CN213581212U

CN213581212U - Secondary side voltage sampling overhead distribution line fault positioning system

Info

Publication number: CN213581212U
Application number: CN202022807124.4U
Authority: CN
Inventors: 王勃; 阎恩; 董倩; 魏洪文; 于琳琳; 张立斌
Original assignee: Shandong Bohong Electric Co ltd
Current assignee: Shandong Bohong Electric Co ltd
Priority date: 2020-11-27
Filing date: 2020-11-27
Publication date: 2021-06-29
Anticipated expiration: 2030-11-27

Abstract

The utility model relates to a secondary side voltage sample distribution lines fault locating system that makes somebody a mere figurehead belongs to electric power system intelligent monitoring equipment field. Including built on stilts distribution lines and voltage sampling terminal, its characterized in that: the voltage sampling terminals are distributed on the voltage transformation secondary side of the overhead distribution line; the voltage sampling terminal comprises a voltage sensor, a signal modulator, a CPU and a communication unit which are connected through a circuit, and a trigger logic module and an FPGA are arranged between the signal modulator and a data end of the CPU. The utility model discloses a distribution lines transient state signal in gathering substation equipment secondary side line mould voltage has realized distribution overhead line's failure diagnosis and fault point's accurate positioning.

Description

Secondary side voltage sampling overhead distribution line fault positioning system

Technical Field

The utility model relates to a secondary side voltage sample distribution lines fault locating system that makes somebody a mere figurehead belongs to electric power system intelligent monitoring equipment field.

Background

In a power distribution network power supply system, an overhead line is an important component, the safe and efficient operation of the whole power system is directly influenced, the network structure of the power distribution overhead line is complex, and the occurrence frequency of grounding and short-circuit faults is high. The traditional fault finding mode is time-consuming and labor-consuming, the manual line patrol is far, and the workload is large; the off-line fault test equipment needs to be powered off to search fault points, so that normal production and life are influenced, the on-line monitoring and fault location of the power distribution overhead line are effectively implemented, and the reliability and the economical efficiency of the operation of the power distribution overhead line are important subjects faced by power supply enterprises at present.

Distribution network automation has improved power supply reliability and power supply quality greatly, shortens the accident handling time, reduces the power failure scope, but present distribution terminal (FTU/DTU/TTU) -generally dispose in switch or transformer position, lack the management and control to the interlude of long distance overhead distribution lines. When the transmission distance of a distribution line is long, the number of line branches is large, the running condition is complex, and the environment and weather conditions are severe, line short circuit and ground fault caused by natural disasters such as external damage, equipment fault, thunder and lightning often occur, and in addition, a fault section (position) is difficult to determine during fault, great difficulty is brought to maintenance work, and particularly, in remote areas, the time and labor are wasted when the fault section is searched.

At present, although some methods exist to solve the problem of monitoring line alarm, the effect is not ideal, and many problems exist, and the specific situations are as follows:

1. most electric wire netting all utilize the trouble sign to report to the police to overhead line trouble, but overhead type line fault indicator all judges alone, shows alone and reports to the police, can't realize the real time monitoring of circuit, must cooperate the manual work to patrol the line after the circuit goes wrong and just can confirm the fault location, patrols line work load very big, and troubleshooting difficulty and location are not rapid moreover, have influenced normal production life.

2. The existing scheme does not have the characteristics of safe communication, and generally adopts a non-networking mode or networking through a GPRS public network. The non-networking mode is the most widely used at present due to flexible deployment and simple installation, but the non-networking mode cannot realize centralized management, needs manual cooperation and cannot realize real-time monitoring, and is gradually quitted from being used at present; at present, as a substitute of a non-networking mode, a system networking through a GPRS public network is implemented gradually, but in view of gradual service stop of a GPRS network operator, part of the system networking is replaced by using the Internet of things, but the networking mode has network layer potential safety hazards and application layer potential safety hazards.

3. The existing fault discrimination methods including the discrimination methods of a zero sequence power method, a first half wave method, a wavelet transformation method, an injection signal method and the like generally have the problems of low judgment precision and easy generation of erroneous judgment and missed judgment due to low sampling rate and low time keeping precision.

