JP2019028024A - Fault point location method, device therefor, and program - Google Patents

Abstract

To provide a fault point location method, a device therefore, and a program with which it is possible to locate a fault point in the shunt reactor installation section of a power transmission line buried in the ground.SOLUTION: Provided is a fault point location method, with a shunt reactor installed, for locating a fault point in the shunt reactor installation section of a power transmission line buried in the ground, comprising: an acquisition step for acquiring an own edge voltage, an other edge voltage, an own edge current, an other edge current, an own edge reactor current, and an other edge reactor current; and a computation step for calculating the ratio of entire line impedance of the power transmission line to the line impedance to the fault point. The computation step calculates said ratio on the basis of the own edge voltage, other edge voltage, own edge current, other edge current, own edge reactor current, and other edge reactor current acquired in the acquisition step.SELECTED DRAWING: Figure 1

Description

  Embodiments described herein relate generally to a fault location device, a method, and a program for a transmission line.

  In recent years, a stable power transmission system has been demanded due to an increase in power demand. Therefore, when a failure occurs in the transmission line, it is necessary to quickly find and eliminate the failure point.

  As shown in FIG. 6, when an electrical failure occurs in a transmission line in a three-phase AC circuit, measurable self-end current I1, counterpart end current I2, end-end voltage V1, end-end voltage V2, and the known values The failure point is determined using the line impedance Kz of a certain power transmission line 101 as a whole.

  The failure point can be obtained by calculating the ratio (PU) of the total line impedance Kz of the transmission line 101 and the line impedance KzL up to the failure point.

  Here, the line impedance KzL up to the failure point is a value that cannot be measured, and is calculated from the current and voltage at each end. The concept will be described below.

  The own-end voltage V1 can be expressed by the sum of the line drop voltage VL1 up to the failure point and the failure point voltage Vf. Can be calculated (Equation (101) in FIG. 6). Here, since the failure point voltage Vf is a value that cannot be measured, KzL cannot be calculated from the equation (101).

  Therefore, when paying attention to the other end voltage V2, the other end voltage V2 can be expressed by the sum of the line drop voltage VL2 up to the failure point and the failure point voltage Vf in the same manner as the own end voltage V1. The drop voltage VL2 can be calculated by multiplying the counterpart current I2 by the difference between the total line impedance Kz and the line impedance KzL up to the failure point (formula (102) in FIG. 6).

  Here, as shown in the equation (103) of FIG. 6, when simultaneous equations are established for V1 and V2 and V2 is subtracted from V1, the failure point voltage Vf is canceled out, so that the equation (104) of FIG. Thus, the line impedance KzL up to the failure point can be calculated.

  Finally, by dividing equation (104) by Kz, a fault point orientation equation of equation (105) in FIG. 6 can be obtained. That is, a fault point location formula is obtained from the voltage difference between V1 and V2, and the fault point can be determined by calculating the ratio d of the line impedance KzL to the fault point with respect to the total line impedance Kz.

Japanese Patent Laid-Open No. 2008-261751

  The conventional fault location method can be applied in a general overhead line transmission section. However, when the transmission line is buried in the ground, the leakage current to the ground due to parasitic capacitance is larger than that of a general overhead line, and the ground leakage current is canceled out by the current of the branch reactor installed in the transmission line. Yes. In this regard, the conventional method cannot be applied to a transmission line buried in the ground because the current flowing through the branch reactor is not taken into consideration.

  The failure point locating method, the apparatus and the program according to the embodiment of the present invention have been made to solve the above-described problems, and have failed in a shunt reactor installation section of a transmission line buried in the ground. It is an object of the present invention to provide a failure point locating method, a device thereof, and a program capable of locating points.

  In order to achieve the above object, the failure point locating method of the present embodiment is a failure point locating in which a branch reactor is installed and a failure point in a section where the branch reactor is installed in a transmission line buried in the ground is determined. A method for acquiring a self-end voltage, a counterpart voltage, a self-end current, a counterpart end current, a self-end reactor current, and a counterpart end reactor current, and all line impedances and fault points of the transmission line A calculation step for calculating a ratio of line impedance, and the calculation step includes a self-end voltage, a partner end voltage, a self-end current, a partner end current, a partner end reactor current, and a partner end reactor current acquired by the acquisition step. And the ratio is calculated based on the total line impedance.

