JPH0836017A - Device for locating failure block of transmission line - Google Patents

Abstract

PURPOSE:To provide a device for locating a failure block of a transmission line, which can locate the failure block without using a voltage sensor and which can locate the failure block at the time only when the failure has really occurred. CONSTITUTION:A central device stores values IOA, IOB of the zero phase currents at the time of failure, which are detected by current sensors 34, 35 and failure detecting devices 1, 2, and stores the phase phiOA, phiOB, and the detection time tOA, tOB. A central device 3 stores the failure-generated time tO, when supply of the current to a transmission line 33 is cut by a relay 61, and takes out the detection data dOA, dOB, which include the detection time tOA, tOB near the detected time tO, so as to locate the failure block.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a faulty section locating device for a power transmission line, and more particularly to a device for locating a faulty section when a fault occurs in a power transmission line divided into a plurality of sections.

[0002]

2. Description of the Related Art Conventionally, in a commercial power system, a failure section locating device for locating a failure section of a transmission line has been provided. In the conventional fault section locating device, a voltage sensor and a current sensor are provided at each of a plurality of points that divide the transmission line into a plurality of sections, and the zero-phase voltage and the zero-phase current at each point are detected. If the phase of the zero-phase voltage at that point leads the phase of the zero-phase current by 90 °, it is determined that the failure point is upstream (power station side) from that point, and conversely, that point. If the phase of the zero-phase voltage of is delayed by 90 ° from the phase of the zero-phase current, it is determined that the failure point is on the downstream side (customer side) of that point.
Therefore, by measuring the zero-phase voltage and the zero-phase current at all points and detecting the phase difference between them, it is possible to locate in which section of the transmission line the fault has occurred.

However, in the conventional fault zone locating device, the voltage sensor measures the divided voltage obtained by dividing the voltage between the transmission line and the ground by the predetermined capacitance of the capacitor and the ground capacitance. There was a problem that was unstable depending on the weather.

Therefore, the inventors of the present application filed Japanese Patent Application No. 5-06.
In 0217, a fault section locator that does not require a voltage sensor was proposed. FIG. 6 is a block diagram showing the configuration of the fault segment location device.

Referring to FIG. 6, this fault zone locating device has current sensors 34 provided at two points A and B of a transmission line 33 between an upstream substation 31 and a downstream substation 32. , 35, failure detection devices 36, 37 provided corresponding to the current sensors 34, 35, and a central device 38 for receiving the output of each failure detection device 36, 37.

As shown in FIG. 7, the power transmission line 33 is generally composed of three power transmission lines 33a, 33b, 33c.
As shown in FIG. 7 and FIG. 8, the current sensor 34 includes annular cores 41 a, 41 b, 41 c with gaps through which the transmission lines 33 a, 33 b, 33 c are inserted, respectively, and inside the gaps of the respective annular cores 41 a, 41 b, 41 c. Magnetic field sensors (Faraday elements) 42a, 42b, 42c provided in the
And The annular cores 41a, 41b, 41c focus the magnetic field generated by the currents of the power transmission lines 33a, 33b, 33c. The magnetic field sensors 42a, 42b, 42c output optical signals corresponding to the magnetic fields in the gaps of the annular cores 41a, 41b, 41c, that is, the currents of the power transmission lines 33a, 33b, 33c. The same applies to the current sensor 35.

The failure detection device 36, as shown in FIG.
O / E converters 51a, 51b, 51c, three-phase synthesis section 5
2. The O / E converters 51a, 51b and 51c including the filter unit 53 and the determination unit 54 are connected to the magnetic field sensor 43 via the optical fiber cables 43a, 43b and 43c, respectively.
It is connected to the output terminals of a, 43b, and 43c.

The O / E converters 51a, 51b and 51c are
The optical signals from the magnetic field sensors 43a, 43b, 43c are converted into electric signals and output to the three-phase combining section 52. The three-phase synthesis unit 52 obtains the sum (corresponding to a zero-phase current) of the electric signals from the O / E changers 51a, 51b, 51c, and outputs the electric signal to the filter unit 53. The filter unit 53 is
Noise is removed from the electrical signal and output to the determination unit 54.

