Electromagnetic environment influence assessment method for offshore wind plant

Abstract

The invention provides an offshore wind farm electromagnetic environment influence assessment method, and particularly relates to the field of electromagnetic environment influence analysis, and the method comprises the steps: firstly determining a wind farm center point, setting radiation test points in a preset radius, and obtaining electromagnetic environment test data of each test point through an electromagnetic environment test system; according to the method, electromagnetic interference signals overflowing from a wind power plant in electromagnetic environment test data are sorted out, a maritime electromagnetic wave propagation loss model is utilized to perform deduction calculation, the signal receiving strength of the position where existing equipment is located is obtained, and whether the electromagnetic interference signals have interference influence on the existing equipment or not is comprehensively evaluated by combining the technical standard requirements of the existing equipment. And the electromagnetic environment safety of the offshore wind plant is ensured. According to the method, the technical problem that the electromagnetic environment generated in the operation process of the wind power plant and the influence of the electromagnetic environment on peripheral radio frequency equipment are difficult to effectively test and analyze in the special environment of the offshore wind power plant is solved, so that the position and layout of the offshore wind power plant are reasonably planned according to the evaluation result.

Description

Technical Field

[0001] The present invention relates to the field of electromagnetic environment impact analysis, and in particular to a method for evaluating the electromagnetic environment impact of an offshore wind farm. Background Art

[0002] With the transformation of the global energy structure and the vigorous development of renewable energy, large-scale offshore wind farms, as a key component of clean energy, are expanding in scale. However, during wind farm operation, the impact of electromagnetic environment changes generated by wind turbines and high-voltage transmission lines on surrounding radio frequency equipment is becoming increasingly prominent, becoming a key factor restricting wind farm construction and operation. Traditional electromagnetic environment measurement and analysis technologies mainly focus on the electromagnetic environment of onshore power generation sites and high-voltage transmission lines. However, there is a lack of systematic and in-depth research and effective testing and analysis methods for the electromagnetic environment characteristics of offshore wind farms and their impact on surrounding radio frequency equipment. This problem not only affects the normal operation of wind farms but also potentially interferes with critical facilities such as radio communications and navigation in the surrounding area, posing a safety hazard.

[0003] Existing measurement and analysis technologies have developed a relatively comprehensive system for addressing the electromagnetic environment of onshore power generation sites and high-voltage transmission lines. These technologies utilize measurement equipment to monitor and collect data on electromagnetic radiation in real time, thereby assessing the electromagnetic environment and predicting its potential impact on surrounding radio frequency equipment. These technologies have been widely used in onshore environments, effectively ensuring the compatibility and safety of power and radio communication facilities. However, due to the specific characteristics of offshore wind farm environments, such as the complex ocean climate, the dispersed layout of wind turbine equipment, and the differences in electromagnetic propagation paths, the applicability of existing technologies to offshore wind farms is limited, making it impossible to accurately assess the impact of wind farm operations on surrounding radio frequency equipment.

[0004] In summary, how to develop a technology that can effectively test and analyze the electromagnetic environment generated during the operation of offshore wind farms and its impact on surrounding radio frequency equipment based on the particularity of offshore wind farms is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] The main purpose of the present invention is to provide a method for assessing the electromagnetic environment impact of offshore wind farms, so as to at least solve the technical problem that it is difficult to effectively test and analyze the electromagnetic environment generated during the operation of the wind farm and its impact on surrounding radio frequency equipment under the special environment of the offshore wind farm, so as to reasonably plan the location and layout of the offshore wind farm based on the assessment results.

[0006] In order to achieve the above object, the present invention provides a method for assessing the electromagnetic environment impact of an offshore wind farm.

[0007] In a first aspect, the present invention provides a method for assessing the electromagnetic environmental impact of an offshore wind farm, comprising: Obtaining the center point of the offshore wind farm, and establishing a wind farm radiation test point within a preset radius with the center point of the wind farm as the center; Performing electromagnetic environment testing on the wind farm radiation test point by using an electromagnetic environment testing system to obtain electromagnetic environment testing data, wherein the electromagnetic environment testing data includes: signal frequency and signal power; sorting out electromagnetic interference signals overflowed from wind farms in the electromagnetic environment test data according to the signal frequency and the signal power; Using a marine electromagnetic wave propagation loss model, the electromagnetic interference signal is deduced and calculated to obtain the signal strength received at the location of the existing equipment; Based on the received signal strength and the technical standard requirements of the existing equipment, it is evaluated whether the electromagnetic interference signal causes interference to the existing equipment.

