Gas insulated switchgear

Abstract

To provide a gas insulated switchgear capable of reducing the number of components.SOLUTION: A gas insulated switchgear according to an embodiment includes a container unit, a plurality of power devices, an insulating spacer, and one partial discharge detection device. The container unit forms a plurality of sealed spaces separated by the insulating spacer. The plurality of power devices are respectively arranged in the plurality of closed spaces and connected to each other via a main busbar. The insulating spacer supports the main busbar. The one partial discharge detection device detects partial discharge inside the container unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] An embodiment of the present invention relates to a gas-insulated switchgear. [Background technology]

[0002] A gas-insulated switchgear is configured by connecting a circuit containing power devices such as circuit breakers and disconnectors to a main bus. The high-voltage live parts of each power device constituting the gas-insulated switchgear are housed in a grounded metal enclosure together with an insulating gas such as SF6 gas. Adjacent grounded metal enclosures are connected by, for example, an insulating spacer.

[0003] In order to detect an internal abnormality in a gas-insulated switchgear, for example, an internal discharge detection device is provided in the gas-insulated switchgear to detect an internal discharge occurring in the grounded metal enclosure. The internal discharge detection device has been provided, for example, in each of a plurality of insulating spacers. This has resulted in a large number of internal discharge detection devices being installed, leading to an increase in the number of parts. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3086720 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a gas-insulated switchgear that can reduce the number of parts. [Means for solving the problem]

[0006] A gas-insulated switchgear according to an embodiment includes a container, a plurality of electric power devices, an insulating spacer, and one partial discharge detection device. The container forms a plurality of sealed spaces separated by the insulating spacers. The plurality of electric power devices are arranged in each of the sealed spaces and are connected to each other via a main bus bar. The insulating spacer supports the main bus bar. The one partial discharge detection device detects partial discharges inside the container. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a layout diagram showing an example of the configuration of a gas-insulated switchgear 1 according to a first embodiment and the layout of each component. [Figure 2] FIG. 10 is a layout diagram showing an example of the configuration of a gas-insulated switchgear 2 according to a second embodiment and the layout of each component. [Figure 3] FIG. 10 is a layout diagram showing an example of the configuration of a gas-insulated switchgear 3 according to a third embodiment and the layout of each component. [Figure 4] FIG. 10 is a layout diagram showing an example of the configuration of a gas-insulated switchgear 4 according to a fourth embodiment and the layout of each component. [Figure 5] FIG. 3 is a cross-sectional view showing an example of a cone-shaped spacer 41. [Figure 6] FIG. 3 is a cross-sectional view showing an example of a post-type spacer 42. [Figure 7] FIG. 10 is a layout diagram showing an example of the configuration of a gas-insulated switchgear 5 according to a fifth embodiment and the layout of each component. [Figure 8] FIG. 2 is a configuration diagram showing an example of an antenna-type partial discharge detector 31. [Figure 9] FIG. 2 is a diagram showing an example of an embedded partial discharge detection device 32. DETAILED DESCRIPTION OF THE INVENTION

[0008] Gas insulated switchgear according to an embodiment will be described below with reference to the drawings. Gas insulated switchgear (GIS) compactly houses power equipment in a grounded metal enclosure. Gas insulated switchgear is installed, for example, by general power consumers such as factories or renewable energy power generation companies. Gas insulated switchgear may also be installed in power facilities that handle high voltages, such as substations and power plants. A power facility may also have multiple gas insulated switchgears installed.

[0009] A gas-insulated switchgear is a protective device that switches current flowing through a busbar in a gas with excellent insulating properties. A gas-insulated switchgear is manufactured by combining multiple (two or more) pieces of power equipment (components), such as a gas circuit breaker (GCB), a disconnecting switch (DS), and an earthing switch (ES). Each piece of power equipment that makes up a gas-insulated switchgear has a high-voltage charging unit. The power equipment is housed in a metallic, cylindrical, earthed metal container filled with insulating gas, such as SF6 (sulfur hexafluoride) gas.

