JPH0795410B2 - Breaker predictive maintenance device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a predictive maintenance device for circuit breakers.

[Conventional technology]

When a circuit breaker or a switch (which is referred to as a circuit breaker in this specification) has a failure, the effect of the failure is large, and therefore it is required to be detected in advance.

As the pre-detection, it is considered that there is a sign that the circuit breakers are abnormal.

The one conventionally considered is to capture the control signal P ₃ of the control switch for controlling the opening and closing of the circuit breakers as shown in FIG. 5 and the operation signal P ₂ of the auxiliary switch linked to the operation of the movable parts of the circuit breakers. , The closing time difference t between the two is monitored.

It should be noted that P ₁ indicates the contacting / separating state of the movable contactor of the circuit breaker with respect to the fixed contactor, and the control switch is closed to control the closing operation, whereby the auxiliary switch is closed.

[Problems to be solved by the invention]

As described above, the movable contactor and the auxiliary switch work together. However, since both of them are interlocked via the mechanical section, there is a variation in the operation timing t'of the movable contactor and the auxiliary switch due to backlash of the mechanical section, wear of the auxiliary switch, adjustment failure, etc. Even if monitored, the sign of abnormality cannot be grasped accurately.

Furthermore, as a fundamental problem, even if a symptom of abnormality can be caught, it is impossible to distinguish in which part of the circuit breaker it occurs.

In view of the above points, the present invention captures the relationship between the waveform of the control current and the operating state of the rotary operation shaft, and determines in which part of the circuit breakers the abnormal sign has occurred. The purpose of the present invention is to provide a predictive maintenance device.

[Means for solving problems]

In the present invention, the operation stroke of the movable contactor is derived by the motion of the rotary operation shaft, the waveform of the control current for operation is derived, and these are transmitted to the monitoring station by an electric signal and an optical signal.

At the monitoring station, the time between each point is recognized by observing the rising point of the current waveform, the minimum point, the operation start point of the rotary operation shaft, and the predetermined predetermined angle rotation point from these signals.
Then, these times are compared with the reference value of the anomaly sign, and if any one exceeds the reference value, an alarm is issued and the sign of the abnormality is notified.

[Action]

As described above, by adding the waveform of the control current to the operation of the movable contactor derived by the rotation of the rotary operation shaft, the time t _{1 to} t ₃ between each point can be recognized and compared with the reference value. By doing so, it is possible to reliably know which part of the circuit breaker has an abnormal sign.

〔Example〕

The present invention will be described below with reference to the embodiments illustrated in FIGS.

In FIG. 1, CB indicates a circuit breaker, and the circuit breaker CH and the operation device OP
Consists of

The shut-off portion CH includes a fixed contact 1 and a movable contact 2 that contacts and separates from the fixed contact 1, input and output terminals 3 and 4, an insulating operation rod 5 that operates the movable contact 2, an operation link 6, a rotation operation shaft 7, a link. The container 8 and the like. Reference numeral 9 is a supporting insulator.

The rotary operation shaft 7 extends through the link container 8 to the outside and is connected to the operation device OP.

In this example, the operation device OP is an air injection spring cutoff device, and is specifically configured as follows. That is, the link 11 connected to the rotary operation shaft 7 is connected to the connection operation rod 12. A blocking spring 13 is installed on the operating rod 12.

Further, an auxiliary switch 17 having a normally open contact point 17a and a normally closed contact point 17b is connected to one end of the operation rod 12 via levers 14 and 15, and a link 16.

Further, one end of a first lever 19 is connected to the other end of the connecting operation rod 12 via a pin 18.

The other end of the first lever 19 is in contact with the piston rod 20. The piston rod 20 is planted on one surface of a piston 22 arranged in the closing operation cylinder 21.

Compressed air is supplied to the piston 22 from an air tank 24 via a closing solenoid valve 23.

The closing solenoid valve 23 is operated by exciting the closing coil 25.

The closing coil 25 is a control switch GS _{1 for} closing control.
By closing, the control current flows from the control power source E and is excited.

A shunt SH ₁ is inserted in series with the control switch CS ₁ .

The middle point of the first lever 19 is the intermediate lever 26, the second lever 2
7, the third lever 28, the link 29, and the half-moon lever 30 to receive the half-moon-shaped lock pin 31.

By the rotation of the lock pin 31, the engagement relationship between the link and the lever is broken.

The trip coil 32 is a control switch CS for opening control.
By closing ₂ it is excited by the control power supply E and the lock pin 3
Rotate 1.

Control Sui Tutsi CS ₂ and shunt SH ₂ in series are inserted.

A latch 33 is arranged so as to engage with the other end of the intermediate lever 26.

