JP2010166769A - Ground distance relay device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ground distance relay device, capable of markedly shortening ground fault removing time, in a balance two-line power transmission line of a resistance grounding system. <P>SOLUTION: A trip signal generating circuit 20, provided on a first power supply end ground distance relay device 10<SB>1</SB>, includes: an own line Z comparison circuit 22 for outputting an output signal, when a first impedance Z<SB>1</SB>obtained by dividing a bus bar voltage Va by a first line current I<SB>1</SB>becomes a first threshold or lower; a both-line Z comparison circuit 23 for outputting an output signal, when a both line impedance Z<SB>a</SB>obtained by dividing the bus bar voltage Va by the sum of first and second line currents I<SB>1</SB>, I<SB>2</SB>becomes a second threshold or lower ; an inverter circuit 26 for inverting the polarity of the output signal of own line Z comparison circuit 22; a fourth logical product circuit 24<SB>4</SB>for calculating the logical product between the output signal of the both-line Z comparison circuit 23 and the output signal of the inverter circuit 26; and a delay circuit 27 for delaying the time axis of the output signal of the fourth logical product circuit 24<SB>4</SB>by the delay time DL. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a ground fault distance relay device, and more particularly, to a ground fault distance relay device suitable for installation on a power source end side and an opposite end side of a balanced two-line power transmission line.

Generally, a ground fault direction relay device (DG) used for protection in the event of a ground fault in a power system is an electric quantity (zero phase voltage) of its own line (a transmission line in which the ground fault direction relay device is installed). V ₀ and _zero- phase current I ₀ ) are determined on the basis of the magnitude and direction of the ground fault and are installed on the transmission line behind the opposite end (non-power source end) to determine the fault section. Time-dependent coordination (stacking of 0.4 s to 0.5 s) is taken with other ground fault direction relay devices.
Therefore, in the ground fault direction relay device installed at the power supply end side, as will be described below, the accident removal time becomes longer, so the ground fault direction relay device is used as a back-up protection in the balanced two-line transmission line. In addition, the accident removal time is shortened by installing a separate main protection relay device that operates instantaneously due to a ground fault 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. Ground fault direction relay device (hereinafter referred to as “first and second power source ground fault direction relay devices 110 ₁ , 110 ₂ ”) on the power supply end side (bus side) of the line 2L ”. Are installed, and the ground fault direction relay device (hereinafter referred to as “first and second opposite end ground fault direction relay devices” is also provided on the opposite end side (opposite side of the bus line) of the own line 1L and the other line 2L. 120 ₁ , 120 ₂ ”) are installed.

The first power terminal ground fault direction relay device 110 ₁ is connected to the power line zero-phase voltage V _0a input from the first grounded-type instrument transformer (EVT) 102 ₁ provided on the bus and the own line 1L. When the occurrence of a ground fault in the own line 1L is detected based on the first zero-phase current I ₀₁ inputted from the first zero-phase current transformer (ZCT) 103 ₁ installed on the power supply end side, A first trip signal S ₁ for breaking the first circuit breaker 4 ₁ installed on the 1 L power supply end side is generated.
The second power-source ground fault direction relay device 110 ₂ includes a power-source zero-phase voltage V _0a input from the first grounded-type instrument transformer 102 ₁ and a second zero-phase installed on the other line 2L. Upon detection of the ground fault occurs in the other line 2L based on the second zero-phase current I ₀₂ inputted from the current transformer 103 _2, the second circuit breaker 4 disposed on the power supply terminal side of the other line 2L _{A second} trip signal S ₂ for interrupting ₂ is generated.

The first opposite-end ground fault direction relay device 120 ₁ is input from a _second grounded instrument transformer 102 ₂ provided on the opposite-end bus (hereinafter referred to as “opposite-end bus”). in its own line 1L on the basis of the third zero-phase current I ₀₃ inputted from the third zero-phase current transformer 103 ₃ installed on the opposite end of that opposite end zero-phase voltage V _0b and self line 1L When the occurrence of the ground fault is detected, a third trip signal S ₃ for breaking the third circuit breaker 4 ₃ installed on the opposite end side of the own line 1L is generated.
The second opposite-end ground fault direction relay device 120 ₂ is installed on the opposite end side of the opposite-end zero-phase voltage V _0b input from the second grounded-type instrument transformer 102 ₂ and the other line 2L. When the occurrence of a ground fault in the other line 2L is detected on the basis of the fourth zero-phase current I ₀₄ input from the fourth zero-phase current transformer 1034, a _fourth installed on the opposite end side of the other line 2L. generating a breaker 4 ₄ 4 trip signal S ₄ of for blocking the.

The first power source ground fault 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, first to third delay circuits (timers) 132 _{1 to} 132 ₃ , an AND circuit 133, and an OR circuit 134.

Relay determining circuit 131, a ground fault generated in the own line 1L based on the phase relationship between the first zero-phase current I ₀₁ of the size and power terminal zero-phase voltage V _0a and the first zero-phase current I ₀₁ When detected, a high level output signal is output.
The first delay circuit 132 ₁ delays the first OVG output signal S _OVG1 inputted from the first ground fault over-voltage relay device (OVG) 5 ₁ Only first timed coordination time T1 _1. Here, the first ground fault over-voltage relay device 5 _1, the high level when the magnitude of the first power supply terminal zero-phase voltage V _0a inputted from earth type potential transformer 2 ₁ becomes equal to or higher than set point The first OVG output signal S _OVG1 is output.
AND circuit 133 takes a logical product of the output signal and the first OVG output signal S _OVG1 by the first delay circuit 132 ₁ is delayed first by timed coordination time T1 the _first relay determining circuit 131.
The second delay circuit 132 ₂ delays the output signal of the AND circuit 133 by the second time cooperation time T2 ₁ . The second timed coordination time T2 ₁ is set for the timed coordination with the own line 1L other ground direction relay apparatus installed at opposite ends behind the transmission line (not shown). The first power supply terminal operation timed T _DG1 ground fault direction relay device 110 ₁ is the total time of the timed coordination time T2 ₁ of the first timed coordination time T1 ₁ and the _{2 (T DG1 = T1 1 +} T2 1 )
The third delay circuit 132 ₃ delays the first OVG output signal S _OVG1 inputted from the first ground fault over-voltage relay device 5 ₁ by a third timed coordination time T3 _1. Here, the third timed coordination time T3 ₁ is set for the protection of the back-end of the first power source ground fault direction relay device 110 ₁ .
The logical sum circuit 134 takes a logical sum of the output signal of the _second delay circuit 132 _{2 and} the output signal of the third delay circuit 132 ₃ .

Second power supply ground fault 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 opposed end ground fault direction relay device 120 ₁ includes a trip signal generating 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, first to third delay circuits (timers) 142 _{1 to} 142 ₃ , an AND circuit 143, and an OR circuit 144.

