A high-frequency signal acquisition system and method for grounding resistance of a grounding system

Abstract

The application discloses a grounding resistance high-frequency signal acquisition system and method for a grounding system, and relates to the technical field of grounding monitoring. The system comprises a signal transmitting unit, a signal transmitting unit, a signal receiving unit, an adaptive fixing mechanism and a control and power supply unit. The signal transmitting unit dynamically adjusts the beam curvature based on a neural network, so that the high-frequency excitation signal is transmitted along a curved trajectory to bypass the obstruction. The signal transmitting unit adopts a cooperative transmission architecture combining wired transmission, rotating slip ring adaptation and wireless blind filling. The signal receiving unit extracts the effective characteristic parameters required for grounding resistance inversion from the collected signals. The application can adaptively configure the excitation frequency, transmission mode and beam parameters according to the soil resistivity and environmental obstruction information. The application can realize non-intrusive grounding resistance acquisition without disassembly, effectively improve the signal transmission success rate in complex terrain non-line-of-sight scenes and the measurement accuracy in strong electromagnetic environments.

Description

Technical Field

[0001] This invention relates to the field of grounding monitoring technology, specifically to a high-frequency signal acquisition system and method for grounding resistance in grounding systems. Background Technology

[0002] The grounding system of transmission line towers and communication base station towers is a core protective facility for the safe and stable operation of power and communication equipment. It mainly undertakes the function of rapid discharge of lightning current and equipment fault current. The grounding resistance is a core technical parameter that directly measures the current conduction and lightning protection performance of the grounding system. Its value directly determines the discharge efficiency of fault current and lightning current, and plays a decisive role in the operational safety and reliability of power and communication networks.

[0003] Currently, the industry has clear testing standards and limit requirements for the grounding resistance of iron towers. The grounding resistance of iron towers must be subject to periodic full-scale testing, with a testing cycle of once every four years. Routine and accurate grounding resistance testing is a key means to ensure that the grounding system of iron towers continuously meets the standards and to avoid safety accidents such as lightning damage and equipment failure.

[0004] Currently, the mainstream methods for measuring grounding resistance in the industry are the traditional three-electrode and four-electrode methods. In actual testing operations, these methods require manually disconnecting the grounding down conductor of the tower and setting up dedicated test electrodes on-site. The overall process is cumbersome, labor-intensive, time-consuming, and extremely inefficient. More importantly, disconnecting the grounding down conductor during testing directly damages the structural integrity of the grounding system, causing the tower to completely lose its grounding protection capability during the testing period, posing a significant temporary operational safety hazard. Furthermore, this type of offline measurement method can only achieve fixed-point, timed sampling testing, and cannot meet the needs of real-time, dynamic monitoring of grounding resistance under long-term tower operation. It is difficult to detect hidden faults such as aging, corrosion, and grounding failure in the grounding system in a timely manner, resulting in serious deficiencies in the timeliness and comprehensiveness of maintenance.

[0005] In response to the many drawbacks of traditional measurement technologies, non-invasive, wire-free, and online grounding resistance measurement technology has become a key research and development focus in the field of power communication operation and maintenance.

[0006] The non-removable grounding lead measurement method directly collects the operating current at the tower feet by using a current sensor, and can complete the measurement without removing the grounding lead. This avoids the problem of the traditional technology damaging the integrity of the grounding system. However, this technology is highly dependent on the matching arrangement of specific test electrodes, has poor on-site deployment flexibility, and the collected current signal is easily interfered with in the strong electromagnetic environment of the transmission line, resulting in weak measurement signal stability, which directly affects the measurement accuracy of grounding resistance.

[0007] Reference 1: Chinese patent application with publication number CN207780117U.

[0008] Reference 1 discloses a hardware architecture that includes a control module, a measurement module, a current sensor, and an auxiliary grounding electrode, which can complete the measurement operation without removing the grounding lead; it accurately collects the tower foot current signal through the current sensor, performs data calculation based on the measurement module, and finally realizes the grounding resistance calculation; at the same time, it eliminates the traditional voltage test circuit, effectively avoiding the signal interference problem between multiple circuits.

[0009] However, it uses conventional conductors to complete signal transmission and does not have a dedicated electromagnetic shielding structure designed for the strong electromagnetic interference environment of power transmission lines. In the complex electromagnetic environment of high-voltage power transmission scenarios, the collected measurement signals are prone to distortion and drift, resulting in large errors in the grounding resistance measurement results. The measurement stability and accuracy cannot meet the high-standard operation and maintenance requirements.

