Transformer zero line live fault point judgment detector

Abstract

The application provides a transformer zero line live fault point judgment detector, and relates to the field of power fault diagnosis equipment. The transformer zero line live fault point judgment detector comprises a perception layer, an analysis layer and an interaction layer three-layer design architecture, the perception layer captures signals through a wide frequency electromagnetic induction array, the perception layer is composed of an electromagnetic induction array hardware and a frequency coverage module, and high-sensitive electromagnetic capture is realized by cooperating with a spatial arrangement technology; the hardware of the electromagnetic induction array is 8 groups of nanocrystalline alloy induction coils which are distributed in a ring shape, and each group of coils is connected in series with a 0.1 mu F high-frequency capacitor. The application realizes accurate anti-interference through topology identification and feature matching, the positioning speed is improved by 300 times, the detection efficiency is greatly improved, the power loss is reduced, the economic benefit is significantly improved, and the risk of manually contacting the live line is completely eliminated.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of power fault diagnosis equipment, in particular to a transformer zero line live fault point judgment detector. BACKGROUND

[0002] The transformer electric quantity parameter detector is a special instrument for detecting electric quantity parameters of power transformers. In a complex power grid environment (such as a multi-branch line and a high-load transformer station), the traditional equipment cannot distinguish between main line and branch line faults, often resulting in "positioning drift" and expanding the scope of troubleshooting by 3-5 times. Manual recording of fault information is prone to omissions or errors, and cannot be linked with the power grid management system to form a closed loop of fault analysis. The repeated fault rate is high (about 20% of the fault points will occur again within 3 months), and in humid, dusty or strong electromagnetic radiation areas (such as around a transformer substation), the sensitivity of traditional detection tools drops sharply, with a detection success rate of less than 60%. Multiple detection is required, and after a fault occurs, a professional team needs to be dispatched to the scene with multiple sets of equipment, which takes an average of 1.5 hours from receiving the alarm to starting detection, seriously affecting the repair time.

[0003] Therefore, the present application provides a transformer zero line live fault point judgment detector, which effectively solves the above problems. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a transformer zero line live fault point judgment detector. The present application is a non-contact handheld detection instrument that realizes precise anti-interference through topology identification and feature matching, improves positioning speed by 300 times, greatly improves detection efficiency, reduces power loss, significantly improves economic benefits, completely eliminates the risk of manual contact with live lines, improves the safety of workers, has safety value, and has a cost of only 1 / 3 of imported equipment, is suitable for popularization in basic power supply stations, and has popularization value and is suitable for comprehensive popularization.

[0005] To achieve the above purpose, the present application realizes the following technical solutions:

[0006] A transformer zero line live fault point judgment detector, the detector includes a perception layer, an analysis layer and an interaction layer three-layer design architecture, the perception layer captures signals by setting a wideband electromagnetic induction array, the perception layer is composed of an electromagnetic induction array hardware and a frequency coverage module, and high-sensitivity electromagnetic capture is realized by cooperating with a spatial arrangement technology, the electromagnetic induction array hardware is an 8-group nanocrystalline alloy induction coil distributed in a ring shape, each group of coils is connected in series with a 0.1 mu F high-frequency capacitor, and the outside is wrapped with a 0.2 mm permalloy magnetic shielding layer, the frequency coverage module realizes distortionless collection of 50Hz-10kHz full-band signals through the turn number gradient design of 200 turns of the inner circle and 100 turns of the outer circle, and the induction coil is arranged in a 360° ring shape, which ensures that the signal attenuation is less than or equal to 10% during detection at any angle.

[0007] The analysis layer adopts anti-resistive phase contrast and traveling wave ranging dual-mode positioning engine, and the analysis layer comprises an anti-resistive phase contrast module, a traveling wave ranging module and an algorithm fusion module, the anti-resistive phase contrast module digitizes analog signals through a 16-bit AD converter and eliminates fundamental wave interference through a 50Hz notch filter, the traveling wave ranging module is used for transient signal capture, and a 1kHz-10kHz traveling wave signal generated at the moment of fault is captured, and the algorithm fusion module dynamically adjusts the weight based on real-time electromagnetic interference intensity;

[0008] The interaction layer realizes three-dimensional channel output of screen display, alarm system and AR, and comprises an audible and visual alarm system, a display module and an AR real scene navigation module, the display module adopts a 1.5-inch touch screen to display the fault distance in real time, the audible and visual alarm system is divided into three levels of pre-warning level, fault level and emergency level, the AR real scene navigation module is wirelessly connected with a mobile phone APP through Bluetooth, the APP calls a camera to scan the surrounding environment of the line, and a fault point direction is marked with a red arrow in a real scene picture in combination with GPS positioning.