[0010] The individual power devices that make up the gas-insulated switchgear are connected by three internal conductors or one internal conductor through which three-phase AC flows. The internal conductors are housed in a grounded metal enclosure, and the three internal conductors through which three-phase AC flows may be housed together or separately.

[0011] (First embodiment) Fig. 1 is a layout diagram showing an example of the configuration of a gas-insulated switchgear 1 of a first embodiment and the layout of each component. Fig. 1 shows an example of the configuration of a gas-insulated switchgear 1 for one line as viewed from the side and the layout of each component. The layout of the gas-insulated switchgear 1 is a one-line-one-transformer circuit (1 Line 1 Bank) in which one transformer circuit is provided on the main bus of one line circuit.

[0012] The gas-insulated switchgear 1 includes, for example, a circuit breaker 10, a transformer joint (TR-J) 12, an earthed voltage transformer (EVT) 14, a current transformer (CT) 16, a voltage transformer (VT) 18, a protection / measurement current transformer (CT) 19, a disconnecting switch 20, a lightning arrester (LA) 24, a cable head (CH) 26, a partial discharge detection device 30, an insulating spacer 40, and a grounded metal container 50.

[0013] Since each piece of power equipment is housed in a cylindrical grounded metal container 50, the reference numeral of each piece of power equipment in FIG. 1 is attached to the grounded metal container 50 housing the power equipment. An insulating spacer 40 is disposed between each pair of grounded metal containers 50 housing the power equipment. The grounded metal container 50 forms a plurality of sealed spaces separated by the insulating spacers. The plurality of power equipment is respectively disposed in the plurality of sealed spaces and connected to each other via internal conductors. The grounded metal container 50 is an example of a container portion. The container portion may be made of a material other than metal, for example, resin. The plurality of sealed spaces are arranged along the internal conductor.

[0014] The gas-insulated switchgear 1 is a so-called vertical-type gas-insulated switchgear in which a circuit breaker 10 is arranged above a circuit breaker operating mechanism 11 and extends vertically. The gas-insulated switchgear 1 protects an electrical path that transmits power from the upstream side to the downstream side in the power transmission direction. In the following description, the transformer junction 12 side of the gas-insulated switchgear 1 is referred to as the upstream side, and the cable head 26 side is referred to as the downstream side. A main bus is formed between the transformer junction 12 and the cable head 26. The transformer junction 12 and the disconnecting switch 20 comprise an earthing switch. An earthing switch is an example of a switch.

[0015] The circuit breaker 10 has the function of switching the transmission current and interrupting a fault current that enters the gas-insulated switchgear 1, thereby protecting other equipment. The circuit breaker 10 includes a switch. Connected to the upstream side of the circuit breaker 10 are, for example, a transformer junction 12, a first grounding type potential transformer 14, a current transformer 16, and a voltage transformer 18. Connected to the downstream side of the circuit breaker 10 are, for example, a disconnecting switch 20, a second grounding type potential transformer 22, a lightning arrester 24, and a cable head 26. The gas-insulated switchgear 1 has current interruption contacts (interrupting units) arranged between the voltage transformer 18 and the disconnecting switch 20. An interrupting unit is provided for each internal conductor of the three-phase AC, for example. The internal conductors are an example of main busbars.

[0016] The transformer junction 12 is provided on the upstream side of the gas-insulated switchgear 1. The transformer junction 12 connects a main bus (not shown) to the gas-insulated switchgear 1. The first earthed voltage transformer 14 has an upstream end (hereinafter referred to as one end) connected to the transformer junction 12, and a downstream end (hereinafter referred to as the other end) connected to a current transformer 16. The transformer junction 12 is arranged on one end side of the internal conductor.

[0017] The first grounded potential transformer 14 transforms, for example, the high voltage to ground flowing in the upstream electrical path into a low, easy-to-handle voltage and outputs it to a measuring instrument. One end of the primary side of the first grounded potential transformer 14 in the gas-insulated switchgear 1 is connected to an internal conductor that is connected to a transformer (not shown) through the transformer junction 12, and the other end is grounded. The secondary side of the potential transformer is connected to measuring instruments (not shown), etc. The internal conductor is further connected to an instrument current transformer 16.

