JP6552949B2 - Failure location device, method and program thereof - Google Patents

Description

  Embodiments of the present invention relate to an apparatus for locating a fault in a transmission line, and a method and program thereof.

  In recent years, a stable power transmission system is required from the 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 a method of locating a failure point in a power transmission line, a method of performing positioning based on a line reactance value obtained from a voltage and a current of one end of the power transmission line and its direction is known. FIG. 12 is a principle diagram for explaining the conventional method. As shown in FIG. 12, an AC power supply 101 is connected to one end of the power transmission line 102. AC power is transmitted from the AC power supply 101 to the other end of the power transmission line 102.

The failure point localization formula of the conventional method is obtained as follows. That is, when a failure occurs in the transmission line 102, a case where the current supplied from the AC power supply 101 passes through the reference end of the transmission line 102 and flows out to the failure point through the orientation point. Although the fault point constant Z _f is indeterminate, since the control point and the fault point are connected at a pinpoint, it can be regarded as resistance between the control point and the fault point. That is, since it is considered that there is no coil component, the fault point voltage V _f and the reference end current I ₁ can be regarded as the same phase.

Also, the reference end voltages V ₁ can be regarded as plus line drop voltage from the reference edge to the failure point fault point voltage V _f. Further, the line constant Z ₁ from the reference edge to the fault point is the sum of the resistance component and reactance component of the reference edge to the fault point. From the above, the relationship between the current and the voltage in FIG. 12 is shown in FIG. 13 as a vector diagram.

From FIG. 13, the reactance component determined from the reference end voltage V ₁ and the reference end current I ₁ is equivalent to the line reactance from the reference end to the failure point. This is because there is a right triangle relationship between the line constant (impedance), resistance, and reactance, with the line constant as the hypotenuse, resistance as the adjacent side, and reactance as the opposite side.

Therefore, when the phase difference between the reference end voltages _{V 1} and fault point voltage _{V f} and phi _{the If,} line reactance jX can be obtained by the following equation (101).
(Number 101)

Japanese Patent Laid-Open No. 2008-261751

  By the way, with the complication of the operation form of the transmission line, a leakage current is generated in the transmission line, and this leakage current may flow into the failure point. However, conventional power line fault location methods do not take into account the leakage current that flows into the fault point. Therefore, in the power transmission line where leakage current may occur, the positioning value obtained using the conventional positioning method includes a large positioning error, and there is a problem that accurate fault point can not be located.

  The failure point locating device, the method and the program according to the embodiment of the present invention are made to solve the above-described problems, and accurate failure point locating is possible even if a leakage current occurs in the transmission line. It is an object of the present invention to provide a fault localization apparatus, method and program thereof.

  In order to achieve the above object, the failure point locating device of the present embodiment is a failure point locating device for locating a failure point of a transmission line, and includes a current and voltage at a reference end of the transmission line, and the failure point. , A total current calculation unit for calculating a total current obtained by adding the current at the reference end and the leakage current, a current at the reference end, and the total current A current phase difference calculating unit that calculates the phase difference of the voltage phase, a voltage phase difference calculating unit that calculates the phase difference between the voltage at the reference end and the total current, a storage unit in which the line angle of the power transmission line is stored in advance And a reactance calculation unit configured to calculate a line reactance from the reference end to the failure point based on the current and voltage at the reference end, the phase difference between the two, and the line angle.

  The present embodiment can also be understood as a method for realizing the functions of the respective units by a computer or an electronic circuit, and a program for causing a computer to execute the processes of the respective units.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the alternating current transmission system to which the failure point localization apparatus which concerns on 1st Embodiment is applied. It is a functional block diagram showing composition of a fault localization device concerning a 1st embodiment. FIG. 6 is a vector diagram of current and voltage in reactance localization of the system of FIG. 1 in the presence of leakage current. It is a graph which shows the orientation reactance with respect to the phase difference of the reference end electric current (1PU) of Example 1, and a leakage current (0.5PU). It is a graph which shows the standard reactance with respect to the phase difference of the reference end electric current (1PU) of Example 2, and a leakage current (1PU). It is a graph which shows the orientation reactance with respect to the phase difference of the reference end electric current (1PU) of Example 3, and leakage current (2PU). It is a figure which shows the alternating current transmission system to which the failure point localization apparatus which concerns on 2nd Embodiment is applied. It is a functional block diagram of the fault localization device concerning a 2nd embodiment. FIG. 8 is a vector diagram of current and voltage in reactance positioning of the system of FIG. 7 in the presence of leakage current. It is a figure which shows the alternating current transmission system to which the failure point localization apparatus which concerns on 3rd Embodiment is applied. It is a functional block diagram of the failure point localization apparatus of 3rd Embodiment. It is an orientation principle figure for demonstrating a conventional system. It is a vector diagram of current and voltage showing the relationship of FIG.

