JPH0956018A - Operation monitor for power switchgear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an operation monitor for a power switchgear excellent in durability, noise resistance and reliability and having a self-diagnosis function for detecting abnormality of the sensor itself. SOLUTION: A magnetic object 37 to be detected is fixed to an operating part interlocked with the switching operation of an operating mechanism, i.e., an operating part to be monitored, and a switching position sensor 36 comprising a magnetic sensor 22 and a permanent magnet 20 is disposed at a position facing the object 37 under a throw-in state and a tripping state of a power switchgear. When the object 37 is located closely to the switching position sensor 36, the switching position sensor 36 alters the distribution of magnetic field of the permanent magnet 20 by means of the magnetism of the object 37. Consequently, output from the magnetic sensor 22 is altered and converted into an optical output signal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation monitoring apparatus for an electric power switchgear for detecting and monitoring an opening / closing operation state of an electric power switchgear, and more particularly to an object to be detected attached to an operation part to be monitored. The present invention relates to an operation monitoring device for an electric power switchgear that includes an open / close position sensor that detects the position of the switch.

[0002]

2. Description of the Related Art Generally, in electric power equipment such as a substation, an overhead line drawn from an overhead power transmission line from a power station adjacent to the substation is connected to a bushing, and the overhead line from the bushing is used for a power switchgear. Is connected to the transformer via. In such electric power equipment, the electric power switchgear is interposed between the bushing and the transformer to open and close the electric circuit when an abnormal current is generated or during inspection work.

Various types of power switchgear are known, one of which is a gas-insulated switchgear. The gas-insulated switchgear uses SF ₆ gas, which has an insulation capacity several times that of air, and has the advantages of superior insulation performance and arc-extinguishing performance compared to other switchgear, and easy miniaturization. are doing. Further, the gas-insulated switchgear has all its charging parts completely housed in the metal container, so it is unlikely to be affected by the external environment and the arc extinguishing medium will not be ejected to the outside.
The high sealing performance of such a gas-insulated switchgear, together with the miniaturization of the device, is an excellent advantage in consideration of environmental harmony. As a result, in recent years most substations have come to use gas-insulated switchgear.

Conventional Example of Switchgear for Electric Power Here, as an example of the above gas-insulated switchgear,
A conventional puffer type power switchgear will be specifically described with reference to FIG. FIG. 11 shows an example of the puffer type power switchgear 1 arranged vertically. This power switchgear 1 has a sealed case 2 containing SF ₆ gas.
A fixed electrode 3 is provided in the sealed case 2.
The movable electrode 4 is arranged so as to operate relatively. A puffer mechanism 5 is additionally formed on the movable electrode 4. When an arc is generated between the electrodes 3 and 4 when the fixed electrode 3 and the movable electrode 4 are opened and closed, the puffer mechanism 5 blows an insulating gas compressed between the electrodes 3 and 4 to extinguish the arc. Is configured.

Further, an operating rod 7 is attached to the movable electrode 4 via an insulating rod 6. An operation piston 9 of an operation mechanism 8 is connected to the operation rod 7 via a metal flange 16, and the movable electrode 4 is opened and closed by the vertical movement of the operation piston 9. The operation piston 9 is moved by the opening operation of the trip valve 12 and the closing valve 13 of the hydraulic system having the accumulator 10 and the hydraulic pump 11, and performs the tripping operation and the closing operation.

Operation monitoring device equipped with non-contact proximity sensor By the way, at the present time when the demand for electric power is increasing, the electric power system needs high voltage and large current transmission. It is difficult to acquire land for construction of equipment. Under such circumstances, there is an increasing demand for a gas-insulated switchgear that is small in size and has improved withstand voltage characteristics and is excellent in safety. Therefore, conventionally, for the purpose of predicting an abnormality in the opening / closing section, an operation monitoring device 14 for the power switchgear for detecting and monitoring the opening / closing operation is installed.

The operation monitoring device 14 is specifically attached to the operating mechanism 8. That is, as shown in FIG. 11, a monitoring case 15 is provided in a part of the operating mechanism 8 so as to house the metal flange 16. The sensor mounting plate 18 is fixed to the side surface of the monitoring case 15,
On the upper side and the lower side of the sensor mounting plate 18,
Contactless proximity sensors 17a and 17b are attached.