Relay determining circuit 141, a ground fault generated in the own line 1L based on the phase relation of the third zero-phase current magnitude and opposite end zero-phase voltage of the I ₀₃ V _0b and third zero-phase current I ₀₃ When detected, a high level output signal is output.
The first delay circuit 142 ₁ delays the second OVG output signal S _OVG2 inputted from the second ground fault over-voltage relay device 5 ₂ by a first timed coordination time T1 _3. Here, the second ground fault over-voltage relay device 5 _2, the high level when the magnitude of the second opposing end zero-phase voltage V _0b inputted from earth type potential transformer 102 ₂ becomes higher setpoint The second OVG output signal S _OVG2 is output.
The logical product circuit 143 calculates the logical product of the output signal of the relay determination circuit 141 and the second OVG output signal S _OVG2 delayed by the first time limit coordination time T1 ₃ by the first delay circuit 142 ₁ .
The second delay circuit 142 ₂ delays the output signal of the AND circuit 143 by the second time cooperation time T2 ₃ . Here, the second time cooperation time T2 ₃ is set for time cooperation with the _first power source ground fault direction relay device 110 ₁ and is set in the second delay circuit 132 ₂ shown in FIG. Is set to be smaller than the second timed coordination time T2 ₁ (T2 ₃ <T2 ₁ ). The operation time limit T _DG3 of the first opposing ground fault direction relay device 120 ₁ is the total time of the first time cooperation time T1 ₃ and the second time cooperation time T2 ₃ (T _DG3 = T1 ₃ + T2 ₃ )
The third delay circuit 142 ₃ delays the second OVG output signal S _OVG2 inputted from the second ground fault over-voltage relay device 5 ₂ by a third timed coordination time T3 _3. Here, the third timed coordination time T3 ₃ is set for the first backup protection opposing end ground fault direction relay device 120 _1.
OR circuit 144 takes the logical sum of the second delay circuit 142 and _second output signal and the third delay circuit 142 ₃ of the output signal.

The second opposite-end ground fault 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.

When the first self line 1L ground fault at a time t ₀ shown in FIG. 10 at the opposite end of which is a power supply terminal ground direction relay device 110 ₁ of the guard interval occurs, the first to third zero The first power source ground fault direction relay device 110 ₁ , the second power source ground fault direction relay device 110 _2, and the first phase currents I _{01 to} I ₀₃ whose direction is the same as the operation direction (internal direction). opposite end ground fault direction relay device 120 ₁ is operated.

Since the operation time limit T _DG3 of the first opposing ground fault direction relay device 120 ₁ is shorter than the operation time _limits T _DG1 and T _DG2 of the first and second power source ground fault direction relay devices 110 ₁ and 110 _2. First, the first opposing ground fault direction relay device 120 ₁ operates to interrupt the third circuit breaker 4 ₃ installed on the opposing end side of the own line 1L. At this time, the third circuit breakers 4 _3, as shown in FIG. 10 (b), the accident occurrence time t ₀ from the first opposing end ground fault direction relay device 120 _first relay determination time T _RY and operation timed Although it is interrupted by the _third trip signal S ₃ output from the first opposing ground fault direction relay device 120 ₁ at time t ₂ when only T _{DG3 has} elapsed, the third circuit breaker 4 ₃ is completely interrupted. which is given to, the time t ₃ when has elapsed breaker interruption time T _CB from time t _2.

When the third circuit breaker 4 ₃ is completely cut off at the time t ₃ , the fault current flows only from the power supply end of the own line 1L toward the fault point (that is, only the first zero-phase current I ₀₁ is _generated. Therefore, only the first power supply ground fault direction relay device 110 ₁ continues to operate and shuts off the first circuit breaker 4 ₁ installed on the power supply end side of the own line 1L. At this time, the first breaker 4 _1, as shown in FIG. 10 (a), the accident occurrence time t ₀ from the first power supply terminal ground direction relay device 110 _first relay determination time T _RY and operation timed Although it is interrupted by the _first trip signal S ₁ output from the first power source ground fault direction relay device 110 ₁ at time t ₅ when only T _{DG1 has} elapsed, the first circuit breaker 4 ₁ is completely interrupted. It is time t ₆ when the circuit breaker breaking time T _{CB has} elapsed from time t ₅ .

Further, when the first power supply terminal time t ₀ to ground fault shown in Figure 11 at the power supply terminal side of the own line 1L, which is a ground fault direction relay device 110 ₁ of the guard interval occurs, the first zero-phase The first power supply ground fault direction relay device 110 _{1 in} which the direction of the current I ₀₁ is the same as the operation direction (internal direction) operates.

As a result, the first power source ground fault direction relay device 110 ₁ interrupts the first circuit breaker 4 ₁ installed on the power source side of the own line 1L. At this time, the first breaker 4 _1, 11 (a), the accident occurrence time t ₀ from the first power supply terminal ground direction relay device 110 _first relay determination time T _RY and operation timed Although it is interrupted by the _first trip signal S ₁ output from the first power source ground fault direction relay device 110 ₁ at time t ₅ when only T _{DG1 has} elapsed, the first circuit breaker 4 ₁ is completely interrupted. It is time t ₆ when the circuit breaker breaking time T _{CB has} elapsed from time t ₅ .
Also, the size of the opposite end zero-phase voltage V _0b becomes higher setpoint This ground fault, the second ground fault over-voltage relay device 5 ₂ outputs second OVG output signal S _OVG2 high level Therefore, the output signal of the first delay circuit 142 ₁ of the trip signal generation circuit 140 (see FIG. 9) included in the first opposing ground fault direction relay device 120 ₁ is the first time limit from the accident occurrence time t ₀ . at the time t ₂ has passed only emphasized time T1 ₃ consisting of a low level to a high level. Thereafter, the first opposite-end ground-fault relay device 120 ₁ waits for the output of the relay determination circuit 141.
Similarly, when the magnitude of the power supply terminal zero-phase voltage V _0a is more setpoint This ground fault, the first ground fault over-voltage relay device 5 ₁ outputs the first OVG output signal S _OVG1 high level Therefore, the output signal of the first delay circuit 132 ₁ of the trip signal generation circuit 130 (see FIG. 8) included in the second power supply ground fault direction relay device 110 ₂ is the first from the accident occurrence time t ₀ . from the low to high level at time t ₄ when the elapsed time period emphasized time T1 _2. Thereafter, the second power source ground fault direction relay device 110 ₂ waits for the output of the relay determination circuit 131.

When the first circuit breaker 4 ₁ is completely cut off at time t ₆ , the second and third zero-phase currents I ₀₂ and I ₀₃ become large, so that the second power source ground fault direction relay 110 ₂ and The first opposed end ground fault direction relay 120 ₁ operates together.
As a result, in the second power source ground fault direction relay device 110 ₂ , the second trip signal S ₂ is second interrupted at the time t ₇ when the second time cooperation time T _{2 2 has} elapsed from the time t ₆ . It is output to the vessel 4 _2. Also, in the first opposing ground fault direction relay device 120 ₁ , the third trip signal S ₃ is transmitted to the third circuit breaker at the time t ₇ when the second time cooperation time T 2 _{3 has} elapsed from the time t ₆ . 4 is output to ₃ .
As a result, as shown in FIGS. 11B and 11C, the second and third circuit breakers 4 ₂ and 4 ₃ are simultaneously connected at time t ₈ when the circuit breaker breaking time T _{CB has} elapsed from time t _7. Completely blocked.

