JPH07177619A - State detecting circuit for circuit breaker - Google Patents

Abstract

PURPOSE:To detect abnormality of circuit breaker easily by connecting relays between the control power supply for a circuit breaker and a closing coil and between the control power supply and a trip coil. CONSTITUTION:A relay 12 connected between the control power supply for a circuit breaker 1 and a closing coil 4 is actuated by a current flowing from the control power supply to a relay 13 and the closing coil 4 when the circuit breaker 1 is opened. Upon closure of the circuit breaker 1, the closing coil 4 and the power supply are open-circuited by an auxiliary contact 8-1 of the circuit breaker 1 to interrupt the current supply and the relay 12 is reset. A relay 13 connected between the control power supply for the circuit breaker 1 and a trip coil 5 is actuated by a current flowing from the control power supply to the relay 13 and the trip coil 5 when the circuit breaker 1 is closed. When the circuit breaker 1 is opened, the trip coil 5 and the power supply are open-circuited by an auxiliary contact 8-2 of the circuit breaker 1 and the relay 13 is reset. This constitution facilitates detection of abnormality in the circuit breaker 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker state detection circuit.

[0002]

2. Description of the Related Art FIG. 3 is a diagram showing a conventional circuit breaker state detection circuit, and a conventional circuit breaker state detection circuit will be described with reference to FIG. In FIG. 3, the circuit breaker 1 is a switchboard 2
The control power supply of the circuit breaker 1 is applied to the closing coil 4 and the trip coil 5 of the circuit breaker 1 via the fuse 3. The plug 6 and the closing operation switch 7 are connected to the positive electrode side of the closing coil 4, and the auxiliary contact 8-1 of the breaker 1 and the plug 6 are connected in series on the negative electrode side.

The plug 6 is connected to the main body of the circuit breaker 1 in a normal use position, and is disconnected only when the main body of the circuit breaker 1 is pulled out from the switchboard 2 for maintenance and inspection work. The auxiliary contact 8-1 is a normally closed contact which is closed when the circuit breaker 1 is in an open state. When the circuit breaker 1 is closed, the closing operation switch 7 is closed to close the auxiliary contact.
A current flows through the closing coil 4 via 8-1, and the breaker 1 is closed.

The positive side of the trip coil 5 of the circuit breaker 1 is connected to the plug 6 and the disconnection operation switch 9, and the negative side is connected to the auxiliary contact 8-2 of the circuit breaker 1 and the plug 6 in series. The auxiliary contact 8-2 is a normally open contact that opens when the circuit breaker 1 is open and closes when the circuit breaker 1 is closed.

Since the auxiliary contact 8-2 is closed when the circuit breaker 1 is turned on and trips, a current is supplied to the trip coil 5 through the auxiliary contact 8-2 by closing the off operation switch 9. The circuit breaker 1 opens as it flows. When the circuit breaker 1 is opened, the auxiliary contact 8-1 is closed and the next contact can be made. At the same time, the auxiliary contact 8-2 is opened and the trip coil 5 is opened.
No current flows through it.

The auxiliary contacts 8-3 and 8-4 of the circuit breaker 1 are used to detect the open / closed state of the circuit breaker 1, and these contacts are installed separately from the switchboard 2 via the plug 6. The control panel 10 is connected by a cable 11 to an auxiliary relay 12 in the control panel 10.

When the circuit breaker 1 is open, the auxiliary contact 8-
Since 3 is open and the auxiliary contact 8-4 is closed, connect the auxiliary contact 8-3 to the operating coil 12-1 of the auxiliary relay 12 and connect the auxiliary contact 8-3 to the return coil 12-2 of the auxiliary relay 12. -Four
The open / closed state of the circuit breaker 1 is detected by the normally open contact 12-3 and the normally closed contact 12-4 of the auxiliary relay 12 by connecting.