[0018] The current transformer 16 converts the magnitude of the transmission current flowing in the electrical path downstream of the transformer. The secondary side of the current transformer 16 in the gas-insulated switchgear 1 is connected to a measuring instrument or the like (not shown). The internal conductor passing through the current transformer 16 is connected to the primary side of a voltage transformer 18. Two current transformers 16 are connected to one grounded metal container 50.

[0019] The potential transformer 18 converts the magnitude of the voltage flowing in the downstream electrical path and outputs it to a measuring instrument. One end of the primary side of the potential transformer 18 in the gas-insulated switchgear 1 is connected to a certain phase of the internal conductor, and the other end is connected to the internal conductor of another phase. The internal conductor is further connected to the upstream terminal of the circuit breaker 10. The potential transformer 18 converts the magnitude of the inter-phase voltage flowing in the electrical path and outputs it to a measuring instrument. The current transformer 16 and the potential transformer 18 may each be a current transformer.

[0020] The downstream terminal of the circuit breaker 20 is connected to the upstream terminal of the disconnecting switch 20 by an internal conductor. The disconnecting switch 20 separates the upstream and downstream electrical paths based on operation by an administrator, for example, when no transmission current is flowing through the internal conductor. The disconnecting switch 20 is used, for example, to disconnect power equipment from the circuit when switching the power transmission system or performing maintenance and inspection. The disconnecting switch 20 may be equipped with a grounding switch. The primary terminal of the second grounding type potential transformer 22 is connected to the internal conductor connected to the downstream side of the disconnecting switch 20. Furthermore, the internal conductor on the downstream side of the disconnecting switch 20 is connected to one end of a lightning arrester 24. The second grounding type potential transformer 22, for example, transforms the high voltage flowing in the electrical path downstream of the disconnecting switch 20 into a low, easy-to-handle voltage.

[0021] The lightning arrester 24 protects each device of the gas-insulated switchgear 1 from sudden high voltages caused by lightning or the like that enter through the electrical path to which the cable head 26 is connected. The inner conductor connected to the downstream side of the disconnecting switch 20 is connected to one end of the lightning arrester 24 and the primary side of the second earthed potential transformer 22, and further connected to the cable head 26.

[0022] The cable head 26 outputs the transmission current of each of the three phases transmitted by the upstream main bus to equipment external to the gas-insulated switchgear 1. One end of the cable head 26 is connected to the lightning arrester 24, and the other end is connected to a power cable (not shown). In the configuration of the gas-insulated switchgear 1 shown in Fig. 1, the cable head 26 outputs the current of each phase of the three-phase AC to equipment external to the gas-insulated switchgear 1 via a power cable connected to the lower side of the cable head 26. The cable head 26 is arranged at the other end of the inner conductor.

[0023] The partial discharge detection device 30 is provided in a grounded metal container 50 that houses the circuit breaker 10. The partial discharge detection device 30 has an antenna housed in the grounded metal container 50. The partial discharge detection device 30 uses the antenna housed in the grounded metal container 50 to detect high-frequency electromagnetic waves in the UHF band generated inside the grounded metal container 50.

[0024] The partial discharge detection device 30 detects partial discharges occurring inside the grounded metal container 50 based on the detection of high-frequency electromagnetic waves. An antenna is an example of a detection unit. One partial discharge detection device 30 is provided for each line circuit. The partial discharge detection device 30 may also be one that detects radio waves other than high-frequency electromagnetic waves in the UHF band.

[0025] The insulating spacer 40 is provided at the connection between the grounded metal enclosures 50 that house power equipment. The insulating spacer 40 is a so-called cone-shaped spacer, and covers the opening where adjacent grounded metal enclosures 50 are connected. An opening is formed in the center of the insulating spacer 40, through which the internal conductor passes. The space between the internal conductor and the opening is airtight. The insulating spacer 40 supports the internal conductor housed in the grounded metal enclosure 50, and separates the SF6 gas housed between adjacent grounded metal enclosures 50. The insulating spacer 40 is a spacer for supporting the internal conductor and separating the gas.

