Method for measuring movement amount of movable part of gas-insulated switchgear, method for diagnosing operational deterioration of gas-insulated switchgear, and maintenance method of gas-insulated switchgear

Abstract

A method for measuring a movement amount of a movable part of a gas-insulated switchgear (100), the method comprising: installing, in a grounding switch or a disconnector (10) equipped with an inspection window (12) for allowing visual observation of the movement of a movable part (16) in a cylindrical container (11) having insulation gas encapsulated therein, an imaging unit (20) opposite to the inspection window (12); using the imaging unit to capture an image of a sliding pattern (303) that, when the movable part is moving, appears on the movable part as a result of rubbing against a current collector (21) provided to a fixation part (17) in the cylindrical container; and measuring the movement amount of the movable part on the basis of the sliding pattern imaged by the imaging unit.

Description

Method for measuring the amount of movement of a moving part of a gas-insulated switchgear, method for diagnosing operational deterioration of a gas-insulated switchgear, and method for maintaining a gas-insulated switchgear

[0001] The present invention relates to a method for measuring the amount of movement of a movable part of a gas-insulated switchgear, a method for diagnosing operational deterioration of a gas-insulated switchgear, and a method for maintaining a gas-insulated switchgear.

[0002] Gas Insulated Switchgear (GIS) is equipment installed at substations, which are relay points that deliver electricity generated at power plants to homes, factories, etc. When an abnormal current flows in the power system due to a lightning strike or other cause, this Gas Insulated Switchgear (GIS) instantly cuts off the current to protect equipment such as transformers at the substation, and then quickly turns it on to supply power.

[0003] Gas-insulated switchgear (GIS) consists of devices such as busbars (BUS), gas circuit breakers (GCB), disconnecting switches (DS), earthing switches (ES), current transformers (CT), lightning arresters (LA), and cable heads (CH). The external appearance of a gas-insulated switchgear is that of multiple connected cylindrical pressure vessels. The gas sealed in these pressure vessels can be, for example, sulfur hexafluoride (SF ６ ) is commonly used. Gas-insulated switchgear varies in size depending on the rated voltage class. Disconnectors and earthing switches are installed at a reasonable height above ground level, and in order to reduce size, their operating mechanisms are often also installed at high altitudes.

[0004] Sulfur hexafluoride (SF ６ ) is a harmless inert gas with excellent insulating properties, and has superior arc-extinguishing properties compared to other gases. However, its global warming potential is low, and it is ２ ), it is subject to gas leak management. For this reason, whether the substation is manned or unmanned, the substation manager must visually check the exterior of the gas insulated switchgear at preset intervals while the switchgear is in operation, and visually check the pressure of the gas inside with a pointer-type pressure gauge.

[0005] In addition to the above-mentioned visual inspections, gas-insulated switchgear disconnectors are also subject to general external inspections, various measurement tests, and overhaul inspections of their mechanisms. For example, inspections include a general external inspection of the disconnector operating mechanism, which is carried out once every six or twelve years, measurement of the switching time, which is carried out once every six or whenever necessary, and measurement of the switching stroke, which is carried out whenever necessary.

[0006] In addition, the disconnecting section that houses the disconnecting switch electrodes is disassembled and inspected whenever necessary, and in many cases the mechanical section is also disassembled and inspected whenever necessary.

[0007] In this way, the frequency of disassembly and inspection of the disconnectors of gas-insulated switchgear is considered low compared to other industrial machinery that is normally operated. However, measuring the stroke during the opening and closing operation of the disconnectors is important for determining the operational deterioration state of the disconnectors.

[0008] A conventional technique for measuring the opening and closing stroke of a disconnector is to attach a rotary potentiometer to the rotating shaft of the operating mechanism, and use the disconnector opening and closing command as a trigger for a waveform recorder to record the time history of the swing angle of the rotating shaft, which is then converted into the opening and closing stroke of the disconnector.

[0009] Furthermore, as a conventional technique for measuring the opening and closing stroke of a gas-insulated switchgear, for example, there is a portable motion measurement system and a motion measurement method described in Patent Document 1. Patent Document 1 discloses a technique that includes a high-speed camera that reads two-dimensional images, a lighting device, and an image processing display device, in which markers are attached to the movable and fixed parts of the switchgear, the high-speed camera captures images of the movable and fixed markers while the switchgear is in operation, and the image processing display device calculates the opening and closing stroke based on the change in position of the movable marker relative to the fixed marker.

[0010] Another prior art technique for measuring the opening and closing stroke of a gas circuit breaker is a position detection device and a switching operation characteristic measuring device using the same, as described in Patent Document 2. Patent Document 2 discloses a technique in which a reflector is fixed to a main shaft (a rod that moves linearly) that moves linearly in conjunction with the stroke of a movable electrode during the opening and closing operation of the circuit breaker, and an optical system and lighting that illuminate the movable range of the reflector are provided, and a light-receiving optical system receives light reflected by the reflector, outputs detected vibrations based on the amount of received light, and converts the detected vibrations into opening and closing strokes.