[0009] Further, the anti-resistive phase contrast module of the analysis layer calculates the phase based on fast Fourier transform to extract the 50Hz fundamental wave phase, calculate the phase difference between the zero line and the ground line, and the calculation method is that the zero line voltage signal is , the ground line voltage signal is , and both are continuous alternating signals changing with time, the continuous signals are sampled at a sampling frequency to obtain a discrete time sequence:

[0010] ;

[0011] wherein is a sampling period, is the total number of sampling points, and the time domain signal is converted into a frequency domain complex sequence through FFT transformation:

[0012]

[0013]

[0014] wherein, is a frequency index, is an imaginary unit, is a frequency domain complex, and finally, 50Hz basic wave frequency positioning is performed, the frequency resolution of FFT is , the actual frequency corresponding to the first frequency point is:

[0015]

[0016] find the frequency point index closest to 50Hz :

[0017]

[0018] In the engineering, usually take , , , , the corresponding frequency , when the phase difference deviates from the threshold value for 3 consecutive periods, it is marked as a suspicious area with positioning error ≤1 meter.

[0019] Further, the traveling wave distance measurement module of the analysis layer utilizes the propagation characteristics of the transient traveling wave generated by the fault point in the process of transient signal capture, the propagation speed of the traveling wave in the conductor is , the time of the incident wave head reaching the detector is , the time of the reflected wave head reaching the detector is , and the time difference is:

[0020] ;

[0021] Since the total distance of the traveling wave from the detector to the fault point and back to the detector is , the fault distance L is:

[0022] ;

[0023] The distance error is determined by the time difference measurement error and the wave speed error , which needs to be quantified and controlled by the formula:

[0024] ;

[0025] The error of calculating the fault distance by the time difference of the traveling wave head arrival time is ≤0.3 meters.

[0026] Further, the algorithm fusion module of the analysis layer dynamically adjusts the weight of the anti-resistance phase contrast and the traveling wave distance measurement based on the real-time electromagnetic interference intensity, detects the real-time interference intensity by the noise sensor, and uses to represent:

[0027] ;

[0028] Where is the minimum interference threshold, is the maximum interference threshold, , 0 represents no interference, 1 represents extremely strong interference, the weight of the anti-resistance phase contrast is , the weight of the traveling wave distance measurement is , and it needs to satisfy:

[0029] :

[0030]

[0031]

[0032] By the above weight formula And The final fault distance Is the weighted sum of the two positioning results:

[0033] ;

[0034] Wherein The fault distance calculated by the anti-phase contrast, The fault distance calculated by the traveling wave distance measurement.

[0035] Further, the interactive layer realizes human-computer interaction design, the AR real scene navigation module is scanned automatically after self-checking, the display module supports sunlight visible brightness adjustment, the fault distance is displayed in real time to 0.1 meters, and the screen response time is <100ms.

[0036] Further, the sound and light alarm system of the interactive layer, the limiting range of the early warning level is >15V, the warning performance of the early warning level is yellow light constant light indicating approaching the fault area, the limiting range of the fault level is >36V, the warning performance of the fault level is red light flashing and buzzer ringing, indicating that the fault point is near, the limiting range of the emergency level is >50V, the warning performance of the emergency level is red light constant light, buzzer continuous ringing, and alarm information is sent to the background at the same time.

[0037] The application provides a transformer zero line live fault point judgment detector.

[0038] 1.The application provides a transformer zero line live fault point judgment detector, compared with the traditional fault point judgment detector, the application is a non-contact handheld detector, which realizes accurate anti-interference through topology identification and feature matching, improves the positioning speed by 300 times, greatly improves the detection efficiency, reduces the power loss, significantly improves the economic benefit, completely eliminates the risk of manual contact with live lines, improves the work safety of workers, has safety value, the cost is only 1 / 3 of imported equipment, is suitable for popularization in basic power supply stations, has popularization value and is suitable for popularization.

