JPS6341173B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for monitoring the opening/closing status of an electric station busbar switch.

Generally, a power transmission line at an electric station can be connected to any of the dual busbars via a switch. For this switch, it is necessary to know to which bus the power transmission line is connected, for example for the purpose of synchronization verification. As a monitoring device for this purpose, the one shown in FIG. 1 is known. First, Figure b shows the electrical station busbar configuration, where the transmission line L has a circuit breaker CB and a switch LSA.
Or bus BA or bus BB via LSB
It is connected to the. The monitoring circuit in figure a is the power supply PN.
provided in between. 1a and 1b are the normally open and normally closed contacts of switch LSA, and 2a and 2b are switch LSB.
Normally open and normally closed contacts. 1a and 2b are connected in series to excite the first coil 11C of the keep relay 11, and the contacts 1a and 2a excite the second coil 11R. A keep relay has a mechanical holding mechanism. For example, after the first coil is energized, the keep relay remains in place until the second coil is energized.
The state of output contact 1 does not change. The keep relay 11 closes the contact 11a by excitation of 11C.
Open 1b. At this time, the switch means that the LSA is closed. Conversely, when 11R is excited, 11a opens and 11b closes, causing the switch to close.
Means LSB is closed. When operating the busbar, two sets of switches may be opened or closed together, but in either case, the output contact of the keep relay maintains the output before the state change. This does not cause any problems. When both sets are closed, they are operated as one bus bar, so either one may be selected. On the other hand, when both are open, it is out of operation and there is no point in detecting it.
Note that when a switch is connected to one bus bar, the keep relay shifts to the open/close state of a new switch.

The mechanical holding characteristics of the keep relay should be satisfactory in the above sense, but if the power supply PN is disconnected for some reason, it will not be able to follow any changes in the open/close state of the switch. Here, a power outage does not only mean the loss of the power supply itself, but also includes the opening of a breaker or fuse, or a poor connection, and it must be said that the probability of such occurrence is quite high. As a method of detecting this power outage, it is sufficient to monitor the voltage between the power supply PN, but contacts 1 and 2 are provided close to the bus switch, and the keep relay 11 is
It is installed in an operation room 100 (M) away, and the power supply is divided for each transmission line, and the equipment shown in Figure 1a is installed, so it is not possible to arrange cables and monitor the voltage for all of them. It is virtually impossible.
It is also possible to monitor using the current from the power supply, but 2
When both switches in a set are open and closed, no current flows to the keep relay and detection is impossible.

In view of the above, an object of the present invention is to provide a busbar switch state detection device that can accurately reflect the open/closed state of the switch and can detect a power-off state.

FIG. 2 shows the first embodiment of the present invention, and the contact 1
a, 1b, 2a, and 2b are arranged as shown.
The auxiliary relays 8 and 9 do not have a mechanical holding force like the above-mentioned keep relays, and operate only when receiving excitation input, closing the normally open contacts 8a and 9a and opening the normally closed contacts 8b and 9b. . In the system shown in FIG. 2, the operation of auxiliary relay 8 represents the closing of switch LSA, and the operation of auxiliary relay 9 represents the closing of switch LSB. As shown in the figure, the auxiliary relay 8 is energized when the contact 1a is closed or when both 1a and 2b are closed. In other words, when switch LSA is closed, or when switches LSA and LSB are both open,
This indicates that the switch LSA is determined to be closed. Auxiliary relay 9 has contacts 1b and 2
It works when a is closed. This is switch LSA
When the switch LSB is open and the switch LSB is closed, it means that it is determined that the switch LSB is closed. PA and NA are power supplies separate from P and N, and the auxiliary relay 10 detects the loss of the power supplies P and N through a combination of contacts 8a, 8b, 9a, and 9b.

Figure 3b shows the state of each part when both switches LSA and LSB are open, and contacts 1a,
2a is open and contacts 1b and 2b are closed. At this time, the current flows through the route P-1b-2b-8-N, and the auxiliary relay 8 becomes operational, indicating that the switch LSA is closed as promised in advance. Auxiliary relay 9 has no circuit formed and is inoperative.
By the operation of 8 and 9, 8a and 9b are closed and 8b and 9a are opened, so that the auxiliary relay 10
is inactive and does not indicate a power failure. When the power supplies P and N are disconnected in this state, the auxiliary relay 8 is demagnetized, 8a opens, and 8b closes, so the auxiliary relay 10 indicates that the power supplies P and N are disconnected. In addition, when the power is cut off, the auxiliary relay 8 returns and the switch is activated.
The LSA closure detection output will be lost.

