JP2010164514A - Fault point locator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fault point locator locating a fault point accurately by a grounding impedance operation system upon a one-line grounding fault in a multi-terminal parallel two-line power transmission line. <P>SOLUTION: A fault point locating circuit 20 in a first power source end fault locator 10<SB>1</SB>includes: a first logic product circuit 23<SB>1</SB>for taking a logic product of an output signal of a first inverter circuit 24<SB>1</SB>for inverting polarity of an output signal of a self-circuit Z comparator circuit 21 and an output signal of a both-circuit Z comparator circuit 22; an extension circuit 25 for extending a time base of an output signal of the first logic product circuit 23<SB>1</SB>; a second logic product circuit 23<SB>2</SB>for taking a logic product of the output signal of the first logic product circuit 23<SB>1</SB>and an output signal of the extension circuit 25; and branch load compensation prohibition/execution instruction means 27, 28 for instructing prohibition or execution of branch load compensation corresponding to polarity of an output signal of the second logic product circuit 23<SB>2</SB>, relative to a locating circuit 29 for performing distance operation to the fault point by the grounding impedance operation system. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a failure point locating device, and more particularly, to a failure point locating device suitable for locating an accident point at the time of a one-line ground fault in a multi-terminal balanced two-line transmission line of a high resistance grounding system.

  In general, the ground fault impedance calculation method is used to determine the fault point at the time of a one-line transmission line ground fault, and the fault point is determined based on the impedance up to the fault point measured using the line voltage and line current. Seeking distance.

  However, when locating the fault point using the ground fault impedance calculation method in the case of a one-line ground fault in a multi-terminal balanced two-line transmission line with a high resistance grounding system, the branch load current is added to the fault current. In some cases, the impedance to the accident point measured using the current becomes smaller than the actual impedance, and the accident point cannot be accurately determined.

In the failure point locating device disclosed in Patent Document 1 below, the first and second auxiliary timers driven by the operation of the ground fault direction relay built in the failure point locating device are installed, and the first The auxiliary timer is set to the series trip time limit by the existing line selection relay, the second auxiliary timer is set to the trip time limit by the ground fault direction relay, and the circuit breaker trip at the installation end of the fault locator is first and A determination means for determining which settling time of the second auxiliary timer was performed is provided, and after determining and executing whether or not the line branch load compensation is performed by the determination means, the failure point by the ground fault impedance calculation method is determined. The distance to the failure point is determined by the orientation means.
Japanese Patent No. 3376632

  As described above, it is necessary to remove the influence of the branch load current in order to accurately determine the fault point by the ground fault impedance calculation method at the time of the one-line ground fault in the multi-terminal balanced two-line transmission line.

  In the failure point locating device disclosed in Patent Document 1, it is determined whether the circuit breaker trip at the installation end of the failure point locating device has been performed within the settling time of the first or second auxiliary timer. Since the influence of the branch load current is removed using the means, there is no problem if the number of terminals of the balanced two lines is the same. However, when the number of terminals is changed, it may be necessary to perform settling again. .

  An object of the present invention is to provide a failure point locating device capable of accurately locating an accident point by a ground fault impedance calculation method at the time of a one-line ground fault in a multi-terminal balanced two-line transmission line.

The fault location apparatus of the present invention branches from its own line (1L) and other line (2L) laid between the power source end side bus and the opposite end side opposite end bus and the own line and other line. A failure point locating device (10 ₁ ) installed on the power supply end side of the balanced two-line transmission line having the divided self-branch line (3L) and the other branch line (4L), When a ground fault occurs on a line, branch load compensation is performed on the current line current (I ₁ ) flowing from the power supply end of the line toward the point of failure, and the distance to the point of failure is determined by the ground fault impedance calculation method. An accident point locating circuit (20; 60) for performing an operation, and the accident point locating circuit is connected to the opposite end side of the own line and the load end of the own branch line based on changes in the own line impedance and both line impedances. Other terminals installed on the side When vessel (4 _3, 4 ₅₎ detects that it has been cut off, to make a distance calculation to the fault point by ground fault impedance calculation method based solely on the self-line line current without the branch load compensation Features.
Here, when the fault line locating circuit (20; 60) divides the bus voltage (Va) by the own line current and the own line impedance (Z ₁ ) is equal to or less than the first threshold (Th _1a ). An own line impedance comparison circuit (21; 61) for outputting an output signal, and dividing the bus voltage by the sum of the own line current and the other line current (I ₂ ) flowing through the power supply end of the other line. When the calculated both line impedance (Z _a ) is equal to or less than the second threshold (Th _2a ), the both line impedance comparison circuit (22; 62) that outputs an output signal and the polarity of the output signal of the own line impedance comparison circuit are inverting inverter circuit; and (24 ₁ 64), said first aND circuit taking the logical product of the output signals of both line impedance comparator circuit and the output signal of the inverter circuit (23 _1; 63 ₁ A stretching circuit (25; 65) for stretching the time axis of the output signal of the first AND circuit by a time (DL), the output signal of the first AND circuit and the stretching A second logical product circuit (23 ₂ ; 63 ₂ ) that performs a logical product with the output signal of the analog circuit, an orientation circuit (29; 69) that performs a distance calculation to the fault point by a ground fault impedance calculation method, Branch load compensation prohibition / execution instructing means (27, 28; 67, 68) for instructing the orientation circuit to prohibit or execute the branch load compensation in accordance with the polarity of the output signal of the second AND circuit. You may prepare.
The extension time includes a relay judgment time (T _RY ) of a ground fault direction relay device built in the fault location device, and a circuit breaker cutoff time of the own circuit breaker installed at the power supply terminal of the own line It may be longer than the total time of (T _CB ).
Said fault point orientation circuit, the other line of the next line breaker installed in the power source terminal side (4 ₂₎ provided that the is not interrupted, the other based on a change of the own line impedance and both line impedance When it is detected that the terminal breaker has been cut off, the distance to the fault point may be calculated by a ground fault impedance calculation method based only on the own line current without performing the branch load compensation.
The fault location circuit (60) further includes an orientation range determination circuit (70) for determining an orientation range of the fault location device based on an own line impedance calculated by dividing the bus voltage by the own line current. And the branch load compensation prohibition / execution instructing means (67, 68) determines that the orientation range determination circuit determines that the orientation range of the fault location device is a one-stage orientation range. The branch load compensation prohibition may be instructed.
The one-step location range of the location range of the failure point location device is determined from the power supply end of the own line to the own branch of the unbalanced branch line (5L) laid on the power supply end side of the own line from the own branch line. It may be a range up to the line side.
Another failure point locating device (10 ₂ ; 50 ₂ ) installed on the power supply end side of the other line may have the same configuration as that of the failure point locating device and may be integrally formed.
Also, the fault location apparatus of the present invention includes the own line (1L) and the other line (2L) laid between the bus on the power supply side and the opposite end bus on the opposite end, the own line and the other line. A fault location device (30 ₁ ; 80 ₁ ) installed on the opposite end side of the balanced two-line transmission line having the own branch line (3L) and the other branch line (4L) branched from When a ground fault occurs in the own line, branch load compensation is performed on the own line current (I ₃ ) flowing from the opposite end of the own line toward the fault point, and a ground fault impedance calculation method is performed. An accident point locating circuit (40; 40a; 90) for calculating a distance to the accident point is provided, and the accident point locating circuit is connected to the power supply end side of the own line and the own branch line based on a change in own line impedance. Shut off other terminals installed on the load end side (4 _1, 4 ₅₎ detects that it has been cut off, wherein said performing the distance calculation to the fault point by ground fault impedance calculation method based solely on its own line line current without the branch load compensation And
Here, the fault point locating circuit (40) is self-line impedance opposite ends bus voltage (Vb) was calculated by dividing by the self line line current (Z ₃₎ When is below a first threshold value (Th _1b) A self-line impedance comparison circuit (41) that outputs an output signal, and the opposite-end bus voltage is divided by the sum of the own-line current and the other-line current (I ₄ ) that flows on the opposite-end side of the other line. When the calculated both line impedance (Z _b ) is equal to or less than the second threshold (Th _2b ), the both line impedance comparison circuit (42) that outputs an output signal and the polarity of the output signal of the both line impedance comparison circuit are inverted. an inverter circuit (44 _1), the aND circuit taking the logical product of the output-signal of the line impedance comparison circuit and an output signal of the inverter circuit (43 _1), the ground fault impedance calculation An orientation circuit (49) that calculates the distance to the accident point using an equation, and a branch load compensation prohibition that instructs the orientation circuit to prohibit or execute the branch load compensation according to the polarity of the output signal of the AND circuit / Execution instruction means (47, 48).
When the own line impedance (Z ₃ ) calculated by the accident point locating circuit (40a) by dividing the opposite-end bus voltage (Vb) by the own line current is equal to or lower than the first threshold (Th _1b ), an output signal is output. The output self-line impedance comparison circuit (41), the inverter circuit (51) for inverting the polarity of the output signal of the self-line impedance comparison circuit, and the output signal of the ground fault overvoltage relay device installed on the opposite end bus (S _OVG ) or a first AND circuit (52) that takes a logical product of the output signal of the ground fault overcurrent relay device installed on the opposite end side of the own line and the output signal of the inverter circuit, An extension circuit (53) for extending the time axis of the output signal of the first AND circuit by an extension time (DL); an output signal of the own line impedance comparison circuit; and an output signal of the extension circuit; AND of The second logical product circuit (43 ₁ ), the orientation circuit (49) for calculating the distance to the fault point by the ground fault impedance calculation method, and the output signal of the second logical product circuit according to the polarity of the output signal. Branch load compensation prohibition / execution instructing means (47, 48) for instructing the orientation circuit to prohibit or execute the branch load compensation may be provided.
When the own line impedance (Z ₃ ) calculated by the accident point locating circuit (90) by dividing the opposite end bus voltage (Vb) by the own line current is equal to or lower than the first threshold (Th _1b ), an output signal is output. Both the self-line impedance comparison circuit (91) to be output and the opposite-end bus voltage divided by the sum of the own-line current and the other-line current (I ₄ ) flowing on the opposite-end side of the other line an inverter circuit for inverting the line impedance (Z _b) is a second threshold value (Th _2b) both line impedance comparator circuit for outputting an output signal falls below (92), the polarity of the output signal of the own line impedance comparator circuit ( 94), said first aND circuit taking the logical product of the output signals of both line impedance comparator circuit and the output signal of the inverter circuit (93 _1), the output of the aND circuit of said first And a second circuit that takes a logical product of the output signal of the own line impedance comparison circuit and the output signal of the extension circuit. An AND circuit (93 ₂ ), an orientation circuit (99) that calculates the distance to the fault point by the ground fault impedance calculation method, and the self-line impedance calculated by dividing the opposite-end bus voltage by the self-line current. Based on the orientation range determination circuit (100) for determining the orientation range of the failure location system based on the polarity of the output signal of the second AND circuit, the branch load compensation is prohibited for the orientation circuit. In addition, when the location range determination circuit determines that the location range of the fault location device is a one-step location range, the branch load compensation that instructs the location circuit to prohibit the branch load compensation is performed. Inhibition circuit (97) and may be provided.
The one-step location range of the location range of the fault location device is determined to be that of the unbalanced branch line (5L) that is laid from the opposite end of the own line to the opposite end side of the own line rather than the own branch line. It may be a range up to the line side.
It said another line other fault point locating system installed on the opposite end side of the (30 _2; 80 ₂₎ may be configured to have and integrally of the same structure as said failure point locating system.

