Underground cable high-resistance fault positioning system

Abstract

The utility model discloses an underground cable high-resistance fault positioning system, which belongs to an underground cable monitoring device, and comprises a transmitter and a receiver, and more importantly, the system also comprises a high-resistance fault positioning acquisition sensor, the high-resistance fault positioning acquisition sensor is provided with an A end and a B end, the A end and the B end of the high-resistance fault positioning acquisition sensor are connected through a signal line, and the A end of the high-resistance fault positioning acquisition sensor is connected to the receiver; the receiver is used for comparing the first phase signal with the second phase signal, and determining a high-resistance fault point of the underground cable according to the change of the first phase signal and the second phase signal; according to the underground high-resistance cable fault positioning method, the high-resistance fault positioning acquisition sensor is additionally arranged, the phase signal from the transmitter is acquired by a human body, and the fault position of the underground high-resistance cable is positioned by using the phase difference algorithm, so that compared with traditional high-voltage flash, the cable can be prevented from being burnt out, and the fault positioning accuracy is relatively high.

Description

TECHNICAL FIELD

[0001] The utility model relates to an underground cable monitoring device, more specifically, the utility model mainly relates to an underground cable high-resistance fault positioning system. BACKGROUND

[0002] Underground cable laying is gradually applied to various scenes such as cities due to its concealment, but once a fault occurs, it will bring difficulty to maintenance. When positioning the fault, the traditional method generally uses acoustic-magnetic synchronous method (fixed-point instrument) or step voltage method (A support), both of which are different instruments, and engineering personnel need to carry different equipment to find faults according to different faults: high-resistance fault (1000Ω or more) uses acoustic-magnetic synchronous method (fixed-point instrument), the transmitter applies high-voltage flash signal (generally 8KV, 16KV, 32KV) to the fault cable, generates discharge signal at the fault point position, and gradually burns down the high-resistance fault impedance, and the fixed-point instrument receives the discharge signal at the fault point position; low-resistance fault (1000Ω or lower impedance) uses A support step voltage method to locate the fault, the transmitter sends a low-voltage pulse signal, and the receiver connects the A support to determine the fault point by step voltage. In view of the foregoing problems, especially for high-resistance faults, when reaching several kilo-ohms or meg-ohms, for example, 2MΩ grounding fault, communication optical cable, railway control cable, street lamp cable, etc. cannot be positioned by high-voltage flash method, because adding high-voltage flash signal to these low-voltage cables will damage (burn) these cables, or cause communication signal or railway control signal malfunction, therefore, it is necessary to further research and improve the device for detecting and positioning high-resistance faults of underground cables. SUMMARY

[0003] One of the purposes of the utility model is to provide an underground cable high-resistance fault positioning system to solve the technical problems that similar technologies in the prior art cannot position the faults of underground high-resistance cables, and high-voltage flash method is easy to burn cables.

[0004] To solve the above technical problems, the utility model adopts the following technical scheme:

[0005] The utility model provides a kind of underground cable high resistance fault location system, including transmitter and receiver, more important, system further includes high resistance fault location collection sensor, the high resistance fault location collection sensor has A end and B end, the A end and B end of the high resistance fault location collection sensor are connected by signal line, the A end and B end of the high resistance fault location collection sensor are also respectively accessed receiver;Transmitter is used to emit phase signal with direction to underground cable;The A end of high resistance fault location collection sensor is used to collect phase signal from transmitter by human body, and after treating the phase signal, as first phase signal, it is transmitted to the receiver;The B end of high resistance fault location collection sensor is used to collect phase signal from transmitter by human body, and after treating the phase signal, as second phase signal, it is transmitted to the receiver;Receiver is used to compare first phase signal and second phase signal, by the change of the first phase signal and second phase signal, determine underground cable high resistance fault point.

[0006] As preferred, further technical solutions are: the A end of the high resistance fault location collection sensor has first collection coil, the first collection coil is wound on soft magnetic core, the first collection coil is also accessed first PCB board, the first collection coil is used to collect phase signal, and is transmitted to first PCB board, by first PCB board, as first phase signal, it is transmitted to the receiver after amplification and analog-digital conversion.

