audible and visual alarm, and displays the alarm signal on the display unit; wherein, the alarm signal is generated by the control unit according to the operating status.

[0023] In some embodiments, the power generation system connection module, the reactive power compensation module, and the power consumption system connection module are connected via a single-phase cable;

[0024] The device further comprises: a current compensation module, the current compensation module being arranged in the neutral point of the single-phase cable;

[0025] The alarm signal includes a single-phase grounding fault signal, and the control unit controls the current compensation module to perform current compensation on the capacitive current of the single-phase cable based on the single-phase grounding fault signal.

[0026] To achieve the above-mentioned purpose, a second aspect of the embodiments of the present application provides a method for testing the grid connection of an emergency diesel generator in a nuclear power plant, the method comprising:

[0027] Acquire a voltage parameter of the emergency diesel generator to obtain a first voltage parameter;

[0028] Acquiring a voltage parameter of a power system of a nuclear power plant to obtain a second voltage parameter;

[0029] Performing a synchronous grid connection judgment on the first voltage parameter and the second voltage parameter based on a preset grid connection condition, and generating a grid connection control signal;

[0030] When the grid-connected control signal indicates that the first voltage parameter and the second voltage parameter meet the preset grid-connected condition, the emergency diesel generator is controlled to be connected to the power generation system connection module, and reactive compensation is performed on the electric energy generated by the emergency diesel generator according to the first voltage parameter.

[0031] In some embodiments, after performing grid connection synchronization determination on the first voltage parameter and the second voltage parameter based on the preset grid connection condition and generating a grid connection control signal, the method further includes:

[0032] When the grid-connection control signal indicates that the first voltage parameter and the second voltage parameter do not meet the preset grid-connection condition, performing voltage adjustment on the first voltage parameter based on the second voltage parameter;

[0033] A synchronous grid connection judgment is performed based on the second voltage parameter and the adjusted first voltage parameter. When the adjusted first voltage parameter and the second voltage parameter meet the grid connection conditions, the emergency diesel generator is controlled to be connected to the power generation system connection module.

[0034] To achieve the above-mentioned purpose, the third aspect of an embodiment of the present application proposes an electronic device, which includes a memory and a processor, wherein the memory stores a computer program, and the processor implements the method described in the second aspect when executing the computer program.

[0035] To achieve the above-mentioned purpose, the fourth aspect of the embodiments of the present application proposes a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the method described in the second aspect above.

[0036] The present application proposes a nuclear power plant emergency diesel generator grid-connection test device and method. By connecting the device between the emergency diesel generator and the nuclear power plant's power system, the full-power test of the emergency diesel generator eliminates the need for traditional external resistor / reactance loads. Instead, the device transmits all of its output electrical energy (active and reactive) directly to the plant's existing power supply system, where it is consumed in real time by the plant's normally operating equipment. This method addresses the low reliability of grid-connection tests for nuclear power plants' emergency diesel generators without changing the existing power supply system configuration and layout. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a schematic structural diagram of a grid-connected test device for an emergency diesel generator in a nuclear power plant provided in an embodiment of the present application;

[0038] Figure 2 This is a structural schematic diagram of a grid-connected test device for an emergency diesel generator in a nuclear power plant provided by another embodiment of the present application;

[0039] Figure 3 This is an electrical connection diagram of a nuclear power plant emergency diesel generator grid-connected test device provided in an embodiment of the present application;

[0040] Figure 4 This is a flow chart of a method for testing the grid connection of an emergency diesel generator in a nuclear power plant provided by an embodiment of the present application;

[0041] Figure 5Schematic diagram of the hardware structure of the electronic device provided in the embodiment of the present application;

[0042] Figure numerals: emergency diesel generator 100, nuclear power plant emergency diesel generator grid-connected test device 200, power generation system connection module 210, first circuit breaker unit 211, first voltage mutual inductance unit 212, first current mutual inductance unit 213, first grounding switch 214, first power display unit 215, reactive power compensation module 220, power consumption system connection module 230, second circuit breaker unit 231, second voltage mutual inductance unit 232, second current mutual inductance unit 233, second grounding switch 234, second power display unit 235, synchronous grid-connected control module 240, control display module 250, control unit 251, display unit 252, instruction input unit 253, sound and light alarm unit 254, current compensation module 260, nuclear power plant power consumption system 300. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0044] It should be noted that although the device schematics illustrate functional module divisions and the flowcharts illustrate logical sequences, in certain circumstances, the steps shown or described may be performed in a sequence that differs from the module divisions in the device or the sequence in the flowcharts. The terms "first," "second," and so on, in the specification, claims, and drawings, are used to distinguish similar items and are not necessarily used to describe a specific sequence or precedence.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terms used herein are for the purpose of describing the embodiments of this application only and are not intended to limit this application.

[0046] First, let’s analyze some of the terms used in this application:

[0047] Nuclear power plant emergency diesel generators are safety-grade backup power systems designed specifically for nuclear power plants. When a nuclear power plant loses normal external grid power, they can quickly start and automatically operate, providing emergency power for critical safety facilities such as the reactor cooling system and containment ventilation, ensuring the continued operation of essential safety functions such as core cooling and radioactive material containment. As a crucial component of the defense-in-depth system, nuclear power plant emergency diesel generators must meet stringent nuclear-grade standards (such as RCC-E and IEEE 387), possessing earthquake resistance, high reliability, and regular testing requirements. Their design capacity typically covers all safety-related loads and maintains at least 24 hours of continuous power supply in the event of a plant-wide power outage.

