Grounding resistance detection method and device in high-voltage test and computer equipment

Abstract

The invention relates to a ground resistance detection method and device in a high-voltage test, computer equipment, a computer readable storage medium and a computer program product. The method comprises the following steps: injecting a pilot frequency sine wave signal of a non-power frequency harmonic wave into a grounding loop in a high-voltage test, and collecting a response signal in the grounding loop; performing multi-stage filtering processing on the acquired response signal to obtain an effective amplitude and a signal characteristic of the response signal; calculating a grounding resistance value of the grounding loop based on the effective amplitude and the signal characteristics of the response signal; the grounding resistance value is compared with a preset resistance threshold value, and whether a preset abnormal factor exists in the grounding loop or not is analyzed; and when the grounding resistance value exceeds a preset resistance threshold value and / or the grounding loop has a preset abnormal factor, triggering an alarm and controlling the high-voltage test equipment to be powered off. By adopting the method, the grounding resistance can be detected in a non-direct contact manner in a high-voltage test.

Description

Technical Field

[0001] The present application relates to the field of resistance detection technology, and in particular to a method, device, computer equipment, computer-readable storage medium, and computer program product for detecting ground resistance in high-voltage testing. Background Art

[0002] During high-voltage cable electrical testing (such as withstand voltage testing and partial discharge testing) and fault location (such as cable routing and precise fault location), the grounding system is a key element in ensuring operational safety. Its key functions include: In the event of insulation breakdown or flashover in equipment or cables, a reliable grounding system can quickly conduct the fault current to the ground, preventing electric shock; providing a low-impedance discharge path for high-voltage test equipment, protecting it from damage; suppressing electromagnetic interference and static electricity accumulation, ensuring accurate and repeatable test results; and eliminating induced voltages on metal objects near high-voltage cables, ensuring the safety of workers. Therefore, the reliability of the grounding system is fundamental to high-voltage operational safety.

[0003] However, existing grounding detection technology for high-voltage cable testing and fault location operations has numerous limitations. First, grounding operations rely on manual labor and are uncontrollable. Grounding wires are often temporarily clamped in non-standard locations on site, resulting in poor stability and prone to detachment. Furthermore, manual periodic testing fails to reflect dynamic changes, making it difficult to promptly detect grounding system degradation or failure. Second, there is a lack of real-time monitoring, real-time linkage with system equipment, and intelligent control capabilities. Most systems rely on manual identification and handling during high-voltage testing. Grounding monitoring and test equipment are independent of each other, making rapid fault response and closed-loop control impossible. Alarm methods are limited, resulting in ineffective warnings. Furthermore, most existing systems are unable to achieve real-time, high-precision online measurement of ground resistance. Measurements in strong electromagnetic interference environments are unstable, or even ineffective. Some online grounding detection devices use direct contact measurement, which carries the risk of electric shock and short circuits. This can serve as a channel for electrical fault propagation, increasing system operational risks.

[0004] Therefore, there is an urgent need for a method, device, computer equipment, computer-readable storage medium and computer program product for detecting ground resistance in high-voltage testing, which can detect ground resistance in a non-direct contact manner in high-voltage testing. Summary of the Invention

[0005] Based on this, it is necessary to provide a ground resistance detection method, device, computer equipment, computer-readable storage medium and computer program product in high-voltage testing that can detect ground resistance in a non-direct contact manner during high-voltage testing to address the above technical problems.

[0006] In a first aspect, the present application provides a method for detecting ground resistance in a high voltage test, comprising:

[0007] In high-voltage testing, a non-power frequency sinusoidal signal is injected into the ground loop, and the response signal in the ground loop is collected;

[0008] Perform multi-stage filtering on the collected response signal to obtain the effective amplitude and signal characteristics of the response signal;

[0009] Calculate the grounding resistance value of the grounding loop based on the effective amplitude and signal characteristics of the response signal;

[0010] Comparing the grounding resistance value with a preset resistance threshold, and analyzing whether there is a preset abnormal factor in the grounding loop;

[0011] When the grounding resistance value exceeds a preset resistance threshold and / or there is a preset abnormal factor in the grounding loop, an alarm is triggered and the high-voltage test equipment is controlled to be powered off.

[0012] In one embodiment, injecting a non-power frequency harmonic sine wave signal into the ground loop during the high voltage test and collecting a response signal in the ground loop includes:

[0013] Generates a non-power frequency harmonic sine wave signal with a frequency lower than a preset Hz;

[0014] Injecting a non-power frequency harmonic sinusoidal signal into the ground loop by magnetic coupling;

[0015] Collect the response signal generated by the different-frequency sine wave signal in the ground loop.

[0016] In one embodiment, the multi-stage filtering of the collected response signal to obtain the effective amplitude and signal characteristics of the response signal includes:

[0017] Performing preliminary processing on the collected response signal, the preliminary processing methods include programmable gain amplification, band-stop filtering, band-pass filtering and low-pass filtering;

[0018] Performing analog-to-digital conversion on the response signal after preliminary processing to obtain a response signal in digital format;

[0019] The digital response signal is subjected to software filtering to obtain the effective amplitude and signal characteristics of the response signal.

[0020] In one embodiment, the heterodyne sine wave signal includes at least two excitation signals of different frequencies; and the calculating the grounding resistance value of the ground loop based on the effective amplitude and signal characteristics of the response signal includes:

[0021] Based on the effective amplitudes and signal characteristics of the response signals corresponding to the at least two excitation signals of different frequencies, respectively measuring the voltage values ​​and current values ​​of the at least two excitation signals of different frequencies;

[0022] Calculating ground impedance values ​​at different frequencies according to voltage values ​​and current values ​​of the at least two excitation signals of different frequencies;

[0023] Calculate the grounding resistance of the grounding loop based on the grounding impedance values ​​at different frequencies.