That is, the auxiliary contacts 8-3, 8-of the circuit breaker 1
By amplifying the contact point of 4 with the auxiliary relay 12, the open / closed state of the breaker 1 is detected and used in the control circuit 14. Undervoltage detector between positive and negative control power supply of circuit breaker 1.
13 is provided to monitor loss of control power supply and disconnection of fuse 3, and when control power is lost, contact point of the above-mentioned undervoltage detector 13
13-1 is closed, the contact is connected to the control panel 10 by the cable 18, and is input to the circuit breaker abnormality alarm circuit 15.

Further, a limit switch 16 which is closed when the circuit breaker 1 is pulled out is input to the circuit breaker abnormality alarm circuit 15 by connecting from the switchboard 2 to the control panel 10 with the circuit breaker 1 in the normal position. It detects that it is not in.

[0010]

The above-mentioned conventional device is connected to the control panel 10 by the cable 11 in order to detect the open / close state of the circuit breaker 1, so that one core wire of the cable 11 is disconnected, Or in case of disconnection, or auxiliary contact
If there is a contact failure of the plug 6 connected in series with 8-3 and 8-4, these abnormalities cannot be detected.

Similarly, even if the cables 18 and 17 for disconnecting the control power source of the circuit breaker 1 and detecting the circuit breaker pull-out position are broken, there is a drawback that the abnormality cannot be detected as in the above case. Further, conventionally, an undervoltage detector 13 is required for monitoring the power source of the control power source of each circuit breaker, and a limit switch 16 is also prepared and a cable for connecting the same is required.

On the other hand, in a large-scale plant such as a power plant, the number of circuit breakers used is very large, and therefore the number of cables connecting the switchboard 2 and the control panel 10 is also very large. The possibility of occurrence is great,
Further, since the probability of malfunction of the undervoltage detector 13 and the limit switch 16 also increases with the number of circuit breakers,
There is a strong demand for eliminating and simplifying these circuits to improve reliability.

The present invention has been made in view of the above circumstances, and makes it possible to easily detect an abnormality in the cable connection between the switchboard 2 and the control panel 10 and to easily detect an abnormal state of the breaker 1. An object of the present invention is to provide a highly reliable circuit breaker state detection circuit.

[0014]

In a circuit breaker state detection circuit according to [Claim 1] of the present invention, in a circuit breaker having a closing coil and a trip coil, a control power source of the circuit breaker and closing of the circuit breaker are provided. The circuit breaker includes a first relay connected across the closing operation switch between the coils, and a second relay connected across the disconnection operation switch between the control power supply of the circuit breaker and the trip coil of the circuit breaker. Is open, the first relay is in the operating state and the second relay is in the restoring state, and when the circuit breaker is closed, the first relay is in the restoring state and the second relay is operating. A configuration in which the contacts are connected to the control circuit via the individual contacts of the first and second relays, and the contacts of the first and second relays are connected in series to the circuit breaker circuit. It was.

In the circuit breaker state detection circuit according to [Claim 2] of the present invention, in [Claim 1], the relay is housed in a control panel different from the switchboard in which the circuit breaker is housed.
A cable is connected between them.

A circuit breaker state detection circuit according to a third aspect of the present invention is a circuit breaker having a closing coil and a trip coil. In the circuit breaker, a closing operation switch is provided between the control power source of the circuit breaker and the closing coil of the circuit breaker. A first relay connected across the circuit breaker and a second relay connected across the cut-off operation switch between the control power supply of the circuit breaker and the trip coil of the circuit breaker, and when the circuit breaker is open, The first relay is in the operating state and the second relay is in the returning state, and when the circuit breaker is closed, the first relay is in the returning state and the second relay is in the operating state. A first detection circuit that is connected to a control circuit via individual contacts of the first and second relays and that detects that both the first and second relays are returning; Each of 2 Appliances were configured to connect to the circuit breaker abnormality alarm circuit by connecting the second detection circuit for detecting that it is working together in parallel respectively.

In the circuit breaker state detection circuit according to [Claim 4] of the present invention, in [Claim 1] or [Claim 3], a photocoupler is installed in place of each relay.

[0018]

In the circuit breaker state detection circuit according to claim 1, the relay connected between the control power source of the circuit breaker and the closing coil controls the relay and the closing coil when the circuit breaker is open. It operates when a current flows from the power supply. However, in this case, the impedance of the relay is sufficiently higher than the impedances of the closing coil and the trip coil of the circuit breaker, so that the circuit breaker does not operate by the above current.

