CN217689246U

CN217689246U - Distributed fault detection device and system for overhead transmission line

Info

Publication number: CN217689246U
Application number: CN202221445538.XU
Authority: CN
Inventors: 刘思; 崔敏
Original assignee: Guangzhou Baichuan Electric Technology Co ltd
Current assignee: Guangzhou Baichuan Electric Technology Co ltd
Priority date: 2022-06-10
Filing date: 2022-06-10
Publication date: 2022-10-28
Anticipated expiration: 2032-06-10

Abstract

The application relates to a distributed fault detection device and system of overhead transmission line. The system induces current signals on a power transmission line in a distributed mode through a detection terminal on the power transmission line, the current signals are converted into voltage signals, the driving capacity is enhanced through operational amplifier, single-end signals are converted into differential signals, the differential signals are converted into digital signals through an ADC (analog to digital converter) chip, the digital signals are transmitted to a single chip microcomputer after being collected at a high speed through an FPGA (field programmable gate array) chip, the FPGA chip also achieves synchronization of time information through second pulse of a GPS (global position system), the single chip microcomputer packs and transmits received humiture information and GPS information around a collection board and signals transmitted by the FPGA together to an upper computer, the upper computer converts the received information, meanwhile, the upper computer compares the received information with a database, diagnoses fault types, and positions faults. This application is transformed into differential signal from single-ended through the signal, and the interference killing feature of reinforcing signal self increases temperature and humidity sensor and will send the early warning if the high temperature or the too high host computer of humidity, and prevention fault detection device is destroyed.

Description

Distributed fault detection device and system for overhead transmission line

Technical Field

The application relates to the technical field of power transmission line monitoring, in particular to a distributed fault detection device and system for an overhead power transmission line.

Background

Electric power is an indispensable part in modern people's life, but when electric power is transported through a power transmission line, events such as lightning stroke (lightning shielding failure, lightning counterattack) or non-lightning stroke (tree barriers, mountain fire, hanging objects, windage yaw and ice coating) often occur on the power transmission line, and these events often cause the power transmission line fault and influence the transportation of the circuit.

In prior art, to the monitoring of power transmission line trouble, can adopt to carry out signal acquisition back and directly transmit for the host computer after simply handling the signal usually, according to the signal of fault point feedback, judge the fault type again, and fault point position, but this kind of mode signal is disturbed easily in transmission process, still has EMI to produce, and the easy distortion of received signal. Also in the prior art there is no protection for the detection means, which would become easily damaged in case of too high temperature or humidity.

SUMMERY OF THE UTILITY MODEL

In order to overcome the problems in the related art, the application provides a distributed fault detection device for a power transmission line, which can convert a voltage signal induced by a sensor from the power transmission line into a differential signal by using an operational amplifier circuit and a single-ended to differential circuit, enhance the anti-interference capability of the signal and inhibit the generation of EMI.

The first aspect of the application provides a distributed fault detection device for an overhead transmission line, which comprises a signal acquisition module, an operational amplifier circuit and a single-end-to-differential circuit;

the signal acquisition module is used for acquiring a current signal of the power transmission line and converting the current signal into a voltage signal;

the operational amplifier circuit is used for receiving the voltage signal of the signal acquisition unit, amplifying the voltage signal in phase and converting the voltage signal into an in-phase amplified voltage signal;

the single-ended to differential circuit is used for receiving the in-phase amplified voltage signal and converting the in-phase amplified voltage signal into a differential signal.

In one embodiment, the signal acquisition module comprises: a Rogowski coil;

the Rogowski coil is used for inducing current passing through the power transmission line to obtain a voltage signal and transmitting the voltage signal to the operational amplifier circuit.

In one embodiment the fault detection device comprises: an ADC chip;

the ADC chip is used for receiving the differential signal of the single-end-to-differential circuit and converting the differential signal into a digital signal.

In one embodiment the fault detection device comprises: an FPGA chip, a high-frequency crystal oscillator;

the FPGA chip is used for receiving the digital signals of the ADC chip at a high speed in cooperation with the high-frequency crystal oscillator.

In one embodiment the fault detection device comprises: a single chip microcomputer;

the singlechip is used for receiving the digital signals transmitted by the FPGA chip and analyzing the signals.

In one embodiment the fault detection device comprises: a GPS module;

and the GPS module transmits the GPS positioning signal to the singlechip.

In one embodiment the fault detection device comprises:

the single-ended to differential circuit is an AD8138 chip.

A second aspect of the present application provides a distributed fault detection system for an overhead transmission line, comprising:

a fault detection device and an upper computer;

the fault detection device is in communication connection with an upper computer;

the fault detection device may comprise any one of the above structures;

the fault detection device comprises at least two fault detection devices;

the fault detection devices are respectively arranged at two ends of one or more power transmission lines.

