Detection method and device of power transmission line and dual-channel traveling wave detection system

Abstract

The invention relates to a power transmission line detection method and device and a dual-channel traveling wave detection system. The method is used for the dual-channel traveling wave detection system. The method comprises the following steps: receiving traveling wave signals transmitted by detection units at two ends of a power transmission line; for each traveling wave signal, signal modulation processing is carried out on a reference signal provided by the dual-channel traveling wave detection system by using the traveling wave signal to obtain a composite signal, and the composite signal comprises traveling wave trigger information and complete waveform information of the traveling wave signal; signal detection is carried out on the power transmission line according to the composite signal, a detection result is obtained, the detection result is used for representing whether the power transmission line has a fault or not, and the fault position and the fault type are determined under the condition that the power transmission line has the fault. The method can improve the accuracy of the fault detection result of the power transmission line.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fault detection, in particular to a detection method and device for a power transmission line and a dual-channel traveling wave detection system. BACKGROUND

[0002] With the rapid development of the power system towards high voltage, large capacity and wide coverage, the operation reliability of the power transmission line, as the core carrier of power transmission, directly determines the stability of the whole network power supply, so higher requirements are put forward for the rapid and accurate diagnosis of the fault of the power transmission line. In the current field of power system fault diagnosis technology, for the detection of traveling wave fault of the power transmission line, the core devices usually used are Rogowski coils and optical fiber sensors.

[0003] However, in the actual deployment and operation process, the detection accuracy of the above-mentioned devices is prone to drift with the running time, and it is necessary to carry out offline or online calibration work regularly, which may also affect the continuity and timeliness of fault detection due to shutdown or data interruption during calibration.

[0004] Therefore, there is a problem of low accuracy of the fault detection result of the power transmission line in the related art. SUMMARY

[0005] Therefore, it is necessary to provide a detection method and device for a power transmission line and a dual-channel traveling wave detection system which can improve the accuracy of the fault detection result of the power transmission line.

[0006] In a first aspect, the present application provides a detection method for a power transmission line, which is used in a dual-channel traveling wave detection system. The method comprises:

[0007] receiving traveling wave signals transmitted by detection units at both ends of the power transmission line;

[0008] for each of the traveling wave signals, using the traveling wave signal to perform signal modulation processing on a reference signal provided by the dual-channel traveling wave detection system to obtain a composite signal, the composite signal comprising traveling wave trigger information and complete waveform information of the traveling wave signal;

[0009] performing signal detection on the power transmission line according to the composite signal to obtain a detection result, the detection result being used to represent whether the power transmission line has a fault, and in the case that the power transmission line has a fault, determining a fault position and a fault type.

[0010] In one of the embodiments, the performing signal detection on the power transmission line according to the composite signal to obtain a detection result comprises:

[0011] performing signal separation processing on the composite signal to obtain a trigger modulation component and a waveform modulation component;

[0012] According to the trigger modulation component and the waveform modulation component, signal detection is performed on the power transmission line to obtain a detection result.

[0013] In one embodiment, the signal detection performed on the power transmission line according to the trigger modulation component and the waveform modulation component to obtain a detection result includes:

[0014] The trigger modulation component is subjected to information extraction processing to obtain a synchronization timestamp of the traveling wave signal reaching the double-channel traveling wave detection system;

[0015] The waveform modulation component is subjected to spectrum analysis processing to obtain a waveform feature of the traveling wave signal;

[0016] According to the synchronization timestamp and the waveform feature, signal detection is performed on the power transmission line to obtain a detection result.

[0017] In one embodiment, the signal detection performed on the power transmission line according to the synchronization timestamp and the waveform feature to obtain a detection result includes:

[0018] According to the waveform feature and a preset feature threshold, it is determined whether the power transmission line has a fault;

[0019] In a case where it is determined that the power transmission line has a fault, the fault location is determined according to a time difference between the synchronization timestamps corresponding to the detection units and a propagation speed of the traveling wave signal, wherein the time difference is used to represent a time difference of the traveling wave signal propagating from the fault location to the detection units.

[0020] In one embodiment, the waveform feature includes a peak amplitude and a fundamental frequency, and the determination of whether the power transmission line has a fault according to the waveform feature and a preset feature threshold includes:

[0021] In a case where the peak amplitude is greater than or equal to a preset amplitude threshold and the fundamental frequency is within a preset frequency range, it is determined that the power transmission line has a fault.

[0022] In one embodiment, the waveform feature further includes a rising edge steepness, and the method further includes:

[0023] The rising edge steepness is compared with rising edge steepnesses corresponding to a plurality of fault types to obtain a plurality of comparison results, and the fault type is determined according to the plurality of comparison results.

[0024] In a second aspect, the application further provides a detection device for a power transmission line, which is used in a double-channel traveling wave detection system. The device includes:

[0025] The receiving module is used to receive traveling wave signals transmitted by the detection units at both ends of the transmission line;

[0026] The signal modulation module is used to perform signal modulation processing on the reference signal provided by the dual-channel traveling wave detection system for each traveling wave signal to obtain a composite signal, wherein the composite signal includes the traveling wave trigger information and the complete waveform information of the traveling wave signal;

[0027] The detection module is used to perform signal detection on the transmission line based on the composite signal, obtain detection results, and the detection results are used to characterize whether there is a fault in the transmission line, and to determine the fault location and fault type if there is a fault in the transmission line.