[0048] A static var generator (SVG) is a flexible AC transmission system device based on power electronics technology. It dynamically generates capacitive or inductive reactive current with adjustable magnitude and phase by detecting the grid's reactive power demand in real time. This current is then rapidly injected into the system to compensate for reactive power shortages or surpluses, thereby precisely regulating voltage stability, suppressing voltage fluctuations and flicker, and simultaneously providing harmonic filtering. Compared to traditional static var compensators (SVCs), SVGs offer advantages such as fast response, continuous and smooth regulation, and independence from grid impedance. They are widely used in applications with stringent power quality requirements, such as renewable energy power stations, industrial grids, and nuclear power plants.

[0049] Synchronization and Grid Connection refers to the process of precisely matching the voltage, frequency, and phase angle of the generator output with the corresponding parameters of the power system (or plant power system) and then achieving parallel operation by closing the circuit breaker. Its core purpose is to ensure that the electrical parameters on both sides are highly synchronized at the moment the generator is connected to the grid, avoiding shock current or mechanical torque oscillation caused by asynchrony, thereby ensuring equipment safety and system stability. In nuclear power plants, the synchronization of emergency diesel generators is a critical operation to verify their load capacity and rapid response capabilities. It requires real-time monitoring and parameter adjustment through automatic synchronization devices or manual synchronization meters to ultimately achieve smooth and impact-free grid connection.

[0050] An arc suppression coil is a protective device used in power systems with an ungrounded or resonantly grounded neutral point. By compensating the system's capacitive current to ground by inductive current, it suppresses arcing at the fault point during a single-phase ground fault, preventing arc-induced overvoltage and thus equipment insulation damage and interphase short circuits. Its core principle is to employ overcompensation (the arc suppression coil's inductive current is slightly greater than the system's capacitive current to ground), reducing the residual current at the fault point to below 5A, thus extinguishing the arc and preventing system resonance, ensuring safe grid operation. This device is widely used in nuclear power plants, mining, urban distribution networks, and other applications requiring high power supply reliability.

[0051] Currently, emergency diesel generators in nuclear power plants are required to undergo regular no-load, low-load, and full-power tests. No-load and low-load tests are performed during routine maintenance using an isolated load island with an LH disk. To avoid occupying the overhaul window, full-power tests are conducted during each downtime for refueling, using a mobile load platform connected to the nuclear power plant's power system. However, existing mobile load platforms primarily utilize components such as resistors and reactors, and the high operating power of emergency diesel generators makes them prone to overheating and poor reliability during full-power tests, impacting the reliability of grid-connected tests for emergency diesel generators in nuclear power plants.

[0052] Based on this, the embodiments of the present application provide a nuclear power plant emergency diesel generator grid connection test device and method, aiming to improve the reliability of the nuclear power plant emergency diesel generator grid connection test.

[0053] The nuclear power plant emergency diesel generator grid-connected test device and method provided in the embodiments of the present application are specifically illustrated through the following embodiments. First, the nuclear power plant emergency diesel generator grid-connected test device in the embodiments of the present application is described.

[0054] See also Figure 1 , Figure 1 This is a schematic diagram of the structure of a nuclear power plant emergency diesel generator grid-connected test device 200 provided in an embodiment of the present application. The device includes:

[0055] The power generation system connection module 210 is electrically connected to the emergency diesel generator 100 , and is used to receive the electric energy generated by the emergency diesel generator 100 and detect the voltage parameters of the emergency diesel generator 100 .

[0056] The reactive power compensation module 220 adopts a static reactive power generator. The reactive power compensation module 220 is electrically connected to the power generation system connection module 210. It is used to perform reactive power compensation on the electric energy generated by the emergency diesel generator 100 according to the voltage parameters of the emergency diesel generator 100 when the power generation system connection module 210 is connected to the emergency diesel generator 100. This can prevent the voltage of the nuclear power plant power system 300 from exceeding the operating range due to excessive reactive power, and can improve the voltage stability of the nuclear power plant power system 300 and improve the reliability during the full-power test.

[0057] Specifically, the reactive power compensation module 220 compares the voltage parameter of the emergency diesel generator 100 with the preset voltage parameter. If the voltage parameter of the emergency diesel generator 100 is greater than the preset voltage parameter, it indicates that there is excess reactive power. The reactive power is absorbed by the reactive power compensation module 220 to suppress the voltage rise. If the voltage parameter of the emergency diesel generator 100 is less than the preset voltage parameter, it indicates that there is insufficient reactive power. The reactive power is generated by the reactive power compensation module 220 to support the voltage recovery.

[0058] The power system connection module 230 has one end connected to the reactive power compensation module 220 and is used to receive the electric energy output by the reactive power compensation module 220 after reactive power compensation. The other end of the power system connection module 230 is connected to the nuclear power plant power system 300 and is used to supply power to the nuclear power plant power system 300 based on the electric energy output by the reactive power compensation module 220 after reactive power compensation, and can also detect voltage parameters of the nuclear power plant power system 300.