[0008] Optionally, obtaining the center point of the offshore wind farm and establishing a wind farm radiation test point within a preset radius with the center point of the wind farm as the center includes: Obtaining boundary coordinate data and booster station coordinate data of the offshore wind farm, obtaining geometric center point coordinates based on the boundary coordinate data, and determining the geometric center point coordinates and the booster station coordinate data as the wind farm center point; Drawing a plurality of rays radially and evenly spaced along multiple directions with the coordinates of the geometric center point in the center point of the wind farm and the coordinate data of the booster station as centers respectively; Taking the intersection point of each ray and the boundary of the wind farm as the starting point, multiple wind farm radiation test points are planned along the direction of the ray, wherein the wind farm radiation test points include wind farm geometric radiation test points centered on the coordinates of the geometric center point and wind farm booster station radiation test points centered on the booster station coordinate data.

[0009] Optionally, the electromagnetic environment testing system includes: Test antennas for capturing electromagnetic radiation signals from offshore wind farms; A spectrum analyzer connected to the test antenna, the spectrum analyzer being used to analyze the electromagnetic radiation signal to obtain and store the electromagnetic environment test data; A GPS locator is installed within a predetermined range of the spectrum analyzer, and is used to locate the radiation test point of the wind farm.

[0010] Optionally, the selecting, according to the signal frequency and the signal power, electromagnetic interference signals overflowed from the wind farm in the electromagnetic environment test data includes: Obtaining the electromagnetic environment test data of the built wind farm and the electromagnetic environment test data of the planned wind farm; Eliminating, according to the signal frequency, electromagnetic signals overflowing from non-wind farms in the electromagnetic environment test data of the built wind farm and the electromagnetic environment test data of the planned wind farm to obtain suspicious signals generated by the built wind farm; comparing the signal strength of the suspicious signal generated by the existing wind farm with the signal strength of the suspicious signal at the corresponding test point of the proposed wind farm; if the signal strength of the suspicious signal generated by the existing wind farm is greater than the signal strength of the suspicious signal at the corresponding test point of the proposed wind farm, determining the suspicious signal generated by the existing wind farm as a suspicious signal of the existing wind farm; According to the change of the signal strength in the same test direction in the electromagnetic environment test data of the built wind farm, electromagnetic interference signals overflowed from the wind farm in the electromagnetic environment test data are sorted out from the suspicious signals of the built wind farm.

[0011] Optionally, the using of a marine electromagnetic wave propagation loss model to deduce and calculate the electromagnetic interference signal to obtain the signal strength received at the location of the existing equipment includes: Selecting the electromagnetic interference signal of the wind farm radiation test point closest to the boundary of the offshore wind farm as the starting signal; The electromagnetic wave propagation loss model at sea is used to simulate and deduce the electromagnetic wave loss between the starting signal and the location of the established equipment, and the signal strength received at the location of the established equipment is obtained.

[0012] The present application provides an offshore wind farm electromagnetic environment impact assessment method. The method first determines the center point of the offshore wind farm, and uses this as the center to establish multiple radiation test points within a preset radius. Using an advanced electromagnetic environment test system, these test points are subjected to detailed electromagnetic environment tests to obtain electromagnetic environment test data including signal frequency and signal power. By analyzing these data, the electromagnetic interference signals overflowed from the wind farm can be accurately sorted out. The offshore electromagnetic wave propagation loss model is used to deduce and calculate the sorted electromagnetic interference signals, thereby obtaining the signal strength that may be received at the location of the existing equipment. Combined with the technical standards and requirements of the existing equipment, the possible interference impact of the electromagnetic interference signal on the existing equipment is comprehensively evaluated. This method solves the technical problem that it is difficult to effectively test and analyze the electromagnetic environment generated during the operation of the wind farm and its impact on the surrounding radio frequency equipment under the special environment of the offshore wind farm, thereby rationally planning the location and layout of the offshore wind farm based on the assessment results. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings: Figure 1 Schematic diagram of the flow chart of the electromagnetic environmental impact assessment method for offshore wind farms provided in this application.