[0011] JP 2007-139596 A JP 2009-198178 A

[0012] Regarding the prior art mentioned above, for which the names of the documents are omitted, in newly delivered gas-insulated switchgear, a rotary potentiometer can be attached during the disconnector assembly stage, and stroke measurement is possible without any problems. On the other hand, in existing gas-insulated switchgear, there are issues such as the need to modify the substation site to fix the rotary potentiometer, and the fact that the disconnector is generally located at a high position, making installation difficult.

[0013] In the prior art described in Patent Document 1, stroke measurement can be performed without any problems on newly delivered gas-insulated switchgear, as described above. However, there is a problem in that for moving parts inside a pressure vessel, such as the moving electrode of a disconnecting switch, the disconnecting part must be disassembled in order to attach a marker at the substation site.

[0014] Similarly, the conventional technology described in Patent Document 2 also has the problem that the installation work is not easy because it requires disassembly of the disconnecting part of the existing disconnecting switch and the optical system to be fixed inside a pressure vessel in which a specified pressure is sealed.

[0015] Although the conventional stroke measurement technique has been described above using a disconnector as an example, the stroke measurement of a grounding switch is similar to that of a disconnector.

[0016] The present invention has been made in consideration of the above-mentioned points, and an object of the present invention is to provide a method for measuring the amount of movement of a movable part of a gas-insulated switchgear, which enables stroke measurement during switching operation without stopping the disconnecting switch (DS) or earthing switch (ES).

[0017] Another object of the present invention is to provide a method for diagnosing operational degradation of a gas-insulated switchgear using the results of measurement by a method for measuring the amount of movement of a movable part, and a method for maintaining the gas-insulated switchgear, and in particular, a method for diagnosing operational degradation of a disconnecting switch and a grounding switch of a gas-insulated switchgear, and a method for maintaining the disconnecting switch and the grounding switch.

[0018] The method of measuring the amount of movement of a movable part of a gas-insulated switchgear of the present invention, which solves the above-mentioned problems, is characterized in that, in a circuit breaker or earthing switchgear having an inspection window through which the movement of the movable part inside a cylindrical container filled with insulating gas can be visually observed, a photographing unit is installed opposite the inspection window, and when the movable part moves, a sliding pattern that appears on the movable part as it rubs against a current collector provided in a fixed part inside the cylindrical container is photographed by the photographing unit, and the amount of movement of the movable part is measured based on this photographed sliding pattern.

[0019] In addition, the method for diagnosing operational degradation of a gas-insulated switchgear of the present invention for solving the above-mentioned problems is characterized in that, in a disconnector or earthing switchgear having an inspection window through which the movement of a moving part inside a cylindrical container filled with insulating gas can be visually observed, a photographing unit is installed facing the inspection window, and as the moving part moves, the moving part rubs against a current collector provided in a fixed part inside the cylindrical container, creating a sliding pattern that appears on the moving part, the moving amount of the moving part is measured based on the photographed sliding pattern, the measured moving amount, i.e., the opening and closing stroke, is compared with the opening and closing stroke during normal operation each time the disconnector or earthing switch is inspected, and operational degradation of the disconnector or earthing switchgear is diagnosed based on the comparison result.

[0020] In addition, the maintenance method for gas-insulated switchgear of the present invention for solving the above-mentioned problems is characterized in that, in a disconnector or earthing switchgear having an inspection window through which the movement of a moving part inside a cylindrical container filled with insulating gas can be visually observed, a photographing unit is installed opposite the inspection window, the stationary state of the moving part is photographed by the photographing unit, and the time to replace the moving part is determined based on the photographed stationary state of the moving part.

[0021] According to the present invention, the stroke, which is the amount of movement of the moving part when a disconnector or earthing switch is opened or closed, can be measured non-contact without adding markers or optical systems using the existing device configuration, so stroke measurements can be easily performed on disconnectors and earthing switches regardless of whether they are newly delivered (brand new) or previously delivered products.

[0022] Problems, configurations, and effects other than those described above will become apparent from the following description of the mode for carrying out the invention (hereinafter referred to as the embodiment).