[0059] The synchronous grid-connected control module 240 is connected to the power generation system connection module 210 and the power consumption system connection module 230, and is used to make grid connection judgments based on the voltage parameters of the emergency diesel generator 100 and the voltage parameters of the nuclear power plant power consumption system 300, and to control the connection status between the power generation system connection module 210 and the emergency diesel generator 100, thereby achieving impact-free and smooth grid connection.

[0060] By connecting the nuclear power plant emergency diesel generator grid-connected test device 200 between the emergency diesel generator 100 and the nuclear power plant power system 300, the full-power test of the emergency diesel generator 100 no longer relies on traditional external resistive / reactive load equipment. Instead, all of its output electrical energy (active and reactive) is directly transmitted to the existing auxiliary power system within the nuclear power plant, where it is consumed in real time by normally operating equipment within the plant, thus completing the test and verification of the emergency diesel generator 100. This solves the problem of low reliability in the grid-connected test of nuclear power plants' emergency diesel generators without changing the existing auxiliary power system configuration and layout.

[0061] See also Figure 2, Figure 2 This is a structural diagram of a nuclear power plant emergency diesel generator grid-connected test device 200 provided in another embodiment of the present application.

[0062] The power generation system connection module 210 includes:

[0063] The first circuit breaker unit 211 is used to control the connection status with the emergency diesel generator 100; wherein, the first circuit breaker is in the open state by default. After the nuclear power plant emergency diesel generator grid-connected test device 200 is connected to the emergency diesel generator 100, it is necessary to control the opening or closing of the first circuit breaker according to the result of the grid-connected judgment of the synchronous grid-connected control module 240.

[0064] The first voltage mutual sensing unit 212 is used to detect the voltage parameters of the emergency diesel generator 100 .

[0065] The first current mutual sensing unit 213 is used to detect the current parameters of the emergency diesel generator 100 .

[0066] The first grounding switch 214 is used to connect the power generation system connection module 210 to the ground to ensure safety.

[0067] The first power display unit 215 is used to indicate whether the power generation system connection module 210 is powered. For example, the first power display unit 215 can be a display light. When the power generation system connection module 210 is powered, the first power display unit 215 is always on; when the power generation system connection module 210 is not powered, the first power display unit 215 is always off. Alternatively, when the power generation system connection module 210 is powered, the first power display unit 215 displays a first color; when the power generation system connection module 210 is not powered, the first power display unit 215 displays a second color.

[0068] The power system connection module 230 includes:

[0069] The second circuit breaker unit 231 is used to control the connection status with the nuclear power plant power system 300; wherein, the second circuit breaker unit 231 is in the open state by default. After the nuclear power plant power system 300 is successfully connected to the power system connection module 230, the second circuit breaker unit 231 will switch from the open state to the closed state.

[0070] The second voltage mutual sensing unit 232 is used to detect voltage parameters of the nuclear power plant power system 300.

[0071] The second current mutual sensing unit 233 is used to detect current parameters of the nuclear power plant power system 300.

[0072] The second grounding switch 234 is used to connect the power system connection module 230 to the ground to ensure safety.

[0073] The second power indicator unit 235 is used to indicate whether the power system connection module 230 is powered. For example, a display light can be used. When the power system connection module 230 is powered, the second power indicator unit 235 is always on; when the power system connection module 230 is not powered, the second power indicator unit 235 is always off. Alternatively, when the power system connection module 230 is powered, the second power indicator unit 235 displays a first color; when the power system connection module 230 is not powered, the second power indicator unit 235 displays a second color.

[0074] In some embodiments, the synchronous grid-connected control module 240 is used to perform grid-connected judgment on the voltage parameters of the emergency diesel generator 100 detected by the first voltage mutual sensing unit 212 and the voltage parameters of the nuclear power plant power system 300 detected by the second voltage mutual sensing unit 232 based on preset grid-connected conditions, and generate a grid-connected control signal.

[0075] The preset grid connection condition is that the voltage parameters of the emergency diesel generator 100 match the voltage parameters of the nuclear power plant power system 300. Specifically, the voltage parameters of the emergency diesel generator 100 include: the voltage, frequency, and phase angle of the emergency diesel generator 100; the voltage parameters of the nuclear power plant power system 300 include: the voltage, frequency, and phase angle of the nuclear power plant power system 300. The preset grid connection condition is that the voltage amplitude difference is within ±5%, the frequency difference is within ±0.5Hz, and the phase angle difference is within ±10°.

[0076] When the voltage amplitude difference between the emergency diesel generator 100 and the nuclear power plant power system 300 is within ±5%, the frequency difference between the emergency diesel generator 100 and the nuclear power plant power system 300 is within ±0.5 Hz, and the phase angle difference between the emergency diesel generator 100 and the nuclear power plant power system 300 is within ±10°, the voltage parameters of the emergency diesel generator 100 and the nuclear power plant power system 300 are determined to be matched, meeting the grid connection conditions. This precise parameter matching and control ensures that the power from the emergency diesel generator 100 can be safely and stably connected to the nuclear power plant power system 300.