SUMMERY OF THE UTILITY MODEL

According to the deficiency in the above prior art, the utility model discloses the problem that solves is: the secondary side voltage sampling overhead distribution line fault positioning system can be installed and used without power failure, is safe and simple, and is accurate in positioning.

The technical scheme adopted by the invention for solving the technical problems is as follows: the utility model provides a secondary side voltage sample overhead distribution lines fault locating system, includes overhead distribution lines and voltage sampling terminal, its characterized in that: the voltage sampling terminals are distributed on the voltage transformation secondary side of the overhead distribution line; the voltage sampling terminal comprises a voltage sensor, a signal modulator, a CPU and a communication unit which are connected through a circuit, and a trigger logic module and an FPGA are arranged between the signal modulator and a data end of the CPU.

The voltage sampling terminal is only required to be arranged on a binding post on the secondary side of the user transformer, the traveling wave signal of the line mode voltage is transmitted to the CPU for processing through the signal modulator, and the processing result is transmitted or displayed through the communication unit. The line mode voltage is characterized in that: 1. the method has the advantages of high response speed, clear transient characteristics, high distance measurement precision and the like, and can realize accurate positioning by utilizing the arrival time of the voltage traveling wave at the secondary side of the line or the transformer in a distributed manner. 2. And in contact installation, a special high-frequency voltage sensor is adopted to realize double-end distance measurement. 3. The attenuation coefficient of high-frequency components is small, and the method is suitable for ultra-long distance lines. 4. The mounting structure of the overhead line has no influence on the success rate of the test. Because the at least more than 2 voltage sampling terminals are installed in a distributed mode, the traveling wave double-end ranging technology is utilized for analysis, the method has the advantages of simplicity, reliability, wide applicability and easiness in implementation, and the accurate positioning of line faults can be realized.

The preferable scheme is as follows:

and the voltage sensor is fixed on a voltage transformation secondary side outlet wire of the overhead distribution line. The voltage sensor is a contact electronic voltage transformer.

The signal modulator is connected with the input end of the trigger logic module through an AD converter. Depending on the data of the processing unit, the signal may be analog or digital.

The communication unit arranged on the CPU at least comprises one of a network card, a USB, a 4G/5G communication chip, an SPI/RS232 chip or an input/output interface. And more than two interconnected devices are realized, or data exchange is realized with an upper computer server or a cloud data terminal.

The CPU is provided with a power module, and the power module at least comprises one of a battery, a storage battery, a solar panel or an induction generating device.

The shell is one of a fully cast aluminum shell, a stainless steel shell or a carbon steel shell coated with fluorine paint. Protects electronic components and realizes the shielding of electromagnetic interference.

The utility model discloses the beneficial effect who has is: the method is characterized in that the operation state of the overhead line is monitored for 6kV \10kV \35kV, a voltage sensor is utilized to collect transient traveling wave signals in the operation process of the overhead line, the transient traveling wave signals are analyzed and processed, the insulation state on-line monitoring of the overhead line is realized, a distance measuring device adopts a modern traveling wave double-end distance measuring technology to realize accurate positioning of fault points, a reliable basis is provided for the fault finding of the overhead distribution line, the wireless communication technology is utilized to report maintenance and operation and maintenance personnel, the purposes of quick maintenance and fault repair are achieved, and the accident expansion and unnecessary economic loss are avoided. The system installation does not change the operation mode and structure of the overhead distribution line and does not stop the power supply. And the software background adopts a GIS map to display the position of a fault point, and a management interface is simple and easy to operate.

The utility model discloses an adopt the line mould voltage signal of substation equipment secondary side to change and catch distribution lines transient state process, the high accuracy is technique of keeping watch on in step, has realized distribution overhead line's failure diagnosis and the accurate positioning of fault point.

Drawings

Fig. 1 is a schematic view of the installation structure of the present invention;

FIG. 2 is a schematic block diagram of a voltage sampling terminal according to the present invention;

fig. 3 is a schematic diagram of a low-frequency voltage acquisition circuit for conditioning a voltage sampling signal according to the present invention;

fig. 4 is a high-frequency voltage acquisition circuit diagram for voltage acquisition signal conditioning according to the present invention;

fig. 5 is a schematic circuit diagram of an AD converter according to the present invention.

