JP2003302440A - Failure section locating method and failure section locating system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a failure section locating method and a failure section locating system capable of locating easily a failure point of a one-circuit short- circuit accident in a two-circuit transmission line by using only one kind of sensor. <P>SOLUTION: In this failure section locating method and this failure section locating system, a method is used, for locating in a section unit, a one-circuit short-circuit accident generated in a two-circuit juxtaposing transmission line quipped with a first transmission line 31 and a second transmission line 32 which are parallel two circuits for connecting parallel connection points 53, 54 of on the upstream side 51 and downstream side 52. In the failure section locating method, a failure can be easily determined by paying attention to an added value which is a value greatly different between the normal time and the failure time, and by determining to be a failure when the value falls in a range determined beforehand. In addition, it can be determined that the interval between a dead spot 7 determined to be a failure and an operating spot 8 which is not a failure positioned on the upstream side from the dead spot is a dead section. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fault zone locating method and a fault zone locating system capable of identifying a fault zone including a short-circuit fault point that occurs in two-line power transmission lines transmitting power in parallel. More specifically, the present invention relates to a failure section locating method and a failure section locating system capable of easily locating a failure section of a one-circuit short-circuit accident in a transmission line with two circuits using only one type of sensor.

[0002]

2. Description of the Related Art As shown in FIG. 4, transmission line towers 4a, 4
In a two-circuit combined transmission line that transmits power with redundancy by arranging two transmission lines 31 and 32 in parallel with b, 4c, ... Or a short circuit accident may occur. In the case of a short-circuit accident in a transmission line composed of only one line, a short-circuit current flows upstream from the failure point, but no current flows downstream from the failure point, so current sensors are installed at intervals and The faulty section including the faulty point can be easily discriminated by whether or not it is flowing. However, in the case of 1-circuit short-circuit accident of 2-circuit power transmission,
As shown in FIG. 4, the current flowing in the downstream 52 by the normal line flows backward from the parallel connection point 54 through the faulty second transmission line 32 and flows as the current 62 to the fault point P. It cannot be used.

As an orientation method for detecting a section in which a one-circuit short-circuit accident has occurred in such a two-circuit transmission line,
(1) A method is known in which a current sensor and a voltage sensor are installed in each line and the outputs of these are used to determine the direction of a failure point. Further, (2) Japanese Patent Laid-Open No. 5-203693 discloses a method in which a current sensor is arranged so that the sensitivity is high for one line, and a fault section can be located from the magnitude of the current of each line. Are listed. This method determines the direction of the failure point from the measurement point based on the difference in the phase of the current measured by each current sensor.

[0004]

However, in the method using the current sensor and the voltage sensor shown in (1), two types of sensors and amplifier circuits are required, resulting in high cost.
It is desired to have a method that uses only one type of sensor. Further, in the method using the difference in the phase of the current shown in (2), the current waveform is distorted by the harmonic component such as noise generated at the failure location, and the phases cannot be easily compared. There is a problem that it is difficult to determine. The present invention solves the above-mentioned problems, and a fault section locating method and fault section locating method capable of easily locating a fault point of a one-circuit short-circuit accident of a two-circuit power transmission line using only one type of sensor. The purpose is to provide a system.

[0005]

According to the fault zone locating method of the first aspect of the invention, at least one current sensor is provided for each line in a two-line power transmission line that transmits power in parallel.
When an overcurrent in which at least one output value of the current sensor exceeds a predetermined value is detected, a dead point at which the added value of the output values in each of the lines falls within a predetermined range, and an upstream of the dead point It is characterized in that it is determined as a failure section between the operating point on the side and the added value exceeding a predetermined range. Further, the above-described orientation can be performed when an overcurrent in which the output values of the current sensors in the both lines and in the same phase exceed a predetermined value is detected. Further, the predetermined value may be a ratio to the output of the current sensor at the same point.

In the fault section locating system according to the fourth aspect of the present invention, in a two-line power transmission line that transmits power in parallel, at least one current sensor is provided for each line and the outputs of the current sensors of each line are added. The two or more slave stations that output at least the added value and the master station that includes the fault section locating section that receives the added value output from the slave station and locates the fault section The failure section locator detects an overcurrent in which at least one output value of the current sensor exceeds a predetermined value, and the added value of the output values is less than or equal to a predetermined range. It is characterized in that a fault section is determined between the slave station at an operating point on the upstream side of the operating point and at which the added value exceeds a predetermined range.

