JPH0883549A - Power switchgear operation monitoring device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an operation monitoring device for a power switchgear having excellent durability, noise resistance, detection accuracy and reliability. In the operation mechanism 43 of the power switchgear, an object to be detected 44 made of a permanent magnet is provided at a predetermined position of the operation mechanism 43.
The optical magnetic field sensor 40 using the Faraday effect is installed at a position corresponding to the operation of the operation mechanism 43. The optical magnetic field sensor 40 includes the sensor head 4
1. Measuring circuit 42 and optical fiber 4 connecting both
It is composed of 5. In the sensor head 41, the Faraday element 33, the polarizer 34, the analyzer 35, and the optical fiber 45 are integrally configured, and the inclination of the transmission axis of the detector 35 is set to 45 degrees.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operation monitoring device for a power switchgear for detecting and monitoring the opening / closing operation state of a power switchgear, and more particularly to an optical magnetic field sensor having a position detecting function. And an operation monitoring device for a power switchgear.

[0002]

[Prior art]

[Outline of gas-insulated switchgear that is a switchgear for electric power] At substations, an overhead line drawn from an overhead power transmission line from an adjacent power plant is connected to a bushing, and the overhead wire from this bushing passes through the switchgear. Connected to the transformer. The switchgear is a device that is interposed between the bushing and the transformer to open and close the electric circuit when an abnormal voltage is generated or during inspection work. There are various types of this switchgear, and among them, the gas-insulated switchgear that uses SF6 gas, which has an insulation capacity several times that of air, is superior in insulation performance and arc extinction performance to other switchgear, and It has an advantage that it can be easily miniaturized.

Further, in the gas-insulated switchgear, since all the charging parts are completely housed in the metal container, it is less susceptible to the influence of the external environment and the arc extinguishing medium is not ejected to the outside. Therefore, the gas-insulated switchgear is excellent in terms of environment in combination with its miniaturization. For this reason, gas-insulated switchgear is mostly used in recent substations and the like. In addition, with the recent increase in power demand, high-voltage and high-current transmission is required for the power system, but on the other hand, it is difficult to acquire construction sites for substations, etc. In addition to being excellent, there is an increasing demand for a compact and highly safe gas insulated switchgear.

As an example of such a gas-insulated switchgear, a puffer type power switchgear will be described below. As shown in FIG. 9, the puffer type power switchgear 1 includes:
The fixed electrode 3 and the movable electrode 4 are arranged so as to operate relatively in a sealed case 2 in which SF6 gas is sealed. Of these, the movable electrode 4 is additionally provided with a puffer mechanism 5. The puffer mechanism 5 is configured to blow a compressed insulating gas to extinguish the arc when the electrodes 3 and 4 are opened and closed.

An insulating rod 6 and an operating rod 7 are attached to the movable electrode 4. An operation piston 9 of an operation mechanism 8 is attached to the operation rod 7 via a metal flange 16.
Are connected, and the movable electrode 4 is opened and closed by the vertical movement of the operation piston 9. The operation piston 9 is moved downward by the opening operation of the hydraulic system trip valve 12 having the accumulator 10 and the hydraulic pump 11 so that the movable electrode 4 is put into the fixed electrode 3.

[Conventional monitoring device for power switchgear]
Further, the power switchgear 1 of this type is provided with an operation monitor 14 for detecting and monitoring the opening / closing operation for the purpose of predicting an abnormality in the breaker. The operation monitoring device 14 is specifically attached to the operation mechanism 8 and
Non-contact proximity sensor 17a for detecting the operating state of
17b is provided.

The proximity sensors 17a and 17b are constructed so that the metal flange 16 in the monitoring case 15 is used as the object to be detected, and the proximity sensor 17a, 17b is sensitive to this approach, and is mounted on the sensor mounting plate 18. Of these, the proximity sensor 17a detects the closed state of the movable electrode 4, and the proximity sensor 17a
b is configured to detect the closed state. The detection signals of the proximity sensor 17 are transmitted to the relay board via cables 19a and 19b such as twisted pair wires, respectively, and serve as input signals to the sensor receiver and the measuring section in the relay board.
As a principle of the contactless proximity sensor, for example, there is one using high frequency oscillation. This is a sensor that utilizes the fact that when a metal, which is the object to be detected, approaches the oscillation coil, oscillation stops due to changes in L and loss in the sensor circuit.