[0023] FIG. 1 is a schematic diagram illustrating an example of the configuration of a gas-insulated switchgear to which the technology of the present invention is applied. FIG. 2 is a schematic diagram illustrating an example of the configuration of the periphery of a disconnector to which a movable part movement amount measuring method according to a first embodiment of the present invention is applied. FIG. 3 is a diagram including a partial cross section illustrating a schematic configuration inside a tank of a disconnector in the gas-insulated switchgear according to the first embodiment of the present invention, where cross section (a) shows the disconnector in a closed state and cross section (b) shows the disconnector in an open state. FIG. 4 is a schematic perspective view including a partial cross section illustrating a schematic overview of the configuration of a current collector provided on a fixed-side electrode (movable-side electrode support portion) of a disconnector. FIG. 5 is a diagram illustrating the surface state of a movable-side electrode visible through an inspection window in an assembled state of the disconnector in a closed-circuit state. FIG. 6 is a diagram (part 1) illustrating a situation in which a movement trajectory is tracked by photographing a sliding pattern on the surface of a movable electrode during an opening operation of the disconnector in a movable part movement amount measuring method according to a first embodiment of the present invention. 1 is a diagram (part 2) showing a situation in which movement trajectory is tracked by photographing the sliding pattern on the movable electrode surface during a circuit-opening operation of a disconnector in a movable part movement distance measuring method according to a first embodiment of the present invention. FIG. 1 is an image diagram of a pattern when the electrode surface of the movable side electrode is carbonized after the disconnector interrupts current. FIG. 2 is an image diagram of a stroke during a circuit-opening operation of a disconnector measured (calculated) by the movable part movement distance measuring method according to a first embodiment of the present invention. FIG. 3 is an image diagram showing a normal state, a state with an operation delay, and a state where the circuit-opening stroke of a disconnector measured by the movable part movement distance measuring method according to a first embodiment of the present invention is stopped midway due to an abnormality. FIG. 4 is a diagram showing an example of a display on a display unit used when determining the time to replace a movable part in a maintenance method for gas-insulated switchgear according to a third embodiment of the present invention.

[0024] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functions or configurations are designated by the same reference numerals, and redundant description will be omitted.

[0025] [Configuration example of gas-insulated switchgear] Fig. 1 is a schematic diagram showing a configuration example of a gas-insulated switchgear to which the technology of the present invention is applied. Here, an example of the arrangement of each component of the gas-insulated switchgear from a transformer in a substation to a transmission line is shown.

[0026] The arrangement of the components of the gas-insulated switchgear is not limited to the example shown in FIG. 1, and there are a wide variety of other arrangements.

[0027] In FIG. 1 , an electric circuit coming out of a transformer (not shown) is connected to bus bars (BUS) 101, 102 on the transformer side of the gas-insulated switchgear 100, and each component of the gas-insulated switchgear 100 is arranged between these bus bars 101, 102 and the line side of a transmission line (not shown).

[0028] Specifically, pressure vessels 103 and 104 are arranged above bus bars (BUS) 101 and 102, with conductors (not shown) arranged inside them, and disconnecting switches (DS) 105 and 106 are installed above the pressure vessels 103 and 104. Also, an earthing switch (ES) 107 is provided adjacent to the pressure vessel 104. An electrically operated earthing switch can be used as the earthing switch 107, for example.

[0029] A current transformer (CT) 108 is arranged adjacent to the pressure vessel 103, and a gas circuit breaker (CB) 109 is arranged adjacent to the current transformer 108. A pressure meter (P) 110 is connected to the gas circuit breaker (CB) 109. A pressure vessel 111 is also arranged adjacent to the gas circuit breaker 109, and furthermore, equipment (not shown) is arranged between the pressure vessel 111 and the line side of the power transmission line.

[0030] In the gas-insulated switchgear 100 according to this embodiment, the pressure vessel (tank) of the gas circuit breaker 109 is configured to extend in the vertical direction, but it may also be configured to extend in a direction perpendicular to the vertical direction (horizontal direction).

[0031] The sizes of the components such as the disconnecting switches (DS) 105, 106, the earthing switch (ES) 107, the current transformer (CT) 108, the gas circuit breaker (CB) 109, and the pressure vessel 111 vary depending on the rated voltage class of the gas-insulated switchgear 100. In the gas-insulated switchgear 100 having the above-described configuration, the disconnecting switches (DS) 105, 106 and the earthing switch (ES) 107 are generally arranged at a position higher than the head of the worker 200 shown in FIG. 1 .

[0032] In the gas-insulated switchgear 100, which is designed to be compact, the electrical operating mechanisms of the disconnecting switches (DS) 105, 106 and the earthing switch (ES) 107 are located near the disconnecting section and the earthing section, so that, for example, scaffolding for working at height is required to access the operating mechanisms for external inspection of the operating mechanisms, which is performed once every six years.

[0033] Next, the technology of the present invention that is applied to the gas-insulated switchgear 100 configured as described above, that is, the technology for measuring the stroke during the opening and closing operation of the disconnecting switch and the earthing switch, will be described.

