JP3345751B2 - Distribution line fault direction locating method, locating device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for locating a fault direction in a distribution line, and more particularly to a method for locating a fault in an overhead distribution line in which a neutral point of a supply-side transformer, which is usually called a grounding system, is resistance-grounded. It relates to one used to locate the direction of failure when it occurs.

[0002]

2. Description of the Related Art A current transformer is attached to an overhead ground line of a transmission line of a resistance grounding system, and a current waveform at the time of failure is transmitted to an electric substation.
The position of the fault can be determined by computer processing of the magnitude and phase.

[0003] For example, three optical CTs are attached to three phases of a 6 kV distribution line, and outputs thereof are added to generate a zero-phase current. When the zero-phase current increases, this is detected as a ground fault and the optical C
When the output of each of the three Ts increases, this can be detected as a short-circuit fault.

In addition, three current transformers called ZCTs are attached to the three phases of the 6 kV distribution line, and when the added output of the outputs increases, this is detected as a ground fault and the output of each current transformer increases. Sometimes this can be detected as a short-circuit fault.

Further, a magnetic field sensor for detecting by electromagnetic induction is installed at a position sufficiently far from the three-phase 6 kV distribution line, and the increase in the output of the magnetic field sensor is detected as a zero-phase current. Failures can also be detected.

[0006]

By the way, a method for installing a current transformer on an overhead ground wire of an arbitrary power pole of an overhead distribution line is as follows.
The current transformer is susceptible to direct lightning strike, which may cause malfunction or destruction of the locator. In addition, the ground fault current is shunted to the ground of the power pole and the power supply side and the load side of the overhead ground wire by the faulty power pole, and the detection of the overhead ground wire current is difficult because the current is weak. Therefore, this method can be used for 200 to 30
It is suitable for a system in which a ground fault current of 0 A flows.
It is not suitable for a system in which the ground fault current of the 0 kV class (22 kV and 33 kV) overhead distribution line is several A to several tens A.

In addition, the method of directly installing three optical CTs on the three phases of the distribution line of an arbitrary power pole of an overhead distribution line requires a cost because consideration must be given to the withstand voltage and protection of the distribution line at the optical CT mounting part. Bulk and power outage work is required.

Further, the method of installing a current transformer called ZCT on a distribution line of an arbitrary power pole is not only expensive and requires a power outage work, but also because of the large size of the current transformer, aesthetically pleasing. Easy to lose.

Further, a method of installing a coil for detecting current by electromagnetic induction, that is, a sensor called a magnetic field sensor, at a position farther than a distribution line of an arbitrary pole, for example, at a ground leg of the pole, uses a 6 kV distribution line. And 100V, 200V
It can not be detected disabilities land絡故of overhead distribution lines since it greatly influenced by the load current flowing in the distribution line.

Accordingly, the present invention provides a non-contact type sensor that does not require a sensor to be installed directly on an overhead ground wire or a distribution line. There is no fault direction locating method and the same locating device.

[0011]

According to a first aspect of the present invention, there is provided a method for locating a fault direction in a distribution line, the method comprising the steps of: of an electric field magnetic field sensor with combined electric and magnetic field non-contact detection to distribution lines that constitute the distribution line of the phenomenon, by two arbitrary and multiple utility pole of the supply-side substation single-ended system overhead distribution lines disposed , of the electric field magnetic field sensor output
Increase of zero-sequence current due to addition of two magnetic fields and the above electric field
Upon detecting a <br/> increase pressure of zero-phase voltage by the addition of two field portions of the magnetic field sensor output, the supply with the demand side than the electric pole becomes the power supply direction away from the supply side electric station test that the ground fault failure occurs in the side electric station one end ground-based overhead distribution line
Characterized by knowing