[1. First embodiment]
[1-1. overall structure]
Hereinafter, the failure point locating device according to the present embodiment will be described with reference to FIGS. FIG. 1 is a diagram showing an AC power transmission system to which a failure localization apparatus according to the present embodiment is applied.

  As shown in FIG. 1, the AC power transmission system includes an AC power supply 1 and a power transmission line 2, the AC power supply 1 is connected to the reference end of the power transmission line 2, and the AC power supply or load is connected to the other end of the power transmission line 2. Has been. The AC power supply 1 supplies power to the load at the other end and the like via the power transmission line 2. The AC power source 1 is, for example, an AC system or substation of an electric power company. The power transmission line 2 is a line for sending AC power, and includes overhead lines and cables. Examples of the AC power transmission system include a system that supplies power to a train such as a bullet train.

  The failure point locating device uses the power transmission line 2 as a target for location, and locates the failure point of the power transmission line 2. The failure point is a point at which a short circuit or ground fault has occurred. The fault localization apparatus determines a line reactance from the reference end of the transmission line 2 to the fault point in consideration of the leakage current flowing through the transmission line 2 when an accident occurs.

A current I ₁ passing through the reference end and a leakage current I _ρ caused by an accident flow into the failure point through the orientation point that is the orientation point of the line reactance 2. The reference end is a point on the transmission line 2 used as a reference when locating the failure point, and is a point on the transmission line 2 on the side of the AC power supply 1 from the control point. For example, when a train is connected to the side of the power transmission line 2 opposite to the connection end of the AC power supply 1, the leakage current _Iρ occurs when the train functions as a battery when an accident occurs.

[1-2. Detailed configuration]
(Trouble point locating device)
FIG. 2 is a functional block diagram showing the configuration of the fault localization apparatus according to the present embodiment. As shown in FIG. 2, the failure point locating device includes an electric quantity measurement unit 31, a total current calculation unit 32, a current phase difference calculation unit 33, a voltage phase difference calculation unit 34, a storage unit 35, and a reactance calculation unit 36. doing. Each of the units 32 to 34, 36 includes a single computer or a plurality of networked computers. That is, the failure point localization apparatus stores a program in an HDD, an SSD, or the like, appropriately expands it in a RAM, and performs various operations by processing with a CPU.

The electrical quantity measuring unit 31 measures the current I ₁ and the voltage V ₁ at the reference end of the transmission line 2. When an accident occurs, the leakage current I _ρ flows through the transmission line 2 and may flow into the failure point. The electric quantity measurement unit 31 also measures the leakage current I _{流 れ る} flowing to the failure point. The electric quantity measuring unit 31, for example, the current I ₁ of the reference edge is determined by the current detector provided in the reference end, the leakage current I _[rho, measured by the current detector provided at a location other than the reference edge . Voltages V ₁ is measured by the voltage detector for detecting a voltage between the example AC power supply 1 and the reference end.

The total current calculation unit 32 calculates the total current I by adding the current I ₁ at the reference end obtained by the electric quantity measurement unit 31 and the leakage current I _ρ . This total current I is the fault point current _If flowing to the fault point. That is, the relational expression I = I _f = I ₁ + I _成立 holds.

Current phase difference calculation unit 33 calculates a phase difference phi _f between the current I ₁ of the reference edge and the sum current I. Voltage phase difference calculator 34 calculates a phase difference phi _{the If} the voltage V ₁ of the reference edge and the sum current I. The phase difference φ _f is calculated from the active power and reactive power of the reference end voltage V ₁ and the total current I, and the phase difference φ _If is calculated from the active power and reactive power of the reference end current I ₁ and the total current I. Be done.