[0026] In gas-insulated switchgear, if an internal abnormality occurs, such as a defect in the insulating material, a minute cavity, or a foreign object, an electric field may concentrate at the defect, causing a partial discharge, which is a localized discharge. The occurrence of partial discharge can cause problems such as dielectric breakdown of insulating spacers.

[0027] To prevent such problems, partial discharges occurring inside the gas-insulated switchgear are detected. Conventionally, when detecting partial discharges due to internal abnormalities in the gas-insulated switchgear, a partial discharge detection device has been provided for each insulating spacer provided between the grounded metal enclosures, for example. This has required multiple partial discharge detection devices, which has tended to increase the number of parts.

[0028] In contrast, the gas-insulated switchgear 1 of the first embodiment is provided with one partial discharge detection device 30 for one line circuit. Therefore, whereas conventionally, as many partial discharge detection devices 30 as there are insulating spacers 40 were required, the first embodiment requires only one partial discharge detection device 30. This allows for a significant reduction compared to conventionally, which can contribute to a reduction in the number of parts.

[0029] In the gas-insulated switchgear 1 of the first embodiment, the partial discharge detection device 30 is provided in the grounded metal container 50 that houses the circuit breaker 10. The circuit breaker 10 is placed at a position where the number of spacers in the gas-insulated switchgear 1 is approximately equal. Therefore, the partial discharge detection device 30 can uniformly detect the occurrence of partial discharge over a wide range of the gas-insulated switchgear 1.

[0030] Furthermore, in the gas-insulated switchgear 1 of the first embodiment, high-frequency electromagnetic waves in the UHF band are detected using an antenna housed in the grounded metal container 50. This makes it possible to accurately detect partial discharges occurring over a wide range inside the gas-insulated switchgear 1. Furthermore, even if the layout of the gas-insulated switchgear 1 is expanded, it is possible to accurately detect the occurrence of partial discharges inside the gas-insulated switchgear 1.

[0031] (Second embodiment) Next, a second embodiment will be described. Fig. 2 is a layout diagram showing an example of the configuration of a gas-insulated switchgear 2 of the second embodiment and the layout of each component. The gas-insulated switchgear 2 of the second embodiment differs from the gas-insulated switchgear 1 of the first embodiment mainly in that the circuit breaker 10 is not provided.

[0032] The gas-insulated switchgear 2 includes a grounded metal enclosure 50 that houses an internal conductor and does not house any other power equipment. One end of the grounded metal enclosure 50 is connected to a potential transformer 18, and the other end is connected to a second grounded potential transformer 22. No power equipment such as a circuit breaker is housed inside the grounded metal enclosure 50. Other points are the same as those in the first embodiment.

[0033] A partial discharge detection device 30 is attached to the grounded metal enclosure 50. The partial discharge detection device 30 is disposed in the center of the internal conductor of the gas-insulated switchgear 2. Specifically, the number of insulating spacers 40 provided between the transformer joint 12 and the grounded metal enclosure 50 and the number of insulating spacers 40 provided downstream of the grounded metal enclosure 50 are both three, which are the same number.

[0034] It is preferable that the number of insulating spacers 40 provided on the upstream side of the grounded metal container 50 is the same as the number of insulating spacers 40 provided on the upstream side, but if the number of insulating spacers 40 included in the gas-insulated switchgear 1 is odd, the two numbers will not be the same. Therefore, the absolute value of the difference between the number of insulating spacers 40 provided on the upstream side of the grounded metal container 50 and the number of insulating spacers 40 provided on the upstream side may be 1, taking into account the case where the number of insulating spacers 40 included in the gas-insulated switchgear 1 is odd.