According to a second aspect of the present invention, there is provided a distribution line fault direction locating apparatus which measures the electric field and magnetic field phenomena when a failure occurs in a distribution line to achieve the above object. the field magnetic sensor with combined electric and magnetic field non-contact detection to make distribution lines, as well as arranged by two in any and multiple utility pole of the supply-side substation single-ended system overhead distribution lines, ground fault failure above comprising a locating means for detecting that occurs in one of the supply-side substation single-ended system overhead distribution lines, target constant means, the electric field magnetic field sensor output
Increase of zero-sequence current due to addition of two magnetic fields and the above electric field
Upon detecting a <br/> increase pressure of zero-phase voltage by the addition of two field portions of the magnetic field sensor output, the supply with the demand side than the electric pole becomes the power supply direction away from the supply side electric station Side electric station
Test that the ground fault failure occurs in the single-ended system overhead distribution line
Is characterized in that the one that knowledge.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view of an overhead distribution line, in which 1 is a transmission transformer for an electric substation, 2 is its neutral point resistance, 3 is an electric substation on the demand side, and 4 is an overhead distribution line (hereinafter, there is no special requirement). 5 indicates a ground fault point, 6 indicates a ground fault current, that is, a manner in which a zero-phase current flows from the distribution line 4 through the ground to the neutral point resistor 2 to the power transmission transformer 1, and 7a and 7b are failure direction locating devices. FIG. 2 is a schematic diagram showing the appearance of short-circuit faults in an overhead distribution line, where 4a, 4b, and 4c are three-phase overhead distribution lines, 8 is a short-circuit fault point, and 9 is a distribution line 4b passing through the distribution line 4c. This shows the flowing short-circuit current.

FIG. 3 shows the fault direction locating device 7 shown in FIG.
5A and 5B are schematic views showing a state in which a pair of non-contact electric field magnetic field sensors (hereinafter, referred to as "electric field magnetic field sensors") 14 constituting the electric pole 10 are arranged on a power pole 10, in which 10 is a power distribution pole, 11 is an insulator, and 12 is fictitious. It is a ground line.

FIG. 4 is a schematic diagram showing the configuration of the electric field magnetic field sensor 14. The electric field sensor 14 is attached to an arbitrary pole member 40 of a distribution line at a position beside or below the three-phase overhead distribution lines 4a, 4b, 4c, and an electric field electrode plate 141 for detecting a voltage aspect by electrostatic induction; A magnetic field air-core coil 142 that detects aspects by electromagnetic induction is integrated, an electric wire 143 that sends those detection signals to the orientation device 15, and a metal fitting 144 for fixing the sensor box are provided. The failure direction is determined by non-contact detection.
Specifically, the electric field transmits electric potential information between the electric field electrode plate 141 and the ground to the orientation device 15 via the electric wire 143. Also,
As for the magnetic field, the information detected by the magnetic
At 43, it is transmitted to the orientation device 15. The magnetic field air core coil 142 is located inside the sensor box and is mounted on the inner wall side as shown in FIG. Further, the electric field electrode plate 141 forms a part of the sensor box.

In this embodiment, a pair of electric field magnetic field sensors 14
a, 14b, the upper electric field magnetic field sensor 14a is disposed closer to the distribution line 4a than the center of the overhead distribution lines 4a, 4b, and the lower electric field magnetic field sensor 14b is disposed closer to the distribution line 4c than the center of the distribution lines 4b, 4c. By installing it close to and keeping a safe distance from the transmission voltage, the zero-sequence current and zero-sequence voltage required for orientation can be obtained, enabling ground-fault current detection and ground-fault voltage detection during a ground fault. There is an arrangement to do. This arrangement also enables short-circuit current detection and power transmission interruption detection. The influence of the voltage due to the 6 kV distribution line 13 has lost sensitivity due to the shape of the electric field electrode plate 141, and the overhead distribution lines 4a, 4b, 4c
Is 22kV or 33kV distribution line and 6kV distribution line 13
, And the 6 kV distribution line 13 is not affected by being located further away. In addition, the influence of the electric current is 6 k
6k that the direction is not sensitive to the V distribution line 13
Since the phase becomes zero-phase with respect to the V distribution line 13 and the distance is further increased, the influence of the load current can be said to be very small, so that it is not affected. That is, it is possible to detect only a failure phenomenon that occurs in the distribution lines 4a, 4b, and 4c. FIG. 6 shows a positional relationship between the electric field sensors 14a and 14b. The relationship between the intervals D1, D2, D3 is:

(Equation 1) It is.