[0077] When the grid-connected control signal indicates that the voltage parameters of the emergency diesel generator 100 and the voltage parameters of the nuclear power plant power system 300 do not meet the preset grid-connected conditions, the voltage parameters of the emergency diesel generator 100 are adjusted according to the voltage parameters of the nuclear power plant power system 300 so that the voltage parameters of the emergency diesel generator 100 can match the voltage parameters of the nuclear power plant power system 300.

[0078] For example: if the voltage amplitude difference between the emergency diesel generator 100 and the voltage of the nuclear power plant power system 300 is not within ±5%, the voltage of the emergency diesel generator 100 is adjusted to within ±5% of the voltage of the nuclear power plant power system 300.

[0079] If the frequency difference between the emergency diesel generator 100 and the nuclear power plant power system 300 is not within ±0.5 Hz, the frequency of the emergency diesel generator 100 is adjusted to within ±0.5 Hz of the frequency of the nuclear power plant power system 300 .

[0080] If the phase angle difference between the emergency diesel generator 100 and the nuclear power plant power system 300 is not within ±10°, the phase angle of the emergency diesel generator 100 is adjusted to within ±10° of the phase angle of the nuclear power plant power system 300.

[0081] When the grid-connected control signal indicates that the voltage parameters of the emergency diesel generator 100 and the voltage parameters of the nuclear power plant power system 300 meet the preset grid-connected conditions, the first circuit breaker unit 211 is controlled to close based on the grid-connected control signal to connect the emergency diesel generator 100 with the power generation system connection module 210, thereby supplying power to the nuclear power plant power system 300 through the nuclear power plant emergency diesel generator grid-connected test device 200 provided in the embodiment of the present application, thereby achieving synchronous grid connection and ensuring that the electric energy of the emergency diesel generator 100 can be safely and stably connected to the nuclear power plant power system 300.

[0082] In some embodiments, the nuclear power plant emergency diesel generator grid connection test device 200 further includes a control and display module 250. The control and display module 250 includes: a control unit 251, a display unit 252, a command input unit 253, and an audible and visual alarm unit 254;

[0083] The command input unit 253 is used to receive control commands entered by the nuclear power plant operator and send them to the control unit 251. These control commands include, but are not limited to, synchronization and grid connection control commands, control commands for the reactive power compensation module 220, control commands for the power generation system connection module 210, and control commands for the power consumption system connection module 230. The command input unit 253 can be a keyboard, touch screen, or other human-computer interaction device. The nuclear power plant operator enters the corresponding control commands based on the test requirements.

[0084] The control unit 251 is connected to the power system connection module 230, the power generation system connection module 210, the reactive power compensation module 220, the synchronous grid-connected control module 240, the display unit 252, and the instruction input unit 253. The control unit 251 is configured to generate corresponding control signals according to control instructions, control the operating states of the power system connection module 230, the power generation system connection module 210, the reactive power compensation module 220, and the synchronous grid-connected control module 240 based on the control signals, and display the operating states of the power system connection module 230, the power generation system connection module 210, the reactive power compensation module 220, and the synchronous grid-connected control module 240 on the display unit 252. Furthermore, the control unit 251 generates an alarm signal based on the operating states of the power system connection module 230, the power generation system connection module 210, the reactive power compensation module 220, and the synchronous grid-connected control module 240, controls the sound and light alarm unit 254 to sound and light an alarm based on the alarm signal, and displays the alarm signal on the display unit 252.

[0085] Display unit 252 is used to display the operating status of the power system connection module 230, the power generation system connection module 210, the reactive power compensation module 220, and the synchronous grid connection control module 240, as well as display alarm signals. In addition, display unit 252 can also display relevant safety regulations, test plans, and operating procedures for the grid connection test.

[0086] The sound and light alarm unit 254 is used to generate sound and light alarms according to the alarm signal.

[0087] In some embodiments, the power generation system connection module 210 , the reactive power compensation module 220 , and the power consumption system connection module 230 are connected via a single-phase cable.

[0088] The nuclear power plant emergency diesel generator grid-connected test device 200 also includes a current compensation module 260, which is installed at the neutral point of a single-phase cable and has its other end grounded. The alarm signal includes a single-phase ground fault signal. The control unit 251 controls the current compensation module 260 to compensate for the capacitive current in the single-phase cable based on the single-phase ground fault signal.

[0089] Specifically, the current compensation module 260 is an arc suppression coil, and the design of the arc suppression coil needs to be determined by the length of the single-phase cable. For example: the capacitance C data of a 15kV single-core 500 square millimeter cable is 2.5uF / KM. Assuming that the length L of the single-phase cable from the emergency diesel generator 100 to the nuclear power plant power system 300 is 1KM, the single-phase capacitance C0 is 2.5uF. The capacitive current when a single-phase ground fault signal occurs is I C0 =3U p ωC0(U p is the phase voltage, ω is the angular frequency), the current provided by the arc suppression coil is IL0 , when I L0 =I C0 When the arc suppression coil compensates for this part of the capacitive current, then according to I C0 Design the capacity of the arc suppression coil Q = U p I C0 .

