Cable on-line monitoring and fault early warning and positioning system

Abstract

The utility model relates to the technical field of cable monitoring, and discloses a cable on-line monitoring and fault early warning and positioning system, which comprises a high-frequency sensor group arranged on a cable shielding layer grounding wire; the current traveling wave acquisition unit comprises a signal conditioning circuit, a high-speed analog-to-digital conversion trigger assembly, a field programmable logic gate array, a central processing unit and a communication module which are electrically connected in sequence; wherein the field programmable logic gate array is electrically connected with a static random access memory. Based on the combined design of the high-frequency sensor group and the field programmable logic gate array, the high-frequency sensor group can capture transient traveling wave signals of the cable shielding layer grounding wire in real time, and high-frequency fault characteristics which cannot be detected by a traditional sensor are covered.

Description

TECHNICAL FIELD

[0001] The utility model relates to cable monitoring technical field especially relates to a cable on -line monitoring and fault early warning and positioning system. BACKGROUND

[0002] With the progress of society and the rapid development of national economy, as the core energy of modern society operation, the demand of power of all walks of life shows the tendency of year-on-year increase.Power cable as the key carrier of power transmission, plays a vital role in the power system, and its use is increasing year by year.However, the cable operation environment is complex and changeable, and the operation mode is unique, which causes the difficulty of finding fault point, longer detection and repair time and other problems, which brings great challenge to the stable operation of power system.Power department urgently needs to give effective early warning before cable fault occurs, and take measures to eliminate hidden troubles in advance to avoid sudden power failure and fire accidents caused by cable short circuit when permanent fault occurs.

[0003] The traditional cable fault detection method has at least the following defects when coping with the demand of modern power cable operation monitoring:

[0004] Passive maintenance: relying on periodic power-off test or manual troubleshooting after fault, unable to monitor the cable operation state in real time, difficult to capture transient insulation deterioration (such as "recoverable fault"), leading to accumulation of hidden troubles;

[0005] Low positioning accuracy: the traditional impedance method has large error (usually hundreds of meters) in distance measurement, and the fault repair takes a long time, affecting the power supply recovery efficiency.

[0006] In the prior art, although some cable monitoring schemes try to improve the traditional method, but its real-time capture ability of transient traveling wave signal of cable shielding layer grounding wire is insufficient, especially difficult to cover high-frequency fault characteristics, while the transient traveling wave signal generated by cable fault contains rich fault information, which makes the existing scheme have great limitations in fault warning and diagnosis, and it is difficult to accurately judge the insulation state of cable.

[0007] Based on this, the present application is proposed. UTILITY MODEL CONTENT

[0008] The utility model aims at solving the problems in the prior art and proposes a cable on-line monitoring and fault early warning and positioning system.

[0009] In order to realize the above-mentioned purpose, the utility model adopts the following technical scheme:

[0010] A cable on-line monitoring and fault early warning and positioning system, comprising:

[0011] A high-frequency sensor group is installed on the cable shielding layer grounding wire.

[0012] The current row wave acquisition unit comprises, in sequence, a signal conditioning circuit, a high-speed analog-digital conversion trigger component, a field programmable logic gate array, a central processing unit and a communication module;

[0013] The field programmable logic gate array is electrically connected with a static random access memory.

[0014] The signal output end of the high-frequency sensor group is connected with the signal input end of the current row wave acquisition unit, and the current row wave acquisition unit sends the collected data to the upper computer through the communication module.

[0015] Preferably, the upper computer comprises an intelligent comprehensive management unit, and the intelligent comprehensive management unit comprises:

[0016] The communication module provides a multi-channel data exchange interface, is connected with the signal output end of the current row wave acquisition unit, and uploads the integrated data to a cloud server.

[0017] The clock synchronization module provides clock synchronization for the field programmable logic gate array.

[0018] The power module provides power supply for the current row wave acquisition unit.

[0019] Preferably, the high-frequency sensor group is electrically connected with the signal conditioning circuit through a current-limiting and voltage-limiting protection circuit.

[0020] Preferably, the high-speed analog-digital conversion trigger component comprises a high-speed analog-digital converter and a high-speed comparator, one-way signals output by the signal conditioning circuit are sent to the high-speed comparator, and the other-way signals are sent to the high-speed analog-digital converter; the high-speed comparator can send a trigger signal to the field programmable logic gate array when detecting that the signals exceed a preset threshold value; and the field programmable logic gate array starts the high-speed analog-digital converter to convert analog signals into digital signals.

[0021] Preferably, the communication module and the communication module are connected in the form of an Ethernet, an SPI interface or light.

[0022] Preferably, the high-frequency sensor group adopts a current row wave high-frequency sensor, and is connected with the current row wave acquisition unit through a multi-core shielding line.