  This embodiment can also be understood as a device that realizes the function of each step described above by a computer or an electronic circuit, and a program that causes a computer to execute the process of each step described above.

It is a figure which shows the alternating current power transmission line with which the failure point location apparatus which concerns on 1st Embodiment is applied. It is a functional block diagram which shows the structure of the failure point location apparatus which concerns on 1st Embodiment. It is a figure for demonstrating a leak point concentration approximate equivalent point. It is a figure which shows the calculation process of the fault point orientation formula in case a failure arises in the end side rather than the leak point concentration approximate equivalent point. It is a functional block diagram which shows the structure of the failure point location apparatus which concerns on 2nd Embodiment. It is a figure for demonstrating the orientation formula of the failure point by a prior art.

[1. First Embodiment]
[1-1. Constitution]
Hereinafter, the failure point locating device according to the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram illustrating an AC power transmission line to which the fault location apparatus according to the present embodiment is applied.

  The power transmission line 1 is a power transmission line buried in the ground, for example, a ground cable. Branch reactors 2 a and 2 b are installed in the power transmission line 1. The transmission line end where the branch reactors 2a and 2b are installed is referred to as a self end 1a and a counterpart end 1b, and the section between the self end and the counterpart end is referred to as a branch reactor installation section.

  The power transmission line 1 is provided with a current measuring device and a voltage measuring device (not shown) such as CT and VT, and the current measuring device has its own end current, opposite end current, own end branch reactor current, and other end branch reactor current. Are measured and transmitted to the fault location device. The voltage measuring device measures the self-end voltage and the counterpart end voltage, and transmits them to the fault location device.

  The failure point locating device is connected to the current measuring device and the voltage measuring device by wire or wirelessly, and acquires the measured current value and voltage value. Specifically, this current value is a value of a self-end current, a counterpart end current, a self-end branch reactor current, or a counterpart end branch reactor current, and a voltage value is a value of the self-end voltage or the counterpart voltage.

  The failure point locating device is a device for locating a failure point in a branch reactor installation section of the transmission line 1 buried in the ground. A failure point is a point where a short circuit or a ground fault has occurred.

  FIG. 2 is a functional block diagram of the fault location apparatus according to the present embodiment. The fault location apparatus includes a storage unit 21 in which all line impedances Kz are stored in advance, an acquisition unit 22 that acquires current values and voltage values from the current measurement device and the voltage measurement device, and a physical quantity acquired from the storage unit 21 and the acquisition unit 22. And a calculation unit 23 that calculates the ratio of the total line impedance Kz of the power transmission line 1 to the line impedance KzL up to the failure point. Each of the units 21 to 23 includes a single computer or a plurality of computers connected via a network. That is, the failure point locating apparatus stores a program in an HDD, an SSD, or the like, appropriately expands in a RAM, and performs processing of each unit by being processed by a CPU.

  The acquisition unit 22 acquires values of the self-end current, the counterpart end current, the self-end branch reactor current, and the counterpart end branch reactor current from the current measurement device, and the self-end voltage and the counterpart end voltage from the voltage measurement device. Get the value of.

  The calculation unit 23 is configured to include a processor, and the total line impedance Kz of the transmission line 1 acquired from the storage unit 21, the own end current, the other end current, the own end branch reactor current, and the other end branch acquired from the acquisition unit 22. Based on the reactor current, the local voltage, and the counterpart voltage, the ratio of the total line impedance Kz of the transmission line 1 to the line impedance KzL up to the failure point is calculated.