[0090] It should be noted that the current compensation module 260 is always in use when the nuclear power plant emergency diesel generator grid-connected test device 200 is running, and will only exit when the nuclear power plant emergency diesel generator grid-connected test device 200 fails.

[0091] In one embodiment, the current compensation module 260 is disposed between the reactive power compensation module 220 and the power system connection module 230 .

[0092] In some embodiments, the nuclear power plant emergency diesel generator grid-connected test device 200 further includes a power module, which is used to supply power to the control and display module 250 .

[0093] Specifically, the power module includes a battery unit and an AC / DC power interface, wherein the battery unit can store electrical energy to power the control and display module 250. The AC / DC power interface can be connected to the nuclear power plant maintenance power supply to directly power the control and display module 250.

[0094] See also Figure 3 , Figure 3 This is an electrical connection diagram of a nuclear power plant emergency diesel generator grid-connected test device 200 provided in an embodiment of the present application. The nuclear power plant emergency diesel generator grid-connected test device 200 includes:

[0095] The power generation system connection module 210 is electrically connected to the emergency diesel generator 100 and includes a first circuit breaker unit 211, a first current mutual inductance unit 213, a first voltage mutual inductance unit 212, a first grounding switch 214, and a first charge indicator unit 215. The first circuit breaker unit 211 is connected to the emergency diesel generator 100 via a cable, the first current mutual inductance unit 213 is connected to the first circuit breaker unit 211, and the first voltage mutual inductance unit 212, the first grounding switch 214, and the first charge indicator unit 215 are connected to the cable in parallel.

[0096] Reactive power compensation module 220, which uses a static VAR generator and is connected to the power generation system connection module via a cable;

[0097] The current compensation module 260 uses an arc suppression coil and is connected to the reactive power compensation module 220 via a cable;

[0098] The power system connection module 230 has one end connected to the current compensation module 260 and the other end connected to the nuclear power plant power system 300. The power system connection module 230 includes a second disconnecting unit 231, a second current mutual sensing unit 233, a second grounding switch 234, and a second charge display unit 235. The second disconnecting unit 231 is connected to the nuclear power plant power system 300 via a cable; the second current mutual sensing unit 233 is connected to the second disconnecting unit 231, and the second grounding switch 234 and the second charge display unit 235 are connected to the cable in parallel.

[0099] In some embodiments, the nuclear power plant emergency diesel generator grid-connected test device 200 also includes a container structure, which can be a container or other containing structure, capable of accommodating the power generation system connection module 210, the reactive power compensation module 220, the power consumption system connection module 230, the synchronous grid-connected control module 240, the control display module 250 and the power supply module.

[0100] It can be understood that the nuclear power plant emergency diesel generator grid-connected test device 200 provided in the embodiment of the present application is a movable device. If the container structure adopts a container, it can be transported to different facilities of the nuclear power plant by vehicle, so that multiple emergency diesel generators in the nuclear power plant can share a set of nuclear power plant emergency diesel generator grid-connected test device 200, which can save the operating costs of the nuclear power plant.

[0101] In one embodiment, the control logic for performing a full-power grid connection test using the nuclear power plant emergency diesel generator grid connection test device 200 in a nuclear power plant is as follows:

[0102] Step 1: Connect the started emergency diesel generator 100 to the power generation system connection module 210;

[0103] Step 2: Connect the normally operating nuclear power plant power system 300 to the power system connection module 230;

[0104] Step 3: Connect the current compensation module 260 and the reactive power compensation module 220;

[0105] Step 4: Close the second circuit breaker unit 231 in the power system connection module 230;

[0106] Step 5: The synchronous grid connection control module 240 performs a grid connection judgment based on the voltage parameters of the emergency diesel generator 100 detected by the first voltage mutual sensing unit 212 and the voltage parameters of the nuclear power plant power system 300 detected by the second voltage mutual sensing unit 232 based on the preset grid connection conditions, and generates a grid connection control signal.

[0107] Step 5.1: When the grid-connection control signal indicates that the voltage parameters of the emergency diesel generator 100 and the voltage parameters of the nuclear power plant power system 300 meet the preset grid-connection conditions, the first circuit breaker unit 211 in the power generation system connection module 210 is controlled to close based on the grid-connection control signal to connect the emergency diesel generator 100 to the power generation system connection module 210, thereby achieving grid connection;

[0108] Step 5.2: When the grid-connected control signal indicates that the voltage parameters of the emergency diesel generator 100 and the voltage parameters of the nuclear power plant power system 300 do not meet the preset grid-connected conditions, adjust the voltage parameters of the emergency diesel generator 100 according to the voltage parameters of the nuclear power plant power system 300; return to step 4.

[0109] See also Figure 4 , Figure 4 This is an optional flow chart of a method for testing the grid connection of an emergency diesel generator in a nuclear power plant provided in an embodiment of the present application. Figure 4 The method may include but is not limited to steps S401 to S404.