A description will now be given of the fact that the zero-phase voltage and the zero-phase current can be detected by adding the outputs of the electric field magnetic field sensors 14a and 14b. FIG. 5A is a vector diagram of voltages E1a, E1b, and E1c generated in the magnetic field coil 142 of the electric field sensor 14a by the currents Ia, Ib, and Ic of the distribution lines 4a, 4b, and 4c. Voltage E
1a, E1b, and E1c are the magnetic field coils 1
42 is output. Similarly, a vector diagram of the electric field magnetic field sensor 14b is shown in FIG. Voltage E2a, E
2b and E2c are currents Ia and Ia of distribution lines 4a, 4b and 4c, respectively.
b and Ic are voltages generated in the magnetic field coil 142, and E2 is a vector sum thereof. Vector sum E1, E
The electric field sensors 14a and 14b are installed at positions where the sizes of the two are equal and the directions are opposite. In this case, the vector sum of the vector sums E1 and E2, that is, the sum of the two voltages is zero when the system of the distribution lines 4a, 4b, and 4c is healthy. When one of the distribution lines 4a, 4b, and 4c is grounded (when a single line is grounded), a zero-phase current having the same phase as the current flows, and the sum of the voltages of the electric field magnetic field sensors 14a and 14b is It does not become zero.

FIG. 7 shows the electric field magnetic field sensors 14a, 1
4b is a circuit block diagram showing an electric circuit of the orientation device 15 for processing the output of FIG. 4b.
By integrating the electric field detected at 41, that is, the differential waveform, the waveform is made equal to the power transmission voltage. Similarly,
Since the magnetic field detected by the magnetic field air core coil 142 is also a differential waveform, it is integrated by the magnetic field integration circuit 24 to have a waveform equal to the transmission current. The amplifying circuits 17 and 25 are circuits for amplifying output signals of the electric field integration circuit 16 and the magnetic field integration circuit 24 to have appropriate signal magnitudes in order to facilitate processing in a subsequent circuit. The relay coil 33 and the relay contact 34 are for outputting the detected content of the orientation device 15 to the outside. The operation switch 36 is used for initial settings when the CPU 32 is activated, for viewing data contents at the time of orientation, and the like. The liquid crystal display 37 displays the content of the command operated by the operation switch 36. The stabilizing power supply 35 is for setting the power input to, for example, AC 100 V, or the power input from a solar cell or the like to, for example, DC 5 V required by an electronic circuit.

The detected contents and operation of the orientation device 15 having the above configuration will be described below. When a one-line ground fault 5 occurs in the distribution line shown in FIG. 1, the fault direction locating device 7a on the substation 1 side detects the fault phenomenon by the electric field magnetic field sensors 141 and 14b. The signal indicating the detection of the failure phenomenon is amplified by the amplifier 17 via the electric field integration circuit 16 and is analog-added by the analog addition circuit 18. The output obtained by the analog addition is usually close to 0 V due to the zero-phase voltage, but when a single-line ground fault occurs, one of the three-phase distribution lines 4a, 4b, and 4c becomes a large earth phase, so that the two-phase And the output is large. The increased signal is detected by the upper limit detection circuit 19 and the timer circuit 20 is started. The timer time is set to, for example, 10 seconds to detect that a ground fault has occurred somewhere. The failure direction locating device 7b on the demand side, which is the leading side in the power supply direction from the power transmission transformer 1 of the electric station, is similarly detected,
Perform operations such as amplification.

After the occurrence of the ground fault, the electric power station 1 cuts off the power transmission within, for example, 5 seconds after the occurrence of the ground fault to protect the power transmission equipment. Then, the transmission voltage disappears, and the detection outputs of both the two electric field magnetic field sensors 14a and 14b disappear. This is detected by the lower limit detection circuit 21 and the two electric field magnetic field sensors 1
4a, 14? AND circuit 2
2 and the timer circuit 23 outputs a signal indicating this for, for example, 10 seconds. The detection of the disappearance of the transmission voltage may be detected by one sensor output. However, when one line ground fault occurs, the phase becomes the ground potential and cannot be distinguished from the power transmission interruption. The detection is ensured by taking the AND condition of the output.

