JPS59136661A - Internal electric discharge detector of gas insulated hermetic electrical apparatus - Google Patents

Abstract

PURPOSE:To detect internal electric discharge with good sensitivity and to enable location of the position where said discharge arises by providing an electrode for receiving an electromagnetic wave and a photoconductor responding to electric discharge light in the bottom of a hermetic container, and taking out the detection signals thereof via a conducting part to the outside. CONSTITUTION:A gas insulated hermetic container contains gas insulated conductive parts 3 and is connected to an adjacent hermetic vessel via a gas segmenting spacer 5. A transparent protective member 6 which is an insulator, a porous receiving electrode 6, a photoconductor 8, etc. are provided in the longitudinal direction of such vessel 1 in the bottom of said vessel where conductive foreign matter generating partial electric discharge is liable to gather. The electromagnetic wave corresponding to the change in the electric field by the discharge is received and detected by the electrode 6. The photoconductor 8 such as optical fiber responds to the discharge light and the detected outputs thereof are taken out to the outside through the leading-out part of the handwheel 9 of the vessel 1. The internal discharge is thus detected with good sensitivity. The position where the partial discharge arises is located by detecting the discharge in each of the regions segmented by the spacers 5.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention provides a method for reducing the number of parts generated inside gas-insulated hermetic switchgear, gas-insulated busbars, gas-insulated cables, etc.
The present invention relates to a gas-insulated hermetically sealed electrical appliance incorporating partial discharge horizontal means for detecting IIL flow pulses and discharge light emitted accompanying the pulses.

The causes of partial sagging inside a gas insulated spacer include partial discharge in gas caused by electric field concentration on uneven or protruding parts of live parts, partial discharge in solids caused by internal defects in insulating spacers, An example of this is the fraction of conductive foreign matter in the gas that is caused by electric field levitation of unmanageable conductive foreign matter remaining inside the closed container. If magnetization occurs in the parts due to these causes, there is a risk of dielectric breakdown occurring due to unexpectedly low voltage. Therefore, during factory tests and installation, partial discharge current pulses should be taken during on-site tests, and if the cause can be eliminated. It is possible to prevent serious accidents from occurring.

A generally known method for detecting partial discharge in sealed electrical appliances is to use a sealed container as a detection electrode and insert a toroidal coil into the ground wire of the sealed container. Since it also serves as an antenna, the detection sensitivity of partial discharge is limited, and in places with high noise levels, the emitted g'a load that can be detected is 1o-8.
~10 Coulomb Chengho. Therefore, for example, a fine partial discharge (10 to 12 coulombs) generated from a conductive foreign object
cannot be detected. Methods to improve this drawback include using an embedded metal fitting provided on the side of the sealed container of the insulating spacer as the detection electrode, or providing a hand hole in the sealed container and placing the detection electrode inside the hand hole. It is known. With these methods, the partial discharge current pulse generated at the part where the detection electrode and the gas-insulated conductor ♂ face each other can be detected with high sensitivity, but the partial discharge current pulse generated at the place where the detection electrode and the gas-insulated conductor ♂ face each other is directly transmitted to the ground through the sealed container. The disadvantage of this method is that the detection sensitivity is low because only a small single-current pulse flows to the detection electrode.Therefore, the above method has the drawback that when a location where a partial discharge is predicted to occur, It may be effective when detecting electrodes are installed nearby to monitor partial discharges, but there is a risk that defects may be overlooked if the location of partial discharges cannot be predicted. Particularly, partial discharges that occur when conductive foreign matter floats in an electric field move around the closed container as the foreign matter bounces around, so the partial discharge occurs at any position in the axial direction of the closed container. It is necessary that even if a partial discharge occurs, it can be detected with approximately the same sensitivity.

The present invention has been made in view of the above-mentioned situation, and it is possible to detect the occurrence with almost the same sensitivity regardless of the location in the axial direction of the gas-insulated hermetically sealed container. The internal discharge of gas insulated and sealed appliances can be oriented.
The purpose of the present invention is to provide a turtle detection device.

