JPS588652B2 - High quality and high quality materials. - Google Patents

Description

[Detailed description of the invention] The present invention relates to a ground fault recovery device for a multi-circuit distribution line.

As a ground fault protection method in a distribution substation with multi-circuit distribution lines, normally ground fault direction relays RY-1 to RY-5 are provided for each line F1 to F5 as shown in Figure 1, and the detection signal is used to shut off the ground fault. CB-1 to CB-5 are selectively cut off to disconnect the faulty line.

However, in the case of a so-called micro-ground fault, the zero-sequence voltage and current do not reach a value sufficient for the operation of the ground-fault directional relay, making it impossible to selectively shut off the relay, and if left as is and the fault continues for a long time, it can lead to personal injury. or cause danger to property, etc.

For this reason, conventionally, as shown in Figure 1, the zero-sequence voltage Vo that occurs when a slight ground fault occurs is detected by a meter M, and maintenance personnel sequentially cut off and turn on the first to fifth circuits F1 to F5 while looking at it. During this process, for example, when the fourth line F4 is cut off, the zero-phase voltage Vo disappears, and this line F4 is determined to be a faulty line.

In this case, since the maintenance personnel's judgment is involved, erroneous judgments and erroneous operations occur, and the process is not necessarily carried out reliably, and there have been reports of cases in which this has led to personal accidents.

In order to eliminate such defects, there is provided a voltage detection device for detecting a ground fault in a distribution line, and a timer that starts based on a signal detected from the device and determines that the ground fault has continued for a certain period of time. A cutoff stepping device operates according to a signal from the timer to sequentially cut off the distribution lines and memorize the faulty line, and a recovery signal from the voltage detection device generated when the faulty line is cut off by the stepping device sequentially cuts the distribution line. A distribution line ground fault selection device is disclosed in the patent application filed in 1972, which is comprised of a closing step device that gives a closing command up to one line before the memory failure line.
It is proposed as No.-108173.

According to this known example, automatic detection of a failed line is possible, but no consideration is given to automatic recovery control.

However, in operation, when the device completes its operational duties, the re-closing devices are all unlocked (before the device starts operating, the re-closing devices are all locked for each line).

), it is possible to automatically restore a failed line, but in the case of multiple line failures, automatic recovery will be required all at once.

At this time, there is no particular problem if the fault has been recovered, but if the fault continues, there is a drawback that it becomes impossible to identify the faulty line or detect the section.

Furthermore, in the known example, since the system uses its own device to issue a re-opening command to the trial open circuits excluding the faulty line, this re-closing command and the re-closing command from the re-closing device installed in each line are different. In order to avoid mismatch, it is necessary to apply a starting lock to the re-closing device for each circuit as described above, and therefore it is not possible to immediately perform the re-closing operation in response to a failure other than a slight ground fault.

Moreover, since it requires a charging step device, it has the disadvantage that the device configuration is complicated.

The present invention has been proposed in view of the above points, and it simplifies the configuration by providing this function to the existing reclosing device without providing the closing step device in the known example, and in the case of multiple failures, The distribution lines are sequentially disconnected from the lowest priority, and the circuits where the fault has disappeared (i.e. faulty circuits) are memorized from the highest priority, and then the faulty circuits with the highest priority are automatically restored in order, and one faulty circuit is re-closed. It is an object of the present invention to eliminate the above-mentioned drawbacks by configuring the system to wait for the end of the operation of the device before automatically restoring the next failed line.

The present invention will be explained below. FIG. 2 is a block diagram showing one embodiment of the present invention, where R is a ground voltage detection device, and a contact that closes when the zero-sequence voltage Vo occurs exceeds a predetermined level and continues for a certain period of time, and a contact that closes immediately. It has a contact point.

H is a stepping device that advances in response to the output of device R, and J is a stepping device that sequentially locks the activation of the re-closing devices 79-1 to 79-5 until the highest fault line is cut off by the stepping device H. A locking and unlocking device for unlocking the circuit closing device, K is connected to the circuit breaker CB-1 by the stepping device H.
~C A cutoff command device that sequentially gives a cutoff command to B-5, P releases the activation lock of the reclosing devices 79-1-79-5 sequentially from the highest rank after storing the cutoff of all failed lines and restores the failed line. This is a failed line storage recovery device that allows

FIG. 3 is a circuit connection diagram showing a specific embodiment of each device shown in FIG. 2.

