JP2014199769A - Gas insulation breaker and capacitor unit used for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas insulation breaker capable of preventing mechanical destruction by releasing an impact force applied to respective capacitor elements of a capacitor unit.SOLUTION: The gas insulation breaker, opening and closing an electric run by switching energization or cut-off, includes: a pair of contacts comprised of a fixed side cut-off contact 7 and a movable side cut-off contact 8 capable of energization and cut-off for switching the energization or the cut-off by a contact or separation operation, and a capacitor laminate 1 formed by serially connecting a plurality of capacitors 1-1 to 1-n which are connected in parallel to the contacts and each of which has a dielectric substance. The dielectric substance is a piezoelectric substance and between the capacitors, a spring structure 9 is disposed.

Description

  Embodiments described herein relate generally to a gas insulated circuit breaker including a capacitor unit provided at a breaker contact of a breaker used in a substation or the like in a power system, and the capacitor unit.

  With recent technological innovations regarding high-voltage insulation, there is an increasing demand for downsizing gas-insulated high-voltage equipment year by year. On the other hand, even if the gas-insulated high-voltage device is downsized, it is necessary to ensure current interruption performance.

  When current interruption is performed by a gas insulated circuit breaker, which is one of gas-insulated high-voltage equipment, the system is complex, so the transient recovery voltage generated between the contact poles after the interruption has a very complicated waveform. Is customary. For this reason, the gas insulation circuit breaker is obligated to interrupt the circuit under various conditions. Conventionally, in order to achieve such an interrupting duty, the arc is extinguished by blowing a compressed arc extinguishing gas onto the arc generated between the contacts of the interrupting contact, and the current is interrupted.

  Further, in order for the gas insulated switch to succeed in breaking, it is necessary for the insulation between the contact electrodes of the breaking contact to withstand the transient recovery voltage that appears after breaking is established near the current zero point. Therefore, the interruption performance is improved by inserting a capacitor unit in parallel with the interruption contact and dulling the rise time of the transient recovery voltage that appears after interruption. Such a capacitor unit has a capacitor laminate in which a plurality of capacitor elements are connected in series.

  That is, by providing a capacitor unit in parallel with the breaking contact, the rate of increase of the re-starting voltage after breaking at the breaking contact is reduced, and the voltage sharing of the voltage applied to the breaking contact of the breaker having two or more breaking contacts is provided. The rate is equalized to make blocking easier.

Japanese Patent Laid-Open No. 06-338436

  By the way, the gas insulated circuit breaker needs to be able to withstand a certain overvoltage even if a lightning voltage enters the device due to a lightning strike. Therefore, before shipping the gas insulated circuit breaker, there is an obligation to confirm that the insulation reliability of the equipment is maintained by applying the lightning overvoltage defined in the standard multiple times.

  In the confirmation test, when the lightning overvoltage is applied, the lightning overvoltage is applied to each of the individual capacitor elements constituting the capacitor unit on average. When ceramics is used as the dielectric material of a capacitor element, ceramics have a piezoelectric effect that causes the shape of the capacitor itself to deform when an electric current is applied. Therefore, when a lightning overvoltage is applied, Stretching impact force is generated in the stacking direction. Since this expansion / contraction impact force is generated in the entire capacitor laminate, a strong expansion / contraction impact force is generated in the capacitor element lamination direction. Since this strong expansion and contraction impact force is directly applied to each capacitor element, the capacitor element cannot withstand the strong force, causing the capacitor element to crack or the like, and may be mechanically destroyed.

  The gas insulated circuit breaker according to the present embodiment is made in order to solve the above-described problems. The gas insulating circuit breaker relaxes the impact force applied to each capacitor element of the capacitor unit and prevents mechanical destruction. An object is to provide an insulated circuit breaker. It is also an object to provide such a capacitor unit.

  In order to achieve the above object, the gas circuit breaker according to the present embodiment is a gas insulated circuit breaker that opens and closes an electric circuit by switching between energization and interruption, and is freely connectable and separable to switch between energization and interruption by contact or separation. And a capacitor laminate formed by connecting a plurality of capacitors each having a dielectric connected in series, and the dielectric is a piezoelectric body, and an elastic body between the capacitors. It is characterized by arranging.

It is sectional drawing for demonstrating the structure of the gas insulated circuit breaker which concerns on 1st Embodiment. It is AA sectional drawing of FIG. It is an enlarged view between capacitor elements concerning a 1st embodiment, (a) shows the connection state between capacitor elements, and (b) shows the decomposition state between capacitor elements. It is sectional drawing for demonstrating the structure of the gas insulated circuit breaker which concerns on 2nd Embodiment. It is an enlarged view between the capacitor | condenser elements which concern on 2nd Embodiment, (a) shows the case where a rubber elastic body is the maximum diameter, (b) shows the case where a rubber elastic body is the minimum diameter.

