JPS5930013B2 - Phase comparison transport protection relay system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a protection system in the event of multiple faults spanning both lines of a phase comparison relay device.

As a protective relay device for an important power transmission line such as the so-called main power transmission line of an electric power system, a high-speed operation, highly reliable carrier protection relay device with excellent protection performance is generally employed.

In particular, ultra-high-voltage and ultra-super-high-voltage power transmission lines are equipped with phase-comparison transport protection relay devices that can apply a multi-phase reclosing method that selectively cuts off only the failed phase and recloses it at high speed.

This phase comparison carrier protection relay device correctly responds to and eliminates accidents between the terminals of the line in which it is installed, and conventional devices were able to respond correctly to various accidents within their protection responsibilities.

However, it was newly discovered that the system was malfunctioning due to an accident on an adjacent line, which was not originally under its protection responsibilities.

To explain this phenomenon, this is a parallel two-circuit power transmission line with a phase comparison transport protection relay device installed at each terminal.
This became a problem when accidents occurred on both lines at the same time.

At this time, the phase comparison relay device operates, and the circuit breaker of only the fault phase is tripped for all four terminals, the fault is removed from the system, and the tripped circuit breaker is turned on again after the reclosing no-voltage period. .

At this time, if Line 1 is in an arcing accident and Line 2 is in a permanent accident, Line 2 will continue to have an accident due to re-closing, so the phase comparison relay will detect this and issue an output again. The circuit breakers at both terminals are then tripped for all three phases, regardless of the fault phase, removing the fault from the system.

However, Line 1 was cut off by the phase comparison relay due to an arcing accident, and the accident disappeared and the circuit was successfully reclosed.
It should be possible to continue stable operation.

However, as will be explained in detail later, conventionally, a continuous trip permission signal (hereinafter referred to as continuous F2 signal) is sent to the other end during the breaker open period, so the phase comparison relay device has not yet recovered when the breaker is reclosed. I haven't.

Then, because the voltage has dropped due to a permanent fault on the adjacent line, the undervoltage relay is also in operation, and the re-closing failure detection condition for line 1 is met, and at the same time as line 1 is reclosed, it is cut off again like line 2. become.

In other words, originally two-line operation becomes one-line operation, but the grid connection between both terminals is maintained and power supply is supposed to continue, but an accident occurs on both lines at the same time, causing a single-line arcing accident. In the case of a permanent fault on one line, as long as the conventional phase comparison transport protection power cutoff device is installed, both lines will be cut off, resulting in an unnecessarily divided system, and the reliability of the system will drop significantly.

The present invention was made in view of these newly discovered problems, and an object of the present invention is to solve the problem by allowing the phase comparison relay to be restored more quickly than the circuit breaker has to be turned on again.

Specifically, continuous F is applied only during the excitation period of the breaker row removal coil.
It is designed to give two signals.

An embodiment of the present invention will be described below.Prior to that, the operating principle of the phase comparison transport protection relay system for each phase will be explained with reference to FIGS. 1 and 2, and the conventional continuous F2 signal control circuit with reference to FIG. I will explain.

FIG. 1 shows a power system in which a phase comparison relay 7 is installed, and the phase comparison relay is installed at an electric station A and an electric station B.

Items common to both electrical stations are designated by the same reference numerals.

Reference numeral 1 indicates a busbar, and reference numeral 2 indicates a generator behind the power station. When a fault occurs on the power transmission line, the fault current is supplied from this generator.

The busbars 1 of electric stations A and H are interconnected by a power transmission line 5 via a circuit breaker 4, respectively.

When an accident occurs on the power transmission line 5, the relay side current 6 proportional to the fault current flowing through the power transmission line 5 is guided by the current transformer 3 installed at both electric stations to the phase comparison relay 7, and the output circuit 11 of 7 The circuit breaker 4 is opened.

The current 6 guided to the phase comparison relay 7 is converted from a sinusoidal alternating current into a rectangular wave by a rectangular wave shaping circuit 8 inside the phase comparison relay.

The relay side currents 6A and 6B detected at both electric stations have the same polarity when a passing current occurs in the event of an external fault as shown in FIG. 2a.

In the phase comparison relay that is treated as the power supply end of electric station A, the rectangular wave made of a positive half wave that exceeds level LH becomes a trip-permissible phase signal (hereinafter referred to as F2 signal), and the other sections are tripped. This becomes a lock phase signal (hereinafter referred to as F, double signal).