The connecting operating rod 12 is provided with a stopper 34 and a damper 35.

A thin disc 51 such as an optical rotary encoder is directly connected to the rotary operation shaft 7 of the circuit breaker CB.

As shown in FIG. 2, the disc 51 is provided with a slit 52 that penetrates the front and back of the outer periphery.

A light emitter 53 and a light receiver 54 are arranged on both sides of the slit 52,
It is adapted to transmit and receive light through the slit 52.

Optical cables 55 and 56 are connected to the projector 53 and the receiver 54, and are guided to a remote electromagnetic shielded monitoring station 57.

As will be described later, the monitoring station 57 is provided with an evaluator 58 which recognizes each signal for a predetermined time, compares the recognized value with a reference value stored in advance, and issues an alarm when the set maintenance level is reached. There is.

The light source may be provided at the monitoring station 57.

Light is emitted from a light source (not shown) and returns to the evaluator 58 via the optical cable 55, the light projector 53, the light receiver 54, and the optical cable 56.

When the slit 52 of the disc 51 is on the optical axis,
Light is projected between 3 and 54.

However, when the disc 51 rotates and the slit 52 deviates from the optical axis, the light is blocked by the disc 51.

Therefore, when the rotary operation shaft 7 is rotated to turn on / off the movable contact 2, the disc 51 also rotates in conjunction with the shaft 7.

Therefore, the slit 52 moves between the light emitters / receivers 53 and 54, and the light receiver 54 obtains a signal S ₁ as a pulse train of light corresponding to the stroke of the movable contactor.

This pulse train S ₁ is observed at the monitoring station 57. The evaluator 58 takes in the signal S ₁ and determines the operating angle of the rotary operation shaft 7, that is, the various phases of the movable contact 2.

The waveform of the closing coil 25 and trip the control current flowing through the coil 32 of the circuit breaker CB is shunt derived in SH ₁ and SH _2, the electric signal S ₂ to the monitor station 57 by a cable 75, 76 and 77, 78,
It is led as S ₃ .

In addition, the voltage value of the control power source E of the circuit breaker CB is also the cables 81, 82
The electric signal S ₄ cables 81 and 82 as an electric signal S ₄ is guided to the monitor station 57, a voltage variation is monitored by.

At the monitoring station 57, these signals S _{1 to} S ₄ are introduced into the evaluator 58.

Here, returning to FIG. 1, this figure shows a cutoff state. To do this, the control switch CS ₁ should be closed.

As a result, the closing coil 25 is excited and the closing solenoid valve 23 moves to the right. Therefore, the compressed air in the air tank 24 is supplied into the cylinder 21 to move the piston 22 to the left.

Therefore, the first lever 19 rotates clockwise, and the connecting rod
Move 12 to the right.

As a result, the rotary operation shaft 7 rotates clockwise and the movable contactor 2 is inserted into the fixed contactor 1. At the same time, the breaking spring 13 is charged. Further, the other end of the first lever 19 is locked by a latch 33 to prepare for shutting off.

The spring force of the shut-off spring 13 is levers 19, 26, 27, 28 and link 2
9. It becomes a small force through the lever 30 and is received by the lock pin 31.

To shut off from this state, use the control switch.
The CS ₂ may be closed and the trip coil 32 may be excited.

As a result, the lock pin 31 rotates and the half-moon lever 30 rotates counterclockwise. Accordingly, the locked state of the link and the lever is broken, the breaking spring 13 releases the force, and the rotary operation shaft 7 is rotated in the counterclockwise direction so that the movable contactor 2 is disconnected from the fixed contactor 1.

The waveforms of the control currents flowing through the closing coil 25 and the trip coil 32 are derived via the shunts SH ₁ and SH ₂ and given to the evaluator 58 of the monitoring station 57 as signals S ₂ and S ₃ .

It is known that when the closing coil 25 and the tripping coil 32 are excited, the control current waveform has two peaks like the signals S ₂ and S ₃ in FIG.

This is for the following reason. Now, for convenience of explanation, the closing coil 25
Only the case of excitation will be described.

First, when excitation of the closing coil 25 is started at time u ₁ , the control current increases. There, Plungeer starts to move left.

The movement of the plunger causes the reactance of the circuit to rapidly increase, so that the control current is once limited, and at time u ₂ , the movement of the plunger is completed and reaches a minimum value.

When the movement of the plunger is completed, the closing solenoid valve moves to the right and the movable contactor 2, that is, the rotary operation shaft 7 starts operating at time u ₃ .