[First Embodiment]
(Constitution)
Below, the structure of the gas insulated circuit breaker of this embodiment is demonstrated, referring FIGS. 1-3. FIG. 1 is a cross-sectional view showing the configuration of the gas insulated circuit breaker of the present embodiment, showing one side from the central axis of the gas insulated circuit breaker.

The gas insulated circuit breaker of the present embodiment includes a sealed container (not shown), a fixed-side cutoff contact 7 and a movable-side cutoff contact 8. The sealed container is filled with an arc extinguishing gas. The arc extinguishing gas is a gas excellent in arc extinguishing performance and insulation performance, and examples thereof include sulfur hexafluoride gas (SF ₆ gas), air, carbon dioxide, oxygen, nitrogen, or a mixed gas thereof.

  The fixed-side cutoff contact 7 and the movable-side cutoff contact 8 are accommodated in a sealed container and are arranged to face each other. The fixed-side cutoff contact 7 is fixed in a sealed container, and the movable-side cutoff contact 8 is movable with respect to the fixed-side cutoff contact 7. To conduct or cut off the current.

  As shown in FIG. 1, the gas insulated circuit breaker of this embodiment has a capacitor unit 5. The capacitor unit 5 includes an insulating cylinder 3, a capacitor laminate 1, a spring structure 9, a connection electrode 2, and a shield electrode 4.

  The insulating cylinder 3 is disposed in the hermetic container so as to extend in parallel with the two interrupting contacts 7 and 8 disposed so as to face each other, and is connected in parallel to the both interrupting contacts 7 and 8. FIG. 2 is a cross-sectional view taken along line AA of FIG. As shown in FIG. 2, a plurality (six) of the insulating cylinders 3 are arranged in the circumferential direction around the central axis. The insulating cylinder 3 in FIG. 1 is one of them.

  The insulating cylinder 3 is a cylinder made of an insulator, and both ends thereof are open and the inside is hollow. The capacitor laminate 1 is accommodated in the hollow portion.

  The capacitor multilayer body 1 is configured by connecting a plurality of capacitor elements 1-1 to 1-n in series. Each capacitor element 1-1 to 1-n has a cylindrical shape, and as shown in FIG. 3, electrodes 1c and 1d are joined to both ends of the dielectric 1a, and the periphery of the dielectric 1a is molded with an insulator 1b. Do it. The dielectric 1a is covered with the insulator 1b and the electrodes 1c and 1d, but at least a part of the electrodes 1c and 1d is not covered with the insulator 1b and is exposed.

  The dielectric 1a is made of a high dielectric material such as ceramics. That is, the dielectric 1a is a piezoelectric having a piezoelectric effect, and its shape is deformed when a current flows through the dielectric 1a. The insulator 1b is an insulator made of an insulating material such as an epoxy resin. The electrodes 1c and 1d are conductors. By adjusting the number of capacitor elements as required, the capacitor unit 5 has the required capacitance and withstand voltage performance.

  In the capacitor multilayer body 1 of the present embodiment, the spring structure 9 is disposed between the capacitor elements. The spring structure 9 is an elastic body having an elastic force. The spring structure 9 has a spring structure and can be composed of a conductive material such as various metal materials.

  FIG. 3 shows an enlarged view between the capacitor elements in the capacitor laminate 1, FIG. 3A shows a connection state between the capacitor elements, and FIG. 3B shows an exploded state between the capacitor elements. As shown in FIG. 3 (b), grooves 10 are provided in the electrodes 1 c and 1 d of the adjacent capacitor elements, so that the spring structure 9 can be fitted into the grooves 10. That is, the capacitor elements 1-1 to 1-n and the spring structures 9 are alternately accommodated in the insulating cylinder 3, and the spring structures 9 are adjacent to each other as shown in FIG. The capacitor elements are accommodated and positioned in the grooves 10 of the two electrodes 1c and 1d facing each other.

  As shown in FIG. 1, the connection electrodes 2 are connected to the capacitor elements 1-1 and 1-n located at both ends in the insulating cylinder 3 so as to sandwich the capacitor laminate 1 in the insulating cylinder 3. The capacitor laminate 1 is connected to the shield electrode 4 via the connection electrode 2. An outer shield 6 is provided on the outer periphery of the shield electrode 4. The outer shield 6 protrudes in the central axis direction so as to cover the connection electrode 2. The external shield 6 reduces the concentration of an electric field locally at a so-called triple junction between the outer surface of the connection electrode 2 and the inner surface of the insulating cylinder 3 and a high electric field.

(Action / Effect)
In an insulation reliability test of equipment before shipment of the gas insulated circuit breaker, that is, a test in which a lightning overvoltage defined by a standard is applied a plurality of times, a current flows through the dielectric 1a of the capacitor elements 1-1 to 1-n. Since the dielectric body 1a is a piezoelectric body having a piezoelectric effect, it expands and contracts in the direction of the central axis when an electric current flows, and an expansion / contraction impact force is generated.