[0024] In one embodiment, analyzing whether a ground loop has a preset abnormal factor includes:

[0025] Collect real-time operating data in the grounding loop, and analyze whether there are preset abnormal factors in the grounding loop based on the real-time operating data and historical operating data; the preset abnormal factors include grounding wire breakage, poor contact, loose grounding connection points, corroded grounding body damage and high impedance points in the grounding loop.

[0026] In one embodiment, the method further comprises:

[0027] When the grounding resistance value exceeds the preset resistance threshold and / or there are preset abnormal factors in the grounding loop, the error data is recorded and a pop-up alarm is issued through the terminal.

[0028] In a second aspect, the present application further provides a ground resistance detection device for high voltage testing, comprising:

[0029] The data acquisition module is used to inject a non-power frequency harmonic sine wave signal into the ground loop during high-voltage testing and collect the response signal in the ground loop;

[0030] The data processing module is used to perform multi-stage filtering on the collected response signal to obtain the effective amplitude and signal characteristics of the response signal;

[0031] a calculation module, configured to calculate a ground resistance value of the ground loop based on an effective amplitude and a signal characteristic of the response signal;

[0032] An analysis module, configured to compare the ground resistance value with a preset resistance threshold and analyze whether there are preset abnormal factors in the ground loop;

[0033] The control module is used to trigger an alarm and control the high-voltage test equipment to cut off power when the grounding resistance value exceeds a preset resistance threshold and / or there is a preset abnormal factor in the grounding loop.

[0034] In a third aspect, the present application further provides a computer device comprising a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0035] In high-voltage testing, a non-power frequency sinusoidal signal is injected into the ground loop, and the response signal in the ground loop is collected;

[0036] Perform multi-stage filtering on the collected response signal to obtain the effective amplitude and signal characteristics of the response signal;

[0037] Calculate the grounding resistance value of the grounding loop based on the effective amplitude and signal characteristics of the response signal;

[0038] Comparing the grounding resistance value with a preset resistance threshold, and analyzing whether there is a preset abnormal factor in the grounding loop;

[0039] When the grounding resistance value exceeds a preset resistance threshold and / or there is a preset abnormal factor in the grounding loop, an alarm is triggered and the high-voltage test equipment is controlled to be powered off.

[0040] In a fourth aspect, the present application further provides a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the following steps are implemented:

[0041] In high-voltage testing, a non-power frequency sinusoidal signal is injected into the ground loop, and the response signal in the ground loop is collected;

[0042] Perform multi-stage filtering on the collected response signal to obtain the effective amplitude and signal characteristics of the response signal;

[0043] Calculate the grounding resistance value of the grounding loop based on the effective amplitude and signal characteristics of the response signal;

[0044] Comparing the grounding resistance value with a preset resistance threshold, and analyzing whether there is a preset abnormal factor in the grounding loop;

[0045] When the grounding resistance value exceeds a preset resistance threshold and / or there is a preset abnormal factor in the grounding loop, an alarm is triggered and the high-voltage test equipment is controlled to be powered off.

[0046] In a fifth aspect, the present application further provides a computer program product, comprising a computer program, which, when executed by a processor, implements the following steps:

[0047] In high-voltage testing, a non-power frequency sinusoidal signal is injected into the ground loop, and the response signal in the ground loop is collected;

[0048] Perform multi-stage filtering on the collected response signal to obtain the effective amplitude and signal characteristics of the response signal;

[0049] Calculate the grounding resistance value of the grounding loop based on the effective amplitude and signal characteristics of the response signal;

[0050] Comparing the grounding resistance value with a preset resistance threshold, and analyzing whether there is a preset abnormal factor in the grounding loop;

[0051] When the grounding resistance value exceeds a preset resistance threshold and / or there is a preset abnormal factor in the grounding loop, an alarm is triggered and the high-voltage test equipment is controlled to be powered off.

[0052] The above-mentioned ground resistance detection method, device, computer equipment, computer-readable storage medium, and computer program product in high-voltage testing can more effectively identify abnormal conditions in the ground loop, reduce interference, and improve detection accuracy by injecting a non-power frequency harmonic sinusoidal signal into the ground loop. Multi-stage filtering of the collected response signal can remove noise and unnecessary frequency components, extract the effective amplitude and characteristics of the signal, and thus enhance the reliability and effectiveness of signal processing. Based on the effective amplitude and signal characteristics of the response signal, the ground resistance value of the ground loop can be more accurately calculated, providing accurate data support for ground loop performance evaluation. The calculated ground resistance value is compared with a preset resistance threshold, and the ground loop is analyzed for preset abnormal factors, so that abnormal conditions in the ground loop can be detected in a timely manner and corresponding measures can be taken. If the ground resistance value exceeds the preset resistance threshold and / or the ground loop has a preset abnormal factor, an alarm is triggered and the high-voltage test equipment is powered off, which can effectively prevent equipment damage and electric shock accidents, ensuring the safety of equipment and personnel. Through automated monitoring and analysis processes, ground loop problems can be quickly located, reducing maintenance time and costs and improving maintenance efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the following briefly introduces the drawings required for use in the embodiments of the present application or related technical descriptions. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying any creative work.

