JP2008161011A - Short circuit direction relay device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a short circuit direction relay device for power supply end and opposite end, capable of remarkably shortening a fault eliminating time. <P>SOLUTION: A first power supply end short circuit direction relay device 10<SB>1</SB>disposed on a power supply end of an own line 1L of a parallel dual power transmission line includes a trip signal generating circuit 20 for generating a first trip signal S<SB>1</SB>for interrupting a first breaker 4<SB>1</SB>provided on the power supply end side of the own line 1L when detecting a short circuit fault in the own line 1L. The trip signal generating circuit 20 includes an own line fault determining circuit 25 for obtaining a value calculated by dividing the difference between a first short circuit current I<SB>1</SB>and a second short circuit current I<SB>2</SB>by the sum of the first short circuit current I<SB>1</SB>and the second short circuit current I<SB>2</SB>, and outputting an output signal when the obtained value is larger than a threshold value; and a third AND circuit 23 for ANDing between an output signal of the own line fault determining circuit 25 and a second contact point signals S<SB>C2</SB>to be inputted from a second breaker 4<SB>2</SB>provided on the power supply end side of the other line 2L. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a short-circuit direction relay device, and more particularly to a short-circuit direction relay device suitable for installation on the power supply end side and the opposite end side of a balanced two-line transmission line.

Generally, a short-circuit direction relay device (DS) used for protection in the case of a short-circuit accident in a power system is a quantity of electricity (line voltage and phase current) of its own line (a transmission line in which the short-circuit direction relay device is installed). ) To determine the occurrence of a short-circuit accident based on the magnitude and direction of other short-circuit direction relays installed on the transmission line behind the opposite end (non-power source) Cooperation (accumulation of 0.4 s to 0.5 s) is taken.
Therefore, in the short-circuit direction relay device installed on the power supply end side, as will be described below, the accident removal time becomes long, so the short-circuit direction relay device is used as a back-up protection in the balanced two-line transmission line, The accident removal time is shortened by installing a separate main protection relay device that operates instantly due to a short circuit accident in the protection section.

As shown in FIG. 7, a first power transmission line 1L (hereinafter referred to as “own line 1L”) and a second power transmission line 2L (hereinafter referred to as “others”) branched from a bus line supplied with power from the power source 1. Short circuit direction relay devices (hereinafter referred to as “first and second power supply terminal short circuit direction relay devices 110 ₁ , 110 ₂ ”) on the power supply end side (bus side) of the line 2L ”), respectively. The short-circuit direction relay device (hereinafter referred to as “first and second opposite-end short-circuit direction relay devices 120 ₁ , 120” is also installed on the opposite end side (opposite side of the bus line) of the own line 1L and the other line 2L. ₂ ”) are installed.

The first power supply terminal short-circuit direction relay device 110 ₁ is referred to as a line voltage (hereinafter referred to as “first line voltage V ₁ ”) input from a _first instrument transformer 21 provided on the bus. And the phase current (hereinafter referred to as “first short-circuit current I ₁ ”) input from the _first current transformer 3 ₁ installed on the power supply end side of the own line 1L. When the occurrence of a short circuit accident in the own line 1L is detected, a first trip signal S ₁ for breaking the _first circuit breaker 41 installed on the power supply end side of the own line 1L is generated.
Relay device 110 ₂ and the second power supply terminal short circuit direction, the second instrument current transformer installed in the first line voltage V ₁ and the other line 2L input from the first voltage transformer 2 ₁ When the occurrence of a short-circuit fault in the other line 2L is detected based on the phase current input from the device 3 ₂ (hereinafter referred to as “second short-circuit current I ₂ ”), it is installed on the power supply end side of the other line 2L. a second trip signal S ₂ for cutting off the second circuit breaker 4 ₂ generated was.

The first opposing end short-circuit direction relay device 120 ₁ is connected between lines input from a _second instrument transformer 2 ₂ provided on the opposing end bus (hereinafter referred to as “opposing end bus”). A voltage (hereinafter referred to as “second line voltage V ₂ ”) and a phase current (hereinafter referred to as “hereinafter referred to as“ _second line voltage V ₂ ”) input from a _third current transformer 33 installed on the opposite end side of the own line 1L. When the occurrence of a short circuit accident in the own line 1L is detected based on the third short circuit current I ₃ "), the third circuit breaker 4 ₃ installed on the opposite end side of the own line 1L is cut off. to generate a third of the trip signal S _3.
The second opposite-end short-circuit direction relay device 120 ₂ has a fourth line voltage V ₂ input from the second instrument transformer 2 ₂ and a fourth line installed on the opposite end side of the other line 2L. phase current input from the current transformer 3 ₄ detects a short circuit occurrence in the other line 2L based on (hereinafter, referred to as. "fourth short circuit current I ₄ of") and the opposite end of the other line 2L A fourth trip signal S ₄ for breaking the fourth circuit breaker 4 ₄ installed on the side is generated.

The first power supply terminal short-circuit direction relay device 110 ₁ includes a trip signal generation circuit 130 as shown in FIG. 8 in order to generate the _first trip signal S ₁ .
Here, the trip signal generation circuit 130 includes a relay determination circuit 131 and a delay circuit (timer) 132.