  In the present embodiment, since the spring structure 9 having elastic force is disposed between the capacitor elements, the expansion / contraction impact force generated in each capacitor element is absorbed by the adjacent spring structure 9. The expansion and contraction impact force does not reach other capacitor elements. As a result, a strong expansion / contraction impact force is not generated, and thus it is possible to prevent the capacitor element from being mechanically destroyed due to cracks or the like without being able to withstand the strong expansion / contraction impact force.

  Since the grooves 10 for disposing the spring structure 9 are provided in the electrodes 1c and 1d adjacent to each other of the capacitor elements 1-1 to 1-n, the groove 10 has a depth so that the spring structure 9 is displaced. Can be prevented. In other words, when the capacitor unit 5 is configured by alternately inserting the capacitor elements and the spring structure 9 into the insulating cylinder 3, the spring structure 9 can be surely arranged at a predetermined position by a simple operation. As a result, it is possible to prevent the function of absorbing, i.e., the absorption effect of the stretching impact force from being impaired.

  Further, since the grooves 10 are provided in the electrodes 1c and 1d, the length in the stacking direction of the capacitor elements 1-1 to 1-n can be shortened by the depth of the groove 10, thereby saving space. it can. As a result, the gas insulated circuit breaker can be further downsized. Furthermore, as compared with the case where the groove 10 is not provided, a larger number of capacitor elements can be arranged to save space, so that the withstand voltage performance can be enhanced even in the same space.

  Since the spring structure 9 is made of a conductive material, the spring structure 9 serves as a connecting portion between the capacitor elements, so that the electrodes 1c and 1d of the adjacent capacitor elements are electrically connected. There is no need to arrange a new member, and the number of parts can be reduced.

  As described above, according to the present embodiment, it is possible to obtain a gas insulated circuit breaker having good insulation reliability, a simple configuration, and an inexpensive capacitor unit.

[Second Embodiment]
(Constitution)
A second embodiment will be described with reference to FIGS. The basic configuration of the second embodiment is the same as that of the first embodiment. Only the differences from the first embodiment will be described, and the same parts as those in the first embodiment will be denoted by the same reference numerals and detailed description thereof will be omitted.

  FIG. 4 is a cross-sectional view showing the configuration of the gas insulated circuit breaker according to the second embodiment, and shows one side from the central axis of the gas insulated circuit breaker. The gas insulated circuit breaker according to the present embodiment is characterized in that, in the capacitor unit 5, the spring structure 9 according to the first embodiment is used as a rubber elastic body 11, and the electrodes 1e and 1f of the capacitor elements 1-1 to 1-n have grooves. It differs in that it is not provided.

  The rubber elastic body 11 is an elastic body made of rubber having elasticity. As shown in FIG. 4, the rubber elastic body 11 is disposed between the capacitor elements. As shown in FIGS. 5 (a) and 5 (b), the outer diameter of the rubber elastic body 11 can be configured to have a length within a range from the half of the outermost diameter of the capacitor element to the same diameter. 5A shows a case where the rubber elastic body 11a has the same diameter as the outermost diameter of the capacitor element, and FIG. 5B shows a case where the rubber elastic body 11b has a diameter half the outermost diameter of the capacitor element. Is shown. The rubber elastic body 11 can be made of a conductive rubber material.

(Action / Effect)
The gas circuit breaker according to the present embodiment has the same operational effects as the first embodiment. In this embodiment, the elastic elastic body 11 is disposed instead of the spring structure 9 between the capacitor elements, so that the elastic shock generated in each of the capacitor elements 1-1 to 1-n. The force is absorbed by the adjacent rubber elastic body 11, and the expansion / contraction impact force does not reach other capacitor elements. Therefore, since a strong expansion / contraction impact force is not generated, it is possible to prevent the capacitor elements 1-1 to 1-n from being mechanically destroyed without being able to withstand the strong expansion / contraction impact force.

  Further, the outer diameter of the rubber elastic body 11 was set to a length within a range from the half of the outermost diameter of the capacitor element to the same diameter. As a result, the radial displacement of the rubber elastic body 11 that occurs when the capacitor unit and the rubber elastic body 11 are alternately inserted into the insulating cylinder 3 to form the capacitor unit 5 is at most shown in FIG. Thus, the position reaches half the outermost diameter of the capacitor element, and the possibility of impairing the function as a rubber, that is, the absorbing effect of the stretching impact force can be reduced. Further, by reducing the outer diameter of the rubber elastic body 11 within the above range, it is possible to reduce the manufacturing cost of the gas insulated circuit breaker while ensuring the above-described absorption action.