[0110] Step S401, obtaining a voltage parameter of the emergency diesel generator to obtain a first voltage parameter;

[0111] Step S402, obtaining voltage parameters of the nuclear power plant power system to obtain a second voltage parameter;

[0112] Step S403, performing a grid connection judgment on the first voltage parameter and the second voltage parameter based on the preset grid connection condition, and generating a grid connection control signal;

[0113] Step S404, when the grid-connected control signal indicates that the first voltage parameter and the second voltage parameter meet the preset grid-connected conditions, the emergency diesel generator is controlled to be connected to the power generation system connection module, and reactive compensation is performed on the electric energy generated by the emergency diesel generator according to the first voltage parameter.

[0114] In the steps S401 to S404 shown in the embodiment of the present application, by respectively obtaining the voltage parameters of the emergency diesel generator 100 and the nuclear power plant power system 300, the first voltage parameter and the second voltage parameter are obtained, which can accurately grasp the voltage status of the emergency diesel generator 100 and the nuclear power plant power system 300, and provide a reliable basis for subsequent grid connection. Then, based on the preset grid connection conditions, the first voltage parameter and the second voltage parameter are judged to be connected to the grid at the same time, and a grid connection control signal is generated. Finally, when the grid connection conditions are met, the emergency diesel generator 100 is controlled to be connected to the power generation system connection module 210, and the electric energy generated by the emergency diesel generator 100 is reactively compensated according to the first voltage parameter, which can effectively improve the quality of electric energy, reduce voltage fluctuations and power losses, ensure the stable operation of the nuclear power plant power system 300, and improve the reliability of the grid connection test of the nuclear power plant emergency diesel generator 100.

[0115] In step S401 of some embodiments, the voltage parameters of the emergency diesel generator 100 are detected by the first voltage mutual inductance unit 212 in the power generation system connection module 210 to obtain first voltage parameters; wherein the first voltage parameters include the voltage, frequency and phase angle of the emergency diesel generator 100.

[0116] In step S402 of some embodiments, the voltage parameters of the nuclear power plant power system 300 are detected by the second voltage mutual inductance unit 232 in the power system connection module 230 to obtain second voltage parameters; wherein the second voltage parameters include the voltage, frequency and phase angle of the nuclear power plant power system 300.

[0117] In step S403 of some embodiments, the preset grid connection conditions are that the voltage amplitude difference is within ±5%, the frequency difference is within ±0.5 Hz, and the phase angle difference is within ±10°.

[0118] Calculate the voltage difference between the voltage of the emergency diesel generator 100 and the voltage of the nuclear power plant power system 300 to obtain the voltage amplitude difference;

[0119] Calculating the frequency difference between the frequency of the emergency diesel generator 100 and the frequency of the nuclear power plant power system 300 to obtain a frequency difference value;

[0120] Calculate the phase angle of the emergency diesel generator 100 and the phase angle of the nuclear power plant power system 300 to obtain a phase angle difference;

[0121] Grid connection sub-condition 1: The voltage amplitude difference is within ≤±5%;

[0122] Grid connection sub-condition 2: Determine whether the frequency difference is within ±0.5Hz;

[0123] Grid connection sub-condition 3: Determine whether the phase angle difference is within ±10°;

[0124] According to the results of grid connection sub-conditions 1, 2 and 3, a grid connection control signal is obtained.

[0125] When the above three grid-connection sub-conditions are met simultaneously, the grid-connection control signal indicates that the first voltage parameter and the second voltage parameter meet the preset grid-connection condition.

[0126] When at least one of the three grid-connection sub-conditions is not satisfied, the grid-connection control signal indicates that the first voltage parameter and the second voltage parameter do not satisfy the preset grid-connection condition.

[0127] In step S404 of some embodiments, when the grid connection control signal indicates that the first voltage parameter and the second voltage parameter meet the preset grid connection condition, the first circuit breaker 211 in the power generation system connection module 210 is controlled to close, so that the emergency diesel generator 100 is connected to the power generation system connection module 210. At the same time, the reactive power compensation module 220 performs reactive power compensation on the electric energy generated by the emergency diesel generator 100 according to the first voltage parameter.

[0128] Specifically, the reactive power compensation module 220 compares the voltage parameter of the emergency diesel generator 100 with the preset voltage parameter. If the voltage parameter of the emergency diesel generator 100 is greater than the preset voltage parameter, it indicates that there is excess reactive power. The reactive power is absorbed by the reactive power compensation module 220 to suppress the voltage rise. If the voltage parameter of the emergency diesel generator 100 is less than the preset voltage parameter, it indicates that there is insufficient reactive power. The reactive power is generated by the reactive power compensation module 220 to support the voltage recovery.

[0129] In some embodiments, after step S403, the grid connection test method for the nuclear power plant emergency diesel generator may further include but is not limited to:

[0130] When the grid connection control signal indicates that the first voltage parameter and the second voltage parameter do not meet the preset grid connection condition, adjusting the first voltage parameter based on the second voltage parameter;

[0131] The synchronous grid connection judgment is performed based on the second voltage parameter and the adjusted first voltage parameter. When the adjusted first voltage parameter and the second voltage parameter meet the grid connection conditions, the emergency diesel generator 100 is controlled to be connected to the power generation system connection module 210.