[0035] The gas-insulated switchgear 2 of the second embodiment has the same effects as the gas-insulated switchgear 1 of the first embodiment. Furthermore, the gas-insulated switchgear 2 of the second embodiment is not provided with a circuit breaker, but the partial discharge detection device 30 is disposed at the center of the plurality of insulating spacers 40. Therefore, even in a gas-insulated switchgear not provided with a circuit breaker, the partial discharge detection device 30 can uniformly detect the occurrence of partial discharge over a wide range.

[0036] (Third embodiment) Next, a third embodiment will be described. Fig. 3 is a layout diagram showing an example of the configuration of a gas-insulated switchgear 3 of the third embodiment and the layout of each component. The gas-insulated switchgear 3 of the third embodiment differs from the gas-insulated switchgear 1 of the first embodiment mainly in that a plurality of connection-grounded metal containers 60 is provided.

[0037] In the gas-insulated switchgear 3 of the third embodiment, two connection grounding metal containers 60 are interposed between the transformer junction 12 and the first grounded potential transformer 14. Furthermore, two connection grounding metal containers 60 are interposed between the lightning arrester 24 and the cable head 26. The number of insulating spacers 40 provided between the transformer junction 12 and the connection grounding metal container 60 is the same as the number of insulating spacers 40 provided downstream of the connection grounding metal container 60, both of which are five. Other points are common to the first embodiment described above.

[0038] The gas-insulated switchgear 3 of the third embodiment has the same effects as the gas-insulated switchgear 1 of the first embodiment. Furthermore, in the gas-insulated switchgear 3 of the third embodiment, the circuit breaker 10 is disposed at the center of the plurality of insulating spacers 40, and the partial discharge detection device 30 is provided in the grounded metal container 50 that houses the circuit breaker 10. Therefore, the partial discharge detection device 30 can uniformly detect the occurrence of partial discharge over a wide range.

[0039] (Fourth embodiment) Next, a fourth embodiment will be described. Fig. 4 is a layout diagram showing an example of the configuration of a gas-insulated switchgear 4 of the fourth embodiment and the layout of each component. The gas-insulated switchgear 4 of the fourth embodiment is different from the gas-insulated switchgear 3 of the third embodiment in that, of the multiple insulating spacers 40, some are cone-type spacers 41 and the remaining some are post-type spacers 42. The remaining points are common to the above-described third embodiment.

[0040] On the upstream side of the inner conductor, the insulating spacers 40 that connect the connection grounding metal containers 60 to each other and that connect the connection grounding metal container 60 to the first grounded potential transformer 14 are post-type spacers 42, and the other insulating spacers 40 are cone-type spacers 41. On the downstream side of the inner conductor, the insulating spacers 40 that connect the connection grounding metal containers 60 to each other and that connect the lightning arrester 24 to the connection grounding metal container 60 are post-type spacers 42, and the other insulating spacers 40 are cone-type spacers 41.

[0041] 5 is a cross-sectional view showing an example of a cone-shaped spacer 41. The cone-shaped spacer 41 includes a cone-shaped spacer body and a protruding portion that protrudes outward in the circumferential direction from the periphery of the spacer body. The cone-shaped spacer 41 is housed in each of the two connection grounding metal containers 60 between the two connection grounding metal containers 60.

[0042] The grounded connection metal container 60 that houses the cone-shaped spacer 41 includes, for example, a cylindrical portion 61, a one-end connection portion 62, an other-end connection portion 63, and a shield portion 64. The cylindrical portion 61 is a hollow cylindrical portion. The one-end connection portion 62 is provided at one end of the cylindrical portion 61. The other-end connection portion 63 is provided at the other end of the cylindrical portion 61.

[0043] The one-end connection portion 62 is provided with, for example, a female screw, and the other-end connection portion 63 is provided with, for example, a male screw. The other-end connection portion 63 of the connection grounding metal container 60 arranged on one end side of the internal conductor is screwed into the one-end connection portion 62 of the connection grounding metal container 60 arranged on the other end side of the internal conductor, thereby connecting adjacent connection grounding metal containers 60 to each other.