The determination unit 54 determines the value I _0A of the zero-phase current and its phase φ _0A based on the output of the filter unit 53.
The phase difference between the output of the filter unit 53 and the output of the O / E converter 51c (corresponding to the current of the power transmission line 33c) is the phase φ _{0A of the} zero-phase current.

Further, the judging section 54 compares the zero phase current value I _0A obtained from the output of the filter section 53 with a predetermined threshold value I _th , and the zero phase current value I _0A is compared with the threshold value I _th. If it is larger than the above, it is determined that a failure (for example, a ground fault) has occurred,
The value I _0A of the zero-phase current and its phase φ _0A are output to the central unit 38. The same applies to the failure detection device 37.

The central unit 38 is the failure detection unit 36, 37.
Values of zero-phase current I _0A , I _0B and their phases φ _0A , φ
_The faulty section is located based on the magnitude relation of _0B . That is, the central unit 38 determines that a failure has occurred in the section X between the substation 31 and the point A when I _0A > I _0B and φ _0A = φ _0B , and I _0A <I _0B and φ _0A = In the case of φ _0B , it is determined that the failure has occurred in the section Z between the substation 32 and the point B. When φ _0A and φ _0B are different by 180 °, the failure occurs in the section Y between the point A and the point B. It is judged that it did.

The correlation between the magnitudes of the zero-phase current values I _0A and I _0B and their phases φ _0A and φ _0B and the fault occurrence sections X, Y and Z was obtained from the field test conducted by the inventors of the present application. It is a thing.

As described above, since the fault section locating device according to Japanese Patent Application No. Hei 5-060217 does not need a voltage sensor,
Unlike the conventional example, the measurement result does not depend on the weather.

[0014]

However, even in the fault section locating apparatus according to Japanese Patent Application No. 5-060217,
The following problems can be considered.

FIG. 9 is a diagram showing changes in the number of detected faults at points A and B when the threshold value I _th is changed from 0.15 (A) to 0.4 (A). As can be seen from FIG. 9, when the threshold value I _th is set small, the number of detected failures increases, and when the threshold value I _th is set large, the number of detected failures decreases.

This is because the fault current of the power transmission line 33 is usually about 0.08 (A / km), which is much smaller than the rated current flowing through the power transmission line 33 (about 1/1000).
That is, the currents of the three power transmission lines 33a, 33b, and 33c are independently detected and combined, and the zero-phase current values I _0A and I _{0 are obtained} .
_{Since 0B} is obtained, the zero-phase current values I _0A and I _0B exceed the threshold value I _th even when there is no failure due to fluctuations in the load current of the transmission line 33 (level fluctuations, frequency fluctuations). is there. If the threshold value I _th is further increased, it is possible to eliminate the failure detection except when a failure occurs, but on the contrary, it becomes difficult to detect the failure when an actual failure occurs.

Therefore, a main object of the present invention is to provide a faulty section locating device for a transmission line which does not require a voltage sensor and can locate a faulty section only when a failure actually occurs.

[0018]

Means for Solving the Problems A faulty section locating device for a power transmission line according to the present invention is provided at each of a plurality of points that divide the power transmission line between an upstream substation and a downstream substation into a plurality of sections. A plurality of zero-phase current detecting means for detecting the value of the zero-phase current at that point and its phase, and zero phases detected by the zero-phase current detecting means respectively provided corresponding to the zero-phase current detecting means. A plurality of storage means for storing detection data including the zero-phase current value, its phase, and detection time when the current value exceeds a predetermined threshold value; and the upstream substation. A plurality of storages that store a failure occurrence notification unit that outputs a failure occurrence signal in response to a failure current flowing through the power transmission line, and a failure occurrence time at which the failure occurrence notification unit outputs the failure occurrence signal. Memorized by means And a processing unit for locating a section in which a failure occurs from the detected data by retrieving the detected data and extracting the detected data including the detection time whose time difference from the failure occurrence time is within a predetermined range. It is characterized by that.

