An electromagnetic environment early warning system and an electromagnetic environment early warning method

Abstract

This invention provides an electromagnetic environment early warning system and method. The system includes frequency domain and time domain measurement subsystems and a measurement and control server. The frequency domain measurement subsystem includes a real-time spectrum analyzer, a radio frequency matrix switch, and far-field, near-field, and conducted electromagnetic signal measurement modules, respectively. The outputs of each module are connected to the radio frequency matrix switch, which in turn connects to the real-time spectrum analyzer. The real-time spectrum analyzer performs frequency domain electromagnetic signal measurement and analysis and transmits the data to the measurement and control server. The time domain measurement subsystem includes an oscilloscope and a voltage probe module. The voltage probe module senses and measures the voltage signal fluctuations in the target equipment cables and transmits the data to the oscilloscope. The oscilloscope performs time domain electromagnetic signal measurement and analysis and transmits the data to the measurement and control server. The measurement and control server then issues an alarm. This system can promptly detect electromagnetic risks in the plant area and reduce the risks posed by changes in the electromagnetic environment of a nuclear power plant to the normal operation of equipment.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic environment early warning technology, and in particular to an electromagnetic environment early warning system and an electromagnetic environment early warning method. Background Technology

[0002] The electromagnetic environment faced by instrumentation and control equipment during the operation of a nuclear power plant is extremely complex. The spatial layout of power supplies, equipment, cables, and sensors within the instrumentation and control equipment rooms is complex and varied, with diverse interconnections between devices, and numerous challenges arising from the diverse forms and types of electromagnetic signals. When receiving normal functional signals, the instrumentation and control equipment is affected by various types of signals transmitted or radiated from surrounding equipment, including communication signals, voltage variations, current variations, power variations, the natural electromagnetic environment, and electronic interference. These signals can cause varying degrees of impact on the functionality and performance of the instrumentation and control equipment, leading to functional degradation or malfunction.

[0003] The electromagnetic environment of nuclear power plants is complex and variable, making it difficult to accurately and effectively predict the electromagnetic compatibility (EMC) status throughout the entire lifespan of a nuclear power plant during the design phase. Furthermore, the introduction of advanced equipment and systems during the operational phase, as well as the application of wireless devices, can introduce new electromagnetic interference. Therefore, there is an urgent need to develop a real-time electromagnetic environment measurement system to conduct real-time electromagnetic environment measurement and monitoring of all types of new, under-construction, and in-service nuclear power plants throughout their entire lifespan. This will facilitate the development and establishment of a comprehensive electromagnetic compatibility management or limitation mechanism for nuclear power plants.

[0004] Currently, there is very little research on the electromagnetic environment of nuclear power plants, and there is no comprehensive electromagnetic environment sensing and testing system for nuclear power plants in the industry. For large industrial sites with numerous rooms, complex equipment types, wide spatial distribution, unknown electromagnetic environment risks, and complex and ever-changing types, as well as testing scenarios with numerous types of electromagnetic signals, there is a lack of integrated, multi-parameter, and high-speed comprehensive electromagnetic environment sensing and testing tools. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an electromagnetic environment early warning system and method for comprehensive electromagnetic environment sensing in nuclear power plants. This system can promptly detect electromagnetic risks in the plant area and handle them in a timely manner, thereby significantly reducing the risks to normal equipment operation caused by changes in the electromagnetic environment of nuclear power plants.

[0006] The objective of this invention is achieved through the following technical solution: an electromagnetic environment early warning system, comprising a frequency domain measurement subsystem, a time domain measurement subsystem, and a measurement and control server;

[0007] The frequency domain measurement subsystem includes a real-time spectrum analyzer, a radio frequency matrix switch, a far-field measurement module for measuring far-field electromagnetic signals, a near-field measurement module for measuring near-field electromagnetic signals, and a conducted measurement module for measuring conducted electromagnetic signals. The output terminals of the far-field measurement module, the near-field measurement module, and the conducted measurement module are all connected to the radio frequency matrix switch. The output terminal of the radio frequency matrix switch is connected to the real-time spectrum analyzer. The real-time spectrum analyzer is used to receive the frequency domain electromagnetic signals output by the radio frequency matrix switch, complete the measurement and analysis of the frequency domain electromagnetic signals, and transmit the analysis results of the frequency domain electromagnetic signals to the measurement and control server.

[0008] The time-domain measurement subsystem includes an oscilloscope and a voltage probe module. The voltage probe module is used to sense and measure the fluctuation state of the voltage signal in the cable of the target device and transmit it to the oscilloscope. The oscilloscope performs the measurement and analysis of the time-domain electromagnetic signal and transmits the analysis results of the time-domain electromagnetic signal to the measurement and control server.

[0009] The measurement and control server integrates the measurement and control software platform of the electromagnetic environment early warning system, which is used to receive data transmitted from the real-time spectrum analyzer and oscilloscope, analyze the data, and issue alarm prompts based on the data analysis results and preset alarm mechanisms.

[0010] Furthermore, the measurement and control server is also used to control the operation of various devices in the electromagnetic environment early warning system through the measurement and control software platform, as well as to manage hardware parameters, data storage, alarm mechanism management, and electromagnetic environment management of nuclear power plants in the electromagnetic environment early warning system.

[0011] Furthermore, the far-field measurement module includes multiple far-field measurement units;

[0012] Each far-field measurement unit includes an ultra-wideband planar antenna ranging from 1MHz to 18GHz. The ultra-wideband planar antenna is located on the top of a room in the nuclear power plant, above an entrance or exit, or on the side of a cabinet in the nuclear power plant. It is used to perform spatial electric field measurements in the ultra-wide frequency range of 1MHz to 18GHz and transmit the measurement results to the radio frequency matrix switch.