Figure 3b shows a case where the switch LSA is closed and LSB is open, and the contacts 1a and 2b are closed and the contacts 1b and 2a are closed.
is opened, the auxiliary relay 8 is energized by the circuit P-1a-8-N, and the closing of the switch LSA is indicated. Auxiliary relay 9 has no circuit formed and is inoperative. As can be understood from the above, auxiliary relay 10 is energized only when auxiliary relays 8 and 9 are both energized or demagnetized, so only auxiliary relay 8 is energized as in this case. It does not output when Auxiliary relay 8 without mechanical holding function due to disconnection of power supply P-N
returns, energizes the auxiliary relay 10 by the circuit PA-8b-9b-10-NA, and indicates an abnormality in the power supply P-N.

FIG. 3c shows a case where the switch LSA is open and LSB is closed, and the contacts 1b and 2a are closed and the contacts 1a and 2b are open. Although the auxiliary relay 9 is excited by the circuit P-1b-2a-9-N, the excitation circuit for the auxiliary relay 8 is not formed. Switch by operation of 9
LSB closing is output, and at this time auxiliary relay 8
is not operating, so the auxiliary relay 10 is not operating. If the power supply PN is cut off in this state, a state similar to that shown in FIG. 3b will occur, and this will be displayed by the auxiliary relay 10.

Finally, the case where both switches LSA and LSB are closed will be explained using FIG. 3d. Since contacts 1a and 2a are closed and contacts 2b and 1b are open, only the circuit P-1a-8-N is formed.
Only auxiliary relay 8 operates, and as promised, the switch
Display as LSA closed. In this case, as in the previous case, the auxiliary relay 10 is not energized, and when the power supply PN is turned off, the auxiliary relays 8 and 9 are reset and this is displayed.

As described above, in all cases, the correct open/close state of the switch can be displayed, and the disconnected state of the power supply PN can be displayed.
This circuit is unique in the arrangement of contacts 2b, so that even when the two sets of switches are open, opening of 1a and 2a causes both 8 and 9 to become inoperable, resulting in an incorrect display due to the operation of the auxiliary relay 10. is prevented. In addition, the series circuit of contacts 9a and 8a is as follows:
This is not a measure against power PN disconnection, but also indicates malfunctions of the auxiliary relays 8 and 9. The auxiliary relay malfunctions simultaneously at 8 and 9, and the power supply
This is displayed only in response to PN disconnection, and the power supply PA,
NA breaks are not displayed. This power outage can be countered by the voltage drop mentioned above.

FIG. 4 shows a second embodiment of the present invention, and the contact 1
a, 1b, 2a, and 2b are arranged as shown.
The auxiliary relays 11 and 12 do not have a mechanical holding force like the above-mentioned keep relays, and operate only when receiving excitation input, and these normally open contacts 11a,
12a is closed and the normally closed contacts 11b and 12b are opened. In the system shown in FIG. 4, the operation of auxiliary relay 11 represents the opening of switch LSA, and the operation of auxiliary relay 12 represents the opening of switch LSB. As shown in the figure, the auxiliary relay 11 is energized when the contact 1b is closed or when both 1a and 2a are closed. In other words, it is determined that the switch LSA is open when the switch LSA is open, or when the switches LSA and LSB are both closed. Auxiliary relay 12 operates when contacts 1a and 2b are closed. This means that switch LSA is closed and switch
This means that it is determined that the switch LSB is open when the LSB is open. PA, NA is P,
It is a separate power supply from N, and the auxiliary relay 13 has contact 11.
Loss of power supplies P and N is detected by a combination of a, 11b, 12a, and 12b.