[0054] Figure 1 This is a diagram showing an application environment of a method for detecting ground resistance in a high voltage test according to an embodiment;

[0055] Figure 2 A schematic diagram of a flow chart of a method for detecting ground resistance in a high voltage test according to an embodiment;

[0056] Figure 3 A schematic flow chart of a method for detecting ground resistance in a high voltage test in another embodiment;

[0057] Figure 4 This is a schematic structural diagram of a high-voltage cable fault location system in the most detailed embodiment;

[0058] Figure 5 This is a structural diagram of a ground detection module in the most detailed embodiment;

[0059] Figure 6 A schematic diagram of multi-stage filtering of the hardware signal conditioning process in the most detailed embodiment;

[0060] Figure 7 1 is a structural block diagram of a ground resistance detection device in a high voltage test according to an embodiment;

[0061] Figure 8 FIG. 1 is a diagram showing the internal structure of a computer device in one embodiment. DETAILED DESCRIPTION

[0062] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0063] It should be noted that the terms "first", "second", etc. used in this application may be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "including" and "having" used in this application and any variations thereof are intended to cover non-exclusive inclusions. The term "plurality" used in this application refers to two or more. The term "and / or" used in this application refers to one of the solutions or any combination of multiple solutions.

[0064] The ground resistance detection method in high voltage test provided by the embodiment of the present application can be applied to Figure 1 In the application environment shown, the terminal 102 communicates with the server 104 via a network. The data storage system can store data that the server 104 needs to process. The data storage system can be integrated on the server 104 or placed on the cloud or other network servers.

[0065] Terminal 102 may include, but is not limited to, various personal computers, laptops, smartphones, tablets, IoT devices, and portable wearable devices. IoT devices may include smart speakers, smart TVs, smart air conditioners, smart car devices, and projectors. Portable wearable devices may include smart watches, smart bracelets, and head-mounted devices. Head-mounted devices may include virtual reality (VR) devices, augmented reality (AR) devices, smart glasses, and the like. Server 104 may be a standalone physical server, a server cluster or distributed system consisting of multiple physical servers, or a cloud server providing cloud computing services.

[0066] In an exemplary embodiment, Figure 2 As shown, a method for detecting ground resistance in high voltage test is provided. Figure 1 The server in the example is used to illustrate the method, which includes the following steps S202 to S210.

[0067] Step S202: In a high-voltage test, a sinusoidal signal of a different frequency that is not a power frequency harmonic is injected into the ground loop, and a response signal in the ground loop is collected.

[0068] Specifically, to avoid interference with the grid's main frequency (typically 50 Hz or 60 Hz) and its higher harmonics, a non-power frequency harmonic signal—a sinusoidal signal with a frequency different from the grid frequency—is injected. This ensures a high signal-to-noise ratio and spectral clarity during signal transmission and analysis. This off-frequency sinusoidal signal is injected into the ground wire in the ground loop via magnetic coupling via an excitation sensor. The injected signal is expressed as V(t) = A × sin(2πft), where V(t) is the signal voltage at time t, A is the signal amplitude, f is the signal frequency, and t is the time variable.

[0069] Using high-precision and high-isolation sampling sensors, the signal injected into the ground loop, the sampling process and feature extraction adopt a multi-stage filtering method coordinated by software and hardware to ensure that the signal maintains a high signal-to-noise ratio and spectrum clarity during transmission and analysis.

[0070] Step S204: performing multi-stage filtering on the collected response signal to obtain the effective amplitude and signal characteristics of the response signal.

[0071] Specifically, multistage filtering is designed to gradually remove noise and unwanted frequency components from a signal while preserving useful signal features, thereby improving signal quality and analysis accuracy. Multistage filtering typically involves multiple stages of filtering, each of which may utilize different types of filters (such as low-pass filters, high-pass filters, band-pass filters, and band-stop filters) to target different frequency components.

[0072] The effective amplitude of the response signal is obtained. The effective amplitude refers to the strength or magnitude of useful information in the signal. It is a key parameter in signal analysis and can be used to assess the strength or energy of the signal. After filtering, the effective amplitude can be extracted from the purified signal. This typically involves calculating the signal's statistical properties, such as the average, peak, and RMS values.

[0073] Obtain signal features, where signal features refer to specific properties or parameters of a signal, such as frequency, phase, and waveform shape. These features can reflect the intrinsic characteristics and behavior of the signal. Signal features can be obtained through various signal processing techniques, such as Fourier transform (for analyzing frequency components), wavelet transform (for analyzing time-frequency characteristics), and Hilbert transform (for obtaining envelope and instantaneous frequency).

[0074] Among them, a multi-stage filtering method that combines software and hardware can also be used, including:

[0075] Hardware filtering: At the analog signal stage, a physical filter (such as a filter circuit composed of electronic components) is used to filter out signals of specific frequencies.

[0076] Software filtering: At the digital signal stage, digital signal processing algorithms (such as sliding average filtering, median filtering, Kalman filtering, etc.) are used to further process the signal to extract more accurate features.

[0077] Step S206 : calculating the grounding resistance value of the ground loop based on the effective amplitude and signal characteristics of the response signal.

[0078] Specifically, after filtering, the effective amplitude and signal characteristics are extracted from the signal. The effective amplitude refers to the portion of the signal that contains useful information, while signal characteristics may include frequency, phase, waveform, etc. Using the extracted effective amplitude and signal characteristics, the impedance of the ground loop can be calculated. Impedance is a complex number that represents the circuit's resistance to alternating current and is composed of resistance (R) and reactance (X), i.e., Z = R + jX. In an AC circuit, the relationship between voltage (V) and current (I) is determined by impedance (Z), i.e., V = IZ. By measuring the voltage and current at different frequencies, the impedance at the corresponding frequencies can be calculated. Then, the resistance component, i.e., the ground resistance value, is extracted from the impedance.