Patent Document 1 listed below ensures accident interruption selectivity and enables high-speed interruption in a protective relay device having a back-end protection means that protects a three-terminal transmission line by a distance relay method with a stage limit. Therefore, the means for transmitting the operating condition of the second stage relay for detecting the accident in the opposite bus direction including the opposite bus, the means for receiving the transfer signal from the opposite end, and the operation of the protection relay at its own end are received. A protective relay device is disclosed that includes a means for outputting a break command to a self-breaker provided that the transfer signal continues for a predetermined time or longer.
JP-A-5-76134

However, the ground fault protection relay system that combines the above-described ground fault direction relay device and the ground fault overvoltage relay device has the following problems.
(1) when the ground fault occurs in the own line 1L, the first breaker 4 ₁ accident occurrence time t ₀ from the first power supply terminal ground direction relay device 110 _first relay determination time T _RY, Since it is cut off at time t ₆ when the total time of the operation time limit T _DG1 and the circuit breaker breaking time T _CB has elapsed (see FIG. 10 (a) and FIG. 11 (a)), it takes time to eliminate the ground fault. In other words, there is a problem of adversely affecting the equipment.
(2) When a ground fault occurs near the power supply end of the own line 1L, the second and third circuit breakers 4 ₂ and 4 ₃ are simultaneously disconnected at time t ₈ (FIG. 11B). , (C)), there is a problem that the other line 2L is unnecessarily blocked.

  In the protection relay device described in Patent Document 1, the accident removal time can be shortened when a ground fault occurs in the second protection section of the own line 1L, but the transfer signal from the opposite terminal is continuously received. Therefore, there is a problem that a transmission path for this transfer signal is necessary because the circuit breaker of the own terminal is cut off.

  An object of the present invention is to provide a ground fault distance relay device that can significantly shorten the ground fault accident elimination time in a resistance grounded balanced two-line transmission line.

The ground fault distance relay device according to the present invention is a balanced two-line power transmission line composed of a self-line (1L) and another line (2L) laid between a power source end-side bus and a counter end-side counter end bus. A ground fault distance relay device (10 ₁ ) installed on the power supply end side of the own line, and detecting a ground fault occurrence on 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 based on changes in its own line impedance and both line impedances. It is characterized by comprising trip signal generating means for instantly generating the trip signal when it is detected that the opposite end circuit breaker (4 ₃ ) installed on the opposite end side of the own line is cut off.
Here, the own line impedance (Z ₁ ) calculated by the trip signal generating means by dividing the bus voltage (Va) by the own line current (I ₁ ) flowing through the power supply end of the own line is a first threshold value. (Th _1a ) The self-line impedance comparison circuit (22) that outputs an output signal when it becomes less than or equal to (Th _1a ), the self-line voltage and the other line current (I ₂ ) flowing through the power line end side of the other line. When the two-line impedance (Z _a ) calculated by dividing by the sum of the two becomes equal to or less than the second threshold value (Th _2a ), the two-line impedance comparison circuit (23) that outputs an output signal, the inverter circuit (26) for inverting the polarity, the first aND circuit taking the logical product of the output signal of the output signals of both line impedance comparator circuit and said inverter circuit (24 ₄₎ An extension circuit (27) 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 a second logical product circuit (24 ₅ ) that takes a logical product of.
The extension time may be longer than a total time of a relay determination time (T _RY ) of the ground fault distance relay device and a circuit breaker cutoff time (T _CB ) of the own circuit breaker.
On the condition that the trip line generating means is not interrupted by the adjacent line breaker (4 ₂ ) installed on the power supply end side of the other line, the trip signal generating means The trip signal may be generated instantaneously when it is detected that the end circuit breaker has been cut off.
The other ground fault distance relay device (10 ₂ ) installed on the power supply end side of the other line may have the same configuration as the ground fault distance relay device and may be integrally configured.
In addition, the ground fault distance 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 ground fault distance relay device (30 ₁ ) installed on the opposite end side of the own line of the electric wire and provided on the opposite end side of the own line when the occurrence of a ground fault in the own line is detected A trip signal generating circuit (40; 40a) for generating a trip signal (S ₃ ) for interrupting the own circuit breaker (4 ₃ ), the trip signal generating circuit based on a change in the own line impedance; It is characterized by comprising trip signal generating means for instantaneously generating the trip signal when it is detected that the power supply circuit breaker (4 ₁ ) installed on the power supply terminal side of the own line is cut off.
Here, the own line impedance (Z ₃ ) calculated by the trip signal generating means by dividing the opposite end bus voltage (Vb) by the own line current (I ₃ ) flowing on the opposite end side of the own line is first. A self-line impedance comparison circuit (42) that outputs an output signal when the value is equal to or less than a threshold value (Th _1b ), and the other-line current ( Both line impedance comparison circuit (43) that outputs an output signal when both line impedances (Z _b ) calculated by dividing by the sum of I ₄ ) are equal to or lower than the second threshold (Th _2b ), and the self line impedance comparison A logical product circuit (44 ₄ ) that takes a logical product of the output signal of the circuit and the output signal of the two-line impedance comparison circuit may be provided.
The own line impedance (Z ₃ ) calculated by the trip signal generating means by dividing the opposite end bus voltage (Vb) by the own line current (I ₃ ) flowing on the opposite end side of the own line is a first threshold ( Th _1b ), the self-line impedance comparison circuit (42) for outputting the output signal when it is equal to or less, the inverter circuit (51) for inverting the polarity of the output signal of the self-line impedance comparison circuit, and the opposite end bus A first product that takes the logical product of the output signal (S _OVG ) of the ground fault overvoltage relay device or the output signal of the ground fault over current relay device installed on the opposite end side of the own line and the output signal of the inverter circuit An AND circuit (52), an extension circuit (53) that extends the time axis of the output signal of the first AND circuit by an extension time (DL), and an output signal of the own-line impedance comparison circuit; The extension And a second logical product circuit (44 ₄ ) that performs a logical product with the output signal of the circuit.
The extension time may be longer than a total time of a relay determination time (T _RY ) of the ground fault distance relay device and a circuit breaker cutoff time (T _CB ) of the own circuit breaker.
On the condition that the trip line generating means is not interrupted by the adjacent line breaker (4 ₄ ) installed on the opposite end side of the other line, the power supply end breaker The trip signal may be generated instantaneously when it is detected that it has been shut off.
The other ground fault distance relay device (30 ₂ ) installed on the opposite end side of the other line may have the same configuration as that of the ground fault distance relay device and may be integrally configured.