[Problems of non-contact proximity sensor] Since the non-contact proximity sensor as described above has no mechanical contact,
There is an advantage that there is no inconvenience of operation due to deterioration of contact point wear, rusting, dust adhesion, etc., which accompanies an increase in the cumulative number of operations of the power switchgear. But,
Since the signal and power cables are made of metal,
When used as an operation monitoring device for a power switchgear, it has a disadvantage of low noise resistance in an environment such as an actual substation. In order to cope with this, it has been considered to use an optical opening / closing sensor in the operation monitoring device of the power switchgear.

[Optical Open / Close Sensor] Here, the optical open / close sensor will be described. As the optical open / close sensor, a reflection type and a transmission type are known. The reflection type optical open / close sensor irradiates the detected object whose position is detected with light, and collects the reflected light at the light receiving part so that the sensor head detects the approach of the detected object. The operating state of is detected. The object to be detected is attached to a predetermined position of a mechanism that interlocks with the opening / closing operation of the power switchgear, and operates according to the operation of this mechanism to detect the position.

Further, in the transmission type optical open / close sensor, the light transmitting section and the light receiving section are arranged so as to face each other, and when the object to be detected operates, the light path between the light transmitting section and the light receiving section is blocked. A detection body is installed, and the operation state of the detection body is detected by blocking this light. Since these optical opening / closing sensors use light as the position detecting means of the object to be detected, they have an advantage that they are superior in noise resistance as compared with the contactless proximity sensor.

[Problems of Optical Open / Close Sensor] However, the optical open / close sensor has the following problems. That is, in the case of the reflection type, the sensor is damaged when the reflected light does not return because the detected object is far from the sensor.
Anomalies such as optical fiber disconnection cannot be detected, making self-monitoring impossible. Further, in the case of the transmissive type, when the object to be detected blocks the transmitted light of the sensor, it is also not possible to detect an abnormality of the sensor itself and self-monitoring is not possible.

[Optical Opening / Closing Sensor Having Self-Monitoring Function] In order to solve such a problem, Japanese Patent Laid-Open No. 5-30392
An optical opening / closing sensor capable of detecting an abnormality of the sensor itself has been proposed as disclosed in Japanese Patent Laid-Open No. This optical open / close sensor
Two light sources having different wavelengths and different phases are provided, one of which is a position detecting light source and the other is a self-monitoring light source. Further, the optical open / close sensor is provided with a position detecting section as a space on the light path, and a filter which goes in and out of the position detecting section is provided.

The filter is designed to move in and out in response to the operation of a mechanism interlocking with the opening / closing operation of the power switchgear, and serves as an object to be detected for detecting the opening / closing operation state of the power switchgear. . Further, the filter blocks the wavelength of the light source for position detection and transmits the wavelength of the light source for self-monitoring. The optical switching sensor detects the position of the filter by detecting the light from this filter and comparing the phase of the position detection light source with the received optical signal to grasp the switching operation state of the power switchgear and self-monitors. The abnormality of the sensor is detected by comparing the phase of the light source for use with the received optical signal.

[Construction of a Specific Example of Optical Opening / Closing Sensor Having Self-Monitoring Function] A technique of such an optical opening / closing sensor is shown in FIGS.
A specific description will be given using 1. Fig. 10 shows 2 different wavelengths.
FIG. 11 is a system configuration diagram of an optical opening / closing sensor that performs position detection using two lights, and FIG. 11 is a diagram showing an output waveform for each block in FIG. 10. First, in FIG.
Is a pulse generator, which generates the pulse shown in FIG. 11a.
This pulse is output by the decoder 22 shown in FIG.
As shown in 1b and 1c, it is divided into two pulse trains which are alternately generated and whose phases are different by 180 degrees. The two pulse trains are the two-wavelength light emitting diode 23 and the comparator 28.
(Both shown in FIG. 10).

The two-wavelength light-emitting diode 23 includes a light-emitting diode 30 that emits red light having a wavelength of 660 nm (pulse train in FIG. 11b) and infrared light having a wavelength of 890 nm (see FIG. 1).
And a light emitting diode 31 which emits a pulse train 1c). Furthermore, in the two-wavelength light emitting diode 23,
A light projecting fiber 24 that sends out light from the light emitting diodes 30 and 31 is connected. Further, a light receiving element 27 having a light receiving fiber 26 is provided so as to face the light projecting fiber 24, and a position detector 32 is set in a space between the light projecting fiber 24 and the light receiving fiber 26. A filter 25 that moves in and out according to a change in the opening / closing operation state of a power switchgear (not shown) is provided in the position detector 32.