Relay determining circuit 131, generated in the instantaneous element operating range of its own line 1L based on the first short-circuit current I ₁ of the magnitude and the first line voltage V ₁ and the first phase relation short-circuit current I ₁ When the detected short-circuit accident is detected, a high-level first instantaneous element trip signal ST _a1 is output, and the magnitude of the first short-circuit current I ₁ , the first line voltage V _1, and the first short-circuit current I ₁ are output. When a short-circuit accident occurring within the time-limit element operation range of the own line 1L is detected based on the phase relationship, a high-level first time-limit cutoff output signal is output to the delay circuit 132.
The delay circuit 132 generates a first first time limiting element trip signal ST _b1 a time-limit cutoff output signal delayed by a timed coordination time T1 the _first relay determining circuit 131. Here, timed coordination time T1 ₁ is set for the timed coordination with other short direction relay apparatus installed at opposite ends behind the transmission line of its own line 1L (not shown).
The first instantaneous element trip signal ST _a1 and the first time limit element trip signal ST _b1 are output to the _first circuit breaker 41 as the first trip signal S ₁ .

Second power supply terminal short-circuit direction relay device 110 ₂ includes a trip signal generation circuit (not shown) having the same configuration as trip signal generation circuit 130 described above.

The first opposite-end short-circuit direction relay device 120 ₁ includes a trip signal generation circuit 140 as shown in FIG. 9 in order to generate the _third trip signal S ₃ .
Here, the trip signal generation circuit 140 includes a relay determination circuit 141 and a delay circuit (timer) 142.

Relay determining circuit 141, generated in the instantaneous element operating range of the third short-circuit current I ₃ of the size and the own line 1L based on the phase relation of the second line voltage V ₂ and the third short-circuit current I ₃ When the detected short-circuit fault is detected, a high-level third instantaneous element trip signal ST _a3 is output, and the magnitude of the third short-circuit current I ₃ , the second line voltage V _2, and the third short-circuit current I ₃ are output. When a short-circuit accident occurring within the time-limit element operation range of the own line 1L is detected based on the phase relationship, a high-level third time-limit cutoff output signal is output to the delay circuit 142.
The delay circuit 142 delays the third time-limit cutoff output signal of the relay determining circuit 141 only timed coordination time T1 _3. Here, the time cooperation time T1 ₁ (for example, 800 ms) set in the delay circuit 132 shown in FIG. 8 is set to be longer than the time cooperation time T1 ₃ (for example, 400 ms) for the time cooperation. (T1 ₁ > T1 ₃ ).

The second opposite-end short-circuit direction relay device 120 ₂ includes a trip signal generation circuit (not shown) having the same configuration as the trip signal generation circuit 140 described above.

If a short circuit accident occurs at time t ₀ shown in FIG. 10 within the time limit element operation range of the own line 1L that is the protection section of the first power supply terminal short-circuit direction relay device 110 ₁ , the accident current (short circuit current) is Since the current flows toward the accident point as indicated by the broken arrow in FIG. 7, the direction of the short-circuit current (first to third short-circuit currents I _{1 to} I ₃ ) is the same as the operation direction (internal direction = + direction). A certain first power supply terminal short-circuit direction relay device 110 ₁ , a second power supply terminal short-circuit direction relay device 110 _2, and a first opposing terminal short-circuit direction relay device 120 ₁ operate.

As described above, the time cooperation time T1 ₃ (= 400 ms) of the first opposing short-circuit direction relay device 120 ₁ is greater than the time cooperation time T1 ₁ (= 800 ms) of the first power supply terminal short-circuit direction relay device 110 _1. because even short, first, the first opposing end short direction relay device 120 ₁ is operated to shut off the third breaker 4 ₃ placed on the opposite end of its own line 1L. At this time, the third circuit breakers 4 _3, as shown in FIG. 10, the first opposing end short direction relay device 120 _first relay determination time T _RY (= 50ms) and timed coordination time T1 ₃ has elapsed Although it is interrupted by the _third trip signal S ₃ output from the first opposite-end short-circuit direction relay device 120 ₁ at time t ₂ , the third circuit breaker 4 ₃ is completely interrupted at time t ₂ . The time t ₃ when the circuit breaker breaking time T _CB (= 50 ms) has elapsed from t ₂ is reached.

When the third circuit breaker 4 ₃ is completely cut off at time t ₃ , the fault current (short-circuit current) flows only from the power supply end of the own line 1L toward the fault point (that is, as shown in FIG. 10). Since only the first short-circuit current I ₁ flows), only the first power supply end short-circuit direction relay device 110 ₁ continues to operate, and the first circuit breaker 4 ₁ installed on the power supply end side of the own line 1L. Shut off. At this time, the first breaker 4 _1, the accident occurrence time t ₀ a first power supply terminal short circuit direction relay device 110 _first relay determination time T _RY (= 50ms) and time the timed coordination time T1 ₁ has elapsed Although it is interrupted by the _first trip signal S ₁ output from the first power supply short-circuit direction relay device 110 ₁ at t ₄ , the first circuit breaker 4 ₁ is completely interrupted at time t ₄ breaker breaking time from T _CB (= 50ms) the time t ₅ has elapsed.