The failure point locating device of the present invention has the following effects.
(1) When it is detected that the circuit breaker installed at the other terminal is cut off based on the change of the own line impedance and both line impedances or the change of the own line impedance, the fault point is determined without performing the branch load compensation. As a result, the fault point can be accurately determined by the ground fault impedance calculation method, and it is not necessary to redo the setting even when the number of terminals of the balanced two lines is changed.
(2) Since the accident point can be accurately pinpointed, the labor of the transmission line inspection work can be reduced, for example, the transmission line inspection range can be narrowed.

  For the above purpose, if it is detected that the circuit breaker installed at the other terminal is cut off based on the change of the own line impedance and both line impedances or the change of the own line impedance, the ground fault impedance calculation is performed without branching load compensation. It was realized by locating the accident point by the method.

Embodiments of the fault location apparatus of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the first and second power supply terminal fault point locating devices 10 ₁ and 10 ₂ , which are failure point locating devices according to the first embodiment of the present invention, are connected to the power sources of the own line 1L and the other line 2L. Installed on each end. Further, the first and second opposing end failure point locating devices 30 ₁ , 30 ₂ , which are failure point locating devices according to the first embodiment of the present invention, are connected to opposite ends (non-power supply ends) of the own line 1L and the other line 2L. ) Is installed on each side.
The own branch line 3L and the other branch line 4L are branched from the own line 1L and the other line 2L.

First power supply terminal fault point locating system 10 _1, the provided power terminal side of the bus voltage Va (the line voltage) and self line 1L inputted from the first transformer 2 ₁ provided to the bus 1 Based on the first line current I ₁ (line current) input from the current transformer 3 ₁ , the first impedance Z ₁ (Z ₁ = Va / I ₁ : own line impedance) of the own line 1L is calculated. Then, the fault point is determined based on the calculated first impedance Z ₁ .
The first power supply terminal fault point locating system 10 _1, the self-line impedance (first impedance Z ₁₎ and the third placed on opposite end of its own line 1L by a change in both the line impedance Z _a, which will be described later breaker 4 ₃ and upon detection of the interruption of the fifth circuit breaker 4 ₅ installed at the load end side of the self-branching line 3L of, Standardize fault point without branching load compensation.

Therefore, the first power supply terminal fault point locating system 10 ₁ is provided with a fault point locating circuit 20 shown in FIG.

As shown in FIG. 2, the fault location circuit 20 includes an own line impedance comparison circuit 21 (hereinafter referred to as “own line Z comparison circuit 21”) and a double line impedance comparison circuit 22 (hereinafter referred to as “both lines Z”). The _first to _fifth AND circuits 23 ₁ to 23 ₅ , the first and second inverter circuits 24 ₁ and 24 ₂ , the extension circuit 25, and the branch load A compensation prohibiting circuit 27, a branch load compensating circuit 28, and an orientation circuit 29 are provided.

The own line Z comparison circuit 21 calculates the first impedance Z ₁ (Z ₁ = Va / I ₁ ) by dividing the bus voltage Va by the first line current I ₁ , and then calculates the calculated first impedance Z _1. Is equal to or lower than the first threshold Th _1a (impedance from the power supply end to the center of the own line 1L), a high level output signal is output.
Both line Z comparator circuit 22, a bus voltage Va first line current I ₁ and a second line which is input from the second current transformer 3 ₁ installed on the power supply end of the other line 2L current I ₂ After calculating the divided by the sum both line impedance _{Z a (Z a = Va /} (I 1 + I 2)) and, when both line impedance Z _a calculated falls below a second threshold value Th _2a of the high level output Output a signal.
The first inverter circuit 24 ₁ inverts the polarity of the output signal of the own line Z comparison circuit 21.
The first logical product circuit 23 ₁ takes the logical product of the output signal of the _first inverter circuit 24 _{1 and} the output signal of the two-line Z comparison circuit 22.
The extending circuit 25 extends the time axis of the output signal of the _first AND circuit 23 ₁ and extends the time DL. Here, the spreading time DL, the first ground directional relay relay determination time T _RY and the first circuit breaker (not shown) incorporated in the first power supply terminal fault point locating system 10 ₁ 4 ₁ It is set to a value longer than the total time of the circuit breaker breaking time T _CB (DL> T _RY + T _CB ).
The second logical product circuit 23 ₂ takes a logical product of the output signal of the first logical product circuit 23 ₁ whose time axis is expanded by the extending circuit 25 and the output signal of the own-line Z comparison circuit 21.
The third AND circuit 23 ₃ is connected to the second contact signal S _C2 input from the second circuit breaker 4 ₂ installed on the power supply end side of the other line 2L and the output of the _second AND circuit 23 ₂ . Logical product with signal.
The second inverter circuit 24 _2, inverts the polarity of the third AND circuit 23 ₃ of the output signal of the.