The filter 25 transmits only infrared light having a wavelength of 890 nm and blocks infrared light having a wavelength of 660 nm. Here, the position where the filter 25 is inserted in the position detection unit 32 is defined as the a position, and the position deviated from the light path is defined as the b position. The light receiving element 27 has the comparator 28.
Are connected to each other, and the comparator 28 compares the two pulse trains from the decoder 22 with the output waveform of the light receiving element 27 to detect the position of the filter 25, which is an object to be detected, and to perform self-monitoring of the sensor itself. It is configured (see FIG. 10 above).

[Detection of Position of Object to be Detected (Filter)] In the optical opening / closing sensor having the above-described structure, the position detection algorithm of the filter 25 which is the object to be detected is as follows. First, as a premise, the pulse train of FIG. 11b is used as a position detection pulse train, and the pulse train of FIG. 11c is used as a self-monitoring pulse train that emits infrared light. These two-wavelength light is guided to the light receiving element 27 by the light projecting fiber 24 and the light receiving fiber 26, and both red light and infrared light are guided to the light receiving element 27 when the filter 25 is transmitted at the position b. The output waveform of the light receiving element 27 at this time is as shown in FIG. 11d. Further, when the filter 25 is shielded at the position a, only infrared light is guided to the light receiving element 27. The output waveform at this time is as shown in FIG. 11e.

The comparator 28 compares the position detecting pulse train of FIG. 11b with the output waveform of the light receiving element 27. When the filter 25 transmits light at the position b, the output waveform of the light receiving element 27 is as shown in FIG. 11d, and this output waveform includes a pulse train having the same phase as the position detecting pulse train of FIG. 11b. When the filter 25 is shielded at the position a, the output waveform of the light receiving element 27 is as shown in FIG. 11e, and this output waveform does not include the pulse train having the same phase as the position detecting pulse train of FIG. 11b.

Therefore, the comparator 28 can detect the position of the filter 25 by determining whether or not the output waveform of the light receiving element 27 includes the position detecting pulse train shown in FIG. 11b. That is, when the output waveform of the light receiving element 27 is as shown in FIG. 11d, the position detection pulse train is included, so it is determined to be the position b, and the output signal 29 as shown in FIG. 11g is output. The output waveform of the light receiving element 27 is shown in FIG.
In the case of e, since the position detection pulse train is not included, a
The position is judged and the output signal 29 is not output as shown in FIG. 11f.

[Sensor Monitoring] Next, the self-monitoring algorithm for monitoring the abnormality of the optical switching sensor itself will be described. The comparator 28 compares the self-monitoring pulse train of FIG. 11c with the output waveform of the light receiving element 27. To do. When there is no abnormality in the sensor, the output waveform of the light receiving element 27 is for self-monitoring of FIG. 11c as shown in FIGS. 11d and 11e both when the filter 25 is shielded at the position a and when light is transmitted at the position b. It includes a pulse train with the same phase as the pulse train. On the other hand, when there is an abnormality between the light emitting diode 31 that emits infrared light having a wavelength of 890 nm and the light receiving element 27, the output waveform of the light receiving element 27 does not include the self-monitoring pulse train of FIG. 11c.

Therefore, the comparator 28 includes the light receiving element 2
By determining whether or not the output waveform of 7 includes the self-monitoring pulse train of FIG. 11c, it is possible to determine whether or not there is an abnormality in the sensor such as a failure of the sensor itself or a break of the optical fiber. That is, when the output waveform of the light receiving element 27 is as shown in FIG. 11c or 11d, it is judged that there is no abnormality in the sensor because it includes the pulse train having the same phase as the self-monitoring pulse train, and the output signal 29 is output as shown in FIG. Not issued. On the other hand, when the output waveform of the light receiving element 27 does not include the self-monitoring pulse train of FIG. 11c, it is determined that the sensor has an abnormality, and the output signal 29 as shown in FIG. 11i is output.

The optical switching sensor as described above can have both the position detecting function of the object to be detected and the self-monitoring function for the sensor itself, and the operation monitoring device of the power switchgear equipped with such a sensor is At the same time that the operating state of the power switchgear is monitored, the sensor itself can also be self-monitored.

[0023]

However, the optical opening / closing sensor having both the position detecting function of the object to be detected and the self-monitoring function for the sensor itself has the following problems. That is, when the light passes from the light projecting fiber 24 to the light receiving fiber 26, the light passes through the position detecting section 32, which is a space, and it can be said that the optical opening / closing sensor has a spatial light transmitting section. That is, the projection fiber 2
The light projecting portion 4 and the light receiving portion of the light receiving fiber 26 are exposed, and there is a possibility that dust or the like may be attached to the portion to stain or condense. When an external influence such as contamination or dew condensation is received, the sensitivity of the optical opening / closing sensor becomes extremely low, and the detection of the state of the detected object becomes uncertain.