[0010] Electromagnetic coupling non-contact measurement technology abandons the contact-based signal acquisition mode. It injects an excitation signal into the grounding system through a transmitting coil, and then a receiving coil acquires the electromagnetic induction response signal. Based on the principle of electromagnetic coupling, it achieves completely non-invasive measurement, thoroughly eliminating the drawbacks of wire disconnection. However, the high-frequency excitation signal used in this technology propagates in a straight beam. In complex terrains such as mountainous and forested areas, it is easily blocked and attenuated by obstacles such as trees, mountains, and buildings, leading to signal transmission interruption, missing response signals, and inability to complete effective measurements. Its environmental adaptability is extremely poor.

[0011] Reference 2: Chinese patent application with publication number CN121385433A.

[0012] Reference 2 discloses a contactless measurement method for the grounding resistance of transmission towers based on the principle of electromagnetic coupling. It employs a wideband high-frequency AC excitation signal of 10kHz-1MHz and relies on the electromagnetic coupling effect between the transmitting and receiving coils to achieve contactless measurement of the tower's grounding resistance, effectively improving the convenience of measurement. However, this technology only discloses the core principle of high-frequency electromagnetic coupling measurement and does not design a corresponding stable high-frequency signal transmission scheme for complex field conditions of the towers. It fails to address the core problem that high-frequency straight beam signals are easily blocked and attenuated by terrain obstacles, resulting in insufficient measurement reliability in complex terrain scenarios and limited applicability of the technology.

[0013] The Internet of Things (IoT) online monitoring method combines IoT and remote data transmission technologies to achieve remote acquisition and real-time monitoring of tower grounding resistance data, overcoming the timeliness limitations of traditional offline measurements. However, in practical applications, stable high-frequency signal transmission between rotating components such as tower antenna supports and fixed equipment units is difficult to achieve. Existing equipment generally uses ordinary slip rings for signal switching, which cannot meet the stable transmission requirements of high-frequency excitation signals and is difficult to adapt to the technical requirements of high-precision online monitoring. Summary of the Invention

[0014] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-frequency signal acquisition system and method for grounding resistance in grounding systems.

[0015] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a high-frequency signal acquisition system for grounding resistance of a grounding system, comprising a signal transmitting unit, a signal receiving unit, an adapter fixing mechanism, and a control and power supply unit.

[0016] The signal transmitting unit includes an excitation signal generation module, a beamforming module, and a power amplification module. The excitation signal generation module is used to generate a frequency-adjustable high-frequency excitation signal, the beamforming module is used to adjust the beam curvature so that the high-frequency signal is transmitted along a curved trajectory, and the power amplification module is used to amplify the power of the high-frequency signal.

[0017] The excitation signal generation module uses a frequency-adjustable high-frequency signal generator with an output frequency range of 10kHz-5MHz. It supports two excitation modes: sine wave and frequency modulation signal. The signal amplitude can be adaptively adjusted by the control module.

[0018] The beamforming module integrates an Airy beam generator and dynamically adjusts the beam curvature (curvature range 0.01-0.1 rad / m) based on a neural network algorithm, so that high-frequency signals propagate along a curved trajectory, bypassing obstructions such as towers, trees, and terrain obstacles.

[0019] The signal transmission unit includes a wired transmission module, a rotation adapter module, and a wireless blind spot filling module; the wired transmission module is used to transmit signals through a shielded cable, the rotation adapter module is used to maintain continuous signal transmission at rotating parts, and the wireless blind spot filling module is used to provide a wireless transmission link when wired transmission cannot be deployed. The signal receiving unit includes a signal acquisition module, a signal processing module, and a data storage module; the signal acquisition module is used to acquire received signals, the signal processing module is used to filter and decouple the received signals and extract effective feature parameters, and the data storage module is used to locally cache measurement data. The adapter fixing mechanism includes a tower mounting assembly and a grounding electrode fixing assembly. The tower mounting assembly is used to mount the receiving unit on the tower, and the grounding electrode fixing assembly is used to fix the transmitting unit near the grounding electrode and electrically isolate the transmitting unit from the grounding electrode. The tower mounting components adopt an adjustable clamp structure, with anti-slip rubber pads on the inside of the clamps, and the surface is hot-dip galvanized. The grounding electrode fixing assembly adopts a magnetic or bolt-type fixing base, which can be directly attached to the grounding flat steel of the tower foot or the surface of the grounding electrode. The fixing base has an internal insulating pad to avoid direct conductive contact with the grounding electrode.