[0132] Specifically, when the grid-connected control signal indicates that the first voltage parameter and the second voltage parameter do not meet the preset grid-connected conditions, the first voltage parameter is adjusted based on the second voltage parameter; wherein the first voltage parameter includes the voltage, frequency and phase angle of the emergency diesel generator 100. If any parameter among the voltage, frequency and phase angle cannot meet the corresponding grid-connected sub-condition, the parameter is adjusted accordingly so that the three parameters can meet the corresponding grid-connected sub-condition at the same time.

[0133] A synchronization grid connection judgment is performed again based on the second voltage parameter and the adjusted first voltage parameter. If the adjusted first voltage parameter and the second voltage parameter meet the preset grid connection condition, the first circuit breaker unit 211 in the power generation system connection module 210 is controlled to close, so that the emergency diesel generator 100 is connected to the power generation system connection module 210. At the same time, the reactive power compensation module 220 performs reactive power compensation on the electric energy generated by the emergency diesel generator 100 according to the first voltage parameter.

[0134] The specific implementation of the grid-connected test method for the nuclear power plant emergency diesel generator 100 is substantially the same as the specific embodiment of the grid-connected test device for the nuclear power plant emergency diesel generator 100 described above, and will not be described in detail here.

[0135] The present application also provides an electronic device comprising a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the aforementioned nuclear power plant emergency diesel generator grid connection test method. The electronic device can be any smart terminal, including a tablet computer and an in-vehicle computer.

[0136] See also Figure 5 , Figure 5 The hardware structure of an electronic device according to another embodiment is shown. The electronic device includes:

[0137] The processor 501 may be implemented as a general-purpose CPU (Central Processing Unit), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits, and is used to execute relevant programs to implement the technical solutions provided in the embodiments of the present application.

[0138] The memory 502 can be implemented in the form of a read-only memory (ROM), a static storage device, a dynamic storage device, or a random access memory (RAM). The memory 502 can store an operating system and other application programs. When the technical solutions provided in the embodiments of this specification are implemented through software or firmware, the relevant program codes are stored in the memory 502 and are called by the processor 501 to execute the grid-connected test method for emergency diesel generators in nuclear power plants according to the embodiments of this application.

[0139] Input / output interface 503, used to implement information input and output;

[0140] Communication interface 504, used to implement communication interaction between this device and other devices, which can be achieved through wired means (such as USB, network cable, etc.) or wireless means (such as mobile network, WiFi, Bluetooth, etc.);

[0141] Bus 505 , which transmits information between various components of the device (e.g., processor 501 , memory 502 , input / output interface 503 , and communication interface 504 );

[0142] The processor 501 , the memory 502 , the input / output interface 503 and the communication interface 504 are connected to each other in communication within the device via a bus 505 .

[0143] An embodiment of the present application also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the above-mentioned nuclear power plant emergency diesel generator grid connection test method.

[0144] The memory, as a non-transient computer-readable storage medium, can be used to store non-transient software programs and non-transient computer executable programs. In addition, the memory may include a high-speed random access memory and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory may optionally include a memory remotely arranged relative to the processor, and these remote memories may be connected to the processor via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0145] The embodiments of the present application provide a nuclear power plant emergency diesel generator grid-connection test device and method. By connecting the nuclear power plant emergency diesel generator grid-connection test device between the emergency diesel generator and the nuclear power plant's power system, the full-power test of the emergency diesel generator no longer relies on traditional external resistor / reactance load equipment. Instead, all of the electrical energy (active power + reactive power) output by the generator is directly transmitted to the existing plant power system within the nuclear power plant, where it is consumed in real time by the normally operating equipment within the plant, thereby completing the test verification of the emergency diesel generator. This solves the problem of low reliability in the grid-connection test of nuclear power plant emergency diesel generators without changing the existing plant power system configuration and layout.

[0146] The embodiments described in the embodiments of this application are intended to more clearly illustrate the technical solutions of the embodiments of this application and do not constitute a limitation on the technical solutions provided by the embodiments of this application. Those skilled in the art will appreciate that with the evolution of technology and the emergence of new application scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0147] Those skilled in the art will understand that the technical solutions shown in the figures do not constitute a limitation on the embodiments of the present application, and may include more or fewer steps than shown in the figures, or a combination of certain steps, or different steps.

[0148] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, i.e., they may be located in one place or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of this embodiment.

[0149] Those skilled in the art will appreciate that all or some of the steps in the methods, systems, and functional modules / units in the devices disclosed above may be implemented as software, firmware, hardware, or appropriate combinations thereof.

[0150] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0151] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0152] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the above-mentioned units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0153] The units described above as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0154] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0155] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes multiple instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of various embodiments of the present application. The aforementioned storage medium includes: various media that can store programs, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0156] The non-Company software tools or components appearing in the embodiments of this application are for illustrative purposes only and do not represent actual use.

[0157] The preferred embodiments of the present invention are described above with reference to the accompanying drawings, but are not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and essence of the present invention should be within the scope of the present invention.