The storage unit 35 stores in advance various parameters necessary for calculation for determining a failure point and a program used for the calculation. The parameters include the line constant Z in each section of the power transmission line 2 and the line angle of the line constant. Line angle is a trigonometric ratio function angle resistor R component and the reactance component jX of the transmission line 2, as shown in Figure 3 will be described later, formed by the line constant Z ₁ and the resistance R component from the reference edge to the fault point It is an angle. These parameters are one of the electrical characteristics of the transmission line 2 and are values uniquely determined by the configuration of the material of the transmission line 2 and the like. As a program memorize | stored in this memory | storage part 35, the program used for the calculation of each calculation part 32-34, 36 is mentioned.

The reactance calculation unit 36 calculates the line reactance jX from the reference end to the failure point in consideration of the leakage current I _ρ . The formula for calculating the line reactance jX, that is, the fault location standard formula is (Formula 1) below.
(Equation 1)

  Further, the failure point locating device includes a communication unit or a display unit (not shown), and the communication unit may transmit the calculated line reactance to the outside, or the display unit may display the calculated line reactance, May be readable. The communication means may be wired or wireless. Moreover, although a liquid crystal display etc. are mentioned as a display means, for example, it can not limit to this and can use a well-known thing.

[1-3. Action]
First, the fault point location formula shown in the above (Formula 1) will be described in comparison with the conventional location formula, then the operation of the fault location apparatus of the present embodiment will be described, and further examples will be shown.

[1-3-1. Failure point localization formula]
FIG. 3 is a vector diagram of current and voltage in reactance positioning of the system of FIG. 1 in the presence of leakage current. As shown in FIG. 3, the line reactance to be determined can be determined by determining the opposite side of a right triangle with I ₁ Z ₁ as the oblique side and I ₁ R as the adjacent side. That is, the line constant _{Z 1,} since expressed by the sum of the resistance R component and the reactance X component _(Z 1 = R + jX), the opposite sides _I 1 jX may be divided by _{I 1.} Here, the angle formed by I ₁ Z ₁ and I ₁ R is the line angle k _θ , and the angle formed by the fault point current _If and the voltage V ₁ is the phase difference φ _If .

As shown in FIG. 3, in a right triangle having an oblique side as I ₁ Z ₁ , assuming that the opposite side facing the phase difference φ _If is S, the following three relational expressions (1) to (3) hold, By deleting I ₁ Z ₁ , the orientation formula of the above (Formula 1) can be obtained.
S / V ₁ = sinφ _If (1)
S / I ₁ Z ₁ = sin (k _θ −φ _f ) (2)
jI ₁ X / I ₁ Z ₁ = sink _θ (3)

As shown in FIG. 1 and FIG. 3, when a failure point occurs in the transmission line 2 due to a short circuit or a ground fault, a leakage current I _に is generated in the transmission line 2 and a current I ₁ at the reference end is generated at the failure point. And leakage current I _ρ flow in. Since the reference end current I ₁ and the leakage current I _{有 す る} each have a phase, a phase difference may occur between the two currents. Therefore, the fault point current I _f flowing to the fault point is deviated from the reference end current I _{1 by} the phase difference φ _{f of the} current I ₁ and the leakage current I _ρ .

As shown in the above (Equation 101), the conventional formula for determining the failure point does not take into consideration the phase shift due to the leakage current I _ρ . Therefore, as shown in FIG. 13, line reactance calculated by (Formula 101) is determined like line orientation reactance error _{Xe (= V1 · sinφ I1 -I} 1 jX) minute shifts.

On the other hand, in this embodiment, as is clear from (Equation 1), the phase difference φ _f between the reference end current I ₁ and the leakage current I _ρ is included, and the leakage current I _ρ is taken into consideration. . Further, due to the presence of the leakage current I _ρ , the phase of the failure point current I _f (total current I) also changes from the reference end current I ₁ . Therefore, the phase difference φ _If also takes into consideration the leakage current I _ρ . As described above, according to the present embodiment, since the change in phase due to the leakage current I _考慮 is considered, it is possible to obtain an accurate line reactance.

[1-3-2. Operation]
The operation of the fault localization apparatus of the present embodiment will be described in detail. In addition, the operation | movement shown here is an example, Comprising: You may make order of the below-mentioned steps S02-S04 back and forth or parallel.

First, in step S01, the electric quantity measurement unit 31 measures the current I ₁ and the voltage V ₁ at the reference end and the leakage current I _ρ . Next, in step S02, the total sum current calculation unit 32, measured by adding the current I ₁ and the leakage current I _[rho electric quantity measuring unit 31 calculates the sum current I. This total current I is equal to the fault point current _If . Step S03 is the current phase difference calculator 33 calculates a phase difference phi _f between the current I ₁ of the reference edge and the sum current I. In step S 04, the voltage phase difference calculation unit 34 calculates the phase difference φ _If between the reference end voltage V ₁ and the total current I.