In addition, in the phase comparison relay that is treated as a variable power supply terminal at electric station B, the rectangular wave created by the current on the side that includes zero from level LL becomes the F2 signal, contrary to the power supply terminal, and the other sections are F1. It becomes a signal.

The phase signal generated by the rectangular wave shaping circuit 8 is guided to the matching circuit 9 (actually, it passes through a circuit that compensates for the transmission delay time until the phase signal transmitted from the other end reaches the matching circuit 9 at the other end). is omitted here for the sake of brevity), and is simultaneously transmitted to the transmitter 13 of the information transmission device 12, and generally further transmitted to the receiver 14 of the other party's information transmission device 12 via the microwave line 15. Ru.

On the other hand, in the same way, the other end phase signal sent from the transmitter 13 of the other end information transmission device 12 through the microwave line 15 passes through the receiver 14 of the information transmission device 12 at the other end, and then passes through the phase comparison relay 7. It is introduced into another input of the matching circuit 9.

In the matching circuit 9, a No. 1 of the F2 signal at both ends is created, and if this magnitude is measured by the next integrating circuit 10 and is large enough to be judged as an internal accident that should be protected (generally 60 degrees) or more, the output circuit is activated. 11, a command to trip the circuit breaker 4 is issued.

Although only one set of phase comparison relays is shown in FIG. 1, in reality they are installed for each of the A, B, and C phases, and the above-mentioned operation is performed independently for each phase.

Next, referring to FIG. 2, the response of the device shown in FIG. 1 to a system accident will be explained.

Components in FIG. 2 that are the same as those in FIG. 1 are designated by the same reference numerals.

Figure 2a shows the response to an accident outside the protected area, and as shown, the accident point F is outside the electrical station B.

Therefore, the current on the relay side of the transformer 3 is A terminal 6A and B terminal 6B.
Then, both the size and the phase will be the same.

The A terminal current, which is treated as the power supply terminal, is converted into a rectangular wave by the slice level LH in the rectangular wave shaping circuit 8 as shown in 8A, and then F2
The other sections are F1 signals.

The B terminal current, which is treated as a variable power supply terminal, is converted into a rectangular wave by the slice level LL in the rectangular wave shaping circuit 8, and is converted into an F2 signal as shown in B, contrary to the electrical station A, which is treated as a power supply terminal, and an F1 signal in other sections. become.

The matching circuit 9 ANDs the F2 signals of 8A and 8B, but as shown in 9(A, B), the AND output of 9 becomes, and therefore the integrating circuit of 10 and the output circuit of 11 each receive 10( A.

B), 11 As shown in (A, B), there is no signal at all, so if the breaker trip signal comes out, it is not good luck.

It is a well-known fact that the slice level LH at the power source end and the slice level LL at the variable power source end are configured such that LH>LL so that the F2 signals at both ends do not overlap due to an external accident.

Figure 2 shows the case of an internal accident when power is supplied at both ends, and as shown, there is an accident point F on the power transmission line 5 connecting electric station A and electric station B.

Due to an internal accident in the section, the current on the relay side of transformer 3 is almost in opposite phase at terminal A 6A and terminal B 6B, and the current is 8A, contrary to Fig. 2a.
, 8B, a phase signal is generated at each terminal station,
Since F1 signal and F2 signal are generated, matching circuit 9 at both ends
(A, B), a coincidence output as shown appears, and if this is measured (integrated) by the integrating circuit 10, 10 (A, B)
As shown in FIG. 2, the slice level RL of the integrating circuit is reached, and the output circuit 11 (A, B) outputs an output, and this signal opens the circuit breaker and eliminates the accident F.

In Figure 2 C, the accident point is inside the protected area as in Figure 2, but unlike in Figure 2, there is no power source behind electric station B at the variable power source end (there is no generator 2), so B This is the case where no fault current is supplied from the end.

Therefore, 6A and 8A are exactly the same as in figure b.

However, as shown in 6B, the current at the B end is not completely heated, so it is always below the LL level, and as shown in 8B, it is F over the entire section.
2, that is, it becomes a phase signal that allows continuous tripping.

Therefore, the F2 signal of 8A appears as it is in the double-end coincidence circuit 9 (A, B), and 10 (A, B), 1 (A, B)
) clearly gives a breaker trip signal.