Wherein, 1, an overhead distribution line; 2. a voltage transformation device; 3. a secondary side terminal; 4. and a voltage sampling terminal.

Detailed Description

Embodiments of the present invention are further described below with reference to the accompanying drawings:

example 1:

as shown in fig. 1 and fig. 2, the secondary side voltage sampling overhead distribution line fault positioning system comprises an overhead distribution line 1 and a plurality of voltage sampling terminals 4, wherein the voltage sampling terminals 4 are distributed on the secondary side of a transformer of the overhead distribution line 1; the voltage sampling terminal comprises a voltage sensor, a signal modulator, a CPU and a communication unit which are connected through a circuit, and a trigger logic module and an FPGA are arranged between the signal modulator and a data end of the CPU.

The signal modulator is connected with the input end of the trigger logic module through the AD converter. Depending on the data of the processing unit, the signal may be analog or digital. The communication unit arranged on the CPU at least comprises one of a network card, a USB, a 4G/5G communication chip, an SPI/RS232 chip or an input/output interface. And more than two interconnected devices are realized, or data exchange is realized with an upper computer server or a cloud data terminal. The CPU is provided with a power module, and the power module at least comprises one of a battery, a storage battery, a solar panel or an induction generating device.

The voltage sampling terminal is provided with a shell, and the shell is one of a fully cast aluminum shell, a stainless steel shell or a carbon steel shell coated with fluorine paint. Protects electronic components and realizes the shielding of electromagnetic interference.

As shown in fig. 3-5, after obtaining a voltage signal, the low voltage measurement transformer converts the voltage signal through a transformer U20, performs voltage stabilization and isolation direct current-direct current input, modulates the voltage signal through signal amplifiers U21 and U19, inputs the modulated voltage signal into an AD converter U22 for conversion, and inputs the converted voltage signal into a CPU for processing. The high-frequency voltage signal enters an operational amplifier U24 and an isolation capacitor C149 and is input into a conversion transformer L16, and is input into an AD converter U22 after being subjected to voltage division. The AD converter U22 and its peripheral circuits complete the signal conversion of the system for input to the CPU for processing.

Experiments prove that the utility model can realize the accurate positioning of the fault point within 30 seconds; the positioning precision is +/-6 m.

The present invention is not limited to the above embodiments, and variations, modifications, additions and substitutions which can be made by a person skilled in the art within the scope of the invention should also belong to the protection scope of the present invention.

Claims

1. The utility model provides a secondary side voltage sample overhead distribution lines fault locating system, includes overhead distribution lines and voltage sampling terminal, its characterized in that:

the voltage sampling terminals are distributed on the voltage transformation secondary side of the overhead distribution line;

the voltage sampling terminal comprises a voltage sensor, a signal modulator, a CPU and a communication unit which are connected through a circuit, and a trigger logic module and an FPGA are arranged between the signal modulator and a data end of the CPU.

2. The secondary side voltage sampling overhead distribution line fault location system of claim 1, wherein: and the voltage sensor is fixed on a voltage transformation secondary side outlet wire of the overhead distribution line.

3. The secondary side voltage sampling overhead distribution line fault location system of claim 2, wherein: the voltage sensor is a contact electronic voltage transformer.

4. The secondary side voltage sampling overhead distribution line fault location system of claim 2, wherein: the voltage sensor is a non-contact polar plate capacitance measuring sensor.

5. The secondary side voltage sampling overhead distribution line fault location system of claim 1, wherein: the signal modulator is connected with the input end of the trigger logic module through an AD converter.

6. The secondary side voltage sampling overhead distribution line fault location system of claim 1, wherein: the communication unit arranged on the CPU at least comprises one of a network card, a USB, a 4G/5G communication chip, an SPI/RS232 chip or an input/output interface.

7. The secondary side voltage sampling overhead distribution line fault location system of claim 1, wherein: the CPU is provided with a power module, and the power module at least comprises one of a battery, a storage battery, a solar panel or an induction generating device.

8. The secondary side voltage sampling overhead distribution line fault location system of claim 1, wherein: the shell is one of a fully cast aluminum shell, a stainless steel shell or a carbon steel shell coated with fluorine paint.

9. The secondary side voltage sampling overhead distribution line fault location system of claim 1, wherein: the FPGA is connected with the clock circuit and the positioning chip.