Claims

1. A nuclear power plant emergency diesel generator grid connection test device, characterized in that: The device comprises: A power generation system connection module, the power generation system connection module is connected to the emergency diesel generator, and is used to receive the electric energy generated by the emergency diesel generator and detect the voltage parameters of the emergency diesel generator; a reactive power compensation module, the reactive power compensation module being connected to the power generation system connection module and being configured to perform reactive power compensation on the electric energy generated by the emergency diesel generator according to the voltage parameters of the emergency diesel generator when the power generation system connection module is connected to the emergency diesel generator; an electric power system connection module, the electric power system connection module being connected to the reactive power compensation module and the nuclear power plant electric power system, and being used to supply power to the nuclear power plant electric power system based on the electric energy output after reactive power compensation by the reactive power compensation module, and to detect voltage parameters of the nuclear power plant electric power system; A synchronous grid-connected control module is connected to the power generation system connection module and the power consumption system connection module, and is used to make grid connection judgments based on the voltage parameters of the emergency diesel generator and the voltage parameters of the nuclear power plant power consumption system, and to control the connection status of the power generation system connection module and the emergency diesel generator.

2. The nuclear power plant emergency diesel generator grid connection test device according to claim 1, characterized in that: The power generation system connection module includes: a first circuit breaker unit, the first circuit breaker unit being used to control a connection state with the emergency diesel generator; a first voltage mutual sensing unit, wherein the first current mutual sensing unit is used to detect voltage parameters of the emergency diesel generator; The power system connection module includes: The second voltage mutual inductance unit is used to detect voltage parameters of the power system of the nuclear power plant.

3. The nuclear power plant emergency diesel generator grid connection test device according to claim 2, characterized in that: The synchronous grid-connected control module is used to perform grid-connected judgment based on the voltage parameters of the emergency diesel generator detected by the first voltage mutual sensing unit and the voltage parameters of the nuclear power plant power system detected by the second voltage mutual sensing unit based on the preset grid-connected conditions, and generate a grid-connected control signal; When the grid connection control signal indicates that the preset grid connection condition is not met, adjusting the voltage parameters of the emergency diesel generator according to the voltage parameters of the nuclear power plant power system; When the grid-connection control signal indicates that the preset grid-connection condition is met, the first circuit breaker unit is controlled to be closed based on the grid-connection control signal, so that the emergency diesel generator is connected to the power generation system connection module.

4. The nuclear power plant emergency diesel generator grid connection test device according to claim 1, characterized in that: The device further comprises a control and display module; wherein the control and display module comprises: a control unit, a display unit, and an instruction input unit; The instruction input unit is used to obtain input control instructions and send the control instructions to the control unit; The control unit is connected to the power system connection module, the power generation system connection module, the reactive compensation module, the synchronous grid-connected control module, the display unit, and the instruction input unit; and is used to generate a control signal according to the control instruction, control the operating status of the power system connection module, the power generation system connection module, the reactive compensation module, and the synchronous grid-connected control module based on the control signal, and display the operating status on the display unit.

5. The nuclear power plant emergency diesel generator grid connection test device according to claim 4, characterized in that: The control and display module also includes an audible and visual alarm unit, which obtains an alarm signal to control the audible and visual alarm unit to issue an audible and visual alarm, and displays the alarm signal on the display unit; wherein, the alarm signal is generated by the control unit according to the operating status.

6. The nuclear power plant emergency diesel generator grid connection test device according to claim 5, characterized in that: The power generation system connection module, the reactive power compensation module, and the power consumption system connection module are connected via a single-phase cable; The device further comprises: a current compensation module, the current compensation module being arranged in the neutral point of the single-phase cable; The alarm signal includes a single-phase grounding fault signal, and the control unit controls the current compensation module to perform current compensation on the capacitive current of the single-phase cable based on the single-phase grounding fault signal.

7. A test method for grid connection of emergency diesel generators in nuclear power plants, characterized in that: The method comprises: Acquire a voltage parameter of the emergency diesel generator to obtain a first voltage parameter; Acquiring a voltage parameter of a power system of a nuclear power plant to obtain a second voltage parameter; Performing a synchronous grid connection judgment on the first voltage parameter and the second voltage parameter based on a preset grid connection condition, and generating a grid connection control signal; When the grid-connected control signal indicates that the first voltage parameter and the second voltage parameter meet the preset grid-connected condition, the emergency diesel generator is controlled to be connected to the power generation system connection module, and reactive compensation is performed on the electric energy generated by the emergency diesel generator according to the first voltage parameter.

8. The method according to claim 7, characterized in that After performing synchronous grid connection judgment on the first voltage parameter and the second voltage parameter based on the preset grid connection condition and generating a grid connection control signal, the method further includes: When the grid-connection control signal indicates that the first voltage parameter and the second voltage parameter do not meet the preset grid-connection condition, performing voltage adjustment on the first voltage parameter based on the second voltage parameter; A synchronous grid connection judgment is performed based on the second voltage parameter and the adjusted first voltage parameter. When the adjusted first voltage parameter and the second voltage parameter meet the grid connection conditions, the emergency diesel generator is controlled to be connected to the power generation system connection module.

9. An electronic device, characterized in that: The electronic device includes a memory and a processor, the memory stores a computer program, and the processor implements the method according to any one of claims 7 to 8 when executing the computer program.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 7 to 8 is implemented.

Images