KR102512148B1 - Distribution line ground fault location estimation apparatus and method - Google Patents

Abstract

According to an embodiment, a first voltage and a first current are collected from a first terminal device disposed at a drawing end of a substation of a distribution line, and a first voltage and a first current are collected from a second terminal device disposed most adjacent to the drawing end side of the substation from a ground fault point. a communication unit that collects two voltages and a second current, and collects a third voltage and a third current from a third terminal device disposed closest to the load side from the ground fault point; a first calculator configured to calculate a fault current using the second current and the third current; a second calculation unit calculating a fault resistance at the ground fault point using the fault current and the second voltage; and a third calculation unit calculating a distance between the ground fault point from the lead end of the distribution line substation using the fault current, the fault resistance, the first voltage, the first current, and the impedance per unit length of the distribution line. It provides a distribution line ground fault location estimating device comprising a.

Description

Distribution line ground fault location estimation apparatus and method {Distribution line ground fault location estimation apparatus and method}

An embodiment of the present invention relates to an apparatus and method for estimating a ground fault location in a distribution line.

A ground fault refers to a situation in which electric current leaks out of a line due to a ground fault and may cause an accident such as fire, electric shock to people, or damage to electric circuits or equipment. Causes of ground faults include age-related deterioration of insulators, physical damage due to mechanical shock or insulation puncture, deterioration due to extreme transient voltage shock or normal voltage, and ground faults due to the expansion of short-circuit accidents.

When a ground fault occurs, it is necessary to quickly and accurately find the point and restore it.

Currently, a fault point detection method that calculates the distance to the fault point when a ground fault occurs on a transmission and distribution line is being actively researched recently. Since the transmission system is a three-phase balanced circuit, the fault point detection method here is a method using traveling waves, Accurate fault point detection methods such as a method using harmonic components and an apparent impedance method using fundamental wave components of voltage and current have been proposed, and currently, fault point detection devices are widely used in power transmission systems.

An object of the present invention is to provide an apparatus and method for estimating a ground fault location of a distribution line capable of accurately determining a ground fault point of a distribution line.

According to an embodiment, a first voltage and a first current are collected from a first terminal device disposed at a drawing end of a substation of a distribution line, and a first voltage and a first current are collected from a second terminal device disposed most adjacent to the drawing end side of the substation from a ground fault point. a communication unit that collects two voltages and a second current, and collects a third voltage and a third current from a third terminal device disposed closest to the load side from the ground fault point; a first calculator configured to calculate a fault current using the second current and the third current; a second calculation unit calculating a fault resistance at the ground fault point using the fault current and the second voltage; and a third calculation unit calculating a distance between the ground fault point from the lead end of the distribution line substation using the fault current, the fault resistance, the first voltage, the first current, and the impedance per unit length of the distribution line. It provides a distribution line ground fault location estimating device comprising a.

According to an embodiment, the step of collecting the first voltage and the first current from the first terminal device disposed at the drawing end of the distribution line substation by the communication unit; collecting, by the communication unit, a second voltage and a second current from a second terminal device disposed closest to the substation lead-out side from the ground fault point; collecting, by the communication unit, a third voltage and a third current from a third terminal device disposed closest to the load side from the ground fault point; calculating a fault current by a first calculation unit using the second current and the third current; calculating, by a second calculator, a fault resistance of the ground fault point using the fault current and the second voltage; and calculating, by a third operation unit, a distance between the ground fault point from a lead end of the distribution line substation using the fault current and the fault resistance.

According to an embodiment, a computer-readable recording medium in which a program for executing the above-described method is recorded on a computer is provided.

The apparatus and method for estimating the ground fault location of the distribution line according to the present invention can accurately determine the ground fault location of the distribution line.

1 is a diagram for explaining a power distribution automation system according to an embodiment.
2 is a configuration block diagram of an apparatus for estimating a ground fault location of a distribution line according to an embodiment.
3 is a diagram for explaining the operation of the distribution line ground fault location estimating device according to the embodiment.
4 is a flowchart of a method for estimating a ground fault location in a distribution line according to an embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

However, the technical idea of the present invention is not limited to some of the described embodiments, but may be implemented in a variety of different forms, and if it is within the scope of the technical idea of the present invention, one or more of the components among the embodiments can be selectively implemented. can be used by combining and substituting.

In addition, terms (including technical and scientific terms) used in the embodiments of the present invention, unless explicitly specifically defined and described, can be generally understood by those of ordinary skill in the art to which the present invention belongs. It can be interpreted as meaning, and commonly used terms, such as terms defined in a dictionary, can be interpreted in consideration of contextual meanings of related technologies.