More specifically, these proximity sensors 17a,
The metal flange 16 is configured to be sensitive to the approach of the metal flange 16 by using the metal flange 16 as an object to be detected. The "object to be detected" referred to here is attached to a predetermined position of the monitoring target operation part, which is an operation part linked to the opening / closing operation of the operation mechanism 8 of the power switchgear 1, and is attached to the monitoring target operation part. 1 shows an object configured to move in response to a movement of a part of the proximity sensor 17
It means the direct position detection target of a and 17b. In the power switchgear 1 of FIG. 11, one of the proximity sensors 1a and 17b detects the position of the metal flange 16 that is the object to be detected by the pair of proximity sensors 17a and 17b.
7a detects the closed state of the movable electrode 4, and the proximity sensor 17b on the other side detects the open state of the movable electrode 4.

Further, these proximity sensors 17a, 17b
The detection signal output from the proximity sensor 17 is
Cables 19a and 19b such as twisted pair wires connected to a and 17b are transmitted to a relay board (not shown) and serve as input signals to the sensor receiver and the measuring unit in the relay board. As such a contactless proximity sensor, there are sensors having various operating principles, for example, a sensor utilizing high frequency oscillation. This sensor utilizes that the oscillation is stopped by a change in the inductance (L) of the sensor circuit and a change in the loss when a metal, which is an object to be detected, approaches the oscillation coil.

The contactless proximity sensor 17a as described above,
In the operation monitoring device using 17b, the sensor 17
Since a and 17b and the object to be detected (metal flange 16) do not have mechanical contact points, wear, rust, adhesion of dust, etc. of the contact points may increase as the cumulative number of operations of the power switchgear increases. The operation does not become uncertain due to deterioration. Therefore, excellent durability can be exhibited.

However, the proximity sensors 17a, 17b
Since the signal transmission cables 19a and 19b and the power supply cable (not shown) connected to the are usually made of metal, the following problems occur. That is, when these cables are used for the operation monitoring device of the power switchgear,
In an environment such as an actual substation, noise resistance will decrease.

General Optical Open / Close Sensor In order to overcome the above-mentioned problems of the non-contact proximity sensor, an optical open / close sensor is considered as a sensor used in the operation monitoring device of the power open / close device. This optical opening / closing sensor is a sensor that detects the position of the object to be detected using light, and a reflection type sensor and a transmission type sensor are known. Among them, the reflection type optical opening / closing sensor detects the approach of the detected object by irradiating the detected object with light and collecting the reflected light at the light receiving portion. Further, in the transmission type optical opening / closing sensor, the light projecting section and the light receiving section are arranged so as to face each other, and an operation path intersecting with the light path between the light projecting section and the light receiving section is provided to detect the object to be detected. It is arranged to detect the operating state of the object to be detected by blocking light. Since all of these optical opening / closing sensors use light as the position detecting means of the object to be detected, the detection signal output from the sensor can be an optical signal. Therefore, there is an advantage that the noise resistance is improved as compared with the contactless proximity sensor described above.

[0013]

However, the above-described optical opening / closing sensor has the following problems. That is, in the case of the reflection type, since the detected object is away from the sensor, when the reflected light does not return, it is not possible to detect an abnormality such as breakage of the sensor or disconnection of the optical fiber. It was impossible to monitor. Further, in the case of the transmissive type, when the detected object blocks the transmitted light of the sensor, it is also impossible to detect the abnormality of the sensor itself,
I couldn't monitor myself. Further, in any of the methods, since the light-shielding portion and the light-receiving portion are exposed, dust or the like may be attached to the portion, resulting in contamination or dew condensation. When external influences such as contamination and dew condensation are received, the sensitivity of the optical opening / closing sensor becomes extremely low, and the detection of the state of the detected object becomes uncertain.