In other words, if it is treated as a variable power supply terminal, the breaker can be tripped even if no fault current flows.

Using Figure 3, Figure 4, Figure 6, and Figure 1, in the case of the simultaneous accident on both circuits mentioned earlier, with an arcing accident on Line 1 and a permanent accident on Line 2, the circuit was successfully reclosed and stable operation continued. 1 that should be possible
We will explain in detail the defects that cause the line to be cut off again due to permanent accidents.

Of the components shown in these figures, those that are the same as those in FIG. 1 are denoted by the same reference numerals, and it is clearly stated here that this concept is followed in the drawings that appear below.

First of all, Figure 3a shows the power system in which the phase comparison relay is installed, similar to Figure 1, but unlike Figure 1, electric station A and electric station B are connected to a two-circuit transmission line, that is, one line 5. It is interconnected with -1L through a bisecting line 5-2.

It is assumed that the accident point on Line 1 is FA, and an arc accident has occurred.

Therefore, if the circuit breakers 4 at both ends of 5-1L are opened, the fault FA will disappear, so if the circuit breakers 4 at both ends of 5-1L are turned on again after a no-voltage period, the system should return to its original stable state. be.

It is assumed that the accident point on Line 2 is FP and a permanent accident has occurred.

Therefore, even if the circuit breaker 4 at both ends of 5-2L is opened and then reclosed, the accident continues and the circuit is shut off again, and the circuit breaker 4 at both ends of 5-2L remains open.

Figure 3 shows the concept of a breaker circuit, where 7-a is a normally open contact that closes when the phase comparison relay operates, and 16 is a normally open contact of an undervoltage relay for fault detection, which is used to detect faults in the system. , it operates and closes when undervoltage is detected.

PS is a breaker pallet switch that is linked to the breaker and opens when it opens.

Therefore, if an accident occurs inside the protected area in the system, contact 7
-a and 16 are closed, so a cutoff command is issued from the operation bus P to the cutoff coil TC of the breaker, and the breaker is opened.

When the breaker opens, the pallet switch PS also opens.

In this way, the reason why the cutoff coil TC is excited for a short time is that the current in this circuit causes the contact 7-a to be energized.

This is for the purpose of preventing damage to the 16.

The auxiliary relay 28 and the contact point TC-1 of the extraction coil TC are added according to the present invention, and will be explained later.

FIG. 4 shows a transfer control circuit for sending Fl and F2 signals formed from the currents at each end to the other end.

17 is a contact of a coil that is energized by a pallet switch when the breaker contact is opened, and is closed when the breaker is opened.

18-1 is a contact of a coil (described later) which is energized by the excitation signal of the closing coil for re-closing the breaker, and is opened when the closing coil is excited.

OR represents an OR gate, and PT represents a signal power supply.

In this circuit, when the breaker is closed, the contact 17 is open, and when there is a signal from the rectangular wave shaping circuit 8 of the phase comparison relay 7 to the transmitter 13 of the information transmission device 12, the F2 signal is transmitted to the transmitter. When there is no signal to F13, the F1 signal is sent to the other end.

Then, when a cutoff command is issued and the breaker opens, contact 17
Since the circuit is closed, a signal is continuously supplied to the transmitter 13 from the power supply PT, so a continuous F2 signal is transmitted to the other end, and this continues until the breaker is turned on again.

Here, the reason why the continuous F2 signal is forcibly generated when the circuit breaker is open is explained. One of the reasons is to facilitate the circuit breaker, especially at the end of the variable power supply.

In other words, a) if the breaker at the power end side opens in advance for some reason when an accident occurs, or b) an internal accident occurs when only the breaker at the power end side is opened and the line is being charged from the variable power end side. Considering that, the carrier signal sent by the phase comparison relay at the power supply end is a continuous F1 (trip prevention) signal because the current detected by it is zero due to the opening of the breaker, and the carrier signal sent by the phase comparison relay at the power supply end is a continuous F1 (trip prevention) signal. Regardless of the situation, the breaker array cannot be removed at the variable power source end.

The second reason is that one of the conditions for allowing reclosing is that there is a total of two or more phases of interconnection between two circuits.

” can be given.

This is to confirm that the power supplies at both ends of a two-line power transmission line are synchronized. For example, in the first line, the A and B phases are open due to an accident, and in the second line, the B and C phases are open. Assuming that the phase is open, two phases (A, C) are interconnected between both ends.