Also, terms used in the embodiments of the present invention are for describing the embodiments and are not intended to limit the present invention.

In this specification, the singular form may also include the plural form unless otherwise specified in the phrase, and when described as "at least one (or more than one) of A and (and) B and C", A, B, and C are combined. may include one or more of all possible combinations.

Also, terms such as first, second, A, B, (a), and (b) may be used to describe components of an embodiment of the present invention.

These terms are only used to distinguish the component from other components, and the term is not limited to the nature, order, or order of the corresponding component.

In addition, when a component is described as being 'connected', 'coupled' or 'connected' to another component, the component is not only directly connected to, combined with, or connected to the other component, but also with the component. It may also include the case of being 'connected', 'combined', or 'connected' due to another component between the other components.

In addition, when it is described as being formed or disposed on the "top (above) or bottom (bottom)" of each component, the top (top) or bottom (bottom) is not only a case where two components are in direct contact with each other, but also one A case in which another component above is formed or disposed between two components is also included. In addition, when expressed as "up (up) or down (down)", it may include the meaning of not only an upward direction but also a downward direction based on one component.

Hereinafter, the embodiments will be described in detail with reference to the accompanying drawings, but the same or corresponding components regardless of reference numerals are given the same reference numerals, and overlapping descriptions thereof will be omitted.

1 is a diagram for explaining a power distribution automation system according to an embodiment. The distribution automation system 1 is a system for improving power supply reliability by comprehensively monitoring distribution lines. The distribution automation system 1 may monitor and measure field information of various switchgear and distribution facilities installed in a distribution line through a terminal device for distribution automation, and provide the information to the main device 10 in real time.

Referring to FIG. 1, the distribution automation system 1 remotely controls equipment 30 such as a circuit breaker, switchgear, recloser, etc. installed in a distribution line, a terminal device 20 for distribution automation, and a distribution automation equipment 30 in an operating room. It may be configured as a main device 10 for monitoring and controlling. The distribution automation system 1 acquires various data of distribution lines from the terminal device 20 for distribution automation installed in the field by data communication between the main device 10 and a communication device (not shown) and uses it to control the distribution system. can be supervised.

The distribution automation terminal device 20 measures the current and voltage flowing in the distribution line, detects the state in the event of a distribution line accident, transmits it to the main device 10, or controls the facility according to a command received from the main device 10. functions can be performed. At this time, data transmitted from the terminal device 20 for distribution automation may be transmitted to the main device 10 through a front-end processor (FEP), which is a middle layer. The distribution automation terminal device 20 may perform a data measurement and data transmission function of the distribution automation system 1 to the main device 10, a reporting function when an event occurs, and a function of detecting and controlling the opening and closing of the facility 30. . Data collected from the distribution automation terminal device 20 may be transmitted to the main device 10 via a terminal side communication device (not shown) and a main device side communication device (not shown).

2 is a configuration block diagram of an apparatus for estimating a ground fault location of a distribution line according to an embodiment. The distribution line ground fault location estimating device 100 according to the embodiment may be implemented in a main unit or as a separate device.

Referring to FIG. 2 , the distribution line ground fault location estimation apparatus 100 according to the embodiment may include a communication unit 110, a first operation unit 120, a second operation unit 130, and a third operation unit 140. .

The communication unit 110 collects a first voltage and a first current from a first terminal device disposed at a drawing end of a substation of a distribution line, and collects a first voltage and a first current from a second terminal device disposed most adjacent to a drawing end side of a substation from a ground fault point. The voltage and the second current may be collected, and the third voltage and the third current may be collected from a third terminal device disposed closest to the load side from the ground fault point.

The communication unit 110 may periodically perform data communication with each terminal device disposed on the distribution line. When it is determined that a ground fault has occurred in the distribution line, the communication unit 110 includes a first terminal device disposed at the outgoing end of the substation, a second terminal device disposed closest to the ground fault point and disposed toward the substation outgoing end, and the closest to the ground fault point. Voltage and current measurement data may be collected from a third terminal device disposed adjacent to the load side.

The communication unit 110 may receive ground fault occurrence information from a main device or a terminal device.

The first calculation unit 120 may calculate the fault current using the second current and the third current. The fault current may refer to a current flowing to the ground through a ground fault point.

The first calculation unit 120 may calculate the fault current according to Equation 1 below.