[0007]

EFFECTS OF THE INVENTION According to the fault section locating method and the fault section locating system, the fault section of the one-circuit short-circuit fault can be located only by the current sensor, and the voltage sensor and the current direction discriminating circuit are unnecessary. Therefore, an inexpensive orientation system can be manufactured. Further, even if the waveform of the fault current is deformed by the harmonic component such as noise generated at the fault location or the like, the fault section can be easily located. Further, by limiting the location of the faulty section to the period during which the overcurrent is detected, it is possible to prevent erroneous detection of the fault.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The "current sensor" may be any type as long as it can measure an absolute value or a relative value of a current flowing through a power transmission line in a non-contact manner. An example of this is the use of a magnetic sensor that measures the magnetism generated with energization. Further, as the magnetic sensor, a method using a coil, a sensor using a Hall element or a magnetoresistive element, and the like can be exemplified.

Further, the number of current sensors can be any number. For example, the current flowing through multiple phases of the same line can be obtained with one current sensor. By determining the currents of a plurality of phases with one current sensor, it is possible to perform fault segment localization at low cost. In addition, one or more current sensors can be assigned to one phase for current measurement. As described above, by measuring each phase individually, the current can be measured with high accuracy, and the fault section can be easily located.

The above-mentioned predetermined value for detecting the overcurrent can be arbitrarily set within a range in which it can be distinguished from the load current. Also, the ratio to the output of the current sensor can be set arbitrarily. Further, the above-mentioned predetermined value in the added value can be set arbitrarily.
A value smaller than the current value due to overcurrent is preferable.

The above "slave station" is provided with a current sensor and an addition value output unit, but these may be provided integrally, or they may be provided separately and can be connected by wire or wirelessly. By making the current sensor and the additional value output part separate,
Since only the current sensor can be provided above the steel tower so as to approach the transmission line side and the additional value output unit can be provided at an arbitrary position of the steel tower, various workability such as installation work and inspection work can be improved.

1. Failure Section Locating Method The failure section locating method of the present invention is a parallel section 2 as shown in FIG.
A parallel connection point 53 of the upstream 51 and the downstream 52,
This is a method for locating a one-circuit short-circuit accident that has occurred in a two-circuit power transmission line provided with a first power transmission line 31 and a second power transmission line 32 that connect between 54 in section units. Also,
In this fault section locating method, one section is located between each of the steel towers 4a, 4b, 4c, ... Which perform the overhead line of the first transmission line 31 and the second transmission line 32, and each steel tower 4a, 4b, 4c ... 1st current sensor 11a, 11b, 11c ... for measuring the electric current which flows into the predetermined phase or phase group of a power transmission line is provided. Further, each of the steel towers 4a, 4b, 4c ... Is provided with second current sensors 12a, 12b, 12c ... For measuring a current flowing in a predetermined phase or phase group of the second power transmission line. Further, the outputs of the current sensors 11 and 12 are amplified by an addition value output section in the slave station 1 provided in the steel tower 8 and then added to each other to obtain an addition value.

(1) Normal time In a normal time when no short circuit accident occurs in the power transmission line, as shown in FIG. 3, the output values of the current sensors 11 and 12 of the respective power transmission lines 31 and 32 used for the added value are , Almost match. This is because the current sensors 11 and 12 are provided in the same steel tower 4, so that a phase shift or the like does not substantially occur, and different noise is unlikely to be included unlike when power is transmitted through a completely different route.
Further, as shown in FIG. 3, the added value of each line is a value obtained by superimposing each output value.

(2) At the time of failure Next, a state in which a one-circuit ground fault occurs at the failure point P of the second power transmission line 32 as shown in FIG. 4 will be described. When the ground fault occurs at the failure point P, the upstream side 51 of the first power transmission line 31
A short-circuit current 61 flows from the side to the failure point P. Further, the short-circuit current 62 flows from the parallel connection point 54 on the downstream 52 side of the second power transmission line 32 to the failure point P via the first power transmission line 31. The fault current 62 from the downstream is large enough to be detected, and its direction is clearly different from that of the current flowing from the upstream to the downstream.

For this reason, as shown in FIG. 3, upstream of the fault point P, current flows through the first power transmission line 31 and the second power transmission line 32 in the same direction, so that the output values of the current sensors 11 and 12 are normal. As in the case of the time, there is almost no phase shift, and they substantially coincide with each other. However, in the downstream of the failure point P, as shown in FIG. , 12 have different output values. For this reason, when the current sensor of each first power transmission line and the current sensor of the second power transmission line are added together, they cancel each other, so that the added value has a significantly smaller absolute value than in the normal state.