  By setting the outer diameter of the rubber elastic body 11 within the above range, the above-described absorption action is ensured even if a radial position shift occurs, so that the positioning is performed on the electrodes 1e and 1f of the capacitor elements 1-1 to 1-n. Therefore, it becomes unnecessary to provide a groove for the gas insulation, and as a result, the manufacture of the gas insulated circuit breaker is facilitated.

  In the present embodiment, the elastic body disposed between the capacitor elements is the rubber elastic body 11, so that even if it is thin in the axial direction, it is possible to obtain the effect of absorbing the expansion / contraction impact force and to save space in the axial direction. Can do.

  Since the rubber elastic body 11 is made of a conductive material, the rubber elastic body 11 serves as a connecting portion between the capacitor elements, so that the electrodes 1e and 1f of the adjacent capacitor elements are electrically connected. There is no need to arrange a new member, and the number of parts can be reduced.

  As described above, according to the present embodiment, it is possible to obtain a gas insulated circuit breaker having good insulation reliability, a simple configuration, and an inexpensive capacitor unit.

[Other Embodiments]
In the present specification, a plurality of embodiments according to the present invention have been described. However, these embodiments are presented as examples and are not intended to limit the scope of the invention. Specifically, a combination of all or any of the first and second embodiments is also included. The above embodiments can be implemented in other various forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the invention described in the claims and equivalents thereof as well as included in the scope and gist of the invention.

  For example, in the first and second embodiments, the insulating cylinder 3 is provided in a plurality of circumferential shapes around the breaking contacts 7 and 8, but the insulating cylinder has a double cylinder structure of an inner cylinder and an outer cylinder. You may arrange | position so that the said inner cylinder may surround the interruption | blocking contacts 7 and 8. FIG. In this case, the capacitor laminate is accommodated between the inner cylinder and the outer cylinder.

  In the first and second embodiments, the fixed-side cutoff contact 7 is fixed and only the movable-side cutoff contact 8 is moved in the axial direction. However, the movable-side cutoff contact 8 is relative to the fixed-side cutoff contact 7. Alternatively, the fixed-side breaking contact 7 may be moved in the axial direction so as to be moved, so that a so-called dual motion mechanism for improving the relative opening speed may be used.

  In the second embodiment, the electrodes 1e and 1f of the capacitor elements 1-1 to 1-n are not provided with grooves as in the first embodiment, but the rubber elastic body 11 is provided on these electrodes 1e and 1f. A groove to be accommodated may be provided. That is, in the capacitor elements adjacent to each other, a groove for accommodating the rubber elastic body 11 may be provided in the electrodes 1e and 1f facing each other, and the rubber elastic body 11 may be fitted in the groove.

DESCRIPTION OF SYMBOLS 1 Capacitor laminated body 1-1 to 1-n Capacitor element 1a Dielectric 1b Insulator 1c to 1f Electrode 2 Connection electrode 3 Insulating cylinder 4 Shield electrode 5 Capacitor unit 6 External shield 7 Fixed side cutoff contact 8 Movable side cutoff contact 9 Spring Structure 10 Groove 11 Rubber elastic body 11a Maximum diameter rubber elastic body 11b Minimum diameter rubber elastic body

Claims (8)

A gas-insulated circuit breaker that switches between energization and interruption to open and close the electric circuit,
A pair of contactable and separable contacts that switch between energization or blocking by contact or separation; and
A capacitor laminate formed by connecting a plurality of capacitors having dielectrics connected in parallel with the contacts; and
The dielectric is a piezoelectric body,
A gas insulated circuit breaker characterized in that an elastic body is disposed between the capacitors.   The gas insulated circuit breaker according to claim 1, wherein the elastic body is a spring structure.   The gas insulated circuit breaker according to claim 1, wherein the elastic body is a rubber elastic body. The capacitor has two electrodes sandwiching the piezoelectric body therebetween,
The gas insulated circuit breaker according to claim 2, wherein in the capacitors adjacent to each other, a groove for accommodating the spring structure is formed in the electrodes facing each other. Further comprising an insulating cylinder in which the capacitor laminate is accommodated,
4. The gas insulated circuit breaker according to claim 3, wherein an outer diameter of the rubber elastic body is a length within a range from a half of an outer diameter of the capacitor to the same diameter. 5.   The gas insulated circuit breaker according to claim 2 or 4, wherein the spring structure is made of a conductive material.   6. The gas insulated circuit breaker according to claim 3, wherein the rubber elastic body is made of a conductive material. A capacitor laminate formed by connecting a plurality of capacitors having a dielectric in series;
An insulating cylinder that accommodates the capacitor laminate therein;
Electrodes connected to both ends of the capacitor laminate,
The dielectric is a piezoelectric body,
A capacitor unit, wherein an elastic body is disposed between the capacitors.

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