On the other hand, if the A phase and B phase of both the first and second lines are open, only the C phase is interconnected.

In the former case, the remaining one phase is also considered to be in a synchronized state, but in the latter case, where only one of the three phases is interconnected, synchronization cannot be guaranteed.

Needless to say, reclosing without confirming synchronization is not allowed, and the easiest and most reliable way to confirm two-phase interconnection at the other terminal at the own terminal is to detect the continuous F2 signal when the breaker is opened. It depends.

In order to determine whether the accident continues after the breaker is turned on again, contact 18-1 is opened at the same time as the closing coil is energized to cancel the continuous F2 signal.

Figure 6 shows the re-closing circuit of the breaker, and Figure 7 shows the signal waveforms at various parts after the occurrence of an accident until the breaker is re-closed (I is on the variable power supply end, ■ is on the power supply end) It shows.

To explain the functions of Fig. 3b1 and Fig. 4 up to accident removal using Fig. 7, the accident occurrence time t.

In the previous state, the response was similar to that at the time of the external accident shown in FIG. 2a, and since the carrier signal 15 sent out by one electric station is the F1 signal, the other is the F2 signal.

Due to the occurrence of an accident, the carrier signals sent from both ends become almost in the same phase, and the F2 signals match.

As a result, before t, both the undervoltage relay 16 and the phase comparison relay 7 are in a non-operating state, and when an internal fault occurs, they are activated to open the circuit breaker 4 at time t1.

However, t is the time when the F2 signal matches the delayed phase signal from the own end and the phase signal from the opposite end, and this state continues for a predetermined period of time and the phase comparison relay 7 enters the operating state.

Set to 1.

The contact 17 in FIG. 4 is closed when the circuit breaker 4 is opened, and thereafter the carrier signal 15 transmitted from its own end becomes a continuous F2 signal as shown by the solid line.

The operation up to this point is exactly the same at the power supply terminal and the variable power supply terminal.

By opening this breaker, the voltage is restored and the undervoltage relay 1
6 is inoperative at either terminal, but when looking at the phase comparison relay T, it is inoperable at the power supply end (at the power phase end, where a continuous F2 signal is obtained from the other end, the current is zero, so the level corresponding to the continuous F1 signal is It's a signal.

), the variable power source terminal operates (a continuous F2 signal is obtained from the other end, and since the current is zero at the own end, the signal is at a level equivalent to the continuous F2 signal).

) continues.

FIG. 7I shows the variable power supply end, and it is the variable power supply end that will malfunction in the event of an accident spanning both lines.

The reclosing circuit of FIG. 6 is at the time t when this accident is detected.

Start operation from 1.

In this FIG. 6, 97 is the trip circuit of the circuit breaker 4 (
This is a contact that closes when a cutoff command is issued from FIG. 3b), thereby exciting the auxiliary relay 34.

34-1 is the contact point of 34.

Reference numeral 26 is a contact that is closed only when re-closing is performed. For example, during single-end line charging operation in which one breaker is opened and the line is charged only from one end, re-closing is not performed, so contact 26 is closed. It remains as it was.

23 is a timer for measuring no-voltage time;
7 and 27-1 are auxiliary relays and their contacts for self-maintaining the operation of the timer 23.

Timer 23 closes contact 2 at time t2 after the no-voltage time has elapsed.
3-1 is closed.

18, 20.21 is the auxiliary relay coil, 20-1.2
0-2 is the normally open contact of the coil 20, 21-1 and 21-2 are the normally open contacts of the coil 21, 22 is the normally closed contact of the auxiliary relay that is energized when the breaker is re-closed, and 23-1 is the normally open contact of the auxiliary relay. The normally open contact 24-1 of the timer 23 that counts the no-voltage time from the fault removal time t1 is the auxiliary relay 24 ( (described later with reference to FIG. 9) normally open contacts, 2
5 is a normally closed contact of an auxiliary relay that is energized in the event of a system fault.

Further, 19 is a closing coil of the breaker, 96 is a pneumatic contact that closes when the operating air pressure of the breaker is normal, and P and N are DC operating busbars.

The operation of FIG. 6 will be explained with reference to FIG. 7 as follows.

Contact 23-1 closes at time t2 when the voltage-free time has elapsed from fault removal time t1.

