JP2011113666A - Mold vacuum valve and method for testing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the operation time period by reducing the number of times of a partial discharge test applied to a mold vacuum valve. <P>SOLUTION: The mold vacuum valve includes: a vacuum insulation container 1; a pair of attachable/detachable contacts 5 and 6 stored in the vacuum insulation container 1; a fixed-side current-carrying shaft 4 connected to one contact 5; a movable-side current-carrying shaft 7 connected to the other contact 6; an insulating layer 10 provided on an outer periphery of the vacuum insulation container 1; and a ground layer 11 provided on an outer periphery of the insulating layer 10. In the movable-side current-carrying shaft 7, an open-circuit testing position 13 is provided for indicating that the status between the contacts 5 and 6 is open-circuit at a predetermined gap. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a mold vacuum valve in which an outer periphery of a vacuum valve is molded with an insulating material such as an epoxy resin to form an insulating layer, and a test method thereof.

  Conventionally, vacuum valves used in the atmosphere have a lower external dielectric strength than in an internal vacuum, so an insulating layer is formed by molding an insulating material on the outer periphery of a vacuum insulating container to reinforce external insulation. It has been broken. And in order to confirm the soundness, such as the inside of an insulating layer and an adhesion interface with a vacuum insulating container, an electrical test such as a partial discharge test is performed after molding (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2005-41063 (pages 3 to 4, FIG. 1)

  The above-described conventional mold vacuum valve has the following problems. The mold vacuum valve has a use condition in which the contact is closed, the contact is open, the fixed side is charged, and the movable side is charged. For this reason, partial discharge tests have to be carried out under these three conditions, respectively, and the number of tests has been increased, resulting in a long working time. In the partial discharge test, for example, it is necessary to remove a noise generation source such as temporarily stopping the crane work, which affects the operation of surrounding equipment.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a mold vacuum valve that can reduce the number of partial discharge tests and shorten the working time, and a test method therefor.

  In order to achieve the above object, a mold vacuum valve according to the present invention includes a vacuum insulating container, a pair of contactable and separable contacts housed in the vacuum insulating container, and a fixed-side energization connected to one of the contacts. A movable side energizing shaft connected to the other end of the contact; an insulating layer provided on an outer periphery of the vacuum insulating container; and a grounding layer provided on an outer periphery of the insulating layer. The shaft is provided with an open circuit test position indicating that the contact is opened to a predetermined gap.

  According to the present invention, since the mold vacuum valve is opened and the test voltage is simultaneously applied to the fixed side and the movable side, the contact is closed, the contact is open, the fixed side is charged, and the movable side is movable. The three conditions of the charged state on the side can be performed by one partial discharge test, and the working time can be shortened.

Sectional drawing explaining the testing method of the mold vacuum valve which concerns on Example 1 of this invention. The figure explaining the test method of the mold vacuum valve which concerns on Example 2 of this invention. The figure explaining the test method of the mold vacuum valve which concerns on Example 3 of this invention.

  A test voltage is simultaneously applied to the fixed side and the movable side while maintaining the open circuit state, and the electric field stress applied in the insulating layer is approximated to the actual use state. Embodiments of the present invention will be described below with reference to the drawings.

  First, a mold vacuum valve according to Example 1 of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view illustrating a mold vacuum valve test method according to Embodiment 1 of the present invention.

  First, the configuration of the mold vacuum valve will be described. As shown in FIG. 1, a fixed-side sealing fitting 2 and a movable-side sealing fitting 3 are sealed at both end openings of the cylindrical vacuum insulating container 1. A fixed-side energizing shaft 4 is fixed through the fixed-side sealing metal fitting 2, and a fixed-side contact 5 is fixed to the end. A movable contact 6 is fixed to an end of the movable energizing shaft 7 that movably penetrates the movable sealing fitting 3 so as to face the fixed contact 5.

  Between the middle part of the movable side energizing shaft 7 and the movable side sealing metal fitting 3, both ends of the expandable bellows 8 are respectively sealed, thereby maintaining the vacuum in the vacuum insulating container 1 and pivoting the movable side energizing shaft 7. It can be moved in the direction. Around the contacts 5 and 6, there is provided an arc shield 9 fixed to the intermediate portion of the inner surface of the vacuum insulating container 1.

  An insulating layer 10 formed by molding an insulating material such as an epoxy resin is provided on the outer periphery of the vacuum valve. A ground layer 11 formed by applying a conductive paint is provided on the outer periphery of the insulating layer 10. At both ends in the axial direction of the insulating layer 10, tapered interface connecting portions 10a and 10b for connecting to other molding devices are formed, and the ends of the current-carrying shafts 4 and 7 are exposed at the shaft center.