In the state shown in FIG. 1, the fault direction locating device 7a supplies the ground fault current 6 to the electric field magnetic field sensors 14a, 14a.
Detected by the air core coil 142 of b and output. This signal is amplified by the amplification circuit 25 and added by the analog addition circuit 26 to generate a zero-phase current. This analog addition output is usually 0V
, And becomes large when the ground fault current 6 flows. The signal is detected by the upper limit detection circuit 27, and the timer circuit 28 is started. The timer circuit 28 outputs a signal indicating this for, for example, 10 seconds. Of course, since the locating device 7b located at the point where the ground fault current 6 does not flow does not detect the ground fault current 6, the fault direction can be located.

When a short-circuit fault 8 occurs in the overhead distribution line as shown in FIG. 2, a fault direction locating device 7a on the substation 1 side
Is located at the location where the short-circuit fault current 9 flows, so that the current detected by the magnetic field air-core coil 142 of the electric field magnetic field sensors 14a and 14b is detected by the upper limit detection circuit 29, respectively. The timer circuit 31 is activated upon detection at 30. The timer circuit 31 outputs, for example, for 10 seconds. Of course, the locating device 7b located at the place where the short-circuit fault current 9 does not flow is the short-circuit fault current 9
Since no detection is performed, the fault direction can be located.

The CPU 32 is informed that the output of the timer circuit 20 is grounded somewhere in the overhead distribution line 4,
The output of the timer circuit 23 notifies that power transmission has been interrupted after the occurrence of a fault, the output of the timer circuit 28 indicates that a ground fault current has been detected, and the output of the timer circuit 31 indicates that a short-circuit fault current has been detected. The CPU 32 is turned off in a normal state where there is no failure.
It is turned on by the output of 0, 23, 28, 31 and performs predetermined data processing. That is, when only the output of the timer circuit 23 is input, the recording of the orientation time and the output of one relay are performed. When the outputs of the timer circuit 20 and the timer circuit 23 are input, the two relay outputs are recorded by recording the standardization time and the occurrence of the ground fault on the power source side (in the illustrated example, the power transmission transformer 1 side). Do. When the outputs of the timer circuits 20, 23, and 28 are input, three relay outputs are performed by recording the standardization time and the occurrence of the ground fault on the load side (the electric power station 3 side in the illustrated example). When the outputs of the timer circuits 23 and 31 are input, the fact that the short-circuit occurred at the orientation time and the load side is recorded, and two relay outputs are performed. And all timer circuits 20,
When the outputs 23, 28, and 31 are input, four relay outputs are performed by recording the grounding time and the ground fault short-circuit at the load side.

The relay output is used to transmit the contents of the orientation of the orientation device 15 to the office that manages the overhead distribution line, and in any section of the overhead distribution line, the monitoring computer provided in the administration office. It can be notified whether a ground fault or a short circuit fault has occurred. When data transmission is not to be performed, the user goes to the site where the failure has occurred and operates the operation switch 36 of the locating device 15 to display a message on the liquid crystal display 37. From the displayed content, the failure direction is determined on the power supply side or the load side. It is programmed so that you can determine if it has occurred. Since the contents of such a program are well known, description thereof will be omitted.

[0025]

The distribution line fault direction locating method according to the present invention,
Since the locating device is as described above, it is possible to reliably limit the ground fault fault section by installing a plurality of locating devices at appropriate positions on the single-sided grounding overhead distribution line on the power supply side. Thus, it is possible to quickly find a fault location with a small number of people, and to restore power transmission at an early stage.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing a state in which a ground fault has occurred in an overhead distribution line and an arrangement of a distribution line failure direction locating device in a distribution line failure direction locating method according to the present invention.