Further, when the breaker of the relay is closed, the auxiliary coil contact inside the breaker opens the space between the closing coil and the power source, so that the current does not flow and the relay is restored. On the other hand, the relay connected between the control power supply of the circuit breaker and the trip coil operates when a current flows from the control power supply to the relay and the trip coil when the circuit breaker is closed.

When the breaker is opened, the trip coil and the power source are opened by the auxiliary contact of the breaker as in the case of the closing coil side, so that the relay is restored. Therefore, the open / closed state of the breaker can be detected depending on which of the two relays is operating. Therefore, both relays cannot operate together, and by connecting these contacts in series, an abnormal alarm of the breaker can be issued.

Since the circuit breaker state detection circuit according to [Claim 2] of the present invention is connected to the switchboard in which the two relays are housed in the control panel and the circuit breaker is housed by a cable, When the cable is broken, the control power is lost, the main body of the breaker is pulled out from the switchboard, or when the closing coil or the trip coil is broken, both of the two relays can be detected in the reset state.

The circuit breaker state detection circuit according to [Claim 3] of the present invention, in addition to the operation of [Claim 1], the two relays have either one of the circuit breaker and the cable connection being normal. Only the relay of must be working,
When both are in the recovery state or both are in the operating state, it can be detected as an abnormality, and an abnormality in the breaker and an abnormality in the cable connection can be easily detected.

Since the circuit breaker state detection circuit according to [Claim 4] of the present invention operates the photocoupler instead of the relay to perform the same operation as opening and closing the contact, it does not require a physical contact and has a structure. Is easy and does not malfunction.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram showing an embodiment for explaining a circuit breaker state detection circuit according to [Claim 1] of the present invention, which will be described below with reference to FIG. In FIG. 1, the circuit breaker 1 is housed in a switchboard 2, and the control power source side of the circuit breaker 1 is applied to a closing coil 4 and a trip coil 5 of the circuit breaker 1 via a fuse 3.

The positive side of the closing coil 4 is connected to the positive electrode of the power source in series with the plug 6 and the closing operation switch 7 of the breaker 1, and the negative side of the closing coil 4 is the auxiliary contact 8-1 of the breaker 1.
And the plug 6 are connected in series to the negative electrode of the power supply. The plug 6 is disconnected only when the main body of the circuit breaker 1 is pulled out from the switchboard 2, and the plug 6 is connected when the circuit breaker 1 is normally used.

The positive pole side of the trip coil of the circuit breaker 1 is connected to the positive pole of the power source in series with the plug 6 and the disconnection operation switch 9, and the negative pole side of the trip coil 5 is the auxiliary contact 8-2 and the plug 6 of the circuit breaker 1. Are connected in series to the negative electrode of the power supply.
On the other hand, in the control panel 10 installed separately from the switchboard 2,
The cable 11 connects the positive electrode of the control power source via the fuse 3 in the switchboard 2.

In the control panel 10, a positive electrode is connected to the control power source, and a negative electrode side is connected via a cable 11 to a connection point between the closing operation switch 7 and the positive side plug 6 of the closing coil 4 (hereinafter referred to as a relay 12). TPR) and a relay 13 (hereinafter, referred to as CPR) in which a positive electrode is connected to the control power source and a negative electrode side is connected to a connection point between a cut operation switch 9 and a positive electrode side plug 6 of a trip coil 5 via a cable 11. Is stored.

The operating contact 12-1 of the TPR 12 and the operating contact 13-1 of the CPR 13 are connected to the control circuit 14 as a signal of the open / close state of the breaker. On the other hand, a contact 12-2 which is closed when the TPR 12 is restored and a contact 13-2 which is closed when the CPR 13 is restored are connected in series and input to an abnormality alarm circuit 15 of the circuit breaker. 2]).