[0013] Furthermore, the near-field measurement module includes multiple 10kHz to 18GHz ultra-wideband near-field electric field probes and multiple 10kHz to 18GHz ultra-wideband near-field magnetic field probes, and the output terminals of the ultra-wideband near-field electric field probes and the ultra-wideband near-field magnetic field probes are all connected to an RF matrix switch.

[0014] The ultra-wideband near-field electric field probe is installed inside the cabinet of a nuclear power plant and is used to sense and measure electric field signals of 10kHz to 18GHz within a preset distance threshold range for key equipment inside the cabinet of the nuclear power plant.

[0015] The ultra-wideband near-field magnetic field probe is installed inside the cabinet of a nuclear power plant and is used to sense and measure magnetic field signals of 10kHz to 18GHz within a preset distance threshold range for key equipment inside the cabinet of the nuclear power plant.

[0016] The key equipment includes controllers, sensors, actuators, and one or more of cable ports and cable surfaces within the cabinet. An ultra-wideband near-field electric field probe and an ultra-wideband magnetic field electric field probe are installed around each key equipment.

[0017] Furthermore, the conductive measurement module includes multiple current probes, which are open-type current probes used to measure the conducted electromagnetic signals of the target cable to be tested. The output end of the current probe is connected to an RF matrix switch. The target cable to be tested includes one or more of the power lines, signal lines, measurement lines, and control lines of various equipment in a nuclear power plant.

[0018] Furthermore, the radio frequency matrix switch includes an N-to-1 first-level selection switch and N M-to-1 second-level selection switches, where N≥2 and M≥2;

[0019] In this system, each of the N input terminals of the first-stage selection switch is used to connect to a different second-stage selection switch. The output terminal of the first-stage selection switch is connected to the real-time spectrum analyzer and is used to select one signal from the outputs of the N second-stage selection switches to transmit to the real-time spectrum analyzer. For each second-stage selection switch, its M input terminals serve as signal input ports, and the second-stage selection switch is used to select one of the M input signals to transmit to the first-stage selection switch.

[0020] Furthermore, during the process of the real-time spectrum analyzer receiving the signal output from the RF matrix switch, the conduction time of each channel of the RF matrix switch is guaranteed to be greater than the time it takes for the real-time spectrum analyzer to complete one full-band measurement.

[0021] The real-time spectrum analyzer is specifically used to measure and analyze the electromagnetic signals acquired by each front-end probe and antenna of the far-field measurement module, near-field measurement module and conducted measurement module in a cyclical manner according to a set sequence. The measurement bandwidth of the real-time spectrum analyzer is matched with the measurement bandwidth of the front-end probe or antenna, and the analysis results of each measurement and analysis correspond to the input terminal of the RF matrix switch and the front-end probe or antenna respectively.

[0022] Furthermore, the target equipment cables include one or more combinations of power lines, signal lines, measurement lines, and control lines of various devices in the nuclear power plant cabinet, and the voltage signal fluctuation state includes one or more of surge, impulse, pulse group, oscillation wave, and ringing wave;

[0023] The voltage probe module includes multiple alligator clip voltage probes, each of which is clamped and fixed on the cable of a target device under test, and the output end of the voltage probe is connected to the oscilloscope.

[0024] Furthermore, the oscilloscope includes multiple input channels, each corresponding to a voltage probe, used to adjust the test display time and amplitude information based on the signal measured by each voltage probe, and to select the signal triggering mode based on the characteristics of pulse or transient signals, including rising edge triggering and falling edge triggering;

[0025] The oscilloscope is also used to continuously display abnormal signals when the amplitude of the measured pulse signal exceeds a set value;

[0026] The oscilloscope's maximum measurement width and amplitude are matched with the voltage probe, and the measurement bandwidth is greater than the voltage probe's bandwidth. The oscilloscope's maximum input signal amplitude meets the voltage probe's maximum output amplitude requirement, and the signal from the voltage probe is processed according to a set attenuation ratio to ensure the oscilloscope works normally.

[0027] Furthermore, the electromagnetic environment early warning system also includes a test cabinet;

[0028] The measurement and control server, RF matrix switch, real-time spectrum analyzer and oscilloscope are integrated in the test cabinet, and the test cabinet of the early warning system is integrated with an optoelectronic receiving unit containing multiple optoelectronic receiving modules. The number of input ports of the RF matrix switch is the same as the number of optoelectronic receiving modules and they are connected one-to-one.

[0029] The test cabinet is equipped with a direct-connect measurement port that connects to each input terminal of the RF matrix switch for direct input of test signals; the test cabinet is also equipped with a conversion measurement port that connects to each optoelectronic receiving module for converting test signals into optical signals and inputting the obtained optical signals.

[0030] For each detection unit, if the distance between the detection unit and the early warning system test cabinet exceeds the set value, an electro-optical emission module is set in the detection unit. The electro-optical emission module converts the test information of the detection unit into an optical signal, which is then input to the conversion measurement port in the early warning system test cabinet through an optical fiber. After the optical signal enters the photoelectric receiving module through the conversion measurement port, the photoelectric receiving module converts the optical signal into an electrical signal and then transmits it to the input terminal of the corresponding radio frequency matrix switch of the photoelectric receiving module.

