Construction site concealed power cable fault point rapid detection device

Abstract

The utility model relates to the technical field of cable faults, and discloses a construction site concealed power cable fault point rapid detection device which comprises a signal transmitting device and a signal receiving device, the signal receiving device comprises a signal probe and a signal output processing circuit connected to the output end of the signal probe, and the signal probe comprises a shell. Universal wheels are installed outside the head of the shell, a magnetic field sensing module is installed in the head of the shell, the magnetic field sensing module comprises a plurality of groups of orthogonally-arranged magnetic induction coils, the output ends of the magnetic induction coils are connected to the input end of a preamplifier of a signal processing module through shielded twisted pairs, and the output end of the preamplifier is connected with a detector. The detector is connected with the filter, the output end of the filter is connected with the signal processing module through a digital bus, and the signal processing module comprises an inclination angle sensing module and a burial depth calculation module and drives the man-machine interaction module connected to the signal processing module.

Description

TECHNICAL FIELD

[0001] The utility model relates to cable fault technical field, concretely is a construction site dark covering power cable fault point quick detection device. BACKGROUND

[0002] As an important carrier of power transmission and signal transmission, cables play a vital role in various fields of modern society. In order to ensure the safety of the line, the cable laying generally adopts the form of dark covering in the construction site. During use, some uncertain factors in the construction site may cause some short circuit, open circuit, grounding and other faults, such as poor ground drainage leading to damp insulation of dark covering cable, earth subsidence leading to damage of dark covering cable, and insulation aging caused by multiple turnover use of cable line.

[0003] However, when the cable fails, it is often a very challenging task to find the fault location, especially when the faulty cable adopts the form of buried dark covering, the difficulty is greatly increased.

[0004] The buried dark covering cable is usually buried in the ground at a certain depth, which may be under the road, building or green belt area, and the cable cannot be directly observed on the surface.

[0005] After the cable fails, the fault location of the cable cannot be quickly found because the faulty cable is in the form of buried dark covering, which causes long maintenance outage time, causes workers to stay on the site and machinery to be idle, seriously affects the normal construction on site, and needs to study a construction site dark covering power cable fault point quick detection device. SUMMARY

[0006] The utility model discloses in order to solve the current buried dark covering cable fails, the fault position cannot be accurately detected, needs long time maintenance and overhauls, causes workers to stay on the site and machinery to be idle, seriously affects the normal construction on site and a series of problems, provides a construction site dark covering power cable fault point quick detection device.

[0007] The utility model discloses the following technical scheme is adopted to realize:

[0008] The utility model provides a construction site dark covering power cable fault point quick detection device, including signal transmitting device and signal receiving device, signal receiving device includes signal probe, signal output processing circuit is connected to signal probe output, signal probe includes the casing, the head of casing is installed with universal wheel outside, the head of casing is installed with magnetic field sensor module inside, magnetic field sensor module includes a plurality of groups of orthogonal arrangement's magnetic induction coil, the output of magnetic induction coil is connected to the input of preamplifier of signal processing module through shielded twisted pair, the output of preamplifier is connected with detector, detector is connected with filter, the output of filter is connected signal processing module through digital bus, signal processing module includes inclination sensor module and buried depth calculation module, and human-computer interaction module of driving access signal processing module simultaneously.

[0009] When implemented, it includes signal transmitting device and signal receiving device, signal receiving device includes signal probe, signal output processing circuit is connected to signal probe output, signal probe includes the casing, the casing is made of non-conductive diamagnetic material, and an electromagnetic shielding layer is attached to the inner surface thereof, the electromagnetic shielding layer has a multi-layer composite structure, and the electromagnetic shielding layer includes a bonded permalloy layer and a conductive silicone layer to avoid signal interference in the field.

[0010] The casing includes a head and a handheld main body portion, a universal wheel is installed on the head of the casing, the handheld main body portion of the casing is a handheld portion for smoothly moving the signal probe, a magnetic field sensor module is installed in the head of the casing, the magnetic field sensor module includes a plurality of groups of orthogonally arranged magnetic induction coils, the direction resolution is improved through gradient magnetic field detection, and the electromagnetic field vector characteristics are met, specifically, the magnetic induction coils have a gradient differential structure, each group of magnetic induction coils includes two high-permeability magnetic rods symmetrically distributed along the axis of the head of the casing, each high-permeability magnetic rod has a respective detection coil wound thereon, the two detection coils of the same group have opposite winding directions to form a differential signal to eliminate common-mode interference; the axes of the high-permeability magnetic rods are orthogonally distributed in space, the spacing between the detection coils of the same group is 0.8 times the pre-buried depth of the cable to be detected, the magnetic induction coils are installed in the head of the casing through a movable insulating support, the spacing between the magnetic induction coils can be adjusted to adapt to different buried depth scenarios and meet the electromagnetic field attenuation law, preferably, the movable insulating support includes a fixed frame installed on the inner surface of the casing and a movable frame slidingly connected to the fixed frame, the magnetic induction coils are installed on the surface of the movable frame, the fixed frame and the movable frame can be connected in a manner such as a sliding rail and a sliding block, or a sliding groove and a clamping block, which can be realized using existing technologies and will not be described here.