The fourth AND circuit 23 _4, the first trip signals S ₁ and the third output from the first earth fault directional relay in a first breaker 4 ₁ installed on the power supply end of the self-line 1L The logical product with the output signal of the logical product circuit 23 ₃ is obtained.
The fifth logical product circuit 23 ₅ takes a logical product of the first trip signal S ₁ and the output signal of the _second inverter circuit 24 ₂ .
When a high level output signal is input from the _fourth AND circuit 234, the branch load compensation prohibiting circuit 27 outputs a branch load compensation prohibiting instruction signal for prohibiting the branch load compensation to the orientation circuit 29.
When a high level output signal is input from the _fifth AND circuit 235, the branch load compensation circuit 28 outputs a branch load compensation instruction signal for causing the orientation circuit 29 to perform branch load compensation.
When the branch load compensation prohibition instruction signal is input from the branch load compensation prohibition circuit 27, the orientation circuit 29 calculates the distance to the accident point (accident point determination by the ground fault impedance calculation method based on the first line current I _1. ) performed, the branch load compensation instruction signal is inputted from the branch load compensation circuit 28, the distance calculation to the fault point by ground fault impedance calculation method based on the current obtained by subtracting the branch load current from a first line current I ₁ (Accident point location).

Second _second power source terminal fault point locating system 10 is configured similarly to the first power supply terminal fault point locating system 10 ₁ described above.

The first opposing end fault point locating system 30 ₁ is provided on the opposite end side of the opposite ends bus voltage Vb (the line voltage) and self line 1L inputted from the second transformer 2 ₂ provided at opposite ends bus The third impedance Z ₃ (Z ₃ = Vb / I ₃ : own line impedance) of the own line 1L based on the third line current I ₃ (line current) input from the third current transformer 3 ₃ ) And the fault point is determined based on the calculated third impedance Z ₃ .
In addition, the first opposed terminal failure point locating device 30 ₁ includes first and fifth circuit breakers 4 ₁ and 4 ₅ due to changes in its own line impedance (third impedance Z ₃ ) and both line impedances Z _b described later. When the interruption is detected, the fault point is located without performing branch load compensation.

Therefore, the first opposing end fault point locating system 30 ₁ is provided with a fault point locating circuit 40 shown in FIG.

As shown in FIG. 3, the accident point locating circuit 40 includes an own line impedance comparison circuit 41 (hereinafter referred to as “own line Z comparison circuit 41”) and a both line impedance comparison circuit 42 (hereinafter referred to as “both lines Z”). A first comparison circuit 42 ”, _first to _fourth AND circuits 43 ₁ to 43 ₄ , first and second inverter circuits 44 ₁ and 44 ₂ , a branch load compensation prohibiting circuit 47, and a branch A load compensation circuit 48 and an orientation circuit 49 are provided.

The own line Z comparison circuit 41 calculates the third impedance Z ₃ (Z ₃ = Vb / I ₃ ) by dividing the opposite-end bus voltage Vb by the third line current I ₃ , and then calculates the calculated third impedance. When Z ₃ becomes equal to or less than the first threshold Th _1b (impedance from the opposite end of the own line 1L to the center), a high-level output signal is output.
Both lines Z comparison circuit 42 uses the fourth line current I inputted from the opposite line bus voltage Vb from the third line current I ₃ and the fourth current transformer 3 ₄ installed on the opposite end side of the other line 2L. _After dividing the sum of ₄ and the line impedance Z _b (Z _b = Vb / (I ₃ + I ₄ )), when the calculated line impedance Z _b falls below the second threshold Th _2b , the high level Output the output signal.
The first inverter circuit 44 ₁ inverts the polarity of the output signal of both the line Z comparison circuits 42.
First AND circuit 43 ₁ takes the logical product of the output signal and the first inverter circuit 44 ₁ of the output signal of the self channel Z comparator circuit 41.
Second AND circuit 43 ₂ takes the logical product of the fourth fourth contact signal S _C4 to the first AND circuit 43 ₁ of the output signal input from the breaker 4 _4.
The second inverter circuit 44 ₂ inverts the polarity of the output signal of the _second AND circuit 43 ₂ .

The third AND circuit 43 ₃ of the third trip signal S outputted from the third ground directional relay built in the first opposing end fault point locating system 30 ₁ to the third circuit breakers 4 _{3 3} is ANDed with the output signal of the _second AND circuit 43 ₂ .
The fourth logical product circuit 43 ₄ takes a logical product of the third trip signal S ₃ and the output signal of the _second inverter circuit 442.
When a high level output signal is input from the _third AND circuit 433, the branch load compensation prohibiting circuit 47 outputs a branch load compensation prohibiting instruction signal for prohibiting branch load compensation.
When a high level output signal is input from the _fourth AND circuit 434, the branch load compensation circuit 48 outputs a branch load compensation instruction signal for performing branch load compensation.
When the branch load compensation prohibition instruction signal is input from the branch load compensation prohibition circuit 47, the orientation circuit 49 calculates the distance to the accident point (accident point determination by the ground fault impedance calculation method based on the third line current I _3. ) performed, the branch load compensation instruction signal is inputted from the branch load compensation circuit 48, the distance calculation to the fault point due to grounding impedance computing method based on the current obtained by subtracting the branch load current from the third line current I ₃ (Accident point location).

The second opposing end failure point locating device 30 ₂ is configured in the same manner as the first opposing end failure point locating device 30 ₁ described above.

Next, a ground fault will be described first operation of the power supply end fault point locating system 10 ₁ in the case of generating the own line 1L.

First, a description will be given of a first operation of the power supply end fault point locating system 10 ₁ in the case of ground fault in the power supply end than the branch point to the own branch line 3L of the own line 1L occurs.
When a ground fault in such a fault point is generated, the first breaker 4 ₁ by the first line selection relay built in the first power supply terminal fault point locating system 10 ₁ is cut off instantly. In addition, since the first line current I ₁ flowing from the power source end of the own line 1L toward the accident point is only the fault current until the _first circuit breaker 41 is cut off from the occurrence of the ground fault, the branch load compensation is performed. Therefore, the location circuit 29 of the fault location circuit 20 (see FIG. 2) provided in the first power supply terminal failure location system 10 ₁ is used for ground fault impedance calculation based on the first line current I _1. Calculate the distance to the accident point (location of the accident point) according to the method.

Next, a description will be given of a first operation of the power supply end fault point locating system 10 ₁ in the case of earth fault at the opposite end side of the branch point of the own branch line 3L of the own line 1L occurs.
When a ground fault occurs at such an accident point, since the impedance viewed from the power supply end of the own line 1L (that is, the first impedance Z ₁ ) is larger than the first threshold Th _1a , Since the output signal of the own line Z comparison circuit 21 of the orientation circuit 20 remains low level, the output signal of the second AND circuit 23 ₂ remains low level. As a result, since the output signal of the _third AND circuit 23 ₃ remains at the low level, the low-level output signal of the _third AND circuit 23 ₃ is input to the _fourth AND circuit 23 ₄ . The high-level output signal of the second inverter circuit 24 ₂ is input to the AND circuit 23 ₅ .
Further, since both line impedances (that is, both line impedances Z _a ) viewed from the power supply terminal of the own line 1L are equal to or less than the second threshold Th _2a , the output signal of both line Z comparison circuits 22 changes from low level to high level. Become. As a result, in the first AND circuit 23 ₁ , the output signal of the own line Z comparison circuit 21 whose polarity is inverted to the high level by the first inverter circuit 24 ₁ and the high level output of both the line Z comparison circuits 22 are output. Since the signal is input, the output signal of the _first AND circuit 23 ₁ is changed from the low level to the high level. The high-level output signal of the _first AND circuit 23 ₁ is extended by the extending circuit 25 for the time DL by extending the time axis.