Generally, in the operation monitoring device for the power switchgear, the open / close position sensor for detecting the operating state of the mechanism interlocked with the opening / closing operation is a particularly important component. Therefore, it is desired that the open / close position sensor have various characteristics at the same time. In other words, it has durability that could not be ensured by a device with mechanical contacts, noise resistance that was not sufficient with a contactless proximity sensor, and it was not possible with a reflective or transmissive optical switch sensor. There has been a demand for an operation monitoring device for a power switchgear having a self-monitoring function.

Further, as the demand for the operation monitoring device for the power switchgear increases, it is required to reduce the manufacturing cost. Furthermore, in order to improve the reliability of the monitoring function, an operation monitoring device capable of performing more detailed state monitoring has been waiting.

The present invention has been proposed in view of the above circumstances, and its main purpose is to provide self-monitoring which is excellent in durability, noise resistance and reliability and which detects an abnormality of the sensor itself. An object is to provide an operation monitoring device of a power switchgear having functions.

Another object of the present invention is to provide an operation monitoring device for a power switchgear, which is intended to reduce the manufacturing cost. Further, another object of the present invention is to monitor the operation of a power switchgear for further improving reliability by obtaining data for advanced state monitoring such as detection of incomplete switching operation and incomplete tripping operation. To provide a device.

[0018]

In order to achieve the above object, the invention of claim 1 operates an electric power switchgear including a switchgear main body and an operating mechanism for opening and closing the switchgear main body. In the monitoring device, an operation part interlocking with the opening / closing operation of the operation mechanism is set as a monitoring target operation part, and a detected object having magnetism is attached to the monitoring target operation part. An opening / closing position sensor including a magnetic sensor and a permanent magnet is installed at a position facing the object to be detected, and the opening / closing position sensor is configured to detect the object to be detected when the object to be detected is located near the opening / closing position sensor. Changes the distribution of the magnetic field generated from the permanent magnet by the magnetism of the magnetic field, changes the output of the magnetic sensor by the change of the magnetic field distribution, and converts the output of the magnetic field sensor into an optical signal. Characterized in that it is configured to force.

In the opening / closing position sensor according to the first aspect of the present invention, the magnetic sensor is arranged in the magnetic field generated by the permanent magnet so that the magnetic sensor always detects a constant level magnetic field. In this state, when the switchgear for electric power performs opening / closing operation and the detected object having magnetism comes to a position facing the open / close position sensor, the magnetic field distribution of the permanent magnet changes due to the influence of the magnetism of the detected object, The magnetic sensor detects this change. Then, the output of the magnetic field sensor can be converted into an optical signal and output.

According to such an opening / closing position sensor, high durability can be ensured because it does not contact the object to be detected. Moreover, since the open / close position sensor converts the output of the magnetic field sensor into an optical signal and outputs the optical signal, excellent noise resistance can be exhibited.

Further, in the open / close position sensor of the present invention, the detection of the object to be detected is carried out based on the change in the magnetic field detected by the magnetic sensor. Therefore, the presence or absence of the object to be detected can be determined by different kinds of signals. It is possible. That is, one kind of signal (whether it is reflected light or transmitted light) like a conventional monitoring device using an optical open / close sensor.
Since the presence / absence of the sensor is not the basis of the detection judgment, the sensor can always have the self-monitoring function.

Further, since there is no light-shielding portion or light-receiving portion exposed to the outside, contamination or dew condensation does not occur on the light emitting / receiving surface unlike the light opening / closing sensor, and the state detection of the object to be detected does not become uncertain. Therefore, the reliability of the monitoring device can be improved. Moreover, since expensive optical parts are used only in the transmission part, it is possible to provide a highly functional sensor at low cost.

According to a second aspect of the present invention, the optical signal output from the open / close position sensor is composed of a frequency-modulated digital signal, and the open / close position sensor detects the presence or absence of the detected object or the polarity of the detected optical signal. It is characterized in that it is configured to have different frequencies.

According to the second aspect of the present invention, since the open / close position sensor can output optical signals of different frequencies depending on the presence or absence or the polarity of detection of the object to be detected, it is always possible to detect an abnormality in the sensor itself. It is possible to monitor.

According to a third aspect of the present invention, the object to be detected is composed of a permanent magnet, and a plurality of N poles and S poles are alternately arranged along the direction in which the object to be detected is moved by the opening / closing operation of the operating mechanism. It is characterized by being arranged.