[0079] Step S208 : comparing the ground resistance value with a preset resistance threshold, and analyzing whether there is a preset abnormal factor in the ground loop.

[0080] Specifically, the preset resistance threshold is a safety limit set based on power system safety standards and equipment technical requirements. This value is typically specified by equipment manufacturers, power industry standards, or safety regulations. The preset resistance threshold ensures that the grounding system can effectively conduct fault currents to the ground, thereby protecting equipment and personnel. If the ground resistance exceeds this threshold, the grounding system may not function effectively, increasing the risk of electric shock and equipment damage.

[0081] If the measured ground resistance value is less than or equal to the preset resistance threshold, the grounding system is in good condition and can effectively protect equipment and personnel. If the measured ground resistance value exceeds the preset resistance threshold, it indicates that there may be a problem with the grounding system and further inspection and analysis is required.

[0082] The preset abnormal factors may include broken ground wires, poor contact, loose ground connection points, corrosion or damage to the ground body, etc. These factors may cause the ground resistance value to increase.

[0083] Analytical methods include:

[0084] Historical data comparison: Compare the current ground resistance value with historical data to analyze whether there are significant changes.

[0085] Site Inspection: Perform a site inspection of the grounding system to check for any obvious physical damage or connection problems.

[0086] Signal feature analysis: Analyze the characteristics of the response signal, such as frequency, phase, waveform, etc., to identify possible abnormal patterns.

[0087] Step S210 , when the grounding resistance value exceeds a preset resistance threshold and / or there is a preset abnormal factor in the grounding loop, triggering an alarm and controlling the high-voltage test equipment to be powered off.

[0088] Specifically, when the monitored ground resistance value exceeds the preset resistance threshold or an abnormal factor is detected in the ground loop, the system will trigger an alarm. The alarm can be carried out through audible and visual alarms, warning lights, buzzers, or software notifications on smart terminals (such as mobile phones and tablets) to ensure that operators can receive alarm information in a timely manner. When the alarm is triggered, the system will automatically control the high-voltage test equipment to cut off the power and stop the ongoing high-voltage test or operation to prevent the fault current from causing damage to equipment and personnel. Power outages can be achieved through electrical components such as circuit breakers, contactors, or relays. These components can quickly cut off the power supply to ensure the safe shutdown of the high-voltage test equipment.

[0089] In the above-mentioned ground resistance detection method for high-voltage testing, by injecting a non-power frequency harmonic sinusoidal signal into the ground loop, abnormalities in the ground loop can be more effectively identified, interference can be reduced, and detection accuracy can be improved. Multi-stage filtering of the collected response signal can remove noise and unnecessary frequency components, extract the effective amplitude and characteristics of the signal, and thus enhance the reliability and effectiveness of signal processing. Based on the effective amplitude and signal characteristics of the response signal, the ground resistance value of the ground loop can be more accurately calculated, providing accurate data support for ground loop performance evaluation. The calculated ground resistance value is compared with a preset resistance threshold, and the ground loop is analyzed for preset abnormal factors. Abnormal conditions in the ground loop can be promptly detected and appropriate measures can be taken. If the ground resistance value exceeds the preset resistance threshold and / or the ground loop has preset abnormal factors, an alarm is triggered and the high-voltage test equipment is powered off, effectively preventing equipment damage and electric shock accidents, ensuring the safety of equipment and personnel. Through automated monitoring and analysis processes, ground loop problems can be quickly located, reducing maintenance time and costs, and improving maintenance efficiency.

[0090] In an exemplary embodiment, Figure 3 As shown in the figure, during the high voltage test, a non-power frequency sinusoidal wave signal is injected into the ground loop, and the response signal in the ground loop is collected, including:

[0091] Step S302, generating a non-power frequency sinusoidal wave signal with a frequency lower than a preset hertz by a non-contact magnetic coupling sensor;

[0092] Step S304: driving the excitation sensor to inject a non-power frequency harmonic sinusoidal signal into the ground loop in a magnetic coupling manner;

[0093] Step S306 : collecting a response signal generated in the ground loop based on the heterodyne sine wave signal.

[0094] Specifically, a non-contact magnetic coupling sensor generates a non-power frequency sinusoidal signal with a frequency lower than a preset hertz. Using non-contact sensor technology, direct contact with high-voltage circuits can be avoided, thereby improving safety. Non-power frequency harmonics below a specific frequency (e.g., below 10kHz) are selected to distinguish the signal from the power grid's power frequency (such as 50Hz or 60Hz) and its harmonics, reducing interference and improving measurement accuracy. The excitation sensor is driven to generate and drive a non-power frequency sinusoidal signal. The signal is injected into the ground loop through magnetic coupling. Magnetic coupling is a contactless signal transmission method that avoids electrical contact, reduces interference, and improves safety.

[0095] After injecting a non-power-frequency sinusoidal signal, the ground loop's response signal is collected. This response signal contains information about the ground loop's response to the injected signal, such as changes in voltage and current. The collected response signal may contain noise and other interference. Multi-stage filtering is required to extract useful signal features, such as effective amplitude and signal characteristics.

[0096] In this embodiment, by analyzing the effective amplitude and signal characteristics of the response signal, the impedance of the ground loop can be calculated, thereby evaluating the performance of the grounding system. This method can be used for safety monitoring during high-voltage testing to ensure the reliability and safety of the grounding system during testing. If the ground resistance value exceeds the preset resistance threshold and / or there are abnormal factors in the ground loop, the system can automatically trigger an alarm and control the high-voltage test equipment to cut off power to prevent possible safety accidents. Through this method, the performance of the ground loop can be safely and effectively monitored and evaluated during high-voltage testing, improving the safety and reliability of the power system.