At this time, if there is no accident in the system and the reclosing conditions are satisfied,
Since the contacts 24-1 and 25 are both closed, the auxiliary relay 20 is energized and self-maintained by the contact 20-1, and the auxiliary relay 21 is energized by the contact 20-2.

The auxiliary relay 21 is self-held by the contact 21-2, and at the same time, the closing coil 19 is turned on by the contact 21-1 at time t21.
is excited, and if the air pressure is normal, the contact 96 is closed, so the circuit breaker is closed at time t4.

Further, the contact 21-1, in parallel with the closing coil 19, excites the auxiliary relay 18 at time t21, and opens the normally closed contact 18-1 (FIG. 4) of the auxiliary relay 18 at time t3.

At the time of this opening, the phase comparison relay 7 on the power supply end side is not outputting (until time t4 when the circuit breaker 4 is turned on again, the current at its own end is zero, and it outputs "OA &level" which corresponds to the continuous F1 signal. do.

) Therefore, the carrier sent from the power supply end immediately becomes a continuous F1 signal and is received by the variable current end at time t31 after the transmission delay time Td.

Upon reception of this F1 signal, the phase comparison relay 7 at the variable power supply end shifts to the recovery state and becomes completely inoperable at time t5.

Regarding the carrier sent out from the variable power supply terminal, the F2 signal is continuous until time t4 when the breaker 4 is turned on, regardless of whether the contact 18-1 (Fig. 4) is opened (the current is zero when the breaker is opened). At this time, the variable power supply terminal outputs a level corresponding to the F2 signal.

). After time t4, it is determined by the input current.

In the above description of FIG. 7, it is assumed that all other operations except for the operation of the phase comparison relay 7 are substantially the same at both terminals, and that the sequences at both terminals proceed substantially simultaneously.

As is clear from this figure, on the variable power supply end side (Fig. 7 I), the recovery time 15 of the phase comparison relay (t1 hours after the time t2 after the no-voltage period has elapsed) is the breaker closing time t4 ( From time t2 to t.

hours later).

Incidentally, the operating time of the auxiliary relays 18, 20, and 21 is approximately 15 (m5ec), the operating time of the closing coil 19 is approximately 30 to 40 (mSeC), and the transmission delay time is approximately 5 (m5ec).
5eC), the recovery time of the phase comparison relay 7 is approximately 20 (ms
ec), To and T1 are respectively 60 to 70 (mS
ec), about 70 (m5eC).

This did not pose any problem in the conventional phase comparison relay device described above.

In other words, in the first case, if there is no internal fault when the breaker is turned on at time t4, the undervoltage relay in the tripping circuit shown in Figure 3 is inoperable and contact 16 is open. Because there is, there is no need to cut it off again.G)

In the second case, if there is an internal fault at time t4, a tripping signal can be instantaneously provided by the operation of the undervoltage relay, which is rather convenient for high-speed operation.

As a third case, when an external accident occurs at time t4, it is possible that the circuit will be erroneously cut off and the re-closing will fail, but this is almost impossible in practice.

That is, in FIG. 6, the excitation of the closing coil 19 of the breaker is caused by the contact 25 without any accident (the contact 25 is that of an undervoltage relay).

) has been confirmed, and it is impossible as an accident phenomenon that there is no accident at time t2 and an external accident occurs by 14 immediately after that.

In this way, follow-up accidents like the third case (two or more accidents occur in succession), and the time of the second occurrence is a very limited and short time in the relay sequence, etc. Since this phenomenon never occurs, it was thought that the conventional phase comparison relay device was completely reliable in terms of reclosing operation.

However, this is the first time that it has been revealed that a third case like this occurs.

This is the erroneous disconnection of Line 1 during the single-blade line arc accident and permanent line 2 accident mentioned above, and the line 1 reclosing failure occurs due to voltage drop due to the permanent fault occurring during double line reclosing. .

Such a case is virtually unprecedented, and it was impossible to imagine that there would be a case where the problem would surface by reclosing the circuit.

The present invention aims to take measures against this problem, and the seventh
As is clear from the time diagram in the figure, in the conventional method, T1>To
Therefore, the arc fault line will be shut off again.

From the above explanation, it would be better to restore the phase comparison relay, which operates at the LL level and is treated as a variable power supply terminal, a little earlier.