In the figure, RYX is a reception auxiliary relay that operates when contact R-1 of the ground fault detection device R is closed, SY is a restart relay, and T1 is a first timer for measuring restart time (the time limit is e.g. 140 seconds or 200 seconds). ), both of which are in the stepping device H.

S is a reclosing lock detection relay in the locking and unlocking device J, STP is a stepping pulse forming relay, T2 is a second timer for determining the stepping interval (the time limit is, for example, 1 to 5 seconds),
STL is a stepping pulse cutting relay, RSX is a stepping auxiliary relay, C is a charge storage capacitor, and RS is a stepping relay, all of which are in the stepping device H.

1L to 5L are re-closing activation locks and fault line memory relays, and N is a memory line selection relay, both of which are in the fault line memory restoration device P.

X is a relay for forming a cutoff command, T4 is a fourth timer for forming a cutoff command (time limit is, for example, 0.5 to 1 second), and Y is an auxiliary relay for a cutoff command, all of which are in the cutoff command device K.

RS-1 to RS-5 are mutually interlocked rotors that move one step by energization of relay RS, and RS-N
Once relay RS is energized, the rotor goes through one cycle and zero
Closed contact during startup, RS-, which is closed when returning to position.
i is an interrupter contact that opens every time relay RS is energized.

Note that FIG. 3 shows an example of a relay constructed of contact relays, and the contacts of each relay are shown with the same reference numerals as those of the contact relay followed by a number.

The white circle contacts represent closed contacts during operation, and the black circle contacts represent open contacts during operation.

Furthermore, it is needless to say that the structure is not limited to a contact relay, but may be constructed of a static circuit such as a logic circuit.

Next, the operation will be explained in detail with reference to the time chart shown in FIG.

In order to facilitate understanding, symbols (i to wa) indicating the positions of relays, contacts, etc. in FIG. 3 are added.

Now, of the 1st to 5th lines in Figure 2, the 4th line F4 and the 5th line
Consider the case where a slight ground fault occurs in line F5.

Since the zero-phase voltage V0 appears due to the occurrence of the fault, this is detected by the ground voltage detection device R, and when it exceeds a predetermined level and continues for a predetermined period of time, the contact R-1a is closed and the relay RYXa is operated.

Then, the contact RyX12 closes, so the relay STP2 operates and closes the contact STP-1.

Therefore, the relay RS is temporarily energized by the accumulated charge of the capacitor C, and the rotors RS-1 to RS5 are
W moves one step from the 0 position to the 1 position, and at the same time, the contacts RS-N and H are closed, and the relay RSX and H is operated.

Due to the above step, relay 1L-chi operates and its contact 1L-
Self-holding is performed by 1-ch, and the contacts 1L1L-2 are closed to prepare for return.

Also, contacts 1L-5O are opened to lock activation of re-closing device 79-1O.

Due to the above operation of the relay RSX, its contact RSX-4 closes and the relay be separated.

Due to the operation of relay The cutoff command is cut off when the circuit is opened by 1W.

That is, a cutoff command for a certain period of time t4 is generated.

Due to the operation of relay RSX, contact RSX-t2 is opened and relay STP is restored.

On the other hand, when the contact RSX-2 is closed, the timer T2-2 starts measuring time, and after a predetermined time period, the contacts T2-1-2 and T2-2-2 are closed.

As a result, the relay STP operates and its contact STP-2
d operates relay STL d, so its contact ST
The relay STP and timer T2 are reset when L-1-ro is opened.

Thereafter, this operation is repeated and the relay STP operates at the time interval of the timer T2, and each time the relay RS is energized and the rotors RS-1 to RS5 advance by one step.

When the rotor RS-1 steps from the 1st position to the 2nd position, the relay 1L is short-circuited through the contacts IL-1 and IL-2 and returns to its original state.

Accordingly, the contact 1L-5 is closed, the lock is released, and the re-closing device 79-1 starts to operate.

The operation of the relay 2L-1 opens the contact 2L-5O, locking the activation of the re-closing device 79-2O, and the operation of the relay X closes the contact 2L-5O.

The disconnection command is given to the disconnector CB-2, and the second line F2 in FIG. 2 is disconnected, as in the case of the first line, and this operation is repeated thereafter.