[0028] Thirdly, this application also provides a dual-channel traveling wave detection system. The dual-channel traveling wave detection system is used to perform the method described in any of the first aspects, and the dual-channel traveling wave detection system includes a detection unit, a signal modulation unit, and a signal detection unit;

[0029] The detection unit is used to receive traveling wave signals transmitted from both ends of the transmission line;

[0030] The signal modulation unit is used to perform signal modulation processing on the reference signal provided by the dual-channel traveling wave detection system using the traveling wave signal to obtain a composite signal.

[0031] The signal detection unit is used to perform signal detection on the transmission line based on the composite signal and obtain the detection result.

[0032] In one embodiment, the signal modulation unit includes an atomic probe;

[0033] The atomic probe includes two light-transmitting channel windows, each corresponding to a high-sensitivity triggering channel and a wide dynamic range characterization channel. The high-sensitivity triggering channel is used to convert the triggering information of the traveling wave signal into a trigger modulation component, and the wide dynamic range characterization channel is used to convert the complete waveform information of the traveling wave signal into a waveform modulation component.

[0034] In one embodiment, the signal modulation unit further includes a probe laser, a coupling laser, a first acousto-optic modulator, and a second acousto-optic modulator;

[0035] The detection laser is configured to emit detection light;

[0036] The coupled laser is configured to emit a coupled optical signal, and the coupled optical signal is split into two paths and input to the first acousto-optic modulator and the second acousto-optic modulator, respectively.

[0037] The first acousto-optic modulator is used to frequency modulate the first coupled optical signal at a first frequency to form the high-sensitivity trigger channel.

[0038] The second acousto-optic modulator is used to frequency modulate the second coupled optical signal according to the second frequency to form the wide dynamic range characterization channel.

[0039] In the aforementioned transmission line detection method, device, and dual-channel traveling wave detection system, the dual-channel traveling wave detection system first receives traveling wave signals transmitted from detection units at both ends of the transmission line. Then, for each traveling wave signal, the system modulates the reference signal provided by the dual-channel traveling wave detection system to obtain a composite signal. Subsequently, the system detects the transmission line based on the composite signal to obtain the detection result. The detection result is used to characterize whether a fault exists in the transmission line, and, if a fault exists, to determine the fault location and fault type. In this way, by combining the traveling wave signal with the system reference signal through modulation processing, the characteristic differences of the traveling wave signal are effectively amplified. Furthermore, since the composite signal includes the traveling wave trigger information and the complete waveform information of the traveling wave signal, it is possible to quickly capture the abrupt change characteristics of whether the traveling wave is arriving based on the traveling wave trigger information, and to accurately distinguish between faulty and non-faulty traveling waves based on the complete waveform information. This enables accurate determination of whether a transmission line is faulty, improving the accuracy of the detection results. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a diagram illustrating the application environment of a transmission line detection method in one embodiment.

[0042] Figure 2 This is a flowchart illustrating a method for detecting transmission lines in one embodiment;

[0043] Figure 3 This is a flowchart illustrating step 203 in one embodiment;

[0044] Figure 4 This is a flowchart illustrating step 302 in one embodiment;

[0045] Figure 5 This is a flowchart illustrating step 403 in one embodiment;

[0046] Figure 6This is a schematic diagram of a dual-channel traveling wave detection system in one embodiment;

[0047] Figure 7 This is a structural block diagram of a power transmission line detection device in one embodiment. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0049] The transmission line detection method provided in this application embodiment can be applied to, for example, Figure 1 The application environment shown. Among them, Figure 1 The system includes a transmission line 102, a detection unit 104, and a dual-channel traveling wave detection system 106. When the transmission line 102 generates a traveling wave signal, the detection unit 104 can detect and receive the signal. The dual-channel traveling wave detection system 106 first receives the traveling wave signals transmitted from the detection units at both ends of the transmission line. Then, for each traveling wave signal, it uses the traveling wave signal to modulate a reference signal provided by the dual-channel traveling wave detection system to obtain a composite signal. The composite signal includes the traveling wave trigger information and the complete waveform information. Then, it performs signal detection on the transmission line based on the composite signal to obtain a detection result. The detection result is used to characterize whether a fault exists in the transmission line, and, if a fault exists, to determine the fault location and fault type.

[0050] In one exemplary embodiment, such as Figure 2 As shown, a method for detecting transmission lines is provided, which can be applied to... Figure 1 Taking the dual-channel traveling wave detection system in the example, the following steps are included:

[0051] Step 201: Receive traveling wave signals transmitted by the detection units at both ends of the transmission line.

[0052] Transmission lines are the core carriers of electrical energy in a power system, responsible for transmitting the electricity generated by power plants to substations and distribution centers, ultimately supplying power for industrial production and residential use. When a transmission line experiences a fault, it generates a transient electromagnetic signal, known as a traveling wave signal. For example, a short circuit or lightning strike will cause this traveling wave signal to propagate along the line to both ends. Alternatively, even if the transmission line is not faulty, low-amplitude, stable, normal traveling wave signals may be generated during grid operations, such as circuit breaker closing / opening or transformer switching. Therefore, upon receiving a traveling wave signal, it is necessary to determine whether a fault exists in the transmission line based on the traveling wave signal.