Further, the arithmetic processing means includes a clock for reading the failure occurrence time, and each of the storage means is a clock for reading the detection time driven in synchronization with the clock of the arithmetic processing means. May be included.

[0020]

In the transmission line fault zone locating device according to the present invention, the storage means provided corresponding to the zero-phase current detecting means at a plurality of points of the transmission line are the values of the zero-phase current at the points. Stores the detection data including the value of the zero-phase current, its phase, and the detection time in response to the threshold value exceeding the predetermined threshold value. The arithmetic processing means stores the failure occurrence time at which the failure actually occurred, retrieves the detection data including the detection time close to that time from the storage means, and locates the failure section from the detection data. Therefore, the voltage sensor is not required, and the fault section can be located only when the fault actually occurs.

Further, by providing a clock in each of the storage means and the arithmetic processing means and synchronizing those clocks, it is possible to prevent the time from being shifted in each of the storage means and the arithmetic processing means, and the failure occurrence time. It is possible to accurately extract the detection data including the detection time close to.

[0022]

1 is a block diagram showing the configuration of a faulty section locating device for a transmission line according to an embodiment of the present invention. FIG.
With reference to FIG. 2, the fault location device is provided with current sensors 34 and 35 provided at two points A and B of a transmission line 33 between an upstream substation 31 and a downstream substation 32, respectively.
And failure detection devices 1 and 2 provided corresponding to the respective current sensors 34 and 35, and a central device 3 provided in the upstream substation 31. In addition, the upstream substation 31 is provided with a relay 61 that cuts off the supply of current to the power transmission line 33 in response to a fault current flowing through the power transmission line 33.

As shown in FIG. 2, the failure detection device 1 has an O
/ E converters 51a, 51b, 51c, including a three-phase combining section 52 and a filter section 53, and O / E converters 51a, 51
b and 51c are optical fiber cables 43a, 43b and 43
the magnetic sensors 42a, 42 of the current sensor 34 via c
It is connected to the output terminals of b and 42c. For these,
Since it is the same as that shown in FIG. 7, its explanation is omitted.

Further, the fault section locating device 1 includes an arithmetic processing section 4, a storage section 5 and a clock 6. The arithmetic processing unit 4 obtains the value I _0A of the zero-phase current and its phase φ _0A based on the output of the filter unit 53. The phase difference between the output of the filter unit 52 (corresponding to the zero-phase current) and the output of the O / E converter 51c (corresponding to the current of the power transmission line 33c) is the phase φ _{0A of the} zero-phase current.

Further, the arithmetic processing section 4 has a value I _0A of the zero-phase current obtained from the output of the filter section 53 and a predetermined threshold value I _th.
When the value I _0A of the zero-phase current is larger than the threshold value I _th , it is determined that a failure has occurred, and the value I of the zero-phase current I
_The detection data including _0A , its phase φ _0A, and time t _{0A at} that time is stored in the storage unit 5. The time t _0A is read from the clock 6.

Further, the arithmetic processing section 4 fetches the detection data from the storage section 5 in response to a command from the central unit 3 and sends it to the central unit 3. Further, the arithmetic processing unit 4 sets the time of the timepiece 6 according to the instruction from the central unit 3.

As shown in FIG. 3, the central unit 3 includes an arithmetic processing unit 7, a storage unit 8 and a clock 9. The arithmetic processing unit 7 is connected to the relay 61 and the failure detection devices 1 and 2 by wire or wirelessly.

The arithmetic processing unit 7 periodically polls the failure detection devices 1 and 2, collects detection data if any, and stores it in the storage unit 8. The polling is performed at time intervals in which the amount of detected data does not exceed the capacity of the storage unit 5 of the failure detection device 1 or 2.

Further, the arithmetic processing unit 7 stores the time t ₀ in response to the operation of the relay 61, and locates the fault section. The fault segment is located as follows.