Then, at the same time when the third breaker 4 ₃ placed on the opposite end side of the own line 1L is blocked by the third line selection relay built in the first opposing end fault point locating system 30 _1, the self when the fifth breaker 4 ₅ arranged at the load end side of the branch line 3L is cut off by the ground fault protective relay device for the mobile branch line 3L (not shown), the fault current of the own line 1L Since the current flows only from the power supply end toward the accident point (that is, the first line current I ₁ becomes large), the impedance viewed from the power supply end of the own line 1L (that is, the first impedance Z ₁ ) is the first. since falls below threshold Th _1a, the output-signal of the line Z comparator circuit 21 is changed from the low level to the high level. As a result, since the output signal of the extension circuit 25 remains at the high level, the output signal of the second AND circuit 23 ₂ changes from the low level to the high level.
At this time, if the second contact signal S _C2 is at the high level (indicating that the _second circuit breaker 42 is not cut off), the output signal of the _third AND circuit 23 ₃ changes from the low level to the high level. Become a level. As a result, the high-level output signal of the _third AND circuit 23 ₃ is input to the fourth AND circuit 23 _4, and the low level of the second inverter circuit 24 ₂ is input to the fifth AND circuit 23 _5. Output signal is input.

Thereafter, when the first trip signals S ₁ of a high level from a first earth fault direction relay device incorporated in the first power supply terminal fault point locating system 10 ₁ is outputted, the fourth AND circuit 23 _Since the output signal ₄ changes from low level to high level, the branch load compensation prohibition instruction signal is output from the branch load compensation prohibition circuit 27 to the orientation circuit 29. As a result, the orientation circuit 29 calculates the distance to the accident point by the ground fault impedance calculation method based on the first line current I ₁ . At this time, since the third and fifth circuit breakers 4 ₃ and 4 ₅ are simultaneously interrupted before the _first circuit breaker 4 ₁ , the first ground fault direction relay device causes the high level first Until the trip signal S ₁ is output (that is, until the first circuit breaker 4 ₁ is cut off), the first line current I ₁ flowing to the power supply terminal of the own line 1L is only a fault current. Therefore, since it is not necessary to perform branch load compensation, the fault point is accurately determined even when the distance to the fault point is calculated by the ground fault impedance calculation method based on the first line current I ₁ as described above. be able to.

On the other hand, when the third breaker 4 ₃ after a ground fault occurs is interrupted prior to the breaker 4 ₅ The fifth fault current flows toward the fault point from the power source terminal of the own line 1L current And the current flowing from the power supply end of the other line 2L to the fault point by bypassing the other branch line 4L and the own branch line 3L, the impedance viewed from the power supply end of the own line 1L (that is, the first impedance) Since Z ₁ ) remains larger than the first threshold Th _1a , the output signal of the own-line Z comparison circuit 21 remains at a low level. As a result, the output signal of the _second AND circuit 23 ₂ also remains at a low level.
Therefore, in this case, since the output signal of the _third AND circuit 23 ₃ remains at low level, the fourth AND circuit 23 ₄ receives the low level output signal of the _third AND circuit 23 _3. The high-level output signal of the second inverter circuit 24 ₂ is input to the _fifth AND circuit 23 ₅ .

Thereafter, when the high-level first trip signal S ₁ is output from the first ground fault direction relay device, the output signal of the _fifth AND circuit 235 changes from the low level to the high level. A branch load compensation instruction signal is output from the compensation circuit 28 to the orientation circuit 29. As a result, the orientation circuit 29 calculates the distance to the accident point by the ground fault impedance calculation method based on the current obtained by subtracting the branch load current from the first line current I ₁ . Thereby, the accident point can be accurately determined.

Next, a ground fault will be described first operation opposing end fault point locating system 30 ₁ in the case of generating the own line 1L.

First, a description will be given of a first operation of the opposite end fault point locating system 30 ₁ in the case where the own branch line ground fault at the opposite end side of the branch point to 3L of its own line 1L occurs.
When a ground fault occurs in such a fault point, the third circuit breakers 4 ₃ by the third line selection relay built in the first opposing end fault point locating system 30 ₁ is cut off instantly.
Further, since the third line current I ₃ flowing through the opposite end of the own line 1L is only a fault current until the _third circuit breaker 4 ₃ is interrupted from the occurrence of the ground fault, there is no need to perform branch load compensation. The fault location circuit 40 (see FIG. 3) of the fault point location circuit 40 (see FIG. 3) provided in the first opposite-end fault location system 30 ₁ is connected to the fault point by the ground fault impedance calculation method based on the third line current I ₃ . Perform distance calculation (accident point location).

Next, a description will be given of a first operation of the opposite end fault point locating system 30 ₁ in the case where the own branch line ground fault in the power supply end than the branch point to 3L of its own line 1L occurs.
When a ground fault occurs at such an accident point, the impedance (that is, the third impedance Z ₃ ) viewed from the opposite end of the own line 1L after the ground fault occurs is higher than the first threshold Th _1b. since the self-line output signal of the Z comparator circuit 41 larger remains at a low level, the first output signal of the aND circuit 43 ₁ remains at the low level. As a result, since the output signal of the _second AND circuit 43 ₂ remains at the low level, the low level output signal of the _second AND circuit 43 ₂ is input to the _third AND circuit 43 _3, and the aND circuit 43 ₄ 4 output signal of the second inverter circuit 44 ₂ of a high level is input.

Then, at the same time when the first breaker 4 ₁ installed on the power supply end of the self-line 1L is blocked by the first line selection relay built in the first power-up fault point locating system 10 _1, the self when the fifth breaker 4 ₅ arranged at the load end side of the branch line 3L is cut off by the ground fault protective relay device for the mobile branch line 3L is the fault current accident from the opposite end of its own line 1L Since the current flows only toward the point (that is, the third line current I ₃ becomes large), the impedance viewed from the opposite end of the own line 1L (that is, the third impedance Z ₃ ) is the first threshold Th _1b. Therefore, the output signal of the own line Z comparison circuit 41 changes from the low level to the high level. Further, since both line impedances (that is, both line impedances Z _b ) viewed from the opposite end of the own line 1L are larger than the second threshold Th _2b , the output signals of both line Z comparison circuits 42 remain at low level. is there. As a result, the first AND circuit 43 ₁ has a high-level output signal from the own-line Z comparison circuit 41 and an output signal from the two-line Z comparison circuit 42 that has been changed from the low level to the high level by the first inverter circuit 44 ₁ . Are input, the output signal of the _first AND circuit 431 changes from the low level to the high level.
At this time, if the fourth contact signal S _C4 is at the high level (indicating that the _fourth circuit breaker 44 is not cut off), the output signal of the _second AND circuit 43 ₂ is changed from the low level to the high level. Become a level. As a result, the high-level output signal of the _second AND circuit 43 ₂ is input to the third AND circuit 43 _3, and the low level of the second inverter circuit 44 ₂ is input to the fourth AND circuit 43 _4. Output signal is input.

Thereafter, the first third of the third ground direction relay device which is built in the opposite end fault point locating system 30 ₁ of high level trip signal S ₃ is output, the third AND circuit 43 _Since the output signal ₃ changes from the low level to the high level, the branch load compensation prohibition instruction signal is output from the branch load compensation prohibition circuit 47 to the orientation circuit 49. As a result, the orientation circuit 49 calculates the distance to the accident point by the ground fault impedance calculation method based on the third line current I ₃ . At this time, since the first and fifth circuit breakers 4 ₁ , 4 ₅ are simultaneously disconnected before the _third circuit breaker 4 ₃ , the third ground fault direction relay device has a high level of the third circuit breaker. Until the trip signal S ₃ is output (that is, until the third circuit breaker 4 ₃ is cut off), the third line current I ₃ flowing through the opposite end of the own line 1L is only a fault current. Therefore, since it is not necessary to perform branch load compensation, the fault point is accurately determined even when the distance to the fault point is calculated by the ground fault impedance calculation method based on the third line current I ₃ as described above. be able to.