The fault point current _If and the fault point voltage _Vf have the same phase. Since the control point and the failure point are connected at the pin point, the failure point constant Z _f can be regarded as a resistance component, and there is no phase shift due to the coil component. Accordingly, the phase difference φ _If is equal to the phase difference between the reference end voltage V ₁ and the failure point voltage V _f .

Further, as step S05, the reactance calculation unit 36 determines the reference based on the current I ₁ , voltage V ₁ , phase difference φ _f , φ _If , line angle k _θ , and (Equation 1) obtained from the units 31 to 35. Calculate the line reactance from the end to the failure point. The calculated line reactance value may be transmitted to the outside by the communication means, or the value may be displayed by the display means.

[1-3-3. Example]
In the present embodiment, Examples 1 to 3 based on the above (Formula 1) are shown. As shown in FIG. 1, in the power transmission line 2 in which a leakage current exists, the phase angle of the leakage current was rotated from 0 to 360 °, and the line reactance from the reference end to the failure point was calculated.

  The conditions of the first to third embodiments are as follows, and the line reactance jX from the reference end to the failure point is set to 1 [PU]. In other words, if the calculated line reactance indicates 1 [PU], it can be determined that an accurate fault location has been achieved, and if any other value is indicated, it can be determined that an orientation error is included.

The point that the phase difference between the reference end voltage V ₁ , line angle k _θ , and leakage current I _ρ is rotated by 0 to 360 ° is common, and the value of the leakage current I _ρ is different from 0.5, 1 and 2, respectively. did.
Examples 1-3: I ₁ = 1 [PU], V ₁ = ((1.26) ² + (1.38) ² ) ^1/2 [PU], k _θ = 60 [DEG]
Example 1: I _ρ = 0.5 [PU]
Example 2: I _ρ = 1 [PU]
Example 3: I _ρ = 2 [PU]

The results are shown in FIGS. That is, FIG. 4 shows the result of Example 1, FIG. 5 shows the result of Example 2, FIG. 6 shows the result of Example 3, and the horizontal axis of the graph shown in each figure shows the leakage current I に 対 す_る to the reference end current I ₁ of it shows the phase difference phi _[rho, indicating the line reactance jX the vertical axis is the orientation. Further, Conventional Examples 1 to 3 are shown in FIGS. 4 to 6 for comparison of Examples 1 to 3. FIG. Conventional Examples 1 to 3 are results based on the conventional (Formula 101) under the same conditions as in Examples 1 to 3.

As shown in FIGS. 4 to 6, for example, when there is no phase difference between the reference end current I ₁ and the leakage current I _ρ (φ _f = 0), the line reactances of the respective examples and the conventional example match. However, in the conventional examples 1 to 3, when the directions of the reference end current I ₁ and the leakage current I _ρ do not coincide with each other, it can be seen that the value of the standardized line reactance fluctuates and a standardization error is included. On the other hand, in Examples 1 to 3, even if there is a phase difference between the reference end current I ₁ and the leakage current I _ρ , a constant line reactance value (1PU) is obtained, and the failure is accurately caused. It can be seen that the points can be located.

In the conventional examples 1 to 3, the orientation error increases as the ratio of the value of the leakage current I _ρ to the reference end current I ₁ increases. In the first to third examples, a constant line reactance value is obtained. It can be understood that accurate fault point localization can be performed even if the magnitude and phase of the leakage current I _{変 化} change.

[1-4. effect]
The fault localization apparatus according to the present embodiment is a fault localization apparatus for locating the fault point of the transmission line 2 and includes the current I ₁ and the voltage V ₁ at the reference end of the transmission line 2 and the leakage current I flowing to the fault point. an electrical quantity measuring unit 31 that measures _ρ , a total current calculating unit 32 that calculates a total current I obtained by adding the current I ₁ at the reference end and the leakage current I _ρ, and the current I ₁ and the total at the reference end Current phase difference calculation unit 33 for calculating phase difference φ _f with current I, voltage phase difference calculation unit 34 for calculating phase difference φ _If between reference voltage V ₁ and total current I, and power transmission line 2 From the reference end to the failure point based on the storage unit 35 in which the line angle k _θ is stored in advance, the current I ₁ and the voltage V ₁ at the reference end, the phase differences φ _f and φ _If , and the line angle k _θ. A reactance calculation unit 36 for calculating the line reactance jX of And obtain way.