[0053] The detection unit is a device deployed at both ends of the transmission line in a dual-channel traveling wave detection system, used to detect and receive traveling wave signals generated at both ends of the transmission line. Optionally, the two detection units can capture two traveling wave signals.

[0054] In this embodiment, when a traveling wave signal is generated by the transmission line, the detection units deployed at both ends of the transmission line can detect the two traveling wave signals propagating at both ends and transmit the two traveling wave signals to the dual-channel traveling wave detection system for signal detection.

[0055] Step 202: For each traveling wave signal, the reference signal provided by the dual-channel traveling wave detection system is modulated using the traveling wave signal to obtain a composite signal.

[0056] The composite signal includes the traveling wave triggering information and the complete waveform information of the traveling wave signal.

[0057] In this embodiment, the dual-channel traveling wave detection system performs the same detection process for two traveling wave signals. Therefore, the detection process of a traveling wave signal can be described exemplarily using a single traveling wave signal as an example.

[0058] It should be noted that the dual-channel traveling wave detection system includes an atomic vapor chamber and a laser control unit. The laser control unit emits probe light and two coupled beams to the atomic vapor chamber, forming two transparent windows. When the traveling wave signal passes through the atomic vapor chamber in the dual-channel traveling wave detection system, it affects the energy level states of the atoms, thereby changing the transparency of the light. This causes a change in the intensity of the probe light output from the two transparent windows. Therefore, based on the characteristics of the changed probe light signal, it is possible to determine whether the traveling wave signal is caused by a transmission line fault, and thus determine whether a fault exists in the transmission line and, if so, the type of fault.

[0059] The reference signal provided by the dual-channel traveling wave detection system is the basic optical signal of the double-transmittance window formed by the probe light and the two coupled lights. When the traveling wave signal modulates the reference signal, the resulting composite signal carries the traveling wave triggering information and the complete waveform information of the traveling wave signal.

[0060] Among them, the traveling wave triggering information is the abrupt change characteristic identifier when the traveling wave signal arrives at the detection unit, used to capture the arrival time of the traveling wave. The complete waveform information is all the physical characteristic data of the traveling wave from its generation to its propagation to the detection end, covering complete information in the time domain and frequency domain. For example, the complete waveform information can include peak / valley amplitude, pulse width, number of oscillations, rising / falling edge steepness, amplitude decay trajectory, etc. in the time domain, and fundamental frequency, harmonic component distribution, broadband spectrum range, amplitude proportion of each frequency component, etc. in the frequency domain.

[0061] In this embodiment, the dual-channel traveling wave detection system can modulate the reference signal under the action of the traveling wave signal to obtain a coincident signal carrying the traveling wave trigger information and the complete waveform information.

[0062] Step 203: Perform signal detection on the transmission line based on the composite signal to obtain the detection result.

[0063] The detection results are used to characterize whether there is a fault in the transmission line, and, if there is a fault in the transmission line, to determine the location and type of the fault.

[0064] Optionally, the test results may include whether the transmission line has a fault or not.

[0065] Here, "fault location" refers to the point in the transmission line where a fault occurs. "Fault type" refers to the type of fault that corresponds to the fault point; for example, fault types can include grounding faults, short-circuit faults, open-circuit faults, and combined faults.

[0066] In this embodiment, the dual-channel traveling wave detection system can determine the generation time of the traveling wave signal based on the traveling wave triggering information carried in the composite signal, and determine the time-domain and frequency-domain characteristics of the traveling wave signal based on the complete waveform information. Then, based on the preset time, time-domain and frequency-domain characteristics corresponding to the transmission line fault, it can determine whether the traveling wave signal is generated under the condition of a transmission line fault, thereby obtaining the signal detection result of the transmission line.

[0067] Optionally, if a fault exists in the transmission line, the fault location and fault type can be further determined based on the signal characteristic information of the composite signal.

[0068] In the aforementioned transmission line detection method, the dual-channel traveling wave detection system first receives traveling wave signals transmitted from the detection units at both ends of the transmission line. Then, for each traveling wave signal, the system modulates the reference signal provided by the dual-channel traveling wave detection system to obtain a composite signal. Subsequently, the system detects the transmission line based on the composite signal to obtain the detection result. The detection result is used to characterize whether there is a fault in the transmission line, and, if there is a fault, to determine the fault location and fault type. In this way, by combining the traveling wave signal with the system reference signal through modulation processing, the characteristic differences of the traveling wave signal are effectively amplified. Furthermore, since the composite signal includes the traveling wave trigger information and the complete waveform information of the traveling wave signal, it is possible to quickly capture the abrupt change characteristics of whether the traveling wave is arriving based on the traveling wave trigger information, and to accurately distinguish between faulty and non-faulty traveling waves based on the complete waveform information. This enables accurate determination of whether the transmission line is faulty, improving the accuracy of the detection results.

[0069] Furthermore, in the event of a fault in a transmission line, the system can quickly pinpoint the location of the fault and identify the type of fault, effectively improving the comprehensiveness and accuracy of transmission line fault detection, significantly shortening the fault investigation time, reducing the impact of faults on the operation of transmission lines, and providing a reliable guarantee for the safe and stable operation of the power grid.

[0070] In one exemplary embodiment, such as Figure 3 As shown, this embodiment relates to the process by which a dual-channel traveling wave detection system detects signals from a transmission line based on a composite signal and obtains the detection result. Step 203 includes:

[0071] Step 301: Perform signal separation processing on the composite signal to obtain the trigger modulation component and the waveform modulation component.