According to the third aspect of the present invention, the object to be detected is composed of a permanent magnet, and the magnetic poles are alternated in the direction of movement of the object to be detected, such as N pole, S pole, N pole. By arranging a plurality of switches, a stroke curve showing the entire opening / closing operation state of the power switchgear can be obtained. Therefore, it is possible to obtain data for more advanced state monitoring such as detection of uncompleted opening / closing operation and uncompleted tripping operation.

According to a fourth aspect of the present invention, the object to be detected is made of a material having a high magnetic permeability, and a convex portion protruding toward the opening / closing position sensor side and a concave portion apart from the opening / closing position sensor side open / close the operating mechanism. It is characterized in that a plurality of detection objects are formed along the moving direction of the detection object.

According to the invention of claim 4, a plurality of parts which are made of a material having a high magnetic permeability and which are close to and close to the open / close position sensor with respect to the moving direction of the object to be detected are provided at regular intervals. According to claim 3, by configuring
The same effect as that of the invention can be obtained. Further, according to the invention of claim 4, since no permanent magnet is used for the object to be detected,
The monitoring device can be manufactured at a lower cost.

According to a fifth aspect of the present invention, the moving speed of the test object at the mounting position of the open / close position sensor associated with the opening / closing operation of the operating mechanism is V, and N in the detected object formed of the permanent magnets.
The distance between the pole and the S pole or the distance between the convex portion and the concave portion in the detected object made of a material having a large magnetic permeability is L, the frequency of the optical signal corresponding to the operation / non-operation of the open / close position sensor is f1,
f2, where N is the number of signal readings required for signal confirmation on the receiver side that receives the output signal from the open / close position sensor,
It is characterized in that these values are configured so as to satisfy f1, f2 ≧ NV / L.

According to the invention of claim 5, the frequencies of the optical output signals are f1 and f with the movement of the object to be detected.
2, f1, f2 ... Alternatingly. Where frequency f1
Is output the same as the number of magnetic pole pairs of the object to be detected. Therefore, by detecting and plotting the generation timing of the optical signal of the frequency f1, it is possible to draw a stroke curve showing the entire opening / closing operation state of the power switchgear. As a result, it is possible to obtain data for detecting whether the opening / closing operation has not been completed or the trip has not been completed, and for performing more advanced state monitoring.

[0031]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an operation monitoring device for a power switchgear according to the present invention will be specifically described below with reference to the drawings.

[1] First Embodiment FIG. 1 to FIG. 4 (Structure) The first embodiment includes claims 1 and 2 of the present invention and is a detection target made of a permanent magnet. Body 3
7 and an open / close position sensor 36 including the magnetic sensor 22 and the permanent magnet 20. Of these, the detected object 37
Is attached to this monitoring target operation part as an operation part to be monitored, which is an operation part interlocking with the opening / closing operation of the operation mechanism in the power switchgear, and moves in the direction of arrow A in the figure in conjunction with the opening / closing operation of the operation mechanism. It is possible.

Further, the open / close position sensor 36 detects the object 37 to be detected when the power switchgear is in the closed state and in the tripped state.
It is installed at a position facing. Here, the configuration of the open / close position sensor will be described in detail with reference to FIG. As shown in the figure, a permanent magnet 20 is provided in the opening / closing position sensor 36, and a magnetic field 2 generated by the permanent magnet 20 is provided.
The magnetic field sensor 22 is arranged in the position 1. In this embodiment, a magnetic head used for recording and reproducing a magnetic tape is used as the magnetic field sensor 22, and the inside thereof has a core 23 having a minute gap and windings 24, 25 wound around this core. It consists of and.

Of these, the amplifier 27 is connected to the terminal of the winding 24.
Further, an oscillator 26 is connected, and an AC voltage signal having a constant amplitude obtained by voltage-amplifying the output of the oscillator 26 by an amplifier 27 is applied to the terminal of the winding 24.