[0020] The control and power supply unit includes a control module and a power supply module; the control module is used to configure the excitation signal frequency, beam curvature and transmission mode, and to communicate with the outside, while the power supply module is used to supply power to the entire acquisition system.

[0021] The control module uses an STM32H7 series microcontroller, which integrates Bluetooth and 4G / 5G communication interfaces. It supports local parameter configuration (via Bluetooth) and remote data transmission (via 4G / 5G) and can be connected to a smart grid operation and maintenance platform.

[0022] The power supply module supports both solar power and lithium battery backup power, and features overcharge, over-discharge, and short-circuit protection.

[0023] The beamforming module has a neural network inference unit, which is used to output the target beam curvature based on environmental perception information and received signal quality information, thereby realizing dynamic adjustment of the beam curvature.

[0024] The neural network inference unit can be any of a multilayer perceptron, a convolutional neural network, or a deep reinforcement learning network, and is deployed on a microcontroller or a dedicated neural network processor.

[0025] The present invention also provides a method for high-frequency signal acquisition of grounding resistance in a grounding system. Based on the above system, the method includes the following steps: S1. The transmitting unit is fixed near the grounding body by an adapter fixing mechanism, and the receiving unit is mounted on the middle of the tower or at the foot of the tower. S2. Determine the excitation signal frequency based on soil resistivity information, select the signal transmission mode based on environmental occlusion information, and output the target beam curvature based on neural network in wireless blind spot transmission mode. S3. After the receiving unit acquires the high-frequency excitation signal generated by the transmitting unit, it performs filtering and decoupling processing, extracts effective feature parameters, and transmits the effective feature parameters to the back-end measurement system for grounding resistance inversion calculation.

[0026] As a further optimization of the high-frequency signal acquisition method for grounding resistance in a grounding system according to the present invention, step S2 specifically includes: S21. Obtain soil resistivity information and environmental shading information around the tower; S22. Determine the excitation signal frequency from the preset correspondence based on the soil resistivity information; S23. Select the signal transmission mode based on environmental obstruction information; The signal transmission mode is selected based on the relative distance between the obstacle and the transmitting unit, the azimuth angle of the obstacle relative to the transmitting unit, or the size of the obstacle: When there is a direct line of sight between the transmitting unit and the receiving unit and wiring is possible, select the wired transmission mode; When the signal path passes through the tower's rotating components, select wired transmission mode and enable rotational adaptation transmission mode; When there are obstructions and wired transmission links cannot be deployed, select the wireless blind spot filling transmission mode.

[0027] When the selected signal transmission mode is wireless blind spot filling transmission mode, the environmental occlusion information is input into the pre-trained neural network model, and the neural network model outputs the target beam curvature. The neural network model can be any one of a multilayer perceptron, a convolutional neural network, or a deep reinforcement learning network, and the target beam curvature ranges from 0.01 to 0.1 rad / m.

[0028] S24. Configure signal transmission according to the determined excitation signal frequency and signal transmission mode; In the wireless blind spot transmission mode, the phase modulation parameters of the Airy beam generator are adjusted according to the curvature of the target beam so that the high-frequency excitation signal is transmitted in a curved trajectory corresponding to the curvature of the target beam. Airy beam generator according to phase distribution

[0029] Phase modulation is performed, where λ is the signal wavelength and R0 is the wavefront curvature radius.

[0030] S25. Input the current environmental perception information, the current beam curvature and the latest received signal quality information into the neural network model to obtain the updated target beam curvature. The received signal quality information includes at least one of received signal strength indication, signal-to-noise ratio and bit error rate. If the difference between the updated target beam curvature and the current beam curvature is less than a set threshold, or if the received signal quality meets preset conditions, the update will stop.

[0031] Specifically: The receiving unit measures the received signal quality (such as RSSI, SNR, and bit error rate) in real time and feeds it back to the transmitting unit control module via the backhaul link. When the received signal quality falls below a preset threshold, the system triggers the following update process: The current environmental occlusion information and the received signal quality information are jointly input into the neural network model (at this time, the network input adds signal quality features on the basis of environmental features). The network outputs the updated target curvature κ t ; If |κ t -κ c If | < 0.002 rad / m, or if the received signal quality meets the requirements, then stop updating; Otherwise, adjust the beam curvature to κ. t That is, let κ c=κ t Continue to monitor signal quality.