Patent Document 1 listed below includes a direction element for detecting a phase difference between an input current and an input voltage, an input current in order to enable detection of an accident and a protection operation output continuously for a time required for protection coordination. An overcurrent element that detects the magnitude of the current, and a determination unit that determines the presence or absence of a short-circuit accident from the phase difference and current magnitude detected by both of these elements, and sends a protective operation output when it is determined that there is a short-circuit accident Then, on the condition that this determination unit determines that a short-circuit accident has occurred, the magnitude of the short-circuit accident current is detected from the input current to determine whether the short-circuit accident continues, and the accident continues. The accident continuation detection means that sends out the protection operation output when it is determined that the protection operation output is output, and the protection operation output that is output from the determination unit and the accident continuation detection means after the time limit necessary for protection coordination with other protection relays on the power system. Timed out to send With the door, short directional relay is disclosed.
Patent Document 2 below includes an overcurrent relay that operates when a differential current flowing in a balanced two-line transmission line of a power system is equal to or greater than a predetermined value, and a short-circuit selection relay that inputs the differential current and the bus voltage. In the line selection relay device that selectively cuts off the accident line of the two-line transmission line, in order to prevent the circuit breaker trip signal from being erroneously output in the case of a rear failure in which circulating current flows through the balanced two-line transmission line due to a short circuit on the bus, First and second current direction relays for detecting the direction of current flowing in each line of the two-line power transmission line are provided, and when an AND condition is established for each output of the overcurrent relay, the short-circuit selection relay, and the first and second current direction relays A line selection relay device for tripping a circuit breaker is disclosed.
JP 2000-92693 A JP-A-11-164470

However, in the first power supply short-circuit direction relay device 110 ₁ described above, when a short-circuit accident occurs within the time-limited element operation range of the own line 1L, the first circuit breaker 4 ₁ starts from the accident occurrence time t _0. relay determination time T _RY, timed coordination time T1 ₁ and circuit breaker interrupting the total time of the time _{T CB (= 50ms + 800ms +} 50ms = 900ms) because only interrupted at the time t ₅ has elapsed (see FIG. 10), to remove the short circuit However, there is a problem that it takes time and adversely affects the equipment.

In addition, even the first opposing end short direction relay device 120 _1, the sum of the third breaker 4 ₃ accident occurrence time t ₀ from the relay determination time T _RY, timed coordination time T1 ₃ and breaker interruption time T _CB time (= 50ms + 400ms + 50ms = 500ms) to be cut off at the time t ₃ when has elapsed (see FIG. 10), takes time to remove the short-circuit failure, there is a problem that an adverse effect on equipment.

  An object of the present invention is to provide a short-circuit direction relay device for a power supply end and an opposite end that can greatly reduce the accident removal time.

The first short-circuit direction relay device of the present invention is a balanced two-line transmission composed of a local line (1L) and another line (2L) laid between a bus on the power supply end side and an opposite end bus on the opposite end side. A short-circuit direction relay device (10 ₁ ) installed on the power supply end side of the own line of the electric wire, and upon detecting occurrence of a short circuit accident in the own line, the own line provided on the power supply end side of the own line A trip signal generation circuit (20) for generating a trip signal (S ₁ ) for breaking the circuit breaker (4 ₁ ) is provided, and the trip signal generation circuit is directed from the power supply terminal of the own line toward the accident point. The difference between the flowing own line short-circuit current (I ₁ ) and the other line short-circuit current (I ₂ ) flowing from the opposite end of the own line toward the fault point and the sum of the own line short-circuit current and the other line short-circuit current When a short-circuit accident is detected based on the ratio, the trip signal is instantaneously Characterized in that it comprises a trip signal generating means for generating.
Here, the trip signal generating means, the other line of the next line breaker installed in the power source terminal side (4 ₂₎ provided that the is not interrupted, short circuit in the self-line on the basis of the ratio When occurrence is detected, the trip signal may be generated instantaneously.
The trip signal generating means obtains a value obtained by dividing the difference between the short-circuit current of the own line and the short-circuit current of the other line by the sum of the short-circuit current of the own line and the short-circuit current of the other line. If there is a logic that takes the logical product of the own line fault judgment circuit (25) that outputs an output signal, the output signal of the own line fault judgment circuit, and the contact signal (S _C2 ) input from the adjacent circuit breaker And a product circuit (23).
The threshold may be set to “1-X / 100” when an X% section from the power supply end to the opposite end of the own line is set as a time-reduced protection section.
The time-limited shortening protection section may be a section of 80 to 85% from the power supply end to the opposite end of the own line.
The other short-circuit direction relay device (10 ₂ ) installed on the power supply end side of the other line may have the same configuration as the short-circuit direction relay device and may be configured integrally.
The second short-circuit direction relay device of the present invention is a balanced two-line transmission composed of a local line (1L) and another line (2L) laid between a bus on the power supply end side and an opposite end bus on the opposite end side. A short-circuit direction relay device (30 ₁ ) installed on the opposite end side of the own line of the electric wire, and when the occurrence of a short circuit accident in the own line is detected, the own line provided on the opposite end side of the own line A trip signal generating circuit (40) for generating a trip signal (S ₃ ) for interrupting the circuit breaker (4 ₃ ), wherein the trip signal generating circuit has a short-circuit current from the other line on the opposite end side; When a short-circuit accident is detected based on the ratio of wrapping around the own line, a trip signal generating means that instantaneously generates the trip signal is provided.
Here, the trip signal generating means, the other line facing end side adjacent line circuit breaker installed in the (4 ₄₎ on condition that is not interrupted, short circuit in the self-line on the basis of the ratio When occurrence is detected, the trip signal may be generated instantaneously.
The trip signal generating means has its own line short circuit current (I ₃ ) flowing from the opposite end of the own line toward the fault point, and another line short circuit current (I ₄₎ flowing from the opposite end of the other line toward the fault point. ) And the absolute value of the difference between the current and the short circuit current is divided by twice the local short circuit current, and an output signal is output when the obtained value is greater than the first threshold and smaller than the second threshold. And a logical product circuit (43) for taking the logical product of the output signal of the own line fault judgment circuit and the contact signal (S _C4 ) input from the adjacent circuit breaker. You may prepare.
The first and second threshold values may be determined according to errors including a current transformer error, a relay error, and a line constant error at the opposite end.
The trip signal generating means may instantly generate the trip signal on condition that another short-circuit direction relay device (30 ₂ ) installed on the opposite end side of the other line is inoperative. .
The other short-circuit direction relay device (30 ₂ ) installed on the opposite end side of the other line may have the same configuration as that of the short-circuit direction relay device and may be integrally configured.