As a result, even when the leakage current I _に occurs in the transmission line 2 to be localized, the phase shift caused by the presence of the leakage current I _加 is also taken into consideration, so that the failure point can be accurately determined. it can.

[2. Second embodiment]
[2-1. Constitution]
A second embodiment will be described using FIGS. 7 to 9. The second embodiment has the same basic configuration as 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. 7 is a diagram showing an AC power transmission system to which the fault localization device according to the second embodiment is applied. The power transmission line 2 of the second embodiment has a basic line 21 having a reference end and a branch point 2a, and a branch path 22 branched from the basic line 21 at the branch point 2a. The reference end is located between the AC power source 1 and the branch point 2a. The reference end and the branch point 2 a are stationary in the power transmission line 2.

  Here, with reference to the branch point 2a, the AC power supply 1 side is referred to as the front, and the opposite side of the AC power supply 1 as the rear. That is, the reference end side is the front as viewed from the branch point 2a, and a point other than the front is the rear. The rear includes a power transmission line downstream of the branch point 2 a of the basic line 21 and a branch path 22. Although the failure point occurs in any place in the transmission line 2, the position where the occurrence is assumed is forward or backward.

Because the reference edge distance between the branch point 2a is fixed, determined in advance even during line constant Z _1-1. The storage unit 35, line constant Z _1-1 between the reference end and the branching point 2a are stored in advance. In addition, in the storage unit 35, various threshold values necessary for the determination described later are stored in advance.

FIG. 8 is a functional block diagram of the fault localization device according to the second embodiment. The reactance calculation unit 36 includes a front fault orientation calculation unit 36a and a rear fault orientation calculation unit 36b. The forward failure localization calculation unit 36a calculates the line reactance jX from the reference end to the failure point based on the forward failure localization formula that locates a failure point that has occurred on the front side which is the reference end side from the branch point 2a. The forward failure location formula is the above (Formula 1). That is, when a failure point occurs in the front, the reference end current I ₁ and the leakage current I _{流 れ} flowing from the rear flow into the failure point, so the front failure is determined by the above (Equation 1).

The rear failure localization calculation unit 36b calculates a line reactance from the reference end to the failure point when a failure point occurs behind the branch point 2a. In this calculation, as in the first embodiment, the reference end current I ₁ and voltage V ₁ measured by the electric quantity measurement unit 31, the phase difference φ _f calculated by the current phase difference calculation unit 33, and the voltage phase difference calculation other phase difference phi _{the If} calculated in section 34, using the backward fault point locating formula shown in the storage unit 35 stored in the line constants Z _1-1 and the following (equation 2).
(Equation 2)

In FIG. 7, the line drop voltage from the reference end to the branch point 2a is I ₁ · Z _1-1 . Further, a line drop voltage to fault point from the branch point _{2a (I 1 + I ρ)} · Z 1-2. Since the line constant Z _f point of failure is indeterminate, the fault point voltage V _f is also indefinite. However, the fault point current I _f and V _f, which flows into the fault point are in phase. The relationship shown in FIG. 7 is shown in FIG. 9 as a current vector diagram.

As shown in FIG. 9, the reference terminal voltages V ₁ is the fault point voltage Vf, is obtained by adding the line drop voltage to fault point from the branch point 2a, the line voltage drop from the reference edge to the branch point 2a The above (Equation 2) can be obtained from FIG.

  Although FIG. 7 shows an example in which the failure point occurs in the basic line 21 of the rear, the failure point may occur in the branch path 22. Even in this case, the rear failure point can be located using the above (Equation 2).

  Furthermore, the failure point locating device includes a determination unit 37 that determines whether a failure point has occurred in the front or in the rear. That is, determination unit 37 receives the input of the line reactance calculated by forward failure localization calculation unit 36a, and determines whether the input value is within the predetermined threshold stored in storage unit 35 or not. When the input value is within the predetermined threshold, the determination unit 37 determines that a failure point has occurred in the front, and when the input value exceeds the predetermined threshold, determines that a failure point has occurred in the rear. . In this case, a command to calculate the line reactance is output to the rear failure localization calculation unit 36b. In addition, since the distance from the reference end to the branch point 2a is known, the known distance of the inductance determined from the relational expression between the distance and the line constant (inductance) is taken as the line constant, for example. Can do.