In the operation monitoring device for the power switchgear, the sensor for detecting the operating state of the mechanism interlocked with the opening / closing operation is a particularly important component. For this reason, high safety is required for the power switchgear at the present time, and for this sensor, durability that could not be ensured by devices with mechanical contacts, noise resistance that contactless proximity sensors did not have,
It is desired to have various characteristics at the same time, such as a self-monitoring function which is not provided in the reflection type or transmission type optical opening / closing sensor.

Further, the conventional sensor provided in the operation monitoring device of the power switchgear is irrespective of its system (that is, whether it has a mechanical contact or a non-contact proximity sensor, Further, even with an optical opening / closing sensor), in order to detect the operating state of the mechanism interlocking with the opening / closing operation of the power switchgear, a plurality of detection positions had to be installed. As a typical example, when detecting the “open” state and the “closed” state of the power switchgear, it is necessary to install a sensor at each detection position. Therefore, the number of sensors is large, the amount of information from the sensors is increased, the information processing is complicated, and the cost is increased.

The present invention has been proposed in view of the above circumstances, and its main purpose is to monitor the operation of a power switchgear having excellent durability, noise resistance, detection accuracy and reliability. To provide.

Another object of the present invention is to reduce the number of sensors for detecting the operating state of the mechanism interlocked with the opening / closing operation of the power switchgear, simplify the information from the sensors, and reduce the cost. An object is to provide an operation monitoring device for a power switchgear. Still another object of the present invention is to provide a power switchgear having both a position detection function for detecting an operating state of a mechanism interlocked with an opening / closing operation of the power switchgear and a self-monitoring function for detecting an abnormality of the sensor itself. To provide an operation monitoring device of the above.

[0028]

According to a first aspect of the present invention, an object to be detected having magnetism is attached to a predetermined position of a mechanism interlocking with an opening / closing operation in an operating mechanism of a power switchgear,
The optical magnetic field sensor using the Faraday effect is installed at a position corresponding to the operation of the mechanism linked to the opening / closing operation.

According to a second aspect of the present invention, the optical magnetic field sensor is
It is characterized in that it is installed individually. The invention of claim 3 is characterized in that the optical magnetic field sensors are installed in a multiplexed manner. According to a fourth aspect of the present invention, the optical magnetic field sensor includes an analyzer, and the inclination of the transmission axis of the analyzer is set to 45 degrees or in the vicinity thereof.

According to a fifth aspect of the present invention, in the operating mechanism of the electric power switchgear, one of the positions corresponding to the start end and the end of the operation of the mechanism interlocking with the opening / closing operation is provided.
A plurality of the optical magnetic field sensors are installed.
The invention according to claim 6 is characterized in that the optical magnetic field sensor is configured by integrating a Faraday element, a polarizer, an analyzer and an optical fiber. According to a seventh aspect of the present invention, the optical magnetic field sensor includes a sensor head facing the object to be detected, a transmission / reception unit that transmits and receives a signal to and from the sensor head, and a measurement circuit that measures the signal. The section between the circuit and the sensor head can be connected by a connector.

[0031]

The operation of the present invention having the above construction is as follows. First, the principle of the optical magnetic field sensor will be described with reference to FIG. The optical magnetic field sensor has a Faraday element (magneto-optical element) 33, a polarizer 34, and an analyzer 35. When the incident light Pin passes through the polarizer 34, the light becomes linearly polarized light and has a thickness L. It passes through the Faraday element 33. At this time, the plane of polarization of the Faraday element 33 rotates by an angle θ in proportion to the thickness L of the element and the external magnetic field H.
This phenomenon is the Faraday effect.

These are expressed by the following equations.

Θ = VHL V: Verdet's constant H: External magnetic field L: Faraday element thickness θ: Faraday rotation angle Therefore, when the object to be detected attached to the mechanism interlocking with the opening / closing operation of the power switchgear operates, Since the object to be detected has magnetism, the external magnetic field H that affects the optical magnetic field sensor installed at the position for detecting the position of the object to be detected changes. As a result, the Faraday rotation angle θ changes in proportion to the external magnetic field H, and thus the emitted light Pou that has passed through the analyzer 35.
The output (light intensity) of t also changes. The optical magnetic field sensor can detect the position of the magnetic detection body by comparing and calculating the output (light amount). This makes it possible to detect the operating state of the power switchgear.