[0007] Further technical solutions are: the B end of the high resistance fault location collection sensor has second collection coil, the second collection coil is wound on magnetic bar, the second collection coil is also accessed second PCB board, the second collection coil is used to collect phase signal, and is transmitted to second PCB board, by second PCB board, as second phase signal, it is transmitted to the receiver after amplification and analog-digital conversion.

[0008] Further technical solutions are: the second collection coil is connected with the spring in the inner bottom of the shell of the B end of high resistance fault location collection sensor, the shell is cylindrical, and the two ends of the spring are respectively in contact with the second collection coil and the inner bottom of the shell.

[0009] Further technical solutions are: the first collection coil is connected with the spring in the inner bottom of the shell of the A end of high resistance fault location collection sensor, the two ends of the shell have bracelet, the two ends of the spring are respectively in contact with the first collection coil and the inner bottom of the shell, and the first collection coil and soft magnetic core are both placed in the interior of the bracelet.

[0010] Further technical solutions are: the receiver includes a control module, the control module accesses a phase signal interface, the control module is used for accepting the first phase signal and the second phase signal through the phase signal interface;The control module also accesses 3D magnetic rod antenna, geographic positioning module, Bluetooth module, 4G / 5G module and operation module respectively;The 3D magnetic rod antenna is used for multidimensional detection of the position of underground pipeline;The geographic positioning module is used for collecting the position information of the current underground cable high resistance fault point, and transmitting to the cloud server through the 4G / 5G module;The Bluetooth module is used for linkage with other intelligent terminals;The operation module is used for operating the control module to control the running state of the receiver.

[0011] Further technical solutions are: the system further includes a cloud server, the cloud server is used for drawing the electronic map of the underground cable of the position of the current underground cable high resistance fault point according to the position information.

[0012] Compared with the prior art, one of the beneficial effects of the utility model is: by adding high resistance fault positioning acquisition sensor, the phase signal from the transmitter is collected by the human body, and then the fault position of the underground high resistance cable is positioned by using phase difference algorithm, compared with the traditional high pressure flash, the cable can be avoided from being burnt out, and the accuracy of fault positioning is higher, and the underground cable high resistance fault positioning system provided by the utility model has simple structure, can be modified based on the existing transmitter and receiver device, and has wide application range. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 It is the fault positioning principle diagram for explaining one embodiment of the utility model.

[0014] Figure 2 It is the use state diagram for explaining one embodiment of the utility model.

[0015] Figure 3 It is Figure 2 It is the A end structure schematic view of high resistance fault positioning acquisition sensor.

[0016] Figure 4 It is Figure 2 It is the B end structure schematic view of high resistance fault positioning acquisition sensor.

[0017] Figure 5 It is the receiver structure schematic block diagram for explaining one embodiment of the utility model.

[0018] In the figure, 1 is a transmitter, 2 is a receiver, 3 is an A end of a high-resistance fault positioning collection sensor, 31 is a first collection coil, 32 is a soft magnetic core, 33 is a first PCB board, 34 is a watch case, 35 is a wristband, 4 is a B end of the high-resistance fault positioning collection sensor, 41 is a second collection coil, 42 is a magnetic rod, 43 is a second PCB board, and 44 is an outer case. DETAILED DESCRIPTION

[0019] The utility model will be further described below with reference to the drawings.

[0020] Reference Figure 1 As shown in the figure, one embodiment of the utility model is a high-resistance fault positioning system for underground cables, which comprises a transmitter, a receiver and a high-resistance fault positioning collection sensor.

[0021] That is, when the cable path is detected, the cable is identified and the fault is positioned, the transmitter sends multiple frequency signals, and the receiver receives the signals on the ground. That is, the transmitter sends signals of different frequencies on the cable, and a signal loop is formed between the cable core or the armor and the ground, and the receiver receives the current magnetic field signals of the cable core or the metal armor on the ground, so as to calculate the phase value and position the fault point. At the same time, the cable path depth detection, identification and other functions are realized.