[0031] If the distance between the detection unit and the early warning system test cabinet does not exceed the set value, the detection unit is directly connected to the direct connection measurement port of the early warning system test cabinet through the radio frequency cable, and the data is directly transmitted to the input terminal of the radio frequency matrix switch through the direct connection measurement port.

[0032] The detection unit refers to any ultra-wideband planar antenna, current probe, ultra-wideband near-field magnetic field probe, or ultra-wideband near-field electric field probe among the far-field measurement module, near-field measurement module, conduction measurement module, and voltage probe module.

[0033] Secondly, the present invention also provides an electromagnetic environment early warning method, the method comprising:

[0034] The frequency domain measurement subsystem uses a far-field measurement module to measure far-field electromagnetic signals, a near-field measurement module to measure near-field electromagnetic signals, and a conducted measurement module to measure conducted electromagnetic signals. The frequency domain electromagnetic signals measured by the far-field, near-field, and conducted measurement modules are then input to a real-time spectrum analyzer via an RF matrix switch. The real-time spectrum analyzer performs the measurement and analysis of the frequency domain electromagnetic signals and transmits the analysis results to the measurement and control server.

[0035] The voltage probe module in the time-domain measurement subsystem senses and measures the fluctuation of the voltage signal in the cable of the target device. The oscilloscope completes the measurement and analysis of the time-domain electromagnetic signal and transmits the analysis results of the time-domain electromagnetic signal to the measurement and control server.

[0036] The measurement and control software platform, which integrates the electromagnetic environment early warning system, is integrated into the measurement and control server. It receives data transmitted from the real-time spectrum analyzer and oscilloscope, analyzes the data, and issues alarm prompts based on the data analysis results and preset alarm mechanisms.

[0037] The beneficial effects of this invention are:

[0038] (1) This invention addresses the complex electromagnetic environment, dense equipment, and limited space of nuclear power plants. To meet the practical needs of installation in nuclear power plants, an electromagnetic environment early warning system for comprehensive electromagnetic environment sensing is designed. This system is compact, easy to install, and usable during normal operation of the nuclear power plant. It enables real-time, uninterrupted measurement of the power plant's electromagnetic environment, storing the measurement results in a data processing system. Utilizing the statistical and computational functions of this system, the electromagnetic field strength distribution characteristics, time-varying characteristics, and spectral distribution characteristics of the entire power plant in different areas can be statistically summarized within the system.

[0039] (2) This invention has the ability to monitor the electromagnetic environment characteristics parameters in nuclear power plants in real time, collect full-path data in a single cycle, and has the function of electromagnetic interference analysis and location of abnormal signals.

[0040] (3) This invention achieves dynamic acquisition of the electromagnetic environment of the nuclear power plant area by installing electromagnetic signal sensors such as test probes and antennas in key areas of the nuclear power plant. When the electromagnetic environment in the nuclear power plant changes beyond the electromagnetic environment boundary of the normal operation of each equipment, the system can make timely judgments and reminders, ensuring that engineering technicians can promptly discover electromagnetic risks in the plant area and handle them in a timely manner, thereby fully reducing the risks to the normal operation of equipment caused by changes in the electromagnetic environment of the nuclear power plant. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of an electromagnetic environment early warning system provided in Embodiment 1 of the present invention;

[0042] Figure 2 This is an architectural diagram of an electromagnetic environment early warning system provided in Embodiment 1 of the present invention;

[0043] Figure 3 This is a schematic diagram of the radio frequency matrix switch provided in Embodiment 1 of the present invention;

[0044] Figure 4 This is a schematic diagram of the overall structure of the electromagnetic environment early warning system provided in Embodiment 1 of the present invention.

[0045] Figure 5 This is a flowchart illustrating an electromagnetic environment early warning method provided in Embodiment 2 of the present invention. Detailed Implementation

[0046] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments and drawings described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0047] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence; furthermore, in the absence of conflict, the embodiments and features in the embodiments of this invention can be arbitrarily combined with each other.

[0048] The terminology used in the embodiments of this invention is for the purpose of describing particular embodiments only and is not intended to limit this disclosure. The singular forms “a,” “the,” and “the” as used in the embodiments of this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0049] In the following description, the use of suffixes such as "module," "part," or "unit" to denote elements is solely for the purpose of illustrative purposes and has no specific meaning in itself. Therefore, "module," "part," or "unit" may be used interchangeably.

[0050] To ensure that the electromagnetic environment within a nuclear power plant does not negatively impact the operational status of its instrumentation and control equipment during operation, and to maintain its normal functioning, this invention combines the working electromagnetic environment and electromagnetic immunity performance of nuclear power plant instrumentation and control equipment. It comprehensively senses and measures the different electromagnetic characteristics of the equipment at various working locations within the plant, including typical working electromagnetic environments such as electromagnetic frequency, intensity, time domain, frequency domain, and spatial domain. Through long-term monitoring and analysis, it provides the characteristic envelope of the electromagnetic environment of the instrumentation and control equipment rooms. The analysis of the electromagnetic emission and electromagnetic immunity characteristics that nuclear power plant instrumentation and control equipment should possess under different electromagnetic environmental conditions establishes electromagnetic characteristic boundaries, ultimately achieving the adaptability of the instrumentation and control equipment to the complex electromagnetic environment of the plant, and providing a guarantee for the development of electromagnetic compatibility of instrumentation and control equipment.