[0014] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0015] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions in this application will be clearly and completely described below in conjunction with the drawings in this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0016] The terms "first," "second," "third," "fourth," and so forth (if any) in the description and claims of the present invention and in the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or sequential sequence. It should be understood that the terms used in this manner are interchangeable where appropriate, such that the embodiments of the present invention described herein can be practiced in sequences other than those illustrated or described herein.

[0017] In the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described in this application as "exemplary" or "for example" should not be construed as being preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0018] The present application provides a method for assessing the electromagnetic environmental impact of offshore wind farms. The present invention collects electromagnetic environmental data, sorts electromagnetic interference signals, uses an offshore electromagnetic wave propagation model to deduce signal strength, and combines established equipment standards to assess the impact of electromagnetic interference, thereby rationally planning the location and layout of offshore wind farms based on the assessment results.

[0019] The following specific embodiments describe in detail the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0020] Figure 1 The flowchart of the electromagnetic environmental impact assessment method for offshore wind farms provided in this application is intended to provide a detailed description of the electromagnetic environmental impact assessment method for offshore wind farms, such as Figure 1 As shown, the present embodiment provides an offshore wind farm electromagnetic environment impact assessment method, which includes: S101: Acquire a center point of an offshore wind farm, and establish a wind farm radiation test point within a preset radius with the center point of the wind farm as the center.

[0021] Specifically, this step includes: Obtaining boundary coordinate data and booster station coordinate data of the offshore wind farm, obtaining geometric center point coordinates based on the boundary coordinate data, and determining the geometric center point coordinates and the booster station coordinate data as the wind farm center point; Drawing a plurality of rays radially and evenly spaced along multiple directions with the coordinates of the geometric center point in the center point of the wind farm and the coordinate data of the booster station as centers respectively; Taking the intersection point of each ray and the boundary of the wind farm as the starting point, multiple wind farm radiation test points are planned along the direction of the ray, wherein the wind farm radiation test points include wind farm geometric radiation test points centered on the coordinates of the geometric center point and wind farm booster station radiation test points centered on the booster station coordinate data.

[0022] During implementation, this step first determines the wind farm boundary coordinates and the booster station coordinates. Based on the polygonal area enclosed by these boundary coordinates, the geometric center coordinates are calculated. The geometric center coordinates of a polygon can be determined by calculating the polygon's centroid. This involves dividing the polygon into triangles, calculating the centroid of each triangle, and then taking the weighted average of the calculated triangle centroids to determine the polygon's centroid (i.e., the wind farm center).

[0023] The formula for calculating the centroid of a triangle is: Let the coordinates of the three vertices of the triangle be A ( x 1, y 1) B ( x 2, y 2) C ( x 3, y 3), its center of massO ( x , y )'s coordinates are x =( x 1+ x 2+ x 3) / 3, y =( y 1+ y 2+ y 3) / 3.

[0024] If the planning area polygon of the wind farm can be divided into N A triangle, then N The centroid of the triangle is O i ( x i , y i ) ( i=1,2,3…N ); Then the coordinates of the center of the polygon (that is, the coordinates of the geometric center point) are: O ( x , y ) = .

[0025] The coordinate data of the booster station can be directly determined by surveying and mapping, and the coordinates of the geometric center point and the coordinate data of the booster station are determined as the center point of the wind farm; After determining the coordinates of the center point of the wind farm, it is preferred to use the coordinates of the geometric center point of the wind farm O (x, y) as a circle point, the north direction as 0°, and draw rays at intervals of 45° clockwise to obtain 8 rays radiating outward. At the starting point of the intersection of each ray and the boundary of the wind farm, 4 test points are planned along the direction of the ray, and the distance between each test point and the boundary intersection point is 2kM, 10kM, 20kM, and 30kM. 8 rays can plan 32 test points. In the same way, 32 test points are planned with the coordinates of the booster station coordinate data R (x, y) as a circle point.

[0026] It can be understood that planning the wind farm geometric radiation test points centered on the geometric center point coordinates and the wind farm booster station radiation test points centered on the booster station coordinate data can ensure that accurate and comprehensive data can be obtained when evaluating the electromagnetic environment impact of the offshore wind farm.