[0022] The active detection frequencies of both are: 11 Hz, 16 Hz, 22 Hz, 32 Hz, 33 Hz, 64 Hz, 66 Hz, 98 Hz, 128 Hz, 196 Hz, 256 Hz, 273 Hz, 320 Hz, 480 Hz, 491 Hz, 512 Hz, 526 Hz, 577 Hz, 640 Hz, 960 Hz, 982 Hz, 1024 Hz, 1052 Hz, 1154 Hz, 1280 Hz, 2.56 kHz, 3.20 kHz, 4.09 kHz, 5.12 kHz, 6.4 kHz, 8.192 kHz, 8440 Hz, 8928 Hz, 9820 Hz, 10 kHz, 33 kHz, 66 kHz, 82 kHz, 83.1 kHz, 131 kHz, 133 kHz, 201 kHz (of which 11 Hz, 16 Hz, 22 Hz, 32 Hz, 33 Hz, 64 Hz, 66 Hz, 98 Hz, 128 Hz, 196 Hz, 256 Hz, 273 Hz, 320 Hz, 480 Hz, 491 Hz, 512 Hz, 526 Hz, 577 Hz, 640 Hz, 960 Hz, 982 Hz, 1024 Hz, 1052 Hz, 1154 Hz, 1280 Hz, 2.56 kHz, 3.20 kHz, 4.09 kHz, 5.12 kHz, 6.4 kHz, these frequency signals have directivity, and the receiver can identify the signal direction, and when fault positioning, the receiver on the ground can search the phase signal of the transmitted signal in cable transmission); and the power frequency passive detection frequency is: 50 Hz, 60 Hz.

[0023] The transmitter is designed to transmit signals at high, medium and low power, with low power being 15W, medium power being 200W, and high power being 2000W. Low-power transmission is used for fault positioning of communication cables below 1000V, railway control cables, and street lamp cables. Medium-power transmission is used for fault positioning of 10KV and 35KV power cables, and high-power transmission is used for fault positioning of 110KV and above high-voltage cables. At the same time, the transmitter integrates the DTR traveling wave fault ranging function, which can pre-position the fault distance position of low-resistance fault cables. The transmitter transmitted signals include direct connection method loading signals, which are used for cables disconnected during power failure, and signals are added from the core wire; they can also be used for live cables, through the armor signal. Coupling method loading signal, that is, for live cable or power-off cable, the cable has armor ground at both ends to form a loop. Induction method loading signal, that is, directly sensing signal from the ground to the cable, the cable has armor ground at both ends to form a signal transmission loop, which is suitable for live and power-off cables.

[0024] The receiver receives the transmitting signal of the transmitter transmitted through the metal layer of the cable on the ground, so as to test the path of the cable in the ground, the burying depth and the fault positioning.

[0025] The high-resistance fault positioning collection sensor adopts a phase difference measurement method, can quickly position the high-resistance fault below 3MΩ, and the traditional TDR range finder can only pre-position the fault below 1000Ω.

[0026] In the embodiment, the high-resistance fault positioning collection sensor has an A end and a B end, and the A end and the B end of the high-resistance fault positioning collection sensor are connected through a signal line, and the A end and the B end of the high-resistance fault positioning collection sensor are also respectively connected to the receiver 2.

[0027] The transmitter 1 is used for transmitting a phase signal with a direction to the underground cable.

[0028] The A end of the high-resistance fault positioning collection sensor is used for collecting the phase signal from the transmitter 1 through the human body, processing the phase signal, and transmitting the phase signal as a first phase signal to the receiver 2. Similarly, the B end of the high-resistance fault positioning collection sensor is used for collecting the phase signal from the transmitter 1 through the human body, processing the phase signal, and then transmitting the phase signal as a second phase signal to the receiver 2.

[0029] The receiver 2 is used for comparing the first phase signal and the second phase signal, and determining the high-resistance fault point of the underground cable through the change of the first phase signal and the second phase signal.