The short-circuit direction relay device of the present invention has the following effects.
(1) The short-circuit direction relay device installed on the power supply end side of the balanced two-line transmission line has its own line short-circuit current flowing from the power supply end of the own line toward the fault point and from the power supply end of the other line to the fault point. If a short-circuit fault is detected based on the ratio of the difference between the short-circuit current of the other line that flows and the sum of the short-circuit current of the own line and the short-circuit current of the other line, a trip signal is generated instantaneously. Can be greatly shortened.
(2) The short-circuit direction relay device installed on the opposite end side of the balanced two-line transmission line instantaneously outputs a trip signal when a short-circuit fault is detected on the opposite end side based on the ratio of the short-circuit current flowing from the other line to the own line. Therefore, the removal time of a short-circuit accident that occurred on the own line can be greatly shortened.
(3) Since the accident continuation time is also greatly shortened, the adverse effects on the facilities at the time of the accident can be reduced.
(4) Since it is possible to omit the main protection relay device, the investment cost to the facility can be reduced.

  Based on the ratio of the difference between the short circuit current and the short circuit current of the other line and the sum of the short circuit current and the short circuit current of the self line When a short-circuit accident is detected, a trip signal is generated instantaneously, and the short-circuit direction relay installed on the opposite end of the own line is short-circuited based on the ratio of the short-circuit current flowing from the other line to the own line on the opposite end side. This was realized by generating a trip signal instantly when an accident was detected.

Embodiments of the short-circuit direction relay device of the present invention will be described below with reference to the drawings.
First, a short-circuit direction relay device according to a first embodiment of the present invention will be described with reference to FIGS.
The short-circuit direction relay device according to the present embodiment is a short-circuit direction relay device installed on the power supply end side of the balanced two-line transmission line. Focusing on the fact that the ratio of the current (first short-circuit current I ₁ ) is larger than the ratio of the fault current (second short-circuit current I ₂ ) of the healthy line, If a short circuit fault is detected based on the ratio of the difference between the fault current of the current line and the fault current of the healthy line and the sum of the fault current of the fault line and the sum of the fault current of the healthy line (the former divided by the latter), the trip signal is It is generated instantaneously.

Therefore, the first power supply short-circuit direction relay device 10 ₁ (short-circuit direction relay device according to the first embodiment of the present invention) shown in FIG. 1 is installed on the power supply end side of the other line 2L which is a healthy line. the second circuit breaker 4 ₂ is not blocked, and (1) when detecting a short circuit generated in its own line 1L with accident circuits based on the own line accident determination condition shown in the expression first trip signal It is different from the conventional first power supply terminal short-circuit direction relay device 110 ₁ shown in FIG. 7 in that it has a function of generating S ₁ instantaneously.
(I ₁ −I ₂ ) / (I ₁ + I ₂ ) ≧ 0.2 (1)
Here, the threshold value is determined by the time-reduced protection section (that is, the range of the own line 1L that instantaneously generates the _first trip signal S1 in response to a short-circuit accident), and from the power supply end of the own line 1L to the opposite end. When the section of X% is set as the time-reduced protection section, the threshold value = 1−X / 100. Therefore, the threshold value = 0.2 in the equation (1) is used when the 80% section from the power supply end to the opposite end of the own line 1L is set as the time-reduced protection section. Note that the time reduction protection section requires a margin of about 15 to 20% in consideration of errors such as current transformer errors (CT errors), relay errors, and line constant errors. The section is 80 to 85% up to the opposite end.

That is, the first power supply terminal short circuit direction relay device 10 _1, the second contact signal S _C2 is at a high level (blocked second breaker 4 ₂ inputted from the second circuit breaker 4 ₂ indicates that no.), and the second short inputted from the first short-circuit current I ₁ and the second current transformer 3 ₂ inputted from the first current transformer 3 ₁ A value obtained by dividing the difference from the current I ₂ (= I ₁ −I ₂ ) by the first short-circuit current I ₁ , the second short-circuit current I ₂ and the sum (I ₁ + I ₂ ) is a threshold value (= 0.2). conditions, to generate a first trip signals S ₁ instantaneously be at least.
To achieve this, the first power supply terminal short circuit direction relay device 10 _1, instead of the trip signal generating circuit 120 shown in FIG. 8, includes a trip signal generating circuit 20 shown in FIG.

  As shown in FIG. 2, the trip signal generation circuit 20 includes a relay determination circuit 21, a delay circuit (timer) 22, a logical product circuit 23, and an own line fault determination circuit 25.