[0044] The other end connection portion 63 of the connection grounding metal container 60 on one end side of the inner conductor and the one end connection portion 62 of the connection grounding metal container 60 on the other end side can be connected by sandwiching the protruding portion of the cone-shaped spacer 41. By sandwiching the cone-shaped spacer 41 between the adjacent connection grounding metal containers 60 on one end side and the other end side of the inner conductor, the cone-shaped spacer 41 is held and fixed by the adjacent connection grounding metal containers 60.

[0045] The shielding portion 64 is ring-shaped. The outer periphery of the shielding portion 64 is held by the cone-shaped spacer 41. The internal conductor C passes through a central through-hole in the shielding portion 64. The protruding portions of the cone-shaped spacer 41 are sandwiched and fixed between adjacent connection grounding metal containers 60, thereby fixing the shielding portion 64 to the connection grounding metal containers 60. By passing the internal conductor C through the central through-hole in the shielding portion 64, the gas sealed in the connection grounding metal container 60 on one end side of the internal conductor is separated from the gas sealed in the connection grounding metal container 60 on the other end side.

[0046] 6 is a cross-sectional view showing an example of a post-type spacer 42. The post-type spacer 42 has a generally elongated shape and is erected on the bottom surface of the connection grounding metal container 60 inside the connection grounding metal container 60. An internal conductor C is placed on the post-type spacer 42. The post-type spacer 42 contacts a portion of the circumferential direction of the longitudinal side surface of the internal conductor C to support the internal conductor C from the ground side. Adjacent connection grounding metal containers 60 in the line circuit are connected and fixed by directly threading the male thread portion of the other end side connection portion 63 into the female thread portion of the one end side connection portion 62.

[0047] The fourth embodiment achieves the same effects as the gas-insulated switchgear 1 of the first embodiment. Furthermore, the gas-insulated switchgear 4 of the fourth embodiment uses post-type spacers 42 in addition to cone-type spacers 41 as the multiple insulating spacers 40. The cone-type spacers 41 separate the adjacent connection-grounded metal containers 60, which may reduce the sensitivity of the partial discharge detection device 30. In contrast, the post-type spacers 42 support the internal conductor without separating the adjacent connection-grounded metal containers 60, which may reduce the sensitivity of the partial discharge detection device 30.

[0048] From the viewpoint of separating the gas between adjacent grounded connection metal containers 60, the cone-shaped spacer 41 is preferable to the post-shaped spacer 42 as the insulating spacer 40. On the other hand, since the cone-shaped spacer 41 may reduce the sensitivity of the partial discharge detection device 30, the insulating spacer 40 may be selected taking into consideration the characteristics of both. The insulating spacer 40 may also be selected based on the limit of the detection sensitivity of the partial discharge detection device 30.

[0049] Specifically, in the design process of the gas-insulated switchgear 4, if the detection sensitivity of the partial discharge detector 30 does not reach its limit even when all the insulating spacers 40 are cone-type spacers 41, all the insulating spacers 40 are left as cone-type spacers 41. Furthermore, if all the insulating spacers 40 are cone-type spacers 41, the detection sensitivity of the partial discharge detector 30 may exceed its limit. In this case, the insulating spacers 40 are sequentially replaced from the cone-type spacers 41 to the post-type spacers 42, and either the cone-type spacers 41 or the post-type spacers 42 are selected as the insulating spacers under the condition that the detection sensitivity of the partial discharge detector 30 does not reach its limit. In this way, in the gas-insulated switchgear 4 of the fourth embodiment, the gas can be divided into many units, with the grounded metallic container 50 as the unit, while ensuring the detection sensitivity of the partial discharge detector 30.

[0050] (Fifth embodiment) Next, a fifth embodiment will be described. Fig. 7 is a layout diagram showing an example of the configuration of a gas-insulated switchgear 5 of the fifth embodiment and the layout of each component. The gas-insulated switchgear 5 of the fifth embodiment differs from the first embodiment in that a partial discharge detection device 30 is installed near a switch contact provided in the main circuit of the inner conductor C of the circuit breaker 10.