[0027] S102: Performing an electromagnetic environment test on the wind farm radiation test point using an electromagnetic environment test system to obtain electromagnetic environment test data, where the electromagnetic environment test data includes signal frequency and signal power.

[0028] Specifically, the electromagnetic environment testing system includes: Test antennas for capturing electromagnetic radiation signals from offshore wind farms; A spectrum analyzer connected to the test antenna, the spectrum analyzer being used to analyze the electromagnetic radiation signal to obtain and store the electromagnetic environment test data; A GPS locator is installed within a predetermined range of the spectrum analyzer, and is used to locate the radiation test point of the wind farm.

[0029] The following is a detailed description of the specific implementation process of this step: 1. Composition of electromagnetic environment test system 1. Test antenna: Function: The test antenna is one of the core components of the electromagnetic environment test system, used to capture electromagnetic radiation signals in offshore wind farms.

[0030] Characteristics: The test antenna should have characteristics such as wide bandwidth, high gain, and low noise to ensure that it can accurately capture weak electromagnetic signals in wind farms.

[0031] Installation: The test antenna should be installed above or near the wind farm radiation test point and should point in the direction where electromagnetic interference may occur.

[0032] 2. Spectrum Analyzer: Function: The spectrum analyzer is connected to the test antenna to analyze the captured electromagnetic radiation signal to obtain electromagnetic environment test data (including signal frequency and signal power).

[0033] Characteristics: The spectrum analyzer should have high precision, high resolution, and real-time measurement characteristics to ensure that the frequency and power of electromagnetic signals can be accurately measured and analyzed.

[0034] Operation: During testing, the spectrum analyzer should be set to the appropriate measurement range and resolution to ensure that all electromagnetic signals of interest are captured.

[0035] 3. GPS locator: Function: The GPS locator is installed within the predetermined range of the spectrum analyzer to accurately locate the radiation test point of the wind farm.

[0036] Characteristics: The GPS locator should have high precision, high stability, and be easy to operate to ensure that the geographic location information of each test point can be accurately recorded.

[0037] Operation: Before testing, make sure the GPS locator is properly installed and calibrated, and keep it turned on during the test.

[0038] 4. RF cables Function: RF cables are used to connect test system equipment, including test antennas and spectrum analyzers, to ensure accurate transmission of electromagnetic signals.

[0039] Characteristics: RF cables should have low loss, high shielding, and anti-interference properties to ensure that electromagnetic signals are not interfered with or attenuated during transmission.

[0040] Installation: The RF cables should be properly connected to the test system equipment, and the connections should be tight and not loose.

[0041] 2. Testing Process 1. Preparation before testing: Check whether the test antenna, spectrum analyzer, GPS locator, RF cable and other equipment are intact and functioning properly.

[0042] Set the spectrum analyzer to the appropriate measurement range and resolution, and calibrate the test antenna and spectrum analyzer.

[0043] Turn on the GPS locator and make sure it can receive satellite signals correctly.

[0044] 2. Test point positioning: Determine the location of the wind farm radiation test point based on the wind farm center point and the preset radius range.

[0045] Use a GPS locator to accurately locate each test point and record its geographic location information.

[0046] 3. Electromagnetic environment test: Install the test antenna above or near the test point and ensure its direction is correct.

[0047] Connect the RF cable and connect the test antenna to the spectrum analyzer.

[0048] Start the spectrum analyzer to capture and analyze electromagnetic radiation signals.

[0049] During the test process, the stability and accuracy of the test system should be maintained to avoid external interference and errors.

[0050] 4. Data recording and storage: The spectrum analyzer analyzes the captured electromagnetic signals and displays the electromagnetic environment test data (including signal frequency and signal power).

[0051] These data are recorded and stored in dedicated storage devices for subsequent analysis and processing.

[0052] As can be understood, the above steps clearly demonstrate the composition and testing process of the electromagnetic environment testing system in step S102. The system can accurately capture and analyze electromagnetic radiation signals in offshore wind farms, providing reliable data support for subsequent electromagnetic interference signal sorting, deduction calculation, and evaluation.

[0053] S103: Sorting out electromagnetic interference signals overflowed from wind farms in the electromagnetic environment test data according to the signal frequency and the signal power.