[0051] This invention relates to a testing tool for comprehensive electromagnetic environment sensing, automatic monitoring, and alarm functions. A series of distributed electromagnetic signal measurement sensors, such as probes and antennas, are flexibly deployed in the target test area. The monitored electromagnetic signals are then transmitted to corresponding signal acquisition and analysis modules through appropriate channels to perform time-domain and frequency-domain electromagnetic signal measurements. Finally, data processing is completed in the measurement and control server. The measurement and control server analyzes and displays the electromagnetic signals, revealing the temporal and spatial variations of the electromagnetic signals in the tested area of ​​the nuclear power plant. Combined with alarm limit judgment conditions for various types of sensors, a visual display and analysis of the electromagnetic environment is achieved. Finally, the measurement results are stored. Specifically:

[0052] like Figure 1 and Figure 2 As shown, Figure 1 This is a schematic diagram of an electromagnetic environment early warning system provided in Embodiment 1 of the present invention. Figure 2 This is an architecture diagram of an electromagnetic environment early warning system, which includes a frequency domain measurement subsystem 1, a time domain measurement subsystem 2, and a measurement and control server 3.

[0053] The frequency domain measurement subsystem 1 includes a real-time spectrum analyzer 11, an RF matrix switch 12, a far-field measurement module 13 for far-field electromagnetic signal measurement, a near-field measurement module 14 for near-field electromagnetic signal measurement, and a conducted measurement module 15 for conducted electromagnetic signal measurement. The output terminals of the far-field measurement module 13, the near-field measurement module 14, and the conducted measurement module 15 are all connected to the RF matrix switch 12. The output terminal of the RF matrix switch 12 is connected to the real-time spectrum analyzer 11. The real-time spectrum analyzer 11 is used to receive the frequency domain electromagnetic signals output by the RF matrix switch 12, complete the measurement and analysis of the frequency domain electromagnetic signals, and transmit the analysis results of the frequency domain electromagnetic signals to the measurement and control server 3.

[0054] The time-domain measurement subsystem 2 includes an oscilloscope 21 and a voltage probe module 22. The voltage probe module 22 is used to sense and measure the fluctuation state of the voltage signal in the target equipment cable and transmit it to the oscilloscope 21. The oscilloscope 21 completes the measurement and analysis of the time-domain electromagnetic signal and transmits the analysis results of the time-domain electromagnetic signal to the measurement and control server 3.

[0055] The measurement and control server 3 integrates the measurement and control software platform of the electromagnetic environment early warning system, which is used to receive data transmitted by the real-time spectrum analyzer 11 and oscilloscope 21, analyze the data, and provide alarm prompts based on the data analysis results and preset alarm mechanisms.

[0056] The measurement and control server 3 is also used to control the operation of various devices in the electromagnetic environment early warning system through the measurement and control software platform, as well as to manage hardware parameters, data storage, alarm mechanism management, and electromagnetic environment management of nuclear power plants in the electromagnetic environment early warning system.

[0057] Electromagnetic environment management adjusts nuclear power plant equipment based on electromagnetic data analysis and alarm status. This includes adjusting equipment by implementing time-segmented operation, relocating fixed equipment installations, dividing or tuning frequencies, reducing equipment transmission power, or replacing equipment with multiple low-power units. These measures reduce the electromagnetic risks associated with the nuclear power plant's electromagnetic environment.

[0058] In an embodiment of the present invention, the measurement and control server 3, the radio frequency matrix switch 12, the real-time spectrum analyzer 11 and the oscilloscope 21 are integrated into a warning system test cabinet (hereinafter referred to as the test cabinet);

[0059] In an embodiment of the present invention, the far-field measurement module 13 includes multiple far-field measurement units; each of the far-field measurement units includes an ultra-wideband planar antenna of 1MHz to 18GHz; the ultra-wideband planar antenna is installed and fixed in the top of the nuclear power plant room, above the entrance / exit, on the side of the nuclear power plant cabinet, or other locations that do not affect the installation of other equipment or the passage of personnel; it is used to complete the spatial electric field measurement in the ultra-wide frequency range of 1MHz to 18GHz and transmit the measurement results to the radio frequency matrix switch 12; in this embodiment, for the ultra-wideband high-sensitivity planar antenna, one antenna can be used to complete the spatial electric field measurement in the ultra-wide frequency range of 1MHz to 18GHz. Electric field measurement not only solves the need for ultra-wideband electromagnetic signal measurement but also saves antenna space, and the placement and installation of planar antennas are very flexible. Since the measurement antenna and the early warning system test cabinet are located in different rooms and are generally far apart, the signal measured by the measurement antenna needs to be transmitted to the measurement port of the early warning system test cabinet through the photoelectric transmission unit. However, for some ultra-wideband planar antennas in far-field measurement units within the set distance (e.g., in rooms relatively close to the early warning test cabinet), they can also be directly connected through RF cables. In the embodiments of this application, the number of high-sensitivity antennas can be flexibly adjusted according to the space electric field testing requirements of nuclear power plants. The nuclear power plant area has very thick reinforced concrete structures between rooms, which greatly obstruct electromagnetic signals. To ensure the integrity of the weak electromagnetic signals collected during transmission and to prevent signal attenuation due to long-distance cable transmission and being drowned out by background noise, thus ensuring signal transmission quality, when the distance exceeds a set value, the electromagnetic signal from the ultra-wideband high-sensitivity planar antenna is converted into an optical signal by a set electro-optical transmission module. This optical signal is then input through an optical fiber to the conversion measurement port in the early warning system test cabinet. After the optical signal enters the photoelectric receiving module through the conversion measurement port, the photoelectric receiving module converts the optical signal into an electrical signal, completing the long-distance qualitative transmission of the early warning system antenna signal. This solves the problem of ultra-wideband electromagnetic signal transmission over tens or even hundreds of meters, ultimately achieving low signal attenuation and complete reproduction of the electromagnetic signal when it reaches the measurement port of the test cabinet. To meet the requirements of long-distance transmission, each antenna requiring long-distance low-loss electromagnetic signal transmission needs to be individually adapted to a photoelectric transmission channel.

