JP2001338555A - Control circuit for circuit breaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a circuit breaker wherein the soundness of the disconnector control circuit is checked while the breaker is energized. SOLUTION: The control circuit in the circuit breaker is provided with a mode switching relay 14. Soundness of protective relays 31-33 and the like which are external control circuits for controlling the circuit breaker are confirmed without actually operating the circuit breaker while the lines are energized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit breaker used for opening and closing a power system, and more particularly to a device capable of automatically diagnosing a control circuit of the circuit breaker.

[0002]

2. Description of the Related Art FIG. 10 is a basic circuit diagram showing a control circuit of a conventional circuit breaker. FIG. 10 shows a state where the circuit breaker is in an "open circuit" state and a closing spring is released. In the figure, 41 is a closing command switch, 42 is a trip command switch, 43 is a motor for closing spring charging, 44 is a closing coil, 45 is a voltage releasing coil, 46 is a limit switch (spring storing detection contact), 47 is a limit switch (for starting / stopping the motor 43), 48a and 48b are circuit breaker auxiliary contacts, 49 is an auxiliary relay for the motor, 50 is an auxiliary relay for preventing pumping, and R1, R2, R3 and R4 are resistors, respectively. .

Next, the operation will be described. In the case of the closing operation, first, by connecting the power supply, the coil of the auxiliary relay 49 is excited via the limit switch 47, the contact of the auxiliary relay 49 is closed, and the limit switch 4 is closed.
7, and the electric motor 43 is started via the contact of the auxiliary relay 49, and starts accumulating the closing spring. When the closing spring is completely charged, the limit switch 47 is opened and the electric motor 43 stops. At the same time, the limit switch 46 is closed, and a closed circuit control circuit is formed.

In this state, when the closing command switch 41 is closed, the closing coil 44 is excited to release the closing latch of the operation mechanism, and the energy of the closed spring causes the circuit breaker to close (close). Input). At this time, the limit switch 47 is closed and the limit switch 46 is opened by the release of the closing spring. Limit switch 47
Is closed, the electric motor 43 is started, and the closing spring is charged to prepare for the next closing operation.

When the circuit breaker is closed (closed), the circuit breaker auxiliary contact 48b is opened, the excitation of the closing coil 44 is cut off, and the auxiliary contact 48a is closed, forming a trip circuit for the voltage trip coil 45. At the same time, the pumping prevention auxiliary relay 50 is excited.

Next, a trip operation will be described. When a detection circuit (not shown) detects an abnormality or wants to manually shut off the circuit, by closing the trip command switch 42, the voltage trip coil 45 is excited, and the trip latch of the operating mechanism is activated. The engagement is released and the circuit breaker is opened.

[0007]

Since the conventional circuit breaker control circuit is constructed as described above, when a closing command switch and a trip command switch are input, the circuit breaker actually operates. However, there is a problem in that the power receiving and distribution equipment cannot be operated to check the soundness of the circuit breaker control circuit while the power receiving and distribution equipment is actually operating.

The present invention has been made to solve the above problems, and has as its object to provide an apparatus capable of checking the soundness of a circuit breaker control circuit during operation.

[0009]

According to a first aspect of the present invention, there is provided a control circuit for a circuit breaker, comprising: a closing command switch; a closing coil excited by a closing operation of the closing command switch;
It has a trip command switch and a voltage trip coil which is excited by the on-operation of the trip command switch. A mechanism in which the trip coil does not operate is provided.

A control circuit for a circuit breaker according to a second aspect of the present invention includes a mode switching relay for switching to an inspection mode, a closing command answer relay, a trip command answer relay, a closing command answer relay and a trip command. And a monitoring device for monitoring with a signal sent from the answer relay.

In the control circuit for a circuit breaker according to a third aspect of the present invention, the inspection target is an interlock circuit and a protection relay.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a control circuit of a circuit breaker having a mode switching relay for switching a mode of a closing circuit and a trip circuit according to Embodiment 1 of the present invention.
2 is a trip command switch, 3 is a mode switch, 4
Is a motor for accumulating the closing spring, 5 is a closing coil, 6 is a voltage trip coil, 7 is a limit switch (spring storage detecting contact), 8 is a limit switch (for starting / stopping the motor 4), 9a and 9b. Is a circuit breaker auxiliary contact, 10 is an auxiliary relay for the motor 4, 11 is an auxiliary relay for preventing pumping,
R1, R2, R3, and R4 are resistors, respectively, and 12 is a closing command answer relay, which includes a closing command coil 12a and an answer back contact 12b. Reference numeral 13 denotes a trip command answer relay, which includes a trip command coil 13a and an answer back contact 13b. Reference numeral 14 denotes a mode switching relay, and reference numerals 14a and 14b denote mode switching relay auxiliary contacts interlocked with the mode switching relay 14.