In Equation 1, I _f is a fault current, I ₁ is a first current, and I ₃ may mean a third current. In the embodiment, I ₁ may mean the first current for the A phase, and I ₃ may mean the third current for the A phase. In the embodiment, the description is based on the current and voltage of phase A, but the fault current and fault resistance can be calculated using the current and voltage of phase B or C according to the ground fault occurrence situation.

The second calculator 130 may calculate the fault resistance of the ground fault point using the fault current and the second voltage. The fault resistance may refer to resistance across the entire ground fault line from the point where the ground fault occurs to the ground.

The second calculator 130 may calculate the fault resistance according to Equation 2 below.

In Equation 2, R _f is a fault resistance, V ₂ is a second voltage, and I _f may mean a fault current. In an embodiment, V ₂ may mean the second voltage for the A phase.

The third arithmetic unit 140 may calculate the distance between the ground fault point from the lead end of the distribution line substation using the fault current, fault resistance, first voltage, first current, and impedance per unit length of the distribution line.

The third calculation unit 140 may calculate the distance between the ground fault points from the draw end of the distribution line substation according to Equation 3 below.

In Equation 3, d is the distance from the lead end of the distribution substation to the ground fault point, z is the impedance per unit length of the distribution line, V ₁ is the first voltage, I ₁ is the first current, and I _f is a fault current, and R _f may mean a fault resistance.

3 is a diagram for explaining the operation of the distribution line ground fault location estimating device according to the embodiment.

Referring to FIGS. 2 and 3 , it can be confirmed that a ground fault has occurred between the second terminal device G1 and the third terminal device G2. The communication unit 110 collects voltage and current data from the first terminal device G0 of the substation draw-out and the second terminal device G1 and the third terminal device G2 disposed adjacent to the ground fault point F. can do.

The first operation unit 120 may calculate the fault current by subtracting the third current flowing through the third terminal device from the second current flowing through the first terminal device G0 and the second terminal device G1.

Also, the second arithmetic unit 130 may calculate the fault resistance of the ground fault point using the fault current calculated by the first arithmetic unit 120 and the second voltage applied to the second terminal device G1.

In addition, the third arithmetic unit 140 uses the fault current calculated by the first arithmetic unit 120 and the fault resistance calculated by the second arithmetic unit 130 to determine the distance between the ground fault point F from the draw end of the substation of the distribution line. (d) can be computed.

4 is a flowchart of a method for estimating a ground fault location in a distribution line according to an embodiment.

Referring to FIG. 4 , first, the communication unit may collect a first voltage and a first current from a first terminal device disposed at a drawing terminal of a distribution line substation (S401).

Next, the communication unit may collect the second voltage and the second current from the second terminal device disposed most adjacent to the substation draw-out side from the ground fault point (S402).

Next, the communication unit may collect a third voltage and a third current from a third terminal device disposed closest to the load side from the ground fault point (S403).

The process of collecting data from the first terminal device to the third terminal device by the communication unit may be performed in a sequential relationship or concurrently.

Next, the first calculation unit may calculate the fault current using the second current and the third current (S404).

Next, the second calculation unit may calculate the fault resistance of the ground fault point using the fault current and the second voltage (S405).

Next, the third operation unit may calculate the distance between the ground fault point and the lead end of the distribution substation using the fault current, fault resistance, first voltage, first current, and impedance per unit length of the distribution line (S406 ).

When a ground fault occurs, the exact fault current and fault resistance must be known in order to accurately calculate the ground fault occurrence point. Conventionally, a method of estimating a ground fault occurrence point using only a fault current of a distribution line or determining a ground fault occurrence point by estimating a fault resistance of 0 to 30 [Ω] has been used. However, this method has a problem in that an exact ground fault point cannot be determined.

An apparatus and method for estimating the ground fault location of a distribution line according to an embodiment collects the voltage and current of a substation draw-out terminal and the voltage and current adjacent to a ground fault occurrence point, calculates an accurate fault current and fault resistance, and determines an accurate fault point therefrom. There is a technical effect that can be done.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer readable recording medium. In this case, the medium may continuously store a program executable by a computer or temporarily store the program for execution or download. In addition, the medium may be various recording means or storage means in the form of a single or combined hardware, but is not limited to a medium directly connected to a certain computer system, and may be distributed on a network. Examples of the medium include magnetic media such as hard disks, floppy disks and magnetic tapes, optical recording media such as CD-ROM and DVD, and magneto-optical media such as floptical disks. , and ROM, RAM, flash memory, etc. configured to store program instructions. In addition, examples of other media include “recording media” or storage media managed by an app store that distributes applications, a site that supplies or distributes various other software, and a server.