[0011] The output end of the magnetic induction coil is connected to the input end of a preamplifier of the signal processing module through a shielded twisted pair, the preamplifier is installed on the handheld main body part of the shell, the output end of the preamplifier is connected with a detector, the detector is connected with a filter, the filter center frequency is synchronously adjustable with the audio current frequency injected by the cable, and the output end of the filter is connected with the signal processing module through a digital bus.

[0012] The signal processing module comprises an inclination sensing module and a buried depth calculation module, the inclination sensing module comprises a three-axis MEMS accelerometer installed at the center of the head part of the shell, the three-axis MEMS accelerometer monitors the space posture of the signal probe in real time, communicates with the main control unit of the signal processing module through an I2C interface, and outputs three-axis acceleration data in real time to calculate the space posture of the probe and correct the inclination error in the buried depth measurement, and the signal processing module simultaneously drives a human-computer interaction module connected with the signal processing module,

[0013] The human-computer interaction module integrates an acousto-optic dual-mode feedback system, comprises an LED array and a buzzer, the LED array comprises a plurality of RGB LEDs installed on the shell, each LED is connected in series through a driving chip and is connected with the signal processing module, and the color gradient of the LED array indicates the signal strength; the buzzer is connected with the signal processing module through a transistor switching circuit, and the buzzer emits audio alarms of different frequencies according to the trigger instructions.

[0014] Compared with the prior art, the application has the following beneficial effects:

[0015] The construction site underground power cable fault point rapid detection device can accurately locate the fault point position of the underground cable line at the construction site, adopts an advanced detection principle, rapidly scans the cable line through specific signal emission and receiving devices, and accurately determines the specific position of the fault point by using data analysis technology. The device has high detection efficiency, can complete large-area detection work in a short time, has simple process, and does not need complex operation process and a large number of professional equipment. After the cable line at the construction site fails, the device is used, the staff can quickly determine the fault point, timely repair, thereby quickly restoring power supply, effectively avoiding long-time power failure caused by cable failure, further avoiding great influence on construction production, and providing powerful guarantee for efficient operation of the construction site. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The figure shows the structural schematic diagram of the device.

[0017] In the figure, 1 is a universal wheel, 2 is a shell, 3 is an electromagnetic shielding layer, 4 is a high-permeability magnetic rod, 5 is a detection coil, 6 is a preamplifier, 7 is a detector, 8 is a filter, 9 is an LED array, 10 is a buzzer, 11 is a voltage stabilizer, and 12 is an oscillator. Detailed Implementation

[0018] The present invention will now be described in conjunction with specific embodiments.

[0019] A rapid detection device for fault points in concealed power cables at construction sites, such as Figure 1 As shown: It includes a signal transmitting device and a signal receiving device. The signal receiving device includes a signal probe and a signal output processing circuit connected to the output end of the signal probe. The signal probe includes a housing 2, which is made of non-conductive antimagnetic material. An electromagnetic shielding layer 3 is attached to its inner surface. The electromagnetic shielding layer 3 is a multi-layer composite structure, which includes an adhesive permalloy layer and a conductive silicone layer to avoid signal interference on site. The shielding effectiveness of the electromagnetic shielding layer 3 is ≥60dB@1kHz-100kHz.

[0020] The housing 2 includes a head and a handheld main body. A caster wheel 1 is mounted on the outside of the head for movement on the ground. The handheld main body of the housing 2 serves as the handheld and display unit, used to smoothly move the signal probe. A magnetic field sensing module is installed inside the head of the housing 2. This module includes multiple sets of orthogonally arranged magnetic induction coils. Gradient magnetic field detection improves directional resolution and conforms to electromagnetic field vector characteristics. Specifically, the magnetic induction coils adopt a gradient differential structure. Each set of magnetic induction coils includes two high-permeability magnetic rods 4 symmetrically distributed along the axis of the housing head. Each high-permeability magnetic rod 4 has its own detection coil 5 wound on it. The two detection coils 5 in the same set are wound in opposite directions, forming a differential signal to eliminate common-mode interference. The axes of the high-permeability magnetic rods 4 are orthogonally spatially distributed. The spacing between the detection coils 5 in the same set is 0.8 times the pre-buried depth of the cable under test. The magnetic induction coils are installed inside the head of the housing 2 via a movable insulating bracket. The adjustable range of the movable insulating bracket is 20-150mm. To adapt to different burial depth scenarios, the spacing between the magnetic induction coils can be adjusted, conforming to the electromagnetic field attenuation law.