[0039] 2. This invention provides a transformer neutral wire live fault point detection instrument, which is the first to use a non-contact scanning and AR visualization neutral wire fault detection mode. It solves the problem of misjudgment in complex environments through a dual-mode positioning algorithm. In addition, it is designed with zero learning cost for the large differences in the operation ability of grassroots electricians, realizing a user-friendly operation design, reducing the threshold for use, and breaking through the industry bottleneck of traditional equipment where cost and accuracy cannot be achieved at the same time. Through image recognition technology and matching with a GIS database, it can still locate in areas without GPS signal. Attached Figure Description

[0040] Fig. 1 This is a functional block diagram of the detector of the present invention;

[0041] Fig. 2 This is a system architecture diagram of the detector of the present invention. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Example 1:

[0044] like Figs. 1-2 As shown, this embodiment of the invention provides a transformer neutral wire live fault point detection instrument. The instrument includes a three-layer design architecture: a sensing layer, an analysis layer, and an interaction layer. The sensing layer captures signals by setting up a wideband electromagnetic induction array. The sensing layer consists of electromagnetic induction array hardware and a frequency coverage module. It uses spatial arrangement technology to achieve high-sensitivity electromagnetic capture. The electromagnetic induction array hardware consists of 8 groups of nanocrystalline alloy induction coils arranged in a ring. Each group of coils is connected in series with a 0.1μF high-frequency capacitor and is wrapped with a 0.2mm permalloy magnetic shielding layer. The frequency coverage module achieves distortion-free acquisition of signals in the 50Hz-10kHz full frequency band through a coil turn gradient design with 200 turns in the inner ring and 100 turns in the outer ring. The induction coils are arranged in a 360° ring, ensuring that the signal attenuation is ≤10% when detecting at any angle.

[0045] The analysis layer employs a dual-mode positioning engine of impedance phase comparison and traveling wave ranging. The analysis layer includes an impedance phase ratio module, a traveling wave ranging module, and an algorithm fusion module. The impedance phase ratio module uses a 16-bit AD converter to digitize the analog signal and then uses a 50Hz notch filter to eliminate fundamental interference. The traveling wave ranging module is used for transient signal capture, capturing 1kHz-10kHz traveling wave signals generated at the moment of fault. The algorithm fusion module dynamically adjusts the weights based on the real-time electromagnetic interference intensity.

[0046] The interaction layer enables three-dimensional channel output of screen display, alarm system and AR, including sound and light alarm system, display module and AR real scene navigation module. The display module uses a 1.5-inch touch screen to display the fault distance in real time. The sound and light alarm system is divided into three levels: warning level, fault level and emergency level. The AR real scene navigation module is wirelessly connected to the mobile APP via Bluetooth. The APP calls the camera to scan the surrounding environment of the line and marks the direction of the fault point with red arrows in the real scene picture with GPS positioning.

[0047] Example 2:

[0048] like Figs. 1-2 As shown, this embodiment of the invention provides a transformer neutral wire live fault point detection instrument. The anti-phase comparison module of the analysis layer extracts the 50Hz fundamental phase based on fast Fourier transform through phase calculation, and calculates the phase difference between the neutral wire and the ground wire. The calculation method is as follows: assuming the neutral wire voltage signal is... The ground voltage signal is Both are continuous AC signals that vary with time. The continuous signals are sampled at a frequency... Sampling is performed to obtain discrete time series:

[0049] ;

[0050] in The sampling period is The total number of sampling points is then used to convert the time-domain signal into a frequency-domain complex sequence using FFT transformation.

[0051]

[0052]

[0053] in, For frequency index, The imaginary unit, For the frequency domain complex numbers, the final frequency of the 50Hz fundamental wave is determined, and the frequency resolution of the FFT is [value missing]. , No. The actual frequencies corresponding to each frequency point are:

[0054]

[0055] Find the frequency index closest to 50Hz :

[0056]

[0057] In engineering, the following are usually taken , ,but , corresponding frequency When the phase difference deviates from the threshold value for 3 consecutive periods, it is marked as a suspicious area positioning error ≤1 meter;

[0058] The traveling wave distance measurement module of the analysis layer utilizes the propagation characteristics of the transient traveling wave generated by the fault point in the process of transient signal capture. The propagation speed of the traveling wave in the conductor is , the time when the incident wave front reaches the detector is , the time when the reflected wave front reaches the detector is , and the time difference is:

[0059] ;

[0060] Since the total distance of the traveling wave from the detector to the fault point and back to the detector is , the fault distance L is:

[0061] ;

[0062] Distance error is determined by the time difference measurement error and the wave speed error , which needs to be quantified and controlled by the formula:

[0063] ;

[0064] The fault distance is calculated by the time difference Δt of the traveling wave front arrival, so that the error is ≤0.3 meters;

[0065] The algorithm fusion module of the analysis layer dynamically adjusts the weight of the anti-resistance phase contrast and the traveling wave distance measurement based on the real-time electromagnetic interference intensity. The real-time interference intensity is detected by the noise sensor, and is represented by ;

[0066] ;

[0067] Among them is the minimum interference threshold, is the maximum interference threshold, , 0 represents no interference, 1 represents extremely strong interference, the weight of the anti-resistance phase contrast is , the weight of the traveling wave distance measurement is , and needs to meet:

[0068] :

[0069]

[0070]

[0071] The weight formula is obtained by the above And The final fault distance Is the weighted sum of the two positioning results:

[0072] ;

[0073] Wherein Is the fault distance calculated by the anti-phase phase contrast, Is the fault distance calculated by the traveling wave distance measurement;

[0074] The interactive layer realizes the man-machine interaction design, the AR real scene navigation module is scanned automatically after self-checking of starting, the display module supports the visible brightness adjustment under sunlight, the real-time display fault distance is accurate to 0.1 meters, the screen response time is <100ms, the sound and light alarm system of the interactive layer, the limit range of the early warning level is >15V, the warning performance of the early warning level is yellow light constant brightness prompt approaching the fault area, the limit range of the fault level is >36V, the warning performance of the fault level is red light flashing and buzzer ringing, prompt near the fault point, the limit range of the emergency level is >50V, the warning performance of the emergency level is red light constant brightness, buzzer continuous ringing, and sends alarm information to the background.

[0075] Working principle: the transformer zero line live fault point judgment detector is a non-contact handheld detector, which realizes rapid positioning of the fault point through three steps:

[0076] Step 1: electromagnetic signal capture: in 0.3-0.5m distance, abnormal current of zero line is inducted;

[0077] Step 2: intelligent positioning: analyze the fault position combining the line impedance characteristics and signal propagation characteristics;

[0078] Step 3: visual alarm: display the fault distance on the screen, and mark the positioning point by AR technology.

[0079] In this paper, the following points need attention:

[0080] 1. The drawings of the embodiments of the present disclosure only involve the structures involved in the embodiments of the present disclosure, and other structures can refer to the general design.

[0081] 2. In the case of no conflict, the embodiments of the present disclosure and the features in the embodiments can be combined to obtain new embodiments.

[0082] While embodiments of the application have been shown and described, it is to be understood that the application is not limited to the details of the embodiments described, since various modifications can be made by those skilled in the art, without departing from the spirit and scope of the application, which are defined by the appended claims and their equivalents. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present application, without creative work, are within the scope of the present application.

Claims

1. A transformer neutral wire live fault point detection instrument, characterized in that: The detector includes a three-layer design architecture of a sensing layer, an analysis layer and an interaction layer, the sensing layer captures signals by setting a wideband electromagnetic induction array, the sensing layer is composed of an electromagnetic induction array hardware and a frequency coverage module, and high-sensitivity electromagnetic capture is realized by cooperating with a spatial arrangement technology, the electromagnetic induction array hardware is 8 groups of nanocrystalline alloy induction coils in a ring-shaped distribution, each group of coils is connected in series with a 0.1 mu F high-frequency capacitor, and the outside is wrapped with a 0.2 mm permalloy magnetic shielding layer, the frequency coverage module realizes distortionless signal collection in a 50Hz-10kHz full-band by a coil turn number gradient design of 200 turns in the inner circle and 100 turns in the outer circle, and the induction coils are arranged in a 360° ring, which ensures that the signal attenuation is less than or equal to 10% when detecting at any angle; The analysis layer adopts a dual-mode positioning engine of anti-resistance phase contrast and traveling wave distance measurement, the analysis layer includes an anti-resistance phase contrast module, a traveling wave distance measurement module and an algorithm fusion module, the anti-resistance phase contrast module digitizes analog signals by using a 16-bit AD converter and then eliminates fundamental wave interference by using a 50Hz notch filter, the traveling wave distance measurement module is used for transient signal capture, and 1kHz-10kHz traveling wave signals generated at the moment of failure are captured, and the algorithm fusion module dynamically adjusts the weight based on real-time electromagnetic interference intensity; The interaction layer realizes three-dimensional channel output of screen display, alarm system and AR, including an audible and visual alarm system, a display module and an AR real scene navigation module, the display module uses a 1.5 inch touch screen to display the fault distance in real time, the audible and visual alarm system is divided into three levels of pre-warning level, fault level and emergency level, the AR real scene navigation module is wirelessly connected with a mobile phone APP through Bluetooth, the APP calls the camera to scan the surrounding environment of the line, and the GPS positioning marks the direction of the fault point in the real scene picture with a red arrow.