[0060] In the embodiments of this application, the near-field measurement module 14 includes multiple 10kHz to 18GHz ultra-wideband near-field electric field probes and multiple 10kHz to 18GHz near-field magnetic field probes; the output terminals of the ultra-wideband near-field electric field probes and the ultra-wideband near-field magnetic field probes are all connected to the radio frequency matrix switch 12.

[0061] The ultra-wideband near-field electric field probe is installed inside the nuclear power plant cabinet to sense and measure electric field signals ranging from 10kHz to 18GHz around critical equipment within the cabinet. It can perform circuit board-level ultra-wideband electric field signal measurements in confined spaces, without spatial limitations. When the near-field probe is close to the test cabinet, the signal can be directly transmitted to the cabinet via an RF cable. When the near-field electric field probe and the early warning system test cabinet are located in different rooms or are far apart, the test signal from the near-field electric field probe can also be transmitted to the measurement port of the early warning system test cabinet via an optoelectronic transmission unit. Furthermore, the number of current probes can be flexibly adjusted according to the near-field electric field testing requirements of the nuclear power plant, and a separate signal transmission channel is configured for each probe.

[0062] The ultra-wideband near-field magnetic field probe is installed inside the nuclear power plant cabinet to measure the magnetic field signals (10kHz–18GHz) around key equipment within the cabinet. When the near-field probe is close to the test cabinet, the signal can be directly transmitted to the cabinet via an RF cable. When the near-field magnetic field probe and the early warning system test cabinet are located in different rooms or are far apart, the test signal can be transmitted to the measurement port of the early warning system test cabinet via an optoelectronic transmission unit. The number of current probes can be flexibly adjusted according to the near-field magnetic field testing requirements of the nuclear power plant, and a separate signal transmission channel is configured for each channel.

[0063] The key equipment includes one or more of the following within the cabinet: controllers, sensors, actuators, cable ports, and cable surfaces. An ultra-wideband near-field electric field probe and an ultra-wideband magnetic field electric field probe are installed around each key device. "Around the key device" refers to a distance from the key device that does not exceed a preset distance threshold. The preset distance threshold can be set according to actual conditions, such as signal strength or ambient noise levels; no restrictions are imposed here.

[0064] In the embodiments of this application, the conducted electromagnetic signal measurement module 15 includes multiple current probes. These probes are open-type and used to measure conducted electromagnetic signals from the target cable to be tested. The output of each current probe is connected to an RF matrix switch 12. The target cable to be tested includes one or more of the power lines, signal lines, measurement lines, and control lines of various equipment in a nuclear power plant. Electromagnetic signal conduction and emission sensing is used, with test frequencies ranging from several kilohertz to several hundred megahertz. When the current probe is close to the test cabinet, the signal can be directly transmitted to the test cabinet via an RF cable. When the current probe and the test cabinet are located in different rooms or are far apart, the test signal from the current probe can be transmitted to the measurement port of the test cabinet via a photoelectric transmission unit. Furthermore, considering the actual conditions of the nuclear power plant, the model and quantity of the current probes are adjusted according to the actual requirements such as test points, cable outer diameter, and test frequency. A signal transmission channel is configured for each channel to achieve flexible arrangement.

[0065] In the embodiments of this application, the radio frequency matrix switch 12 includes an N-to-1 first-level selection switch and N M-to-1 second-level selection switches; N≥2, M≥2, determined according to the number of detection units.

[0066] In this system, each of the N input terminals of the first-stage selection switch is used to connect to a different second-stage selection switch. The output terminal of the first-stage selection switch is connected to the real-time spectrum analyzer 11 and is used to select one signal from the outputs of the N second-stage selection switches to transmit to the real-time spectrum analyzer 11. For each second-stage selection switch, its M input terminals serve as signal input ports. The second-stage selection switch is used to select one of the M input signals to transmit to the first-stage selection switch.

[0067] For the RF matrix switch 12, to meet the requirements of the early warning system for measuring multiple electromagnetic signals, reduce the number of real-time spectrum analyzers 11 in the system, lower the manufacturing cost of the early warning system, and improve testing efficiency by replacing manual switching, the RF matrix switch 12 completes the cyclic switching and transmission of multiple electromagnetic signals according to the measurement control logic sequence of the early warning system, sequentially inputting the electromagnetic signals of the tested channels to the RF input ports of the real-time spectrum analyzer 11. The RF matrix switch 12 of this invention uses a modular multi-input single-output RF switch module. The number of modules is appropriately selected based on the number of electromagnetic signal sensors such as probes and antennas. This embodiment uses seven 6-to-1 modules as an example, where six modules are connected in parallel as first-level modules, and then connected in series with the seventh module, ultimately forming a 36-input, 1-output scheme. Figure 3As shown, the modules are cascaded in series and parallel to achieve large-scale signal input and single-channel output control, enabling rapid selective input and output of RF signals during testing. Finally, the RF electromagnetic signal sensors, including the ultra-wideband high-sensitivity planar antenna, high-sensitivity near-field electric field probe, high-sensitivity near-field magnetic field probe, and current probe, are numbered and connected to the RF input port of the RF matrix switch 12 below. Their outputs are connected to the RF input port of the real-time spectrum analyzer 11.