Relay determining circuit 21, similarly to the relay determining circuit 131 shown in FIG. 8, the first short-circuit current I ₁ of the magnitude and the first line voltage V ₁ and the first phase relation short-circuit current I ₁ Based on this, when a short-circuit accident occurring within the instantaneous element operating range of the own line 1L is detected, a high-level first instantaneous element trip signal ST _a1 is output, and the magnitude of the first short-circuit current I ₁ and the first line are output. When a short-circuit accident that occurs within the time-limit element operation range of the own line 1L is detected based on the phase relationship between the inter-voltage V ₁ and the first short-circuit current I ₁ , the delay circuit 22 And output to the AND circuit 23.
Delay circuit 22, like the delay circuit 132 shown in FIG. 8, generates a first first time limiting element trip signal ST _b1 a time-limit cutoff output signal delayed by a timed coordination time T1 the _first relay determining circuit 21 To do.
Own line accident judging circuit 25, the difference between the first short-circuit current I ₁ and the second short-circuit current I ₂ (= I ₁ -I ₂₎ the first short-circuit current I ₁ and the second short-circuit current I ₂ And the sum (I ₁ + I ₂ ) is obtained, and if the obtained value is equal to or greater than the threshold (= 0.2), a high level output signal is output.
The logical product circuit 23 takes the logical product of the first timed interruption output signal of the relay determination circuit 21, the output signal of the own line fault determination circuit 25, and the second contact signal S _C2 to obtain the first instantaneous trip signal ST. Generate _c1 . Here, the first time-shut-off output signal of the relay determination circuit 21 is input to the logical product circuit 23 when the relay determination circuit 21 does not detect a short-circuit accident (first power supply short-circuit direction connection). in order that the collector 10 ₁ first instantaneous trip signal ST _c1) of a high level when no operation is not erroneously output.
The first instantaneous element trip signal ST _a1 , the first time limit element trip signal ST _b1, and the first instantaneous trip signal ST _c1 are output to the _first circuit breaker 41 as the first trip signal S ₁ .

  Next, the operation of the trip signal generation circuit 20 when a short circuit accident occurs within the time limit element operation range of the own line 1L shown in FIG. 1 will be described with reference to FIG.

When a short circuit accident occurs at time t ₀ within the time limit element operation range of the own line 1L, the direction of the short circuit current (first to third short circuit currents I _{1 to} I ₃ ) is the operation direction (internal direction = + direction). The same first power supply terminal short-circuit direction relay device 10 ₁ , second power supply terminal short-circuit direction relay device 10 _2, and first opposite-end short-circuit direction relay device 120 ₁ operate (see FIG. 7).

The relay determination circuit 21 of the trip signal generation circuit 20 included in the first power supply terminal short-circuit direction relay device 10 ₁ has its own line 1L based on the first line voltage V ₁ and the first short-circuit current I _1. It is determined that a short-circuit accident has occurred within the time limit element operation range, and a high-level first time cut-off output signal is output.
The first short-circuit current I ₁ and the second short-circuit current difference between I ₂ (= I ₁ -I ₂₎ the first short-circuit current I ₁ and the second short-circuit current I ₂ and the sum (I ₁ + I _If the value divided by ₂ ) is equal to or greater than “0.2”, the own line fault determination circuit 25 determines that a short circuit fault has occurred in the own line 1L, and outputs a high-level output signal.
As a result, the second contact signal S _C2 input from the second circuit breaker 4 ₂ When it is high level, the first instantaneous trip signal ST _c1 of a high level from the AND circuit 23 is output.

Trip Consequently, the first trip signals S ₁ of high level at time t ₁ that has elapsed since the accident occurrence time t ₀ by a first power supply terminal short circuit direction relay device 10 ₁ of the relay determination time T _RY (50 ms) is output from the signal generating circuit 20 to the first breaker 4 _1.

At this time, also in the first opposing end short-circuit direction relay device 120 ₁ , as described with reference to FIGS. 9 and 10, the second opposing end short-circuit direction relay device 120 ₂ from the accident occurrence time t ₀ . The high-level third trip signal S ₃ is the third circuit breaker at time t ₂ when the total time (= 50 ms + 400 ms = 450 ms) of the relay determination time T _RY (50 ms) and the timed coordination time T1 ₃ (400 ms) has elapsed. 4 is outputted to _3, the time t ₁ of the first trip signals S ₁ of high level is output, as shown in FIG. 3, the time the third trip signal S ₃ of the high level is outputted t Faster than ₂ .

Accordingly, the first breaker 4 ₁ is completely shut off to the third circuit breaker 4 earlier than _3, the time t _1a that has elapsed from time t ₁ only breaker interruption time T _CB (50ms). As a result, the first circuit breaker 4 ₁ is t ₅ −t _1a = T ₁ as compared with the case of the conventional first power supply terminal short-circuit direction relay device 110 ₁ shown by the broken line in FIG. 3 (see FIG. 10). It can be shut off as early as ₁ (= 800 ms).

When the first circuit breaker 4 ₁ is completely cut off, the fault current flows only from the power supply end of the other line 2L toward the fault point, so the first opposite-end short-circuit direction relay device 120 ₁ continues to operate. Thus, the third circuit breaker 4 ₃ is completely disconnected at time t ₃ when the circuit breaker interruption time T _CB (50 ms) has elapsed from time t ₂ . Therefore, the third circuit breaker 4 ₃ is completely cut off at the same time t ₃ as in the conventional case shown in FIG.

By configuring similarly to the first power supply terminal short circuit direction relay device 10 ₁ is also the second power supply terminal short circuit direction relay device 10 _2, when a short-circuit fault occurs in the time limit elements operating range of the other line 2L Compared with the conventional second power supply terminal short-circuit direction relay device 110 ₂ , the second circuit breaker 4 ₂ is shut off earlier by the time cooperation time T1 ₂ of the second power supply terminal short-circuit direction relay devices 10 ₂ , 110 _2. can do.