(1) The detection data stored in the storage unit 8 is searched and the detection times t _0A and t closest to the failure occurrence time t _0.
The detection data d _0A and d _0B including _0B are extracted.

(2) If the difference between the detection times t _0A and t _{0B of the fetched} detection data d _0A and d _0B and the failure occurrence time t ₀ is larger than a predetermined time σ (sec), it is judged as a detection error.

(3) Detection data d_0A, D_0BZero-phase current of
The value of_0A, I_0BAnd its phase φ_0A, Φ_0BIs it big or small
The faulty section is located. Ie I_0A> I_0BAnd
φ_0AAnd φ_0BIf the difference is less than 90 °, the fault occurs in section X.
I judged that it was born, I_0A<I _0BAnd φ_0AAnd φ_0BDifference
If is less than 90 °, it is determined that a failure occurred in section Z.
, Φ_0AAnd φ_0BIf the difference between is greater than 90 °, the interval
It is determined that a failure has occurred in Y.

Further, the arithmetic processing section 7 includes the failure detection device 1,
The timepiece 6 of the failure detection devices 1 and 2 is synchronized with the timepiece 9 of the central device 3 so that an error of the timepiece 6 does not occur between the two.

FIG. 4 is a flow chart showing the operation of the arithmetic processing section 7. The arithmetic processing unit 7 normally performs a main process including steps (abbreviated as S in FIG. 4) S1 to S10, and in response to the relay 61 cutting off the supply of current to the power transmission line 33, step S11. , S12 including the failure occurrence interrupt processing. The arithmetic processing unit 7 includes a relay 61
In response to the interruption of the current supply to the power transmission line 33, the time t ₀ is stored in step S11, and the failure occurrence flag is set in step S12.

Further, the arithmetic processing section 7 determines whether or not a failure has occurred in step S1 and, in response to the occurrence of a failure (a failure flag is set),
In step S2, the detection data in the storage unit 8 is searched,
The data d _0A and d _0B including the detection times t _0A and t _0B close to the failure occurrence time t ₀ are taken out, and the orientation process is performed by the above-mentioned method in step S3.

In response to the end of the orientation processing or the failure not occurring in step S1 (the failure flag was not set), the arithmetic processing section 7 polls the time in step S4. Do. That is, the time is periodically read from the clock 9. Next, the arithmetic processing unit 7 determines in step S5 whether or not the processing time is reached, and depending on the processing time, the detection data is collected from the failure detection devices 1 and 2 (step S6). A process of synchronizing the second clock 6 (step S7) and a storage management of the collected detection data (step S8) are performed.

In response to the completion of these processes (steps S6 to S8) or the processing time not being reached in step S5, the arithmetic processing section 7 determines whether or not the menu is selected in step S9. Determine whether. When the menu is selected, the arithmetic processing unit 7
Performs processing (for example, data display) according to the menu in step S10. In response to the completion of the processing, or in response to the selection of the menu in step S9, the arithmetic processing unit 7
Return to step S1.

FIG. 5 is a block diagram illustrating a specific configuration of the fault section locating device shown in FIGS. Referring to FIG. 5, in this fault location device, personal computers 12 and 13 are provided in unattended substation 31 and manned power station 70, respectively. The personal computer 12 constitutes the central device 3, and the personal computer 13 constitutes a display device for displaying the orientation result of the personal computer 12. The personal computers 12, 13 and the detection devices 1, 2 are connected to a telephone line 71 via a modem (modulation / demodulation device) 14. UPS (uninterruptible power supply) is used for the personal computers 12 and 13 and the modem 14 for the personal computers 12 and 13.
Power is supplied from 15. Further, the relay operation signals of the ground fault relay 62, the fine ground fault relay 63 and the short circuit relay 64 of the substation 31 are input to the personal computer 12 via the voltage converter 10 and the DI port (digital input port) 11. The voltage converter 10 steps down the relay operation signal of 55 (V) to 24 (V). DI port 11
Is an insulation type in which the input and output ends are coupled by a photocoupler.