On the other hand, when the first breaker 4 ₁ after earth fault occurred is interrupted prior to the breaker 4 ₅ The fifth fault current flows toward the fault point from the opposite end of its own line 1L current And the current flowing from the opposite end of the other line 2L to the fault point by bypassing the other branch line 4L and the own branch line 3L, the impedance viewed from the opposite end of the own line 1L (that is, the third impedance) Since Z ₃ ) remains larger than the first threshold Th _1b , the output signal of the own line Z comparison circuit 41 remains at the low level. As a result, the output signal of the _first AND circuit 431 remains at the low level.
Therefore, in this case, since the second AND circuit 43 _{and second} output signals is kept at a low level, the third AND circuit 43 ₃ and the second AND circuit 43 ₂ at the low level of the output signal is input, the fourth aND circuit 43 ₄ of the output signal of the second inverter circuit 44 ₂ of a high level is input.

Thereafter, when the high level third trip signal S ₃ is output from the third ground fault direction relay device, the output signal of the _fourth AND circuit 434 is changed from the low level to the high level. A branch load compensation instruction signal is output from the compensation circuit 48 to the orientation circuit 49. As a result, the orientation circuit 49 calculates the distance to the accident point by the ground fault impedance calculation method based on the current obtained by subtracting the branch load current from the third line current I ₃ . Thereby, the accident point can be accurately determined.

The first opposing end fault point locating system 30 _1, instead of the fault point locating circuit 40 shown in FIG. 3, may include a fault point locating circuit 40a shown in FIG.
As shown in FIG. 4, the accident point locating circuit 40 a has an inverter circuit 51 that inverts the polarity of the output signal of the own line Z comparison circuit 41, and the output signal of the inverter circuit 51, An AND circuit 52 that _performs an AND operation with an OVG output signal S _OVG that is input from a ground fault overvoltage relay device (not shown) installed on the opposite end bus, and a time axis of the output signal of the AND circuit 52 is drawn. 3 is different from the accident point location 40 shown in FIG. 3 in that it includes an extension circuit 53 that extends only the extension time DL.

  When a ground fault occurs near the opposite end of the own line 1L, the accident point locating circuit 40a operates in the same manner as the accident point locating circuit 40 described above.

When a ground fault occurs near the power supply terminal of the own line 1L and the magnitude of the opposite-end zero-phase voltage V _0b exceeds the set value, the high-level OVG output signal S _OVG is output from the ground fault overvoltage relay. It is input to the orientation circuit 40a. Further, as described above, since the impedance viewed from the opposite end of the own line 1L (that is, the third impedance Z ₃ ) is larger than the first threshold Th _1b when a ground fault occurs, the own line Z comparison circuit 41 The output signal remains low. The output signal of the own line Z comparison circuit 41 is inverted in polarity by the inverter circuit 51 and changes from the low level to the high level. As a result, the output signal of the AND circuit 52 changes from the low level to the high level.
The high-level output signal of the AND circuit 52 is extended by the extending circuit 53 by the time DL by extending the time axis.

Thereafter, when the first and fifth circuit breakers 4 ₁ , 4 ₅ are simultaneously interrupted as described above, the impedance (that is, the third impedance Z ₃ ) viewed from the opposite end of the own line 1L is the first. since the threshold below Th _1b, the output-signal of the line Z comparator circuit 41 becomes a high level from a low level. As a result, since the high-level output signal of the own-line Z comparison circuit 41 and the high-level output signal of the extension circuit 53 are input to the logical product circuit 52, the output signal of the logical product circuit 52 starts from the low level. Become high level.
At this time, if the fourth contact signal S _C4 is at the high level (indicating that the _fourth circuit breaker 44 is not cut off), the output signal of the _second AND circuit 43 ₂ is changed from the low level to the high level. Become a level. As a result, the high-level output signal of the _second AND circuit 43 ₂ is input to the third AND circuit 43 _3, and the low level of the second inverter circuit 44 ₂ is input to the fourth AND circuit 43 _4. Output signal is input.

Thereafter, when the third trip signal S ₃ of the high level from the third ground direction relay device is output, the third output signal of the AND circuit 43 ₃ is at a high level from a low level, the branch load A branch load compensation prohibition instruction signal is output from the compensation prohibition circuit 47 to the orientation circuit 49. As a result, the orientation circuit 49 calculates the distance to the accident point by the ground fault impedance calculation method based on the third line current I ₃ .

On the other hand, when the first breaker 4 ₁ has been interrupted prior to breaker 4 ₅ fifth after ground fault occurs, the impedance as viewed from the opposite end of its own line 1L (i.e., the third impedance Since Z ₃ ) remains larger than the first threshold Th _1b , the output signal of the own line Z comparison circuit 41 remains at the low level. As a result, the output signal of the _first AND circuit 431 remains at the low level.
Therefore, in this case, since the second AND circuit 43 _{and second} output signals is kept at a low level, the third AND circuit 43 ₃ and the second AND circuit 43 ₂ at the low level of the output signal is input, the fourth aND circuit 43 ₄ of the output signal of the second inverter circuit 44 ₂ of a high level is input.

Thereafter, when the high level third trip signal S ₃ is output from the third ground fault direction relay device, the output signal of the _fourth AND circuit 434 is changed from the low level to the high level. A branch load compensation instruction signal is output from the compensation circuit 48 to the orientation circuit 49. As a result, the orientation circuit 49 calculates the distance to the accident point by the ground fault impedance calculation method based on the current obtained by subtracting the branch load current from the third line current I ₃ .

The OVG output signal S _OVG of the ground fault overvoltage relay installed on the opposite end bus is inputted to the AND circuit 52, but the output of the ground fault overcurrent relay installed on the opposite end side of the own line 1L. A signal may be input to the AND circuit 52.

Next, the first and second power supply terminal failure point locating devices 50 ₁ and 50 ₂ which are failure point locating devices according to the second embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 5, the first and second power supply terminal failure point locating devices 50 ₁ and 50 _{2 according} to the present embodiment have their own unbalanced branch line 5L laid on the power supply end side with respect to the own branch line 3L. It is installed on the power supply end side of the line 1L.

The first power supply terminal failure point locating device 50 ₁ locates the accident point as follows.
(1) When the first ground fault direction relay device (not shown) built in the first power supply terminal fault location device 50 ₁ operates, the branch load compensation of the own branch line 3L and the unbalanced branch line 5L is performed. Do.
(2) When the first circuit breaker 4 ₁ is interrupted in advance due to a ground fault, the first location range of the first power supply terminal fault location device 50 ₁ (self-branching from the power supply end of the own line 1L) The branch load compensation is not performed when the ground fault is within the range of the line 3L up to the own line 1L side, and the branch load compensation is performed when the ground fault is outside the first orientation range.
(3) upon detection of the cutoff of the third breaker 4 ₃ by a change in its own line impedance and both line impedance does not perform the branch load compensation.
(4) The orientation calculation is performed until the orientation error is converged, and all the results of the orientation calculation including the progress are displayed outside.

Therefore, the first power supply terminal failure point locating device 50 ₁ includes an accident point locating circuit 60 shown in FIG.

As shown in FIG. 6, the fault location circuit 60 includes an own line impedance comparison circuit 61 (hereinafter referred to as “own line Z comparison circuit 61”) and a double line impedance comparison circuit 62 (hereinafter referred to as “both lines Z”). The first to sixth AND circuits 63 _{1 to} 63 ₆ , the inverter circuit 64, the extension circuit 65, the branch load compensation prohibiting circuit 67, and the branch load compensation circuit. 68, an orientation circuit 69, an orientation range determination circuit 70, and an OR circuit 71.