When the rotor advances to the fourth step, the reclosing device 7
9-3O is activated, 79-4O is activated and locked, and circuit breaker CB-4W is cut off.

However, even if the fourth line F4 is disconnected, the zero-phase voltage Vo still remains generated because the fifth line F5 also has a ground fault.

Therefore, in the same manner as above, the fifth step is reached, where the reclosing device 79-4 is activated, the re-closing device 79-5 is activated and the circuit breaker CB-5 is disconnected, and the entire ground fault circuit is disconnected for the first time, so the zero-phase voltage is lost and relay RYX is restored by opening contact R-1.

Therefore, the relays STP, STL, and timer T2 stop operating, and each rotor stands still at the 5th position.

When a failure occurs, relay RSX operates, its contact RSX-2 closes, and relay SY port operates, so timer T1
B starts timing almost at the same time as the failure occurs, but when it reaches the predetermined time limit t1, it closes the contact T1-1,
Relay RS is energized on condition that relay RSX is operating.

Therefore, each rotor advances one step from the 5th position to the 6th position.

However, since relay RYX has already been restored, relay 5L will not be restored.

The moment the RS rotor advances one step, contact RS-
i opens and de-energizes RS, which causes RS-
i is closed again.

Thereafter, the contact RS-i repeats opening and closing every time the relay RS is energized, thereby causing each rotor to advance by itself.

Furthermore, while the relay RS is self-stepping, the timer T1 is operating, so the relay X is not operating, and therefore a cutoff command is not given.

When each rotor completes one round of operation and returns to the 0 position, the relay RSX returns to reset the timer T1.

The above-mentioned one-cycle operation relay power switch 4L returns, and the re-closing device 7
The circuit breaker CB-4 is reclosed by 9-4, but if this is successful, no zero-sequence voltage Vo is generated.

However, if this is unsuccessful and the ground fault continues, the zero-sequence voltage Vo appears again and the device R operates.

Therefore, the rotor starts the second round in the same way as the first round, and repeats the re-closing start lock, the line cutoff, and the unlocking, until the fourth line is reached.

When the relay 4L operates, the breaker CB-4 is cut off and the faulty line F4 is disconnected, so the zero-sequence voltage V0
is lost and relay RYX is restored.

Each rotor stops at position 4, but as in the case of the first round, waits for the timer T1 to finish counting, advances by itself, and returns to position 0.

Therefore, relay RSX is restored and relay 4L remains in operation.

During the self-stepping, the timer T1 is operating as in the first round, so the relay X does not operate, and therefore a cutoff command is not given.

When each rotor returns to the 0 position, the relay RSX timer T1 returns.

Therefore, relays RYX and RSX are restored, and relay 4L (5L
) Under the condition of operation, the relay S is operated and is self-held by its contact S-2, and the relay RS is energized by its contact S-3.

Therefore, the rotor starts the third round of advancement, but the relay R
Since YX has returned and relay S is operating, rotor R
The circuit via S-1 is not established, and the relays 1L to 3L do not operate.

When the rotor RS-3 reaches the 1 position, the relay N is activated under the condition that the relays 5L and 5S are operated, and is self-held by its contact N-1.

For this reason, contacts S-5, N-2, S-6, rotor RS
-2, contacts 5L-2 and 5L-1 are both short-circuited and returned to normal state by short-circuiting the relay 5L and releasing the activation lock, so that the re-closing device 79-5o is activated.

After a certain period of time, the device 79-5 issues a reclose command to the breaker CB-5 to perform failure processing.

When reclosing is performed, if the ground fault still continues and zero-sequence voltage Vo is detected by device R, the contact R
-2 immediately closes, operating relay X on the condition that relay N operates.

Therefore, a disconnection command is given to the circuit breaker CB-5 via the rotor RS-5, and the failed line F5 (FIG. 2) is permanently disconnected.

When the time t1 necessary for the failure processing has elapsed, the timer T
1 operates to restore relay N.

Therefore, the relay RS is energized via the contacts S-3 and N-4, and each rotor advances from the 1st position to the 2nd position.

Here, on the condition that relay 4L is operating, relay N
or operates again to stop the rotor at that position.