[2-2. Operation]
The operation of the fault localization device of this embodiment will be described. The same points as the first embodiment will not be described.

When the fault location device calculates the current I ₁ , voltage V ₁ , phase difference φ _f , φ _If at the reference end, based on these values, the line angle k _θ and the above (formula 1), the forward fault location is determined. I do. That is, the forward failure localization calculation unit 36a calculates the line reactance from the reference end to the failure point, and outputs the calculated value to the determination unit 37.

  The determination unit 37 determines whether the line reactance value input from the forward failure localization calculation unit 36a is within a predetermined threshold stored in the storage unit 35. If the line reactance value is within the predetermined threshold value, the determination unit 37 determines that the failure point has occurred in the front, and the failure point localization in the rear is not performed.

On the other hand, when the line reactance value input from the forward failure orientation calculation unit 36a exceeds a predetermined threshold stored in the storage unit 35, it is determined that a failure point has occurred at the rear. In this case, the determination unit 37 outputs a calculation command to the rear failure orientation calculation unit 36b, and the rear failure orientation calculation unit 36b includes a current I ₁ , a voltage V ₁ , a phase difference φ _f , φ _If , a line angle k _θ , The line reactance jX from the reference end to the failure point is calculated based on the line constant Z _1-1 and the rear failure location equation of the above (formula 2).

  As described above, although the operation of the fault localization apparatus according to the second embodiment has been described, the above operation is an example, and the line reactance is paralleled by the forward failure localization calculation unit 36a and the rear failure localization calculation unit 36b. May be calculated, and the determination unit 37 may determine whether the occurrence of the failure point is forward or backward.

[2-3. effect]
(1) In the fault location apparatus of the present embodiment, the power transmission line 2 includes a basic line 21 having a reference end and a branch point 2a, and a branch path 22 that branches from the basic line 21 at the branch point 2a. The reactance calculation unit 36 has a forward failure localization calculation unit 36a that calculates the line reactance jX based on a forward failure localization formula that locates a failure point generated forward on the reference end side as viewed from the branch point 2a. If the value calculated by the failure localization calculation unit 36a is within the predetermined threshold, it is determined that a failure point has occurred in the front, and the value calculated by the forward failure localization calculation unit 36a is greater than the predetermined threshold Has a determination unit 37 that determines that a failure point has occurred at the rear other than the front. Thereby, a fault section can be specified bordering on branch point 2a.

(2) in the storage unit 35 is stored line constant _{Z 1-1} between the reference end and the branching point 2a in advance, the reactance calculator 36, line constant _{Z 1-1} and the current _{I 1,} the voltage V ₁ , a rear fault localization calculation unit 36a for calculating a line reactance based on a rear fault localization formula that locates a fault point generated at the rear with a phase difference φ _f , φ _If , a track angle k _θ , The unit 36a calculates the line reactance jX based on the backward failure orientation formula when the determination unit 37 determines that a failure point has occurred behind the branch point 2a. As a result, even when a failure occurs behind, it is possible to calculate an accurate reactance in consideration of the leakage current I _ρ .

[3. Third embodiment]
The third embodiment will be described with reference to FIG. The third embodiment is the same as the second embodiment in basic configuration. Only differences from the second embodiment will be described, and the same parts as those of the second embodiment will be denoted by the same reference numerals and detailed description thereof will be omitted.

  FIG. 10 is a diagram showing an AC power transmission system to which the fault localization device according to the third embodiment is applied. The AC power transmission system according to the third embodiment includes a T-shaped power transmission line 2 having three sections 1 to 3 bordering on a branch point 2 a and AC power supplies 1 and 11. A basic line 21 connects the AC power source 1 and the AC power source 11, and a branch path 22 branches from a branch point 2 a of the basic line 21. The other end of the section 3 opposite to the branch point 2a is connected to another AC transmission line, an AC power supply, or a load.

  Section 1 is set between the AC power supply 1 and the branch point 2a, section 2 is set between the AC power supply 11 and the branch point 2a, and section 3 is set as the branch path 22. A reference end is provided for each of the sections 1 to 3. The reference end of section 1 is the end on the side of AC power supply 1, and the reference end of section 2 is the end on the side of AC power supply 11. The reference end of the section 3 is an end on the branch point 2a side.