[0030] Specifically, in combination with Figure 3 As shown in the figure, the A end of the high-resistance fault positioning collection sensor has a first collection coil 31, the first collection coil 31 is wound on a soft magnetic core 32, and the first collection coil 31 is also connected to a first PCB board 33. The first collection coil 31 is used for collecting the phase signal and transmitting the phase signal to the first PCB board 33. The first PCB board 33 has a signal amplifier and an analog-to-digital converter, and then the first PCB board 33 can amplify and perform analog-to-digital conversion, and transmit the phase signal as a first phase signal to the receiver 2.

[0031] Further, in order to facilitate wearing and using, the A end of the high-resistance fault positioning and collecting sensor can be designed in the form of a wristband, so that the operator can wear the A end of the high-resistance fault positioning and collecting sensor with one hand and hold the receiver 2 with the other hand. That is, the first collecting coil 31 is connected with the spring at the inner bottom of the shell 34 of the A end of the high-resistance fault positioning and collecting sensor, both ends of the shell 34 have wristband bands 35, and both ends of the spring are in contact with the first collecting coil 31 and the inner bottom of the shell 34 respectively. The first collecting coil 31 and the soft magnetic core 32 are both arranged inside the wristband bands 35.

[0032] Similarly, as shown in Figure 4 The B end of the high-resistance fault positioning and collecting sensor has a second collecting coil 41, the second collecting coil 41 is wound around a magnetic rod 42, and the second collecting coil 41 is connected to a second PCB 43. The second collecting coil 41 is used to collect a phase signal and transmit it to the second PCB 43. The second PCB 43 also has a corresponding signal amplifier and an analog-to-digital converter. After amplification and analog-to-digital conversion by the second PCB 43, the second phase signal is transmitted to the receiver 2.

[0033] Further, the B end of the high-resistance fault positioning and collecting sensor can be designed as a cylindrical shape for easy holding. Then, the outer shell 11 can be designed as a cylinder, and the second collecting coil 41 inside the outer shell 11 is connected with the spring at the inner bottom of the outer shell 44 of the B end of the high-resistance fault positioning and collecting sensor, and both ends of the spring are in contact with the second collecting coil 41 and the inner bottom of the outer shell 44 respectively.

[0034] The high-resistance fault positioning principle is that there is a large distributed capacitance between the cable core wires and between the core wires and the armored metal layer of the ground. The original fault detection method is affected by the distributed capacitance. This method takes advantage of the existence of the distributed capacitance, that is, even if there is a high-resistance fault, the signal phase before and after the fault point will change greatly. By measuring the phase difference of the signals before and after the fault point, the high-resistance grounding fault of the cable can be positioned.

[0035] Specifically, as Figure 6As shown, the signal transmitter injects a low-frequency sinusoidal voltage signal between the fault core and the ground, and due to the existence of the grounding fault resistance Rx and the distributed capacitance C to the ground, a closed loop is formed between the cable core and the ground, under the action of the alternating voltage signal, the loop generates an alternating current I. The current in the fault line core is always decreasing from point P to point D; since the distributed capacitance of the line core to the ground is uniformly distributed before the grounding fault point X, the current amplitude from point P to point A is uniformly reduced, and after passing through the fault point X, in addition to the leakage current caused by the distributed capacitance, the leakage current caused by the grounding resistance is also reduced, so the current amplitude is suddenly reduced after passing through the fault point. Current relationship: IP > IA > IB > ID. Before the fault point X: the current phase of each measurement point P-A-B leads the voltage phase of the grounding fault point X, and the current phase leads the voltage phase gradually decreases: φP> φA> φB; After passing through the grounding fault point X, it suddenly becomes 90°, φD= 90°. Therefore, the positioning of the high-resistance grounding fault can be realized by testing the phases before and after the fault point.

[0036] As mentioned above, as Figure 1 With Figure 2 As shown above, the phase difference measurement algorithm requires two people to operate the high-resistance fault positioning sensor, one holding the receiver and wearing a bracelet-type (similar to a watch shape) phase collection sensor A, and the other holding the phase collection sensor B, with a distance of 4-5 meters between AB. The receiver collects the directional phase signal sent by the transmitter through the human body and the collectors at both ends of AB.