[0054] Specifically, this step includes: Obtaining the electromagnetic environment test data of the built wind farm and the electromagnetic environment test data of the planned wind farm; Based on the signal frequency, electromagnetic signals overflowing from non-wind farms are eliminated from the electromagnetic environment test data of the existing wind farm and the electromagnetic environment test data of the planned wind farm to obtain suspicious signals generated by the existing wind farm; wherein, suspicious signals are used to indicate electromagnetic signals that may be generated by wind farm equipment but have not yet been confirmed. comparing the signal strength of the suspicious signal generated by the existing wind farm with the signal strength of the suspicious signal at the corresponding test point of the proposed wind farm; if the signal strength of the suspicious signal generated by the existing wind farm is greater than the signal strength of the suspicious signal at the corresponding test point of the proposed wind farm, determining the suspicious signal generated by the existing wind farm as a suspicious signal of the existing wind farm; According to the change of the signal strength in the same test direction in the electromagnetic environment test data of the built wind farm, electromagnetic interference signals overflowed from the wind farm in the electromagnetic environment test data are sorted out from the suspicious signals of the built wind farm.

[0055] The following is a detailed description of this step: 1. Obtain electromagnetic environment test data for existing and planned wind farms Data source definition: Existing wind farm electromagnetic environment test data: This data set is an electromagnetic signal dataset collected by a spectrum analyzer from radiation test points (including geometric radiation test points and booster station radiation test points) at an operating offshore wind farm. It contains signal frequency (unit: MHz) and signal power (unit: dBm).

[0056] Proposed wind farm electromagnetic environment test data: Background electromagnetic signal data set collected by a spectrum analyzer from simulated radiation test points within the planned wind farm area (with the same layout as the test points of the existing wind farm), including signal frequency and signal power.

[0057] 2. Eliminate electromagnetic signals from non-wind farm overflows (1) Frequency range screening: Based on the known operating frequency bands of offshore wind farm equipment (for example, the 0.15-30 MHz power frequency harmonic band and the 2.4-5 GHz Wi-Fi band), the electromagnetic environment test data of existing wind farms and planned wind farms are digitally filtered.

[0058] Specific technical means: Filter type: A Butterworth low-pass filter (cutoff frequency 30 MHz) and a Chebyshev high-pass filter (cutoff frequency 0.15 MHz) are combined to form a bandpass filter, retaining signals in the 0.15-30 MHz frequency band.

[0059] Spectrum analysis: For signals in the 2.4-5 GHz frequency band, a fast Fourier transform (FFT) algorithm is used to generate a spectrum diagram and extract signals with main lobe energy exceeding -50 dBm.

[0060] (2) Signal power threshold filtering: Set the background noise threshold (e.g. -70 dBm) for the electromagnetic environment test data of the proposed wind farm, and remove signals with signal power below the threshold in the data of the existing wind farm.

[0061] 3. Suspicious signal strength comparison (1) Data matching rule: The test data of the existing wind farm and the proposed wind farm are matched one by one according to the same radiation test point position (for example, the test point with a test direction of 30° from the geometric center point).

[0062] (2) Calculation of signal strength difference: For the signal power at the same test point, calculate the difference ΔP (unit: dB) between the signal power of the existing wind farm and the signal power of the proposed wind farm.

[0063] Judgment condition: If ΔP > 3 dB (empirical threshold), the signal is judged to be a suspicious signal generated by an existing wind farm.

[0064] 4. Sorting out electromagnetic interference signals overflowing from wind farms (1) Analysis of signal strength change trend: Sliding average method: For the signal power data of multiple test points in the same test direction of the existing wind farm (for example, a 45° direction centered on the booster station), the average value of a sliding window with a length of 5 is calculated according to the time series to generate a smooth curve.

[0065] Standard deviation calculation: Calculate the standard deviation σ of the signal power within the sliding window. If σ < 1 dB (empirical threshold), the signal is judged to be a stable interference source (i.e., overflow signal from wind farm equipment); if σ ≥ 1 dB, it is judged to be random noise or instantaneous interference.

[0066] (2) Interference signal confirmation: Suspicious signals that meet the stability condition (σ < 1 dB) and have a signal strength difference ΔP > 3 dB are marked as electromagnetic interference signals overflowing from the wind farm.