Next, the operation will be described. In FIG. 1, since the auxiliary contact 8-1 inside the circuit breaker 1 is closed when the circuit breaker 1 is open, the TPR 12, the plug 6, the closing coil 4, the auxiliary contact 8-
1, current flows to the negative electrode of the control power supply through the plug 6,
The open state of the circuit breaker 1 can be detected by operating the TPR 12 and closing the contact 12-1 of the TPR 12.

Here, the impedance of the TPR 12 is sufficiently larger than the impedance of the closing coil 4, so that the breaker 1 is not closed. The circuit breaker 1 is closed by closing the closing operation switch 7. When the circuit breaker 1 is closed, the auxiliary contact 8-2 of the circuit breaker 1 is closed and the auxiliary contact 8-1 is opened.

Therefore, the above-mentioned TPR12 is restored, and the auxiliary contact is made.
When 8-2 is closed, current flows from the control power supply to CPR13 and trip coil 5, and CPR13 operates. Also in this case, the impedance of CPR13 is trip coil 5
The circuit breaker 1 will not trip by using a sufficiently large impedance as compared with the impedance of.

The closed state of the circuit breaker 1 can be detected by closing the contact 13-1 by the operation of the CPR 13. Therefore, the open / closed state of the circuit breaker 1 can be detected by the above TPR12 or CP.
It can be detected by the operation of R13, and only one of them is always operating.

Here, when the fuse 3 is broken or the control power source is lost, both the TPR12 and CPR13 are restored and both contacts 12-2 and 13-2 are closed.
15 operates and can detect abnormalities. When the cable 11 is broken, the closing coil 4 of the breaker 1 is broken, and the trip coil 5 is broken, the breaker 1 main body is pulled out from the switchboard 2 and the plug 6 is open. Therefore, the above abnormality can be detected.

According to the above-described embodiment, not only the open / closed state of the circuit breaker 1 is detected, but also the control power source abnormality, the cable 11 disconnection, the closing coil 4 disconnection, the trip coil 5 disconnection, and the breaker 1 extraction position. In addition to easily detecting the state, the following effects can be obtained.

(1) By using TPR12 and CPR13, the undervoltage detector for detecting the control power supply disconnection inside the switchboard 2 and the circuit breaker 1 and the limit switch for detecting the withdrawal position of the circuit breaker 1 are not required, and the switchboard 1 2 The internal circuit is simplified and reliability is improved.

(2) Since the cable between the switchboard 2 and the control panel 10 only needs one 3-core cable for detecting the state of the circuit breaker, a cable disconnection accident occurs due to the reduction in the number of cables and the decrease in the number of cables. The possibility of can be greatly reduced.

(3) Since the contacts of TPR12 and CPR13 can be used directly, the auxiliary contact of the circuit breaker 1 is interlocked with the operation of the circuit breaker 1 as compared with the case where the auxiliary contact of the circuit breaker 1 is used through an auxiliary relay. It can be treated as a contact equivalent to.
In other words, since the auxiliary relay is not used, a breaker switching signal without time delay can be obtained.

FIG. 2 is a block diagram of an embodiment for explaining a circuit breaker state detection circuit according to [Claim 2] of the present invention.
2, the same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. The difference from FIG. 1 is only the circuit breaker abnormality detection circuit, and the rest is the same as FIG.

First, in FIG. 2, a contact point 12-2 that closes when the TPR 12 returns and a contact point that closes when the CPR 13 returns.
A contact 12-3 that connects 13-2 in series and closes when the TPR12 operates and a contact 13-3 that closes when the CPR13 operates
Is connected in series and is connected in parallel with the series circuit of the contact 12-2 and the contact 13-2 (this is [claim 3]).

Next, the operation will be described. The circuit breaker 1
In case of disconnection of control power source or disconnection of cable 11, TPR12 and CPR13 both recover as described above, so contact 12
-2 and contact 13-2 are both closed and input to the alarm circuit, and the abnormality can be detected.

When the negative side of the TPR12 and the negative side of the CPR13 are short-circuited, for example, when a short circuit occurs at the short-circuit point a of the cable 11, the TPR12 and the CPR13 are connected in parallel. Therefore, depending on the open / closed state of the circuit breaker 1, current flows through both the TPR12 and CPR13 via the closing coil 4 or the trip coil 5, and both TPR12 and CPR13 operate.