Figure 5a shows the state of each part when both switches LSA and LSB are open, and contacts 1a,
2a is open and contacts 1b and 2b are closed. At this time, it flows through the route P-1b-11-N,
The auxiliary relay 11 becomes operational and displays the opening of the switch LSA as previously promised. Auxiliary relay 12 has no circuit formed and is inoperative.
Due to the action of 11 and the non-action of 12, 11a, 12
b is closed and 11b and 12a are open, so the auxiliary relay 12 is inactive and does not indicate an abnormality in the power supply. When the power supplies P and N are disconnected in this state, the auxiliary relay 11 is demagnetized, 11a is opened, and 8b is closed, so that the auxiliary relay 13 indicates that the power supplies P and N are disconnected. Note that when the power is cut off, the auxiliary relay 11 returns, and the open detection output of the switch LSA is lost.

Figure 5b shows a case where the switch LSA is closed and LSB is open, and the contacts 1a and 2b are closed and the contacts 1b and 2a are closed.
is opened, the auxiliary relay 12 is energized by the circuit of P-1a-2b-12-N, and the opening of the switch LSB is indicated. Auxiliary relay 11 has no circuit formed and is inoperative. As can be understood from the above, the auxiliary relay 13 is similar to the auxiliary relays 11 and 1.
2 are energized only when both are energized or both are demagnetized, so when only the auxiliary relay 12 is energized as in this case, no output is produced. When the power supply P-N is disconnected, the auxiliary relay 12, which does not have a mechanical holding function, returns to its original state, and the PA-11b-
Auxiliary relay 13 by circuit 12b-13-NA
is excited and indicates an abnormality in the power supply P-N.

FIG. 5c shows a case where the switch LSA is open and LSB is closed, and the contacts 1b and 2a are closed and the contacts 1a and 2b are open. Although the auxiliary relay 11 is excited by the circuit P-1b-11-N, an excitation circuit for the auxiliary relay 12 is not formed. 11 outputs the closing of the switch LSA, and since the auxiliary relay 12 is not operating at this time, the auxiliary relay 13 is inoperative. If the power supply PN is cut off in this state, a state similar to that shown in FIG. 5b will occur, and this will be displayed by the auxiliary relay 13.

Finally, the case where both switches LSA and LSB are closed will be explained using FIG. 5d. Since contacts 1a and 2a close and contacts 2b and 1b open, only the P-1a-2a-11-N circuit is formed, and only the auxiliary relay 11 operates, opening the switch LSA as promised. is displayed. In this case, as in the previous case, the auxiliary relay 13 is not energized,
When the power supply PN is turned off, both auxiliary relays 11 and 12 are restored and this is displayed.

As described above, in all cases, the correct open/close state of the switch can be displayed, and the disconnected state of the power supply PN can be displayed.
This circuit is characterized by the arrangement of contacts 2a, so that even when the two sets of switches are closed, when 1b and 2b open, both 11 and 12 become inoperable, resulting in an error caused by the operation of the auxiliary relay 13. Display is prevented. Incidentally, the series circuit of contacts 11a and 12a is not a measure against power supply PN disconnection, but is also designed to indicate malfunction of auxiliary relays 11 and 12. The auxiliary relay only responds to the simultaneous malfunction of 11 and 12 and the disconnection of the power supply PN, and does not display the disconnection of the power supply PN and NA. This power outage can be countered by the voltage drop mentioned above.

[Brief explanation of the drawing]

FIG. 1 is a conventional circuit diagram, FIGS. 2 and 4 are circuit diagrams of the present invention, and FIGS. 3 and 5 are explanatory diagrams of the operation of each device. LSA, LSB... Busbar switch, 11... Keep relay, 8, 9, 10, 11... Auxiliary relay.

Claims (1)

[Claims] 1. In a busbar switch state detection device in which a power transmission line is connected to two sets of busbars via a first switch and a second switch, the device is linked to the open/closed state of the first switch. a first series circuit of a first contact that operates and a second contact that is interlocked with the open/close state of the second switch; a third series circuit that has an open/close state opposite to that of the first series circuit and the first contact; a first relay coil that is excited by a contact and changes the open/close state of its output contact only in the energized state; a fourth contact that has an open/close state opposite to that of the second contact; 2
a series circuit of the switch, a second relay coil that is excited by the second series circuit and changes the opening/closing state of its output contacts only in the excited state, and A detection means for detecting a selection condition, which is driven by a power source different from that of the first and second relay coils, and detects an abnormality in the relay coil power source when both of these two sets of relay coils are in a non-excited state. A bus switch status detection device comprising an abnormality detection means.