The ground fault distance relay device of the present invention has the following effects.
(1) Since the trip signal can be generated instantly when the opposite circuit breaker on its own line is interrupted, ground faults that occur near the power supply end and the opposite end of the balanced two lines of the resistance grounding system are eliminated. Time can be significantly reduced.
(2) Since a trip signal is generated instantaneously when it is detected that the opposite circuit breaker is cut off due to changes in its own line impedance and / or both line impedances, there is no need to provide a transmission path for the transfer signal from the opposite end. .
(3) Since the ground fault accident continuation time is also greatly shortened, adverse effects on the equipment 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.

  The above object is realized by instantaneously generating a trip signal when it is detected that the circuit breaker installed on the opposite side of the own line is cut off based on changes in the own line impedance and / or both line impedances.

Hereinafter, embodiments of the ground fault distance relay device of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the first and second power source ground fault distance relay devices 10 ₁ and 10 ₂ , which are ground fault distance relay devices according to an embodiment of the present invention, have their own line 1L and other line 2L. It is installed on the power supply end side. Further, the first and second opposing end ground fault distance relay devices 30 ₁ and 30 ₂ , which are ground fault distance relay devices according to one embodiment of the present invention, are provided on the opposite end sides of the own line 1L and the other line 2L. Each is installed.

First power supply terminal ground fault distance relay apparatus 10 ₁ includes a first variable that is provided to the power supply terminal side of the bus voltage Va and the own line 1L inputted from the first transformer 2 ₁ provided in bus A first impedance Z ₁ (Z ₁ = Va / I ₁ ) of the own line 1L is calculated based on the first line current I ₁ input from the flow device 3 ₁ , and the calculated first impedance Z ₁ is obtained. Based on this, when the occurrence of a ground fault in the own line 1L is detected, a first trip signal S ₁ for breaking the _first circuit breaker 41 provided on the power supply end side of the own line 1L is generated. Here, the first power supply terminal ground fault distance relay apparatus 10 ₁ includes a first guard interval of the self line 1L based on the first impedance Z ₁ (first power supply terminal ground fault distance relay apparatus 10 ₁ of a 1-stage operation zone A1, which is 70% of the section to the opposite end from the power source terminal of the own line 1L. Upon detecting the ground fault occurs in), the first trip signals S ₁ instantaneous (first occurs timed coordination time GT1 ₁ = 0), the first impedance Z second guard interval of the self line 1L based on ₁ (first two-stage operation area of the power supply terminal ground fault distance relay apparatus 10 ₁ A2 and is a 140% of the section to the opposite end from the power source terminal of the own line 1L.) Upon detecting a ground fault occurs in the first trip signals S ₁ second timed coordination time GT2 ₁ timed coordination It occurs with.
The first power supply terminal ground fault distance relay apparatus 10 ₁ is placed on the opposite end of its own line 1L based on a change of the own line impedance (first impedance Z ₁₎ and later to both line impedance Z _a When it is detected that the third circuit breaker 4 ₃ is cut off, the first trip signal S ₁ is instantaneously generated.

Therefore, the first power supply terminal ground fault distance relay apparatus 10 ₁ comprises a trip signal generating circuit 20 shown in FIG.

As shown in FIG. 2, the trip signal generation circuit 20 includes an operating range determination circuit 21, an own line impedance comparison circuit 22 (hereinafter referred to as “own line Z comparison circuit 22”), and a both line impedance comparison circuit 23. (Hereinafter, referred to as “both line Z comparison circuit 23”), first to sixth AND circuits 24 _{1 to} 24 ₆ , a delay circuit (timer) 25, an inverter circuit 26, and an extension circuit 27 and an OR circuit 28.

The operating area determination 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 . based determines a first operation range of the power supply terminal ground fault distance relay apparatus 10 _1.
That is, the operating area determination circuit 21 determines that the calculated first impedance Z ₁ is the maximum impedance (hereinafter referred to as “first maximum impedance Z”) of the first stage operating area A ₁ of the first power source ground fault distance relay device 10 _1. It referred _1max ".) If it is less, it is determined that" the first operation zone of the power supply terminal ground fault distance relay apparatus 10 ₁ is 1-stage operation zone A1 ', first and second high-level The determination result output signals VD ₁ and VD ₂ are output. In addition, the operating range determination circuit 21 determines that the calculated first impedance Z ₁ is larger than the first maximum impedance Z _{1max and} the maximum impedance of the two-stage operating range A2 of the first power source ground fault distance relay device 10 _1. (hereinafter, "second maximum impedance Z _2max" referred.) was determined by mass or less, "the first operation zone of the power supply terminal ground fault distance relay apparatus 10 ₁ is a two-stage operation region A2" Then, the high-level second determination result output signal VD ₂ is output.

The first logical product circuit 24 ₁ takes the logical product of the first and second determination result output signals VD ₁ and VD ₂ input from the operation region determination circuit 21.
Second AND circuit 24 ₂ takes the logical product of the FD relay output signal S _FD and the first AND circuit 24 ₁ of the output signal from the relay device for fail-safe (not shown).
The third logical product circuit 24 ₃ takes the logical product of the second determination result output signal VD ₂ input from the operation region determination circuit 21 and the FD relay output signal _SFD .
The delay circuit 25 delays the output signal of the _third AND circuit 24 ₃ by the second time cooperation time GT2 ₁ .

The own line Z comparison circuit 22 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 23, calculates the bus voltage Va of the first and second line current I _1, the two divided by the sum of I ₂ line impedance _{Z a (Z a = Va /} (I 1 + I 2)) After the both line impedance Z _a calculated and outputs a second becomes less than the threshold value Th _2a of the output signal of the high level.
The inverter circuit 26 inverts the polarity of the output signal of the own line Z comparison circuit 22.
The fourth logical product circuit 24 ₄ takes the logical product of the output signal of the inverter circuit 26 and the output signal of the two-line Z comparison circuit 23.
The extending circuit 27 extends the time axis of the output signal of the _fourth AND circuit 244 and extends it by the time DL. Here, the spreading time DL is greater than the total time of the first power supply terminal ground fault distance relay apparatus 10 ₁ in the relay determination time T _RY and the first breaker 4 ₁ of the circuit breaker breaking time T _CB Set to the value (DL> T _RY + T _CB ).
The fifth AND circuit 24 ₅ takes a logical product of the output signal of the _fourth AND circuit 24 ₄ whose time axis is expanded by the extending circuit 27 and the output signal of the own-line Z comparison circuit 22.
The sixth AND circuit 24 ₆ takes the logical product of the second contact signal S _C2 input from the second circuit breaker 4 ₂ and the fifth AND circuit 24 ₅ of the output signal of the.
OR circuit 28 takes the logical sum of the output signals of the AND circuit 24 ₆ sixth of the second AND circuit 24 and _second output signal and the delay circuit 25.

A second power supply terminal ground fault distance relay apparatus 10 ₂ is configured similarly to the first power supply terminal ground fault distance relay apparatus 10 ₁ described above.