In the optical magnetic field sensor using the Faraday effect as described above, light does not transmit in space. Therefore, the light projecting portion and the light receiving portion exposed in the space are not contaminated and dew condensation does not occur there, and it is possible to prevent a decrease in the light receiving level.
Further, since the optical magnetic field sensor has no mechanical contact, deterioration of the operation of the contact, such as wear, rust and adhesion of dust on the contact, does not occur. Furthermore, by using an optical magnetic field sensor, the signal transmission part near the power switchgear can be converted into an optical system, so that it is affected by noise, etc. associated with the operation of the power switchgear even in an environment such as an actual substation. Never.

Further, in order to detect the operating state of the power switchgear, at least two or more sensors had to be installed conventionally, but in the invention of claim 2, the number of optical magnetic field sensors installed is one. Even if this is the case, by comparing and calculating the output (light quantity) of this optical magnetic field sensor,
It is possible to obtain the positional relationship with the object to be detected having magnetism. Therefore, it is possible to accurately detect and monitor the operating state of the power switchgear.

Further, according to the third aspect of the invention, the optical magnetic field sensors can be constantly monitored by installing the optical magnetic field sensors in a multiplexed manner. According to the invention of claim 4, it is possible to monitor the abnormality of the optical magnetic field sensor by setting the inclination of the transmission axis of the analyzer of the optical magnetic field sensor at 45 degrees or in the vicinity thereof.

According to a fifth aspect of the invention, in the operating mechanism of the power switchgear, a plurality of optical magnetic field sensors having a position detecting function are provided at either one of the starting end and the ending end in the operation of the mechanism interlocked with the opening / closing operation. By installing them individually,
A stroke curve showing the entire opening / closing operation state of the power switchgear can be obtained. Therefore, it is possible to detect the incompletion of the opening / closing operation and the incompletion of the trip.

According to the sixth aspect of the present invention, the optical magnetic field sensor is constructed by integrating the Faraday element, the polarizer, the analyzer and the optical fiber, whereby the structure can be simplified. According to the invention of claim 7, by assembling the section between the measuring circuit and the sensor head with the connector, the assembling work can be easily performed.

[0039]

【Example】

(1) First Embodiment (1-A) Configuration of First Embodiment An embodiment of the operation monitoring device for a power switchgear according to the present invention will be specifically described below with reference to the drawings.

[System Configuration of Optical Magnetic Field Sensor] FIG.
First aspect corresponding to claims 1, 2, 4, 6 and 7 of the present invention
It is a figure which shows an Example and shows the system block diagram of the optical magnetic field sensor 40 used for the operation | movement monitoring apparatus of a power switchgear. The optical magnetic field sensor 40 is composed of a sensor head 41, a measuring circuit 42, and an optical fiber 45 connecting the both.

[Sensor Head 41] Sensor Head 41
Is installed in the operation mechanism 43 that operates in conjunction with the opening / closing operation of the power switchgear. Further, the sensor head 41 includes a Faraday element 33 and a polarizer 3 as shown in FIG.
4, the analyzer 35 and the optical fiber 45 are integrally configured. Furthermore, the inclination of the transmission axis of the detector 35 is 45.
Is set in degrees.

[Detected Object 44] A magnetic detected object 44 is mounted in the operating mechanism 43. More specifically, the operation mechanism 43 is attached to the operation rod 43a of the operation mechanism 43 of the power switchgear.
It is designed to work in conjunction with. A permanent magnet is used for the detected object 44, and the N pole and the S pole of the permanent magnet are respectively arranged at the positions corresponding to "ON" or "OFF" of the operating state of the power switchgear. Mounted so as to face each other. In FIG. 1, when the opening / closing operation is “ON (close)”, the S pole of the detected object 44 is installed so as to face the sensor head 41, and when the “OFF (open)”, the N of the detected object 44 is N. The pole is installed so as to face the sensor head 41.

[Measurement Circuit 42] The measurement circuit 42 is connected to the sensor head 41 by an optical fiber 45,
The sections are connected between the sensor head 41 and the measuring circuit 42 at the "X" and "Y" portions in FIG. Regarding the configuration of the measurement circuit 42,
More specifically, the measuring circuit 42 includes the oscillator circuit 4
6, an E / O conversion circuit 47, an O / E conversion circuit 48, and a determination circuit 49 are provided. Such a measuring circuit 42
The signal flow in is as follows. First, the oscillator circuit 4
The electric signal of a constant level output from 6 is E / O (electric / optical) converted by the E / O conversion circuit 47. The optical signal at this time becomes incident light Pin and enters the sensor head 41 through the optical fiber 45. As described with reference to FIG. 2, the incident light Pin passes through the polarizer 34, the Faraday element 33, and the detector 35, and then becomes emitted light Pout, which is emitted from the sensor head 41. Then, it enters the measuring circuit 42 again via the optical fiber 45. Optical signal is O / E conversion circuit 4
It is O / E (optical / electrical) converted by 8 and is again input to the determination circuit 49 as an electric signal.