[0051] In the gas insulated switchgear 5 of the fifth embodiment, the partial discharge detection device 30 is provided between a pair of insulating spacers 40 (insulating spacers 40A, 40B) that sandwich the partial discharge detection device 30 in the internal conductor. Furthermore, the partial discharge detection device 30 is arranged at a contact S of a switch 10S that is provided in the main circuit of the internal conductor C that passes through the circuit breaker 10. The partial discharge detection device 30 is provided in the main circuit of the internal conductor C near the contact S of the switch 10S. Other points are common to the first embodiment described above.

[0052] The gas-insulated switchgear 5 of the fifth embodiment has the same effects as the gas-insulated switchgear 1 of the first embodiment. Furthermore, in the gas-insulated switchgear 5 of the fifth embodiment, a partial discharge detection device 30 is provided near the contacts of the switch. Therefore, when the partial discharge detection device 30 detects a partial discharge, it is possible to narrow down the location of the partial discharge by turning off the contacts and separating the upstream circuit from the downstream circuit.

[0053] In the fifth embodiment, the partial discharge detection device 30 is installed near the contact of the main circuit of the inner conductor C in the circuit breaker 10, but it may also be installed near the contact of the main circuit of the inner conductor C in another switch. For example, the partial discharge detection device 30 may be installed near the earthing switch provided in the disconnector 20.

[0054] For example, if the partial discharge detection device 30 detects a partial discharge when the circuit breaker 20 is in the open state, it means that a partial discharge point is present upstream of the circuit breaker 20, including the circuit breaker 20. For example, if the partial discharge detection device 30 detects a partial discharge when the circuit breaker 20 is in the closed state, and the partial discharge detection device 30 does not detect a partial discharge when the circuit breaker 20 is in the open state, it means that a partial discharge point is present downstream of the circuit breaker 20, including the circuit breaker 20.

[0055] (Sixth embodiment) Next, a sixth embodiment will be described. In the first embodiment, an antenna-type partial discharge detection device was used as the partial discharge detection device 30, but the sixth embodiment differs in that a spacer-embedded type (hereinafter referred to as "embedded type") partial discharge detection device is used as the partial discharge detection device 30. Hereinafter, both the antenna-type partial discharge detection device (hereinafter referred to as "antenna-type partial discharge detection device") and the embedded type partial discharge detection device (hereinafter referred to as "embedded type partial discharge detection device") will be described.

[0056] 8 is a configuration diagram showing an example of an antenna-type partial discharge detection device 31. The antenna-type partial discharge detection device 31 includes, for example, an antenna 71, wiring 72, and a processing unit 73. The antenna 71 is accommodated in a space formed by widening the cylindrical portion 91 of the grounded metal container 90, and is thereby housed inside the grounded metal container 90. The antenna 71 detects high-frequency electromagnetic waves in the UHF band generated inside the grounded metal container 90. The antenna 71 is arranged near the insulating spacer 40.

[0057] The antenna 71 is connected to a processing unit 73 via a wiring 72. The antenna 71 outputs information about the detected high-frequency electromagnetic waves to the processing unit 73. The processing unit 73 detects partial discharges occurring in the grounded metal container 90 based on the information about the high-frequency electromagnetic waves output by the antenna 71.

[0058] 9 is a configuration diagram showing an example of an embedded partial discharge detection device 32. The embedded partial discharge detection device 32 includes, for example, an embedded antenna 81, wiring 82, and a processing unit 83. The wiring 82 and the processing unit 83 have the same configuration as the wiring 72 and the processing unit 73 of the antenna type partial discharge detection device 31.

[0059] The embedded antenna 81 is provided inside the cone-shaped spacer 41 (insulating spacer 40). Since the cone-shaped spacer 41 is provided inside the grounded metal container 90, the embedded antenna 81 is provided inside the grounded metal container 90. The embedded antenna 81 may be made of any metal that can receive high-frequency electromagnetic waves. For example, if the cone-shaped spacer 41 includes a metal bolt or washer, the bolt or washer can be used as the embedded antenna 81.