[0072] The signal separation process involves breaking down a composite signal containing trigger modulation components and waveform modulation components into two independent, clean signals. The core of this process is to achieve precise separation by utilizing the frequency difference between the two types of components.

[0073] Among them, the trigger modulation component is the signal component in the composite signal that carries the traveling wave triggering information of the traveling wave signal. It can be understood that the trigger modulation component presents a steep abrupt change + short pulse shape, and is extremely sensitive to the amplitude change and rising edge steepness of the traveling wave leading edge. It does not require a complete waveform, but only retains the key trigger point where the traveling wave arrives.

[0074] Among them, the waveform modulation component is the signal component in the composite signal that carries the full-dimensional physical characteristics of the traveling wave. It can be understood that the waveform modulation component presents the shape of a complete and continuous waveform, fully preserving the time domain (e.g., peak amplitude, pulse width, oscillation period, amplitude decay trajectory) and frequency domain (e.g., fundamental frequency, harmonic distribution, spectral energy ratio) characteristics of the traveling wave, with a wide dynamic range, and can adapt to traveling wave signals of different amplitudes.

[0075] It should be noted that the trigger modulation component and the waveform modulation component correspond to different preset characteristic frequencies, and their frequency ranges do not overlap. Therefore, different frequencies can be used to filter the composite signal to obtain the trigger modulation component and the waveform modulation component.

[0076] In this embodiment, the dual-channel traveling wave detection system can first perform photoelectric conversion on the composite signal, converting the composite signal from an optical signal to an electrical signal. Then, it can filter the composite signal in electrical form according to a first frequency to obtain a trigger modulation component, and filter the composite signal in electrical form according to a second frequency to obtain a waveform modulation component.

[0077] Step 302: Perform signal detection on the transmission line based on the trigger modulation component and the waveform modulation component to obtain the detection result.

[0078] In this embodiment, the dual-channel traveling wave detection system can obtain the near-end time T1 of the traveling wave signal received by the detection units at both ends of the transmission line based on the steep rising edge of the trigger modulation component, and the far-end time T2 of the traveling wave signal received by the detection units at both ends of the transmission line based on the steep falling edge of the trigger modulation component. Then, based on the near-end time T1 and the far-end time T2, the generation time of the traveling wave signal is determined. Next, the waveform modulation component is compared with the waveform modulation component of the fault traveling wave signal corresponding to the preset fault type. Then, based on the comparison result, it is determined whether it is a fault traveling wave, thereby obtaining the detection result.

[0079] In this embodiment, the dual-channel traveling wave detection system separates the composite signal to obtain the trigger modulation component and the waveform modulation component, thus obtaining independent and pure component signals. This ensures that the abrupt change characteristics of the trigger modulation component are not overwhelmed, while also ensuring that the full-dimensional characteristics of the waveform modulation component are completely preserved. Then, the transmission line is detected based on the trigger modulation component and the waveform modulation component, which can quickly and accurately determine whether there is a fault, thereby improving the efficiency and accuracy of the detection results.

[0080] In one exemplary embodiment, such as Figure 4 As shown, this embodiment relates to the process by which a dual-channel traveling wave detection system detects signals from a transmission line based on trigger modulation components and waveform modulation components, and obtains the detection results. Step 302 includes:

[0081] Step 401: Extract information from the trigger modulation component to obtain the synchronization timestamp of the traveling wave signal arriving at the dual-channel traveling wave detection system.

[0082] Among them, the synchronization timestamp is a unified reference time identifier generated after precise calibration when the traveling wave signal arrives at the two detection units of the dual-channel traveling wave detection system. In essence, it is a record of the arrival time of the traveling wave with synchronization calibration, providing a unified time reference at both ends for fault location.

[0083] In this embodiment, the dual-channel traveling wave detection system can extract the near-end time and far-end time of the traveling wave signal received by the detection unit from the trigger modulation component. Then, it calculates the absolute value of the difference between the near-end time and the far-end time, and then corrects the absolute value of the difference according to the preset standard time to obtain the synchronization timestamp.

[0084] Step 402: Perform spectral analysis on the waveform modulation component to obtain the waveform characteristics of the traveling wave signal.

[0085] Among them, the waveform characteristics of traveling wave signals are a set of key parameters that can reflect the essential properties of traveling waves. They are divided into two categories: time domain characteristics and frequency domain characteristics. They are the core basis for distinguishing between faulty and non-faulty traveling waves and identifying fault types.

[0086] In this embodiment, the dual-channel traveling wave detection system can use fast Fourier transform to convert the waveform modulation component from the time domain signal to the frequency domain signal. Then, the spectrum result is obtained based on the converted waveform modulation component. Subsequently, waveform features such as fundamental frequency, main frequency band range, and amplitude ratio of harmonic components are extracted from the spectrum result.

[0087] Step 403: Based on the synchronization timestamp and waveform characteristics, perform signal detection on the transmission line to obtain the detection results.

[0088] In this embodiment, the dual-channel traveling wave detection system can locate the generation position of the traveling wave signal based on the synchronization timestamp, then compare the waveform features with a preset fault feature database, determine the presence of a fault in the receiving and paying process based on the comparison results, and obtain the output detection results.