[0068] In the embodiments of this application, the real-time spectrum analyzer 11 is used to receive the signal output by the radio frequency matrix switch 12 and complete the measurement and analysis of the frequency domain electromagnetic signal; when the radio frequency matrix switch 12 switches, it is ensured that the conduction time of each channel should be at least greater than the time for the real-time spectrum analyzer 11 to complete one full-band measurement; according to the set sequence, the real-time spectrum analyzer 11 cyclically measures and analyzes the electromagnetic signals acquired by each front-end probe and antenna; the measurement bandwidth of the real-time spectrum analyzer 11 is matched with the measurement bandwidth of the front-end probe or antenna, and each measurement data will correspond to the input terminal of the radio frequency matrix switch 12 and the front-end probe or antenna respectively, and finally the test data will be sent to the measurement and control server 3.

[0069] In the embodiments of this application, the target equipment cables tested by the voltage probe include one or more combinations of power lines, signal lines, measurement lines, and control lines of various devices in the nuclear power plant cabinet. The voltage signal fluctuation states include one or more of surge, impulse, pulse group, oscillation wave, and ringing wave; the test frequency ranges from several hertz to hundreds of megahertz. Furthermore, considering the actual conditions of the nuclear power plant, the model and quantity of voltage probes are adjusted according to the actual needs such as test points, test frequencies, and voltage levels, and a signal transmission channel is configured for each channel to achieve flexible deployment.

[0070] The voltage probe module 22 includes multiple alligator clip voltage probes, each of which is clamped and fixed on the cable of a target device to be tested, and the output end of the voltage probe is connected to the oscilloscope 21.

[0071] The oscilloscope 21 includes multiple input channels, each corresponding to a voltage probe. These channels are used to adjust the test display duration and amplitude based on the signals measured by each probe, and to select the signal triggering mode based on pulse or transient signal characteristics. The triggering modes include rising edge triggering and falling edge triggering. When the measured pulse signal amplitude exceeds a set value, the oscilloscope 21 continuously displays the abnormal signal. The maximum measurement width and amplitude of the oscilloscope 21 should match the voltage probe, and the measurement bandwidth should be greater than the voltage probe bandwidth. The maximum input signal amplitude of the oscilloscope should meet the maximum output amplitude requirement of the voltage probe. The signal from the voltage probe is processed according to a set attenuation ratio to ensure the normal operation of the oscilloscope 21 and prevent damage caused by transient pulses. The oscilloscope 21 sends the completed test data to the measurement and control server 3 via a network cable.

[0072] In the embodiments of this application, the early warning system test cabinet integrates an optoelectronic receiving unit containing multiple optoelectronic receiving modules, as well as a display screen, keyboard, mouse, and multiple reserved slots; the electro-optical emitting module adopts an electro-optical converter, and the optoelectronic receiving module adopts an optoelectronic converter; as shown Figure 4 As shown, an electromagnetic environment early warning system for nuclear power plants has been constructed according to this invention. This system enables the separate testing and comprehensive sensing of electromagnetic environment data from nuclear power plants. It measures radiated and conducted electromagnetic signals in multiple scenarios at the nuclear power plant site, analyzes and senses the electromagnetic data, and ultimately extracts electromagnetic elements. This achieves comprehensive sensing of the electromagnetic environment in all areas throughout the entire lifecycle of the nuclear power plant, realizing the goal of separately testing and comprehensively sensing the electromagnetic state characteristics of the nuclear power plant. The electromagnetic data analysis and processing layer should have a human-machine interface interaction function, and data should be automatically collected, recorded, and monitored. It should also enable remote management of sensors, ultimately achieving electromagnetic environment diagnosis and assessment, as well as visualization of electromagnetic environment parameters.

[0073] The electromagnetic environment early warning system of this invention is adaptable to the complex electromagnetic environment, dense equipment, and confined space of nuclear power plants. The system is compact, easy to install, and can be used during normal operation of the nuclear power plant. It can achieve real-time, uninterrupted measurement of the power plant's electromagnetic environment, storing the measurement results in a data processing system. Utilizing the statistical and computational functions of this system, the system can statistically summarize the electromagnetic field strength distribution characteristics, time-varying characteristics, and spectral distribution characteristics of the entire power plant in different areas. Furthermore, it can achieve full-path data acquisition within a single cycle and possesses electromagnetic interference analysis and location capabilities for abnormal signals. When changes in the electromagnetic environment of the nuclear power plant exceed the electromagnetic environment boundaries for normal operation of various equipment, the system can promptly make judgments and issue warnings, ensuring that engineering technicians can promptly detect electromagnetic risks in the plant area and take timely action, effectively reducing the risks posed by changes in the nuclear power plant's electromagnetic environment to the normal operation of equipment.

[0074] Figure 5 This is a schematic diagram of an electromagnetic environment early warning method provided in Embodiment 2 of the present invention, as shown below. Figure 5 As shown, the method includes:

[0075] Step S101: The far-field electromagnetic signal is measured by the far-field measurement module, the near-field electromagnetic signal is measured by the near-field measurement module, and the conducted electromagnetic signal is measured by the conducted measurement module in the frequency domain measurement subsystem. The frequency domain electromagnetic signals measured by the far-field measurement module, the near-field measurement module, and the conducted measurement module are respectively input to the real-time spectrum analyzer through the radio frequency matrix switch. The real-time spectrum analyzer completes the measurement and analysis of the frequency domain electromagnetic signals and transmits the analysis results of the frequency domain electromagnetic signals to the measurement and control server.