[Overall Configuration of Operation Monitoring Device for Power Switchgear] Next, the overall configuration of the operation monitoring device for the power switchgear will be described with reference to FIG. FIG. 3 shows an example in which the optical magnetic field sensor 40 is installed in the operation monitoring device 50 of the power switchgear. A monitoring case 51 attached to the operation mechanism 43 is provided in the operation monitoring device 50, and a sensor mounting plate 52 is fixed to the monitoring case 51. The optical magnetic field sensor 40 is installed on the sensor mounting plate 52.

(1-B) Action of First Embodiment [Detection of Position of Detected Object 44] Next, the action of the first embodiment having the above-mentioned configuration will be described with reference to FIG.
As described in the principle diagram of the optical magnetic field sensor of FIG. 2, the Faraday rotation angle θ of the Faraday element 33 changes with the external magnetic field H. Therefore, with the opening / closing operation of the operating mechanism 43, the detected body 44 moves upward in FIG. 4 at the time of insertion, and the detected body 44 moves downward in FIG. 4 at the time of tripping. As a result, the N pole and the S pole of the detected object 44 operate, and the Faraday rotation angle θ of the sensor head 41 also changes. Measuring circuit 4
2 outputs the amount of light (amount of light) for comparison calculation, and the determination circuit 49 determines this, whereby the position of the detected object 44 can be detected. Thereby, the operation monitoring device 50 can detect the operation state of the power switchgear.

The relationship between the Faraday rotation angle θ and the output light intensity I0 is shown in the graph of FIG. ΘN and θS in FIG. 5 are Faraday rotation angles θ when the N pole and the S pole of the detected object 44 are closest to the sensor head 41, respectively. The amount of change in the output light intensity I0 at this time is as follows with respect to the output light intensity I0 when the sensor head 41 is not affected by the magnetic field of the detected object 44, that is, when the Faraday rotation angle θ = 0 °. .

ΘN: + ΔI0 (tripping completed) θS: −ΔI0 (closed completed) That is, the determination circuit 49 of the measuring circuit 42 outputs the output light intensity I.
When 0 is determined to be + ΔI 0, the optical magnetic field sensor 40 determines that the tripping operation of the operating mechanism 43 is completed at this point because the N pole of the detected object 44 comes closest to the sensor head 41. On the other hand, when the determination circuit 49 of the measurement circuit 42 determines that the output light intensity I0 is -ΔI0, the optical magnetic field sensor 4
In 0, the S pole of the detected object 44 comes closest to the sensor head 41, so it is determined that the closing operation of the operating mechanism 43 is completed at this point.

[Self-monitoring of the sensor itself] Further, the output light intensity I0 has the maximum value I0max when the Faraday rotation angle θN is equal to the inclination 45 ° of the transmission axis of the detector 35. On the other hand, when the Faraday rotation angle θS deviates from the inclination of the transmission axis of the detector 35 by −90 °, the output light intensity I0 becomes the minimum value I0min. However, in the first embodiment, the north pole, S
The Faraday rotation angles θN and θS when the pole is closest to the sensor head 41 must satisfy the output light intensity I0 at that time and the following condition.

-45 ° <θN, θS <45 ° (A) l ΔI0 l <l ΔI0max / 2l (B) Here, the condition (A) is that the N pole and S pole of the object to be detected 44 are the most sensor heads. It means that the Faraday rotation angles θ N and θ S when approaching 41 are not larger than the inclination of the transmission axis of the detector (set to 45 °) and do not become −45 ° or less. The condition (B) is the magnitude of the amount of change in the output light intensity I0 when the Faraday rotation angle θ is θ N and θ S (l Δ
I0 l) is smaller than the magnitude (l ΔI0max / 2l) of the output light intensity I0 when the sensor head 41 is not affected by the magnetic field of the detected object 44, that is, when the Faraday rotation angle θ = 0 °. .