In one embodiment the fault detection device comprises: a temperature and humidity sensor;

the temperature and humidity sensor detects temperature and humidity information around the acquisition point, converts the information into voltage signals and transmits the voltage signals to the single chip microcomputer, the single chip microcomputer analyzes the voltage signals and packages the voltage signals to an upper computer, the upper computer displays results, and the upper computer can be triggered to perform early warning when the ambient temperature or the ambient humidity of the fault detection device is too high.

And the GPS module is in communication connection with the FPGA and is used for synchronizing the time of each fault detection device.

The technical scheme provided by the application can comprise the following beneficial effects:

in the fault diagnosis of the power transmission line, when a power frequency current sensor and a high-frequency current sensor input collected voltage signals into a collection plate, the voltage signals are amplified in a collection plate to enhance the driving capability, and then single-ended signals are converted into differential signals through a single-ended to differential circuit, which is different from the transmission method of a signal line and a ground line of common signals, the differential signals are transmission signals on the two lines, the two signals have the same amplitude and opposite phases, so that the anti-interference capability of the signals can be enhanced, and the electromagnetic interference can be effectively inhibited. The differential signals enter the ADC chip to be converted from analog signals into digital signals, and the digital signals can be better restored into original signals after being interfered in the transmission process.

According to the technical scheme, temperature and humidity sensors can detect and acquire temperature and humidity information of the periphery of the board, the information is transmitted to the single chip microcomputer, the information is transmitted to the upper computer after being arranged by the single chip microcomputer, and the upper computer sends out early warning if the temperature is too high or the humidity is large through analysis of the upper computer, so that the board is prevented from being damaged.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

The foregoing and other objects, features and advantages of the application will be apparent from the following more particular descriptions of exemplary embodiments of the application, as illustrated in the accompanying drawings wherein like reference numbers generally represent like parts throughout the exemplary embodiments of the application.

FIG. 1 is a block diagram of a distributed fault detection system shown in an embodiment of the present application;

fig. 2 is a schematic diagram illustrating fault location according to an embodiment of the present application.

Detailed Description

Preferred embodiments of the present application will be described in more detail below with reference to the accompanying drawings. While the preferred embodiments of the present application have been illustrated in the accompanying drawings, it should be understood that the present application may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and/or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

It should be understood that although the terms "first," "second," "third," etc. may be used herein to describe various information, these information should not be limited to these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present application. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

In order to solve the above problem, an embodiment of the present application provides a distributed fault detection apparatus for an overhead transmission line, which enhances interference immunity of a transmission signal in a signal transmission process.

The technical solutions of the embodiments of the present application are described in detail below with reference to the accompanying drawings.

The Rogowski coil surrounds the power transmission line, the Rogowski coil generates induced electromotive force through a magnetic field generated by current flowing of the induction cable, corresponding quantitative analysis can be performed on the current through metering of the induced electromotive force, the induced electromotive force and the current are in a direct proportion relation, and the induced electromotive force is input into the distributed fault detection device to form a voltage signal.

The Rogowski coil can be changed into a current sensor and a resistor, and can also acquire a current signal on a power transmission line and convert the current signal into a voltage signal.

Because the electromotive force induced by the rogowski coil is small and can be easily interfered, a voltage signal needs to be input into the operational amplifier circuit to be amplified in phase, and an amplified voltage signal in phase is obtained.

The in-phase amplified voltage signal enters a single-end to differential circuit, in the single-end to differential circuit, the voltage signal firstly passes through a first half part circuit to obtain two in-phase signals with the output of the original amplitude of 1/2, and then in a second half part circuit, the two signals are converted into an in-phase signal with the original amplitude of 1/2 and a reverse signal with the original amplitude of 1/2. Different from the transmission method of one signal wire and one ground wire of common signals, the differential signals are transmission signals on the two wires, the two signals have the same amplitude and opposite phases, so that the anti-interference capability of the signals can be enhanced, and the electromagnetic interference can be effectively inhibited.

In reality, MCP6D11 chips, AD8138 chips, AD8132 chips, etc. are generally used to perform single-end to differential signal conversion.

The differential signal is converted into a digital signal through the ADC chip, and the digital signal can be easily recovered when being interfered, so that the differential signal also has certain anti-interference capability.

Digital signals can be acquired at a high speed by matching the FPGA chip with the high-frequency crystal oscillator, the FPGA has a communication high-speed interface design and can be used for high-speed signal processing, generally, if the AD sampling rate is high and the data rate is high, the FPGA is required to process the data, and the frequency of the acquired signals is improved.

After the FPGA chip processes the digital signals, the signals are packaged and sent to the single chip microcomputer, the single chip microcomputer analyzes the digital signals, and analysis results are sent to an upper computer to be displayed.

The distributed fault detection device is also provided with a GPS positioning system, the GPS module sends GPS position information to the single chip microcomputer, and the single chip microcomputer sends the GPS positioning information to the upper computer to obtain the position information of the distributed fault detection device.