[0023] Compared with the prior art, the current application has the following beneficial effects:

[0024] The utility model discloses a high frequency sensor group and the combination design of field programmable logic gate array, and high frequency sensor group can capture transient traveling wave signal (such as " recoverable fault " produced microsecond electromagnetic pulse) of cable shield layer ground wire in real time, cover the high frequency fault characteristic that traditional sensor cannot detect, cooperate field programmable logic gate array and high speed comparator, only start high speed analog -to -digital conversion when signal amplitude exceeds threshold value, avoid invalid data storage, and high speed analog -to -digital converter complete record traveling wave waveform's steep front, reduce the waveform distortion, and field programmable logic gate array can calculate the time difference of traveling wave arrival in real time, effectively reduce the error, and do not change cable line operation mode and structure, install high frequency current sensor on cable ground conductor, safe and reliable. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 The utility model discloses a kind of cable on-line monitoring and fault early warning and positioning system overall schematic diagram is proposed;

[0026] Figure 2 A kind of cable on-line monitoring and fault early warning and positioning system high frequency sensor group and cable buckle connection structure schematic diagram are proposed in the utility model.

[0027] In the drawing: 1, high frequency sensor group;2, signal conditioning circuit;3, high speed analog-digital conversion trigger component;4, field programmable logic gate array;5, high speed analog-digital converter;6, cloud;7, central processing unit;8, communication module;9, communication module;10, power module;11, current-limiting voltage-limiting protection circuit;12, clock synchronization module;13, high speed comparator. DETAILED DESCRIPTION

[0028] The technical scheme in the embodiments of the utility model will be described clearly and completely in conjunction with the drawings of the embodiments of the utility model, and apparently, the described embodiments are only part of the embodiments of the utility model, not all the embodiments.

[0029] Reference Figure 1 A kind of cable on-line monitoring and fault early warning and positioning system, comprising:

[0030] High frequency sensor group 1 is installed in cable shield layer ground wire, for capturing transient traveling wave signal of cable shield layer ground wire in real time;

[0031] Current traveling wave acquisition unit, including signal conditioning circuit 2, high speed analog-digital conversion trigger component 3, field programmable logic gate array 4, central processing unit 7 and communication module 8 that are electrically connected in sequence;

[0032] Among them, field programmable logic gate array 4 is electrically connected with static random access memory;

[0033] The signal output end of the high-frequency sensor group 1 is connected with the signal input end of the current traveling wave acquisition unit, and the current traveling wave acquisition unit sends the collected data to the upper computer through the communication module 8.

[0034] The system can capture the transient traveling wave signal (such as microsecond electromagnetic pulse generated by "recoverable fault") of the cable shielding layer grounding wire in real time by using the high-frequency sensor group 1, and monitor and analyze the insulation state of the cable according to the phenomenon that the insulation state of the cable after transient grounding is closer to permanent fault, so that the system can reliably give an early warning before permanent grounding fault of the cable line occurs, and the high-frequency fault characteristics that cannot be detected by traditional sensors are covered.

[0035] The field programmable logic gate array 4 cooperates with the high-speed comparator 13 to start high-speed analog-to-digital conversion only when the signal amplitude exceeds the threshold value, so as to avoid invalid data storage; the high-speed analog-to-digital converter 5 completely records the steep front edge of the traveling wave waveform, so as to reduce waveform distortion; the field programmable logic gate array 4 can calculate the traveling wave arrival time difference in real time, effectively reduce errors, and realize fault point ranging by using the voltage traveling wave and current traveling wave fault ranging technology, and the fault ranging accuracy can reach 2.125 m.

[0036] In actual use, the system has short response time; when the cable has transient fault and generates traveling wave signal, the high-frequency sensor group 1 can transmit the collected fault signal to the upper computer through network communication within 5 s, and the fault line and fault waveform can be displayed in real time by cooperating with software, so as to facilitate the on-duty personnel to quickly analyze and process.

[0037] Moreover, the system does not need to change the operation mode and structure of the cable line, and can be installed on the cable grounding conductor by using high-frequency current sensors, which is safe and reliable.