[0034] [Example 1] Example 1 is an example of measuring the stroke during the opening and closing operation of a disconnector in a gas-insulated switchgear, and its configuration is outlined in Fig. 2. The stroke during the opening and closing operation of the disconnector is the amount of movement of a movable part of the disconnector during the opening and closing operation. The movable part of the disconnector is a movable electrode. In addition to the movable electrode, a movable part connected to the movable electrode can also be the movable part.

[0035] 2 is a schematic diagram showing an example of the configuration of a disconnector and its surroundings to which the movable part movement amount measuring method according to the first embodiment of the present invention is applied. The disconnector 10 shown in FIG. 2 corresponds to the disconnectors (DS) 105 and 106 shown in FIG.

[0036] As shown in Figure 2, the disconnector 10 is composed of a cylindrical tank (cylindrical container) 11, an inspection window 12 provided on the outer periphery of the tank, and an operation box 13 containing an electric operation mechanism. The cylindrical tank 11 contains sulfur hexafluoride (SF ６ ) is sealed inside the tank (cylindrical container). The inspection window 12 is a window through which the movement of the movable parts inside the tank (cylindrical container) 11 can be visually observed. Devices 401 and 402 other than the disconnector are connected to both ends of the cylindrical tank 11 via flanges 201 and 202. In Figure 2, the dashed line X drawn on the side of the tank 11 indicates the location where the movable parts inside the tank 11 are stored.

[0037] The gas-insulated switchgear according to the first embodiment is configured to include a photographing unit 20 arranged opposite the inspection window 12, an image processing unit 30 that processes the image signal captured by the photographing unit 20, and a display unit 40 that displays the processing results of the image processing unit 30.

[0038] A high-speed camera can be exemplified as the imaging unit 20. A high-speed camera is a special video camera that can take ultra-high-speed images at thousands or tens of thousands of frames per second, whereas a general video camera takes images at 30 frames per second.

[0039] The high-speed camera is installed at a predetermined distance from the inspection window 12 using a fixing means such as a tripod (not shown), and is electrically connected to the image processing unit 30 by wiring 50. The image processing unit 30 includes a camera control unit (not shown) for controlling the high-speed camera. Since a typical high-speed camera requires a separate lighting device to capture images of the behavior of an object, a lighting device (not shown) is also installed in this embodiment.

[0040] The image processing unit 30 is configured by, for example, a CPU (Central Processing Unit) and has a function of measuring the amount of movement of a movable part inside the tank 11 using a sliding pattern (described later) photographed by the photographing unit 20 as a target. The display unit 40 displays the processing results of the image processing unit 30, for example, the measurement results of the amount of movement of a movable part inside the tank 11. Examples of the display unit 40 include a liquid crystal display and an organic EL display.

[0041] Fig. 3 is a diagram including a partial cross section that schematically shows the general configuration inside the tank 11 of the disconnector 10 in the gas-insulated switchgear 100 according to the first embodiment. The cross section (a) of Fig. 3 shows the closed state of the disconnector, and the cross section (b) of Fig. 3 shows the open state of the disconnector.

[0042] The disconnector 10 is composed of an operating mechanism 14, a motion converting mechanism 15, a movable electrode 16, a fixed electrode 17, and a movable electrode support portion 18. In this disconnector 10, the movable electrode 16 is a movable portion within the tank 11. An example of the movable portion of the disconnector 10 is a movable part connected to the movable electrode 16, such as the motion converting mechanism 15. Furthermore, the fixed electrode 17 is a fixed portion within the tank 11.

[0043] In the disconnector 10 having the above configuration, the operating mechanism 14 is housed in the operating box 13 shown in Fig. 2. A rotary motion is generated in the operating mechanism 14 by an electric motor (not shown). The motion conversion mechanism 15 converts the rotary motion generated in the operating mechanism 14 into linear motion (reciprocating motion / translational motion) and drives the movable electrode 16.

[0044] In the closed state of the disconnector 10 shown in the cross-sectional view (a) of FIG. 3 , one end of the movable electrode 16 is supported by the movable electrode support portion 18. Current collectors 21, 22 are disposed on the fixed electrode 17 and the movable electrode support portion 18 at locations (sites) that actually contact the movable electrode 16. As shown in FIG. 4 , these current collectors 21, 22 are often formed by fitting torus-shaped coil springs 24a, 24b into grooves 23a, 23b formed in the circumferential direction on the inner wall of the fixed electrode 17 (movable electrode support portion 18). Alternatively, the current collectors 21, 22 are often formed by connecting thin plates called louvers (not shown) in a torus shape. FIG. 4 is a schematic perspective view, including a partial cross section, that schematically illustrates the general configuration of the current collectors 21, 22 provided on the fixed electrode 17 (movable electrode support portion 18) of the disconnector 10.