The own line Z comparison circuit 61, like the own line Z comparison circuit 21 shown in FIG. 2, divides the bus voltage Va by the first line current I ₁ to obtain a first impedance Z ₁ (Z ₁ = Va / I After calculating ₁ ), a high-level output signal is output when the calculated first impedance Z ₁ is equal to or lower than the first threshold Th _1a (impedance from the power supply end of the own line 1L to the center).
Similarly to the two-line Z comparison circuit 22 shown in FIG. 2, the two-line Z comparison circuit 62 divides the bus voltage Va by the sum of the first and second line currents I ₁ and I ₂ , thereby generating the both-line impedance Z _a. After calculating (Z _a = Va / (I ₁ + I ₂ )), _a high-level output signal is output when the calculated both-line impedance Z _a becomes equal to or less than the second threshold Th _2a .
The inverter circuit 64 inverts the polarity of the output signal of the own line Z comparison circuit 61 in the same manner as the first inverter circuit 24 ₁ shown in FIG.
The first logical product circuit 63 ₁ takes the logical product of the output signal of the inverter circuit 64 and the output signal of the both-line Z comparison circuit 62 in the same manner as the first logical product circuit 23 ₁ shown in FIG.
Similar to the extending circuit 25 shown in FIG. 2, the extending circuit 65 extends the time axis of the output signal of the _first AND circuit 23 ₁ and extends it by the time DL. Here, the spreading time DL, the first circuit breaker interrupting the relay determination time ground fault directional relay T _RY and the first breaker 4 _of built in the first power supply terminal fault point locating system 50 ₁ It is set to a value longer than the total time of time T _CB (DL> T _RY + T _CB ).
Similarly to the _second AND circuit 23 ₂ shown in FIG. 2, the _second AND circuit 63 ₂ outputs an output signal of the _first AND circuit 63 ₁ whose time axis is expanded by the extending circuit 65. And the output signal of the own-line Z comparison circuit 61.
Similarly to the _third AND circuit 23 ₃ shown in FIG. 2, the _third AND circuit 63 ₃ is connected to the second contact signal S _C2 input from the second circuit breaker 4 ₂ and the second logic. The logical product with the output signal of the product circuit 63 ₂ is taken.

The orientation range determining circuit 70 calculates the first impedance Z ₁ (Z ₁ = Va / I ₁ ) by dividing the bus voltage Va by the first line current I ₁ , and then calculates the calculated first impedance Z ₁ . Based on this, the orientation range of the first power-source accident point location device 50 ₁ is determined.
That is, the orientation range determination circuit 70 determines that the calculated first impedance Z ₁ is the maximum impedance (hereinafter referred to as “first maximum impedance Z”) of the one-stage orientation range A1 of the first power source ground fault distance relay device 10 _{1. 1max} ”)) If it is equal to or less than this, it is determined that“ the location range of the first power supply end _fault location device 50 ₁ is the one-stage location range A1 ”, and the first and second judgments at the high level. Result output signals VD ₁ and VD ₂ are output. In addition, the orientation range determination circuit 70 has the calculated first impedance Z ₁ larger than the first maximum impedance Z _{1max and} the maximum impedance (hereinafter referred to as the maximum impedance of the two-stage orientation range A2 of the first power supply end _fault location device 50 _1. , _{Referred to as} “second maximum impedance Z _2max ”), it is determined that “the orientation range of the first power supply end _fault location device 50 ₁ is the two-stage orientation range A2” and the high level. The second determination result output signal VD ₂ is output.

The fourth logical product circuit 63 ₁ takes the logical product of the first and second determination result output signals VD ₁ and VD ₂ input from the orientation range determination circuit 70.
The fifth AND circuit 63 ₂ takes the logical product of the FD relay output signal S _FD and the first AND circuit 63 ₁ of the output signal from the relay device for fail-safe.
The sixth logical product circuit 63 ₆ takes the logical product of the second determination result output signal VD ₂ input from the orientation range determination circuit 70 and the FD relay output signal _SFD .
The logical sum circuit 71 takes a logical sum of the first trip signal S ₁ input from the first ground fault direction relay device and the output signal of the fifth logical product circuit 63 ₂ .

Branch load compensation inhibiting circuit 67, the output signal of the third AND circuit 63 ₃ and the fifth high level from the AND circuit 63 ₅ is inputted, the branch load compensation inhibition instruction signal to prohibit the branch load compensation Output.
When a high level output signal is input from the OR circuit 71, the branch load compensation circuit 68 outputs a branch load compensation instruction signal for performing branch load compensation.
Similar to the orientation circuit 29 shown in FIG. 2, when the branch load compensation prohibition instruction signal is input from the branch load compensation prohibition circuit 67, the orientation circuit 69 calculates the ground fault impedance based on the first line current I _1. perform the distance calculation to fault point (locating the accident point) by, when the branch load compensation instruction signal is inputted from the branch load compensation circuit 68, based on the current obtained by subtracting the branch load current from a first line current I ₁ Calculate the distance to the accident point (location of the accident point) using the ground fault impedance calculation method.

The second power supply terminal failure point locating device 50 ₂ is configured in the same manner as the first power supply terminal failure point locating device 50 ₁ described above.

Next, the operation of the first power supply terminal failure point locating device 50 ₁ when a ground fault occurs in the own line 1L will be described.

First, the first in the case where a ground fault occurs in the power supply end side (the first location range of the first power supply end fault location device 50 ₁ ) from the branch point of the own line 1L to the non-parallel branch line 5L. The operation of the power supply terminal failure point locating apparatus 50 ₁ will be described.
When a ground fault occurs at such an accident point, the orientation range determination circuit 70 of the accident point location circuit 60 divides the bus voltage Va by the first line current I ₁ to obtain a first impedance Z ₁ (Z ₁ = Va / I ₁ ) is calculated, and based on the calculated first impedance Z ₁ , it is determined that “the location range of the first power supply terminal failure point location device 50 ₁ is the one-stage location range A1”. High-level first and second determination result output signals VD ₁ and VD ₂ are output.
As a result, the output signal of the _fourth AND circuit 634 changes from the low level to the high level. Therefore, when the FD relay output signal _SFD is at the high level, the output signal of the _fifth AND circuit 635 changes from the low level. Since it becomes high level, a branch load compensation instruction signal is output from the branch load compensation prohibiting circuit 67 to the orientation circuit 69.
As a result, the orientation circuit 69 performs distance calculation (accident point location) to the accident point by a ground fault impedance calculation method based on the first line current I ₁ . As a result, in such a ground fault, since the first line current I ₁ flowing through the power supply end of the own line 1L is only the fault current, the fault point can be accurately determined.

Next, the operation of the first power supply terminal failure point locating device 50 ₁ when a ground fault occurs between the branch point of the own line 1L to the non-parallel branch line 5L and the branch point to the own branch line 3L. Will be described.
When a ground fault occurs at such an accident point, the orientation range determination circuit 70 of the accident point location circuit 60 divides the bus voltage Va by the first line current I ₁ to obtain a first impedance Z ₁ (Z ₁ = Va / I ₁ ) is calculated, and based on the calculated first impedance Z ₁ , it is determined that “the location range of the first power supply terminal failure point location device 50 ₁ is the two-stage location range A2”. Since the second determination result output signal VD ₂ of high level is output, when the FD relay output signal _SFD is high level, the output signal of the _sixth AND circuit 636 changes from low level to high level.
In this case, breaker 4 ₁ of the first by the earth fault by the first earth fault direction relay apparatus when it is preceded or interrupted simultaneously than the third breaker 4 ₃ of the first earth fault A high-level first trip signal S ₁ is input to the OR circuit 71 from the direction relay device. As a result, the output signal of the logical sum circuit 71 changes from the low level to the high level, so that the branch load compensation instruction signal is output from the branch load compensation circuit 68 to the orientation circuit 69.
As a result, the orientation circuit 69 starts the distance calculation (accident point location) to the accident point by the ground fault impedance calculation method based on the current obtained by subtracting the branch load current from the first line current I ₁ and the orientation error is determined. Do until convergence. Thereby, in such a ground fault, since the branch load current flows from the own line 1L to the unbalanced branch line 5L until the _first circuit breaker 41 is cut off, the fault point can be accurately determined. it can.