[0067] This step precisely isolates the electromagnetic interference signals generated by wind farm equipment through frequency band screening, power threshold filtering, signal strength difference comparison, and stability analysis, eliminating background noise and other non-target signals (such as ship radar and communication base station signals), ensuring the accuracy of subsequent electromagnetic interference deduction and calculation. Specifically, standardized techniques such as Butterworth filtering, FFT spectrum analysis, sliding average method, and standard deviation calculation are used to achieve objective and quantitative sorting of interference signals, avoiding the subjective errors of manual judgment and providing a reliable data foundation for evaluating the interference impact of wind farms on surrounding radio equipment.

[0068] S104: Using a marine electromagnetic wave propagation loss model, the electromagnetic interference signal is deduced and calculated to obtain the signal strength received at the location of the existing equipment.

[0069] Specifically, this step includes: Selecting the electromagnetic interference signal of the wind farm radiation test point closest to the boundary of the offshore wind farm as the starting signal; The electromagnetic wave propagation loss model at sea is used to simulate and deduce the electromagnetic wave loss between the initial signal and the location of the existing equipment to obtain the signal strength received at the location of the existing equipment. The existing equipment may be equipment such as radar, communication equipment, etc.

[0070] The following is a detailed description of this step: S104.1 Select start signal First, we need to select the electromagnetic interference signal from the wind farm radiation test point closest to the offshore wind farm boundary from the electromagnetic environment test data obtained in the previous step as the starting signal. This step aims to ensure that the selected signal represents the maximum electromagnetic interference that the wind farm may generate externally, because test points near the wind farm boundary are generally more susceptible to electromagnetic activity within the wind farm.

[0071] S104.2 Determine the electromagnetic wave propagation loss model at sea After selecting the starting signal, we need to choose an appropriate marine electromagnetic wave propagation loss model for subsequent deduction and calculation. This model should accurately reflect the propagation characteristics of electromagnetic waves in the marine environment, including phenomena such as attenuation, reflection, and refraction along the propagation path. Common marine electromagnetic wave propagation loss models include empirical models, statistical models, and models based on physical principles. Empirical models, such as the Longley-Rice model, are based on a large amount of experimental data and can consider the impact of various environmental factors on electromagnetic wave propagation. Statistical models, such as the Okumura-Hata model, use statistical analysis to derive a propagation loss prediction formula. Models based on physical principles predict propagation loss based on the laws of physics and the mechanism of electromagnetic wave propagation. The choice of model depends on the specific application scenario and evaluation requirements.

[0072] S104.3 Simulation of Radio Wave Loss Next, we will use the selected marine electromagnetic wave propagation loss model to simulate the starting signal to calculate the electromagnetic wave loss when the starting signal propagates to the location of the existing equipment. This step requires the input of multiple parameters, including the frequency and power of the starting signal, the geometry of the propagation path, the characteristics of the ocean environment (such as seawater depth, salinity, temperature, etc.), and the location information of the existing equipment. Through model calculation, we can obtain the signal strength received at the location of the existing equipment. This strength is the result after taking into account the various losses of electromagnetic waves during the propagation process. The following is the specific calculation process of the simulation and deduction of electromagnetic wave loss: The line-of-sight path transmission loss mainly includes free space transmission loss and oxygen and water vapor absorption loss (corresponding to the 50% time percentage):

[0073] Where: : Line-of-sight path transmission loss, dB; : free space transmission loss, dB; : frequency, GHz; : path length, km; : oxygen absorption attenuation coefficient, dB / km;

[0074] : water vapor absorption attenuation coefficient, dB / km;

[0075] : Water vapor density (g / m3 ), depending on the radioclimatic zone.

[0076] Area A2: ;A1 and B areas: Area C: (For the division of A, B and C areas, please refer to the relevant ITU documents) If the range exceeds the line of sight, that is, the beyond-line-of-sight range, diffraction and scattering losses need to be calculated. Then, the formula for calculating the loss of radio wave long-distance propagation on the sea surface is as follows:

[0077] L s is the free space loss, in dB; L path is the sea surface propagation path loss, in dB; H t is the height of the transmitting antenna, in meters; H r is the height of the receiving antenna, in meters; λ is the signal wavelength, in m; f is the signal frequency, in MHz; d The current distance between the transmitter and receiver, in km; α is the correction factor, with a typical value of 5dB.

[0078] L boat is the hull penetration loss, in dB, The general value is 0dB when the receiving point is on the deck or outdoors without any obstruction. If the receiving point is inside the cabin and is obstructed by glass, the value is 10dB.

[0079] L earth is the diffraction loss caused by the curvature of the earth beyond the horizon, in dB, and its value is as follows: less than the horizon, that is, d ≤ d When it is 0, the value is 0dB; when it is greater than the line of sight, that is, d > d 0, the value is 1.5 ( d - d 0) dB. d is the current distance between the transmitter and receiver (unit: km), d 0 is the sight distance (unit: kM).

[0080] S104.4 Output results Finally, we output the simulation results, namely the received signal strength at the location of the existing equipment. This result will serve as an important basis for evaluating whether the electromagnetic interference signal poses an interference threat to the existing equipment in subsequent steps.

[0081] Through the above steps, we successfully used the marine electromagnetic wave propagation loss model to deduce and calculate the electromagnetic interference signal and obtain the received signal strength at the location of the existing equipment. This step not only provided reliable data support for subsequent interference assessments but also ensured the accuracy and effectiveness of the entire assessment method. Furthermore, by selecting an appropriate model and inputting accurate parameters, we can further improve the accuracy and reliability of the deduction calculations.

[0082] S105: Evaluate whether the electromagnetic interference signal causes interference to the existing equipment based on the received signal strength and the technical standard requirements of the existing equipment.

[0083] The following is a detailed description of this step: S105.1 Collect necessary information First, we need to collect two core pieces of information: one is the electromagnetic interference signal strength received at the location of the existing equipment, calculated in the previous steps; the other is the technical standards and requirements of the existing equipment, which usually include key parameters such as the equipment's tolerance threshold to the electromagnetic environment and the operating frequency range.

[0084] S105.2 Setting evaluation criteria Based on the technical standards and requirements of existing equipment, we establish criteria for assessing the impact of electromagnetic interference. These criteria typically consist of one or more thresholds, used to determine whether the received electromagnetic interference signal strength exceeds the equipment's safe or normal operating range. For example, if the existing equipment's electromagnetic interference tolerance threshold is -100dBm, any signal strength exceeding this threshold may be considered interference.

[0085] S105.3 Conduct interference assessment Next, we compare the strength of the received electromagnetic interference signal with the set evaluation criteria. If the signal strength is below the set threshold, the electromagnetic interference signal is determined to pose no interference risk to existing equipment. If the signal strength is equal to or above the set threshold, we further analyze the degree of match between the signal frequency and the operating frequency of the existing equipment to determine whether there is an actual interference risk.

[0086] During the evaluation process, factors such as the duration and spectrum characteristics of the electromagnetic interference signal also need to be considered, which may affect the severity and consequences of the interference.

[0087] S105.4 Output evaluation results Finally, based on the results of the interference assessment, we produce an assessment report. This report should clearly indicate whether the electromagnetic interference signal poses an interference risk to existing equipment, as well as the extent and potential consequences. If an interference risk does exist, the report should also propose appropriate mitigation measures or recommendations to ensure the normal operation and safety of the existing equipment.

[0088] Through the above steps, we successfully conducted a comprehensive and detailed assessment of whether electromagnetic interference signals pose interference risks to existing equipment, based on received signal strength and the technical standards and requirements of existing equipment. This step not only provides an important scientific basis for the planning and construction of offshore wind farms, but also ensures the safety and reliability of existing equipment in the electromagnetic environment.

[0089] This embodiment provides a method for assessing the electromagnetic environmental impact of an offshore wind farm. The method first determines the center point of the wind farm and establishes radiation test points within a preset radius. Using an electromagnetic environment test system, electromagnetic environment test data from each test point is obtained. The electromagnetic interference signals overflowing from the wind farm are sorted out from the electromagnetic environment test data. An offshore electromagnetic wave propagation loss model is then used to perform deduction and calculation to determine the signal reception strength at the location of existing equipment. Combined with the technical standards and requirements of the existing equipment, a comprehensive assessment is made to determine whether the electromagnetic interference signals pose an interference threat to the existing equipment, thereby ensuring the electromagnetic environmental safety of the offshore wind farm. This method addresses the technical issue of the difficulty in effectively testing and analyzing the electromagnetic environment generated during wind farm operation and its impact on surrounding radio frequency equipment in the special environment of offshore wind farms. This method allows for the rational planning of the location and layout of offshore wind farms based on the assessment results.

[0090] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of the present application and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0091] It should be understood that the present application is not limited to the exact structure described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A method for assessing the electromagnetic environmental impact of an offshore wind farm, characterized in that: include: Obtaining the center point of the offshore wind farm, and establishing a wind farm radiation test point within a preset radius with the center point of the wind farm as the center; Performing electromagnetic environment testing on the wind farm radiation test point by using an electromagnetic environment testing system to obtain electromagnetic environment testing data, wherein the electromagnetic environment testing data includes: signal frequency and signal power; sorting out electromagnetic interference signals overflowed from wind farms in the electromagnetic environment test data according to the signal frequency and the signal power; Using a marine electromagnetic wave propagation loss model, the electromagnetic interference signal is deduced and calculated to obtain the signal strength received at the location of the existing equipment; Based on the received signal strength and the technical standard requirements of the existing equipment, it is evaluated whether the electromagnetic interference signal causes interference to the existing equipment.

2. The method according to claim 1, characterized in that The obtaining of the offshore wind farm center point and establishing a wind farm radiation test point within a preset radius with the wind farm center point as the center include: Obtaining boundary coordinate data and booster station coordinate data of the offshore wind farm, obtaining geometric center point coordinates based on the boundary coordinate data, and determining the geometric center point coordinates and the booster station coordinate data as the wind farm center point; Drawing a plurality of rays radially and evenly spaced along multiple directions with the coordinates of the geometric center point in the center point of the wind farm and the coordinate data of the booster station as centers respectively; Taking the intersection point of each ray and the boundary of the wind farm as the starting point, multiple wind farm radiation test points are planned along the direction of the ray, wherein the wind farm radiation test points include wind farm geometric radiation test points centered on the coordinates of the geometric center point and wind farm booster station radiation test points centered on the booster station coordinate data.

3. The method according to claim 1, characterized in that The electromagnetic environment testing system includes: Test antennas for capturing electromagnetic radiation signals from offshore wind farms; A spectrum analyzer connected to the test antenna, the spectrum analyzer being used to analyze the electromagnetic radiation signal to obtain and store the electromagnetic environment test data; A GPS locator is installed within a predetermined range of the spectrum analyzer, and is used to locate the radiation test point of the wind farm.

4. The method according to claim 1, wherein The step of sorting out electromagnetic interference signals overflowed from wind farms in the electromagnetic environment test data according to the signal frequency and the signal power includes: Obtaining the electromagnetic environment test data of the built wind farm and the electromagnetic environment test data of the planned wind farm; Eliminating, according to the signal frequency, electromagnetic signals overflowing from non-wind farms in the electromagnetic environment test data of the built wind farm and the electromagnetic environment test data of the planned wind farm to obtain suspicious signals generated by the built wind farm; comparing the signal strength of the suspicious signal generated by the existing wind farm with the signal strength of the suspicious signal at the corresponding test point of the proposed wind farm; if the signal strength of the suspicious signal generated by the existing wind farm is greater than the signal strength of the suspicious signal at the corresponding test point of the proposed wind farm, determining the suspicious signal generated by the existing wind farm as a suspicious signal of the existing wind farm; According to the change of the signal strength in the same test direction in the electromagnetic environment test data of the built wind farm, electromagnetic interference signals overflowed from the wind farm in the electromagnetic environment test data are sorted out from the suspicious signals of the built wind farm.

5. The method according to claim 1, wherein The method of using a marine electromagnetic wave propagation loss model to deduce and calculate the electromagnetic interference signal to obtain the signal strength received at the location of the existing equipment includes: Selecting the electromagnetic interference signal of the wind farm radiation test point closest to the boundary of the offshore wind farm as the starting signal; The electromagnetic wave propagation loss model at sea is used to simulate and deduce the electromagnetic wave loss between the starting signal and the location of the established equipment, and the signal strength received at the location of the established equipment is obtained.

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