[0089] In this embodiment, the dual-channel traveling wave detection system extracts information from the trigger modulation component to obtain the synchronization timestamp of the traveling wave signal arriving at the dual-channel traveling wave detection system. It then performs spectral analysis on the waveform modulation component to obtain the waveform characteristics of the traveling wave signal. Based on the synchronization timestamp and waveform characteristics, the system detects the signal on the transmission line and obtains the detection results. Thus, precise synchronization timestamps ensure accurate fault location, and waveform characteristics improve fault identification accuracy. Ultimately, this achieves rapid fault detection, precise location pinpointing, and clear fault type identification, effectively reducing grid outage time, lowering maintenance costs, and significantly improving the safety and stability of transmission line operation.

[0090] In one exemplary embodiment, such as Figure 5 As shown, this embodiment relates to the process by which a dual-channel traveling wave detection system performs signal detection on a transmission line based on a synchronization timestamp and waveform characteristics, and obtains the detection result. Step 403 includes:

[0091] Step 501: Determine whether there is a fault in the transmission line based on the waveform characteristics and the preset characteristic threshold.

[0092] In this context, the characteristic threshold refers to a pre-defined quantization criterion for key waveform characteristics in the time and frequency domains of a traveling wave signal. It serves as the numerical boundary distinguishing between faulty and non-faulty traveling waves. The characteristic threshold can be considered the critical value for the occurrence of a fault; if the characteristic threshold is met, there is no fault; if the characteristic threshold is not met, a fault exists. For example, the characteristic threshold may include the peak amplitude threshold, pulse width threshold, zero-sequence component proportion threshold, and harmonic proportion threshold.

[0093] In this embodiment, the dual-channel traveling wave detection system can compare the waveform features with the corresponding feature thresholds in the preset feature thresholds one by one. Then, if the waveform features do not meet the feature thresholds, it can determine whether there is a fault in the transmission line, or if the waveform features meet the feature thresholds, it can determine that there is no fault in the transmission line.

[0094] Optionally, the waveform characteristics include peak amplitude and fundamental frequency. Based on the waveform characteristics and preset characteristic thresholds, it is determined whether a fault exists in the transmission line, including:

[0095] A fault is determined to exist in the transmission line if the peak amplitude is greater than or equal to the preset amplitude threshold and the fundamental frequency is within the preset frequency range.

[0096] Among them, the peak amplitude is the largest amplitude value in the time domain of the traveling wave signal, and the fundamental frequency is the core frequency in the frequency domain of the traveling wave signal where the energy is most concentrated.

[0097] In this embodiment, the dual-channel traveling wave detection system can determine whether the peak amplitude is greater than the amplitude threshold based on the difference between the peak amplitude and the amplitude threshold, and determine whether the fundamental frequency is within the frequency range based on the difference between the fundamental frequency and the upper and lower limits of the frequency range. Then, if the peak amplitude is greater than or equal to the preset amplitude threshold and the fundamental frequency is within the preset frequency range, it can determine that there is a fault in the transmission line.

[0098] As one possible implementation, the waveform feature also includes rising edge steepness, and the above method further includes:

[0099] The rising edge steepness is compared with the rising edge steepness corresponding to multiple preset fault types to obtain multiple comparison results, and the fault type is determined based on the multiple comparison results.

[0100] Among them, the rise steepness is the rate at which the traveling wave signal rises from the baseline to the peak value in the time domain waveform, reflecting how fast the signal amplitude rises.

[0101] It should be noted that the rising edge steepness of the traveling wave signal corresponding to different fault types exhibits a stable and distinguishable range. By comparing the measured steepness with the preset steepness range for each fault type, the corresponding fault type can be determined.

[0102] For example, a three-phase short-circuit fault will release a large amount of energy instantly, causing the amplitude of the traveling wave signal to rise rapidly and the rising edge to be steep; while the energy release of a ground fault or open circuit fault is gradual, the signal rises slowly and the steepness is low.

[0103] In this embodiment, the dual-channel traveling wave detection system can compare the rising edge steepness with the rising edge steepness corresponding to multiple fault types when a fault is determined in the transmission line. Based on the comparison results, it can determine which fault type the rising edge steepness of the traveling wave signal is consistent with, and then determine that fault type as the fault type corresponding to the traveling wave signal.

[0104] Step 502: If a fault is found in the transmission line, the fault location is determined based on the time difference between the synchronization timestamps of each detection unit and the propagation speed of the traveling wave signal.

[0105] The time difference is used to characterize the time difference between the travel wave signal propagating from the fault location to each detection unit.

[0106] In this embodiment, the dual-channel traveling wave detection system can first calculate the difference between the synchronization timestamps corresponding to each detection unit, then calculate the product between the difference and the propagation speed of the traveling wave signal, then determine the distance between the dual-channel traveling wave detection system and the location where the traveling wave signal is generated, and then determine the fault location based on the position coordinates of the dual-channel traveling wave detection system and the distance.

[0107] In this embodiment, the dual-channel traveling wave detection system can accurately distinguish between faulty and non-faulty traveling waves based on waveform characteristics and preset feature thresholds, avoiding misjudgments and omissions caused by single-dimensional judgment, ensuring the accuracy of fault identification, and thus improving the accuracy of determining whether there is a fault in the transmission line. Then, when it is determined that there is a fault in the transmission line, the fault location is determined based on the time difference between the synchronization timestamps corresponding to each detection unit and the propagation speed of the traveling wave signal. The time difference is used to characterize the time difference of the traveling wave signal from the fault location to each detection unit. In this way, by combining the traveling wave propagation speed and the synchronization time difference, the fault location time can be significantly shortened, thereby ensuring both the reliability of fault judgment and improving the efficiency of fault investigation.