According to the present invention, the above-mentioned object is achieved by disposing the gas insulated quadrielectric part in the vicinity of the inner peripheral surface of the cylindrical sealed container along the longitudinal direction of the container and at different positions in the longitudinal direction. A plurality of light guides each having a light-receiving end surface, a transparent protective member attached to an airtight container covering at least the outer circumferential side of the light guide, and a perforated plate-like member attached to the outer circumferential surface of this member. This was achieved by providing a receiving electrode and a deriving section for taking out the receiving 1g signal from this electrode and the receiving notes from the light guide to the outside of the sealed container.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 and 2 are structural diagrams of a gas-insulated sealed electrical appliance showing one embodiment of the present invention, and FIG. 1 is a cross-sectional view.

FIG. 2 is a longitudinal sectional view. In the figure, a gas insulated conductive part 3 is housed inside a cylindrical sealed container 1 via a columnar insulating spacer 2, and one end of the columnar spacer 2 is fixed to the sealed container 1 by a mounting member (not shown). ing. In addition, the axial end of the renal closure container 1 has 7 flange 4. A disk-shaped thorn or cone-shaped insulating spacer 5 for gas division and a closed container connected to each other are connected and connected to each other in an airtight manner. The gas insulated sealed appliance is filled with gas such as sulfur hexafluoride (SF6) gas at high pressure to form a gas insulated sealed appliance.The partial bottom detection means built into the gas insulated sealed appliance is part @6~ 12. 6 is a protective member made of transparent synthetic resin such as acrylic resin, and is attached to the bottom of the sealed container 1 over almost the entire length of the sealed container 1. 7 is a protective member made of transparent synthetic resin such as acrylic resin. The receiving electrode for detection is made of a metal material in the form of a perforated plate, such as a wire mesh or canned bunch metal, and is formed so as to closely cover the surface of the protective member 6, and the closed container 1 and the electrode 7 are It is insulated by the protection member 6.

Reference numeral 8 denotes a light guide such as a source fiber for detecting discharge light emitted accompanying partial discharge, and a plurality of light guides are arranged inside the transparent protective member 6 so that the light-receiving end faces are located at different positions in the length direction of the protective member. Ru. Reference numeral 9 denotes a hand hole provided at the bottom of the airtight container 1, and the lead wire 7a of the electrode 7 and the end 8a of the light guide on the light receiving element side are connected to each other. It is fixed in such a way that it passes through the 2F7 partition wall 10, and the discharge light is transmitted through the photoelectric conversion section 11, and the lead wires 7a are directly connected to the respective connectors 12, and the partial discharge current pulse and the discharged light are output as a ridge. It is configured to be taken out.

Figure 3 is a structural diagram of the partial discharge detection means in this embodiment, (a) and (b) are cross-sectional views of the detection confectionery, and (-9 is a vertical cross-sectional view. The cross-sectional shape of the protective member 6 to be fixed with an agent etc. is a flat oval shape or a sea cucumber shape with a rounded top as shown in FIG. The perforated plate-shaped electrode 7 is molded to match the shape of the transparent protective member, and the opening area is adjusted so as not to impede the transmission of electric light. It is insulated and supported with respect to the closed container 1 by using a high-quality gold sugar, precision punched metal, etc., and adhering it to the protective member 6 or fixing it with screws.

The light guide 8 is inserted into the cylindrical protective element 6 or embedded in a transparent protective element. The original fiber used as a light guide is the imitative radiation emitted accompanying partial discharge.
- It is necessary to efficiently transmit the source to the light receiving element, but since the length is about several meters, a plastic source fiber or a conduit source fiber can be used.