Next, FIG. 2 shows an open state (a closing spring released state).
2 is a side view showing the mechanical configuration of the circuit breaker in FIG. 1, in which 15 is a closing cam, 16 is a closing latch, 17 is a return spring, 18 is a release latch pin, 19 is a return spring,
0 is a release latch, 21 is a closing spring rod, 22 is a closing spring, 23 is an energy storage shaft, 24 is a small gear, 25 is a large gear, 2
6 is an output roller, 27 is an output lever, 28 is a main contact, 2
9 is a damper, 30 is a trip spring. FIG. 3 shows an open circuit state (closed spring accumulating state), and FIG.
FIG. 6 is a side view of the circuit breaker in a closed state (closed spring release state), and FIG. 6 is a closed state (closed spring stored state).

Next, the operation will be described. When the soundness of the circuit breaker control circuit is not checked, that is, in a normal operation state, the mode switch 3 is open. At this time, the mode switching relay auxiliary contact 14a is open, and the mode switching relay auxiliary contact 14b is closed. In this state, as in the case of the conventional control circuit, in the case of the closing operation, first, by connecting the power supply, the coil of the auxiliary relay 10 is excited via the limit switch 8, and the contact of the auxiliary relay 10 is closed. The electric motor 4 is started via the contacts of the limit switch 8 and the auxiliary relay 10 to start accumulating the closing spring 22. As shown in FIG. 3, when the closing spring 22 is fully charged, the limit switch 8 is opened and the electric motor 4 stops. At the same time limit switch 7
Is closed, and a closed circuit control circuit is formed.

In this state, when the closing command switch 1 is closed, the closing coil 5 is excited via the closing command coil 12a, the closing latch 16 of the operating mechanism is released, and the charged closing is performed. With the energy of the spring 22, the circuit breaker is closed (closed) as shown in FIG. At this time, the limit switch 8 is closed by the release of the closing spring 22,
The limit switch 7 opens.

At the same time, the input command answer relay 1
In step 2, the ON command coil 12a is excited to output the answerback contact 12b of the ON command switch. When the limit switch 8 is closed, the electric motor 4 is activated to accumulate the closing spring 22 and prepare for the next closing operation as shown in FIG. When the circuit breaker is closed (closed), the circuit breaker auxiliary contact 9b is opened, the excitation of the closing coil 5 is cut off, and the auxiliary contact 9a is closed to form a trip circuit for the voltage trip coil 6, The auxiliary relay 11 for pumping prevention is excited.

Next, the trip operation will be described. By closing the trip command switch 2, the voltage trip coil 6 is excited via the trip command coil 13a,
The release latch 20 of the operation mechanism is disengaged, and the circuit breaker is opened. At the same time, the answer back contact 13b of the trip command switch is output.

Next, the operation of the power receiving and distribution equipment which can check the soundness of the circuit breaker control circuit during operation using the circuit breaker having the control circuit according to the present invention will be described.
FIG. 7 is a circuit diagram showing a control circuit. The internal configuration of the circuit breaker is a simplified version of FIG. In the figure, 1 is a closing command switch, 2 is a trip command switch, 31 is an instantaneous overcurrent relay output, 32 is an overcurrent relay output, 33 is a ground fault direction relay output, 3 is a mode changeover switch,
DA1 / DA2 is a diode array, 4 is a motor, 5 is a closing coil, 6 is a voltage trip coil, 9 is a circuit breaker auxiliary contact, 12 is a closing command answer relay, and includes a closing command coil 12a and an answer back contact 12b. .

Reference numeral 13 denotes a trip command answer relay.
It comprises a trip command coil 13a and an answer back contact 13b. 14 is a mode switching relay, 14a, 14b
Is a mode switching relay auxiliary contact that is linked to the mode switching relay 14. Further, 34 is an interlock circuit, 35
Is a monitoring device for monitoring the whole.

Next, the operation will be described. The operation inside the circuit breaker is as described above. In FIG. 7, when the mode switch 3 is closed by the monitoring device 35 when the interlock circuit 34 and the like are normal, the monitoring position is entered, and even when the closing command switch 1 is closed, the mode switching relay 14 is excited. Therefore, the mode switching relay auxiliary contact 14a is closed and the mode switching relay 14b is opened, so that the closing coil 5 is not excited.