[0108] In one exemplary embodiment, such as Figure 6 As shown, this embodiment also provides a dual-channel traveling wave detection system, which is used to perform the above-mentioned transmission line detection method. The dual-channel traveling wave detection system includes a detection unit, a signal modulation unit, and a signal detection unit.

[0109] The detection unit is used to receive traveling wave signals transmitted from both ends of the transmission line;

[0110] The signal modulation unit is used to perform signal modulation processing on the reference signal provided by the dual-channel traveling wave detection system using the traveling wave signal to obtain a composite signal;

[0111] The signal detection unit is used to detect signals in the transmission line based on composite signals and obtain the detection results.

[0112] The detection units can be deployed at both ends of the power transmission line.

[0113] As one possible implementation, the signal detection unit may include a photodetector for converting optical signals into electrical signals; a lock-in amplifier for extracting relevant modulation information based on a reference frequency; a high-speed data acquisition card for acquiring analog voltage signals and digitizing them, with a sampling rate of 1 GS / s; a field-programmable gate array (FPGA) for receiving the digital stream transmitted from the high-speed data acquisition card and performing real-time signal processing, and performing time synchronization and ultra-fast wavefront detection by receiving timestamp information from GPS or BeiDou; and an embedded main control computer for status monitoring, data storage, and remote communication of the dual-channel traveling wave detection system.

[0114] For example, lock-in amplifiers may include two, wherein the reference frequency of lock-in amplifier A may be set to f. mod1 Extract only those related to f mod1 The modulation information related to the reference signal is used to demodulate the signal from the high-sensitivity channel; the reference frequency of the lock-in amplifier B can be set to f. mod2 Only the modulation information associated with 1.5MHz is extracted, thereby demodulating the signal of the wide dynamic range channel.

[0115] Please continue to refer to this. Figure 6 The signal modulation unit includes an atomic probe; the atomic probe includes two light-transmitting channel windows, which correspond to a high-sensitivity trigger channel and a wide dynamic range characterization channel, respectively. The high-sensitivity trigger channel is used to convert the trigger information of the traveling wave signal into a trigger modulation component, and the wide dynamic range characterization channel is used to convert the complete waveform information of the traveling wave signal into a waveform modulation component.

[0116] The atomic probe, also known as an atomic vapor chamber, is an all-dielectric probe that connects to other components via optical fiber to achieve electrical isolation from high-voltage environments.

[0117] Please continue to refer to this. Figure 6 The signal modulation unit also includes a probe laser, a coupling laser, a first acousto-optic modulator, and a second acousto-optic modulator.

[0118] The probe laser is configured to emit probe light; the coupling laser is configured to emit coupling light signal, and the coupling light signal is divided into two paths and input to the first acousto-optic modulator and the second acousto-optic modulator respectively; the first acousto-optic modulator is used to frequency modulate the first coupled light signal according to a first frequency to form a high-sensitivity trigger channel; the second acousto-optic modulator is used to frequency modulate the second coupled light signal according to a second frequency to form a wide dynamic range characterization channel.

[0119] The probe light can pass through the atomic vapor chamber to lock the transition of an atom from the ground state to the excited state. For example, the wavelength of the probe light can be 852 nm.

[0120] The coupled optical signal is used to excite atoms from an excited state to a Rydberg state. For example, the wavelength of the coupled optical signal is about 510 nm.

[0121] In this embodiment, the dual-channel traveling wave detection system can tune the coupling light into two beams of first and second coupling light signals with different frequencies. The first coupling light signal can be used to excite the atom to a Rydberg state with a very high principal quantum number n (e.g., n>70), and the second coupling light signal can be used to excite the atom to a Rydberg state with a lower principal quantum number n (e.g., n≈40).

[0122] Understandably, before the coupled light enters the atomic vapor chamber, the first coupled light signal can be modulated at a first frequency by a first acousto-optic modulator, and the second coupled light signal can be modulated at a second frequency by a second acousto-optic modulator. Thus, under the influence of the modulated first and second coupled light signals, the atomic vapor chamber can form two transparent windows, corresponding to a high-sensitivity triggering channel and a wide dynamic range characterization channel, respectively.

[0123] In this way, when the dual-channel traveling wave detection system receives the traveling wave signal, the traveling wave signal adjusts the transparency of the corresponding light-transmitting window of the atomic vapor chamber, so that the signal output by the high-sensitivity trigger channel carries the trigger information of the traveling wave signal, i.e., the trigger modulation component, and the signal output by the wide dynamic range characterization channel carries the complete waveform information of the traveling wave signal, i.e., the waveform modulation component. Then, the trigger modulation component and the waveform modulation component are converted into electrical signals by the photodetector in the signal detection unit, and the trigger modulation component and the waveform modulation component are extracted by the lock-in amplifier in the signal detection unit. Next, the trigger modulation component and the waveform modulation component are acquired by the high-speed data acquisition card and transmitted to the field programmable gate array for signal processing. Then, based on the signal processing results, it is determined whether the traveling wave signal is a fault signal, thereby determining whether there is a fault in the transmission line, and if a fault exists, fault location and fault type are determined.