Next, the operation of the first power supply terminal failure point locator 50 ₁ when a ground fault occurs on the opposite end side of the branch point of the own line 1L to the own branch line 3L will be described.
When a ground fault occurs at such an accident point, since the impedance viewed from the power supply end of the own line 1L (that is, the first impedance Z ₁ ) is larger than the first threshold Th _1a , the accident point location circuit 60 since the self-line output signal of the Z comparison circuit 61 remains at the low level, the second aND circuit 63 _{and second} output signal of the remains at a low level. As a result, the output signal of the _third AND circuit 633 remains at a low level.
Further, since both line impedances (that is, both line impedances Z _a ) viewed from the power supply terminal of the own line 1L are equal to or less than the second threshold Th _2a , the output signal of both line Z comparison circuits 62 changes from low level to high level. Become. As a result, the polarity high output signal level of the output signal and a double line Z comparator circuit 62 of its own line Z comparator circuit 61 which is inverted is input to a high level by the inverter circuit 64 to the first AND circuit 63 ₁ Therefore, the output signal of the _first AND circuit 631 changes from the low level to the high level. The high-level output signal of the _first AND circuit 631 is extended by the extending circuit 65 for the time DL by extending the time axis.

Then, at the same time when the third breaker 4 ₃ placed on the opposite end side of the own line 1L is blocked by the third line selection relay built in the first opposing end fault point locating system 30 _1, the self when the fifth breaker 4 ₅ arranged at the load end side of the branch line 3L is cut off by the ground fault protective relay device for the mobile branch line 3L (not shown), the fault current of the own line 1L Since the current flows only from the power supply end toward the accident point (that is, the first line current I ₁ becomes large), the impedance viewed from the power supply end of the own line 1L (that is, the first impedance Z ₁ ) is the first. since falls below threshold Th _1a, the output-signal of the line Z comparator circuit 61 is changed from the low level to the high level. As a result, the output signal of the stretching circuit 65 because it remains as the high level, the second output signal of the AND circuit 63 ₂ is changed from the low level to the high level.
At this time, if the second contact signal S _C2 is at a high level (indicating that the _second circuit breaker 42 is not cut off), the output signal of the _third AND circuit 633 changes from a low level to a high level. Therefore, the branch load compensation prohibition instruction signal is output from the branch load compensation prohibition circuit 67 to the orientation circuit 69.
As a result, the orientation circuit 69 calculates the distance to the accident point by the ground fault impedance calculation method based on the first line current I ₁ . At this time, since the third and fifth circuit breakers 4 ₃ and 4 ₅ are simultaneously interrupted before the _first circuit breaker 4 ₁ , the first ground fault direction relay device causes the high level first Until the trip signal S ₁ is output (that is, until the first circuit breaker 4 ₁ is cut off), the first line current I ₁ flowing to the power supply terminal of the own line 1L is only a fault current. Therefore, since it is not necessary to perform branch load compensation, the fault point is accurately determined even when the distance to the fault point is calculated by the ground fault impedance calculation method based on the first line current I ₁ as described above. be able to.

In addition, when the unbalanced branch line 5L is laid on the opposite end side from the self-branch line 3L as shown in FIG. 7, the accident point having the same configuration as the accident point locating circuit 60 shown in FIG. orientation circuit (in FIG. 8, the first opposing end fault point locating system 80 ₁ is showing a structure of a fault point locating circuit 90 comprises.) the first and second opposing end fault point locating system having a 80 _1, By installing 80 ₂ (failure point locating device according to the second embodiment of the present invention) on the opposite end side of the own line 1L, it is possible to accurately determine the accident point in the same manner.

The setting of the branch load may be affixed to each terminal (opposite end and load end), but since it is a light load on holidays and late at night, it was calculated at an integrated ratio from the power sent from the power supply end A branch load may be pasted.
Furthermore, although the first and second power supply terminal fault location devices 10 ₁ , 10 ₂ ; 50 ₁ , 50 ₂ are individually configured, they may be configured integrally. The same applies to the first and second opposing end failure point locating devices 30 ₁ , 30 ₂ ; 80 ₁ , 80 ₂ .

The first and second power supply terminal failure point locating devices 10 ₁ and 10 ₂ which are failure point locating devices according to the first embodiment of the present invention and the first failure point locating device according to the first embodiment of the present invention. It is a figure for demonstrating 2nd opposing end failure point location apparatus 30 ₁ and 30 ₂ . First power supply terminal fault point locating system 10 ₁ is a block diagram showing the configuration of a fault point locating circuit 20 comprising shown in FIG. The first opposing end fault point locating system 30 ₁ is a block diagram showing the configuration of a fault point locating circuit 40 comprising shown in FIG. The first opposing end fault point locating system 30 ₁ is a block diagram showing a configuration of another fault point locating circuit 40a comprising shown in FIG. Is a diagram for explaining a first power supply terminal fault point locating system 50 ₁ is a fault point locating system according to a second embodiment of the present invention. FIG. 6 is a block diagram showing a configuration of a fault location circuit 60 included in the first power supply terminal fault location apparatus 50 ₁ shown in FIG. 5. Is a diagram for explaining a second embodiment the first and second opposing end fault point locating system is a fault point locating system according to 80 _1, 80 ₂ of the present invention. The first opposing end fault point locating system 80 ₁ shown in FIG. 7 is a block diagram showing the configuration of a fault point locating circuit 90 comprising.

1 power supply 2 ₁ , 2 ₂ first and second transformers 3 _{1 to} 3 _{4 first} to _fourth current transformers 4 ₁ to 4 _{7 first} to _seventh circuit breakers 10 ₁ , 10 ₂ , 50 ₁ , 50 ₂ First and second power supply terminal failure point locating devices 20, 40, 60, 90 Accident point locating circuits 21, 41, 61, 91 Own line Z comparison circuit 22, 42, 62, 92 Both line Z comparison circuits 23 _{1-23 5} first through aND circuit 24 ₁ of the fifth, 24 _2, 44 _1, 44 ₂ first and second inverter circuits 25,65,95 spreading circuit 27,47,67,97 branch load compensation inhibiting circuit 28,48,68,98 branch load compensation circuit 29,49,69,99 orientation circuit 30 _1, 30 _2, 80 _1, 80 ₂ first and second opposing end fault point locating system 43 ₁ - 43 ₄ the first to fourth AND circuit 63 ₁ to 63 _6, 93 ₁ to 93 ₆ first to sixth logical product of Road 64, 94 inverter circuit 70, 100 orientation range determining circuit 71,101 OR circuit 1L own line 2L other line 3L own branch line 4L other branch lines 5L unbalanced branch line Va bus voltage Vb opposite ends bus voltage V _0b opposite ends Zero-phase voltages I _{1 to} I ₄ First to fourth line currents Z _{1 to} Z ₄ First and fourth impedances Z _a and Z _b Both line impedances Z _1max and Z _2max First and second maximum impedances Th _{1a, Th 2a, Th 1b,} Th 2b first and second threshold DL stretching time VD _1, VD ₂ first and second determination result output signal A1, A2 1-stage and two-stage orientation range S _FD FD relay output signal S ₁ to S ₄ first to fourth trip signal T _RY relay judgment time T _CB breaker breaking time of

Claims (13)