That is, there is no change in the operation of the circuit breaker, and the circuit breaker is open. It can be confirmed by monitoring the contact operation of the closing command answer relay 12 whether the closing command of the circuit breaker is activated or not according to the interlock condition. That is, whether or not the interlock circuit 34 and the like are normal can be checked by sending a signal to the monitoring device 35 from the closing command coil 12a via the answerback contact 12b.

When the mode changeover switch 3 is closed,
Even if the protection relays 31 to 33 operate, the mode switching relay auxiliary contact 14a is closed and the mode switching relay auxiliary contact 14
Since b is open, the voltage trip coil 6 is not excited, and there is no problem even if the protection relays 31 to 33 are forcibly operated. That is, a signal is sent from the trip command coil 13a to the monitoring device 35 via the answerback contact 13b, so that it is possible to monitor whether the protection relays 31 to 33 are normal.

The same applies to the operation of the trip command switch 2. Thus, the protection relays 31 to
33 or the soundness of the operation of the trip command switch 2 can be confirmed by monitoring the contact operation of the trip command answer relay 13. FIG. 8 is a circuit diagram showing a case where only the closing coil 5 and the voltage tripping coil 6 are short-circuited, and FIG. 9 is a flowchart summarizing the above test operation.

As described above, even when the power receiving and distributing equipment is on a live line, the soundness of the circuit breaker control circuit and the operation test of the protection relays 31 to 33 can be performed. As a result, in an environment where the importance of power supply is high as in today, it is easy to construct a system that can more reliably operate power receiving and distribution equipment that does not easily take power outages for periodic inspection.

[0025]

According to the control circuit for a circuit breaker according to the first aspect of the present invention, a closing command switch, a closing coil excited by the ON operation of the closing command switch, a trip command switch, and a pull-off command switch. A voltage trip coil that is excited by the ON operation of the disconnect command switch,
In the inspection mode, a mechanism is provided to prevent the closing coil and voltage trip coil from operating even when a control signal is input. be able to.

According to the circuit breaker control circuit of the present invention, a mode switching relay for switching to an inspection mode, a closing command answer relay, a trip command answer relay, a closing command answer relay and a pulling command answer relay are provided. Since the monitoring device is provided for monitoring with a signal sent from the disconnection command answer relay, the soundness of the circuit can be checked during operation.

According to the control circuit for a circuit breaker according to the third aspect of the present invention, since the objects to be inspected are the interlock circuit and the protection relay, the operation test of the protection relay and the like can be performed even during a live line. Can be.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a control circuit of a circuit breaker according to Embodiment 1 of the present invention.

FIG. 2 is a side view showing the circuit breaker according to Embodiment 1 of the present invention.

FIG. 3 is a side view showing the circuit breaker according to Embodiment 1 of the present invention.

FIG. 4 is a side view showing the circuit breaker according to Embodiment 1 of the present invention.

FIG. 5 is a side view showing the circuit breaker according to Embodiment 1 of the present invention.

FIG. 6 is a side view showing the circuit breaker according to Embodiment 1 of the present invention.

FIG. 7 is a circuit diagram showing a control circuit of the circuit breaker according to Embodiment 1 of the present invention.

FIG. 8 is a circuit diagram showing a control circuit of the circuit breaker according to Embodiment 1 of the present invention.

FIG. 9 is a flowchart showing a test operation.

FIG. 10 is a circuit diagram showing a conventional circuit breaker control circuit.

[Explanation of symbols]

1 closing command switch, 2 trip command switch, 5
Closing coil, 6 voltage trip coil, 12 closing command answer relay, 13 trip command answer relay, 14
Mode switching relay, 34 interlock circuit, 35
Monitoring device.

Claims (3)

[Claims] A switching command switch, a closing coil which is excited by an ON operation of the ON command switch, a trip command switch, and a voltage trip coil which is excited by an ON operation of the trip command switch. A control circuit for a circuit breaker, characterized in that a control circuit for the circuit breaker is provided with a mechanism that does not operate the closing coil and the voltage tripping coil even when a control signal is input in the under-inspection mode. 2. A mode switching relay for switching to an inspection mode, a closing command answer relay, a trip command answer relay, and a monitoring device for monitoring by signals sent from the closing command answer relay and the trip command answer relay. The control circuit for a circuit breaker according to claim 1, further comprising: 3. The control circuit for a circuit breaker according to claim 1, wherein the inspection target is an interlock circuit and a protection relay.