[0097] In an exemplary embodiment, the collected response signal is subjected to multi-stage filtering to obtain the effective amplitude and signal characteristics of the response signal, including:

[0098] Performing preliminary processing on the collected response signal, the preliminary processing methods include programmable gain amplification, band-stop filtering, band-pass filtering and low-pass filtering;

[0099] Performing analog-to-digital conversion on the response signal after preliminary processing to obtain a response signal in digital format;

[0100] The digital response signal is subjected to software filtering to obtain the effective amplitude and signal characteristics of the response signal.

[0101] Specifically, multi-stage filtering of the collected response signal to obtain the effective amplitude and signal characteristics of the response signal is a key step in signal processing, which aims to extract useful information from the original signal and improve the signal quality.

[0102] Among them, preliminary processing aims to adjust and purify the signal to make it more suitable for subsequent analysis and processing.

[0103] Programmable Gain Amplifier (PGA) is used to amplify weak signals to an amplitude suitable for subsequent processing. Band-Stop Filter (BSF) is used to suppress signals within a specific frequency range, such as power frequency interference signals (50Hz or 60Hz), while retaining other frequency components. Band-Pass Filter (BPF) allows signals within a specific frequency range to pass while suppressing other frequency components to ensure that only the frequency components of interest are retained. Low-Pass Filter (LPF) allows frequencies below the specified cutoff frequency to pass, removes high-frequency components that may cause aliasing, and prepares the signal for Analog-to-Digital Conversion (ADC).

[0104] The purpose of analog-to-digital conversion (ADC) is to convert analog signals into digital format for further processing and analysis in the digital domain. The ADC converts a continuous analog signal into discrete digital values ​​that represent the amplitude of the original analog signal at a specific point in time.

[0105] The purpose of software filtering is to further process the signal in the digital domain to extract the effective amplitude and signal characteristics. This includes:

[0106] Sliding average filter: used to smooth the sampling curve, suppress random noise, and effectively smooth spike signals to improve signal stability.

[0107] Median filtering: used to eliminate sudden spike interference and reduce the impact of outliers by taking the median of the sampling points within a certain window.

[0108] Extracting effective amplitude and signal characteristics. Effective amplitude refers to the portion of the signal that contains useful information, such as the peak value and RMS value. These values ​​can be used to assess signal strength or energy. Signal characteristics include frequency, phase, and waveform. These characteristics reflect the intrinsic characteristics and behavior of the signal and are crucial for analyzing ground loop performance.

[0109] In this embodiment, by analyzing the effective amplitude and signal characteristics of the response signal, the impedance of the ground loop can be calculated, thereby evaluating the performance of the grounding system. If the signal characteristics show an abnormal pattern, this may indicate a problem with the ground loop, such as a broken ground wire, poor contact, or corroded grounding body. Through this multi-stage filtering process, high-quality signal features can be extracted from the original signal, providing accurate data support for subsequent analysis and decision-making. This method has important application value in high-voltage testing and grounding system monitoring.

[0110] In an exemplary embodiment, the different-frequency sinusoidal wave signal includes at least two excitation signals of different frequencies; and calculating the ground resistance value of the ground loop based on the effective amplitude and signal characteristics of the response signal includes:

[0111] Based on the effective amplitudes and signal characteristics of the response signals corresponding to the at least two excitation signals of different frequencies, respectively measuring the voltage values ​​and current values ​​of the at least two excitation signals of different frequencies;

[0112] Calculating ground impedance values ​​at different frequencies based on voltage values ​​and current values ​​of at least two excitation signals of different frequencies;

[0113] Calculate the grounding resistance of the grounding loop based on the grounding impedance values ​​at different frequencies.

[0114] Specifically, injecting at least two sinusoidal signals of different frequencies allows for a more comprehensive assessment of ground loop characteristics. This is because the impedance of a ground loop can vary with frequency, particularly considering the effects of inductance and capacitance. These sinusoidal signals of different frequencies are injected into the ground loop via magnetic coupling using an excitation sensor. The frequencies of these signals are intentionally chosen to be non-power frequency to avoid interference with the power-frequency signals of the power grid.

[0115] For each injected stimulus signal, the ground loop response signal is acquired. This response signal contains information about the ground loop's response to the stimulus signal, such as changes in voltage and current. Through multi-stage filtering, the effective amplitude and signal characteristics are extracted from the response signal. These characteristics, including the signal's frequency, phase, and waveform, are crucial for subsequent impedance calculations.

[0116] For each excitation signal at a different frequency, the voltage and current generated in the ground loop are measured. To calculate the ground impedance at each frequency, use the formula Z=UI, where Z is impedance, U is voltage, and I is current. Impedance is a complex number that includes both resistance and reactance (a combination of inductance and capacitance). Extracting the resistive component (real part) from the calculated complex impedance value provides a direct measurement of the ground resistance. By analyzing the impedance at different frequencies, we can more accurately separate the resistive and inductive / capacitive components, thereby determining the ground resistance value.

[0117] In this embodiment, using excitation signals at multiple frequencies can reduce measurement errors and improve the accuracy of ground resistance measurements. By analyzing the impedance at different frequencies, the contributions of resistance, inductance, and capacitance to the total impedance can be distinguished, which is crucial for understanding and optimizing the performance of grounding systems. This method is suitable for applications requiring high accuracy and reliability, such as ground resistance measurement in power systems, ensuring that the grounding system effectively protects equipment and personnel from electrical faults.