[0038] The cable online monitoring and fault early warning and positioning system described in the application, when working, installs the high-frequency sensor group on the cable shielding layer grounding wire, captures the transient traveling wave signal of the cable shielding layer grounding wire in real time, after the signal is preliminarily processed by the signal conditioning circuit, enters the high-speed analog-digital conversion trigger assembly, the field programmable logic gate array cooperates with the high-speed comparator, when the signal amplitude exceeds the set threshold value, starts the high-speed analog-digital conversion, converts the analog signal into a digital signal, the field programmable logic gate array calculates the traveling wave arrival time difference in real time, and determines the fault point position by using the voltage traveling wave and current traveling wave fault distance measurement technology, wherein the voltage traveling wave and current traveling wave fault distance measurement technology is a known prior art, and will not be described in detail here. Compared with the prior art, the system installs one high-frequency sensor on each cable grounding metal shielding layer, covers the high-frequency fault characteristics that cannot be detected by the traditional sensor, can accurately monitor the insulation state of the cable, collects the weak transient current signal of the cable before the fault occurs, and transmits it to the traveling wave current collection unit, after signal processing by the collection unit, converts it into digital information and uploads it to the system host computer, the system software analyzes the cable main insulation condition, grades the cable fault early warning, and selects the fault line. At the same time, the system collects the monitored cable bus PT, collects Ua, Ub, Uc, UL voltage traveling wave signals through the ultra-high frequency voltage signal collection unit, which is used to determine the fault phase and calculate the cable fault distance. The system integrates advanced digital sensor technology, high-speed data acquisition, communication technology, computer technology and cloud computing, without changing the operation mode and structure of the cable line, is safe and reliable, has short response time, high positioning accuracy, can adapt to harsh operating environment, and provides protection for the power cable in operation.

[0039] In the embodiment, the host computer includes an intelligent comprehensive management unit, and the intelligent comprehensive management unit includes:

[0040] The communication module 9 provides a multi-channel data exchange interface, is connected with the signal output end of the current traveling wave collection unit, integrates data and uploads to the cloud 6 server, provides sufficient user space for each user, the user can access the on-site system monitoring situation at any time and place through the browser, and the system historical data is permanently stored, facilitating historical review, determining the cable operation state, realizing real-time early warning, line selection and distance measurement before the fault, and thus realizing the state maintenance of the cable and improving the economic benefit of the enterprise;

[0041] The clock synchronization module 12 provides clock synchronization for the field programmable logic gate array 4;

[0042] The power module 10 provides power supply for the current traveling wave collection unit.

[0043] In the examples of the present application, when the system is working, the current row wave acquisition unit collects the transient row wave signal of the cable, and then transmits the data to the communication module of the intelligent integrated management unit through the signal output end. The communication module uploads the data to the cloud server after integration. Users can access the cloud data through the browser to understand the system monitoring situation. The clock synchronization module provides clock synchronization for the field programmable logic gate array to ensure the accuracy of the processing of the row wave signal. The power module continuously supplies power to the current row wave acquisition unit to ensure uninterrupted acquisition work. The modules work together to realize online monitoring and fault warning of the cable.

[0044] The cable online monitoring and fault warning and positioning system described in the present application realizes real-time warning of cable faults, accurate line selection and distance measurement, state maintenance of the cable, reduction of power outage time and maintenance cost, improvement of enterprise economic benefit, and stable operation of the power system through the synergistic effect of the communication module 9, the clock synchronization module 12, the power module 10, the cloud 6, the field programmable logic gate array 4, the high-speed comparator 13, the central processing unit 7, the signal conditioning circuit 2, and the high-frequency sensor group 1.

[0045] In the present embodiment, the high-frequency sensor group 1 is electrically connected to the signal conditioning circuit 2 through the current and voltage limiting protection circuit 11. This setting enables the transient row wave signal collected by the high-frequency sensor group 1 to be processed by the current and voltage limiting protection circuit 11 before being transmitted to the signal conditioning circuit 2, accurately controls the current and voltage size, ensures that the signal entering the signal conditioning circuit is within a safe and stable range, avoids damage to the signal conditioning circuit caused by excessive current or voltage, and thus guarantees the stable operation of the entire system.

[0046] In the present embodiment, the high-speed analog-to-digital conversion trigger assembly 3 includes a high-speed analog-to-digital converter 5 and a high-speed comparator 13. The signal output by the signal conditioning circuit 2 is sent to the high-speed comparator 13 and the high-speed analog-to-digital converter 5. The high-speed comparator 13 can send a trigger signal to the field programmable logic gate array 4 when the detected signal exceeds the preset threshold. The field programmable logic gate array 4 starts the high-speed analog-to-digital converter 5 to convert the analog signal to a digital signal.

[0047] This setting avoids invalid data storage and saves storage space by starting the high-speed analog-to-digital converter only when the signal detected by the high-speed comparator exceeds the threshold. At the same time, the high-speed analog-to-digital converter starts in time when the signal exceeds the threshold, which can record the steep front of the row wave form completely, reduce waveform distortion, and improve the accuracy of signal conversion. The field programmable logic gate array accurately controls the start of the high-speed analog-to-digital converter according to the trigger signal, making the entire system more efficient and reliable, and enabling more accurate monitoring of the insulation state of the cable to timely discover hidden faults and provide strong protection for the safe operation of the cable.