Therefore, by selecting the Faraday element having the characteristics satisfying these two conditions, the output light intensity I0 never becomes 0 during the normal operation of the optical magnetic field sensor 40. Therefore, when the output light intensity I0 becomes 0, the optical magnetic field sensor 40 can detect an abnormality such as a failure of the sensor itself or a disconnection of the optical fiber 45.

(1-C) Effects of the First Embodiment According to the first embodiment as described above, an optical magnetic field sensor having no light transmission space is used as a sensor for detecting the operating state of the power switchgear. Since the 40 is used, there is no risk that the light projecting section and the light receiving section exposed in the space will be contaminated or dew will be generated there, and it is possible to prevent a decrease in the light receiving level, and to improve the detection accuracy and reliability. The property is improved.

Further, since the optical magnetic field sensor 40 has no mechanical contact, the operation of the contact is not deteriorated due to abrasion, rusting, or adhesion of dust on the contact. Further, by using the optical magnetic field sensor 40, the signal transmission part in the vicinity of the power switchgear can be made optical, so that the influence of noise and the like due to the operation of the power switchgear even in an environment such as an actual substation. It is possible to exhibit excellent noise resistance without receiving the noise.

In addition, in order to detect the operating state of the power switchgear, at least two or more sensors had to be installed in the past regardless of the sensor system, but in the first embodiment, the optical magnetic field sensor is used. 40 can calculate the relative positional relationship between the sensor head 41 and the detected body 44 by comparing and calculating the output (light quantity) from the sensor head 41, so that even if the number of sensors installed is one. Even if there is, the operating state of the operating mechanism 43 can be accurately detected. As a result, it is possible to reduce the number of sensors and the amount of information from the sensors, which allows only simple information processing to be performed and also contributes to cost reduction.

Further, in the first embodiment, the optical magnetic field sensor 40
Since the Faraday element 33, the polarizer 34, the analyzer 35, and the optical fiber 45 are integrally formed, the structure can be simplified. Further, in the first embodiment, the section between the sensor head 41 and the measuring circuit 42 can be connected by connectors at the "X" portion and the "Y" portion, so that the assembly work of the device can be easily performed. .

(2) Second Embodiment (2-A) Configuration of Second Embodiment FIG. 6 is a diagram showing a second embodiment corresponding to claim 3 of the present invention, in which the optical magnetic field sensor is duplicated. Shows a system configuration diagram when installed as a stand. In the second embodiment, two lights are provided at either one of the predetermined positions (“ON (closed)” or “OFF (disengaged) state”) of the operation mechanism 43 that is interlocked with the opening / closing operation of the power switchgear. Magnetic field sensors 51 and 52 are installed. The optical magnetic field sensors 51 and 52 include sensor heads 53 and 54, respectively, and are connected to a measurement circuit via an optical fiber 45. Sensor head 53,
54 is installed so as to face the north pole and the south pole of the detected object 44 having magnetism (in FIG. 6, the sensor 53 is the north pole).
Pole, sensor 54 is S pole).

(2-B) Operation and Effect of Second Embodiment The outputs from the sensor heads 53 and 54 are as described with reference to FIG. 4, but the optical magnetic field sensors 51 and 52 operate in either one of the operating states (""On(input)" or "Off (tripping)"
State), and is installed at a position for detecting the
Since the south poles face each other, the output light intensity I0 is positive and negative. Therefore, the soundness of the optical magnetic field sensors 51 and 52 can be confirmed by comparing the absolute values of the two outputs. Therefore, the sensor itself can have a self-monitoring function. It should be noted that although FIG. 6 exemplifies that the sensors are duplicated, they can be multiplexed depending on the importance of the reliability of the system.

(3) Third Embodiment (3-A) Configuration of Third Embodiment FIG. 7 is a diagram showing a third embodiment of the present invention corresponding to claim 5 of the present invention. In the third embodiment, three optical magnetic field sensors are attached to either one of the predetermined positions (“on (closed)” or “off (off)” state) of the operating mechanism 43 which is linked to the opening / closing operation. , Has a system configuration capable of detecting the stroke curve of the opening / closing operation. As shown in FIG. 7, as the opening / closing operation of the operation mechanism 43 is performed, the magnetic detection target object 44 causes the magnetic field sensors 55, 5 to move.
It is designed to operate near 6,57.

(3-B) Operation and Effect of the Third Embodiment In the process in which the object to be detected 44 operates in the vicinity of the optical magnetic field sensors 55, 56, 57, the outputs of the sensors 55, 56, 57 are as shown in FIG. You can draw a different stroke curve.
By determining such a stroke curve, it is possible to detect whether the opening / closing operation of the operating mechanism 43 is incomplete or not completed. Therefore, the operating state of the opening / closing operation of the operating mechanism 43 can be monitored more finely.