[0118] In an exemplary embodiment, analyzing whether a ground loop has a preset abnormal factor includes:

[0119] Collect real-time operating data from the ground loop, and analyze whether there are preset abnormal factors in the ground loop based on the real-time operating data and historical operating data; preset abnormal factors include ground wire breakage, poor contact, loose ground connection points, corroded ground body damage, and high impedance points in the ground loop.

[0120] Specifically, real-time operational data is collected to analyze the ground loop's operating parameters, including voltage, current, and resistance, for immediate analysis. This data is collected using sensors and monitoring devices, which can be fixed or portable, depending on the application scenario and requirements.

[0121] By comparing current real-time data with historical data, you can identify any unusual changes or trends that could indicate a problem with the grounding system. Store historical data in a database or data logging system, then use data analysis tools or software to compare real-time data with historical data.

[0122] Identify and analyze specific issues that may cause grounding system performance degradation, such as grounding wire breakage, poor contact, etc. Preset abnormal factors include:

[0123] Grounding wire breakage: Physical breakage of the grounding wire will significantly increase the grounding resistance and affect the grounding effect.

[0124] Poor contact: Poor electrical contact can cause increased resistance, affecting the smooth flow of current.

[0125] Loose ground connection points: Loose connection points may cause intermittent high resistance and affect system stability.

[0126] Corrosion damage to the grounding body: Corrosion of the grounding body will reduce its conductivity and increase the grounding resistance.

[0127] There are high impedance points in the ground loop: High impedance points may be caused by material aging, environmental factors or other reasons, which will affect the overall performance of the ground loop.

[0128] In this embodiment, once an abnormality is detected, the system can automatically trigger an early warning or alarm, notifying maintenance personnel to conduct inspections and repairs. Based on the analysis results, timely maintenance and repairs can be performed to restore the normal operation of the grounding system. Real-time monitoring and data analysis enable preventive maintenance, reducing unexpected failures and downtime. Ensuring that the grounding system is always in good condition can improve the safety and reliability of the power system. By promptly identifying and resolving ground loop issues, the performance of the entire power system can be optimized.

[0129] In an exemplary embodiment, the method further includes: when the grounding resistance value exceeds a preset resistance threshold and / or there are preset abnormal factors in the grounding loop, recording error data and issuing a pop-up alarm through the terminal.

[0130] Specifically, when the ground resistance value exceeds a preset threshold or other abnormal factors are detected, the system automatically records relevant error data. This data may include timestamps, specific resistance values, abnormality type, and location. This recorded data is typically stored in the system's database or log files for subsequent analysis and review. Once an abnormality is detected, the system immediately triggers an alarm mechanism, alerting the operator via a pop-up window or other notification method. This pop-up window typically displays a summary of the error, including the type of abnormality, time of occurrence, potential impact, and recommended actions. This pop-up window allows the operator to quickly understand the nature of the problem and take appropriate action, such as checking the ground loop, performing repairs, or adjusting system settings. For example, various fault conditions may include: function switching failure; capacitor switching failure; F-0 ground resistance alarm; FU step voltage alarm; door not closed; high-voltage plunger limit switch failure; system overvoltage; system overcurrent; and system overtemperature.

[0131] In this embodiment, the automated monitoring and alarm system reduces the need for manual monitoring, improving response speed and accuracy. Real-time monitoring and immediate alarms ensure that problems are discovered and addressed promptly. Recorded error data provides a basis for problem tracking and analysis, helping to improve system operation and maintenance strategies.

[0132] The most detailed embodiment of this application is:

[0133] like Figure 4 As shown in the figure, the high-voltage cable fault location system includes: a high-voltage power supply and control module, a wireless routing gateway module, a positioning module and a grounding detection module; the high-voltage output lead is connected to the core wire of the cable under test, and the ground wire of the high-voltage output is connected to the shield of the cable under test and the working ground; the protection ground of the high-voltage cable fault location equipment is connected to the protection ground of the site, thereby forming a grounding loop between the "working ground" and the "protective ground"; the system also includes an intelligent terminal (PAD or mobile computer, etc.).

[0134] The ground detection module mainly includes a central processing unit, a WiFi communication unit, an excitation signal unit, a signal processing unit, an excitation sensor and a sampling sensor. Figure 5 Figure 2 is the block diagram of the ground detection module.

[0135] To avoid interference from the power frequency and its higher harmonics, the central processing unit generates a non-power frequency sinusoidal signal (preferably two frequencies below 10kHz) that is not a harmonic of the power frequency. The excitation signal unit executes the frequency signal output of the central processing unit to drive the excitation sensor, which is then injected into the ground wire in the ground loop by magnetic coupling.

[0136] Signal sampling: High-precision and high-isolation sampling sensors are used to collect the signal injected into the ground loop by the excitation sensor through magnetic coupling. The signal sampling process and feature extraction utilize a multi-stage filtering approach that collaborates with hardware and software to ensure a high signal-to-noise ratio and spectral clarity during signal transmission and analysis. This multi-stage filtering effectively suppresses non-target components in the original received signal, such as transient pulses, electromagnetic noise, and power frequency interference, ultimately extracting a clear and stable excitation response signal waveform.

[0137] a) The hardware signal conditioning process uses multi-stage filtering: Figure 6 As shown, it should be noted that the signal processing unit is mainly filtering and noise reduction, see Figure 6 Specifically, the sampled signal is subjected to programmable gain amplification, band-stop filtering, band-pass filtering, low-pass filtering and analog-to-digital conversion in sequence; the PGA in the figure can amplify weak signals and then output them; BEF is a band-stop filter, which suppresses the power frequency (50Hz) interference signal and then outputs the signal; BPF is a band-pass filter, which outputs the signal at the injection signal frequency point precisely selected within the passband; LPF is a low-pass filter, which allows frequencies below the specified cutoff frequency to pass through, and removes high-frequency components that may cause aliasing during the ADC sampling process; ADC is an analog-to-digital converter, which converts the sampled and conditioned analog signal into a digital format, and quantizes the amplitude into a digital value.