To this end, the breaker on the phase comparison relay side, which operates at the LH level and is treated as a power source end, should be turned on early.

For example, if the no-voltage time on the power supply end is set shorter than that on the variable power supply end, the phase comparison relay 7 on the variable power supply end can be reset before the breaker on the variable power supply end is turned on. good.

However, in recent years, phase comparison relays installed in ultra-high voltage systems or ultra-super high voltage systems often have two series as shown in Figure 5, and in series A, electric station A is treated as the power source end, and electric station B is treated as the variable power source. In the B series, unlike the A series, electric station A is treated as the variable power source end, and electric station B is treated as the power source, so phase comparison relays that operate at the LL level will be installed at both electric stations. Therefore, it is no longer possible to take measures by making a difference in the no-voltage time.

The conveyance control circuit of the present invention will be explained below using FIG. 8. The difference from the circuit in FIG. 4 is that the contact 1 in FIG.
The first point is that the conveyance control that used to be performed by the series circuit of contacts 17 and 18-1 is now performed by the series circuit of contacts 17 and 27-2. This is what we have set up.

First, considering the first point, the contact 17 is closed when the breaker is opened, and the normally closed contact 2T-2 of the auxiliary relay 2γ shown in FIG. Open before opening the vessel.

Therefore, when performing a normal reclosing operation, contacts 17 and 27-2 are not both closed.

As will be described later, these two contacts 17 and 27-2 are used to provide a continuous F2 signal in the event of an internal accident when the circuit is not reclosed (in other words, during charging operation from one end as described above). belongs to.

When the circuit is not reclosed, the contact 26 shown in FIG. 6, which is closed when reclosing is allowed, is open, and the auxiliary relay 21 is inoperative.

Therefore, when the circuit is not reclosed, only the contact 17 is driven and closes in FIG. 8, sending out a continuous F2 signal.

Therefore, when performing the recirculation operation which is a problem in the present invention, it is only necessary to consider the contact 28-1, and the contact 28-1 is driven by the auxiliary relay 28 shown in FIG.
is driven by contact TC-1 of tripping coil TC.

In this way, the contact 28-1 is activated during the period in which the breaker tripping command exists, that is, the disconnection command in Figure 3 is established (contact 7
-a and 16 are both closed), then the pallet switch PS is opened by opening the breaker, and the trip coil T
It opens and closes until the excitation of C is released.

That is, time t in FIG.

2, the contact 28-1 at each own end is closed, and the transmission carrier at the own end becomes a continuous F2 signal.

This is the return time t1 of the auxiliary relay 28 after opening the breaker.
□ (FIG. 7 CI), (This period of the ID sending or receiving carrier is shown with diagonal lines.

), and from time t1 onwards, first, the power source terminal sends out a continuous F1 signal as shown by the dotted line.

In other words, in FIG. 8, after 11, the breaker is open and the current is zero, so the rectangular wave shaping circuit 8 has g(0
1 level signal is given, contacts 2T-2 and 28-1 are open (contact 27-2 is continuously energized and remains open at least during the non-voltage time of the auxiliary relay 27 in Fig. 6, and contact 28-2 is open). 1 is released at time t11.

), so the F1 signal is given.

This signal is received at the variable power supply end after a transmission delay time and causes the phase comparison relay to return to normal.

Regarding the carrier sent out from the variable power supply terminal, t is due to the same reason as above.

A continuous F2 signal is generated between 1 and 11.

However, after 11, the current is zero due to the opening of the breaker, so the rectangular wave shaping circuit 8 provides a level output of 11 corresponding to the F2 signal.

According to the present invention, continuous F2 signals are given to each other during the period when the cutoff command is being outputted, but this is intended to make it easier to close the breaker, and this does not become a hindrance.

In the present invention, the coil of contact 28-1 itself is deenergized by the pallet switch of the breaker, so the time from when it is energized by the cutoff command to when it is de-energized as shown in Figure 3, that is, when contact 28-1 is closed, is The time spent is looms
That's about it.

Comparing Fig. 4 and Fig. 8, conventionally, the time from when the breaker is opened and the contact 17 is closed until the re-closing command is issued and 18-1 is activated, that is, the re-closing no-voltage period, the trip continues. Although the permission signal (F2 signal) was being sent,
According to the present invention, the loo where the breaker command is issued
The continuous F2 signal is transmitted only for a time of about ms, that is, while the contact 28-1 is closed.