The rotating operation shaft 7 moves to a predetermined position, and at time u ₄ , the movable contactor 2 (that is, the rotating operation shaft 7) contacts the fixed contactor 1 and the circuit breaker.
CB input is complete.

Therefore, the normally closed contact 17b of the auxiliary switch 17 is opened, and the control current flowing through the closing coil 25 is reduced.

Here, the stroke curve of the movable contact 1 is shown in FIG.
It becomes like S ₀ . Also, when the movable contactor 2 is brought into contact with and separated from the fixed contactor 1, it becomes as shown by a curve S ₁ ′ in FIG.

The movable contact 2 is connected to the rotary operation shaft 7 as described above. Therefore, the movement of the movable contactor 2 can be represented by the rotation of the rotary operation shaft 7.

Now, in FIG. 3, the time between time u ₁ and u ₂ is t ₁ , and time u ₂
And u ₃ is t ₂ , the time between times u ₃ and u ₄ is t ₃ , and the rotation angle from the operation start point of the rotary operation shaft 7 to a predetermined position is l _1. , The total rotation angle to the final stroke position is l ₂ .

Then, the time t ₁ is the time until the coil is excited and the plunger completes its operation.

The time t ₂ is the time until the operation of the plunger is completed and the rotary operation shaft 7 starts to move, such as the supply of compressed air and the operation of the injection solenoid valve 23, when viewed from the injection side. Lock pin when viewed from the trip side
31 is rotated, and the engagement of the link and lever is broken.
Is the time until the rotary operation shaft 7 starts to operate. That is, it means the required operation time of the operating mechanism.

Time t _3, the movable contact 2, i.e. the rotational operation shaft 7 is operated from the start a predetermined angle (l ₁ only) is the time to move. When viewed from the closing side, if there is a decrease in air pressure due to the time required for the operation of the piston 22 and the first lever 19, it naturally changes.

Seen from the trip side, if there is a change in the spring force of the breaking spring 13, it changes. As described above, the time t ₃ means the required operation time of the drive part of the cutoff part.

The l ₁ is a predetermined rotation angle of the rotary operation shaft 7 set to determine the time t _3, and the number of pulses obtained when the slit 52 of the disc 51 turns the light on and off (n as described later) Individual).

l ₂ is the total rotation angle from the start to the end of the operation of the rotary operation shaft 7, which is also represented by the number of pulses (m as will be described later) like l ₁ .

Now, returning to FIG. 2, the evaluator 58 provided in the monitoring station 57 will be described.

The evaluator 58 is constructed, for example, as shown in FIG. In the figure, UC is an up-down counter, D is a digital memory, P is a pattern recognition circuit, H is a voltage correction circuit, and K.
Is an abnormality determination circuit, OR is an OR circuit, and Q is an abnormality alarm display circuit.

Here, the signal S ₁ indicating the movement of the rotary operation shaft 7 is taken in by the counter UC, and the counter UC gives its output to the digital memory D.

The digital memory D has a closing coil 25 and a tripping coil.
The signals S ₂ and S ₃ showing the waveforms of 32 control currents are also taken in. Therefore, the digital memory D synthesizes these signals and gives them to the pattern recognition circuit P.

This circuit P uses the signals S _{1 to} S ₃ for the time t ₁ to S ₃ seen in FIG.
The rotation angles l ₁ and l ₂ represented by t ₃ and the number of pulses are derived.

Specifically, the time relationship between the number of pulses of the signal S ₁ and the signals S ₂ and S ₃ is recognized.

Now, regarding the signal S _1, it is assumed that the position where n pulses are transmitted is set as the predetermined position N and is preset, and it is assumed that this corresponds to the position where the movable contact 2 contacts the fixed contact 1 ( This is determined by the initial adjustment.), And it has been calculated whether the number of transmitted pulses was n and how much time t ₃ was required for the transmission.

The starting point u ₃ of time t _{3 is} the starting point of the rotary operation shaft 7. The end point u ₄ of the time t ₃ is the predetermined angular rotation time of the rotary operation shaft 7, that is, the time when n pulses are recognized.

Further, assuming that the number of pulses obtained by rotating the rotary operation shaft 7 at all angles (corresponding to the full stroke movement of the movable contactor 2) is m (this is determined by the initial adjustment), it is currently transmitted. It verifies whether or not at least m pulses have been received.

Next, focusing on the signals S ₂ and S ₃ , the waveforms of the control currents flowing through the closing coil 25 and the trip coil 32 are identified by the pattern recognition circuit P, and the times t ₁ and t ₂ are related to the signal S _1. Have been identified.