On the other hand, in the winding 25, a voltage whose magnitude is proportional to the voltage applied to the winding 24 and whose magnitude is determined by the magnetic field 21 is induced. That is, if the magnetic field in the portion where the magnetic field sensor 22 is installed becomes small due to some external factor, the induced voltage in the winding 25 also becomes small. A diode 28, a smoothing circuit 29, an amplifier 30, and a comparator 31 are sequentially connected to the winding 25. In such a configuration, the terminal point pressure of the winding 25 is half-wave rectified by the diode 28, further converted into a DC signal by the smoothing circuit 29, amplified by the amplifier 30, and input to the comparator 31. Has become. Further, the comparator 31 has two types of reference levels RE
The input signals are compared with F1 and REF2, and the output signals SIG1 and SIG2 are output as follows according to the comparison determination result. In case of input signal> REF1 ... SIG1 = ON, SIG2 = OFF In case of REF1 ≧ input signal> REF2 ... SIG1 = OFF, SIG2 = ON In case of REF2 ≧ input signal SIG1 = OFF, SIG2 = OFF Furthermore, the comparator 31 The frequency dividing circuit 32 is connected. An oscillator 33 and a light emitting element 34 are connected to the frequency dividing circuit 32, and an optical fiber 35 is connected to the light emitting element 34.

The frequency dividing circuit 32 outputs the output signal from the oscillator 33 and the output signals SIG1 and S from the comparator 31.
Inputs IG2 and outputs f1 and f2 obtained by dividing the frequency f0 of the oscillator 33 by the values of SIG1 and SIG2.
Is configured to occur as follows. SIG1 = ON, SIG2 = OFF ... Output frequency f2 SIG1 = OFF, SIG2 = ON ... Output frequency f1 SIG1 = OFF, SIG2 = OFF ... Output frequency 0
(No output) Further, the light emitting element 34 converts the electric signal output of the comparator 31 into an optical signal and outputs the optical signal to the outside of the opening / closing position sensor 36 via the optical fiber 35.

Next, the system configuration of the first embodiment will be described with reference to FIG. In FIG. 2, reference numeral 45 is an operating mechanism of the power switchgear, and 42 is a receiver. An operating rod 43 interlocking with the opening / closing operation is provided in the operating mechanism 45, and a fixed seat 44 is attached to the operating rod 43. The detected body 37 is fixed to the fixed seat 44. Further, the open / close position sensor 36 is installed at a position facing the detected body 37 in the “ON” state (closed state) and the “OFF” state (triggered state) of the power switchgear, respectively.

On the other hand, the receiver 42 comprises a light receiving element 38, a filter 39, a pulse period detecting circuit 40 and a judging circuit 41, and is connected to the open / close position sensor 36 by an optical fiber 35. The optical fiber 35 is configured to transmit the detection signal from the position detection sensor 36 to the receiver 42 side.

Further, FIG. 3 shows an example of the mounting structure of the opening / closing position sensor 36. A monitoring case 47 is attached to the operating mechanism 45 of the power switchgear, and a sensor mounting plate 48 is fixed to the monitoring case 47. And
The open / close position sensors 36 are installed near the upper portion and the lower portion of the sensor mounting plate 48. Also, the open / close position sensor 3
6, to connect the sensor 36 and the receiver 42,
A power cable 46 is connected together with the optical fiber 35. The power supply cable 46 supplies power for the electronic circuit of the position detection sensor 36, and like the optical fiber 35, is a connector between the position detection sensor 36 and the receiver 42 in the section "X" in FIG. It is configured to be connected.

Opening / closing position sensor 3 arranged as described above
4 shows the relationship between the change in the magnetic field distribution and the output in FIG.
This will be described with reference to FIG. First, when there is no detected body 37 at a position facing the open / close position sensor 36 (FIG. 4A), the magnetic field 21 detected by the magnetic sensor 22 is only the magnetic field generated from the permanent magnet 20, and the magnetic field is constant. is there. The output voltage of the amplifier 30 in this state is adjusted to be higher than the reference level REF1 of the comparator 31. As a result, the frequency of the optical signal output of the position detection sensor 36 becomes f2.