FIG. 11 is a functional block diagram of the fault localization apparatus of the third embodiment. In the storage unit 35, the known line constants Z ₁ , Z ₂ , Z ₃ and the line angles k _θ1 , k _θ2 , k _θ3 in each of the sections 1 to ₃ and predetermined sections of each section used in the determination of the determination unit 37 are stored. The threshold is stored in advance. The quantity-of-electricity measurement unit 31 measures the currents I ₁ and I ₂ and the voltages V ₁ and V ₂ at the reference end in the sections 1 and ₂ .

As shown in FIG. 11, in the present embodiment, the fault localization apparatus includes a current / voltage calculation unit 38 that calculates the current I ₃ and the voltage V ₃ at the reference end in the section 3. The current / voltage calculation unit 38 calculates the currents I ₁ and I ₂ and the voltages V ₁ and V ₂ obtained by the electric quantity measurement unit 31 based on the following relational expression.
I ₃ = I ₁ + I ₂ (4)
V ₃ = (V ₁ −I ₁ · Z ₁ + V ₂ −I ₂ · Z ₂ ) / 2 (5)

The current I ₃ and the voltage V ₃ at the reference end of the section 3 may be measured by the electric quantity measuring unit 31 by providing a current detector and a voltage detector in the section 3.

The total current calculation unit 32, the current phase difference calculation unit 33, the voltage phase difference calculation unit 34, and the reactance calculation unit 36 perform calculation for each section. In particular, the reactance calculation unit 36 has, in each section, currents I ₁ , I ₂ , I ₃ and voltages V ₁ , V ₂ , V ₃ , both phase differences φ _f1 , φ _f2 , φ _f3 , φ _If1 at their reference ends. The line reactance from the reference end of each section to the failure point is calculated based on φ _If2 , φ _If3, line angles k _θ1 , k _θ2 , k _θ3 and the forward fault _localization formula (equation 1).

（数４）

（数５）

That is, the line reactance jX ₁ of section 1, determined by the following equation (3), the line reactance jX ₂ of section 2, determined by the following equation (4), line reactance jX ₃ sections 3, below ( It calculates | requires by Formula 5). Note that the reactance calculation unit 36 does not have to be provided with the rear failure point location calculation unit 36b.
(Equation 3)

(Equation 4)

(Number 5)

Here, the predetermined threshold value of each section used in the determination unit 37 stored in the storage unit 35 is that the section 1 is Z ₁ · sink _θ1 , the section 2 is Z ₂ · sink _θ2 , and the section 3 is Z _3. It is sink _θ3 .

The determination unit 37 determines as follows.
(1) In the case of jX ₁ ≦ Z ₁ · sink _θ 1, it is determined that the failure point is in the section 1 and the positioning value is jX ₁ .
(2) When jX ₁ > Z ₁ · sink _{θ 1} and jX ₂ ≦ Z ₂ · sink _θ 2, it is determined that the failure point exists in section 2 and the orientation value is set to jX ₂ .
_{(3) jX 1> Z 1} · sink θ1 _{and,, jX 2> Z 2 ·} sink θ2, and in the case of _{jX 3 ≦ Z 3 · sink θ3} , determines that the failure point is present in the section 3, the orientation value It is jX ₃ .
(4) In the case of jX ₁ > Z ₁ · sink _θ1 and jX ₂ > Z ₂ · sink _θ2 and jX ₃ > Z ₃ · sink _θ3 , the failure point is the outside of section 3, that is, the reference end of section 3 From the point of view, it is determined that it exists on the side opposite to the branch point 2a, and the orientation value is invalidated.

  As described above, according to the present embodiment, even if the power transmission line 2 has a plurality of power transmission lines, it can be determined in which section a failure point has occurred, and its effective positioning value Can be sought.

  As a modification of this embodiment, calculation of the line reactance in the sections 1 to 3 is performed in parallel, and the determination unit 37 determines that the calculated line reactance of the sections 1 to 3 is within the predetermined threshold of the sections 1 to 3 In this case, it may be determined that a failure point has occurred in the sections 1 to 3. Further, the determination of the determination unit 37 may be ended when the sections 1 to 3 in which the failure point has occurred are specified.

[4. Other Embodiments]
While several embodiments of the present invention have been described herein, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. The embodiment as described above 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 the equivalents thereof as well as included in the scope and the gist of the invention.