[0032] The present invention has the following beneficial effects: By integrating Airy beamforming and neural network to dynamically adjust beam curvature, the present invention enables high-frequency signals to bypass obstacles along a curved trajectory, solving the signal obstruction problem in complex terrain and significantly improving the transmission success rate under non-line-of-sight conditions. Attached Figure Description

[0033] Figure 1 Structural block diagram of the high-frequency signal acquisition system for grounding resistance of this invention; Figure 2 A flowchart illustrating the high-frequency signal acquisition method for grounding resistance of this invention. Detailed Implementation

[0034] Example 1

[0035] The technical solution of this invention will be described in detail below, taking into account the specific application scenario of 110kV transmission line towers in the mountainous areas of southern China, so that those skilled in the art can fully and accurately understand and reproduce this invention. The tower grounding system adopts a four-point grounding method at the tower feet, and the grounding body is a combination structure of galvanized flat steel and vertical grounding electrode.

[0036] like Figure 1 As shown, this acquisition system consists of five parts: a signal transmitting unit, a signal receiving unit, an adapter fixing mechanism, and a control and power supply unit.

[0037] The signal transmitting unit is used to generate and transmit high-frequency excitation signals with adjustable curvature, and includes an excitation signal generation module, a beamforming module and a power amplification module connected in sequence.

[0038] The excitation signal generation module uses a frequency-adjustable high-frequency signal generator with an output frequency range of 10kHz to 5MHz. It supports two excitation modes: sine wave and frequency-modulated signal. The signal amplitude can be adaptively adjusted within the range of 0.5V to 10V via the control module. In this embodiment, the initial configuration is a 500kHz sine wave excitation signal.

[0039] The beamforming module integrates an Airy beam generator and a neural network inference unit. The neural network inference unit adopts a multilayer perceptron structure and is deployed in the microcontroller of the control module.

[0040] Environmental occlusion information includes: the relative distance d between the obstacle and the transmitting unit. i ; The azimuth angle θ of the obstacle relative to the launching unit i ; The height or size h of the obstacle i ; Whether the obstacle is located on the path connecting the transmitting unit and the receiving unit is marked by the indicator b. i ; Extract fixed-dimensional feature vectors from the raw environmental information and use them as input to the neural network; Distance to nearest obstacle: The distance d from the nearest obstacle to the launching unit min ; Nearest obstacle azimuth angle: the azimuth angle θ of the obstacle relative to the transmitting unit. min ; Nearest obstacle height: The height h of the obstacle min ; Obstruction path indicator: Whether the connection between the transmitting unit and the receiving unit is obstructed (0 / 1); Obstruction angle range: The angular range Δθ occupied by the obstacle in the field of view of the transmitting unit; Number of obstacles: The total number N of obstacles detected in the field of view; Line-of-sight path loss estimation: The amount of signal attenuation along the line of sight, estimated based on obstacle distribution; Current excitation signal frequency: used to assist the network in determining the impact of frequency on diffraction capability; Training data for neural networks is obtained through the following two methods: Electromagnetic simulation data: A three-dimensional electromagnetic model of the tower grounding measurement scenario is constructed using electromagnetic simulation software (such as CST, HFSS, COMSOL) to simulate the beam propagation process under different obstacle layouts. Specific steps: Set the positions of the transmitting and receiving units in the simulation model; Multiple sets of obstacle layouts are randomly generated, including the number of obstacles, distance, azimuth angle, height, and size. For each set of obstacle layouts, traverse the curvature κ from 0.01 rad / m to 0.1 rad / m with a step size of 0.005 rad / m; record the receiver signal strength or signal-to-noise ratio corresponding to each curvature under each set of layouts; Select the curvature value κ that optimizes the received signal quality. o This serves as the training label for this layout.

[0041] Field measurement data: Prototype devices were deployed in typical pole / tower scenarios (mountainous areas, forest areas, urban areas, and open areas). Curvature was manually scanned and the received signal quality was recorded to accumulate measured training samples. The measured data was used for transfer learning and fine-tuning of the simulation-trained model, improving its adaptability to real-world environments.

[0042] Training methods Loss function: Mean square error ; Optimizer: Adam, initial learning rate 0.001, batch size 32; Regularization: Dropout probability 0.2 to prevent overfitting; Data augmentation: Apply random perturbations to the position and size of obstacles to improve the model's generalization ability.

[0043] After training, the model is quantized to 8-bit, converting the weights and activation values ​​from 32-bit floating-point numbers to 8-bit integers, reducing storage and computational overhead and facilitating embedded deployment.