The first opposing end ground fault distance relay apparatus 30 ₁ provided on the opposite end side of the opposite ends bus voltage Vb and the own line 1L inputted from the second transformer 2 ₂ provided at opposite ends bus Based on the third line current I ₃ input from the third current transformer 3 ₃ , the third impedance Z ₃ (Z ₃ = Vb / I ₃ ) of the own line 1L is calculated, and the calculated third When the occurrence of a ground fault in the own line 1L is detected based on the impedance Z ₃ , a third trip signal S ₃ for breaking the third circuit breaker 4 ₃ provided on the opposite end side of the own line 1L is generated. To do. Here, the first opposite-end ground-fault relay device 30 ₁ is connected to the third protection section (first opposite-end ground-fault relay device 30 ₁ of the own line 1L based on the third impedance Z _3. of a 1-stage operation zone A1, upon detecting a ground fault occurs in 70% of the interval.) from the opposite end of its own line 1L to the power supply terminal, a third trip signal S ₃ instant (first occurs timed coordination time GT1 ₃ = 0), the third impedance Z ₃ on the basis of the fourth guard interval of the self line 1L (first two-stage operation region of the opposite end ground fault distance relay apparatus 30 ₁ A2 and is a 140% of the section from the opposite end of its own line 1L to the power supply terminal.) Upon detecting the ground fault occurs in the third trip signal S ₃ second timed coordination time GT2 ₃ timed coordination It occurs with. Here, the second time cooperation time GT2 ₃ is set to a value smaller than the second time cooperation time GT2 _{1 of} the first power supply ground fault distance relay device 10 ₁ described above (GT2 ₃ <GT2 ₁ ).
In addition, the first opposing ground fault distance relay device 30 ₁ includes the first circuit breaker 4 installed on the power supply end side of the own line 1L based on the change of the third impedance Z ₃ (own line impedance). When _one is detected to be blocked, to generate a third trip signal S ₃ instantaneously.

Therefore, the first opposing end ground fault distance relay apparatus 30 ₁ comprises a trip signal generating circuit 40 shown in FIG.

As shown in FIG. 3, the trip signal generation circuit 40 includes an operating range determination circuit 41, an own line impedance comparison circuit 42 (hereinafter referred to as “own line Z comparison circuit 42”), and a both line impedance comparison circuit 43. comprising (hereinafter, referred to as "two lines Z comparator circuit 43 '.), a logical product circuit 44 ₁ to 44 ₅ of the first to fifth, a delay circuit (timer) 45, and an oR circuit 48.

The operating area determination circuit 41 calculates the third impedance Z ₃ (Z ₃ = Vb / I ₃ ) by dividing the opposed end bus voltage Vb by the third line current I ₃ , and then calculates the calculated third impedance Z. based on ₃ determines a first operation region of the opposite end ground fault distance relay apparatus 30 _1.
That is, the operation area determination circuit 41 outputs the calculated third largest impedance of the impedance Z ₃ is the first opposed end ground fault distance relay apparatus 30 ₁ in one stage operation zone A1 (hereinafter, "third maximum impedance Z It referred _3max ".) If it is less, it is determined that" the first operation zone of the opposite end ground fault distance relay apparatus 30 ₁ is 1-stage operation zone A1 ', first and second high-level The determination result output signals VD ₁ and VD ₂ are output. The operation area determination circuit 41, the maximum impedance of the third impedance Z ₃ is a third up impedance Z first opposing end ground fault distance relay device larger than _3max 30 ₁ of a two-stage operation area A2 calculated (hereinafter, referred to as. "fourth maximum impedance Z _4Max of") was determined by mass or less, "the first operation zone of the opposite end ground fault distance relay apparatus 30 ₁ is a two-stage operation region A2" Then, the high-level second determination result output signal VD ₂ is output.

The first logical product circuit 44 ₁ takes the logical product of the first and second determination result output signals VD ₁ and VD ₂ input from the operation region determination circuit 41.
Second AND circuit 44 ₂ takes the logical product of the FD relay output signal S _FD 'and the first AND circuit 44 ₁ of the output signal from the other relay device for fail-safe (not shown) .
The third logical product circuit 44 ₃ takes the logical product of the second determination result output signal VD ₂ input from the operation region determination circuit 41 and the FD relay output signal S _FD ′.
The delay circuit 42 delays the output signal of the _third AND circuit 44 ₃ by the second time cooperation time GT2 ₃ .

The own line Z comparison circuit 42 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.
The both-line Z comparison circuit 43 divides the opposite-end bus voltage Vb by the sum of the third and fourth line currents I ₃ and I ₄ to divide both line impedances Z _b (Z _b = Vb / (I ₃ + I ₄ )) After calculating the both line impedance Z _b calculated outputs the second becomes less than the threshold value Th _2b of the output signal of the high level.
The fourth logical product circuit 44 ₄ takes the logical product of the output signal of the own line Z comparison circuit 42 and the output signal of both the line Z comparison circuits 43.
Fifth AND circuit 44 _5, a logical product of the fourth fourth contact signal S _C4 to the fourth AND circuit 44 ₄ of the output signal input from the breaker 4 _4.
OR circuit 48 takes the logical sum of the output signal and the fifth output signal of the AND circuit 44 ₅ of the second AND circuit 44 and _second output signal and the delay circuit 45.

The second opposing end ground fault distance relay device 30 ₂ is configured in the same manner as the first opposing end ground fault distance relay device 30 ₁ described above.

Next, the first power supply terminal ground fault distance relay apparatus 10 ₁ and the first operation of the opposite end ground fault distance relay apparatus 30 ₁ in the case of earth fault at the opposite end near to the own line 1L is generated, This will be described with reference to FIG.

When a ground fault occurs at time t ₀ near the opposite end of the own line 1L, the first power supply terminal in which the directions of the _{first to third} line currents I _{1 to} I ₃ are the same as the operation direction (internal direction) The ground fault distance relay device 10 ₁ , the second power source ground fault distance relay device 10 _2, and the first opposite end ground fault distance relay device 30 ₁ operate.

The operating area determination circuit 41 of the trip signal generation circuit 40 (see FIG. 3) included in the first opposed-end ground-fault relay device 30 ₁ divides the opposed-end bus voltage Vb by the third line current I _3. After calculating the third impedance Z ₃ (Z ₃ = Vb / I ₃ ), based on the calculated third impedance Z ₃ , “the operating range of the first opposing ground fault distance relay device 30 ₁ is 1. It is determined that it is the stage operation area A1, ”and the first and second determination result output signals VD ₁ and VD ₂ of high level are output.
As a result, the output signal of the _first AND circuit 44 ₁ changes from the low level to the high level. Therefore, when the FD relay output signal S _FD ′ is at the high level, the output signal of the _second AND circuit 442 becomes the low level. To high level. As a result, since the output signal of the OR circuit 48 changes from the low level to the high level, the third trip signal S ₃ is output from the trip signal generation circuit 40 to the third circuit breaker 4 ₃ .
As shown in FIG. 4B, the third trip signal S ₃ is a time when the relay determination time T _RY in the first opposing ground fault distance relay device 30 ₁ has elapsed since the accident occurrence time t ₀ . The signal is output from the trip signal generation circuit 40 at t ₁ .
Accordingly, the third breaker 4 ₃ of, and FIG. 4 (b) in as shown by the solid line, the accident occurrence time t ₀ from the relay determination time T _RY and breaker interrupting the total time of the time T _CB (e.g., 50 ms) It is completely cut off at time t _{1a that} has passed. As a result, the conventional case shown by the broken line in FIG. 4 (b) than in (FIG. 10 (b) refer), the third circuit breakers 4 ₃ a second opposing end ground fault direction relay device 120 ₁ of It can be shut off quickly by the operation time limit T _DG3 (= 500 ms).