[0037] The A end of the high-resistance fault positioning collection sensor is designed as a bracelet-type collector, because the A end engineer needs to hold a pipeline path instrument (to detect the path depth and positioning information of the underground cable), and it is more convenient for the A end engineer to wear a watch-type sensor, so a bracelet and watch structure is designed.

[0038] During the fault positioning process, the A end engineer of the high-resistance fault positioning collection sensor collects the phase signal from the transmitter through the human body, and transmits it to the stainless steel lower shell 5 of the bracelet through the arm, and the coil lead-in interface 6 is installed at the position of the stainless steel lower shell. The collected phase signal is connected to the A end phase signal processing PCB through the coil 2, and after the phase signal is processed by the A end PCB circuit and chip, it is transmitted to the receiver through the phase signal output line 10, and then compared with the phase signal of the B end.

[0039] Similarly: the B end of the high resistance fault positioning collection sensor The phase signal of the transmitter is collected by the human body to the ground, and the B end phase collection sensor is held in the hand. The B end phase collection sensor shell is made of stainless steel material. The phase signal collected by the human body is transmitted to the stainless steel shell through the hand holding method. The bottom of the stainless steel shell is connected with the internal spring. The spring is connected with the coil. The coil is wound around the magnetic rod and connected to the B end phase processing PCB board. After the phase signal is processed by the B end PCB circuit and chip, it is transmitted to the receiver through the phase signal output line 12, and then compared with the phase signal of the A end.

[0040] Due to the distributed capacitance and fault grounding resistance of the cable, the phases before and after the fault point are opposite. When the A end collection sensor gradually approaches the fault point, the positive phase gradually increases. When the A end collection sensor passes through the fault point, the phase immediately reverses and a negative phase value appears. When the fault point is in the center position of the AB two sensors, the phase is 0°. Therefore, through the sensor, high resistance faults can be quickly located, including low resistance faults, and the operation is simpler and faster, saving a lot of time and manpower.

[0041] The phase signals collected by the AB ends of the high resistance fault positioning collection sensor are transmitted to the receiver through the respective PCB circuit and processing chip. The collected signals are first amplified, detected, filtered, and then amplified again to convert them into digital phase signals, which are transmitted to the receiver. The receiver compares and analyzes the two signals and gives the final phase difference value to locate the fault point.

[0042] Reference Figure 5 As shown in the above receiver (2), the control module is connected to the phase signal interface. The control module is used to accept the first phase signal and the second phase signal through the phase signal interface. The control module is also connected to the 3D magnetic rod antenna, the geographic positioning module (such as GPS or Beidou satellite module), the Bluetooth module, the 4G / 5G module and the operation module (including physical buttons and touch screen). The 3D magnetic rod antenna is used to detect the position of the underground pipeline in multiple dimensions. The geographic positioning module is used to collect the position information of the current underground cable high resistance fault point and transmit it to the cloud server through the 4G / 5G module. The Bluetooth module is used for linkage with other intelligent terminals. The operation module is used to operate the control module to control the running state of the receiver 2. Further, the system in the above embodiment also includes a cloud server, which is used to draw an electronic map of the underground cable at the position of the current underground cable high resistance fault point according to the position information.

[0043] Further, the APP program running on the intelligent terminal can realize electronic map drawing by relying on GNSS data of the cloud server. The test data is presented on the map completely and accurately, and all cable information can be directly queried on the map. The text description and photo information of all identification points can be directly clicked to view. The map data can be directly imported into CAD, and the full-factor cable path map and fault positioning map can be automatically generated, drawn and output in the CAD software, thereby realizing full-factor, standardized and consistent drawing, storage and digitization.

[0044] In addition to the above, it should also be noted that the "one embodiment", "another embodiment", "embodiment" and the like mentioned in the specification refer to the specific features, structures or characteristics described in conjunction with the embodiment, which are included in at least one embodiment described in the general description of the application. The same expression appears in many places in the specification does not necessarily refer to the same embodiment. Further, when a specific feature, structure or characteristic is described in conjunction with any embodiment, it is claimed that the implementation of such feature, structure or characteristic in conjunction with other embodiments also falls within the scope of the present application.