[0021] The output of the magnetic induction coil is connected to the input of the preamplifier 6 of the signal processing module via a shielded twisted pair cable. The preamplifier 6 is mounted on the handheld main body of the housing 2. The output of the preamplifier 6 is connected to the detector 7. The detector 7 is connected to the filter 8. The filtering center frequency of the filter 8 is synchronously adjustable with the frequency of the audio current injected by the cable. The output of the filter 8 is connected to the signal processing module via a digital bus.

[0022] The signal processing module comprises an adaptive noise cancellation unit, adopts an LMS algorithm to dynamically eliminate power frequency interference, and the signal-to-noise ratio is improved by greater than or equal to 40 dB. The signal processing module comprises an inclination sensing module and a buried depth calculation module. The inclination sensing module comprises a three-axis MEMS accelerometer installed at the center of the head of the shell 2, which monitors the spatial posture of the signal probe in real time. The three-axis MEMS accelerometer communicates with the main control unit of the signal processing module through an I2C interface, and outputs three-axis acceleration data in real time to calculate the spatial posture of the probe, which is used to correct the inclination error in the buried depth measurement. The signal processing module simultaneously drives a human-computer interaction module connected to the signal processing module.

[0023] The human-computer interaction module integrates an acousto-optic dual-mode feedback system, comprising an LED array 9 and a buzzer 10. The LED array 9 comprises a plurality of RGB LEDs installed on the shell 2, each LED being connected in series through a driving chip and connected to the signal processing module. The color gradient of the LED array 9 indicates the signal strength. The buzzer 10 is connected to the signal processing module through a transistor switching circuit. The buzzer 10 emits audio alarms of different frequencies according to the triggering instructions. Specifically, the driving chip adopts WS2812B. When the probe is located directly above the cable, the LED displays green and the buzzer is silent. When the probe deviates, the LED gradually changes to red, and the frequency of the buzzer increases with the degree of deviation. The buzzer 10 is a piezoelectric buzzer connected to the main control GPIO pin.

[0024] An oscillator 12 and a voltage stabilizer 11 are connected to the preamplifier, which is used to generate a stable high-frequency sine wave with stable voltage amplitude and reduced distortion. The voltage stabilizer ensures that the amplifier and oscillator are supplied with stable voltage.

[0025] Taking the construction project of the Qiyuan Central Coal Preparation Plant as an example, eight cables are arranged on the construction site, with buried depths of 400 mm, 500 mm, 600 mm, 700 mm, 800 mm, 900 mm, 1100 mm and 1500 mm, respectively.

[0026] 1# ZR-YJV-1KV-3x120 170 meters 2# ZR-YJV-1KV-3x120 156 meters 3# ZR-YJV-1KV-3x120 156 meters 4# ZC-YJV-8.7 / 15KV-3x185 151 meters 5# ZC-YJV-8.7 / 15KV-3x185 226 meters 6# ZC-YJV-8.7 / 15KV-3x185 226 meters 7# ZC-YJV-8.7 / 15KV-3x185 215 meters 8# ZC-YJV-8.7 / 15KV-3x185 226 meters

[0027] 1# cable fault point 50 meters from the beginning is a grounding fault with a buried depth of 400 mm; 2# cable fault point 80 meters from the beginning is a broken line fault with a buried depth of 500 mm; 3# cable fault point 120 meters from the beginning is a phase-to-phase short circuit fault with a buried depth of 600 mm; 4# cable fault point 150 meters from the beginning is a phase-to-phase broken line and grounding fault with a buried depth of 700 mm; 5# cable fault point 200 meters from the beginning is a phase-to-ground fault with a buried depth of 800 mm; 6# cable fault point 210 meters from the beginning is a phase-to-phase broken line fault with a buried depth of 900 mm; 7# cable fault point 215 meters from the beginning is a phase-to-phase short circuit fault with a buried depth of 1100 mm; and 8# cable fault point 220 meters from the beginning is a phase-to-phase broken line and grounding fault with a buried depth of 1500 mm.

[0028] 8 cables are provided with 2 short-circuit fault points, 2 grounding fault points, 2 broken wire fault points and 2 broken wire grounding fault points, and the error of testing the position of the fault point of the buried cable by the isosceles triangle induction method and the acoustic method by using the device is:

[0029] By using the prior art:

[0030] When the buried depth is less than or equal to 500 mm, the detection length is 100 meters, the detection time is 5 minutes, and the accuracy of determining the position of the fault point is 25 mm;

[0031] When the buried depth is greater than 500 mm and less than or equal to 700 mm, the detection length is 200 meters, the detection time is 10 minutes, and the accuracy of determining the position of the fault point is 25-35 mm;

[0032] When the buried depth is greater than 700 mm and less than or equal to 1000 mm, the detection length is 300 meters, the detection time is 15 minutes, and the accuracy of determining the position of the fault point is 35-50 mm;

[0033] When the buried depth is greater than 1000 mm, the detection length is 500 meters, the detection time is 25 minutes, and the accuracy of determining the position of the fault point is 50 mm < accuracy < 5% of the buried depth.