On the other hand, when the detection body 37 is located at a position facing the open / close position sensor 36 (FIG. 4 (B)), the N pole and S pole of the permanent magnet 20 to the S pole and N pole of the detected body 37. A magnetic field directed toward is generated, and the magnetic field 21 in the magnetic sensor 22 portion decreases accordingly. In this state, the output voltage of the amplifier 30 decreases and the reference level REF1 of the comparator 31 decreases.
It is adjusted to be smaller than REF2 and larger than REF2. As a result, the frequency of the optical signal output of the position detection sensor 36 becomes f1. Thus, the open / close position sensor 36 is a sensor that generates optical signals of different frequencies f1 and f2 depending on the presence or absence of the detected body 37.

Here, a change in the distance D (shown in FIG. 1) between the permanent magnet 20 and the object to be detected 37 has a great influence on the change in the output of the magnetic sensor 22, so that the detection characteristic of the sensor 22 is not affected. Although it is necessary to manage it, this management value is usually in the range of about 5 to 10 mm, and there is no practical problem.

In the system configuration as described above, the signal flow on the receiver 42 side is as follows. First, the optical signal received by the light receiving element 38 is converted into an electrical signal, and the noise component is removed through the filter 39.
This electric signal is then input to the pulse cycle detection circuit 40, where the interval (cycle) of the pulse signal is counted, and the result is input to the determination circuit 41. The determination circuit 41 reads the input signal a plurality of times for noise removal, and determines the frequency of the signal.

As a result, when the frequency is f1, it is determined that the position detection sensor 36 has operated ("the detected object 37 is at the position facing the position detection sensor 36"), and an operation detection signal is output. Further, when the frequency is f2, it is determined that the position detection sensor is in the inoperative state (“the detected body 37 is not at the position facing the position detection sensor 36”), and the operation detection signal is not output. Further, when the frequency is greatly deviated from f1 or f2 or there is no signal input, it is determined that the sensor is abnormal and a sensor failure signal is output.

(Operation and Effect) According to the first embodiment as described above, since the optical cable 35 is used for signal transmission of the open / close position sensor 36, excellent noise resistance can be exhibited. it can. Further, unlike the optical system opening / closing sensor, the detection of the state of the object to be detected does not become uncertain due to stains or dew on the light emitting / receiving surface, and the reliability can be improved. Further, the presence or absence of detection of the detected body 37 is converted into optical signals of different frequencies f1 and f2 and processed by the receiver 42. Therefore, it is possible to provide a self-monitoring function for constantly detecting an abnormality of the open / close position sensor 36 itself. Moreover, since expensive optical parts are used only in the transmission part, a highly functional sensor can be provided at low cost.

[2] Second Embodiment ... FIG. 5 The second embodiment shown in FIG. 5 is a modification of the first embodiment, and the first embodiment shown in FIG. Compared with the mounting direction of the detected object 50 and the opening / closing position sensor 36
Change the mounting direction of the permanent magnet 20 in the inside by 90 degrees.
The poles and the S poles are arranged in the horizontal direction (see the arrow YY in the drawing). The other structure is exactly the same as that of the first embodiment. Also in such an embodiment, it is possible to obtain the same effect as that of the first embodiment.

[3] Third Embodiment ... FIG. 6 The third embodiment shown in FIG. 6 is also a modification of the first embodiment and has a large magnetic permeability as the material of the object 51 to be detected. The structural feature is that iron, which is a material, is used and is integrally formed with a mounting seat for the operation rod 43. The other structure is the same as that of the first embodiment shown in FIG.

Even when the object 51 to be detected is made of a metal magnetic material such as iron as in the present embodiment, the operation principle of the opening / closing position sensor 36 is the same as that of the first embodiment, and the above-described operational effects are obtained. Obtainable. Further, the third embodiment has an advantage that the system can be constructed at a lower cost because no permanent magnet is used for the detected object 51.

[4] Fourth Embodiment ... FIGS. 7 to 9 (Structure) The fourth embodiment shown in FIG. 7 includes claims 3 and 5 of the present invention, and an object to be detected. 53 is composed of a permanent magnet, and a plurality of N poles and S poles are alternately arranged at regular intervals along the direction in which the detected body 53 moves by the opening / closing operation of the operating mechanism 45. . The detected body 53 is fixed to the operation rod 43 of the operation mechanism 45 via the fixed seat 52. The other configuration is the same as that of the first embodiment shown in FIG. 3, and the description is omitted here.