2. The transformer neutral live fault point judgment detector according to claim 1, characterized in that: The anti-phase phase ratio module of the analysis layer calculates the phase of the 50Hz fundamental wave based on fast Fourier transform, calculates the phase difference between the zero line and the ground line, and the calculation method is that the zero line voltage signal is , the ground line voltage signal is , and both are continuous alternating signals changing with time. The continuous signals are sampled at a sampling frequency to obtain discrete time sequences: ； wherein is a sampling period, is the total number of sampling points, and the time-domain signal is converted into a frequency-domain complex sequence by an FFT transform. wherein, is a frequency index, is an imaginary unit, is a frequency domain complex, finally 50Hz base wave frequency positioning, the frequency resolution of FFT is , the actual frequency corresponding to the th frequency point is: Find the frequency bin index closest to 50Hz : Among them, the engineering usually takes 、 Then , The corresponding frequency When the phase difference deviates from the threshold value for 3 consecutive periods > 3, it is marked as a suspicious area positioning error ≤ 1 meter.

3. The transformer neutral live fault point judgment detector according to claim 1, characterized in that: The traveling wave distance measurement module of the analysis layer utilizes the propagation characteristics of the transient traveling wave generated by the fault point in the process of transient signal capture, the propagation speed of the traveling wave in the conductor is , the time of the incident wave head reaching the detector is , the time of the reflected wave head reaching the detector is , and the time difference is: ； Since the total distance of the travelling wave from the detector to the fault point and back to the detector is Thus the fault distance L is ； Distance error Measured by time difference error And wave velocity error Together determine, need to quantify and control by formula: ； The fault distance is calculated by the traveling wave head time difference Delta t, so that the error is less than or equal to 0.3 meters.

4. The transformer neutral live fault point judgment detector according to claim 1, characterized in that: The algorithm fusion module of the analysis layer dynamically adjusts the weight of the anti-phase phase contrast and the traveling wave distance measurement based on the real-time electromagnetic interference intensity, detects the real-time interference intensity by using a noise sensor, and uses indicates: ； wherein is a minimum interference threshold, is a maximum interference threshold, 0 means no interference, 1 means very strong interference, the weight of the anti-phase phase contrast is the weight of the traveling wave ranging is and the following must be satisfied: ： ； The weight formula is obtained by the above and The final fault distance is the weighted sum of the two positioning results: ； wherein is the fault distance for anti-phase contrast calculation, is the fault distance for traveling wave distance calculation.

5. The transformer neutral live fault point judgment detector according to claim 1, characterized in that: The interaction layer realizes human-computer interaction design, the AR real scene navigation module automatically scans when walking along the line after self-checking, the display module supports visible brightness adjustment under sunlight, and the display module displays the fault distance in real time with an accuracy of 0.1 meters, and the screen response time is less than 100ms.

6. The transformer neutral live fault point judgment detector according to claim 1, characterized in that: The audible and visual alarm system of the interaction layer, the limited range of the pre-warning level is greater than 15V, the warning performance of the pre-warning level is yellow light constant on to prompt approaching the fault area, the limited range of the fault level is greater than 36V, the warning performance of the fault level is red light flashing and buzzer ringing to prompt reaching the vicinity of the fault point, and the limited range of the emergency level is greater than 50V, the warning performance of the emergency level is red light constant on, buzzer continuous ringing, and alarm information is sent to the background at the same time.

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