In the first power supply ground fault distance relay device 10 ₁ , the operating range determination circuit 21 of the trip signal generation circuit 20 (see FIG. 2) divides the bus voltage Va by the first line current I ₁ to obtain the first After calculating the impedance _{Z 1 (Z 1 = Va /} I 1), the first based on the impedance Z ₁ "first power supply terminal ground fault distance relay device 10 operation range of ₁ bunk operation area calculated A2 ”is determined, and the second determination result output signal VD ₂ having a high level is output. As a result, when the FD relay output signal _SFD is at a high level, the output signal of the _third AND circuit 24 ₃ changes from a low level to a high level, but the output signal of the _third AND circuit 24 ₃ is a delay circuit. 25, the output signal of the delay circuit 25 remains at the low level at the time t _1a because the delay time is delayed by the second time cooperation time GT2 ₁ .
Further, after the occurrence of the ground fault, 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 output signal of the own line Z comparison circuit 42 is Since it remains at the low level, the output signal of the _fifth AND circuit 245 remains at the low level.
As a result, the first trip signal S ₁ output from the trip signal generation circuit 20 remains at a low level.
After the occurrence of the ground fault, both line impedances (that is, both line impedances Z _a ) viewed from the power supply end of the own line 1L are equal to or lower than the second threshold Th _2a. Changes from low level to high level. As a result, the output signal of the own line Z comparison circuit 42 whose polarity is inverted to the high level by the inverter circuit 26 and the high level output signal of both the line Z comparison circuits 43 are input to the fourth AND circuit 24 _4. Therefore, the output signal of the _fourth AND circuit 244 is changed from the low level to the high level. The high-level output signal of the _fourth AND circuit 24 ₄ is extended by the extension circuit 27 for the time DL by extending the time axis.

A second power supply terminal ground fault distance relay device 10 ₂ operates similarly to the first power supply terminal ground fault distance relay apparatus 10 ₁ described above.

When the third circuit breaker 4 ₃ is completely cut off at the time t _1a , the fault current flows only from the power supply end of the own line 1L toward the fault point (that is, the first line current I ₁ becomes large). Therefore, since the impedance viewed from the power supply terminal of the own line 1L (that is, the first impedance Z ₁ ) is equal to or less than the first threshold Th _1a , the first power supply ground fault distance relay device 10 ₁ is provided. The output signal of the own line Z comparison circuit 22 of the trip signal generation circuit 20 that changes from low level to high level. As a result, the output signal of the stretching circuit 27 because it remains as the high level, the output signal of the fifth AND circuit 24 ₅ 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 _sixth AND circuit 246 is changed from a low level to a high level. Become a level. As a result, the output signal of the OR circuit 28 is changed from the low level to the high level, the first trip signal S ₁ is output from the trip signal generating circuit 20 to the first breaker 4 _1.
The first trip signals S _1, as shown in FIG. 4 (a), the time t _1b from the time t _1a has elapsed the relay determination time T _RY in the first power supply terminal ground fault distance relay apparatus 10 ₁ Is output from the trip signal generation circuit 20.
Thus, the first breaker 4 _1, the as shown by the solid line, from the time t _1a at time t _1c which has elapsed total time of the relay determination time T _RY and breaker interruption time T _CB FIGS. 4 (a) Completely blocked. As a result, the conventional case shown by the broken line in FIGS. 4 (a) as compared to (see FIG. 10 (a)), the first breaker 4 ₁ a first power supply terminal ground direction relay device 110 ₁ It is possible to shut off earlier by a time (= 850 ms) obtained by subtracting the total time (= 50 ms) of the relay determination time T _RY and the breaker breaking time T _CB from the operation time limit T _DG1 (= 900 ms).

Next, the first power supply terminal ground fault distance relay apparatus 10 ₁ and the first operation of the opposite end ground fault distance relay apparatus 30 ₁ in the case of ground fault in the power supply end near the own line 1L is generated, This will be described with reference to FIG.

When a ground fault occurs at time t ₀ in the vicinity of the power supply terminal of the own line 1L, the first power supply terminal in which the directions of the _{first to third} line currents I _{1 to} I ₃ are the same as the operation direction (internal direction). The ground fault distance relay device 10 ₁ , the second power source ground fault distance relay device 10 _2, and the first opposite end ground fault distance relay device 30 ₁ operate.

The operating range determination circuit 21 of the trip signal generation circuit 20 (see FIG. 2) included in the first power supply ground fault distance relay device 10 ₁ divides the bus voltage Va by the first line current I ₁ to obtain the first. After calculating the impedance Z ₁ (Z ₁ = Va / I ₁ ), the operation range of the first power source ground fault distance relay device 10 ₁ is one-stage operation based on the calculated first impedance Z _1. It is determined that it is in the area A1, and the first and second determination result output signals VD ₁ and VD ₂ of high level are output.
As a result, the output signal of the _first AND circuit 24 ₁ 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 _second AND circuit 24 ₂ changes from the low level. Become high level. As a result, the output signal of the OR circuit 28 is changed from the low level to the high level, the first trip signal S ₁ is output from the trip signal generating circuit 20 to the first breaker 4 _1.
As shown in FIG. 5A, the first trip signal S ₁ is a time when the relay determination time T _RY in the first power source ground fault distance relay device 10 ₁ has elapsed since the accident occurrence time t ₀ . The trip signal generator 20 outputs the signal at t ₁ .
Accordingly, the first breaker 4 _1, as shown by the solid line in FIG. 5 (a), the time elapsed from the accident occurrence time t ₀ by the total time of the relay determination time T _RY and breaker interruption time T _CB t Completely shut off to _1a . As a result, the conventional case shown by a broken line in FIGS. 5 (a) as compared to (see FIG. 10 (a)), the first breaker 4 ₁ a first power supply terminal ground direction relay device 110 ₁ It can be shut off quickly by the operation time limit T _DG1 (= 900 ms).