In the fourth embodiment, the relationship between the input signal to the comparator 31 and the optical output signal when the detector 53 moves in front of the position detecting sensor 36 will be described with reference to FIG. As shown in FIG.
3, the frequencies of the optical output signals f1, f2,
Alternately f1, f2 ... Here, the number of times the frequency f1 is output is the same as the number of magnetic pole pairs of the detected body 53. Therefore, the stroke curve as shown in FIG. 9 can be drawn by detecting and plotting the generation timing of the optical signal of the frequency f1. Here, the conditions for detecting such a frequency change are obtained as follows.

That is, when the moving speed of the detection body 53 at the mounting position of the opening / closing position sensor 36 associated with the opening / closing operation of the power switchgear is V and the gap between the magnetic poles of the detection body 53 is L,
It is necessary to determine the signal change during ΔT = L / V. Further, if the number of signal readings required for signal confirmation on the receiver 42 side is N, then ΔT becomes smaller, and ΔT becomes smaller.
= L / (NV). Since it is necessary to measure the cycles of the frequencies f1 and f2 within this time, the following conditions must be satisfied after all.

F1, f2 ≧ NV / L (1) (Operation and effect) In the fourth embodiment having such a configuration, by detecting the change of the frequency f1,
It is possible to reliably detect the position of the detected object 53. As a result, a stroke curve showing the entire opening / closing operation state of the power switchgear can be obtained. This allows
(EN) Provided is an operation monitoring device capable of detecting data of incomplete opening / closing of an opening / closing operation and uncompleted tripping, and obtaining data for more advanced state monitoring, and capable of more detailed state monitoring. it can.

[5] Fifth Embodiment ... FIG. 10 The fifth embodiment shown in FIG. 10 includes claims 4 and 5 of the present invention, and is transparent as a constituent material of the detector 54. Iron, which is a material with a high magnetic susceptibility, is used, and the detected portion 54 is moved by the opening / closing operation of the operating mechanism 45 by the convex portion 54a protruding toward the opening / closing position sensor 36 side and the concave portion 54b apart from the opening / closing position sensor 36 side. The feature is that a plurality of them are formed along the direction. Other configurations are
Except for the point that L is the distance between the convex portion 54a and the concave portion 54b in the detected object 54, the same as the fourth embodiment shown in FIG. Is.

In the fifth embodiment as described above,
In addition to obtaining the same effects as those of the fourth embodiment, there is an advantage that the system can be constructed at a lower cost because no permanent magnet is used for the detected object 54.

[6] Other Embodiments Note that the present invention is not limited to the above-described embodiments, and the arrangement location, the number of installations, and the like can be changed as appropriate, and the opening / closing position sensor can be changed. The optical signal output from the device may be an analog signal or a digital pulse signal.

[0056]

As described above, according to the operation monitoring device for the power switchgear of the present invention, since the optical cable is used for the signal transmission of the switchgear position sensor, excellent noise resistance is exhibited. It is possible to improve the reliability because the detection of the state of the detection object does not become uncertain due to the contamination of the light emitting and receiving surface or dew condensation. Furthermore, the presence or absence of the detection object can be converted into a different frequency optical signal. Since it is processed by the above, it is possible to have a self-monitoring function that constantly detects an abnormality of the sensor itself.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an opening / closing position sensor used in an operation monitoring device for a power switchgear according to a first embodiment of the present invention.

FIG. 2 is a system configuration diagram of the operation monitoring device according to the first embodiment.

FIG. 3 is a cross-sectional view showing an example of mounting the open / close position sensor according to the first embodiment.

FIG. 4 is a configuration diagram illustrating an operation principle of the opening / closing position sensor according to the first embodiment.

FIG. 5 is a sectional view showing an example of mounting an open / close position sensor according to a second embodiment of the present invention.

FIG. 6 is a sectional view showing a mounting example of an opening / closing position sensor according to a third embodiment of the present invention.