The waveform of the control current is affected by the fluctuation of the control current E. Accordingly, the voltage signals S ₄ and S ₅ of the control current are given to the voltage correction circuit H, and the times t ₁ and t ₂ identified by the pattern recognition circuit P are the values t ₁ ′ in the case of the waveform at the normal voltage. , T ₂ ′
Has been corrected to.

These values t ₁ ′, t ₂ ′, t ₃ , l ₁ and l ₂ are given to the abnormality determination circuit K. This circuit K has a reference value for each value, that is, T ₁ , T ₂ ,
Remember T ₃ , L ₀ , L ₁ .

Then, it is judged whether or not the input read value exceeds these values.

That is, if the time t ₁ ′> T ₁ , it is determined that there is a defect in the closing coil 25, the trip coil 32, or the periphery thereof.

If time t ₂ ′> T ₂ , it is determined that there is a problem in the system from the lock pin 31 to the removal of the latch 33.

If time t ₃ > T ₃ , it is determined that there is a problem in the drive part of the shutoff part such as the air system or the spring system.

If the angle l ₁ > L ₀ or l ₂ <L _1, it is considered that the movement of the movable contactor 2 is hindered, or the stroke is insufficient, and there is a problem in the drive part of the shutoff part as above. to decide.

When any one of these defects, that is, a sign of abnormality is detected, the abnormality determination circuit K gives a signal to the alarm display circuit Q via the OR circuit OR.

The circuit Q informs the maintenance personnel by an appropriate means such as an alarm and display.

In this way, effective preventive maintenance can be achieved.

The reference value held by the circuit K may be a constant value that is common to all, but based on the initial value (manufacturing head initial value) of each value t _{1 to} l ₂ in each circuit breaker, a coefficient is added to this. It may be multiplied.

Further, when the control power source E having a very small voltage fluctuation is used, the correction circuit H in the evaluator 58 is unnecessary, and naturally, the monitoring of the power source voltage is also unnecessary.

Further, instead of the optical rotary encoder, a magnetic field sensor such as a magnetic field sensor that can detect the movement of the movable contactor in a non-contact manner may be used. In short, any device that can detect the movement of the movable contactor can be used.

The evaluation of l ₁ > L ₀ and l ₂ > L ₁ is not always necessary and may be omitted depending on the case.

〔The invention's effect〕

According to the present invention, since the current waveforms of the closing coil and the trip coil are added to the stroke of the movable contact derived from the motion of the rotary operation shaft, the auxiliary switch is not used.
The sign of abnormality of the circuit breaker can be grasped with high accuracy.

Moreover, the rising point, the minimum point, the rotation start point of the rotary operation axis, the predetermined angle rotary point of the rotary operation axis, and the full-angle rotary point of the rotary operation axis are respectively extracted and the time and distance between the points are calculated. Since the comparison is made with the reference value, it is possible to distinguish in which part of the circuit breaker the symptom of the abnormality has occurred, and it is easy to handle.

[Brief description of drawings]

1 to 4 are for explaining the present invention.
FIG. 3 is a simplified configuration diagram showing one example of circuit breakers, FIG. 2 is a schematic electric diagram showing one embodiment of the present invention, and FIG. 3 is a diagram showing operation strokes and control current waveforms of circuit breakers. FIG. 4 is an electric diagram showing an example of the evaluator, and FIG. 5 is a waveform diagram showing the relationship between the operation stroke and the control current for explaining the operation of the conventional device. 2: Movable contactor, 7: Rotating operation axis 51: Disc, 55, 56: Optical cable 57: Monitoring station, 58: Evaluator

Claims (1)

[Claims] 1. A means for detecting rotation of a rotary operation shaft for operating a movable contact in a circuit breaker, a means for detecting a waveform of a control current for operating the circuit breaker, and both of the detection means. Means for transmitting a detection result to a monitoring station, and a rising point, a minimum point, and a rotation start point of the rotary operation shaft of the control current waveform from the detection signals by the both detecting means arranged and transmitted at the monitoring station. , The preset predetermined angle turning points are respectively taken out, the time between the respective points is recognized, and each time is compared and stored with each reference value as a maintenance level, and between the rising point and the minimum point of the waveform of the control current. When the time exceeds the reference value, the time between the minimum point of the waveform of the control current and the rotation start point of the rotary operation shaft is used as a reference as an indication of abnormality of the closing coil and trip coil system of the circuit breaker. When the value is exceeded, the chain of circuit breakers If the time between the rotation start point of the rotary operation shaft and the preset predetermined angle rotation point exceeds the reference value as a symptom of a system abnormality until the latch is removed from the pin, a circuit breaker Predictive maintenance device for circuit breakers, which includes an evaluator that issues an alarm as a sign of an abnormality in the drive section of the circuit breaker.