Next, consider when the contact 28-1 opens at time hl. At the power supply end, the carrier to be sent out is a continuous F1 signal as shown by the dotted line (one input of the OR circuit OR in Figure 8 is By opening contacts 27-2 and 28-1, "'0°
The rectangular wave shaping circuit 8 inputs zero current and outputs 11011 in order to open the breaker at its own end.

). This continuous F signal is received at the multiplier signal variable power supply terminal, and the phase comparison relay 7 is reset.

After t11, the time it takes for the phase comparison relay 7 at the variable power source end to actually recover is over 100 msec, and it has completely recovered by the time the breaker is turned on again at time t4.

Therefore, even in the case of an arcing accident on the own line or a permanent accident on the adjacent line as shown in FIG. 3, there will be no possibility of erroneous re-closing failure.

Incidentally, considering the operation of the variable power supply terminal shown in FIG. 8 after t11, the rectangular wave shaping circuit 8 inputs zero current to open the breaker at its own terminal and outputs "1", and the contact 21-2 The continuous F2 signal continues to be output regardless of whether the F2 signal is opened or not.

The phase comparison relay 7 at the power supply end receives the continuous F2 signal, but is inactive because it generates the continuous F1 signal at its own end.

In FIG. 6, the contacts 27-1 and the like are opened as appropriate after the circuit is turned on again, and the circuit in FIG. 6 is restored.

In other words, the present invention replaces the conventional method of transmitting a continuous F2 signal as shown in Fig. 4 until the breaker is closed by re-closing after opening the breaker. It is characterized in that a continuous F2 signal is transmitted only for a certain period of time.

Of course, when the power transmission line is being charged only from terminals that are treated as variable power supply terminals, it is necessary that the phase comparison relay can be shut off at high speed even if an internal accident occurs. In the purlin embodiment, the continuous F2 signal is transmitted under the AND condition of 27-2 and no operation.

That is, when the power transmission line is being charged from only one end, the contact 26 of the reclosing circuit shown in FIG. If the breaker operates with the breaker open, 17 is closed and a continuous F9 signal can be transmitted, so even if the continuous F2 signal is transmitted only in response to a relay cutoff command from the protective relay device as in the present invention, there is no problem with the conventional method. There is no risk of damaging the original functions.

In order to realize the present invention, it is necessary to consider the following matter.

Conventionally, the continuous F2 signal transmitted during the reclosing no-voltage time is used to find the phase of the opposite end, and the reclosing condition, for example 2, is detected.
Although two-phase interconnection is detected in the total number of lines, in the method according to the present invention, when the reclosing circuit shown in Fig. 6 is activated, continuous F2 signals are transmitted only when a cutoff command is issued, so When the F2 signal is received, it becomes necessary to determine the breaker at the other end and maintain that condition.

However, this can be realized very easily as shown in FIG.

Figure 9 shows a circuit provided for each phase to detect that the carrier from the other end is a continuous F2 signal. The normally closed contact of the auxiliary relay 21 (see FIG. 6) is operated, and 31 is the normally closed contact of the auxiliary relay that operates at final cutoff (cutoff due to failure of reclosing).

32 is an auxiliary relay (
29-a is a normally open contact of the auxiliary relay 2 (not shown).
9 self-holding contacts.

With this circuit, FIG.

The continuous F2 signal between 2'' and 11 is stored until reclosed.

FIG. 9a shows that this circuit is used to confirm that there is interconnection of two or more phases in total for two lines.

29-1.29-2. 29-3 are normally closed contacts of the A-phase, B-phase, and C-phase of the auxiliary relay 29 shown in the figure, which operate by detecting the continuous F2 signal from the other end of the own line, respectively, and 29'-L
The 1 (dash) in 29'-2 and 29'-3 is the A phase of the auxiliary relay 29' (not shown) which similarly operates by detecting the continuous F2 signal from the other end of the adjacent line. , B phase,
This is a C-phase normally closed contact.

30-1, 30-2. 30-3 is not shown, but is a normally closed contact 30' of an auxiliary relay for each phase that operates simultaneously with a cutoff command at its own line and is self-maintained until re-on or final cutoff. -1, 30'-2, and 30'-3 perform the same operation at the end of the adjacent line.

According to this circuit, a continuous F2 signal cannot be obtained before the accident occurs, the auxiliary relay 29 is inoperative, and the contacts 29,
29' is closed.