FIG. 7 is a sectional view showing an example of mounting an open / close position sensor according to a fourth embodiment of the present invention.

FIG. 8 is a characteristic diagram illustrating the relationship between the position of the detected object and the optical signal output according to the fourth embodiment.

FIG. 9 is a graph showing a stroke curve detected by the fourth embodiment.

FIG. 10 is a sectional view showing an example of mounting an open / close position sensor according to a fourth embodiment of the present invention.

FIG. 11 is a cross-sectional view showing the configuration of a conventional puffer-type power switchgear.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Puffer type power switch device 2 ... Sealing case 3 ... Fixed electrode 4 ... Movable electrode 5 ... Puffer mechanism 6 ... Insulating rod 7,43 ... Operating rod 8,45 ... Operating mechanism 9 ... Operating piston 10 10 ... Accumulator 11 ... hydraulic pump 12 ... trip valve 13 ... closing valve 14 ... operation monitoring device 15, 47 ... monitoring case 16 ... metal flange 17a, 17b ... proximity sensor 18, 48 ... sensor mounting plate 19a, 19b ... cable 20 ... permanent Magnet 21 ... Magnetic field 22 ... Magnetic sensor 23 ... Core 24, 25 ... Winding 26, 33 ... Oscillator 27, 30 ... Amplifier 28 ... Diode 29 ... Smoothing circuit 31 ... Comparator 32 ... Dividing circuit 34 ... Light emitting element 35 ... Optical fiber 36 ... Opening / closing position sensor 37, 50, 51, 53, 54 ... Detected object 38 ... Light receiving element 39 ... Filter 40 ... Scan period detection circuit 41 ... judging circuit 42 ... receiver 44, 49 ... mounting seat 46 ... Power cable 54a ... protrusion 54b ... recess

Claims (5)

[Claims] 1. An operation monitoring device for a power switchgear comprising a switchgear main body and an operation mechanism for opening and closing the switchgear main body, wherein an operation part interlocked with the open / close operation of the operating mechanism is a monitored operation. As a part, an object to be detected having magnetism is attached to this operation part to be monitored, and an opening / closing position composed of a magnetic sensor and a permanent magnet is provided at a position facing the object to be detected in the closed state and the tripped state of the power switchgear. A sensor is installed, and the open / close position sensor changes the distribution of the magnetic field generated from the permanent magnet due to the magnetism of the detected body when the detected body is located in the vicinity of the open / closed position sensor. Change the output of the magnetic sensor by the change of
Further, the operation monitoring device of the power switchgear is configured to convert the output of the magnetic field sensor into an optical signal and output the optical signal. 2. The optical signal output from the opening / closing position sensor is composed of a frequency-modulated digital signal, and the opening / closing position sensor changes the frequency of the optical signal depending on whether or not the object to be detected is detected or its polarity. The operation monitoring device for a power switchgear according to claim 1, wherein the operation monitoring device is configured as described above. 3. The object to be detected is composed of a permanent magnet, and a plurality of N poles and S poles are alternately arranged along a direction in which the object to be detected is moved by opening / closing operation of the operating mechanism. The operation monitoring device for a power switchgear according to claim 1 or 2, wherein. 4. The object to be detected is made of a material having a high magnetic permeability, and a convex portion protruding toward the open / close position sensor side and a concave portion apart from the open / close position sensor side are used to open / close the operation mechanism. 3. A plurality of objects to be detected are formed along the moving direction of the object to be detected.
An operation monitoring device for the switchgear for electric power described. 5. The moving speed of the inspection object at the mounting position of the opening / closing position sensor due to the opening / closing operation of the operation mechanism is V, and the distance between the N pole and the S pole in the object to be detected which is composed of the permanent magnets. Alternatively, the distance between the convex portion and the concave portion of the detected object made of the material having a high magnetic permeability is L, the frequencies of the optical signals corresponding to the operation and non-operation of the opening / closing position sensor are f1, f2, and the opening / closing position sensor. The number of signal readings required for signal confirmation on the receiver side receiving the output signal from
When these values are set, these values are configured to satisfy f1, f2 ≧ NV / L.
Alternatively, the operation monitoring device of the power switchgear according to item 4.