The own line (1L) and the other line (2L) laid between the power source side bus and the opposite end bus on the opposite end side, the own branch line (3L) branched from the own line and the other line, and A failure point locating device (10 ₁ ) installed on the power supply end side of a balanced two-line power transmission line having another branch line (4L),
When a ground fault occurs in the own line, branch load compensation is performed on the own line current (I ₁ ) flowing from the power supply end of the own line toward the accident point, and the fault is calculated by the ground fault impedance calculation method. Accident point locating circuit (20; 60) that performs the distance calculation of
Other terminal breakers (4 ₃ , 4 ₅ ) installed on the opposite end side of the own line and the load end side of the own branch line based on the change of the own line impedance and both line impedances When detecting that is interrupted, the distance to the fault point is calculated by the ground fault impedance calculation method based only on the current line current without performing the branch load compensation,
A failure point locating device characterized by that. The accident point locating circuit (20; 60)
Own line impedance comparison circuit (21; 61) for outputting an output signal when own line impedance (Z ₁ ) calculated by dividing bus voltage (Va) by own line current is equal to or less than a first threshold (Th _1a ) When,
Both line impedances (Z _a ) calculated by dividing the bus voltage by the sum of the own line current and the other line current (I ₂ ) flowing through the power supply end of the other line are the second threshold (Th _2a ) Both line impedance comparison circuit (22; 62) that outputs an output signal when
An inverter circuit (24 ₁ ; 64) for inverting the polarity of the output signal of the own line impedance comparison circuit;
A first logical product circuit (23 ₁ ; 63 ₁ ) that takes the logical product of the output signal of the two-line impedance comparison circuit and the output signal of the inverter circuit;
A stretching circuit (25; 65) for stretching the time axis of the output signal of the first AND circuit by a time (DL);
A second AND circuit (23 ₂ ; 63 ₂ ) that takes the logical product of the output signal of the first AND circuit and the output signal of the extension circuit;
An orientation circuit (29; 69) for calculating the distance to the accident point by the ground fault impedance calculation method;
Branch load compensation prohibition / execution instructing means (27, 28; 67, 68) for instructing the orientation circuit to prohibit or execute the branch load compensation according to the polarity of the output signal of the second AND circuit; ,
The failure point locating apparatus according to claim 1, comprising: The extension time includes a relay judgment time (T _RY ) of a ground fault direction relay device built in the fault location device, and a circuit breaker cutoff time of the own circuit breaker installed at the power supply terminal of the own line The failure point locating device according to claim 2, wherein the failure point locating device is longer than a total time of (T _CB ). Said fault point orientation circuit, the other line of the next line breaker installed in the power source terminal side (4 ₂₎ provided that the is not interrupted, the other based on a change of the own line impedance and both line impedance When it is detected that the terminal breaker has been cut off, the distance to the fault point is calculated by a ground fault impedance calculation method based only on the current line current without performing the branch load compensation. Item 4. A fault location apparatus according to any one of Items 1 to 3. The accident location circuit (60)
An orientation range determination circuit (70) for determining an orientation range of the fault location device based on an own line impedance calculated by dividing the bus voltage by the own line current;
When the branch load compensation prohibition / execution instructing unit (67, 68) determines that the orientation range determination circuit determines that the orientation range of the failure point location device is a one-stage orientation range, Instructing prohibition of branch load compensation,
The failure point locating device according to any one of claims 2 to 4, wherein   The one-step location range of the location range of the failure point location device is determined from the power supply end of the own line to the own branch of the unbalanced branch line (5L) laid on the power supply end side of the own line from the own branch line. 6. The failure point locating device according to claim 5, wherein the failure point locating device is in a range up to the line side. The other failure point locating device (10 ₂ ; 50 ₂ ) installed on the power supply end side of the other line has the same configuration as the failure point locating device and is integrally formed. The fault location apparatus according to any one of claims 1 to 6. The own line (1L) and the other line (2L) laid between the power source side bus and the opposite end bus on the opposite end side, the own branch line (3L) branched from the own line and the other line, and A failure point locating device (30 ₁ ; 80 ₁ ) installed on the opposite end side of the balanced two-line transmission line having another branch line (4L),
When a ground fault occurs in the own line, branch load compensation is performed on the own line current (I ₃ ) flowing from the opposite end of the own line toward the fault point, and the fault is calculated by the ground fault impedance calculation method. An accident point locating circuit (40; 40a; 90) for calculating the distance of
In the fault location circuit, the other terminal breakers (4 ₁ , 4 ₅ ) installed on the power supply end side of the own line and the load end side of the own branch line are cut off based on the change of the own line impedance. Detecting that, performing the distance calculation to the fault point by the ground fault impedance calculation method based only on the current line current without performing the branch load compensation,
A failure point locating device characterized by that. The accident location circuit (40)
Own line impedance comparison circuit (41) for outputting an output signal when the own line impedance (Z ₃ ) calculated by dividing the opposite-end bus voltage (Vb) by the own line current is equal to or less than the first threshold (Th _1b ) When,
Both line impedances (Z _b ) calculated by dividing the opposite-end bus voltage by the sum of the own-line current and the other-line current (I ₄ ) flowing on the opposite-end side of the other line are the second threshold value (Z _b ). Th _2b ) or less, both line impedance comparison circuit (42) that outputs an output signal,
An inverter circuit (44 ₁ ) for inverting the polarity of the output signal of the two-line impedance comparison circuit;
A logical product circuit (43 ₁ ) that takes a logical product of the output signal of the own line impedance comparison circuit and the output signal of the inverter circuit;
An orientation circuit (49) for calculating the distance to the accident point by the ground fault impedance calculation method;
Branch load compensation prohibition / execution instructing means (47, 48) for instructing the orientation circuit to prohibit or execute the branch load compensation according to the polarity of the output signal of the AND circuit;
The accident point locating device according to claim 8, comprising: The accident point locating circuit (40a)
Own line impedance comparison circuit (41) for outputting an output signal when the own line impedance (Z ₃ ) calculated by dividing the opposite-end bus voltage (Vb) by the own line current is equal to or less than the first threshold (Th _1b ) When,
An inverter circuit (51) for inverting the polarity of the output signal of the own line impedance comparison circuit;
Output signals of the output signal (S _OVG) or the output signal of the installed ground fault overcurrent relay device to the opposite end of its own line and the inverter circuit of the installed ground fault over-voltage relay device to the opposite end generating line A first AND circuit (52) that takes the logical product of:
A stretching circuit (53) for stretching the time axis of the output signal of the first AND circuit by a time (DL);
A second AND circuit (43 ₁ ) that takes the logical product of the output signal of the own line impedance comparison circuit and the output signal of the extension circuit;
An orientation circuit (49) for calculating the distance to the accident point by the ground fault impedance calculation method;
Branch load compensation prohibition / execution instructing means (47, 48) for instructing the orientation circuit to prohibit or execute the branch load compensation according to the polarity of the output signal of the second AND circuit;
The accident point locating device according to claim 8, comprising: The accident location circuit (90)
Self-line impedance comparison circuit (91) that outputs an output signal when the self-line impedance (Z ₃ ) calculated by dividing the opposite-end bus voltage (Vb) by the self-line line current is equal to or less than the first threshold (Th _1b ). When,
Both line impedances (Z _b ) calculated by dividing the opposite-end bus voltage by the sum of the own-line current and the other-line current (I ₄ ) flowing on the opposite-end side of the other line are the second threshold value (Z _b ). Th _2b ) or less, both line impedance comparison circuit (92) that outputs an output signal,
An inverter circuit (94) for inverting the polarity of the output signal of the own line impedance comparison circuit;
A first logical product circuit (93 ₁ ) that takes the logical product of the output signal of the two-line impedance comparison circuit and the output signal of the inverter circuit;
A stretching circuit (95) for stretching the time axis of the output signal of the first AND circuit by a time (DL);
A second logical product circuit (93 ₂ ) that takes the logical product of the output signal of the own line impedance comparison circuit and the output signal of the extension circuit;
An orientation circuit (99) for calculating the distance to the accident point by the ground fault impedance calculation method;
An orientation range determination circuit (100) for determining an orientation range of the fault location device based on an own line impedance calculated by dividing the opposite-end bus voltage by the own line current;
According to the polarity of the output signal of the second AND circuit, the location circuit is instructed to prohibit the branch load compensation, and “the location range of the fault location device is a one-step location range”. A branch load compensation prohibiting circuit (97) for instructing the prohibition of the branch load compensation to the orientation circuit when the orientation range determining circuit determines;
The failure point locating apparatus according to claim 8, comprising:   The one-step location range of the location range of the fault location device is determined to be that of the unbalanced branch line (5L) that is laid from the opposite end of the own line to the opposite end side of the own line rather than the own branch line. 12. The failure point locating device according to claim 11, wherein the failure point locating device is in a range up to the line side. Another failure point locating device (30 ₂ ; 80 ₂ ) installed on the opposite end side of the other line has the same configuration as the failure point locating device and is integrally formed. The fault location apparatus according to any one of claims 8 to 12.