Ｉ１：自端電流、Ｉ２：相手端電流
Ｖ１：自端電圧、Ｖ２：相手端電圧
ＩＬ１：自端リアクトル電流、ＩＬ２：相手端リアクトル電流
Ｋｚ：全線路インピーダンス
Ｋρ：漏れ電流集中近似等価点
本実施形態では、漏れ電流集中近似等価点Ｋρは、全線路インピーダンスの半分値とし、例えば０．５とする。 Specifically, the calculation unit 23 is a standardized expression of the failure point, with the processor reading out the entire line impedance Kz from the storage unit 21 and the Kz, each current value and voltage value acquired from the acquisition unit 22. The ratio d is calculated based on the formula (1).
(Equation 1)

I1: Own end current, I2: Counter end current V1: Own end voltage, V2: Counter end voltage IL1: Self end reactor current, IL2: Counter end reactor current Kz: Total line impedance Kρ: Leakage current concentration approximate equivalent point In the embodiment, the leakage current concentration approximate equivalent point Kρ is a half value of the total line impedance, for example, 0.5.

  Further, the failure point locating apparatus includes a communication unit or a display unit (not shown), and the communication unit may transmit the calculated ratio d (failure point) to the outside, or the display unit calculates the ratio d ( The failure point) may be displayed so that the user can read it. The communication means may be wired or wireless. The display means includes, for example, a liquid crystal display, but is not limited thereto, and known ones can be used.

[1-2. Action]
First, the leakage point concentration approximate equivalent point Kρ will be described, and then the fault point orientation formula shown in the above equation (1) will be described.

  In the transmission line 1, a leakage current flows from the transmission line 1 to the ground due to the parasitic capacitance. As shown in FIG. 3, this leakage current normally flows evenly from the power transmission line 1, but here it is approximated as flowing from one point. This point is referred to as a leak point concentration approximate equivalent point Kρ (hereinafter also simply referred to as “equivalent point”). Kρ is a ratio with respect to the total line impedance Kz of the power transmission line 1, and when the total line impedance Kz is 1PU, Kρ is a value from 0 to 1. As described above, in this embodiment, Kρ = 0.5.

  The failure point is obtained by calculating a ratio d between the total line impedance Kz of the transmission line 1 and the line impedance KzL up to the failure point. Here, the line impedance KzL up to the failure point is a value that cannot be measured, and is obtained from the voltage, current, and branch reactor current of each end 1a, 1b that can be measured. The concept will be described below with reference to FIG.

Ｖρは、式（３）に示すように、自端電流Ｉ１から自端リアクトル電流ＩＬ１を引いた電流に、等価点Ｋρまでの線路インピーダンスＫρ×Ｋｚを乗じたものである。ＶＬ１は、式（４）に示すように、自端電流Ｉ１と相手端リアクトル電流ＩＬ２の和に、故障点までの線路インピーダンスＫｚと等価点Ｋρまでの線路インピーダンスＫρ×Ｋｚの差分を乗じた値となる。ＶＬ２は、式（５）に示すように、相手端電流Ｉ２と相手端リアクトル電流ＩＬ２の差分に、全線路インピーダンスＫｚと故障点までの線路インピーダンスＫｚＬの差分を乗じた値となる。
（数３）

（数４）

（数５）

なお、両端の分岐リアクトル２ａ、２ｂに流れ込む分岐リアクトル電流が漏れ電流Ｉρを相殺するものとしている（Ｉρ＝−（ＩＬ１＋ＩＬ２））。 First, as shown in the equation (2), the self-end voltage V1 is represented by the sum of the line drop voltage Vρ up to the equivalent point Kρ, the line drop voltage VL1 from the equivalent point Kρ to the fault point, and the fault point voltage Vf. The counterpart terminal voltage V2 can be expressed by the sum of the line drop voltage VL2 up to the failure point and the failure point voltage Vf.
(Equation 2)

Vρ is obtained by multiplying the current obtained by subtracting the self-end reactor current IL1 from the self-end current I1 by the line impedance Kρ × Kz up to the equivalent point Kρ, as shown in Expression (3). VL1 is a value obtained by multiplying the sum of the self-end current I1 and the counterpart end reactor current IL2 by the difference between the line impedance Kz up to the failure point and the line impedance Kρ × Kz up to the equivalent point Kρ, as shown in Equation (4). It becomes. As shown in Expression (5), VL2 is a value obtained by multiplying the difference between the counterpart end current I2 and the counterpart end reactor current IL2 by the difference between the total line impedance Kz and the line impedance KzL up to the failure point.
(Equation 3)

(Equation 4)

(Equation 5)

Note that the branch reactor current flowing into the branch reactors 2a and 2b at both ends cancels the leakage current Iρ (Iρ = − (IL1 + IL2)).