In the first opposed end ground fault distance relay apparatus 30 _1, operations area determination circuit 41 of the trip signal generating circuit 40 (see FIG. 3), by dividing the opposite ends bus voltage Vb in the third line current I ₃ a 3 impedance Z ₃ (Z ₃ = Vb / I ₃ ), and based on the calculated third impedance Z ₃ , “the operation range of the first opposing ground fault distance relay device 30 ₁ is two stages. it is determined that the operation zone A2 ", and outputs a second determination result of the high level output signal VD _2. As a result, when the FD relay output signal S _FD ′ is at the high level, the output signal of the _third AND circuit 443 changes from the low level to the high level, but the output signal of the _third AND circuit 443 is delayed. Since the circuit 45 delays the second time-coordinated time GT2 ₃ , the output signal of the delay circuit 45 remains at the low level at time t _1a .
Further, since both line impedances (that is, both line impedances Z _b ) viewed from the opposite end of the own line 1L after the occurrence of the ground fault are equal to or less than the second threshold Th _2b , the output signals of both line Z comparison circuits 43 Although the low level changes to the high level, the impedance (that is, the third impedance Z ₃ ) viewed from the opposite end of the own line 1L after the occurrence of the ground fault is larger than the first threshold Th _1b , so the own line Z comparison circuit The output signal 42 remains at a low level. As a result, the first AND circuit 44 and _second output signal is to become remains low, the third trip signal S ₃ of the output from the trip signal generating circuit 40 remains low.

When the first circuit breaker 4 ₁ is completely cut off at time t _1a , the fault current flows only from the opposite end of the own line 1L toward the fault point (that is, the third line current I ₃ becomes large). Therefore, since the impedance (that is, the third impedance Z ₃ ) from the opposite end of the own line 1L becomes equal to or less than the first threshold Th _1a , the output signal of the own line Z comparison circuit 42 changes from the low level to the high level. The output signal of the _fourth AND circuit 444 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 _fifth AND circuit 445 changes from the low level to the high level. Become a level. As a result, since the output signal of the OR circuit 48 changes from the low level to the high level, the third trip signal S ₃ is output from the trip signal generation circuit 40 to the third circuit breaker 4 ₃ .
The third trip signal S ₃ of, as shown in FIG. 5 (b), the time t _1b from the time t _1a has elapsed the relay determination time T _RY in the first opposing end ground fault distance relay apparatus 30 ₁ Is output from the trip signal generation circuit 40.
As a result, as indicated by the solid line in FIG. 5B, the third circuit breaker 4 ₃ has elapsed for the total time (= 50 ms) of the relay determination time T _RY and the circuit breaker breaking time T _CB from time t _1a . It is completely cut off at time t _1c . As a result, the conventional case shown by a broken line in FIG. 5 (b) in comparison with (FIG. 10 (b) refer), the third circuit breakers 4 ₃ a first power supply terminal ground direction relay device 110 ₁ of It is possible to shut off earlier by the time obtained by subtracting the relay determination time T _RY from the total time of the operation time limit T _DG1 (= 900 ms) and the second time cooperation time T 2 ₃ of the first opposing ground fault direction relay device 120 ₁ . it can.

The first opposing end ground fault distance relay apparatus 30 _1, instead of the trip signal generating circuit 40 shown in FIG. 3, may include a trip signal generating circuit 40a shown in FIG.
As shown in FIG. 6, the trip signal generation circuit 40 a has an inverter circuit 51 that inverts the polarity of the output signal of its own line Z comparison circuit 42 instead of the both line Z comparison circuit 43, and the output signal of the inverter circuit 51. aND circuit which takes the logical product of the OVG output signal S _OVG inputted from the earth fault over-voltage relay apparatus installed at opposite ends bus (second ground fault over-voltage relay device reference 5 ₂ shown in FIG. 7) 52, and an extending circuit 53 that extends the time axis of the output signal of the AND circuit 52 and extends the time DL, and is different from the trip signal generating circuit 40 shown in FIG.

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

When a ground fault occurs in the vicinity of the power supply end 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 tripped from the ground fault overvoltage relay device. It is input to the generation 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 the ground fault occurs, the own line Z comparison circuit 42 The output signal remains low. The output signal of the own line Z comparison circuit 42 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 breaker 4 ₁ is completely blocked by the first power supply terminal ground fault distance relay apparatus 10 ₁ as described above, impedance viewed from the opposite end of its own line 1L (i.e., the 3 impedance Z ₃ ) is equal to or lower than the first threshold Th _1b , the output signal of the own-line Z comparison circuit 42 changes from low level to high level. As a result, the fourth AND circuit 44 ₄ for the high level of the output signal of the high level of the output signal and the spreading circuit 53 of its own line Z comparator circuit 42 is input, a fourth AND circuit the output signal of 44 ₄ from the low 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 _fifth AND circuit 445 changes from the low level to the high level. Become a level. As a result, since the output signal of the OR circuit 48 changes from the low level to the high level, the third trip signal S ₃ is output from the trip signal generation circuit 40 to the third circuit breaker 4 ₃ .

Therefore, even by using a trip signal generating circuit 40a, a third breaker 4 ₃ a first power supply terminal ground direction relay device 110 _first operating time period T _DG1 (= 900ms) and the first opposing end ground The direction relay device 120 ₁ can be shut off earlier by a time obtained by subtracting the relay determination time _TRY from the total time of the second time cooperation time T2 ₃ (see FIG. 5B).

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.

  As described above, the trip signal generation circuit 20, 40, 40a instantaneously generates a trip signal when it detects that the opposite circuit breaker is cut off due to a change in its own line impedance and / or both line impedances. Unlike the protective relay device described in Patent Document 1, it is not necessary to transfer a transfer signal indicating that “the breaker at the opposite end has been cut off”.

Moreover, although the 1st and 2nd power supply ground fault distance relay apparatuses 10 ₁ and 10 ₂ are individually configured, they may be configured integrally. The same applies to the first and second opposing ground fault distance relay devices 30 ₁ and 30 ₂ .

Is a diagram for explaining the power supply terminal ground fault distance relay apparatus 10 ₁ first a distance relay apparatus according to an embodiment of the present invention. First power supply terminal ground fault distance relay apparatus 10 ₁ shown in FIG. 1 is a block diagram showing the configuration of a trip signal generation circuit 20 that comprises. The first opposing end ground fault distance relay apparatus 30 ₁ is a block diagram showing the configuration of a trip signal generation circuit 40 comprising shown in FIG. Operation of the first power supply ground fault direction relay device 10 ₁ and the first counter ground fault direction relay device 30 ₁ when a ground fault occurs near the opposite end of the own line 1L shown in FIG. It is a figure for demonstrating. Operation of the first power supply ground fault direction relay device 10 ₁ and the first opposing ground fault direction relay device 30 ₁ when a ground fault occurs near the power source end of the own line 1L shown in FIG. It is a figure for demonstrating. The first opposing end ground fault distance relay apparatus 30 ₁ is a block diagram showing a configuration of another trip signal generating circuit 40a comprising shown in FIG. It is a figure for demonstrating operation | movement of the ground fault direction relay apparatus used for the ground fault protection in an electric power grid | system. First power supply terminal ground 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 ground fault direction relay device 120 ₁ shown in FIG. 7 is a block diagram showing the configuration of a trip signal generation circuit 140 comprising. Operation of _first power supply ground fault direction relay device 110 ₁ and first counter ground fault direction relay device 120 ₁ when a ground fault occurs on the opposite end side of own line 1L shown in FIG. It is a figure for demonstrating. Operation of the first power supply ground fault direction relay device 110 ₁ and the first opposing ground fault direction relay device 120 ₁ when a ground fault occurs on the power source end side of the own line 1L shown in FIG. It is a figure for demonstrating.