Furthermore, contacts 30° and 30' were also closed before the accident occurred.

As a result, all the contacts shown in FIG. 9a are closed and the auxiliary relay 24 is in an energized state.

These contacts are opened by removing the breaker row as described above, and are maintained in the open state until the re-closing is completed.

In this circuit, two sets of series contacts with a dash or two sets of series contacts without a dash represent the open/close state of that phase of the line, for example contacts 29'-2, 3.
The fact that the series circuit of σ-2 is open means that the adjacent line B
This means that the phase breaker is open.

Then, the six sets of contacts (29-3, 3
0-3,29'-L3σ-1,29'-2,3σ-2)
In a circuit configured as follows, ``the own line C phase is interconnected, and at least one of the adjacent line A phase or C phase is interconnected.

” holds true and energizes the auxiliary relay 24.

Similarly, the six contact groups on the center and left side are
The phases are interconnected, and at least one of the adjacent line phase or C phase is interconnected.

"The own line A phase is interconnected, and at least one of the adjacent line B phase or C phase is interconnected."

This is to confirm that

It has been confirmed that each of these 6 contact groups has 2-phase interconnection for a total of 2 circuits, and according to the overall configuration shown in Figure 9a, 2
This means that 2 or more sets of interconnected lines in total are detected.

Output contact 24-1 of auxiliary relay 24 is used in the reclosing circuit of FIG. 6 to prevent breaker reclosing when two-phase interconnection is not confirmed.

That is, when the interconnection of two or more sets is not confirmed, the auxiliary relay 24 returns and the sixth fixed contact 24-1 is opened.

[Brief explanation of drawings]

Figure 1 is a diagram explaining the principle of the phase comparison transport protection relay system, Figure 2
The figure is a diagram explaining the reaction under various conditions of the same system, Figure 3 is a diagram explaining problems in the conventional system, Figure 4 is a conventional conveyance control circuit diagram, and Figure 5 is a diagram of a two-line phase comparison conveyance protection relay system. , FIG. 6 is a conventional reclosing circuit control circuit diagram, FIG. 7 is a time diagram showing its operation, and FIGS. 8 and 9 are circuit diagrams of a phase comparison transport protection system according to the present invention. 4... Breaker, 5... Power transmission line, 6...
...Relay input current, T...Phase comparison relay, 8...Square wave shaping circuit, 9...---
Coincidence circuit, 10...Integrator circuit, 11...
・Output circuit, 12... Information transmission device, 13...
...Transmitter, 14...Receiver, 15...
. . . Microwave line, 29 . . . Auxiliary relay that memorizes the distance between the breaker at the other end, 28 . . . Contact that opens for a short time in response to a breaker command.

Claims (1)

[Claims] Applied to a power transmission line with a 12-line configuration, the current of the transmission line is detected for each phase at each terminal of the transmission line, and when the current passing through the transmission line is viewed as having the same polarity at each terminal, phase comparison is performed as if it were treated as a power supply terminal. The relay sends a phase signal to the other end that allows tripping during a period when the current is above a predetermined current level and does not include zero current, and prohibits tripping during other periods, and the phase comparison relay, which is treated as a variable power supply end, and sends a phase signal to the other end that allows tripping during a period including zero current and prohibits tripping during other periods, and sends a continuous phase signal that allows tripping to the other end at the open terminal of the breaker, At each terminal, the phase comparison relay at its own end determines whether the phase signal at its own end matches the trip permissible part of the phase signal at the other end and outputs the same, when it detects a drop in the line voltage at its own end and detects a lack of electrons. The fact that the relay is also outputting opens the circuit breaker at its own end, and when the transmission line is reclosed, it sends a message from the other end that at least two phases of interconnection are maintained between the two transmission lines. In the phase comparison transfer protective relay method, which uses continuous trip-permitted phase signals received by the breaker and makes the breaker reclosing circuit unidirectional, at the power supply end, the period during which the disconnection command is given to the self-terminated breaker transmits a continuous trip-permitted phase signal from its own end, and at least at the variable power supply end, the above-mentioned two-phase interconnection is confirmed from the received continuous trip-permitted signal, and this is determined whether the breaker is closed by re-closing or the final A phase comparison transfer protection relay system characterized by storing up to cutoff and using the stored signal as a condition for two-phase interconnection.