In the above description, the first and second power supply terminal short-circuit direction relay devices 10 ₁ and 10 ₂ are individually configured, but may be configured integrally.

Next, a short-circuit direction relay device according to a second embodiment of the present invention will be described with reference to FIGS.
The short-circuit direction relay device according to the present embodiment is a short-circuit direction relay device installed on the opposite end side of the balanced two-line transmission line. If a short-circuit accident is detected based on the circuit breaker information of the healthy line and the ratio of the accident current flowing from the healthy line to the accident line, the trip signal is generated instantaneously. It is characterized by that.

Therefore, the first opposite-end short-circuit direction relay device 30 ₁ (short-circuit direction relay device according to the second embodiment of the present invention) shown in FIG. 4 is installed on the opposite end side of the other line 2L that is a healthy line. and fourth breaker 4 ₄ has not been blocked, and, upon detecting a short circuit generated in its own line 1L with accident circuits based on the own line accident determination condition shown in (2), the third trip It differs from the conventional first power supply terminal short-circuit direction relay device 120 ₁ shown in FIG. 7 in that it has a function of generating the signal S ₃ instantaneously.
0.86 <| I ₃ −I ₄ | / (I ₃ × 2) <1.18 (2)
Here, the two threshold values (first and second threshold values) are determined according to errors such as current transformer errors (CT errors), relay errors, and line constant errors at the opposite ends. The first threshold value = 0.86 and the second threshold value = 1.18 shown in (2) are used when this error is ± 15%. When the error is ± 10%, the first threshold is “0.9” and the second threshold is “1.12”.

That is, the first opposing end short direction relay device 30 _1, the fourth contact signal S _C4 is cut off at a high level (fourth breaker 4 ₄ of which is input from the fourth breaker 4 ₄ indicates that no.), and, fourth short inputted from the third short-circuit current I ₃ and the fourth current transformer 3 ₄ input from the third current transformer 3 ₃ A value obtained by dividing the absolute value (= | I ₃ −I ₄ |) of the difference from the current I _{4 by} a value (I ₃ × 2) twice the _third short-circuit current I ₃ is the first threshold (0. smaller than the condition greater than 86) the second threshold value (= 1.18), for generating a third trip signal S ₃ instantaneously.
To accomplish this, first opposing end short direction relay device 30 _1, instead of the trip signal generating circuit 140 shown in FIG. 9, includes a trip signal generating circuit 40 shown in FIG.

  As shown in FIG. 5, the trip signal generation circuit 40 includes a relay determination circuit 41, a delay circuit (timer) 42, a logical product circuit 43, and an own line fault determination circuit 45.

Relay determining circuit 41, similarly to the relay determining circuit 141 shown in FIG. 9, the phase relationship of the third short circuit current I ₃ of the magnitude and the second line voltage V ₂ and the third short-circuit current I ₃ On the basis of this, when a short-circuit accident occurring within the instantaneous element operating range of the own line 1L is detected, a high-level third instantaneous element trip signal ST _a3 is output, and the magnitude of the third short-circuit current I ₃ and the second line are output. When a short-circuit fault occurring in the time-limit element operation range of the own line 1L is detected based on the phase relationship between the inter-voltage V ₂ and the third short-circuit current I ₃ , a high-level third time-break output signal is sent to the delay circuit 42. And output to the AND circuit 43.
Similarly to the delay circuit 142 shown in FIG. 9, the delay circuit 42 delays the third time cut-off output signal of the relay determination circuit 41 by the time cooperation time T1 ₃ to generate the third time element trip signal ST _b3 . To do.
The own line fault determination circuit 45 calculates the absolute value (= | I ₃ −I ₄ |) of the difference between the third short-circuit current I ₃ and the fourth short-circuit current I ₄ twice the _third short-circuit current I ₃ . When a value obtained by dividing the value by (I ₃ × 2) is obtained and the obtained value is larger than the first threshold (0.86) and smaller than the second threshold (= 1.18), a high level output is obtained. Output a signal.
The logical product circuit 43 takes the logical product of the third timed interruption output signal of the relay determination circuit 41, the output signal of the own line fault determination circuit 45, and the fourth contact signal S _C4 to generate a third instantaneous trip signal ST. Generate _c3 . Here, we have entered the third time-limit cutoff output signal of the relay determining circuit 41 to the AND circuit 43, the high level when the first opposing end short direction relay device 30 ₁ is not operating This is to prevent the third instantaneous trip signal ST _{c3 from} being erroneously output.

  Next, the operation of the trip signal generation circuit 40 when a short circuit accident occurs in the time limit element operation range of the own line 1L shown in FIG. 4 will be described with reference to FIG.

When a short circuit accident occurs at time t ₀ within the time limit element operation range of the own line 1L, the direction of the short circuit current (first to third short circuit currents I _{1 to} I ₃ ) is the operation direction (internal direction = + direction). The first power supply terminal short-circuit direction relay device 110 ₁ , the second power supply terminal short-circuit direction relay device 110 _2, and the first opposite-end short-circuit direction relay device 30 _{1 that} are the same operate (see FIG. 7).