Next, the operation of the fault zone locating device of FIG. 5 will be described. The personal computer 12 periodically polls the failure detection devices 1 and 2 via the telephone line 71, and collects and stores the detected data, if any. Power transmission line 3
A fault current flows in 3 and a ground fault relay 62, a fine ground fault relay 6
3 or the short circuit relay 64 operates, the relay 6
A relay operation signal is input to the personal computer 12 from 2, 63 or 64.

The personal computer 12 stores the time t ₀ to the relay operation signal is input, the detection time close to the time t ₀ t _0A, detection data d _0A containing t _0B, taken out d _0B, the detected data The fault section is located based on d _0A and d _0B . The personal computer 12 transmits the orientation result to the personal computer 13 of the power station 70 via the telephone line 71.

The personal computer 13 notifies the occurrence of a failure to the power station 70 by means of a notification means (for example, a buzzer) and also displays the failure section on the display screen. The worker in the power station 70 detects the occurrence of a failure and the failure section from the display screen of the personal computer 13 and proceeds to the failure recovery work.

[0042]

As described above, according to the present invention, the detection data including the value of the zero-phase current at the time of failure detection, its phase, and the detection time is stored in the storage means, and the failure actually occurs. At that time, the detection data including the detection time close to that time is taken out from the storage means, and the failure section is located based on the detection data. Therefore, the voltage sensor is not required, and the fault section can be located only when the fault actually occurs.

Further, if clocks are provided in each of the storage means and the arithmetic processing means and the clocks are synchronized with each other, it is possible to prevent the time from being shifted in each of the storage means and the arithmetic processing means, and the failure occurrence time can be prevented. It is possible to accurately extract the detection data including the detection time close to.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a faulty section locating device for a transmission line according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a fault detection device of the fault section locating device shown in FIG.

FIG. 3 is a block diagram showing a configuration of a central device of the fault section locating device shown in FIG.

FIG. 4 is a flowchart showing an operation of an arithmetic processing unit of the central apparatus shown in FIG.

5 is a block diagram illustrating a specific configuration of the fault section locating device shown in FIG.

FIG. 6 is a block diagram showing a configuration of a conventional faulty section locating device for a transmission line.

FIG. 7 is a block diagram showing a configuration of a failure detection device of the failure section locator shown in FIG.

FIG. 8 is a partially cutaway perspective view showing a configuration of a current sensor of the fault section locating device shown in FIG.

9 is a diagram for explaining the problem of the fault section locating device shown in FIG. 6, and is a diagram showing the relationship between the threshold value of the zero-phase current and the number of detected faults.

[Explanation of symbols]

 1 and 2 failure section locator 3 central apparatus 4 and 7 arithmetic processing section 5 and 8 storage section 6 and 9 clock 31 and 32 substation 33 transmission line 34 and 35 current sensor 61 to 64 relay A and B points X and Y, Z section

Claims (2)

[Claims] 1. A plurality of power transmission lines between an upstream substation and a downstream substation, each of which is provided at a plurality of points that divide the transmission line into a plurality of sections, and which detects a zero-phase current value and a phase thereof at the points. Zero-phase current detection means, each provided corresponding to the zero-phase current detection means,
In response to the value of the zero-phase current detected by the zero-phase current detecting means exceeding a predetermined threshold value, a plurality of detection data including the value of the zero-phase current and its phase and the detection time are stored. Storage means, failure occurrence notification means provided in the upstream substation and outputting a failure occurrence signal in response to a failure current flowing through the power transmission line, and the failure occurrence notification means outputs the failure occurrence signal The failure occurrence time is stored, the detection data stored in the plurality of storage means is searched, and the detection data including the detection time whose time difference from the failure occurrence time is within a predetermined range is taken out.
An arithmetic processing unit for locating a section in which a failure has occurred from the detected data, and a faulty section locating device for a transmission line. 2. The arithmetic processing means includes a clock for reading the failure occurrence time, and each of the storage means is a clock for reading the detection time driven in synchronization with the clock of the arithmetic processing means. The fault section locating device for a power transmission line according to claim 1, comprising: