JPH0789698B2 - Reclosing method - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to an improvement in a reclosing method for confirming interconnection of a system based on information on a breaker, a disconnector and a disconnector in transmission line protection.

[Technical background of the invention and its problems]

When a fault occurs in a power transmission line, the power transmission line is disconnected from the system and the fault is removed.However, most of the faults in the transmission line are discontinuous. The automatic reclosing method, in which a power transmission line is inserted into the system again and power transmission is restarted after the disappearance time is an effective means for improving the transient stability of the system. As is well known, the reclosing of the system requires that the power supplies at both ends of the transmission line that has been accidentally or disconnected have been operating synchronously. The presence or absence of synchronous operation of the system depends on whether parallel reclosing is required at high speed or parallel 2
When multi-phase reclosing is performed on a circuit transmission line, etc., it is determined by checking the interconnection.

As a method for confirming the interconnection, a method using a tidal current detection relay and a method based on information on a broken wire or a broken wire have been conventionally practiced. The former method installs a power flow detection relay on each phase of its own line and adjacent line, and determines the presence or absence of interconnection based on the presence or absence of tidal current, which has the advantage of being able to perform interconnection confirmation using only the relay at its own end. However, the power flow detection relay must have a high settling value to some extent in order to avoid malfunction due to the charging current of the line. Therefore, if the power flow is less than the set value, there is a risk that it may be erroneously determined that there is no interconnection, and reliable interconnection confirmation cannot be expected. On the other hand, the latter method is a method of detecting the open / closed state of the breaker or the breaker under the pallet condition, and determining that there is interconnection between the self-end and the other end of the protection section by closing the breaker or the breaker. Since it is necessary to transmit the terminal mark and disconnection information, the number of transmitted / received signals increases, but if the transmission means can be easily used, interconnection confirmation can be performed regardless of the presence or absence of tidal current.

Taking the parallel two-line power transmission line of FIG. 1 as an example, a conventional grid connection confirmation method based on the disconnection information and disconnection information in the case where the polyphase reclosing method is applied will be described.

Electric power stations A, B, C are parallel 2-line phase electric wires 1-1 and 1 respectively.
-2 and are connected to each other to form a three-terminal system. The breakers 2a ₁ , 2b ₁ , 2c ₁ and 2a ₂ , 2b ₂ , 2c ₂ are installed at the connection between each electric station and the parallel two-line power transmission station. now,
An internal fault has occurred in the system or the disconnector 2a ₁ , 2b ₁ , 2c ₁ and 2
a _2, 2b _2, when 2c to related accident phase of ₂ or disconnection device is to have been tripped, this case, interconnection between the electrical plant transmission lines 1-
It is maintained by the sound phases 1 and 1-2, but if the number of sound phases satisfies the interconnection condition, reclosing is performed. Normally, the interconnection condition is determined to be established when the two phases are totaled and the sound phase remains with two phases remaining or three phases remaining.

By the way, in general, an electric power plant may be disconnected from the system and put to rest due to operational operations.Because the shut-down operation is performed by opening or disconnecting the switch or opening it, It is not possible to specify whether or not the end is the rest end only by the closed information. Therefore, when the electric station is idle, the grid connection check circuit disables the grid connection between each terminal and the break terminal and the grid break information regardless of the break information sent from the break edge. Need to control.

2 and 3 are logic circuits showing a conventional interconnection confirmation method in a polyphase reclosing circuit. FIG. 2 shows a system for confirming the interconnection between the A end and the B end on Line 1-1 of the electric station A in FIG. 1 for the sake of simplicity. Line 1 R-phase interconnection signal 3R ₁ is the R of line ₁ of electrical stations A and B and disconnector 2a ₁ , 2b ₁ .
When the phase is closed, it is determined that there is R-phase interconnection and it becomes "1".
Line 2 R-phase interconnection signal 3R ₂ is the 2nd line of electrical substation A, B and breaker 2a
_{When the 2} and 2b ₂ R-phases are closed, it is determined that there is an R-phase interconnection, and it becomes "1".

Similarly, the presence or absence of S-phase and T-phase interconnection is determined. Note that 3S ₁ and 3T ₁ indicate interconnection signals of Line 1 S-phase and T-phase, respectively, and 3S ₂ and 3T ₂ indicate interconnection signals of Line 2 S-phase and T-phase, respectively. The interconnection signal of each phase is introduced into each of the OR circuits 4R, 4S, 4T and the OR condition of Lines 1 and 2 is taken for each phase. Next, the interconnection condition determination circuit 5 determines whether or not the multiphase reclosed interconnection condition between the electric stations A and B is satisfied, and the interconnection condition determination output 6 is output to the AND circuit 7. Introduce. One input 8 of the AND circuit 7 is a B-line No. 1 quiescent signal, which will be described later. Therefore, the output of the not circuit 9 is "1", and the output 10 of the AND circuit 7 is the interconnection condition determination output 6 as it is. On the other hand, when the No. 1 line of the electric station B is inactive, the No. 1 circuit No. 1 stop signal 8 becomes “1”, and the AND circuit 7 is locked, so that the A, B interconnection signal 1
Since 0 is controlled to “0”, it is determined that there is no Line 1 interconnection between electric stations A and B. By the way, the pause signal 8 at the B-end 1 line is the pallet condition 1 for each phase of the B-end 1 line and the breaker 2b ₁ in the pause end detection circuit installed at the B end shown in FIG.
AND circuit that 1R, 11S and 11T are all "open"
When it is detected by 12 or when the disconnecting switch condition 13 is "open", the OR circuit 14 judges that the B terminal Line 1 is inactive and "1"
become.

The above interconnection confirmation method is based on Line 1 A of electric station A in Fig. 1.
The explanation was made between the end and the B end, but between the A end and the C end of Line 1 of the electric station A, the A end and the B end of Line 2 and A.
Connection confirmation is also performed between the end and the C end in the same manner.

Now, in parallel 2-circuit transmission line of FIG. 1, when the B-end No.1 rest 15b ₁ a and C-terminal No.1 rest 15c _1, i.e. the internal fault f ₁ in line 1 when the system conditions Figure 4 illustrates Suppose that it has occurred. Note that in FIG. 4, the same parts as those in FIG.

Line 1 1-1 of electric power station A is for breaking faults, and is broken 2a
Fault phase ₁ is tripped. When performing polyphase reclosing,
As the reclosing condition, either the condition of remaining two phases or the condition of remaining three phases in the total of two transmission lines is selected, and the interconnection condition is confirmed. In the case shown in FIG. 4, in the case shown in FIG. -In the interconnection confirmation circuit between B, Line 2 interconnection signal 3R ₂ ,
Since 3S ₂ and 3T ₂ have “1” with interconnection, the condition is satisfied and the judgment output 6 is “1” regardless of whether the interconnection condition is 2 phase remaining or 3 phase remaining. become. Also, the interconnection between A and C is established in the same manner as above. However, since the B-end 1 line 15b ₁ and the C-end 1 line 15c ₁ are paused, the pause-end detection circuit in FIG. 3 detects the pause, and the B-end 1 line pause signal 8 becomes "1". The stop signal for Terminal 1 also becomes "1".
Therefore, although the interconnection condition is satisfied in the A-end interconnection confirmation circuit, the interconnection determination output 6 is locked by the AND circuit 7 by the pause signal of the B-end Line 1 so that there is no A-B interconnection. Since it is controlled to the same way, and similarly between A and C is also controlled without interconnection, the A-route No. 1 line cannot be closed again.

Next, in the parallel two-line power transmission line of FIG. 1, when the B terminal No. 1 line stop 15b ₁ and the C terminal No. 2 line stop 15c ₂ are the 5th line,
Under the system conditions shown in the figure, it is assumed that internal fault f ₂ occurs on Line 1. Line ₁ breakers 2a ₁ and 2c at electric station A and electric station C
_{In case of 1 the} fault phase is tripped for fault elimination. At this time the second
In the diagram, the A-B line A-B interconnection confirmation circuit at the A end of the figure maintains the 3-phase interconnection by Line 2, so the interconnection judgment output 6 is "1".
It becomes a is controlled in the communication system without inter A-B by B end No.1 rest 15b _1. On the other hand, in the A-C interconnection confirmation circuit, Line 1 has an accident cutoff, and Line 2 has a C-terminal pause and there is no interconnection. At times, the condition of interconnection between A and C is satisfied only by the condition of Line 1, but there is no interconnection between A and C when there is a failure of two or more phases. Also, when 3 phase remaining is selected as the interconnection condition,
In all failures, there is no A-C interconnection and reclosing cannot be performed.

As explained above, in the cases of FIG. 4 and FIG.
Despite the fact that the interconnection between the electric stations A and B is established by Line 2, even under the condition that the interconnection condition is forcibly controlled to be unsatisfied by the pause signal from the pause end and reclosing is possible, The reclosing will be blocked. Then, once the line is disconnected from the system, the recovery operation is not easy and requires a considerable recovery time. Therefore, it is important to reclose the line if possible. In the system condition of FIG. 4, even if the B end and C end of Line 1 are both inactive and cannot be reclosed, no supply failure will occur, but the transmission line is always charged and the B end or C end is charged. It is very advantageous from the operational point of view that the system can be connected to the system only by closing the end and disconnecting it.

[Object of the Invention]

The present invention eliminates the drawbacks of the above-mentioned conventional grid connection confirmation by disconnection information and disconnection information, and its purpose is to reclose the grid so that the grid connection can be surely confirmed even in a system with a rest end. To provide the scheme.

[Outline of Invention]

In order to achieve the above-mentioned object, the reclosing circuit of the present invention is such that, for each phase, the other end of the own line is not idle, and the own circuit breaker and disconnector and the other end circuit breaker and disconnector are When all are “closed”, the first means for judging the relevant phase as sound, the second means for judging the sound phase of the other line for each phase as judged in the same manner, the judgment output of the own line and the above It comprises a third means for obtaining a logical sum of the determination outputs of the other lines for each phase having the same name, and a fourth means for determining the presence or absence of interconnection of the system by the number of outputs of the logical addition.

Example of Invention

 An embodiment of the present invention will be described with reference to the drawings.

In order to simplify the explanation, FIG. 7 shows an electric station A-B in line 1 of the electric station A in the three-terminal system shown in FIG.
It is a logic circuit when the interconnection confirmation method according to the present invention is applied between them, and the same parts as those of the logic circuit of FIG. Since the interconnection confirmation method between other electric stations can be configured in the same way as the interconnection confirmation method between the electric stations A and B on the No. 1 line of the electricity station A, the description thereof will be omitted. Line 1 R-phase connection signal 3R ₁ is connected to electrical stations A and B on Line 1 and disconnector 2a ₁ ,
When the R phase of 2b ₁ is closed, it is determined that there is an R phase connection and "1"
become. When the AND condition is satisfied that the R-phase interconnection signal 3R ₂₂ of Line 2 is at Line 2 of the electrical stations A and B, the R-phase of the breakers 2a ₁ and 2b ₂ is closed, and that the B-end Line 2 is not at rest. Line 2 is judged to have R-phase interconnection and becomes "1". Similarly, the presence / absence of S-phase and T-phase interconnection is determined based on the S-phase interconnection signals 3S ₁ and 3S ₂₂ and the T-phase interconnection signals 3T ₁ and 3T ₂₂ . Note that 3S ₁ and 3T ₁
Line 1 S-phase and T-phase interconnection signals, 3S ₂₂ and 3T, respectively
_Reference numerals ₂₂ respectively indicate S-phase and T-phase interconnection signals of Line 2. 1
Signals 3R ₁ , 3S ₁ , 3T ₁ for each phase of the line are AND circuits 17R, 17S, 1
After being introduced into 7T, and the AND condition with the signal obtained by inverting the terminal B line 1 pause signal 8 by the not circuit 9,
The AND condition output 3R ₁₁ , 3S ₁₁ , 3T ₁₁ is OR circuit 4R, 4S, 4T
Will be introduced to. Also, the AND condition outputs 3R ₁₁ , 3S ₁₁ , and 3T ₁₁ are passed to Line 2 as each phase interconnection signal of Line 1.

On the other hand, AND condition output 3R _11, 3S _11, 3T ₁₁ phase interconnection signal line 2 was configured in the same manner as 3R _22, 3S _22, 3T ₂₂ is directly OR circuit 4
Introduced to R, 4S, 4T, AND condition output of Route 1 interconnection signals 3R ₁ , 3S ₁ , 3T ₁ and inversion signal of pause signal 8 3R ₁₁ , 3S ₁₁ , 3T ₁₁ and OR condition for each phase After that, the interconnection condition determination circuit 5 determines whether or not the interconnection condition between the electric stations A and B is satisfied, and outputs the result as an A-B interconnection signal 10. Is.

Next, the operation of the reclosing method according to the present invention will be described.

In the terminal system shown in FIG. 4, if an internal fault f ₁ occurs while Line 1 of the electric power stations B and C is at rest, A-B of the electric power station A
For inter-connection confirmation, each phase interconnection signal 3R ₁ , 3S ₁ , 3T ₁ of line ₁ is locked by the B line 1 line pause signal 8, but each phase interconnection signal 3R ₂₂ , 3S ₂₂ , 3T of line 2 is locked. _{Since 22} has three-phase interconnection and the interconnection condition is satisfied, the A-B interconnection signal 10 becomes "1" and A
The end is interconnected and reclosing is performed. Similarly, for the A-C interconnection, reclosing is performed at the A end.

In addition, in the three-terminal system shown in FIG.
Internal failure of Line 1 and Line 2 of Electric Power Station C during suspension of operation
When f ₂ occurs, the confirmation of the interconnection between A and B at the electric station A is made because the interconnection condition for the three-phase interconnection is established by each phase interconnection signal 3R ₂₂ , 3S ₂₂ , 3T _{22 on} Line 2 The reclosing of is performed. As for the confirmation of the interconnection between A and C, since the interconnection signal of each phase of Line 2 is not interconnected for all three phases due to the suspension of Line 2 at the C end, only the healthy phase of Line 1 is interconnected. Therefore, the interconnection condition is 2
In the case of remaining phases, it is determined that there is no A-C interconnection when there are two or more phases of failures and in the case of all three phases that there are remaining failures, it is possible to select an appropriate reclosing condition.

Further, in the three-terminal system shown in FIG. 6, that is, as in the three-terminal system of FIG. 5, an internal failure f ₃ occurred in Line 2 while Line 1 of Electric Power Station B and Line 2 of Electric Power Station C were at rest. In this case, line 1 will be suspended between A and B and there will be no interconnection due to a line 2 accident. On the other hand, in the confirmation of the interconnection between A and C, since the interconnection signal of each phase of Line 2 is not interconnected for all three phases due to the suspension of Line 2 at the C end, only the healthy phase of Line 1 is interconnected. Therefore, as in the case of FIG. 5, when the interconnection condition is two-phase remaining, there is a failure of two or more phases, and when there are three-phase remaining, there is no A-C interconnection at all failures. Therefore, it becomes possible to select an appropriate reclosing condition.

〔The invention's effect〕

As described above, according to the present invention, in the interconnection confirmation by the circuit breaker information in the reclosing circuit, if there is a pause terminal, only the line having the pause terminal can confirm the interconnection by the breaker information with the pause terminal. Since it was disabled and the interconnection was confirmed with the remaining lines and terminals, proper interconnection confirmation was performed and reclosing was performed as much as possible to enable quick accident recovery in the event of a system failure. A reclosing method can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a three-terminal system diagram of a parallel two-line power transmission line, and FIG. 2 is a circuit diagram of a conventional interconnection confirmation system based on information on a breaker or a breaker.
FIG. 3 is a circuit diagram for detecting an idle end, FIGS. 4 to 6 are three-terminal system diagrams each having a different internal fault and an idle end, and FIG. 7 is a circuit diagram showing an embodiment of the present invention. . 1-1, 1-2 ... Transmission line, 2a ₁ , 2a ₂ , 2b ₁ , ₂ , b ₂ , 2c ₁ , 2c ₂ ... Shiya breaker, 3R ₁ , 3R ₂ , 3S ₁ , 3S ₂ , 3T ₁ , 3T ₂ ...... Each phase interconnection signal, 3R ₁₁ , 3, R ₂₂ , 3S ₁₁ , 3S ₂₂ ,, 3T ₁₁ , 3T ₂₂ ...... Each phase interconnection signal, 4R, 4S, 4T, 14 ...... OR circuit, 7,12, 17R, 17S, 17T …… AND circuit, 5 …… interconnection condition judgment circuit, 6 …… interconnection condition judgment output, 8 …… pause signal, 9 …… not circuit, 10 …… interconnection signal output, 15b ₁ , 15c ₁ , 15c ₂ ...... rest edge, f ₁ , f ₂ , f ₃ ...... Internal failure.

Claims (1)

[Claims] Claim: What is claimed is: 1. In a reclosing method, which determines the presence or absence of grid interconnection based on the number of healthy phases of the transmission line after fault elimination in a two-line transmission line and sets the condition as a reclosing condition. If the other end is not at rest and all the circuit breakers and disconnectors at the own end of the relevant phase of the relevant phase and the other end circuit breakers and disconnectors of the relevant phase are "closed", the relevant phase is regarded as a sound phase. The first means for judging, the second means for judging the sound phase of the other line for each phase by the same means as the first means for each phase of the other line, and the other means of the second means. Using the judgment output of the sound phase of the line and the judgment output of the own line of the first means,
A reclosing circuit comprising: third means for obtaining a logical sum for each phase having the same name; and fourth means for determining the presence or absence of interconnection of the system based on the number of outputs of the logical sum of the third means. method.