Relay determining circuit 41 of the trip signal generating circuit 40 to the first opposing end short direction relay device 30 ₁ comprises the own line 1L on the basis of the voltage V ₂ between the second line and the third short-circuit current I ₃ It is determined that a short circuit accident has occurred within the time limit element operation range, and a high level third time limit cutoff output signal is output.
Also, a value obtained by dividing the absolute value (= | I ₃ −I ₄ |) of the difference between the third short-circuit current I ₃ and the fourth short-circuit current I ₄ by a value twice the _third short-circuit current I _3. Is larger than “0.86” and smaller than “1.18”, the own line fault determination circuit 45 determines that a short circuit fault has occurred in the own line 1L and outputs a high-level output signal. .
As a result, the fourth contact signal S _C4 is the at the high level, the third instantaneous trip signal ST _c3 of high level from the AND circuit 43 is output to be input from the fourth breaker 4 _4.

As a result, a third trip signal S ₃ of the high level at time t ₁ that has elapsed since the accident occurrence time t ₀ by the first opposing end short direction relay device 30 ₁ of the relay determination time T _RY (= 50ms) output from the trip signal generating circuit 40 in the third circuit breakers 4 _3.

Thus, the third circuit breakers 4 ₃ is completely cut off at the time t _1a which has elapsed breaker interruption time T _CB (= 50ms) from the time t _1. As a result, the third circuit breaker 4 ₃ is t ₃ −t _1a = T ₁ as compared with the case of the conventional first opposing end short-circuit direction relay device 120 ₁ shown by the broken line in FIG. 6 (see FIG. 10). It can be shut off as early as ₃ (= 400 ms).

When the third circuit breaker 4 ₃ is completely cut off, the fault current flows only from the power source end of the own line 1L toward the fault point, so the first power source short-circuit direction relay device 110 ₁ continues to operate. Thus, the first circuit breaker 4 ₁ is connected to the relay determination time T _RY (= 50 ms), the time limit coordination time T1 ₁ (= 800 ms) and the circuit breaker of the first power supply short-circuit direction relay device 110 ₁ from the accident occurrence time t ₀ . It is completely cut off at time t ₅ when the total time (= 50 ms + 800 ms + 50 ms = 900 ms) of the device cutoff time T _CB (= 50 ms) has elapsed. Accordingly, the first breaker 4 ₁ is completely shut off at the same time t ₅ and the conventional case shown in FIG. 10.

The second opposite-end short-circuit direction relay device 30 ₂ is configured in the same manner as the first opposite-end short-circuit direction relay device 30 ₁ , so that when a short-circuit accident occurs within the time limit element operation range of the other line 2L. Compared with the conventional second opposing end short-circuit direction relay device 120 ₂ , the fourth circuit breaker 4 ₄ is shut off earlier by the time cooperation time T1 ₄ of the second opposing end short-circuit direction relay devices 30 ₂ , 120 _2. can do.

It may be added a second opposing end short direction relay device 30 ₂ quiescent conditions placed on opposite ends of the other line 2L is next line. In this case, an inverter circuit for inverting the polarity of the _fourth trip signal S ₄ output from the second opposing-end short-circuit direction relay device 30 ₂ is added to the trip signal generation circuit 40 shown in FIG. The output signal of the inverter circuit is input to the logical product circuit 43, and the output signal of the relay determination circuit 41, the output signal of the own line fault determination circuit 45, the fourth contact signal S _C4, and the output signal of the inverter circuit What is necessary is just to make the logical product circuit 43 take the logical product.

In the above description, the first and second opposing end short-circuit direction relay devices 30 ₁ and 30 ₂ are individually configured, but may be configured integrally.

  The delay circuit such as the delay circuit 22 shown in FIG. 2 may be configured by a circuit that delays the input signal by a predetermined time. When the input signal is input, the output signal is counted after being counted a predetermined number of times. You may comprise with the timer to output.

It is a diagram for explaining a first power supply terminal short circuit direction relay device 10 ₁ is a short-circuit direction relay device according to a first embodiment of the present invention. First power supply terminal short circuit direction relay device 10 ₁ shown in FIG. 1 is a block diagram showing the configuration of a trip signal generation circuit 20 that comprises. It is a figure for demonstrating operation | movement of the trip signal generation circuit 20 shown in FIG. 2 when the short circuit accident generate | occur | produces in the own line 1L shown in FIG. Is a diagram for explaining a first opposing end short direction relay device 30 ₁ is a short-circuit direction relay device according to a second embodiment of the present invention. The first opposing end short direction relay device 30 ₁ shown in FIG. 4 is a block diagram showing the configuration of a trip signal generation circuit 40 that comprises. FIG. 6 is a diagram for explaining the operation of trip signal generation circuit 40 shown in FIG. 5 when a short circuit accident occurs in its own line 1L shown in FIG. 4. It is a figure for demonstrating that the short circuit direction relay apparatus is used as a back-up protection in a balanced 2 line power transmission line. First power supply terminal short circuit direction relay device 110 ₁ shown in FIG. 7 is a block diagram showing the configuration of a trip signal generation circuit 130 comprises. The first opposing end short direction relay device 120 ₁ shown in FIG. 7 is a block diagram showing the configuration of a trip signal generation circuit 140 comprising. A view for explaining FIG. 7 first power supply terminal short circuit direction relay device 110 ₁ and the first opposing end short direction relay device 120 ₁ of the operation shown in the event of a short circuit accident in the self line 1L occurs is there.