[0045] 3 illustrates a configuration in which the current collectors 21, 22 are provided at one location each on the fixed electrode 17 and the movable electrode support portion 18, but the present invention is not limited to this configuration. For example, as shown in FIG. 4, a configuration in which the current collectors 21, 22 are provided at multiple locations (two locations in the example of FIG. 4) on one electrode may also be used.

[0046] 5 is a diagram showing the surface condition of the movable electrode 16 as seen through the inspection window 12 when the disconnector 10 is in the closed state and the disconnector 10 is assembled. When the movable electrode 16 is new, the outer circumferential surface of the movable electrode 16 is clean and does not have any scratches such as sliding marks. Although not shown in the figure, grease is applied uniformly to the surface of the movable electrode 16, which can be visually confirmed.

[0047] In a gas-insulated switchgear, when opening and closing operations are performed several to several tens of times, such as during an opening and closing test of the disconnector 10 before operation, the current collectors 21, 22 rub against the movable electrode 16, causing the current collectors 21, 22 to push aside the grease applied to the surface of the movable electrode 16, resulting in the appearance of linear sliding patterns on the surface of the movable electrode 16.

[0048] Therefore, in the movable part movement amount measuring method according to the first embodiment, a linear pattern that appears on the surface of the movable electrode 16 as the current collectors 21, 22 push aside the grease applied to the surface of the movable electrode 16 is photographed through the inspection window 12 by an imaging unit 20 such as a high-speed camera. Then, the sliding pattern photographed by the imaging unit 20 is used as a target for tracking the movement trajectory, and the movement amount of the movable electrode 16 is measured as a stroke during the opening and closing operation of the disconnector 10. In this way, by measuring the movement amount of the movable electrode 16 using the sliding pattern as a target for tracking the movement trajectory, the sliding pattern appears as the movable electrode 16 moves, and therefore the movement amount of the movable electrode 16 can be measured more accurately.

[0049] 5, points 301 and 302 are shown on the outer periphery of the movable-side electrode 16. The points 301 and 302 are points set in the image processing unit 30 in order to calibrate the distance in the captured image, and are not points actually written on the outer periphery of the movable-side electrode 16.

[0050] 6 and 7 are diagrams (parts 1 and 2) showing a situation in which the movement trajectory is tracked by photographing the sliding pattern on the surface of the movable electrode during the opening operation of the disconnector in the movable part movement amount measurement method according to Example 1. In Fig. 6 and Fig. 7, the left-hand diagrams show a representative image that is processed by the image processing unit 30 from a video captured by the photographing unit 20, such as a high-speed camera, and displayed on the display unit 40, and the right-hand diagrams show a time history waveform (displacement waveform) 300 of the displacement obtained by tracking the trajectory of the feature point 304.

[0051] 6, state diagram (a) shows the closed state of the disconnector 10 (i.e., the state before the opening operation begins), and state diagram (b) shows state 1 during the opening operation of the disconnector 10. When photographing through the inspection window 12 with a photographing unit 20 such as a high-speed camera, the fixed-side electrode 17 cannot be seen because it is outside the angle of view of the photographing unit 20, but the fixed-side electrode 17 is present on the right side of the figure, with the tip of the movable-side electrode 16 inserted. As shown in state diagram (a) in FIG. 6, a plurality of linear sliding patterns 303 appear on the surface of the movable-side electrode 16.

[0052] In the image processing unit 30, when there are multiple linear patterns appearing on the surface of the movable-side electrode 16, it is possible to switch (change) the feature points for tracking the trajectories of these multiple sliding patterns. This has the advantage that even if the shape of the linear sliding pattern 303 changes due to multiple operations, by changing the feature points for tracking the trajectory in the image processing unit 30, the change in the sliding pattern does not affect the measurement accuracy of the opening and closing strokes.

[0053] It should be noted that, when replacing the movable electrode 16, it is possible to measure the opening and closing strokes by attaching a marker to the surface of the electrode using the conventional technology disclosed in Patent Document 1. However, with the conventional technology disclosed in Patent Document 1, the marker may rub against the current collectors 21 and 22 after repeated operations, causing the printed surface of the marker to deteriorate, which may adversely affect the accuracy of measuring the opening and closing strokes.

[0054] In this embodiment, in the state diagram (a) of Fig. 6, the end points of the linear sliding pattern 303 are set as the feature points 304 for tracking the trajectory of the linear sliding pattern. By setting the end points of the linear sliding pattern 303 as the feature points 304, the trajectory of the linear sliding pattern can be tracked more reliably. Note that the feature points 304 in image processing by the image processing unit 30 are not limited to the end points of the linear sliding pattern 303, and may be a single sliding pattern or multiple sliding patterns.