[0044] Neural network inference: Environmental perception sensors scan the surrounding environment at fixed intervals (e.g., 100ms) to acquire obstacle information; The preprocessing module converts the raw information into feature vectors; The preprocessed data is then input into the quantized neural network model. Network output target beam curvature κ t ; κ t Output to the beamforming control module.

[0045] The Airy beam generator achieves beam curvature adjustment based on the phase modulation principle, with a curvature adjustment range of 0.01~0.1 rad / m. Its phase modulation distribution satisfies:

[0046] In the formula, λ is the signal wavelength, and R0 is the wavefront curvature radius. The overall curvature of the beam can be changed by adjusting R0.

[0047] The network consists of 8 input nodes, two hidden layers (64 neurons in the first hidden layer and 32 neurons in the second hidden layer, both with ReLU activation function) and 1 output node (Sigmoid activation function, output range [0,1]).

[0048] The target beam curvature is obtained through the following linear mapping:

[0049] This ensures that the output curvature strictly falls within the design range of 0.01 to 0.1 rad / m. The neural network model is stored after 8-bit quantization, reducing the computing power and storage overhead of embedded deployments.

[0050] The power amplifier module uses a GaN (gallium nitride) power amplifier with a maximum output power of 20W and a gain adjustment range of 10dB~40dB. It can ensure that high-frequency signals have no significant attenuation within a 50m transmission distance, meeting the long-distance transmission requirements of poles in mountainous areas.

[0051] The signal transmission unit is used to achieve stable signal transmission between the transmitter and receiver. It includes a wired transmission module, a rotation adapter module, and a wireless blind spot filling module. The three modes are switched and activated by the control module according to environmental conditions.

[0052] The wired transmission module uses high-frequency coaxial cable with a double-layer copper wire braided shielding mesh on the outer layer and an additional permalloy electromagnetic shielding sleeve, which can effectively suppress electromagnetic interference generated by the power frequency electric field of the transmission line and lightning pulses. Both ends of the cable use N-type waterproof sealed joints, suitable for outdoor rain, snow, and high humidity environments.

[0053] For rotating components such as the antenna support at the top of the tower, a high-frequency rotating slip ring is configured to ensure continuous and low-loss transmission of high-frequency signals during rotation.

[0054] When wired transmission links cannot be deployed, it is activated by using the ultra-high frequency wireless transmission band, based on the curve sphere dynamic path optimization algorithm, combined with the bending beam transmission capability of the beamforming module, to adapt to the distribution of environmental obstacles in real time and achieve reliable signal transmission under non-line-of-sight conditions.

[0055] The signal receiving unit is used to acquire, process, and temporarily store ground response signals, and includes a signal acquisition module, a signal processing module, and a data storage module that are connected in sequence.

[0056] Signal acquisition module: It adopts a high-precision lock-in amplifier to synchronously acquire the amplitude and phase information of the induced signal. The sampling rate is 1MHz and the resolution is 16-bit. It can capture weak grounding response signals at the μV level and is suitable for weak signal acquisition needs in high soil resistivity scenarios.

[0057] The signal processing module consists of an adaptive bandpass filter, a time-frequency analysis unit, and a phase decoupling unit connected in sequence. The center frequency of the adaptive bandpass filter is adjusted synchronously with the excitation signal frequency in real time, and its bandwidth can be dynamically configured within the range of 1kHz to 5MHz. The time-frequency analysis unit uses a short-time Fourier transform (STFT) algorithm to effectively suppress 50Hz power frequency interference and random pulse discharge interference. The phase decoupling unit is used to separate the resistive and reactive components in the signal, extracting six effective characteristic parameters: resistive amplitude, phase difference, signal-to-noise ratio, attenuation coefficient, real part of complex impedance, and imaginary part of complex impedance. After processing by this module, the signal-to-noise ratio of the output signal can be improved to over 40dB.

[0058] The data buffer module is equipped with 8GB of high-speed NAND flash memory, which supports local circular caching of measurement data. The caching time for a single set of measurement data is no less than 30 days, which can avoid the loss of measurement data due to wireless transmission interruption.

[0059] Used for on-site installation and fixing of various units of the data acquisition system, including pole and tower mounting components and grounding electrode fixing components.