Explanation of symbols

1 power supply 2 _1, 2 ₂ first and second potential transformer 3 ₁ to 3 ₄ first to fourth current transformer 41 _{to 4} first to fourth breaker 10 _1, 10 ₂ , 110 ₁ , 110 ₂ First and second power supply terminal short-circuit direction relay devices 20, 40, 130, 140 Trip signal generation circuits 21, 41, 131, 141 Relay determination circuits 22, 42, 132, 142 Delay circuits 23, 43 AND circuit 25, 45 own line fault judgment circuit 30 ₁ , 30 ₂ , 120 ₁ , 120 ₂ first and second opposite end short-circuit direction relay device 1L own line 2L other line V ₁ first line Voltage V ₂ second line voltage I _{1 to} I ₄ first to fourth short circuit currents S _{1 to} S ₄ first to fourth trip signals ST _{a1 to} ST _a4 first to fourth instantaneous element trips signal ST _b1 ~ST _b4 first to fourth time limiting element trip signal ST _c1 ~ST _c4 first乃Fourth instantaneous trip signals S _C1 to S _C4 first to fourth contact signal T1 ₁ to T1 ₄ Timed coordinated time T _RY relay processing time T _CB breaker breaking time t ₀ ~t _5, t _1a Time

Claims (12)

Installed on the power supply end side of the own line of the balanced two-line power transmission line composed of the own line (1L) and the other line (2L) laid between the power supply end side bus line and the opposite end side opposite end bus line Short-circuit direction relay device (10 ₁ ),
When the occurrence of a short circuit accident in the own line is detected, a trip signal generating circuit (20) for generating a trip signal (S ₁ ) for breaking the own line breaker (4 ₁ ) provided on the power supply end side of the own line )
The trip signal generation circuit has its own line short-circuit current (I ₁ ) flowing from the power supply end of the own line toward the fault point and the other line short-circuit current (I ₂₎ flowing from the power supply end of the other line toward the fault point. ) And a trip signal generating means for instantaneously generating the trip signal when a short-circuit fault is detected based on the ratio of the difference between the short circuit current and the sum of the short circuit current of the other line and the short circuit current of the other line.
A short-circuit direction relay device. It said trip signal generating means, the other line of the next line breaker installed in the power supply end (4 ₂₎ provided that the is not interrupted, detect the short circuit occurs in the self-line on the basis of the ratio The short-circuit direction relay device according to claim 1, wherein the trip signal is generated instantaneously. The trip signal generating means is
A value obtained by dividing the difference between the short-circuit current of the own line and the short-circuit current of the other line by the sum of the short-circuit current of the own line and the short-circuit current of the other line is obtained, and an output signal is output when the obtained value is equal to or greater than a threshold value. Own line accident judgment circuit (25),
A logical product circuit (23) which takes a logical product of the output signal of the own line fault determination circuit and the contact signal (S _C2 ) input from the adjacent circuit breaker;
The short-circuit direction relay device according to claim 2, comprising:   The threshold value is set to "1-X / 100" when an X% section from the power supply end to the opposite end of the own line is a time-reduced protection section. Short-circuit direction relay device.   5. The short-circuit direction relay device according to claim 4, wherein the time-reduced protection section is a section of 80 to 85% from the power supply end to the opposite end of the own line. The other short-circuit direction relay device (10 ₂ ) installed on the power supply end side of the other line has the same configuration as the short-circuit direction relay device and is integrally formed. Item 6. The short-circuit direction relay device according to any one of Items 1 to 5. It is installed on the opposite end side of the own line of the balanced two-line power transmission line composed of the own line (1L) and the other line (2L) laid between the power source end side bus line and the opposite end side opposite end bus line. Short-circuit direction relay device (30 ₁ ),
When the occurrence of a short circuit accident in the own line is detected, a trip signal generating circuit (40) for generating a trip signal (S ₃ ) for breaking the own line breaker (4 ₃ ) provided on the opposite end side of the own line )
The trip signal generating circuit includes trip signal generating means for instantaneously generating the trip signal when a short-circuit accident is detected based on a ratio of a short-circuit current flowing from the other line to the own line on the opposite end side.
A short-circuit direction relay device. The trip signal generation means detects the occurrence of a short-circuit accident on the own line based on the ratio on the condition that the adjacent line breaker (4 ₄ ) installed on the opposite end side of the other line is not cut off. The short-circuit direction relay device according to claim 7, wherein the trip signal is generated instantaneously. The trip signal generating means is
Absolute value of difference between own line short-circuit current (I ₃ ) flowing from the opposite end of the own line toward the fault point and other line short-circuit current (I ₄ ) flowing from the opposite end of the other line toward the fault point Is divided by twice the value of the own line short circuit current, and when the obtained value is larger than the first threshold value and smaller than the second threshold value, the own line fault judgment circuit ( 45)
A logical product circuit (43) that takes a logical product of the output signal of the own line fault determination circuit and the contact signal (S _C4 ) input from the adjacent circuit breaker;
The short-circuit direction relay device according to claim 7, comprising:   The ground fault direction relay according to claim 9, wherein the first and second threshold values are determined according to an error including a current transformer error, a relay error, and a line constant error at the opposite end. apparatus. The trip signal generating means instantaneously generates the trip signal on condition that another short-circuit direction relay device (30 ₂ ) installed on the opposite end side of the other line is inoperative. The short-circuit direction relay device according to claim 7. The other short-circuit direction relay device (30 ₂ ) installed on the opposite end side of the other line has the same configuration as the short-circuit direction relay device and is integrally formed. Item 12. The short-circuit direction relay device according to any one of Items 7 to 11.

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