In the above description, the coil resistance of the relay is sufficiently higher than the coil resistance of the circuit breaker. However, a relay having a small coil resistance and a resistance having a resistance value sufficiently higher than the coil resistance of the circuit breaker are used in series. However, it goes without saying that exactly the same effect can be exhibited. Further, when the present invention is applied, selection of the relay does not hinder.
In each of the above embodiments, the relay (TPR) 12 and the relay (CP
R) 13 used to close contacts 12-
The circuit breaker circuit was activated by connecting 3 and 13-3 in series. However, the relay is not limited to this type of relay, and a photo coupler may be used (this is [claim 4]). In other words, the photo coupler may be operated to close the contacts 12-3 and 13-3. In this case, no physical contact is required, and the configuration becomes even simpler. Therefore, according to the present embodiment, the contact 12-3 and the contact 13
By connecting -3 in series, not only the short circuit of the cable 11 but also the short circuit between the closing circuit and the trip circuit of the circuit breaker 1 can be detected.

[0043]

As described above, according to the present invention, a relay is connected between the control power supply and the closing coil of the circuit breaker and between the control power supply and the trip coil, and the relay needs to detect the state of the circuit breaker. Since it is configured to be housed in the control panel, it is possible to easily detect an abnormality in the connection between the switchboard housing the circuit breaker and the control panel and an abnormality in the circuit breaker.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a circuit breaker state detection circuit according to the present invention.

FIG. 2 is a diagram showing an embodiment of a circuit breaker abnormality detection circuit different from that in FIG. 1;

FIG. 3 is a diagram showing a conventional circuit breaker state detection circuit.

[Explanation of symbols]

 1 Breaker 2 Switchboard 3 Fuse 4 Closing coil 5 Trip coil 6 Plug 7 Closing operation switch 8-1 to 8-4 Breaker auxiliary contact 9 Breaking operation switch 10 Control panel 11, 17, 18 Cable 12-1, 12-3 Relay (TPR) operation contact 12-2 Relay (TPR) return contact 13 Relay 13-1, 13-3 Relay (CPR) operation contact 13-2 Relay (CPR) return contact 14 Control circuit 15 Circuit breaker fault alarm circuit 16 Limit switch

Claims (4)

[Claims] 1. A circuit breaker having a closing coil and a trip coil, a first relay connected across a closing operation switch between a control power source of the circuit breaker and a closing coil of the circuit breaker, and control of the circuit breaker. A second relay is provided between the power supply and the trip coil of the circuit breaker across the disconnection operation switch. When the circuit breaker is open, the first relay is in the operating state and the second relay is in the reset state. And the first relay is in the reset state and the second relay is in the operating state when the breaker is turned on, and the control circuit is connected to the control circuit through the individual contacts of the first and second relays. A circuit breaker state detection circuit, characterized in that the contacts are connected and the contacts of the first and second relays are connected in series and connected to a circuit breaker abnormality circuit. 2. The circuit breaker state detection circuit according to claim 1, wherein the relay is housed in a control panel different from a switchboard housing the circuit breaker, and a cable is connected between the relays. . 3. A circuit breaker having a closing coil and a trip coil, a first relay connected across a closing operation switch between a control power source of the circuit breaker and a closing coil of the circuit breaker, and control of the circuit breaker. A second relay is provided between the power supply and the trip coil of the circuit breaker across the disconnection operation switch. When the circuit breaker is open, the first relay is in the operating state and the second relay is in the reset state. And the first relay is in the reset state and the second relay is in the operating state when the breaker is turned on, and the control circuit is connected to the control circuit through the individual contacts of the first and second relays. A first detection circuit that is connected and that detects that both the first and second relays are returning, and a second detection circuit that detects that both the first and second relays are operating Detection circuit A circuit breaker status detection circuit characterized in that the circuit breaker abnormality alarm circuits are connected in parallel with each other. 4. The circuit breaker state detection circuit according to claim 1, wherein a photocoupler is installed in place of each of the relays.