式（６）について、Ｖ１からＶ２を引き、未知な故障点電圧Ｖｆを相殺し、ＫｚＬについて解くことで、式（７）が得られる。
（数７）

このようにして、測定可能な電流、電圧の値から未知である故障点までの線路インピーダンスＫｚＬを得ることができる。最後に、式（７）をＫｚで割ると、式（１）の故障点の標定式を得ることができる。 By substituting Equations (3) to (5) into Equation (2), the simultaneous equations of Equation (6) can be established.
(Equation 6)

With respect to Expression (6), Expression (7) is obtained by subtracting V2 from V1, canceling out the unknown failure point voltage Vf, and solving for KzL.
(Equation 7)

In this way, the line impedance KzL from the measurable current and voltage values to the unknown fault point can be obtained. Finally, when equation (7) is divided by Kz, the failure point orientation equation of equation (1) can be obtained.

  Here, according to the equation (1), d is obtained from the value of Kρ. In this embodiment, Kρ = 0.5. That is, it is approximated that the equivalent point is the center of the own end 1a and the counterpart end 1b. Thereby, a failure point can be obtained approximately. The reason is that the failure point standardization formula is expressed by the above formula (1) regardless of whether a failure occurs on the other end 1b side after the equivalent point or a failure occurs on the own end 1a side from the equivalent point. This is because no matter where the equivalent point is approximated, the error point can be reduced and the failure point can be determined. That is, the equivalent point can be arbitrarily determined within the branch reactor installation section. Therefore, when the equivalent point is defined in the branch reactor installation section, it may be assumed that it is different from the equivalent point that can be approximated in practice. For example, although Kρ = 0.9 is defined, if the actual equivalent point is Kρ = 0.1, the fault point is affected by the deviation. In the present embodiment, by defining Kρ = 0.5, the deviation from the actual equivalent point can be minimized, so that the failure point can be easily determined.

  Next, even when a failure occurs on the other end 1b side after the equivalent point, or when a failure occurs on the own end 1a side relative to the equivalent point, the failure point orientation formula is the same in the form of the above equation (1). That will be explained.

  The fault point orientation formula has a different calculation process depending on the positional relationship between the fault point d and the equivalent point Kρ. That is, the case can be divided into cases where Kρ ≦ d and Kρ> d.

(1) When Kρ ≦ d (when a failure occurs on the other end 1b side after the equivalent point)
In this case, since it is the same as the calculation process of FIG. 1 and Formula (2)-Formula (7), it abbreviate | omits.

式（８）をＫｚＬについて解くと、式（９）のように表すことができる。
（数９）

式（９）をＫｚで割ると、式（１０）を得ることができる。
（数１０）

この式（１０）は、式（１）と同じであることが分かる。すなわち、等価点が分岐リアクトル設置区間のどこにあっても、故障点は、式（１）で標定できることが分かる。 (2) When Kρ> d (when a failure occurs on the end 1a side from the equivalent point)
As shown in FIG. 4, as in the case of (1), when the difference voltage between both ends 1a and 1b is calculated in consideration of the flow of the branch reactor current to the equivalent point, it can be expressed by equation (8). .
(Equation 8)

When Equation (8) is solved for KzL, it can be expressed as Equation (9).
(Equation 9)

When equation (9) is divided by Kz, equation (10) can be obtained.
(Equation 10)

It can be seen that the equation (10) is the same as the equation (1). That is, it can be seen that the failure point can be determined by the equation (1) wherever the equivalent point is in the branch reactor installation section.