[0076] Step S102: The voltage probe module in the time-domain measurement subsystem senses and measures the fluctuation state of the voltage signal in the target equipment cable, the oscilloscope completes the measurement and analysis of the time-domain electromagnetic signal, and the analysis results of the time-domain electromagnetic signal are transmitted to the measurement and control server.

[0077] Step S103: Integrate the electromagnetic environment early warning system's measurement and control software platform into the measurement and control server. Receive data transmitted from the real-time spectrum analyzer and oscilloscope through the measurement and control software platform, analyze the data, and issue alarm prompts based on the data analysis results and preset alarm mechanisms.

[0078] Furthermore, the method also includes:

[0079] The measurement and control software platform controls the operation of various devices in the electromagnetic environment early warning system, as well as manages hardware parameters, data storage, alarm mechanisms, and the electromagnetic environment of nuclear power plants.

[0080] The electromagnetic environment early warning method of this disclosure is applied to the electromagnetic environment early warning system described in any one of Embodiment 1, so the description is relatively simple. For details, please refer to the relevant description in the previous method Embodiment 1, which will not be repeated here.

[0081] The above description represents preferred embodiments of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technical or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. An electromagnetic environment early warning system, characterized by, It includes a frequency domain measurement subsystem, a time domain measurement subsystem, and a measurement and control server; The frequency domain measurement subsystem includes a real-time spectrum analyzer, a radio frequency (RF) matrix switch, a far-field measurement module for measuring far-field electromagnetic signals, a near-field measurement module for measuring near-field electromagnetic signals, and a conducted measurement module for measuring conducted electromagnetic signals. The outputs of the far-field, near-field, and conducted measurement modules are all connected to the RF matrix switch, and the output of the RF matrix switch is connected to the real-time spectrum analyzer. The real-time spectrum analyzer receives the frequency domain electromagnetic signals output by the RF matrix switch, performs measurement and analysis of the frequency domain electromagnetic signals, and transmits the analysis results to the measurement and control server. During the process of receiving frequency domain electromagnetic signals by the real-time spectrum analyzer, when the RF matrix switch is switching, the conduction time of each channel is guaranteed to be greater than the time it takes for the real-time spectrum analyzer to complete one full-band measurement. as well as, During the measurement and analysis of frequency domain electromagnetic signals, the real-time spectrum analyzer is set to perform measurement and analysis on the electromagnetic signals acquired by each front-end probe and antenna of the far-field measurement module, near-field measurement module and conducted measurement module in a set order. The measurement bandwidth of the real-time spectrum analyzer is matched with the measurement bandwidth of the front-end probe or antenna, and the analysis results of each measurement and analysis correspond to the input terminal of the RF matrix switch and the front-end probe or antenna respectively. The time-domain measurement subsystem includes an oscilloscope and a voltage probe module. The voltage probe module is used to sense and measure the fluctuation state of the voltage signal in the cable of the target device and transmit it to the oscilloscope. The oscilloscope performs the measurement and analysis of the time-domain electromagnetic signal and transmits the analysis results of the time-domain electromagnetic signal to the measurement and control server. The measurement and control server integrates the measurement and control software platform of the electromagnetic environment early warning system, which is used to receive data transmitted from the real-time spectrum analyzer and oscilloscope, analyze the data, and issue alarm prompts based on the data analysis results and preset alarm mechanisms.

2. The electromagnetic environment early warning system of claim 1, wherein, The measurement and control server is also used to control the operation of various devices in the electromagnetic environment early warning system through the measurement and control software platform, as well as to manage hardware parameters, data storage, alarm mechanism management, and electromagnetic environment management of nuclear power plants in the electromagnetic environment early warning system.

3. The electromagnetic environment early warning system of claim 1, wherein, The far-field measurement module includes multiple far-field measurement units; Each far-field measurement unit includes an ultra-wideband planar antenna ranging from 1MHz to 18GHz. The ultra-wideband planar antenna is located on the top of a room in the nuclear power plant, above an entrance or exit, or on the side of a cabinet in the nuclear power plant. It is used to perform spatial electric field measurements in the ultra-wide frequency range of 1MHz to 18GHz and transmit the measurement results to the radio frequency matrix switch.

4. The electromagnetic environment early warning system of claim 1, wherein, The near-field measurement module includes multiple 10kHz~18GHz ultra-wideband near-field electric field probes and multiple 10kHz~18GHz ultra-wideband near-field magnetic field probes. The output terminals of the ultra-wideband near-field electric field probes and the ultra-wideband near-field magnetic field probes are all connected to an RF matrix switch. The ultra-wideband near-field electric field probe is installed inside the cabinet of a nuclear power plant and is used to sense and measure electric field signals of 10kHz~18GHz within a preset distance threshold range for key equipment inside the cabinet of the nuclear power plant. The ultra-wideband near-field magnetic field probe is installed inside the cabinet of a nuclear power plant and is used to sense and measure magnetic field signals of 10kHz~18GHz within a preset distance threshold range for key equipment inside the cabinet of a nuclear power plant. The key equipment includes controllers, sensors, actuators, and one or more of cable ports and cable surfaces within the cabinet. An ultra-wideband near-field electric field probe and an ultra-wideband magnetic field electric field probe are installed around each key equipment.

5. The electromagnetic environment early warning system of claim 1, wherein, The conductive measurement module includes multiple current probes, which are open-type current probes used to measure the conducted electromagnetic signals of the target cable to be tested. The output end of the current probe is connected to an RF matrix switch. The target cable to be tested includes one or more of the power lines, signal lines, measurement lines, and control lines of various equipment in a nuclear power plant.