In the present fault segment location method, the fault is easily determined by focusing on the added value that greatly differs between the normal state and the fault state and determining the fault when it falls within a predetermined range. can do. Further, it is possible to determine as a failure section between the non-operation point 7 which is determined to be a failure and the non-fault operation point 8 which is upstream from the non-operation point.

Further, the determination of the failure based on the added value can be made by previously checking whether or not an overcurrent is flowing and only when the overcurrent is flowing. By checking whether or not the current is an overcurrent, it is not necessary to distinguish it from the current value at the normal time, and the condition of the determination process can be easily determined. Whether this is an overcurrent depends on the current sensor 1
It can be determined by checking whether the output values of 1 and 12 exceed the value of the current flowing when the load is normal. When a plurality of current sensors 11 and 12 are provided at one point of one line, the current sensor 1 of the phase for which the added value is obtained
It is determined from the current values of 1 and 12 whether it is an overcurrent.

Further, the range of the added value when it is determined that the failure has occurred can be calculated from the ratio to the output value of the current sensors 11 and 12 (either one may be used, or the average value of both may be used). For example, the ratio is 1/10 of the output value.
With this, it is possible to determine a failure when the added value becomes 1/10 or less of the output value. Even when a one-circuit short-circuit accident occurs in the second power transmission line, the fault segment location method can be applied in the same manner as described above. Further, as shown in FIG. 6, even when a short circuit accident between phases occurs, a current flowing back to the failure point P occurs downstream from the failure point P as in the case of the ground fault shown in FIG. , The same fault segment location method can be used to locate the fault segment.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the fault zone locating method of the present invention and the fault zone locating system using this method will be described in detail below with reference to FIGS. 2. Configuration of Failure Section Locating System This failure section locating system is, as shown in FIG. 1, a steel tower 4a, 4 for connecting a first transmission line 31 and a second transmission line 32.
.. provided in b, 4c ..., And a master station 2 connected to these slave stations 1a, 1b, 1c.

The slave station 1 has a current sensor 1 as shown in FIG.
1, 12 and the addition value output unit 13. Each of the current sensors 11 and 12 is a magnetic sensor and is provided so as to be able to detect the magnetism generated by the current flowing through the first power transmission line 31 and the second power transmission line 32. Also,
The current sensors 11 and 12 are the transmission lines 12 and 1 of the other line.
The direction is adjusted so that it does not react to the magnetism generated from No. 1, and a magnetic shield is applied. The current sensor 1
Nos. 1 and 12 are provided so as to detect magnetism generated from two phases of one line. This is because a sufficient output can be obtained even if the detection of a plurality of phases is performed at the same time, and the failure can be determined.

The added value output unit 13 includes current sensors 11, 1
It is an electronic circuit that amplifies the output of No. 2 to a required size, adds the two to generate an added value, and outputs the generated added value to the master station 2. Further, the slave station 1 and the master station 2 are connected by any communication means. This communication means includes a dedicated radio device using a PHS telephone, a wireless output means for transmitting using a wireless device such as a mobile phone and a wireless LAN device, and a wired output means for appropriately amplifying and outputting via a wire or an optical fiber. It can be a means. The power source of the slave station 1 is not particularly limited and can be arbitrarily selected. As an example of this, a battery that is charged by a solar cell or a wind power generator,
Inductive power from a transmission line can be used. Master station 2
Is a computer that stores an electronic circuit that receives the added value transmitted from each slave station 1 and locates a faulty section by the faulty zone locating method, or a program that performs the locating.

3. Method and Effect of Use of Fault Section Locating System This fault section locating system is used for each slave station 1a, 1b, 1c ...
Detects the current values of the power transmission lines 31 and 32 by the current sensors 11a ... 12a, adds the added values by the added value output unit 13, and transmits the added values to the master station 2. The master station 2
It is determined whether each slave station 1 is an operating point or a non-operating point. If there is a non-operation point, the operation point and the non-operation point found by searching the upstream operation point are output as a failure section.

According to such a fault section locating system, the fault point can be located only by the current sensor, and the voltage sensor, the current direction discriminating circuit, etc. are unnecessary, so that an inexpensive locating device can be manufactured. it can. Further, even if the fault current waveform is deformed by a harmonic component such as noise generated at a fault location or the like, the fault section can be easily located.

4. Slave station provided with current sensor for each phase Slave station 1 of the main fault section location system is not limited to one current sensor provided per line as shown in FIG. You can For example, as shown in FIG. 8, the current sensors 11A, 11 are provided on the respective phases 31A, 31B, 31C of the first power transmission line 31.
B and 11C are provided, and each phase 32A, 32 of the second power transmission line 32 is provided.
B and 32C can be provided with current sensors 12A, 12B and 12C.