[0060] The antenna-type partial discharge detector 31 is housed in a space formed by widening the cylindrical portion 91 of the grounded metal container 90. Therefore, the antenna-type partial discharge detector 31 can be installed at any position regardless of the position of the insulating spacer 40. This increases the degree of freedom in the installation position of the antenna-type partial discharge detector 31. Furthermore, the embedded antenna 81 can use the metal member of the insulating spacer 40 as is. This eliminates the need to provide a separate member to serve as the embedded antenna 81.

[0061] According to at least one of the embodiments described above, the number of parts can be reduced by including a container portion that forms a plurality of sealed spaces separated by insulating spacers, a plurality of power devices that are arranged in each of the plurality of sealed spaces and connected to each other via a main bus bar, insulating spacers that support the main bus bar, and one partial discharge detection device that detects partial discharge inside the container portion.

[0062] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents. [Explanation of symbols]

[0063] 1 to 5...Gas-insulated switchgear, 10...Circuit breaker, 10S...Switch, 11...Circuit breaker operating mechanism, 12...Transformer joint, 14...First earthing type voltage transformer, 16...Current transformer, 18...Voltage transformer, 20...Disconnector, 22...Second earthing type voltage transformer, 24...Lightning arrester, 26...Cable head, 30...Partial discharge detector, 31...Antenna-type partial discharge detector, 32...Embedded part Discharge detection device, 40 (40A, 40B)...insulating spacer, 41...cone-shaped spacer, 42...post-shaped spacer, 50, 90...grounded metal container, 60...connected grounded metal container, 61, 91...cylindrical portion, 62...one end side connection portion, 63...other end side connection portion, 64...shield portion, 71...antenna, 72, 82...wiring, 73, 83...processing portion, 81...embedded antenna, C...inner conductor, S...contact

Claims

1. a container portion forming a plurality of sealed spaces separated by insulating spacers; A plurality of electric power devices are arranged in each of the plurality of sealed spaces and connected to each other via a main bus; a plurality of insulating spacers supporting the main busbars; a partial discharge detection device for detecting partial discharge inside the container portion; some of the insulating spacers are first spacers that partition adjacent ones of the container portions to form the sealed space and support the main busbar; another part of the insulating spacers is a second spacer that supports the main bus bar without separating the adjacent container portions, Either the first spacer or the second spacer is selected as the insulating spacer based on a limit of detection sensitivity of the partial discharge detection device. Gas insulated switchgear.

2. The plurality of electric power devices include a circuit breaker, The partial discharge detection device is provided in the container portion that accommodates the circuit breaker.

2. The gas-insulated switchgear according to claim 1.

3. The plurality of sealed spaces are arranged along the main bus line, the partial discharge detection device is provided at a position of the main bus bar where an absolute value of a difference between the number of the insulating spacers between one end of the main bus bar and the partial discharge detection device and the number of the insulating spacers between the other end of the main bus bar and the partial discharge detection device is 1 or less.

3. The gas-insulated switchgear according to claim 1 or 2.

4. Another part of the insulating spacer contacts a circumferential part of the longitudinal side of the main busbar, The gas-insulated switchgear according to any one of claims 1 to 3.

5. The plurality of electric power devices further include a switch; The partial discharge detection device is provided between the insulating spacers that sandwich the switch in the main bus bar. The gas-insulated switchgear according to any one of claims 1 to 4.

6. The partial discharge detection device detects partial discharge inside the container by detecting high-frequency electromagnetic waves in the UHF band.

6. The gas-insulated switchgear according to claim 1 .

7. The partial discharge detection device includes a detection unit provided inside the container unit and detecting radio waves caused by partial discharge.

7. The gas-insulated switchgear according to claim 1 .

8. The partial discharge detection device includes a detection unit provided inside the insulating spacer and detecting radio waves caused by partial discharge.

7. The gas-insulated switchgear according to claim 1 .

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