[0138] b) The central processing unit performs software filtering on the data digitized by the signal processing unit. This filtering process significantly improves the accuracy and consistency of subsequent resistance and impedance calculations, effectively avoiding misjudgments and malfunctions caused by signal distortion, and enhancing the system's ability to resolve small ground current changes. This is achieved using a sliding average + median filtering approach.

[0139] The sliding average filter is used to smooth sampling curves, suppress random noise, and effectively smooth spikes. Its mathematical formula is as follows: x_avg[n]=\frac{1}{N}\sum_{i=n-N+1}^{n}x[i]. Here, x_avg[n] is the sliding average (filter output) of the nth sampling point; x[i] is the original input value of the i-th sampling point; N is the size of the sliding window (the length of the filter); n is the index of the current sampling point; and i is the index variable within the summation range.

[0140] Median filtering: Median filtering is used to eliminate sudden spikes. It's implemented by taking a window of N sample points from the current moment forward, sorting them by numerical value, and taking the median value as the filtering result. The formula is: x_med[n]=median(x[n-N+1],...,x[n]). Here, x_med[n] is the median filter result of the nth sample point; x[n] is the original input value of the nth sample point; and median is the function that takes the median value.

[0141] Ground loop impedance calculation method: The system injects excitation signals at two different frequencies f1 and f2, measures the corresponding voltages U1 and U2 and currents I1 and I2, and calculates the ground impedance at different frequencies using the following formula: Z1=U1 / I1=R+jω1L; Z2=U2 / I2=R+jω2L.

[0142] Solving this system of equations yields the ground resistance R and ground inductance L: R = Re(Z) = real part {Z1}; L = (Im(Z2) - Im(Z1)) / (ω2 - ω1). Here, R is the ground resistance; L is the ground inductance; Z is the complex impedance; Z1 is the complex impedance at the first frequency; Z2 is the complex impedance at the second frequency; Re(Z) is the real part of the complex impedance Z; Im(Z) is the imaginary part of the complex impedance Z; ω1 is the angular frequency of the first frequency; and ω2 is the angular frequency of the second frequency.

[0143] The resulting ground resistance value, R, is then compared to the warning threshold. This formula also effectively addresses the issue of excessive inductance introduced when the ground cable is not fully extended, allowing for clear impedance separation.

[0144] It should be understood that, although the various steps in the flowcharts involved in the various embodiments described above are displayed in sequence according to the instructions of the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in the flowcharts involved in the various embodiments described above can include multiple steps or multiple stages, and these steps or stages are not necessarily executed and completed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily to be carried out in sequence, but can be executed in turn or alternately with other steps or at least a portion of steps or stages in other steps.

[0145] Based on the same inventive concept, embodiments of the present application also provide a device for detecting ground resistance during high-voltage testing, for implementing the aforementioned method for detecting ground resistance during high-voltage testing. The solution provided by this device is similar to the solution described in the aforementioned method. Therefore, the specific limitations of one or more embodiments of the device for detecting ground resistance during high-voltage testing provided below can be found in the aforementioned definition of the method for detecting ground resistance during high-voltage testing, and will not be further elaborated here.

[0146] In an exemplary embodiment, Figure 7 As shown, a ground resistance detection device for high voltage testing is provided, comprising:

[0147] The data acquisition module 702 is used to inject a non-power frequency harmonic sine wave signal into the ground loop during the high voltage test and collect the response signal in the ground loop;

[0148] The data processing module 704 is used to perform multi-stage filtering on the collected response signal to obtain the effective amplitude and signal characteristics of the response signal;

[0149] A calculation module 706 is configured to calculate a ground resistance value of the ground loop based on the effective amplitude and signal characteristics of the response signal;

[0150] An analysis module 708 is configured to compare the ground resistance value with a preset resistance threshold and analyze whether there is a preset abnormal factor in the ground loop;

[0151] The control module 710 is used to trigger an alarm and control the high-voltage test equipment to cut off power when the ground resistance value exceeds a preset resistance threshold and / or there are preset abnormal factors in the ground loop.

[0152] In an exemplary embodiment, the data acquisition module 702 is specifically configured to generate a non-power frequency harmonic heterodyne sine wave signal having a frequency lower than a preset Hz through a non-contact magnetic coupling sensor; drive an excitation sensor to inject the non-power frequency harmonic heterodyne sine wave signal into a ground loop through magnetic coupling; and acquire a response signal generated in the ground loop based on the heterodyne sine wave signal.

[0153] In an exemplary embodiment, the data processing module 704 is specifically used to perform preliminary processing on the collected response signal, and the preliminary processing methods include programmable gain amplification, band-stop filtering, band-pass filtering and low-pass filtering; performing analog-to-digital conversion on the response signal after preliminary processing to obtain a response signal in a digital format; and performing software filtering on the response signal in the digital format to obtain the effective amplitude and signal characteristics of the response signal.

[0154] In an exemplary embodiment, the heterodyne sine wave signal includes at least two excitation signals of different frequencies; the calculation module 706 is specifically configured to measure the voltage and current values ​​of the at least two excitation signals of different frequencies based on the effective amplitudes and signal characteristics of the response signals corresponding to the at least two excitation signals of different frequencies; calculate the ground impedance values ​​at different frequencies based on the voltage and current values ​​of the at least two excitation signals of different frequencies; and calculate the ground resistance value of the ground loop based on the ground impedance values ​​at different frequencies.