Further, it is preferable to attach a condenser lens to the light-receiving end face of the light guide. The position of the light-receiving end face is shown in Figure 3 (A) in 9.
As shown by B and O, as many light guides as possible are arranged at different positions along the length of the dielectric material 6, so that it can be detected even if a partial discharge occurs at any position in the axial direction of the sealed container. It is preferable to install it. Reference numeral 9 denotes a hand hole provided approximately in the center of the airtight container 1, and the light receiving element side end portion 8a of the light guide 8 extending on both sides of the hand hole is curved into an L shape and penetrates the airtight lO wall 10. is fixed. The end portion 8a of the light guide is connected to a photoelectric converter 11, and the optical signal to the light guide is converted into an electrical output to form a multi-terminal hermetic connector 1.
2 to the outside of the sealed container, and the electrode 7 is connected to the lead wire 7.
a is connected to the airtight connector 12 via the airtight bulkhead 10. Although a phototransistor or a photodetection diode can be used as the light receiving element, a photomultiplier tube is conveniently used especially when it is desired to detect minute partial discharges.

The method for attaching a partial discharge detection means to a gas-insulated sealed electrical appliance is to attach an electrode 7 and a source fiber 8 to a part of the light guide 6, and then attach a casing and a fiber that engage with the end 8a of the light guide, the lead wire 7a, and the protective member 6. Attach the airtight bulkhead lO with holes, and fill the mJ tsuba and holes with adhesive or optical material to fix the protective part. Further, the photoelectric converter 11 is inserted so that the end 8a of the light guide and the light receiving element are fully engaged, and the photoelectric converter 11 is fixed to the airtight cap 10 by a member (not shown). The partial discharge detection means assembled in this way is inserted from the inside 1141+ of the sealed container, and the O-ring 13 provided in the hand hole 9 and the airtight bulkhead 10 are engaged to maintain airtightness, and the protective member 6 is fixed in a closed container. The assembly is completed by connecting the electric circuit of the photoelectric conversion section 11 and the lead g7a to the airtight connector 12.

FIG. 4 is a mock diagram for explaining the function of the partial discharge detection means. In the figure, when a partial broadcast occurs in the closed container, a current pulse is transmitted to the capacitor cap Q1 between the gas rim conductive part 3 and the electrode 7. Consisting of nKeyongdou C2 between the f4L pole 7 and the sealed container 1, and Seigiyongdong (including the capacitance of the adjacent container) 03 between the sealed container 1 and the gas insulated 4' capacitance 3. Circulate the closed circuit. At this time, the potential drop of the capacitance C2 is detected by the detection impedance 2 connected in parallel with C2. In order to increase the detection sensitivity of the partial number 'turtle, it is preferable that C2 be as small as possible, but in general, in order to downsize the sealed container, the electrode 7 should be as tightly packed as possible.
riIM of 01 < 02 because it is installed close to each other
There is. This relationship is difficult to change even if the width of the electrode is increased and the electrode surface is expanded. Even if the structure of the g-receiving electrode is improved, it is not possible to significantly improve the detection sensitivity of partial discharges. However, by placing the electrode in a grounded sealed container, the influence of external noise is reduced.
The detection sensitivity of internal partial discharge is relatively improved. On the other hand, most of the conductive foreign substances exist in the lower part of the closed container. By providing the receiving electrode 7 at the bottom of the sealed container so as to extend along almost the entire length of the sealed container, the conductive foreign matter and the receiving electrode are always maintained in a close positional relationship. Figure 4 P shows a state in which a wire-shaped foreign substance with 400% strength is erected toward the gas insulated conductor by the voltage applied to the gas insulated conductor, and a high electric field is present at the tip of the foreign substance P. Due to the concentration, a partial discharge occurs in the gas in this area. At this time, the partial discharge current flows as an internal force in the gas-insulated conductive part, but at the same time, the potential of the receiving electrode 7, which is floating from the dog's position via the detection impedance, is based on the discharge at the needle end near the electrode. Changes under the influence of sudden changes in the electric field. That is, the receiving electrode 7 acts as an antenna for receiving the frame magnetic waves from the discharge portion. Therefore, the smaller the silence of the receiving electrode is, the easier it will be to cope with the frequency-controlled magnetic waves. In the above-mentioned embodiment, the receiving electrode 7 is made into a rod shape with a small electrode area, so that the detection part C2 can be made small, and if a detection impedance such as a pulse transformer is installed inside the hand hole 9, conductivity can be achieved. Partial discharges caused by electric field levitation of foreign objects can be detected with high accuracy. In addition, by arranging the light-receiving end face of the base 4 at various locations along the length of the electrode, it is possible to simultaneously use the discharge light emitted along with the partial spread, so that it is possible to distinguish between external noise and internal spread. Can do the same with glass counterfeits. Furthermore, if a partial discharge detection means as described in miJ is installed in each airtight container in which gas is separated, the occurrence of partial discharge can be minimized.