[0060] The tower mounting assembly adopts an adjustable clamp structure, suitable for tower main members with diameters ranging from 100mm to 300mm. A 3mm thick anti-slip rubber pad is installed on the inner side of the clamp to increase static friction and prevent slippage after installation; the entire assembly is treated with hot-dip galvanizing for corrosion protection. In this embodiment, the signal receiving unit is fixed to the tower main member at a height of 3m above the ground using this assembly.

[0061] The grounding electrode fixing assembly uses a magnetic mounting base, which can be directly attached to the surface of the tower foot grounding flat steel. The mounting base has a built-in 5mm thick epoxy resin insulating pad to achieve electrical isolation between the transmitting unit and the grounding electrode, preventing the grounding electrode fault current from impacting the transmitting unit. It also has pre-drilled bolt holes to accommodate concrete grounding electrode installation scenarios where magnetic attachment is not possible. In this embodiment, the signal transmitting unit is mounted on a ground support 1.5m away from the tower foot grounding electrode using this assembly.

[0062] The control and power supply unit is used for system scheduling and energy supply, and includes a control module and a power supply module.

[0063] The control module uses an STM32H7 series 32-bit microcontroller as the main control core and integrates Bluetooth 5.0 and 4G communication interfaces. It supports local parameter configuration and on-site debugging via Bluetooth, and remotely uploads measurement data to the smart grid operation and maintenance platform via 4G network. It also undertakes the full system scheduling functions such as excitation signal frequency configuration, beam curvature adjustment, transmission mode switching, and signal processing flow control.

[0064] The power supply module adopts a dual power supply mode of solar energy + lithium battery, equipped with a 10W flexible solar panel and a 12V / 10Ah lithium iron phosphate battery pack. Under sunny conditions, the solar panel provides power and charges the lithium battery, while in cloudy or rainy weather, it automatically switches to lithium battery power, providing a continuous battery life of ≥72 hours without sunlight. The power supply module integrates overcharge, over-discharge, and short-circuit protection circuits to ensure safe and reliable power supply in the field.

[0065] Example 2

[0066] Based on the above acquisition system, the high-frequency signal acquisition method for grounding resistance in this embodiment specifically performs the following steps, and the overall flowchart is shown below. Figure 2 As shown: S1. System on-site deployment The signal transmitting unit is fixed 1.5m away from the grounding flat steel at the base of the tower using the grounding fixing assembly. It is confirmed that the insulating pad of the fixing seat is in close contact with the grounding flat steel to achieve complete electrical isolation. The signal receiving unit is mounted on the main structure of the tower 3m above the ground using the tower mounting assembly. The receiving direction is adjusted to align with the approximate location of the transmitting unit. The wiring and power supply of the control and power supply units are completed, and the self-test of each module of the system is confirmed to be normal.

[0067] S2, System Parameter Configuration and Transmission Mode Adaptation S21. Environmental and Soil Parameter Acquisition: The soil resistivity of the area where the tower is located was measured on-site using the four-pole method. In this embodiment, the average soil resistivity was measured to be 320 Ω·m. The environmental sensing sensor integrated in the transmitting unit was used to scan a fan-shaped area with a radius of 15m and an angle of ±60° centered on the transmitting unit to obtain environmental obstruction information: There are two trees on the transmission and reception path, the nearest obstacle is 8.2m away, the relative azimuth angle of the obstacle is +14°, the obstacle height is 6.5m, the direct line of sight is completely blocked, and the complex terrain on site makes it impossible to lay wired transmission cables.

[0068] S22. Determining the excitation signal frequency: Call the preset soil resistivity-excitation frequency mapping relationship. When the soil resistivity is in the range of 200~500Ω·m, the excitation signal frequency is selected as 300kHz~800kHz. In this embodiment, the initial excitation signal frequency is set to a 500kHz sine wave.

[0069] S23. Transmission mode selection: Based on the environmental obstruction determination result, there is an obstruction between the transmitting unit and the receiving unit and a wired transmission link cannot be laid. Therefore, the wireless blind spot compensation transmission mode is selected, and the beamforming function is enabled simultaneously.

[0070] If the scene is an open and flat area with a direct line of sight and where wiring is possible, select the wired transmission mode; if the signal transmission path passes through the rotating antenna support at the top of the tower, select the wired transmission mode and enable the rotation adapter module to achieve continuous signal transmission at the rotating part through a high-frequency rotating slip ring.