6. The electromagnetic environment early warning system of claim 1, wherein, The radio frequency matrix switch includes an N-to-1 first-stage selection switch and N M-to-1 second-stage selection switches, where N≥2 and M≥2; In this system, each of the N input terminals of the first-stage selection switch is used to connect to a different second-stage selection switch. The output terminal of the first-stage selection switch is connected to the real-time spectrum analyzer and is used to select one signal from the outputs of the N second-stage selection switches to transmit to the real-time spectrum analyzer. For each second-stage selection switch, its M input terminals serve as signal input ports, and the second-stage selection switch is used to select one of the M input signals to transmit to the first-stage selection switch.

7. The electromagnetic environment early warning system of claim 1, wherein, The target equipment cables include one or more combinations of power lines, signal lines, measurement lines, and control lines of various devices in the nuclear power plant cabinet; the voltage signal fluctuation states include one or more of surge, impulse, pulse group, oscillation wave, and ringing wave. The voltage probe module includes multiple alligator clip voltage probes, each of which is clamped and fixed on the cable of a target device under test, and the output end of the voltage probe is connected to the oscilloscope.

8. The electromagnetic environment early warning system of claim 7, wherein, The oscilloscope includes multiple input channels, each corresponding to a voltage probe. It is used to adjust the test display time and amplitude information based on the signal measured by each voltage probe, and to select the signal triggering mode based on the characteristics of pulse or transient signals. The triggering mode includes rising edge triggering and falling edge triggering. The oscilloscope is also used to continuously display abnormal signals when the amplitude of the measured pulse signal exceeds a set value; The oscilloscope's maximum measurement width and amplitude are matched with the voltage probe, and the measurement bandwidth is greater than the voltage probe's bandwidth. The oscilloscope's maximum input signal amplitude meets the voltage probe's maximum output amplitude requirement, and the signal from the voltage probe is processed according to a set attenuation ratio to ensure the oscilloscope works normally.

9. The electromagnetic environment early warning system of any of claims 1-8, wherein, The electromagnetic environment early warning system also includes a test cabinet; The measurement and control server, RF matrix switch, real-time spectrum analyzer and oscilloscope are integrated in the test cabinet, and the test cabinet of the early warning system is integrated with an optoelectronic receiving unit containing multiple optoelectronic receiving modules. The number of input ports of the RF matrix switch is the same as the number of optoelectronic receiving modules and they are connected one-to-one. The test cabinet is equipped with a direct-connect measurement port that connects to each input terminal of the RF matrix switch for direct input of test signals; the test cabinet is also equipped with a conversion measurement port that connects to each optoelectronic receiving module for converting test signals into optical signals and inputting the obtained optical signals. For each detection unit, if the distance between the detection unit and the early warning system test cabinet exceeds the set value, an electro-optical emission module is set in the detection unit. The electro-optical emission module converts the test information of the detection unit into an optical signal, which is then input to the conversion measurement port in the early warning system test cabinet through an optical fiber. After the optical signal enters the photoelectric receiving module through the conversion measurement port, the photoelectric receiving module converts the optical signal into an electrical signal and then transmits it to the input terminal of the corresponding radio frequency matrix switch of the photoelectric receiving module. If the distance between the detection unit and the early warning system test cabinet does not exceed the set value, the detection unit is directly connected to the direct connection measurement port of the early warning system test cabinet through the radio frequency cable, and the data is directly transmitted to the input terminal of the radio frequency matrix switch through the direct connection measurement port. The detection unit refers to any ultra-wideband planar antenna, current probe, ultra-wideband near-field magnetic field probe, or ultra-wideband near-field electric field probe among the far-field measurement module, near-field measurement module, conduction measurement module, and voltage probe module.

10. A method of electromagnetic environment early warning, characterized by, The method includes: The frequency domain measurement subsystem uses a far-field measurement module to measure far-field electromagnetic signals, a near-field measurement module to measure near-field electromagnetic signals, and a conducted measurement module to measure conducted electromagnetic signals. The frequency domain electromagnetic signals measured by the far-field, near-field, and conducted measurement modules are then input to a real-time spectrum analyzer via an RF matrix switch. The real-time spectrum analyzer performs the measurement and analysis of the frequency domain electromagnetic signals and transmits the analysis results to the measurement and control server. During the process of the real-time spectrum analyzer receiving the frequency-domain electromagnetic signal input through the RF matrix switch, when the RF matrix switch is switching, the conduction time of each channel is guaranteed to be greater than the time it takes for the real-time spectrum analyzer to complete one full-band measurement; and... During the frequency domain electromagnetic signal measurement and analysis process of the real-time spectrum analyzer, the real-time spectrum analyzer is set to perform measurement and analysis on the electromagnetic signals acquired by each front-end probe and antenna of the far-field measurement module, near-field measurement module and conducted measurement module in a set order. The measurement bandwidth of the real-time spectrum analyzer is matched with the measurement bandwidth of the front-end probe or antenna, and the analysis results of each measurement and analysis correspond to the input terminal of the RF matrix switch and the front-end probe or antenna respectively. The voltage probe module in the time-domain measurement subsystem senses and measures the fluctuation of the voltage signal in the cable of the target device. The oscilloscope completes the measurement and analysis of the time-domain electromagnetic signal and transmits the analysis results of the time-domain electromagnetic signal to the measurement and control server. The measurement and control software platform, which integrates the electromagnetic environment early warning system, is integrated into the measurement and control server. It receives data transmitted from the real-time spectrum analyzer and oscilloscope, analyzes the data, and issues alarm prompts based on the data analysis results and preset alarm mechanisms.

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