[0124] In this embodiment, a traveling wave signal is detected by a detection unit. Then, a modulation unit modulates the reference signal provided by the dual-channel traveling wave detection system using the traveling wave signal to obtain a composite signal. Subsequently, a signal detection unit performs signal detection on the transmission line based on the composite signal to obtain the detection result. In this way, the detection unit accurately captures the traveling wave signal of the transmission line, providing a real data source for fault detection and avoiding detection blind spots caused by signal omissions. The modulation unit fuses the traveling wave signal and the reference signal to generate a composite signal, which not only retains the core fault characteristics of the traveling wave signal, but also enhances the signal's anti-interference capability through the reference signal, reducing the impact of electromagnetic and environmental interference on detection accuracy. The signal detection unit then completes integrated detection based on the composite signal, eliminating the need for additional signal conversion or amplification modules, simplifying the system detection process and improving signal processing efficiency. The entire process, from signal acquisition and modulation to detection, forms a closed loop, ensuring the integrity of fault characteristics and signal stability, simplifying the system structure, and improving the detection response speed. Ultimately, this achieves rapid and accurate identification and location of transmission line faults, shortens fault downtime, reduces operation and maintenance costs, and enhances the safety and reliability of power grid operation.

[0125] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0126] Based on the same inventive concept, this application also provides a transmission line detection device for implementing the above-described transmission line detection method. The solution provided by this device is similar to the implementation described in the above method; therefore, the specific limitations of one or more transmission line detection device embodiments provided below can be found in the limitations of the transmission line detection method described above, and will not be repeated here.

[0127] In one embodiment, such as Figure 7 As shown, a detection device for transmission lines is provided for a dual-channel traveling wave detection system, comprising: a receiving module 701, a signal modulation module 702, and a detection module 703, wherein:

[0128] The receiving module 701 is used to receive traveling wave signals transmitted by the detection units at both ends of the transmission line;

[0129] The signal modulation module 702 is used to perform signal modulation processing on the reference signal provided by the dual-channel traveling wave detection system for each traveling wave signal to obtain a composite signal. The composite signal includes the traveling wave trigger information and the complete waveform information of the traveling wave signal.

[0130] The detection module 703 is used to perform signal detection on the transmission line based on the composite signal, obtain the detection result, and use the detection result to characterize whether there is a fault in the transmission line, and determine the fault location and fault type when there is a fault in the transmission line.

[0131] The transmission line detection device provided in this embodiment can execute the above method embodiment, and its implementation principle and technical effect are similar, so it will not be described again here.

[0132] In one embodiment, the detection module 703 includes:

[0133] The signal separation unit is used to perform signal separation processing on the composite signal to obtain the trigger modulation component and the waveform modulation component;

[0134] The detection unit is used to detect signals in the transmission line based on the trigger modulation component and the waveform modulation component, and obtain the detection results.

[0135] The transmission line detection device provided in this embodiment can execute the above method embodiment, and its implementation principle and technical effect are similar, so it will not be described again here.

[0136] In one embodiment, the detection unit described above is specifically used for:

[0137] Information extraction processing is performed on the trigger modulation component to obtain the synchronization timestamp of the traveling wave signal arriving at the dual-channel traveling wave detection system;

[0138] The waveform characteristics of the traveling wave signal are obtained by performing spectral analysis on the waveform modulation components.

[0139] Based on the synchronization timestamp and waveform characteristics, signal detection is performed on the transmission line to obtain the detection results.

[0140] The transmission line detection device provided in this embodiment can execute the above method embodiment, and its implementation principle and technical effect are similar, so it will not be described again here.

[0141] In one embodiment, the detection unit described above is specifically used for:

[0142] Based on waveform characteristics and preset characteristic thresholds, determine whether there is a fault in the transmission line;

[0143] When a fault is determined in the transmission line, the fault location is determined based on the time difference between the synchronization timestamps of each detection unit and the propagation speed of the traveling wave signal; wherein, the time difference is used to characterize the time difference for the traveling wave signal to propagate from the fault location to each detection unit. The transmission line detection device provided in this embodiment can execute the above method embodiment, and its implementation principle and technical effects are similar, and will not be repeated here.

[0144] In one embodiment, the waveform features include peak amplitude and fundamental frequency, and the aforementioned detection unit is specifically used for:

[0145] A fault is determined to exist in the transmission line if the peak amplitude is greater than or equal to the preset amplitude threshold and the fundamental frequency is within the preset frequency range.

[0146] The transmission line detection device provided in this embodiment can execute the above method embodiment, and its implementation principle and technical effect are similar, so it will not be described again here.

[0147] In one embodiment, the waveform feature further includes a rising edge steepness, and the above-described device further includes:

[0148] The determination module is used to compare the rising edge steepness with the rising edge steepness corresponding to multiple preset fault types, obtain multiple comparison results, and determine the fault type based on the multiple comparison results.

[0149] The transmission line detection device provided in this embodiment can execute the above method embodiment, and its implementation principle and technical effect are similar, so it will not be described again here.

[0150] Each module in the aforementioned transmission line detection device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the computer device's memory as software, so that the processor can call and execute the corresponding operations of each module.

[0151] 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, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties.