[0055] 8 , when the electrode surface of the movable-side electrode 16 is carbonized after the disconnector 10 is turned to the disconnected state (i.e., after the current is interrupted), a part of the carbonized pattern 305 that appears on the electrode surface may be used as the feature point. This makes it possible to measure the amount of movement of the movable-side electrode 16 based on the carbonized pattern 305 that appears on the electrode surface of the movable-side electrode 16 after the disconnector 10 is turned to the disconnected state.

[0056] When the opening operation of the disconnector 10 begins, the movable electrode 16 moves to the left in the figure. Fig. 6B shows a state during the opening operation. As the movable electrode 16 moves, the position of the characteristic point 304 also moves in the displacement waveform shown on the right side of the state diagram (b) in Fig. 6.

[0057] FIG. 7 further shows a state where the circuit-opening operation of the disconnector 10 has progressed. In FIG. 7, state diagram (a) shows state 2 during the circuit-opening operation of the disconnector 10, and state diagram (b) shows state 3 during the circuit-opening operation of the disconnector 10. State diagram (a) in FIG. 7 shows a state where the feature point 304 set above has moved outside the field of view of the imaging unit 20, and therefore the feature point 304 has been changed to feature point 304'. Although the change from feature point 304 to feature point 304' causes discontinuity in the displacement waveform, the distance between the feature points before and after the change can be determined. Therefore, the displacement waveform can be translated in the process of measuring (calculating) the amount of movement of the movable-side electrode 16 in the image processing unit 30.

[0058] Furthermore, when the opening operation of the disconnector 10 reaches the final stage, the tip 16a of the movable electrode 16 also moves out of the field of view, so trajectory tracking is terminated. The state diagram (b) in Figure 7 shows an image taken during a time period in which the feature point 304' marked on the tip 16a of the movable electrode 16 is visible.

[0059] 9 is an image diagram of the stroke during the opening and closing operation of the disconnector 10 measured (calculated) by the movable part movement amount measuring method according to the first embodiment. The discontinuous displacement waveform is translated by the distance between the two characteristic points 304, 304' described above, and this is the opening stroke 306. Note that the stroke cannot be calculated for the portion indicated by the two-dot chain line that could not be photographed due to the angle of view from the inspection window 12, i.e., the stroke characteristic 307 that cannot be photographed. However, when determining the average speed as an evaluation index of the opening and closing characteristics, it is sufficient to use the movement amount at, for example, 20% to 80% of the total stroke.

[0060] FIG. 10 is an image diagram showing the normal state, the state with an operation delay, and the state where the circuit-breaking stroke of the disconnector is stopped midway due to an abnormality, measured by the movable part movement amount measuring method according to the first embodiment.

[0061] In the image diagram of Figure 10, waveform 308 is the opening stroke under normal conditions, which reaches the extinguishing position at a predetermined time t1. In contrast, waveform 309 is the opening stroke in a state where movement to the extinguishing position is possible despite an operational delay, and reaches the extinguishing position at time t2, which is later than time t1. In the case of the opening stroke of waveform 309, for example, as shown in Figure 8, the operation delay can be caused by carbonization of the surface of the movable electrode 16, which has interrupted the current by the disconnector 10, causing the grease to disappear, and increasing the sliding resistance between the movable electrode 16 and the fixed electrode 17 and the current collectors 21 and 22 provided on the movable electrode support part 18.

[0062] Waveform 310 is an opening stroke in a situation where the operational delay is even greater than in waveform 309, and the time it takes to reach the open position is significantly delayed. In the case of the opening stroke of waveform 310, in addition to the increase in sliding resistance between the movable electrode 16 and the current collectors 21 and 22 described above, an increase in sliding resistance and deformation of parts in the motion converting mechanism 15 and the operating mechanism 14 shown in Fig. 3 are expected. In this case, a notice that the entire disconnecting switch needs to be inspected is separately transmitted from the image processing unit 30 to the control center of the gas switchgear.

[0063] Although the present embodiment has been described with respect to abnormalities in the opening stroke, it is also possible to diagnose operational deterioration in the closing stroke in the same manner as in the opening stroke.

[0064] In the movable part movement amount measuring method according to the first embodiment, for example, the image diagram of Fig. 10 is displayed as the movement amount (stroke) of the movable part of the disconnecting switch on the display unit 40. Then, the operator can grasp the movement amount (stroke) of the movable part from the image diagram of Fig. 10 displayed on the display unit 40.

[0065] As described above, in the movable part movement amount measuring method according to the first embodiment, the movement amount of the movable side electrode 16 during the circuit-breaking operation of the disconnecting switch 10 can be calculated by using the image processing unit 30 to grasp the end points of the linear sliding pattern that appears on the electrode surface as characteristic points. Therefore, according to the movable part movement amount measuring method according to the first embodiment, the movement amount (stroke) of the movable part of the disconnecting switch 10 can be measured without any additional work being required on the disconnecting switch main body at the substation site, regardless of whether the disconnecting switch is a newly delivered product (brand new) or an already delivered product.