[1-3. effect]
The failure point locating device of the present embodiment is a failure point locating device that locates the failure point in the installation section of the branch reactors 2a, 2b of the transmission line 1 embedded in the ground while the branch reactors 2a, 2b are installed. Thus, the storage unit 21 in which the total line impedance Kz of the power transmission line 1 is stored in advance, the local terminal voltage V1, the partner terminal voltage V2, the terminal terminal current I1, the partner terminal current I2, the terminal terminal reactor current IL1, and the partner terminal reactor An acquisition unit 22 that acquires the current IL2, and a calculation unit 23 that calculates a ratio d of the total line impedance Kz of the power transmission line 1 and the line impedance KzL up to the failure point. The calculation unit 23 is acquired by the acquisition unit 22. Self-terminal voltage V1, mating terminal voltage V2, self-terminal current I1, mating terminal current I2, self-terminal reactor current IL1, mating terminal reactor current IL2, and all line impedance Based on the dance Kz, and calculate the ratio d.

  Thereby, a failure point can be located in the shunt reactor installation section of the transmission line buried in the ground.

  In particular, the calculation unit 23 calculates the ratio d based on the above formula (1) and sets Kρ = 0.5. As a result, the failure point can be easily determined with a small error.

[2. Second Embodiment]
[2-1. Constitution]
A second embodiment will be described with reference to FIG. The basic configuration of the second embodiment is the same as that of the first embodiment. Only the differences from the first embodiment will be described, and the same parts as those in the first embodiment will be denoted by the same reference numerals and detailed description thereof will be omitted.

  FIG. 5 is a functional block diagram of the failure point locating device according to the second embodiment. The failure point locating device according to the second embodiment includes a storage unit 24 that stores the current values I1, I2, IL1, and IL2, and the voltage values V1 and V2 acquired by the acquisition unit 22.

  That is, the acquisition unit 22 acquires different current values I1, I2, IL1, and IL2 and voltage values V1 and V2 at different times. For example, when the acquisition unit 22 acquires the current values I1, I2, IL1, IL2, and the voltage values V1, V2 at time t1 and time t2 (<t1), the storage unit 24 stores each value at time t1. The storage unit 24 can be configured by a recording medium such as a memory or a hard disk, and outputs the stored data to the calculation unit 23 in response to a request from the calculation unit 23.

  The calculation unit 23 calculates the ratio d based on the voltages V1 and V2, currents I1, I2, IL1, and IL2 acquired at different times t1 and t2, and the total line impedance Kz. Specifically, in the processor 23, the processor reads the entire line impedance Kz from the storage unit 21, and reads the current values I1, I2, IL1, IL2, and the voltage values V1, V2 at the time t1 from the storage unit 24. The current values I1, I2, IL1, and IL2, and the voltage values V1 and V2 at the time t2 are read from the acquisition unit 22, and the ratio d is calculated by solving the simultaneous equations of the above formula (1) at the times t1 and t2. Note that the voltages V1 and V2 and the currents I1, I2, IL1, and IL2 acquired at different times t1 and t2 have different values.

[2-2. Action / Effect]
The operation of this embodiment will be described. As shown in equation (1), voltages V1 and V2, currents I1, I2, IL1, and IL2 are existing values that can be measured, whereas Kρ and d are unknowns. In the first embodiment, the failure point is simply determined by setting Kρ to 0.5, but Kρ and d are essentially unknowns.

  Therefore, in this embodiment, current values I1, I2, IL1, and IL2 and voltage values V1 and V2 acquired at different times t1 and t2 are used. That is, since the current values I1, I2, IL1, and IL2, and the voltage values V1 and V2 acquired at different times t1 and t2, are different values, the current values I1, I2, IL1, and IL2, and the voltage value V1, at each time. By substituting V2 into equation (1), two simultaneous equations with Kρ and d as unknowns can be obtained. And the calculating part 23 can obtain this ratio d and K (rho) by solving this simultaneous equation.

  In this way, since the ratios d and Kρ can be obtained from the measured values, the fault point can be accurately determined.

[3. Other Embodiments]
In the present specification, a plurality of embodiments according to the present invention have been described. However, these embodiments are presented as examples and are not intended to limit the scope of the invention. The above embodiments can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the invention described in the claims and equivalents thereof as well as included in the scope and gist of the invention.

