JP2014036522A - Protection relay system of parallel double transmission lines - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a protection relay device of parallel double transmission lines capable of precisely determining a system accident using a piece of own information at the protection relay device.SOLUTION: A protection relay system detects an accident occurred on parallel double transmission lines and emits a tripping signal to a breaker. The protection relay system includes: an overcurrent protection relay device that uses a reversed phase second circuit current of the parallel double transmission lines as the polarity quantity; a first protection relay device that gives an operation output by calculating using the reversed phase second circuit current of the parallel double transmission lines as the polarity quantity; and a second protection relay device that gives an operation output by calculating using the reverse-phase current of parallel double transmission lines as the polarity quantity. When both the overcurrent protection relay device and the first protection relay device are activated, or when the overcurrent protection relay device is not activated but the second protection relay device is activated while the parallel double transmission lines are used on the double lines, the tripping signal is given to the breaker.

Description

  The present invention relates to a protective relay system for a parallel two-line power transmission line, and more particularly to a protective relay system for a parallel two-line power transmission line configured by a protective relay device having a reverse phase second circuit current as a polarity.

  2. Description of the Related Art Conventionally, various principles and operation methods have been used as protective relay systems for parallel two-line transmission lines. On the other hand, in recent years, it has been studied to use a protective relay device having a negative phase second circuit current as a polarity amount as a method having little influence such as failure point resistance in a resistance grounding system.

  Patent Document 1 and Patent Document 2 propose a specific circuit configuration of a protective relay device in which the opposite-phase second circuit current has a polarity amount. Among these, Patent Document 1 discloses a specific device that can be put to practical use by using a feather amount when performing a distance measurement calculation by obtaining a reverse phase second circuit current as a polarity amount from a difference current between lines of parallel two-line transmission lines. Proposed configuration. In addition to Patent Document 1, Patent Document 2 also proposes a protective relay device in which the reverse phase second circuit current has a polarity.

JP 2011-45215 A JP 2008-295144 A

  The protective relay device using the reverse-phase second circuit current as a polarity has attracted attention as a new protection method with less influence of the system, but only proposed a specific circuit configuration such as the above-mentioned patent document.

  In order to actually operate as a protective relay system for parallel two-line transmission lines, it is necessary to propose a system configuration that operates correctly in each operation or event of the parallel two-line transmission lines. For example, during normal operation with a two-line power transmission line, when a single-line accident occurs, when a single-line / partner end close accident, etc. can be performed correctly, and when a parallel two-line power transmission line is operated in the same way It is necessary to obtain a protection system configuration that can correctly perform a protection operation even in the event of a one-line failure.

  From the above, in the present invention, the parallel 2 mainly composed of the protective relay device having the polarity of the reverse phase second circuit current that can operate correctly in each operation or event of the parallel two-line transmission line. It aims at providing the protection relay system of a circuit transmission line.

A protective relay system for detecting an accident occurring in a parallel two-line transmission line and giving a tripping signal for a circuit breaker,
An overcurrent protection relay device that uses the opposite-phase second circuit current of the parallel two-line transmission line as a polarity amount, and a first operation that gives an operation output by calculation using the opposite-phase second circuit current of the parallel two-line transmission line as a polarity amount. And a second protective relay device that provides an operation output by a calculation using the reverse phase current of the parallel two-line power transmission line as a polarity amount,
When the parallel two-line transmission line is operated with two lines, when the overcurrent protection relay device and the first protection relay device operate together, or the overcurrent protection relay device does not operate and the second A circuit breaker trip signal is provided when the protective relay device operates.

  According to the protection relay system for a parallel two-line power transmission line of the present invention, it is possible to correctly give a tripping signal for a circuit breaker to an accident case during the operation of one or two lines of a parallel two-line transmission line. This can be constituted by a protective relay device in which the reverse phase second circuit current has a polarity.

The figure which shows the structure of the protection relay apparatus of the parallel 2 line power transmission line which concerns on this invention. The figure which shows the state of the parallel 2 circuit power transmission line in the normal time, and the mode of each part current at this time. The figure which shows the state of the parallel 2 line power transmission line at the time of an accident (at the time of 1 line accident), and the mode of each part current at this time. The figure which shows the state of the parallel 2 line power transmission line at the time of an accident (at the time of 1 line and the other party's near end accident), and the mode of each part current at this time. The figure which arranged the relation between the input and the output of the protective relay device for each assumed event.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a configuration of a protective relay device for parallel two-line power transmission lines according to the present invention. In the present invention, the protection relay device 44GN (for example, the ground fault distance protection relay device) having the polarity of the reverse-phase second circuit current as the main amount is used as the main, and the protection relay device 44G ( For example, a ground protection distance relay device), an overcurrent protection relay device 50I22 having a reverse phase second circuit current as a polarity, and a two-line use condition 100 are combined to provide a final protection relay system output (trip output) To do. AND is a logical product circuit.

  Here, the negative phase second circuit current is obtained by subtracting the negative phase current of the second line from the negative phase current of the first line with respect to the negative phase current of each line obtained from the phase current of each line. It is.

  According to the logic of FIG. 1, the AND circuit AND1 includes an overcurrent protection relay device 50I22 for the negative phase second circuit current and a protective relay device 44GN having the negative phase second circuit current as a polarity amount when two circuits are operated. Act as a trip signal for the circuit breaker.

  In addition, the AND circuit AND2 has a circuit breaker when the overcurrent protection relay device 50I22 for the reverse phase second circuit current does not operate when the two-line operation is performed and the protection relay device 44G having the polarity of the reverse phase current operates. And a trip signal.

  Further, the AND circuit AND2 serves as a trip signal for the circuit breaker when the protective relay device 44G having the polarity of the reverse phase current is operated during the operation of one line.

  The correct operation by the protective relay device and the output logic circuit configuration of FIG. 1 will be described below with reference to FIGS. 2 shows the normal state, FIG. 3 shows the state of the parallel two-line transmission line and the current of each part at the time of the accident (at the time of the one-line accident), FIG. Is shown. FIG. 5 shows the operating state of each part of the circuit of FIG. 1 and the presence or absence of signals in each of these cases.

  2, 3, and 4, G is a rear power source, an electric station where a protective relay device on the side of the rear power source G is installed is a local power station (hereinafter simply referred to as a local terminal), and a parallel two-line power transmission line LA , LB is an electric station connected to the other end (hereinafter simply referred to as the other end), and F is an accident point. The transmission lines LA and LB may be referred to as a first line and a second line.

In these figures, I ₂ is a negative phase current, I _A2 is a negative phase current of the first line LA, I _B2 is a negative phase current of the second line LB, and I _2X is a negative phase second circuit current. Further, it denoted the current of the first line LA _{I A,} the current of the second line LB as _{I B.}

In the normal operation of the parallel two-line transmission line in FIG. 2, the negative phase current I ₂ , the negative phase current I _A2 of the first line LA, the negative phase current I _B2 of the second line LB, and the current I _2X of the negative phase second circuit are , Both are almost zero. Further, the current _{I A} of the first line LA current _{I B} of the second line LB is substantially the same current value.

Therefore overcurrent protective relay device of the negative-phase second circuit current first line LA of the current I _A and the differential current between the current I _B of the second line LB (inverse-phase secondary circuit current I _2X) and polar amount 50I22 Does not operate and its output is “0”.

Further, the protective relay device 44GN having the reverse phase second circuit current I _2X having the polarity amount does not operate and its output is “0”. Ground fault distance relay device 44G for the negative sequence current I ₂ and the polar amount not operate the output is "0".

  Since the two-line use condition circuit 100 outputs “1” in the two-line operation state, the output of the AND circuit AND3 reflects the output of the overcurrent protection relay device 50I22 for the negative-phase second circuit current as it is. Therefore, in the following description of the two-line operation, the description will be made in comparison with the output of the direct overcurrent protection relay device 50I22.

  In this case, the logical product of the circuit breaker trip signal when both the overcurrent protection relay device 50I22 for the reverse phase second circuit current and the protective relay device 44GN having the polarity for the reverse phase second circuit current operate together. The circuit AND1 does not output.

  The AND circuit AND2 which makes the trip signal of the circuit breaker when the overcurrent protection relay device 50I22 for the reverse phase second circuit current does not operate and the ground fault distance relay device 44G operates does not give an output.

  As described above, the circuit shown in FIG. 1 does not give a trip signal at normal time, and correct protection operation can be executed.

In the case of the parallel two-line transmission line accident in FIG. 3 (at the time of one line accident), an accident on the first line LA is assumed. In this case, all of the negative phase current I ₂ , the negative phase current I _A2 of the first line LA, the negative phase current I _B2 of the second line LB, and the negative phase current I _2X of the second circuit are generated. The size is not zero. However, the reverse phase current I _A2 of the first line LA that has caused the one-line _fault is sufficiently larger than the reverse phase current I _B2 of the second line LB that has not caused the fault.

In this case, the current _{I A} of the first line LA first second line LB of the current _{I B} of the magnitude the difference current because it is of a sufficiently large value with respect of _(I A _-I B) (reverse phase The two-circuit current I _2X ) becomes larger than the operation determination value I _S, and the overcurrent protection relay device 50I22 for the negative-phase second circuit current having this as a polarity amount operates, and its output is “1”.

In addition, when the current I _2X of the negative phase second circuit is generated, the protective relay device 44GN is operated by the distance measurement calculation using the current I _2X as a polarity amount, and the output is “1”. The larger than even the operation judging value I _S by the operation of the polarity amount reverse-phase current I _2, which also operates ground fault distance relay device 44G to polar amount the output is "1".

  In this case, since the overcurrent protection relay device 50I22 for the reverse phase second circuit current and the protection relay device 44GN having the polarity for the reverse phase second circuit current are operating together, the AND circuit AND1 operates the circuit breaker. Output a disconnect signal.

  On the other hand, the reverse circuit second circuit current overcurrent protection relay device 50I22 does not operate and the ground fault distance relay device 44G operates, and the AND circuit AND2 side that becomes a tripping circuit breaker signal reverses Since the overcurrent protection relay device 50I22 for the phase second circuit current operates, the output of the AND circuit AND3 becomes “1”, and the trip signal output signal of the circuit breaker is not given.

  In the case of the two-line operation and the one-line fault, as a result, the overcurrent protection relay device 50I22 for the negative phase second circuit current and the protective relay device 44GN having the negative phase second circuit current as a polarity amount are provided. Based on the state in which both are operating, it is determined that there is a parallel two-line power transmission line accident (at the time of one line accident) and the circuit breaker is removed. As a result, a correct protection operation can be performed.

In the case of the parallel two-line transmission line accident in FIG. 4 (at the time of one line and the other end near-end accident), an accident near the other end is assumed. In this case, all of the negative phase current I ₂ , the negative phase current I _A2 of the first line LA, the negative phase current I _B2 of the second line LB, and the negative phase current I _2X of the second circuit are generated. The size is not zero.

However, the distance from the own end to the accident point F on the first line LA where the one line accident occurred and the first line LA where the one line accident occurred from the own end via the second line LB and the other end In this case, the distance to the accident point F is close. In this case, the reverse phase current I _A2 of the first line LA that caused the one line fault is larger than the reverse phase current I _B2 of the second line LB that has not caused the fault, but the current difference is small. Is the feature. Similarly, the current _{I A} of the first line LA, the current difference between the current _{I B} of the second line LB is small.

As a result, approximately equal magnitude of the current _{I A} and the current _{I B} of the second line LB of the first line LA, because the difference current _(I A -I _B) is smaller than the operation judging value _{I S} reversed phase The overcurrent protection relay device 50I22 for the second circuit current does not operate, and its output is “0”.

Further, the protective relay device 44GN having the polarity of the current I _2X of the reverse phase second circuit cannot operate, and its output is “0”.

Note negative sequence current I ₂ is greater than the operation judging value I _S, which ground fault distance relay device 44G to polar amount is operated and its output is "1".

  In this case, the AND circuit AND1 on condition that the overcurrent protection relay device 50I22 for the reverse phase second circuit current and the protection relay device 44GN having the polarity of the reverse phase second circuit current are operating together. Because both do not operate, the trip signal of the circuit breaker is not output.

  On the other hand, on the AND circuit AND2 side where the overcurrent protection relay device 50I22 for the reverse phase second circuit current does not operate and the ground fault distance relay device 44G operates, the circuit breaker trip signal becomes a condition. Is established and a tripping signal output of the circuit breaker can be given.

  In this case, as a result, when the overcurrent protection relay device 50I22 for the reverse phase second circuit current does not operate and the ground fault distance relay device 44G operates, a parallel two-line power transmission line fault (1 line)・ Determine that the other end and the near-end accident) and then trip the circuit breaker. As a result, a correct protection operation can be performed.

  As described above with reference to FIGS. 2, 3, 4, and 5, a correct operation result can be obtained by the logic circuit shown in FIG. 1 in each case of two-line operation. Next, it will be described that this logic circuit can operate correctly even when one line is operated.

  However, in the case of one-line operation, the two-line operation condition circuit 100 gives an output “0”. Therefore, the output of the AND circuit AND3 is “0” regardless of the operation of the overcurrent protection relay device 50I22 for the negative-phase second circuit current. As a result, the logic circuit AND1 does not become “1” during one-line operation. Therefore, only the logic circuit AND2 needs to be determined.

Based on this premise, the normal state at the time of one-line operation of only the first line LA will be described first. At this time, the negative phase current I ₂ and the negative phase current I _A2 of the first line LA are both substantially zero. The reverse-phase current I _B2 of the second line LB which is not operated is zero, does not detect the second circuit currents reverse phase since no form reverse-phase second circuit during one line operation.

  Therefore, in the case of the overcurrent protection relay device 50I22 for the negative phase second circuit current with the polarity of the negative phase second circuit current (difference current), the overcurrent protection relay device 50I22 for the negative phase second circuit current is It does not operate and its output is “0”.

Further, the protective relay device 44GN having the polarity of the negative phase second circuit current having the polarity of the negative phase second circuit current I _2X does not operate and its output is “0”. Ground fault distance relay device 44G for the negative sequence current I ₂ and the polar amount not operate the output is "0".

  In this case, the AND circuit AND1 that outputs the circuit breaker trip signal when the protection relay device 44GN having the polarity of the output of the AND circuit AND3 and the second-phase circuit current of the opposite phase operates together does not output. The output itself of the AND circuit AND3 is “0”.

  On the other hand, there is no output from the AND circuit AND3, and the AND circuit AND2 that makes the trip signal of the circuit breaker when the ground fault distance relay device 44G operates does not give any output. The logic of the AND circuit AND2 is not established due to the malfunction of the ground fault distance relay device 44G. As a result, a correct protection operation can be performed.

Next, an accident state at the time of one line operation of only the first line LA is described. At this time, a negative phase current I ₂ and a negative phase current I _A2 of the first line LA are generated. However, the reverse phase current I _B2 of the second line LB that is not operated is zero.

Therefore overcurrent protective relay device 50I22 reverse phase second circuit current to polarity quantity difference current of currents I _A and the current I _B of the second line LB of the first line LA, the operation detects the difference current The output is “1”.

The protective relay device 44GN having the opposite phase second circuit current I _2X having the polarity amount and the opposite phase second circuit current having the polarity amount is also operated, and its output is “1”. In contrast, the ground fault distance relay device 44G for the negative sequence current I ₂ and the polar amount operates by detecting the negative sequence current of sufficient magnitude, the output "1".

  In this case, the AND circuit AND1 that outputs the circuit breaker trip signal when the protection relay device 44GN having the polarity of the output of the AND circuit AND3 and the second-phase circuit current of the opposite phase operates together does not output.

  The AND circuit AND2, which has no output from the AND circuit AND3 and operates as the circuit breaker trip signal 44G by operating the ground fault distance relay device 44G, satisfies the condition and gives a circuit breaker trip signal. As a result, a correct protection operation can be performed.

  FIG. 5 shows the relationship between the input and output of the protective relay device in the embodiment of FIG. According to FIG. 5, the protective relay device for the parallel two-line power transmission line according to the present invention can correctly provide a tripping signal for a circuit breaker for accident cases during two-line operation and one-line operation. It can be clearly understood that the device does not operate when the one-line operation and the two-line operation are normal.

44GN: Protective relay device 44G having the polarity of the reverse phase second circuit current 44G: Protective relay device 50I22 having the polarity of the negative phase current circuit: Overcurrent protection relay devices AND1, AND2, AND3: AND circuits I _A , I _B : current of the first line LA, current I ₂ , I _A2 , I _{B2 of} the second line LB: negative phase current I _2X : current of the negative phase second circuit

Claims (4)

A protective relay system for detecting an accident occurring in a parallel two-line transmission line and giving a tripping signal for a circuit breaker,
An operation output is given by an overcurrent protection relay device that uses the opposite-phase second circuit current of the parallel two-line transmission line as a polarity amount, and a calculation that uses the opposite-phase second circuit current of the parallel two-line transmission line as a polarity amount. A first protective relay device, and a second protective relay device that provides an operation output by a calculation with a reverse phase current of the parallel two-line power transmission line as a polarity amount,
When the parallel two-line power transmission line is operated with two lines, the overcurrent protection relay device and the first protection relay device operate together, or the overcurrent protection relay device does not operate. A protection relay system for a parallel two-line power transmission line, wherein a tripping signal for the circuit breaker is given when the second protection relay device operates. A protection relay system for a parallel two-line power transmission line according to claim 1,
When the parallel two-line power transmission line is operated with one line, the circuit breaker trip signal is given by the operation of the second protective relay device. Electric system. A protective relay system for detecting an accident occurring in a parallel two-line transmission line and giving a tripping signal for a circuit breaker,
An operation output is given by an overcurrent protection relay device that uses the opposite-phase second circuit current of the parallel two-line transmission line as a polarity amount, and a calculation that uses the opposite-phase second circuit current of the parallel two-line transmission line as a polarity amount. A first protective relay device, and a second protective relay device that provides an operation output by a calculation with a reverse phase current of the parallel two-line power transmission line as a polarity amount,
When the parallel two-line transmission line is operated with two lines, the overcurrent protection relay device and the first protection relay device operate together to detect an accident on one line, and the overcurrent When the protective relay device does not operate and the second protective relay device operates,
When the parallel two-line transmission line is operated with one line, the second protective relay device operates together to detect an accident with one line and give the trip signal for the breaker A protective relay system for parallel two-line transmission lines. A protective relay system for detecting an accident occurring in a parallel two-line transmission line and giving a tripping signal for a circuit breaker,
An operation output is given by an overcurrent protection relay device that uses the opposite-phase second circuit current of the parallel two-line transmission line as a polarity amount, and a calculation that uses the opposite-phase second circuit current of the parallel two-line transmission line as a polarity amount. A first protective relay device, and a second protective relay device that provides an operation output by a calculation using a reverse phase current of the parallel two-line power transmission line as a polarity amount;
A third AND circuit for confirming the condition that the parallel two-line power transmission line is operated by two lines and the operation of the overcurrent protection relay device, the third AND circuit and the first protection relay A first AND circuit for confirming the operation of the electric device, a non-operation of the third AND circuit and a second AND circuit for confirming the operation of the second protective relay device,
A protection relay system for a parallel two-line power transmission line, characterized in that a trip signal for the circuit breaker is provided when either the first logical product circuit or the second logical product circuit is established.

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