As in the case described above, the relay 4L is short-circuited, the activation lock of the re-closing device 79-4 is released, and the circuit breaker CB-
4 is reclosed.

Therefore, the re-closing device 79-4 performs failure recovery processing on the line F4, and power is supplied to the healthy section.

If the fault has not been recovered, the circuit breaker CB-4 is activated by a command via the rotor RS-5 as in the case of the fifth line.
will be permanently cut off.

When the time limit required for this process ends, timer T1 operates to restore relay N.

Therefore, relay RS is energized via contacts S-3 and N-4, and each rotor self-progresses.

In the 3rd, 4th, and 5th steps, since the relays 3L to 1L are inoperative, each rotor continues to advance on its own and returns to the 0 position, completing the third round.

Accordingly, the device returns to its original state, and a series of failure detection and recovery processes are completed.

Although the case where a ground fault occurs in two lines has been described above, failures in three or more lines can be handled in the same way.

In that case, each rotor makes three rounds to detect the faulty line,
It makes one round for recovery processing.

If only one line is out of order, the rotor makes one round to detect the failed line, and then immediately moves on to the final round of recovery processing.

Although this embodiment has been described above for a five-line distribution line, it is of course applicable to a case of n-line distribution lines.

As described above, according to the present invention, when multiple faults occur in a power distribution line having multiple circuits, the higher the fault line to which the heavy load is connected, the earlier it is detected and cut off, and the activation of the re-closing device is locked and memorized. The system is configured so that when the lock is released from the high-rank faulty line and the processing for one faulty line is completed, the process is transferred to the next high-rank faulty line, so the existing re-closing device can be used as is to connect the important load. Automatic recovery is possible in the event of multiple line failures with less power outage time, and even if failures continue, recovery processing can be performed quickly without any problems such as errors in identifying failed lines or detecting failed sections. It has the advantage that it can be carried out.

Furthermore, in the present invention, since the re-closing is carried out using the existing re-closing device, there is no intertwining between the closing step device and the re-closing device as in known examples, and there is no need to provide a collective locking device for the existing re-closing device. In addition, the breaker closing operation can be simplified and unified, the configuration can be simplified, and furthermore, it has the remarkable effect of being able to immediately respond to failures and disconnections other than slight ground faults.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a power distribution substation, FIG. 2 is a block diagram showing one embodiment of the present invention, and FIG. 3 is a specific circuit connection diagram showing one embodiment of the present invention. is a reception auxiliary circuit, B is a restart time measurement circuit, C is a re-closing lock detection circuit, D is a stepping pulse generation circuit, E is a signal generation circuit during stepping, F is a stepping circuit, G is a self-stepping Circuit, H is the reclosing start lock and fault line memory circuit, R is the memory release circuit, N is the memorized line selection circuit, L is the cutoff command generation circuit, O is the reclosing start lock command sending circuit, and W is the cutoff command sending circuit. It is. FIG. 4 shows a time chart for explaining the operation of the one shown in FIG. 3, where A shows the case of the first round of the rotor, and B shows the cases of the second and third round, respectively. F1 to F5... Distribution line, CB-1 to CB-5.
...Shin analyzer, 79-1 to 79-5...
Reclosing device, R...Ground voltage detection device, H...
... Stepping device, J... Song reclosure start lock and lock release device, K... Cutoff command device, P...
...Failure line memory recovery device.

Claims (1)

[Claims] 1. A reclosing device installed in each circuit of the distribution line, a ground fault voltage detection device for detecting a ground fault fault in the distribution line, and a step based on the signal detected by this ground fault voltage detection device. A stepper device, a cutoff command device that receives the output of the stepper device and sequentially issues a cutoff command to the circuit breaker of each line, which sequentially locks the activation of the reclosing device starting with the lower priority line and then cuts off that line. A locking and unlocking device that releases the activation lock of the reclosing device of the preceding line every time one line increments, detects the highest ranking of the faulty circuits, and performs an operation to continue the activation lock of the reclosing device. All failed circuits are detected and memorized by repeating the number of failed circuits, and then the activation lock of the re-closing device is released in sequence starting from the highest-ranked failed circuit, and after waiting for the operation of the re-closing device of one failed circuit to be completed, the next one is detected. A ground fault recovery device for a multi-circuit distribution line, comprising a fault line storage recovery device for automatic recovery of a fault line.