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 4 _first to _fourth circuit breakers 5 ₁ , 5 ₂ first and Second ground fault overvoltage relay devices 10 ₁ , 10 ₂ First and second power supply ground fault distance relay devices 20, 40, 40a, 130, 140 Trip signal generating circuits 21, 41 Operating range determination circuit 22, 42 Self-Line Z Comparison Circuits 23 and 43 Both-Line Z Comparison Circuits 24 _{1 to} 24 ₆ First to Sixth AND Circuits 25 and 45 Delay Circuits 26 and 51 Inverter Circuits 27 and 53 Extending Circuits 28 and 48 Circuits 30 ₁ , 30 ₂ First and second opposing ground fault distance relay devices 44 ₁ -445 ₅ First to fifth AND circuits 52 AND circuits 102 ₁ , 102 ₂ First and second connections terrain instrument transformer 103 ₁ to 103 ₄ of the first to fourth ZCT 110 _1, 110 ₂ first Preliminary second power supply terminal ground direction relay device 120 _1, 120 ₂ first and second opposite ends ground direction relay device 131 and 141 relay determining circuit 132 ₁ to 132 _3, 142 _{1 to 142 3} first Thru | or 3rd delay circuit 133,143 AND circuit 134,144 OR circuit 1L own line 2L other line A1, A2 1 step | paragraph and 2 step | paragraph operation area Va bus voltage Vb opposite end bus voltage V _0a power supply end zero phase voltage V _0b opposite end zero-sequence voltage I ₀₁ ~I ₀₄ first to fourth zero-phase current I ₁ ~I ₄ first to fourth line current Z ₁ to Z ₄ first and fourth impedance Z _a, Z _b Both line impedances Z _{1max to} Z _4max first to fourth maximum impedances Th _1a , Th _2a , Th _1b , Th _2b first and second threshold values DL extension times VD ₁ , VD ₂ first and second Judgment result output signal S _FD , S _FD 'FD relay output signal S ₁ To S ₄ first through fourth trip signal S _C1 to S _C4 first to fourth contact signal S _OVG OVG output signal S _OVG1, S _OVG2 first and second OVG output signal t ₀ ~t _8, t _1a ~t _1c time T _RY relay judgment time T _CB breaker interruption time T _DG1 through T _DG4 operation timed _{GT1 1 ~GT1 4, GT2 1 ~GT2} 4 first and second timed coordination time T1 ₁ ~T1 _4, T2 _{1 to} T2 ₄ , T3 _{1 to} T3 ₄ First to third timed coordination times

Claims (11)

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 A ground fault distance relay device (10 ₁ ),
When the occurrence of a ground fault in the own line is detected, a trip signal generating circuit (S ₁ ) for generating a trip signal (S ₁ ) for breaking the own line breaker (4 ₁ ) provided on the power source end side of the own line ( 20),
When the trip signal generating circuit detects that the opposite end circuit breaker (4 ₃ ) installed on the opposite end side of the own line is cut off based on the change of the own line impedance and the both line impedances, the trip signal Is provided with a trip signal generating means for instantaneously generating
A ground fault distance relay device. The trip signal generating means is
When the own line impedance (Z ₁ ) calculated by dividing the bus voltage (V a) by the own line current (I ₁ ) flowing through the power source end side of the own line is equal to or lower than the first threshold (Th _1a ), an output signal is output. A self-line impedance comparison circuit (22) for outputting;
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 (23) that outputs an output signal when
An inverter circuit (26) for inverting the polarity of the output signal of the own line impedance comparison circuit;
A first logical product circuit (24 ₄ ) that takes the logical product of the output signal of the two-line impedance comparison circuit and the output signal of the inverter circuit;
An extension circuit (27) for extending the time axis of the output signal of the first AND circuit by an extension time (DL);
A second logical product circuit (24 ₅ ) that takes the logical product of the output signal of the own line impedance comparison circuit and the output signal of the extension circuit;
The ground fault distance relay device according to claim 1, comprising: The extension time is longer than a total time of a relay determination time (T _RY ) of the ground fault distance relay device and a circuit breaker cutoff time (T _CB ) of the own circuit breaker. Item 3. A ground fault distance relay device according to item 2. On the condition that the trip line generating means is not interrupted by the adjacent line breaker (4 ₂ ) installed on the power supply end side of the other line, the trip signal generating means The ground fault distance relay device according to any one of claims 1 to 3, wherein the trip signal is generated instantaneously when it is detected that the end circuit breaker is interrupted. The other ground fault distance relay device (10 ₂ ) installed on the power supply end side of the other line has the same configuration as the ground fault distance relay device and is integrally formed. The ground fault distance relay device according to any one of claims 1 to 4. 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. A ground fault distance relay device (30 ₁ ),
When the occurrence of a ground fault in the own line is detected, a trip signal generating circuit (S ₃ ) 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 ( 40; 40a),
When the trip signal generation circuit detects that the power supply circuit breaker (4 ₁ ) installed on the power supply terminal side of the own line is cut off based on the change of the own line impedance, the trip signal is instantly generated. A trip signal generating means for
A ground fault distance relay device. The trip signal generating means is
Output when the own line impedance (Z ₃ ) calculated by dividing the opposite end bus voltage (Vb) by the own line current (I ₃ ) flowing through the opposite end of the own line is equal to or lower than the first threshold (Th _1b ). A self-line impedance comparison circuit (42) for outputting a signal;
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 (43) that outputs an output signal,
A logical product circuit (44 ₄ ) for taking a logical product of the output signal of the own line impedance comparison circuit and the output signal of the both line impedance comparison circuits;
The ground fault distance relay device according to claim 6, comprising: The trip signal generating means is
Output when the own line impedance (Z ₃ ) calculated by dividing the opposite end bus voltage (Vb) by the own line current (I ₃ ) flowing through the opposite end of the own line is equal to or lower than the first threshold (Th _1b ). A self-line impedance comparison circuit (42) for outputting a signal;
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 logical product circuit (44 ₄ ) that takes a logical product of the output signal of the own line impedance comparison circuit and the output signal of the extension circuit;
The ground fault distance relay device according to claim 6, comprising: The extension time is longer than a total time of a relay determination time (T _RY ) of the ground fault distance relay device and a circuit breaker cutoff time (T _CB ) of the own circuit breaker. Item 9. The ground fault distance relay device according to Item 8. On the condition that the trip line generating means is not interrupted by the adjacent line breaker (4 ₄ ) installed on the opposite end side of the other line, the power supply end breaker The ground fault distance relay device according to any one of claims 6 to 9, wherein the trip signal is generated instantaneously when it is detected that the circuit is interrupted. The other ground fault distance relay device (30 ₂ ) installed on the opposite end side of the other line has the same configuration as the ground fault distance relay device and is integrally formed. The ground fault distance relay device according to any one of claims 6 to 10.