[0059]

As described above, according to the present invention, as the operation monitoring device for the power switchgear, a predetermined position (“on” or “off”) of the mechanism interlocked with the opening / closing operation is provided. The optical magnetic field sensor for detecting the operating state of the magnetic object attached to the (state) provides excellent durability and noise resistance, as well as a self-monitoring function for detecting abnormality of the sensor itself. In addition to having the effect, it has the following effects. That is, since the optical magnetic field sensor does not have a space for transmitting light, it is possible to provide an operation monitoring device for a power switchgear which has high detection accuracy and reliability without being affected by external influences such as contamination and dew condensation of the sensor. be able to.

By using an object to be detected having magnetism and an optical magnetic field sensor, the operating state of the power switchgear can be detected and monitored with only one sensor.
The cost can be reduced.

[Brief description of drawings]

FIG. 1 is a system configuration diagram of an optical magnetic field sensor that is a first embodiment of the present invention.

FIG. 2 is a principle diagram illustrating the Faraday effect of the optical magnetic field sensor used in the present invention.

FIG. 3 is a sectional view showing an example of mounting the optical magnetic field sensor of the first embodiment.

FIG. 4 is a configuration diagram showing the operation of the first embodiment.

FIG. 5 is a graph showing the relationship between the Faraday rotation angle θ of the optical magnetic field sensor and the output light intensity I0.

FIG. 6 is a diagram showing a second embodiment of the present invention, and is a system configuration diagram when the optical magnetic field sensor is duplicated.

FIG. 7 is a diagram showing a third embodiment of the present invention, and is a system configuration diagram in which a plurality of optical magnetic field sensors are attached.

FIG. 8 is a graph showing a stroke curve detected by the third embodiment.

FIG. 9 is a cross-sectional view showing the configuration of a conventional puffer-type power switchgear.

FIG. 10 is a system configuration diagram of an optical opening / closing sensor that performs position detection using two lights having different wavelengths.

FIG. 11 is a diagram showing output pulse waveform examples of a position detection light source and a self-monitoring light source.

[Explanation of symbols]

 33 ... Faraday element 34 ... Polarizer 35 ... Analyzer 40, 51, 52, 55, 56, 57 ... Optical magnetic field sensor 41, 53, 54 ... Sensor head 42 ... Measuring circuit 43 ... Operating mechanism 44 ... Detected object 45 ... Optical fiber 46 ... Oscillation circuit 47 ... E / O conversion circuit 48 ... O / E conversion circuit 49 ... Judgment circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsu Takimoto 2-1, Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Inside the Toshiba Hama-Kawasaki Plant (72) Inventor Seiji Wakabayashi, No. 2 Ukishima-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa No. 1 stock company Toshiba Hamakawasaki factory

Claims (7)

[Claims] 1. In the operating mechanism of the power switchgear,
Electricity characterized by attaching a magnetic object to be detected at a predetermined position of the mechanism linked to the opening / closing operation and installing an optical magnetic field sensor using the Faraday effect at a position corresponding to the operation of the mechanism linked to the opening / closing operation. Switchgear operation monitoring device. 2. The operation monitoring device for a power switchgear according to claim 1, wherein one optical magnetic field sensor is installed. 3. The operation monitoring device for a power switchgear according to claim 1, wherein the optical magnetic field sensors are installed in a multiplexed manner. 4. The electric power generator according to claim 1, wherein the optical magnetic field sensor includes an analyzer, and the inclination of the transmission axis of the analyzer is set to 45 degrees or in the vicinity thereof. Switchgear operation monitoring device. 5. In the operating mechanism of the power switchgear,
The electric power according to claim 1, 2, 3 or 4, wherein a plurality of the optical magnetic field sensors are installed at either one of the positions corresponding to the start end and the end in the operation of the mechanism interlocked with the opening / closing operation. Switchgear operation monitoring device. 6. The optical magnetic field sensor is a Faraday element,
The operation monitoring device for a power switchgear according to claim 1, 2, 3, 4 or 5, wherein the polarizer, the analyzer, and the optical fiber are integrated. 7. The optical magnetic field sensor includes a sensor head facing the object to be detected, a transmission / reception unit for transmitting / receiving a signal to / from the sensor head, and a measuring circuit for measuring the signal, 5. The section with the sensor head is connectable to a connector.
5. The operation monitoring device of the power switchgear according to 5 or 6.