FIG. 2 is a conceptual diagram showing a state in which a short-circuit fault has occurred in an overhead distribution line and an arrangement of a distribution line failure direction locating device in a distribution line failure direction locating method according to the present invention.

FIG. 3 is a conceptual diagram showing a state in which two electric field magnetic field sensors and a locating device, which constitute one embodiment of a distribution line fault direction locating device according to the present invention, are arranged on electric poles at appropriate positions on an overhead distribution line.

FIG. 4 is a conceptual diagram illustrating a configuration of an electric field magnetic field sensor that detects voltage and current phenomena of an overhead distribution line as an electric field and a magnetic field.

5 is a vector diagram of a voltage generated in a magnetic field coil of the electric field magnetic field sensor shown in FIG. 4 by a current of an overhead distribution line.

FIG. 6 is a diagram showing a mounting position condition of the electric field magnetic field sensor shown in FIG.

FIG. 7 is a block diagram of a locating device which forms one embodiment of a distribution line fault direction locating device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transmission transformer of supply side electric station 2 Neutral point resistance 3 Demand side electric station 4, 4a, 4b, 4c Overhead distribution line 5 Ground fault point 6 Ground fault current 7a, 7b Fault direction locating device 8 Short-circuit fault point 9 Short-circuit fault current 10 Power distribution pole 11 Insulator 12 Overhead ground wire 136 kV distribution line 14, 14a, 14b Electric field magnetic field sensor 141 Electric field electrode plate 142 Magnetic field air core coil 143 Electric wire 144 Metal fitting 15 Location device 16 Electric field integration circuit 17 Amplification Circuit 18 Analog addition circuit 19 Upper limit detection circuit 20 Timer circuit 21 Lower limit detection circuit 22 AND circuit 23 Timer circuit 24 Magnetic field integration circuit 25 Amplifier circuit 26 Analog addition circuit 27 Upper limit detection circuit 28 Timer circuit 29 Upper limit detection circuit 30 OR circuit 31 Timer circuit 32 CPU (microcomputer) 33 relay coil 34 relay Contact 35 regulated power supply 36 operation switch 37 liquid crystal display 40 a utility pole

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Nobutaka Fukui 1-231, Fukudomeminami, Matsuto City, Ishikawa Prefecture (56) References JP-A-8-19633 (JP, A) JP-A-54-37236 (JP, A) JP-A-50-100558 (JP, A) JP 6-70665 (JP, B2) JP 8-33428 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01R 31/08 G01R 31/02 G01R 19/00

Claims (2)

(57) [Claims] 1. An electric field magnetic field sensor which combines an electric field and a magnetic field for detecting a phenomenon of an electric field and a magnetic field when a failure occurs in a distribution line in a non-contact manner with a distribution line forming the distribution line. each two placed on any and multiple utility pole grounding system overhead distribution lines, out increases and the field magnetic field sensor of the zero-phase current by the addition of two of the magnetic field of the electric field the magnetic field sensor output
Upon detecting the increase in the zero-phase voltage by the addition of two field portions of the force, the supply-side substation single-ended system by demand side than electric pole becomes the power supply direction away from the supply side electric station distribution line fault direction orientation wherein the detecting that the ground fault failure occurs in the overhead distribution lines. 2. An electric field magnetic field sensor which combines an electric field and a magnetic field for non-contact detection of a phenomenon of an electric field and a magnetic field when a failure occurs in a distribution line with the distribution line forming the distribution line, is provided at one end of a supply side electric station. as well as arranged one by two into any and multiple utility pole grounding system overhead distribution lines, ground fault failure comprises a locating means for detecting that occurs in one of the supply-side substation single-ended system overhead distribution lines, the locating means, increase及of two zero-phase current by the addition of the magnetic field of the electric field the magnetic field sensor output
And the two electric field parts of the output of the electric field magnetic field sensor
Upon detecting the increase of the zero-phase voltage pressurized, the test at the demand side than the electric pole becomes the power supply direction away from the supply side electric station
Distribution line fault direction orientation and wherein the the feed side substation single-ended system overhead distribution line is intended to detect that the ground fault failure occurs.