[0071] S24. Initial beam curvature calculation and configuration: The collected environmental occlusion information was preprocessed into an 8-dimensional feature vector, specifically: nearest obstacle distance 8.2m, nearest obstacle azimuth angle +14°, nearest obstacle height 6.5m, occlusion path marker 1, occlusion angle range 13°, number of obstacles 2, line-of-sight path loss estimate 26dB, and current excitation signal frequency 500kHz.

[0072] The feature vector is input into the quantized multilayer perceptron neural network model, and the network output value is linearly mapped to obtain the initial target beam curvature of 0.063 rad / m.

[0073] The control module calculates the corresponding wavefront curvature radius R0 based on the target beam curvature, configures the phase modulation parameters of the Airy beam generator, and enables the high-frequency excitation signal to be transmitted along a curved trajectory with a curvature of 0.063 rad / m, bypassing tree obstructions to reach the receiving unit.

[0074] S25. Beam curvature dynamic iterative optimization: The signal receiving unit measures the received signal quality in real time. In this embodiment, the initial received signal-to-noise ratio is 27dB, which is lower than the preset acceptable threshold of 35dB, thus triggering the beam curvature update process. The current environmental occlusion feature vector and the received signal quality features (received signal strength, signal-to-noise ratio) are input into the neural network model, and the updated target beam curvature of the network output is 0.074 rad / m; The difference between the current curvature and the updated curvature is calculated to be 0.011 rad / m, which is greater than the set threshold of 0.002 rad / m. Therefore, the beam curvature is adjusted to 0.074 rad / m. After adjustment, the received signal-to-noise ratio is checked again and reaches 42dB, which meets the preset threshold requirement. Curvature update is stopped and the current beam parameters are locked.

[0075] If the requirements are still not met after adjustment, repeat the above iterative process until the signal quality meets the standard or the curvature change is less than the threshold.

[0076] S3, Signal Acquisition, Processing and Output After the system parameters stabilize, the excitation signal generation module outputs a 500kHz sinusoidal excitation signal, which is amplified by the power amplifier module and radiated into the grounding system in the form of a curved beam to excite the electromagnetic response of the grounding body. The signal acquisition module synchronously acquires the raw amplitude and phase data of the grounding response signal through a lock-in amplifier; The signal processing module sequentially performs adaptive bandpass filtering to remove out-of-band noise, short-time Fourier transform to suppress power frequency and pulse interference, and phase decoupling to separate resistive and reactive components, finally extracting effective characteristic parameters such as resistive amplitude, phase difference, and real part of complex impedance; The extracted feature parameters are stored locally in the data storage module for backup, and transmitted in real time to the back-end measurement system via the 4G network. The back-end system calculates the measured value of the grounding resistance of the current grounding system based on the preset grounding resistance inversion algorithm.

[0077] This embodiment can complete the measurement without disconnecting the grounding lead. It effectively bypasses the obstruction of trees in mountainous areas by using curved beam technology. Combined with a double-layer shielding structure and digital signal processing algorithm, the measurement signal has a high signal-to-noise ratio and the relative error of grounding resistance measurement is significantly reduced. It can realize all-weather online continuous monitoring and significantly improve the efficiency, accuracy and operational safety of grounding resistance detection in complex terrain.

[0078] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A high-frequency signal acquisition system for grounding resistance in a grounding system, characterized in that, include: The signal transmitting unit includes an excitation signal generation module, a beamforming module, and a power amplification module; the excitation signal generation module is used to generate a frequency-adjustable high-frequency excitation signal, the beamforming module is used to adjust the beam curvature so that the high-frequency signal is transmitted along a curved trajectory, and the power amplification module is used to amplify the power of the high-frequency signal. The signal transmission unit includes a wired transmission module, a rotation adapter module, and a wireless blind spot filling module; the wired transmission module is used to transmit signals through a shielded cable, the rotation adapter module is used to maintain continuous signal transmission at rotating parts, and the wireless blind spot filling module is used to provide a wireless transmission link when wired transmission cannot be deployed. The signal receiving unit includes a signal acquisition module, a signal processing module, and a data storage module; the signal acquisition module is used to acquire received signals, the signal processing module is used to filter and decouple the received signals and extract effective feature parameters, and the data storage module is used to locally cache measurement data. The adapter fixing mechanism includes a tower mounting assembly and a grounding body fixing assembly. The tower mounting assembly is used to mount the receiving unit on the tower, and the grounding body fixing assembly is used to fix the transmitting unit near the grounding body and electrically isolate the transmitting unit from the grounding body. And, a control and power supply unit, which includes a control module and a power supply module; The control module is used to configure the excitation signal frequency, beam curvature and transmission mode, and to communicate with the outside world. The power supply module is used to power the entire acquisition system.

