JPH02158021A - Closing control circuit of breaker - Google Patents

Abstract

PURPOSE:To prevent the pumping of a breaker by providing a back-up protecting relay energized by the close of an auxiliary relay of the breaker only when a pumping preventing relay is not operated to prohibit the reenergization of a closing coil by the close of the B contact. CONSTITUTION:When an input command signal 4 is given to an input control circuit 1A from the outside and a current is sent to an input coil 52C, the coil 52C is energized, and a breaker conducts an closing operation. The auxiliary contact point 52a1 of a breaker is closed just before the completion of the input operation of the breaker, a pumping preventing relay 52Y is energized to close its a contact 52Y2. Hence, a holding circuit for the relay 52Y is formed, and at the same time, the b contact point 52Y1 of the relay 52Y is opened. As the self holding of the relay 52Y is never released as long as the input command signal 4 is continued, the b contact point 52Y1 remains opened, and the coil 52C is never reenergized even if the breaker is tripped after the input. The b contact of the relay 52Y is opened earlier than a contact 52Y3 is closed, and thus, a back-up protecting relay 52Z is never energized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a closing control circuit for a circuit breaker.

[Prior Art] FIG. 3 is a circuit diagram similar to a conventional circuit breaker closing control circuit disclosed in, for example, Japanese Utility Model Application No. 54-176861. However, only relevant parts are shown as a conventional example of the present invention. In the figure, when a closing command signal (4) is externally applied to the closing control circuit (1) of a circuit breaker (not shown) and current flows through the closing coil (52C),
C) is energized and the circuit breaker performs a closing operation. The auxiliary contact (52al) of the circuit breaker closes immediately before the closing operation of the circuit breaker is completed, thereby triggering the anti-pumping relay (52Y).
is excited and closes its a contact <52Y2). Pumping prevention relay (
52Y) is formed (the closing command signal (4) continues), the b contact (52Y1) of the anti-pumping relay (52Y) closes. Further, the auxiliary contact (52b) of the circuit breaker must close substantially simultaneously with the closing of the auxiliary contact (52al). The pumping prevention relay (52Y) will not release its self-holding status as long as the closing command signal (4) continues, so
The ti point (S2Y1) remains closed, and the closing coil (52C) is not re-energized even if the circuit breaker is in the closing state.

Generally, the operational responsibility of a circuit breaker is to perform an exception after an accident occurs, reclose the circuit after 0.3 seconds, and immediately trip again if the accident continues. There is. When tripping occurs again, closing command signal (4)
Even if this continues, the closing coil (S2C) is not energized because the b contact (52Y1) of the pumping prevention relay (S2Y) is in circuit, so that the circuit breaker is prevented from closing again.

[Problems to be Solved by the Invention] In the conventional circuit breaker closing control circuit as described above, prevention of pumping of the circuit breaker relies only on the pumping prevention relay (52Y).
If the circuit breaker does not operate properly due to a disconnection or the like, the circuit breaker will repeat pumping, causing a serious problem in the power system.

This invention was made to solve the above-mentioned problems, and provides a circuit breaker closing control circuit that can reliably prevent circuit breaker pumping even if the pumping prevention relay (52Y) fails. The purpose is to

[Means for Solving the Problems] A closing control circuit for a circuit breaker according to the present invention includes a closing coil of the circuit breaker to be excited in response to a closing command signal, and a closing coil of the circuit breaker that is to be excited in response to the closing command signal and a first coil of the circuit breaker. a pumping prevention relay that is energized and self-held by the closing of the auxiliary A contact, and has its own B contact connected in series with the closing coil; backup protection, which is energized and self-maintained by the closing of the second auxiliary a contact of the circuit breaker that closes with a delay and the closing of the b contact of the anti-pumping relay, and whose own b contact is connected in series with the closing coil; It is equipped with a relay for use.

[Function] The backup protection relay of the present invention is energized and self-held by closing the second auxiliary contact of the circuit breaker only when the anti-pumping relay does not operate despite receiving a closing command signal. , the re-excitation of the closing coil is prohibited by closing the b contact.

[Embodiment] FIG. 1 is a circuit diagram showing an embodiment of the present invention. In the figure, the closing control circuit (IA) of the circuit breaker (not shown) includes a closing coil (52C), a pumping prevention relay (52C), and a pumping prevention relay (52C).
Y) and a back-up protection relay (52Z) for the pumping prevention relay (52Y). Closing coil (52C)
A series body in which the auxiliary contact (52b) of the circuit breaker, the b contact (52Y1) of the pumping prevention relay (52Y), and the b contact (5221) of the backup protection relay (522) are connected in series with each other, and the pumping prevention relay (S2Y
) is connected in series with the auxiliary contact (52al) of the circuit breaker and the a contact (52Y2) of the anti-pumping relay (52Y), respectively, and the auxiliary contact (52a2) of the circuit breaker is connected to the backup protection relay (522>). Backup protection relay (52
A series body formed by connecting a parallel body with the a contact (52z2) of Z) in series via the b1M point (52Y3) of the pumping prevention relay (52Y) is connected in parallel with each other. In addition, the a contact of the pumping prevention relay (52Y) (
52Y4) and back-up protection relay (522) a contact (
5223) are connected to terminals (2) and (3), respectively, so that their signals can be sent to a central control room (not shown). The auxiliary contact (52a2) of the circuit breaker is adjusted to close a predetermined time later than the auxiliary contact (52al).