[0152] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile 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 many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0153] The technical features of the above embodiments can be combined in any way. For the sake of brevity, 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 specification.

[0154] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A method of detecting a power transmission line, characterized by, The method for a double-channel traveling wave detection system comprises: receiving traveling wave signals transmitted by detection units at both ends of a power transmission line; for each of the traveling wave signals, performing signal modulation processing on a reference signal provided by the double-channel traveling wave detection system using the traveling wave signal to obtain a composite signal, the composite signal comprising traveling wave trigger information and complete waveform information of the traveling wave signal; performing signal detection on the power transmission line according to the composite signal to obtain a detection result, the detection result being used to represent whether a fault exists in the power transmission line and, if a fault exists in the power transmission line, determining a fault location and a fault type.

2. The method of claim 1, wherein, The signal detection on the power transmission line according to the composite signal to obtain a detection result comprises: performing signal separation processing on the composite signal to obtain a trigger modulation component and a waveform modulation component; performing signal detection on the power transmission line according to the trigger modulation component and the waveform modulation component to obtain a detection result.

3. The method of claim 2, wherein, The signal detection on the power transmission line according to the trigger modulation component and the waveform modulation component to obtain a detection result comprises: performing information extraction processing on the trigger modulation component to obtain a synchronization time stamp of the traveling wave signal reaching the double-channel traveling wave detection system; performing frequency spectrum analysis processing on the waveform modulation component to obtain waveform characteristics of the traveling wave signal; performing signal detection on the power transmission line according to the synchronization time stamp and the waveform characteristics to obtain a detection result.

4. The method of claim 3, wherein, The signal detection on the power transmission line according to the synchronization time stamp and the waveform characteristics to obtain a detection result comprises: determining whether a fault exists in the power transmission line according to the waveform characteristics and a preset characteristic threshold value; if it is determined that a fault exists in the power transmission line, determining the fault location according to a time difference between the synchronization time stamps corresponding to the detection units and a propagation speed of the traveling wave signal; wherein the time difference is used to represent a time difference of the traveling wave signal propagating from the fault location to the detection units.

5. The method of claim 4, wherein, The waveform characteristics comprise a peak amplitude and a fundamental frequency, and the determination of whether a fault exists in the power transmission line according to the waveform characteristics and a preset characteristic threshold value comprises: if the peak amplitude is greater than or equal to a preset amplitude threshold value and the fundamental frequency is within a preset frequency range, it is determined that a fault exists in the power transmission line.

6. The method of claim 4, wherein, The waveform characteristics further comprise a rising edge steepness, and the method further comprises: comparing the rising edge steepness with rising edge steepnesses corresponding to a plurality of fault types to obtain a plurality of comparison results, and determining the fault type according to the plurality of comparison results.

7. A detection device for a power transmission line, characterized in that The device for a double-channel traveling wave detection system comprises: a receiving module configured to receive traveling wave signals transmitted by detection units at both ends of a power transmission line; a signal modulation module configured to, for each of the traveling wave signals, perform signal modulation processing on a reference signal provided by the double-channel traveling wave detection system using the traveling wave signal to obtain a composite signal, the composite signal comprising traveling wave trigger information and complete waveform information of the traveling wave signal; a signal detection module configured to perform signal detection on the power transmission line according to the composite signal to obtain a detection result, the detection result being used to represent whether a fault exists in the power transmission line and, if a fault exists in the power transmission line, determining a fault location and a fault type. The detection module is configured to perform signal detection on the power transmission line according to the composite signal to obtain a detection result, wherein the detection result is used to represent whether the power transmission line has a fault, and in the case that the power transmission line has a fault, the fault position and the fault type are determined.

8. A dual-channel traveling wave detection system, characterized by, The double-channel traveling wave detection system is used to perform the method of claims 1-6, and the double-channel traveling wave detection system comprises a detection unit, a signal modulation unit and a signal detection unit. The detection unit is configured to receive traveling wave signals transmitted at both ends of the power transmission line. The signal modulation unit is configured to perform signal modulation processing on a reference signal provided by the double-channel traveling wave detection system by using the traveling wave signals to obtain a composite signal. The signal detection unit is configured to perform signal detection on the power transmission line according to the composite signal to obtain a detection result.

9. The dual-channel traveling wave detection system of claim 8, wherein, The signal modulation unit comprises an atomic probe. The atomic probe comprises two light transmission channel windows, and the two light transmission channel windows correspond to a high-sensitivity trigger channel and a wide dynamic range representation channel, respectively.

10. The dual-channel traveling wave detection system of claim 9, wherein, The high-sensitivity trigger channel is configured to convert trigger information of the traveling wave signals into trigger modulation components. The wide dynamic range representation channel is configured to convert complete waveform information of the traveling wave signals into waveform modulation components. The signal modulation unit further comprises a detection laser, a coupling laser, a first acousto-optic modulator and a second acousto-optic modulator. The detection laser is configured to emit detection light. The coupling laser is configured to emit a coupling light signal, and the coupling light signal is divided into two paths and input into the first acousto-optic modulator and the second acousto-optic modulator, respectively. The first acousto-optic modulator is configured to perform frequency modulation on the first path of the coupling light signal according to a first frequency to form the high-sensitivity trigger channel. The second acousto-optic modulator is configured to perform frequency modulation on the second path of the coupling light signal according to a second frequency to form the wide dynamic range representation channel.

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