[0066] Although only the circuit-opening operation has been described in this embodiment, the closing stroke can also be measured (calculated) in the same manner for the circuit-closing operation in which the movable electrode 16 is inserted into the fixed electrode 17 .

[0067] [Example 2] Example 2 is an example of diagnosing operational degradation of a gas-insulated switchgear, particularly an example of diagnosing operational degradation due to aging of a disconnector in a gas-insulated switchgear. In Example 2, the method for measuring the moving amount of a movable part according to Example 1 is used to diagnose operational degradation of the disconnector due to aging.

[0068] In the method for diagnosing performance degradation of a gas-insulated switchgear according to the second embodiment, the state of performance degradation of the movable part of the disconnecting switch 10 is diagnosed from the measurement results of the method for measuring the amount of movement of a movable part according to the first embodiment, for example, the image diagram of Fig. 10 displayed on the display unit 40. For example, an operator can diagnose the state of performance degradation of the movable part of the disconnecting switch 10 from the image diagram of Fig. 10 displayed on the display unit 40. Specifically, as an example, in the image diagram of Fig. 10 displayed on the display unit 40, in the case of waveform 309, it is diagnosed that performance degradation has progressed but is within an allowable range, and in the case of waveform 310, it is diagnosed that performance degradation has progressed and is outside the allowable range.

[0069] In this example, the operator diagnoses the degree of operational deterioration by looking at the image diagram in Figure 10, but it is also possible to set a predetermined threshold value for the time t1 at which the opening stroke of waveform 308 in a normal state reaches the extinguishing position, and automatically diagnose the state of operational deterioration of the moving part based on that threshold value. The threshold value may be set, for example, for the time period between time t1 and time t2.

[0070] As described above, the performance degradation diagnosis method for gas-insulated switchgear according to the second embodiment makes it possible to diagnose the state of performance degradation of the moving part of the disconnecting switch 10 by comparing the stroke waveforms of normal operation and abnormal operation based on the measurement results of the moving part movement measurement method according to the first embodiment, that is, based on the image taken through the inspection window 12 of the disconnecting switch 10. Therefore, according to the performance degradation diagnosis method for gas-insulated switchgear according to the second embodiment, it is possible to perform performance degradation diagnosis of the disconnecting switch 10 of the gas-insulated switchgear at the substation site, regardless of whether it is a newly delivered product (brand new) or a previously delivered product.

[0071] [Example 3] Example 3 is an example in which the stationary state of a moving part is photographed by an imaging unit, and the replacement time of the moving part is determined based on the photographed state of the moving part. The maintenance method for gas-insulated switchgear according to Example 3 is a maintenance method in which the replacement time of the moving part is determined based on the stationary state of the moving part photographed in the moving part movement amount measuring method according to Example 1.

[0072] In the gas-insulated switchgear maintenance method according to the third embodiment, in the movable part movement amount measuring method according to the first embodiment, a carbonization pattern 305 (see FIG. 8 ) that appears when the disconnector 10 interrupts the current and the electrode surface of the movable electrode 16 is carbonized is captured by the image capturing unit 20 while the movable electrode 16 is in a stationary state, and the captured image is displayed, for example, on the display unit 40. Fig. 11 shows an example of the display on the display unit 40. An operator then looks at the state of the carbonization pattern 305 on the electrode surface of the movable electrode 16 when the movable electrode 16 is in a stationary state, which is displayed on the display unit 40, and determines when to replace the movable electrode 16 or the disconnector 10 including the movable electrode 16.

[0073] As described above, in the gas-insulated switchgear maintenance method according to the third embodiment, the replacement time of the moving part is determined based on the stationary state of the moving part imaged in the moving part movement amount measuring method according to the first embodiment. Therefore, according to the gas-insulated switchgear maintenance method according to the third embodiment, it is possible to determine the replacement time of the disconnecting switch 10 or the moving-side electrode 16 of the gas-insulated switchgear at the substation site, regardless of whether it is a newly delivered product (brand new) or an already delivered product.

[0074] [Modifications] The present invention is not limited to the above-described embodiments, but includes various modifications. The above-described embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations.

[0075] For example, in the above-described embodiment, the movement amount of the movable part of the disconnector (DS) in the gas-insulated switchgear is measured as a stroke during switching operation. However, for an earthing switch (ES) having the same configuration as the disconnector (DS), i.e., a movable part including a movable electrode and a fixed part including a fixed electrode, the movement amount of the movable part, the operational degradation diagnosis, and maintenance can also be performed in the same manner as for the disconnector (DS).