[0048] In the embodiment, the communication module 8 and the communication module 9 are connected in the form of Ethernet, SPI interface or light.

[0049] In the embodiment, the high-frequency sensor group 1 adopts a current traveling wave high-frequency sensor, and is connected with a current traveling wave acquisition unit through a multi-core shielding wire. In the example of the present application, the high-frequency sensor group 1 can adopt a commercially available open-type current transformer, a Rogowski coil current sensor, etc.

[0050] Embodiment 2

[0051] The difference between the embodiment and the embodiment 1 is that:

[0052] In the embodiment, the high-frequency sensor group 1 adopts a circulating current acquisition sensor, which is arranged in an open core structure and buckled at a cable shielding layer grounding wire (as shown in the figure), can be used for part of single-core cables, so that the system can monitor the insulating condition of the outer sheath of the line in real time, and perform fault alarm for the cable with abnormal outer sheath insulation. Figure 2

[0053] In the embodiment, one side of the circulating current acquisition sensor is provided with a buckle part, and the buckle part includes two clamping blocks slidingly arranged on one side of a circulating current acquisition sensor shell, and a plug head and a plug hole part arranged on the two clamping blocks, respectively.

[0054] The plug head includes two pressable pressing plates arranged on the clamping blocks and a plug block arranged at the bottom end of the mounting plate.

[0055] The plug hole part includes a plug slot arranged on the clamping block and two limiting grooves arranged in the plug slot, the plug slot corresponds to the position of the pressing plate, and the plug block is matched with the limiting groove.

[0056] The materials of the pressing plate and the plug block are both high-elastic plastic (such as TPU (thermoplastic polyurethane), TPE (thermoplastic elastomer), etc.), so that the pressing plate has good elasticity and can reset after being stressed. After pressing the two pressing plates to make them enter the plug slot, the pressing plates are released to reset, and the plug block is inserted into the limiting groove, so that the circulating current acquisition sensor can be conveniently installed on the outer periphery of the cable.

[0057] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any skilled person in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.​

Claims

1. A cable on-line monitoring and fault pre-warning and positioning system, characterized in that: The utility model relates to a high-frequency current traveling wave acquisition system and method, comprising: a high-frequency sensor group installed on a cable shielding layer grounding wire; a current traveling wave acquisition unit comprising a signal conditioning circuit, a high-speed analog-digital conversion trigger component, a field programmable logic gate array, a central processing unit and a communication module connected in sequence; wherein the field programmable logic gate array is electrically connected with a static random access memory; wherein the signal output end of the high-frequency sensor group is connected with the signal input end of the current traveling wave acquisition unit, and the current traveling wave acquisition unit sends the collected data to an upper computer through the communication module.

2. The cable on-line monitoring and fault pre-warning and locating system according to claim 1, characterized in that: The upper computer comprises an intelligent comprehensive management unit, which comprises: a communication module providing a multi-channel data exchange interface, connected with the signal output end of the current traveling wave acquisition unit and uploading the integrated data to a cloud server; a clock synchronization module providing clock synchronization for the field programmable logic gate array; a power module providing power supply for the current traveling wave acquisition unit.

3. The cable on-line monitoring and fault pre-warning and locating system according to claim 1, characterized in that: The high-frequency sensor group is electrically connected with the signal conditioning circuit through a current-limiting and voltage-limiting protection circuit.

4. The cable on-line monitoring and fault pre-warning and locating system according to claim 2, characterized in that: The high-speed analog-digital conversion trigger component comprises a high-speed analog-digital converter and a high-speed comparator, one way of the signal output by the signal conditioning circuit is sent to the high-speed comparator, and the other way is sent to the high-speed analog-digital converter, the high-speed comparator can send a trigger signal to the field programmable logic gate array when detecting that the signal exceeds a preset threshold, and the field programmable logic gate array starts the high-speed analog-digital converter to convert the analog signal into a digital signal.

5. The cable on-line monitoring and fault pre-warning and locating system according to claim 2, characterized in that: The communication module and the communication module are connected in the mode of Ethernet, SPI interface or light.

6. The cable on-line monitoring and fault pre-warning and locating system according to claim 1, characterized in that: The high-frequency sensor group adopts a circulating current acquisition sensor, which is arranged in an open core structure and buckled at the cable shielding layer grounding wire.

7. The cable on-line monitoring and fault pre-warning and locating system according to claim 1, characterized in that: The high-frequency sensor group adopts a current traveling wave high-frequency sensor, which is connected with the current traveling wave acquisition unit through a multi-core shielding wire.

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