  For example, in the second embodiment and the third embodiment, an example in which the number of branch points 2a is one is described. However, the failure point localization device is applied even to the power transmission line 2 having two or more branch points. Is possible. In the third embodiment, the transmission line 2 has one T-shaped transmission line. However, the fault localization apparatus can be applied even if there are two or more transmission lines.

1, 11 AC power supply 2 transmission line 2a branch point 21 basic line 22 branch

Claims (6)

A fault localization apparatus for locating a fault point of a transmission line, comprising:
An electric quantity measuring unit for measuring the current and voltage at the reference end of the transmission line, and the leakage current flowing through the failure point;
A total current calculation unit that calculates a total current obtained by adding the current at the reference end and the leakage current;
A current phase difference calculating unit that calculates a phase difference between the current at the reference end and the total current;
A voltage phase difference calculation unit that calculates a phase difference between the voltage at the reference end and the total current;
A storage unit in which line angles of the power transmission line are stored in advance;
A reactance calculation unit that calculates a line reactance from the reference end to the failure point based on the current and voltage at the reference end, both the phase difference, and the line angle;
A failure point locating device comprising: The transmission line includes a basic line having the reference end and a branch point, and a branch path branched from the basic line at a branch point.
The reactance calculation unit includes:
A forward fault orientation calculating unit that calculates the line reactance based on a forward fault orientation formula that locates a failure point that has occurred in front of the reference end when viewed from the branch point;
If the value calculated by the forward failure localization calculation unit is within the predetermined threshold, it is determined that a failure point has occurred in the forward direction, and the value calculated by the forward failure localization calculation unit is greater than the predetermined threshold. If there is, including a determination unit that determines that a failure point has occurred in the rear other than the front,
The fault localization apparatus according to claim 1, characterized in that In the storage unit, a line constant between the reference end and the branch point is stored in advance,
The reactance calculation unit
A rear fault localization calculation unit that calculates the line reactance based on the line constant and a rear fault localization formula that locates the fault point that has occurred at the rear;
The rear fault orientation calculation unit, when the determination unit determines that a fault point has occurred behind the branch point, to calculate the line reactance based on the rear fault orientation formula,
The fault localization apparatus according to claim 2, wherein The power transmission line has a T-shaped power transmission line having first to third sections with the branch point as a boundary, and is located at an end opposite to the branch point of the first section and the second section. Are connected to AC power supply,
Each of the first to third sections has the reference end,
The total current calculation unit calculates the total current in each of the sections,
The current phase difference calculation unit calculates a phase difference between the current at the reference end and the total current in each of the sections,
The voltage phase difference calculation unit calculates a phase difference between the voltage at the reference end and the total current in each of the sections,
The line angle, the line constant, and the predetermined threshold value in each section are stored in advance in the storage unit, respectively.
The reactance calculation unit calculates a line reactance from the reference end to the fault point based on the current and voltage at the reference end, both the phase difference, and the line angle in each of the sections,
The determination unit is
When the calculated line reactance of each of the sections is within the predetermined threshold of each of the sections, it is determined that a fault point has occurred in the section;
The fault localization apparatus according to claim 2, wherein A fault point locating method for locating a fault point of a transmission line, comprising:
An electric quantity measuring step for measuring a current and a voltage at a reference end of the transmission line, and a leakage current flowing through the failure point;
A total current calculation step of calculating a total current obtained by adding the current at the reference end and the leakage current;
A current phase difference calculating step of calculating a phase difference between the current at the reference end and the total current;
A voltage phase difference calculating step of calculating a phase difference between the voltage at the reference end and the total current;
A reactance calculation step of calculating a line reactance from the reference end to the failure point based on the current and voltage at the reference end, the phase difference between the two, and the line angle of the power transmission line;
A failure point locating method characterized by comprising: A fault point localization program for locating a fault point of a transmission line, comprising:
On the computer
An electric quantity measurement process for measuring the current and voltage at the reference end of the transmission line, and the leakage current flowing through the failure point;
A total current calculation process for calculating a total current obtained by adding the current at the reference end and the leakage current;
Current phase difference calculation processing for calculating a phase difference between the current at the reference end and the total current;
Voltage phase difference calculation processing for calculating a phase difference between the voltage at the reference end and the total current;
Reactance calculation processing for calculating a line reactance from the reference end to the failure point based on the current and voltage at the reference end, both phase differences, and a line angle of the transmission line;
To run
Fault location program characterized by

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