[0076] 3, the fixed electrode 17 is literally fixed, but as a modification, the fixed electrode 17 may not be fixed, but may be a second movable electrode configured to be movable in the opposite direction relative to the movable electrode 16, and the amount of movement of the movable electrode or the fixed electrode may be measured using a sliding pattern that appears on the second movable electrode (fixed electrode) as a target for tracking the movement trajectory. By adopting this configuration, the relative movement speed between the movable electrode and the second movable electrode (fixed electrode) increases, making it possible to more quickly measure the amount of movement.

[0077] 10...Disconnector, 11...Cylindrical tank (cylindrical container), 12...Inspection window, 13...Operation box, 14...Operation mechanism, 15...Movement conversion mechanism, 16...Movable electrode, 17...Fixed electrode, 18...Movable electrode support part, 20...Photographing part (high-speed camera), 21, 22...Current collector, 23a, 23b...Groove, 24a, 24b...Torus-shaped coil spring, 30...Image processing part, 40...Display part, 100...Gas-insulated switchgear, 101, 102... Transformer side bus (BUS), 103, 104... pressure vessel, 105, 106... disconnecting switch (DS), 107... earthing switch (ES), 108... current transformer (CT), 109... gas circuit breaker (CB), 110... pressure vessel, 201, 202... flange, 300... time history waveform of displacement obtained by tracking the trajectory of characteristic points, 301, 302... points for performing distance calibration, 303... linear sliding pattern, 304, 304'... characteristic points for tracking the trajectory of the sliding pattern, 305... carbonization pattern appearing on the electrode surface, 306... opening stroke, 307... stroke characteristics that cannot be photographed, 308... opening stroke in normal state, 309, 310... waveform, 401, 402... other equipment other than disconnecting switches

Claims

1. A method for measuring the amount of movement of a moving part of a gas-insulated switchgear, comprising the steps of: in a disconnector or earthing switch having an inspection window through which movement of a moving part inside a cylindrical container filled with insulating gas can be visually observed; installing a photographing unit facing said inspection window; photographing a sliding pattern that appears on the moving part as the moving part rubs against a current collector provided on a fixed part inside the cylindrical container when the moving part moves, and measuring the amount of movement of the moving part based on the sliding pattern photographed by the photographing unit.

2. The method for measuring the amount of movement of a moving part of a gas-insulated switchgear as described in claim 1, characterized in that the sliding pattern appearing on the moving part is a pattern in which a coating material applied to the surface of the moving part has been pushed aside as the moving part rubs against the current collector.

3. The method for measuring the amount of movement of a moving part of a gas-insulated switchgear according to claim 1, characterized in that the amount of movement of the moving part is measured based on a carbonization pattern that appears on the surface of the moving part after the disconnector or earthing switch is brought into an interrupted state.

4. The method for measuring the amount of movement of a movable part of a gas-insulated switchgear as described in claim 1, characterized in that the fixed part includes a fixed electrode that is movable in a direction opposite to the movable electrode of the movable part, and the amount of movement of the movable electrode or the fixed electrode is measured based on a sliding pattern that appears on the movable electrode or the fixed electrode.

5. The method for measuring the amount of movement of a movable part of a gas-insulated switchgear according to claim 1, characterized in that, when the sliding pattern appearing on the movable part is linear, an end point of this linear sliding pattern is set as a characteristic point for trajectory tracking.

6. The method for measuring the amount of movement of a movable part of a gas-insulated switchgear according to claim 5, characterized in that, when the sliding pattern appearing on the movable part is multiple, the characteristic points of the trajectory tracking are switched for the multiple sliding patterns.

7. A method for diagnosing operational deterioration of a gas-insulated switchgear, comprising the steps of: in a disconnector or earthing switch having an inspection window through which movement of a movable part within a cylindrical container filled with insulating gas can be visually observed; installing a photographing unit facing said inspection window; photographing a sliding pattern that appears on the movable part as the movable part rubs against a current collector provided on a fixed part within the cylindrical container when the movable part moves, measuring the amount of movement of the movable part based on the sliding pattern photographed by the photographing unit; comparing the opening and closing stroke, which is the measured amount of movement, with the opening and closing stroke during normal operation every time the disconnector or earthing switch is inspected; and diagnosing operational deterioration of the disconnector or earthing switch based on the comparison result.

8. A maintenance method for a gas-insulated switchgear, comprising the steps of: providing a photographing unit facing an inspection window in a disconnector or earthing switchgear having an inspection window through which movement of a movable part within a cylindrical container filled with insulating gas can be visually observed; photographing the stationary state of the movable part with the photographing unit; and determining when to replace the movable part based on the stationary state of the movable part photographed by the photographing unit.

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