  For example, the storage unit 24 stores the current values I1, I2, IL1, and IL2 and the voltage values V1 and V2 at different times, and the failure point locating device determines whether or not each electric quantity stored by the storage unit 24 is different. A determination unit for determining Thereby, it is possible to determine the amount of electricity that can be used in the calculation unit 23. For example, if the current values I1, I2, IL1, and IL2, and the voltage values V1 and V2 acquired at different times t1 and t2 are the same, the simultaneous equation cannot be solved by the calculation unit 23. If the current value and the voltage value are different, the simultaneous equations can be solved.

DESCRIPTION OF SYMBOLS 1 Transmission line 1a Own end 1b Opposite end 2a Branching reactor 2b Branching reactor 21 Storage part 22 Acquisition part 23 Calculation part 24 Storage part

Claims (9)

A failure point locating method for locating a failure point in an installation section of the branch reactor of a transmission line embedded in the ground while a branch reactor is installed,
An acquisition step of acquiring a self-terminal voltage, a partner terminal voltage, a self-terminal current, a partner terminal current, a self-terminal reactor current, and a partner terminal reactor current;
A calculation step for calculating the ratio of the total line impedance of the power transmission line and the line impedance up to the failure point,
With
The calculation step calculates the ratio based on the own end voltage, the other end voltage, the own end current, the other end current, the other end reactor current, the other end reactor current, and the all line impedance obtained by the obtaining step. To do,
A fault location method characterized by The calculation step calculates the ratio based on the following formula (1):
The fault location method according to claim 1, wherein:

I1: Own end current, I2: Counter end current V1: Own end voltage, V2: Counter end voltage IL1: Self end reactor current, IL2: Counter end reactor current Kz: Total line impedance Kρ: Leakage current concentration approximate equivalent point In the calculation step, the leakage current concentration approximate equivalent point is set to a half value of the total line impedance,
The failure point locating method according to claim 2. In the acquisition step, each voltage and current is acquired at different times,
In the calculation step, calculating the ratio based on each voltage, current acquired at the different time, and the total line impedance,
The failure point locating method according to claim 1 or 2. A failure point locating device for locating a failure point in an installation section of the branch reactor of a transmission line embedded in the ground while a branch reactor is installed,
A storage unit in which all line impedances of the transmission lines are stored in advance;
An acquisition unit for acquiring a self-end voltage, a counterpart voltage, a self-end current, a counterpart end current, a self-end reactor current, and a counterpart end reactor current;
An arithmetic unit that calculates the ratio of the total line impedance of the transmission line and the line impedance up to the failure point,
With
The calculation unit calculates the ratio based on the own end voltage, the other end voltage, the own end current, the other end current, the other end reactor current, the other end reactor current, and the all line impedance acquired by the acquisition unit. To do,
Failure point locator characterized by The calculation unit calculates the ratio based on the following equation (2):
The failure point locating device according to claim 5.

I1: Own end current, I2: Counter end current V1: Own end voltage, V2: Counter end voltage IL1: Self end reactor current, IL2: Counter end reactor current Kz: Total line impedance Kρ: Leakage current concentration approximate equivalent point The arithmetic unit, the leakage current concentration approximate equivalent point to be a half value of the total line impedance,
The failure point locating device according to claim 6. The acquisition unit acquires each voltage and current at different times,
The calculation unit calculates the ratio based on each voltage, current acquired at the different time, and the total line impedance,
The failure point locating device according to claim 5 or 6. A fault location program that locates a fault point in an installation section of the branch reactor of a transmission line embedded in the ground while a branch reactor is installed,
On the computer,
An acquisition process for acquiring a self-terminal voltage, a partner terminal voltage, a self-terminal current, a partner terminal current, a self-terminal reactor current, and a partner terminal reactor current;
Arithmetic processing to calculate the ratio of the total line impedance of the transmission line and the line impedance up to the failure point,
And execute
The calculation process calculates the ratio based on the self-end voltage, the counterpart end voltage, the self-end current, the counterpart end current, the self-end reactor current, the counterpart end reactor current, and the total line impedance acquired by the acquisition process. To do,
Fault location program characterized by

Images