The Rogowski coil induces a current signal of a power transmission line, and converts the current signal into a voltage signal, the voltage signal is possibly too small, the signal transmission effect is influenced, the voltage signal needs to be amplified in phase through an operational amplifier circuit, the driving capability of the voltage signal is enhanced, the single-ended signal is converted into a differential signal through a single-ended to differential circuit, the method is different from the transmission method of one signal wire and one ground wire of a common signal, the differential signal has transmission signals on the two wires, the amplitude of the two signals is the same, the phase is opposite, the anti-interference capability of the signals can be enhanced, and the electromagnetic interference is effectively inhibited. The differential signals are converted from analog signals into digital signals through the ADC chip, the digital signals are collected by the FPGA chip at a high speed and are sent to the single chip microcomputer, and the single chip microcomputer packs the received signals and GPS positioning information and sends the signals to the upper computer.

In the second embodiment, a distributed fault detection method for a power transmission line is described below.

Distributed fault detection device structure as above shows to distributed fault detection device still includes, temperature and humidity sensor can convert distributed fault detection device's humiture information into voltage signal, with voltage signal input singlechip, and the singlechip sends the host computer after with the voltage signal analysis of temperature and humidity sensor transmission and shows, and the host computer will send out the early warning if high temperature or humidity is too high, prevents that distributed fault detection device from being destroyed.

The distributed fault detection system of the overhead transmission line further comprises an upper computer and at least two distributed fault detection devices, wherein the two distributed fault detection devices are arranged at two ends of one transmission line.

The GPS positioning system can also send pulse per second to the FPGA chip of each distributed fault detection device, so that the time of each distributed fault detection device is synchronized, and the synchronized time is transmitted to the upper computer.

The upper computer obtains the operation power frequency current of the transmission line according to the information transmitted by the single chip microcomputer, if lightning stroke faults (lightning shielding failure and lightning counterattack) or non-lightning stroke faults (tree barriers, mountain fire, hanging objects, windage yaw and ice coating) exist on the current transmission line, the upper computer can compare the current fault waveform characteristics with the typical fault waveform characteristics in the database, diagnose the fault type and display the fault type on an upper computer interface.

The upper computer can judge the fault position according to the fault position of the power transmission line, the time of the fault information received by the fault detection devices on the two sides and the distance between the two fault detection devices.

The traveling wave double-end ranging principle is adopted: when a line fails, a high-frequency traveling wave signal is generated, the traveling wave signal is transmitted from a failure point to two ends along a wire, the traveling wave signal is installed at monitoring terminals at two ends of the line, the initial traveling wave of the failure is collected, and wave head time is measured, calculated and recorded. The time difference of the two traveling wave heads can be obtained through calculation, and the position of a fault point can be calculated under the condition that the line length and the traveling wave speed between two monitoring points of the line are known.

The temperature and humidity of the fault detection device are collected through a temperature and humidity sensor, and are transmitted to an upper computer for displaying through analysis of a single chip microcomputer, and when the temperature is too high or the humidity is too high, the upper computer can send out early warning to prevent the fault detection device from being damaged; obtaining a fault waveform when the transmission line has a fault by the upper computer according to the operating power frequency current of the transmission line obtained by the fault detection device, comparing the current fault waveform characteristics with typical fault waveform characteristics in a database, diagnosing the fault type and displaying the fault type on an interface of the upper computer; and the distance between the fault detection devices at two ends of the power transmission line is obtained through the position information sent by the GPS module, the time difference between the fault point of the power transmission line and the fault detection device is obtained through the pulse per second sent by the GPS module, and finally the fault position is positioned through the traveling wave double-end distance measurement principle.

Claims

1. A distributed fault detection device for an overhead transmission line, comprising: the circuit comprises a signal acquisition module, an operational amplifier circuit and a single-end to differential circuit;

2. A distributed fault detection device for an overhead transmission line according to claim 1, wherein the signal acquisition module comprises: a Rogowski coil;

3. A distributed fault detection device for an overhead transmission line according to claim 2, comprising: an ADC chip;

4. A distributed fault detection device for an overhead transmission line according to claim 3, comprising: an FPGA chip, a high-frequency crystal oscillator;

the FPGA chip is used for matching with the high-frequency crystal oscillator to receive the digital signal of the ADC chip at a high speed.

5. A distributed fault detection device for an overhead transmission line according to claim 4, characterized in that it comprises: a single chip microcomputer;

6. A distributed fault detection device for an overhead transmission line according to claim 5, comprising: a GPS module;

and the GPS module transmits the GPS positioning signal to the singlechip.

7. A distributed fault detection device for an overhead transmission line according to claim 1, characterized in that it comprises:

the single-ended to differential circuit is an MCP6D11 chip.

8. A distributed fault detection system for an overhead transmission line, comprising:

the distributed fault detection device of the overhead transmission line and the upper computer according to any one of claims 1 to 7, wherein the distributed fault detection device is connected with the upper computer in a communication way.