According to the present invention, the following effects were obtained as is clear from the explanation given in iJ. In other words, among the causes of the electric breakdown accident in the gas-extinct IL# and the enclosure enclosure, there are
Focusing on conductive foreign matter that is difficult to break and control during manufacturing, we installed a receiving electrode for detecting the tortoise magnet and a bottom detection electrode at the bottom of the sealed container, where conductive foreign matter is easily trapped. By providing a partial discharge detection means made of a light guide for use in the airtight container, and by providing a lead-out part that can take out the output from a hand hole provided at the bottom of the sealed container, the number of parts K tl is provided in the lead-out part.
Partial discharge tests can be performed at any time by connecting a llll meter.
In addition, partial discharge caused by S* foreign matter, which has been difficult to detect in the past, can be detected with almost the same detection sensitivity no matter where it occurs in the axial direction of the closed container.

In addition, by providing a gas-shuttle closure device that is pre-installed with the above-mentioned partial discharge detection means, it is possible to periodically or constantly monitor the number of parts during operation, and to detect abnormalities in sealed electrical appliances at an early stage. insulation accidents can be prevented.

[Brief explanation of the drawing]

1 and 2 are a cross-sectional view and a longitudinal view showing an example of the present invention, FIG. 3 is a structural diagram of a partial discharge means, and FIG. 4 is a partial discharge detection means. It is a mock diagram showing the function of. In the figure, l: airtight container, 2: columnar insulating spacer, 3
: Gas insulating ring trouble part, 4: Metal flange, 5: Gas discharge spacer, 6: Transparent protection member, 7: Receiving electrode, 8: Light guide, 9: Nodhole, 10: Keta bulkhead, 11: Original acid liquid exchange part, 12: Derivation part, 13: 0 ring, Z: detection impedance, P: pressure resistance, 54 items. (B) (B) No. 1 73 T 4th

Claims (1)

[Claims] 1) A cylindrical vMl containing a gas-insulated conductive part; 1. 4ie light guides arranged along the longitudinal direction of the container in the vicinity of the inner peripheral surface of the container and having light-receiving end faces at different positions in the longitudinal direction, and a light guide covering at least the outer peripheral side of the light guide. A transparent surface retaining member attached to a closed container, a perforated plate-shaped receiving pole attached to cover the outer peripheral surface of this member, and a received signal from this electrode and a received signal from the light guide are sealed respectively. An internal discharge detection device for a gas-insulated sealed electrical appliance, characterized in that a lead-out portion for taking out the outside of the container is biased. 2. The inside of a gas-insulated sealed electrical appliance, characterized in that the device according to claim 1, wherein the protective member is formed as a hollow body with closed end faces, and a light guide is housed in the inner hole of the protective member. Discharge detection device. 3) The device according to claim 1, wherein the protective member is a plastic molded article having a refractive index different from that of the light guide in which the light guide is embedded; e Internal discharge detection device for gate closure. 4) In the device according to claim 1, the gas is characterized in that the outer shape of the preservation member and the shape of the receiver 16 are formed into a catfish shape convex toward the inside of the closed container. An internal discharge detection device for a completely sealed device. 5) In the apparatus according to claim 1, is this apparatus a gas-separated storage l;? An internal discharge detection device for a gas insulated Takanjima ware, characterized in that it is provided for each valley finger.