The term '~unit' used in this embodiment means software or a hardware component such as a field-programmable gate array (FPGA) or ASIC, and '~unit' performs certain roles. However, '~ part' is not limited to software or hardware. '~bu' may be configured to be in an addressable storage medium and may be configured to reproduce one or more processors. Therefore, as an example, '~unit' refers to components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. Functions provided within components and '~units' may be combined into smaller numbers of components and '~units' or further separated into additional components and '~units'. In addition, components and '~units' may be implemented to play one or more CPUs in a device or a secure multimedia card.

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art will variously modify and change the present invention within the scope not departing from the spirit and scope of the present invention described in the claims below. You will understand that it can be done.

1: Distribution automation system
10: main unit
20: terminal device for distribution automation
30: distribution automation equipment
100: distribution line ground fault location estimation device
110: communication department
120: first calculation unit
130: second calculation unit
140: third operation unit

Claims (9)

A first voltage and a first current are collected from a first terminal device disposed at a lead end of a substation of a distribution line, and a second voltage and a second current are collected from a second terminal device disposed most adjacent from a ground fault point toward the lead end side of the substation. a communication unit that collects current and collects a third voltage and a third current from a third terminal device disposed most adjacent to the load side from the ground fault point;
a first calculator configured to calculate a fault current using the second current and the third current;
a second calculation unit calculating a fault resistance at the ground fault point using the fault current and the second voltage; and
And a third calculation unit for calculating a distance between the ground fault point from the lead end of the distribution line substation using the fault current, the fault resistance, the first voltage, the first current, and the impedance per unit length of the distribution line. but
Wherein the communication unit receives ground fault occurrence information from at least one of the first terminal device, the second terminal device, and the third terminal device.
According to claim 1,
The first calculation unit calculates the fault current according to Equation 1 below.
[Equation 1]

(In Equation 1, I _f is the fault current, I ₁ is the first current, and I ₃ is the third current)
According to claim 2,
The second calculation unit calculates the fault resistance according to Equation 2 below.
[Equation 2]

(In Equation 2, R _f is the fault resistance, V ₂ is the second voltage, and I _f is the fault current)
According to claim 3,
The third calculation unit calculates the distance between the ground fault points from the lead end of the distribution line substation according to Equation 3 below.
[Equation 3]

(In Equation 3, d is the distance from the lead end of the distribution substation to the ground fault point, z is the impedance per unit length of the distribution line, V ₁ is the first voltage, I ₁ is the first current, I _f is the fault current and R _f is the fault resistance)
Collecting, by a communication unit, a first voltage and a first current from a first terminal device disposed at a drawing end of a substation of a distribution line;
collecting, by the communication unit, a second voltage and a second current from a second terminal device disposed closest to the substation lead-out side from the ground fault point;
collecting, by the communication unit, a third voltage and a third current from a third terminal device disposed closest to the load side from the ground fault point;
calculating a fault current by a first calculation unit using the second current and the third current;
calculating, by a second calculator, a fault resistance of the ground fault point using the fault current and the second voltage; and
Calculating, by a third operation unit, a distance between the ground fault point from the lead end of the distribution line substation using the fault current, the fault resistance, the first voltage, the first current, and the impedance per unit length of the distribution line Including,
receiving, by the communication unit, ground fault occurrence information from at least one of the first terminal device, the second terminal device, and the third terminal device;
Distribution line ground fault location estimation method further comprising a.
According to claim 5,
The first calculation unit calculates the fault current according to Equation 4 below.
[Equation 4]

(In Equation 4, I _f is the fault current, I ₁ is the first current, and I ₃ is the third current)
According to claim 6,
The second calculation unit calculates the fault resistance according to Equation 5 below.
[Equation 5]

(In Equation 5, R _f is the fault resistance, V ₂ is the second voltage, and I _f is the fault current)
According to claim 7,
The third calculation unit calculates the distance between the ground fault points from the draw end of the distribution line substation according to Equation 7 below.
[Equation 6]

(In Equation 6, d is the distance from the draw end of the distribution substation to the ground fault point, z is the impedance per unit length of the distribution line, V ₁ is the first voltage, I ₁ is the first current, I _f is the fault current and R _f is the fault resistance)
A computer-readable recording medium on which a program for executing the method of any one of claims 5 to 8 is recorded on a computer.

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