[0155] In an exemplary embodiment, the analysis module 708 is specifically used to collect real-time operating data in the grounding loop, and analyze whether there are preset abnormal factors in the grounding loop based on the real-time operating data and historical operating data; the preset abnormal factors include grounding wire breakage, poor contact, loose grounding connection points, corrosion damage to the grounding body, and the presence of high impedance points in the grounding loop.

[0156] In an exemplary embodiment, the control module 710 is further configured to record error data and issue a pop-up alarm via the terminal when the ground resistance value exceeds a preset resistance threshold and / or there are preset abnormal factors in the ground loop.

[0157] Each module in the ground resistance detection device for high-voltage testing can be implemented in whole or in part through software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in hardware form, or can be stored in a memory in the computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0158] In an exemplary embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as shown in FIG. Figure 8 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O) and a communication interface. The processor, memory and input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The database of the computer device is used to store response signal data in the ground loop. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a ground resistance detection method in a high-voltage test is implemented.

[0159] Those skilled in the art will understand that Figure 8 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0160] In an exemplary embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and the processor implements the steps of the above method when executing the computer program.

[0161] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above method are implemented.

[0162] In one embodiment, a computer program product is provided, comprising a computer program, which implements the steps of the above method when executed by a processor.

[0163] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0164] Those skilled in the art will understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. In particular, any reference to memory, database, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The databases involved in the various embodiments provided herein may include at least one of a relational database and a non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the various embodiments provided herein may be, but are not limited to, general-purpose processors, central processing units (CPUs), graphics processing units (GPUs), digital signal processors (DSPs), programmable logic devices (PLDs), quantum computing-based data processing logic devices, artificial intelligence (AI) processors, and the like.

[0165] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0166] The above-described embodiments merely represent several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present application. It should be noted that a person of ordinary skill in the art may make various modifications and improvements without departing from the spirit of the present application, and these modifications and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A method for detecting ground resistance in high voltage testing, characterized in that: The method comprises: In high-voltage testing, a non-power frequency sinusoidal signal is injected into the ground loop, and the response signal in the ground loop is collected; Performing multi-stage filtering on the collected response signal to obtain the effective amplitude and signal characteristics of the response signal; Calculate the grounding resistance value of the grounding loop based on the effective amplitude and signal characteristics of the response signal; Comparing the grounding resistance value with a preset resistance threshold, and analyzing whether there is a preset abnormal factor in the grounding loop; When the grounding resistance value exceeds a preset resistance threshold and / or there is a preset abnormal factor in the grounding loop, an alarm is triggered and the high-voltage test equipment is controlled to be powered off.

2. The method according to claim 1, characterized in that The step of injecting a non-power frequency harmonic sine wave signal into the ground loop during the high voltage test and collecting a response signal in the ground loop includes: Generates a non-power frequency harmonic sine wave signal with a frequency lower than a preset Hz; Injecting a non-power frequency harmonic sinusoidal signal into the ground loop by magnetic coupling; Collect the response signal generated by the different-frequency sine wave signal in the ground loop.

3. The method according to claim 1, characterized in that The multi-stage filtering process is performed on the collected response signal to obtain the effective amplitude and signal characteristics of the response signal, including: Performing preliminary processing on the collected response signal, the preliminary processing methods include programmable gain amplification, band-stop filtering, band-pass filtering and low-pass filtering; Performing analog-to-digital conversion on the response signal after preliminary processing to obtain a response signal in digital format; The digital response signal is subjected to software filtering to obtain the effective amplitude and signal characteristics of the response signal.

4. The method according to claim 1, wherein The different-frequency sinusoidal wave signal includes at least two excitation signals with different frequencies; The calculating the grounding resistance value of the ground loop based on the effective amplitude and signal characteristics of the response signal includes: Based on the effective amplitudes and signal characteristics of the response signals corresponding to the at least two excitation signals of different frequencies, respectively measuring the voltage values ​​and current values ​​of the at least two excitation signals of different frequencies; Calculating ground impedance values ​​at different frequencies according to voltage values ​​and current values ​​of the at least two excitation signals of different frequencies; Calculate the grounding resistance of the grounding loop based on the grounding impedance values ​​at different frequencies.

5. The method according to claim 1, wherein The analysis of whether the ground loop has preset abnormal factors includes: Collect real-time operating data in the grounding loop, and analyze whether there are preset abnormal factors in the grounding loop based on the real-time operating data and historical operating data; the preset abnormal factors include grounding wire breakage, poor contact, loose grounding connection points, corroded grounding body damage and high impedance points in the grounding loop.

6. The method according to claim 1, wherein The method further comprises: When the grounding resistance value exceeds the preset resistance threshold and / or there are preset abnormal factors in the grounding loop, the error data is recorded and a pop-up alarm is issued through the terminal.

7. A ground resistance detection device in high voltage testing, characterized in that: The device comprises: The data acquisition module is used to inject a non-power frequency harmonic sine wave signal into the ground loop during high-voltage testing and collect the response signal in the ground loop; A data processing module is used to perform multi-stage filtering on the collected response signal to obtain the effective amplitude and signal characteristics of the response signal; a calculation module, configured to calculate a ground resistance value of the ground loop based on an effective amplitude and a signal characteristic of the response signal; An analysis module, configured to compare the ground resistance value with a preset resistance threshold and analyze whether there are preset abnormal factors in the ground loop; The control module is used to trigger an alarm and control the high-voltage test equipment to cut off power when the grounding resistance value exceeds a preset resistance threshold and / or there is a preset abnormal factor in the grounding loop.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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