2. The high-frequency signal acquisition system for grounding resistance in a grounding system according to claim 1, characterized in that, The beamforming module integrates an Airy beam generator, which controls the beam curvature by adjusting the phase modulation parameters.

3. The high-frequency signal acquisition system for grounding resistance in a grounding system according to claim 2, characterized in that, The beamforming module has a neural network inference unit, which is used to output the target beam curvature based on environmental perception information and received signal quality information, thereby realizing dynamic adjustment of the beam curvature.

4. The high-frequency signal acquisition system for grounding resistance in a grounding system according to claim 1, characterized in that, The wired transmission module is a high-frequency coaxial cable, the rotary adapter module is a high-frequency rotary slip ring, and the wireless blind spot filling module is an ultra-high frequency wireless transmission module.

5. The high-frequency signal acquisition system for grounding resistance in a grounding system according to claim 1, characterized in that, The tower mounting assembly is an adjustable clamp. The outer side of the clamp is equipped with mounting lugs for installing the receiving unit and for adjusting the pitch and horizontal azimuth angles. The grounding body fixing assembly adopts a magnetic fixing seat or a bolt fixing seat, which is attracted or clamped to the grounding flat steel or the surface of the grounding electrode.

6. A method for acquiring high-frequency signals of grounding resistance in a grounding system, based on the system described in any one of claims 1-5, characterized in that, The method includes the following steps: S1. The transmitting unit is fixed near the grounding body by an adapter fixing mechanism, and the receiving unit is mounted on the middle of the tower or at the foot of the tower. S2. Determine the excitation signal frequency based on soil resistivity information, select the signal transmission mode based on environmental occlusion information, and output the target beam curvature based on neural network in wireless blind spot transmission mode. S3. After the receiving unit acquires the high-frequency excitation signal generated by the transmitting unit, it performs filtering and decoupling processing, extracts effective feature parameters, and transmits the effective feature parameters to the back-end measurement system for grounding resistance inversion calculation.

7. The method for high-frequency signal acquisition of grounding resistance in a grounding system according to claim 6, characterized in that, Step S2 specifically includes: S21. Obtain soil resistivity information and environmental shading information around the tower; S22. Determine the excitation signal frequency from the preset correspondence based on the soil resistivity information; S23. Select the signal transmission mode based on environmental obstruction information; When the selected signal transmission mode is wireless blind spot filling transmission mode, the environmental occlusion information is input into the pre-trained neural network model, and the neural network model outputs the target beam curvature. S24. Configure signal transmission according to the determined excitation signal frequency and signal transmission mode; In the wireless blind spot transmission mode, the phase modulation parameters of the Airy beam generator are adjusted according to the curvature of the target beam so that the high-frequency excitation signal is transmitted in a curved trajectory corresponding to the curvature of the target beam. S25. Obtain the received signal quality information fed back by the receiving unit. When the received signal quality is lower than the preset threshold, repeat the above steps to update the configuration parameters until the received signal quality meets the preset conditions.

8. The method for high-frequency signal acquisition of grounding resistance in a grounding system according to claim 6, characterized in that, Step S23 specifically includes: The signal transmission mode is selected based on the relative distance between the obstacle and the transmitting unit, the azimuth angle of the obstacle relative to the transmitting unit, or the size of the obstacle: When there is a direct line of sight between the transmitting unit and the receiving unit and wiring is possible, select the wired transmission mode; When the signal path passes through the tower's rotating components, select wired transmission mode and enable rotational adaptation transmission mode; When there are obstructions and wired transmission links cannot be deployed, select the wireless blind spot filling transmission mode.

9. The method for high-frequency signal acquisition of grounding resistance in a grounding system according to claim 6, characterized in that, The neural network model in step S23 can be any one of a multilayer perceptron, a convolutional neural network, or a deep reinforcement learning network, and the target beam curvature ranges from 0.01 to 0.1 rad / m.

10. A method for acquiring high-frequency signals of grounding resistance in a grounding system according to claim 6, characterized in that, Step S25 specifically includes: The current environmental perception information, the current beam curvature, and the latest received signal quality information are input into the neural network model to obtain the updated target beam curvature. The received signal quality information includes at least one of received signal strength indication, signal-to-noise ratio, and bit error rate. If the difference between the updated target beam curvature and the current beam curvature is less than a set threshold, or if the received signal quality meets preset conditions, the update will stop.

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