[0034] By using the device:

[0035] When the buried depth is less than or equal to 500 mm, the detection length is 50 meters and 80 meters, the detection time is 2.5 minutes and 4 minutes respectively, and the accuracy of determining the position of the fault point is 25 mm;

[0036] When the buried depth is greater than 500 mm and less than or equal to 700 mm, the detection length is 120 meters and 150 meters, the detection time is 6 minutes and 7.5 minutes respectively, and the accuracy of determining the position of the fault point is 25-35 mm;

[0037] When the buried depth is greater than 700 mm and less than or equal to 1000 mm, the detection length is 200 meters and 210 meters, the detection time is 10 minutes and 10.5 minutes respectively, and the accuracy of determining the position of the fault point is 35-50 mm;

[0038] When the buried depth is greater than 1000 mm, the detection length is 215 meters and 220 meters, the detection time is 10.8 minutes and 11 minutes respectively, and the accuracy of determining the position of the fault point is 50 mm < accuracy < 5% of the buried depth.

[0039] In summary, the detection accuracy of the device can fully meet the requirements of the prior art, and the detection time is significantly shortened. After the operator is further familiar with the device, the detection time can be further shortened. Therefore, the device is beneficial to quickly determining the fault point by the operator, timely repairing, quickly restoring power supply, and effectively avoiding long-time power outage caused by cable failure.

[0040] The utility model requires the scope of protection not to be limited to above specific embodiment, and for the person skilled in the art, the utility model can have multiple deformation and change, any modification, improvement and equivalent replacement in the concept and principle of the utility model should be contained in the protection scope of the utility model.

Claims

1. A construction site dark power cable fault point rapid detection device, comprising a signal emitting device and a signal receiving device, the signal receiving device comprising a signal probe, a signal output processing circuit connected to the output end of the signal probe, characterized in that, the signal probe comprises a shell (2), a universal wheel (1) is mounted on the head of the shell (2), a magnetic field sensing module is mounted in the head of the shell (2), the magnetic field sensing module comprises a plurality of groups of orthogonally arranged magnetic induction coils, the output ends of the magnetic induction coils are connected to the input end of a preamplifier (6) of a signal processing module through shielded twisted pair lines, the output end of the preamplifier (6) is connected with a detector (7), the detector (7) is connected with a filter (8), the output end of the filter (8) is connected with a signal processing module through a digital bus, the signal processing module comprises an inclination sensing module and a buried depth calculation module, and a man-machine interaction module is simultaneously driven to access the signal processing module.

2. The construction site directly laid power cable fault point rapid detection device according to claim 1, characterized in that: Each group of magnetic induction coils comprises two high-permeability magnetic rods (4) symmetrically distributed along the axis of the head of the shell, each high-permeability magnetic rod (4) has a respective detection coil (5) wound thereon, the two detection coils (5) of the same group are wound in opposite directions, and the axes of the high-permeability magnetic rods (4) are orthogonally distributed in space.

3. The construction site directly laid power cable fault point rapid detection device according to claim 2, characterized in that: The spacing between the detection coils (5) of the same group is 0.8 times the pre-buried depth of the cable to be measured.

4. The construction site directly laid power cable fault point rapid detection device according to claim 2, characterized in that: The magnetic induction coils are mounted on the head of the shell (2) through a movable insulating support, and the adjustment range of the movable insulating support is 20-150 mm.

5. The construction site directly laid power cable fault point rapid detection device according to claim 1, characterized in that: An electromagnetic shielding layer (3) is attached to the inner surface of the shell (2), and the electromagnetic shielding layer (3) comprises a bonded permalloy layer and a conductive silicone layer.

6. The construction site directly laid power cable fault point rapid detection device according to claim 5, characterized in that: The shielding effectiveness of the electromagnetic shielding layer (3) is ≥60 dB @ 1 kHz-100 kHz.

7. The construction site directly laid power cable fault point rapid detection device according to claim 1, characterized in that: The man-machine interaction module integrates an acousto-optic dual-mode feedback system, which contains an LED array (9) and a buzzer (10).

8. The construction site directly laid power cable fault point rapid detection device according to claim 7, characterized in that: The LED array (9) comprises a plurality of RGB LEDs mounted on the shell (2), each LED is connected in series through a driving chip, and is connected with the signal processing module.

9. The construction site directly laid power cable fault point rapid detection device according to claim 7, characterized in that: The buzzer (10) is connected with the signal processing module through a transistor switching circuit, and emits audio alarms of different frequencies according to the triggering instructions.

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