[0045] Although the present application has been described herein with reference to the various illustrative embodiments, it should be understood that various modifications and implementations can be devised by those skilled in the art, which will fall within the scope and spirit of the present application. More specifically, many variations and modifications of the subject combination layout, its components and / or layout can be made within the scope and spirit of the present application, as disclosed in the specification, drawings and claims. In addition to the variations and modifications of the components and / or layout, other uses will also be apparent to those skilled in the art.

Claims

1. A high impedance fault location system for underground cables comprising a transmitter and a receiver, characterized in that: The high-resistance fault positioning collection sensor has an A end and a B end, the A end and the B end of the high-resistance fault positioning collection sensor are connected through a signal line, and the A end and the B end of the high-resistance fault positioning collection sensor are also respectively connected to the receiver; The transmitter is used for transmitting a phase signal with a direction to the underground cable; The A end of the high-resistance fault positioning collection sensor is used for collecting the phase signal from the transmitter through the human body, processing the phase signal, and transmitting the processed phase signal as a first phase signal to the receiver; The B end of the high-resistance fault positioning collection sensor is used for collecting the phase signal from the transmitter through the human body, processing the phase signal, and transmitting the processed phase signal as a second phase signal to the receiver; The receiver is used for comparing the first phase signal and the second phase signal, and determining the high-resistance fault point of the underground cable through the changes of the first phase signal and the second phase signal.

2. The high impedance fault locating system for underground cables of claim 1, wherein: The A end of the high-resistance fault positioning collection sensor has a first collection coil, the first collection coil is wound on a soft magnetic core, and the first collection coil is also connected to a first PCB board; the first collection coil is used for collecting a phase signal and transmitting the phase signal to the first PCB board; after amplification and analog-to-digital conversion by the first PCB board, the phase signal is transmitted as a first phase signal to the receiver.

3. The high impedance fault locating system for underground cables of claim 1 or 2, characterized in that: The B end of the high-resistance fault positioning collection sensor has a second collection coil, the second collection coil is wound on a magnetic rod, and the second collection coil is also connected to a second PCB board; the second collection coil is used for collecting a phase signal and transmitting the phase signal to the second PCB board; after amplification and analog-to-digital conversion by the second PCB board, the phase signal is transmitted as a second phase signal to the receiver.

4. The high impedance fault locating system for underground cables of claim 3, wherein: The second collection coil is connected to a spring in the inner bottom of the shell of the B end of the high-resistance fault positioning collection sensor, the shell is cylindrical, and the two ends of the spring are respectively in contact with the second collection coil and the inner bottom of the shell.

5. The high impedance fault locating system for underground cables of claim 2, wherein: The first collection coil is connected to a spring in the inner bottom of the shell of the A end of the high-resistance fault positioning collection sensor, the two ends of the spring are respectively in contact with the first collection coil and the inner bottom of the shell, and the first collection coil and the soft magnetic core are both arranged in the inside of the bracelet.

6. The high impedance fault locating system for underground cables of claim 1, wherein: The receiver comprises a control module, the control module is connected to a phase signal interface, and the control module is used for receiving the first phase signal and the second phase signal through the phase signal interface; The control module is also connected to a 3D magnetic rod antenna, a geographic positioning module, a Bluetooth module, a 4G / 5G module, and an operation module; The 3D magnetic rod antenna is used for multi-dimensional detection of the position of the underground pipeline; The geographic positioning module is used for collecting position information of the current high-resistance fault point of the underground cable and transmitting the position information to a cloud server through the 4G / 5G module; The Bluetooth module is used for linkage with a smart terminal; The operation module is used for operating the control module to control the operating state of the receiver.

7. The high impedance fault locating system of claim 6, wherein: The system further comprises a cloud server configured to draw an electronic map of the underground cable at the location of the current high-resistance fault point of the underground cable according to the location information.

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