As described above, when a plurality of current sensors are provided for one line, both transmission lines 31, 3 corresponding to the same phase are provided.
The additional value is calculated for the current sensors 11 and 12 of No. 2, and the failure is determined. Further, by providing a plurality of current sensors for each line, it is possible to determine which phase has failed.

Further, as shown in FIG. 9, two current sensors 11D, 11E (12D, 12E) can be provided so that one current sensor detects the currents of the transmission lines for two phases. In addition, these two current sensors 11D and 11E
(12D, 12E) are provided so as to detect the phase B in an overlapping manner. With such an arrangement, when the failure is detected only by the current sensor 11D (12D), the phase A, when the failure is detected only by the current sensor 11E (12E), the phase C, the current sensor 11D (12D) And current sensor 11
When a failure is detected at E (12E), it can be determined that the phase is B phase or all phases, and a short circuit for each phase can be determined with the same fineness as when a current sensor is provided for each phase. .

It should be noted that the present invention is not limited to the above-mentioned embodiment, but various modifications may be made within the scope of the present invention according to the purpose and application. That is, in the present transmission line sensor, the current sensor and the additional value output unit forming the slave station are separate, but the additional value output unit can be integrated with any of the current sensors. In such a slave station, the number of wires and the number of installation works are reduced, and the workability can be further improved. Further, the additional value output unit may be divided and provided in each current sensor. Further, in the present fault segment location system, the master station 2 and each slave station 1 are separate bodies, but the master station 2 may be provided in any one of the slave stations. In addition, even in a line where three or more transmission lines are provided in one transmission line tower, select any two lines that perform power transmission in parallel, and perform the fault segment location method and the fault segment location system. By applying it, it is possible to specify the fault section including the short-circuit fault point.

[Brief description of drawings]

FIG. 1 is a schematic diagram for explaining the configuration of the present fault segment location system.

FIG. 2 is a schematic diagram for explaining a two-line power transmission line in a normal state.

FIG. 3 is a graph for explaining an example of an output and an added value of a current sensor at a normal time.

FIG. 4 is a schematic diagram for explaining a two-line power transmission line in the event of a one-line short circuit accident.

FIG. 5 is a graph for explaining an example of the output and the added value of the current sensor at the time of a one-circuit short circuit accident.

[Fig. 6] Fig. 6 is a schematic diagram for explaining a two-line power transmission line in the event of a one-line short circuit accident.

FIG. 7 is a schematic diagram for explaining an example of a state in which a slave station is provided on a steel tower.

FIG. 8 is a schematic diagram for explaining an example of a state in which a current sensor is provided for each phase of the power transmission line.

FIG. 9 is a schematic diagram for explaining an example of a state in which two current sensors are provided so that one phase of a power transmission line overlaps.

[Explanation of symbols]

1; slave station, 11; first current sensor, 12; second current sensor, 13; additional value output unit, 2; parent station, 31; first power transmission line, 32; second power transmission line, 4; steel tower, 51 Upstream, 52;
Downstream, 53, 54; parallel connection point, 61, 62; short-circuit current, P; failure point.

Claims (4)

[Claims] 1. At least one current sensor is provided for each line in a two-line power transmission line that transmits power in parallel, and when at least one output value of the current sensor detects an overcurrent exceeding a predetermined value, It is determined as a failure section between a dead point where the added value of the output values in each of the lines is within a predetermined range or less and an operation point upstream of the dead point and where the added value exceeds the predetermined range. A fault segment location method characterized by 2. The fault section locating method according to claim 1, wherein the locating is performed when an overcurrent in which the output values of the current sensors of the same phase on both the lines exceed a predetermined value is detected. 3. The fault segment locating method according to claim 1, wherein the predetermined value is a ratio to the output of the current sensor at the same point. 4. In a two-line transmission line that transmits power in parallel, at least one current sensor is provided for each line, and an added value that outputs at least an added value obtained by adding the outputs of the current sensors of each line. The system includes: two or more slave stations including an output unit; and a master station including a failure section locating unit that receives the added value output from the slave stations and locates the failure section, and the failure section locating unit includes An overcurrent in which at least one output value of the current sensor exceeds a predetermined value is detected, and the slave station at an inoperative point where the added value of the output values falls below a predetermined range; and an upstream side from the operating point. A fault segment locating system characterized by determining a fault segment between the slave station at an operating point where the added value exceeds a predetermined range.