When a closing command signal (4) is applied to the closing control circuit (IA) from the outside and a current flows through the closing coil (52C), the closing coil (52C) is excited and the circuit breaker performs a closing operation. The auxiliary contact (52al> of the circuit breaker closes immediately before the closing operation of the circuit breaker is completed, thereby energizing the pumping prevention relay (52Y) and closing its a contact (52Y2). Closing of the a contact (52Y2) When a self-holding circuit is formed for the anti-pumping relay (52Y) (the closing command signal (4) continues), substantially at the same time, the b contact (
52Yl) is closed. In addition, the auxiliary contact of the circuit breaker (52
b) closes substantially simultaneously with the closing of the auxiliary contact (52al). Since the pumping prevention relay (S2Y) does not release its self-holding state as long as the closing command signal (4) continues, its b contact (52Yl) remains closed.
Even if the circuit breaker is disconnected after closing, the closing coil (52C
) is never re-energized. Auxiliary contact of circuit breaker (52
As mentioned above, the auxiliary contact (S2) closes after a predetermined time (t) than the auxiliary contact (52al).
The b contact (52Y3) of the pumping prevention relay (S2Y) closes faster than a2), so the backup protection relay (522) is not energized.

A contact (52Y4) of pumping prevention relay (52Y)
is closed by the operation of the pumping prevention relay (52Y), and the pumping prevention relay (52Y) is connected to the central control room.
) sends a signal indicating normal operation.

Here, if the coil of the pumping prevention relay (52Y) is disconnected, its b contact (52Y3) will not be closed, so the backup protection relay (522) will be closed by closing the auxiliary contact (52a2) of the circuit breaker. ) is excited.

When the back-up protection relay (522> is energized, its b contact (5221) is closed, and its a contact (52z2)
are also closed at the same time, so backup protection relays (5
2Z) is formed (the closing command signal (
4) continues). Therefore, the closing command signal (
As long as 4) continues, the b contact (52Zl) remains closed and the closing coil (52C) is not energized again. In addition, the operation of the back-up protection relay (52Z) causes its a contact (52Z3> to close, and sends a signal to the central control room notifying the operation of the back-up protection relay (522).This signal is sent to the anti-pumping relay (52Z). 52Y
) is a signal indicating non-operation due to wire breakage, etc.

In this way, the closing control circuit (IA) of this embodiment prevents pumping of the circuit breaker by operating the back-up protection relay (52Z) even when the anti-pumping relay (52Y) is not operating, and at the same time prevents pumping of the circuit breaker by operating the anti-pumping relay (52Z). <52Y
) will immediately notify the central control room that an abnormality has occurred.

Fig. 2 is a time chart showing the operation of the contacts of each relay and circuit breaker mentioned above, and a high level indicates a closed state of the contacts;
A low level represents a closed state of the contact.

In addition, in the above embodiment, the pumping prevention relay of the circuit breaker (
Relay for backup protection (52Y) for backup protection (52Y)
2), but it goes without saying that it can also be used for monitoring coil disconnections in general important circuits.

[Effects of the Invention] As described above, according to the present invention, only when the anti-pumping relay does not operate despite receiving a closing command signal, the relay is energized and self-maintained by closing the auxiliary contact of the circuit breaker. We installed a back-up protection relay that prohibits re-excitation of the closing coil by closing the b contact.
Pumping of the circuit breaker can be prevented even when the anti-pumping relay fails, and the failure of the anti-pumping relay can be notified to the central control room. Therefore, there is an effect that a more reliable circuit breaker closing control circuit can be provided.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing a circuit breaker closing control circuit according to an embodiment of the present invention, FIG. 2 is a time chart showing the operating states of each relay and auxiliary contact of the circuit breaker shown in FIG. 1, and FIG. FIG. 2 is a circuit diagram showing a conventional circuit breaker closing control circuit. In the figure, (IA) is the closing control circuit, (4) is the closing command signal, (52C) is the closing coil of the breaker, (52Y)
is the pumping prevention relay, <522) is the rear (11# protection relay), (52Y1.52Y3) is the b contact of the pumping prevention relay (52Y), (5221) is the backup protection relay (5zz) is the knob b contact, (52al , 52a2>
is the auxiliary contact of the circuit breaker. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] (1) The closing coil of the circuit breaker is to be energized upon receiving the closing command signal, and the circuit breaker is energized and self-held by the closing command signal and the closing of the first auxiliary a contact of the circuit breaker, and has its own b contact. a pumping prevention relay connected in series with the closing coil; closing a second auxiliary a contact of the circuit breaker that closes after a predetermined time delay from the closing command signal and the closing of the first auxiliary a contact; A closing control circuit for a circuit breaker, comprising a back-up protection relay that is energized and self-held by closing a b contact of a pumping prevention relay, and has its own b contact connected in series with the closing coil.