  Next, the test method will be described. First, since the movable-side energizing shaft 7 moves in the closing direction by the self-closing force of the vacuum valve, the annular open-circuit holding member 12 that locks the movement of the movable-side energizing shaft 7 at the end of the movable interface connecting portion 10b is provided. Provide and open circuit. By pulling out the screw portion 13 provided in the intermediate portion of the movable side energizing shaft 7 to the end of the interface connecting portion 10b and tightening the open circuit holding member 12, the contact points 5 and 6 can be held in an open circuit state. Here, since the screw part 13 becomes a position which shows having opened the contacts 5 and 6 to the predetermined gap of an actual use state, this is called an open circuit test position.

  Next, the ground layer 11 is grounded, and the same test voltage HV 1 is applied to the fixed-side energizing shaft 4 and the movable-side energizing shaft 7. The test voltage is set to be equal to or higher than the rated voltage of the mold vacuum bulb, and the partial discharge characteristics are measured with a measuring device (not shown). The withstand voltage test can be performed in the same manner.

  Thereby, even in the open circuit state, a test voltage can be applied to the fixed side and the movable side, and a partial discharge test corresponding to the closed circuit state can be performed. Strictly speaking, the electric field stress in the vicinity of the contacts 5 and 6 is different from the closed circuit state, but the gap length between the contacts 5 and 6 is several mm, and the electric field stress applied to the insulating layer 10 is not significantly different. There is no problem in use.

  Further, electric field stress in the open circuit state can be applied to the insulating layer 10 on the fixed side and the movable side, respectively. The electric field stress in the insulating layer 10 is almost the same as the conventional electric field stress in which, for example, the fixed side is applied and the movable side is grounded.

  Although electric field stress cannot be applied between the contacts 5 and 6, verification of partial discharge between the electrodes can be made unnecessary by using a vacuum bulb having a predetermined dielectric strength. When a defect such as a vacuum failure occurs with the mold, it can be sufficiently verified by the above-described method. The test transformer is the same as the conventional one, and it is only necessary to connect the application line in parallel to the fixed side and the movable side, and no additional equipment is required.

  According to the mold vacuum valve of Example 1 above, the contact points 5 and 6 are held open, and the partial discharge test is performed by simultaneously applying the test voltage HV1 to the fixed-side conductive shaft 4 and the movable-side conductive shaft 7. Therefore, there are three conditions: a condition for closing the contacts 5 and 6, a condition for applying the contacts 5 and 6 to the open-side energizing shaft 4, and a condition for applying the moving-side energizing shaft 7. It can be performed by one partial discharge test, and the working time can be shortened.

  Next, a mold vacuum valve according to Example 2 of the present invention will be described with reference to FIG. FIG. 2 is a view for explaining a mold vacuum valve test method according to Embodiment 2 of the present invention. The difference between the second embodiment and the first embodiment is the phase of the applied voltage. Since the configuration of the mold vacuum valve is the same as that of the first embodiment, the description thereof is omitted.

  As shown in FIG. 2, using the three-phase transformer 14, the first phase test voltage HV2 is fixed, and the second phase test voltage HV3 whose voltage phase is shifted by 120 degrees from the first phase is simultaneously moved to the movable side. To be applied. The third phase opens.

  According to the mold vacuum valve of the second embodiment, in addition to the same effects as those of the first embodiment, it is possible to perform verification between the electrodes of the vacuum valve used in the power supply system of different power source butt.

  Next, a mold vacuum valve according to Example 3 of the present invention will be described with reference to FIG. FIG. 3 is a view for explaining a mold vacuum valve testing method according to Embodiment 3 of the present invention. The third embodiment differs from the first embodiment in the phase of the applied voltage. Since the configuration of the mold vacuum valve is the same as that of the first embodiment, the description thereof is omitted.

  As shown in FIG. 3, two single-phase transformers 15 are used, their voltage phases are shifted by 180 degrees, and one test voltage HV4 is applied simultaneously to the fixed side and the other test voltage HV5 to the movable side. is there.

  According to the mold vacuum valve of the third embodiment, in addition to the same effects as those of the first embodiment, it is possible to more strictly verify the gap between the vacuum valves.

DESCRIPTION OF SYMBOLS 1 Vacuum insulating container 2 Fixed side sealing metal fitting 3 Movable side sealing metal fitting 4 Fixed side energizing shaft 5 Fixed side contact 6 Movable side contact 7 Movable side energizing shaft 8 Bellows 9 Arc shield 10 Insulating layer 10a, 10b Interface connection part 11 Contact Formation 12 Opening retaining member 13 Screw portion 14 Three-phase transformer 15 Single-phase transformer

Claims (5)

A vacuum insulation container;
A pair of detachable contacts housed in the vacuum insulating container;
A stationary energizing shaft connected to one of the contacts;
A movable energizing shaft connected to the other of the contacts;
An insulating layer provided on the outer periphery of the vacuum insulating container;
A grounding layer provided on the outer periphery of the insulating layer,
A mold vacuum valve characterized in that an open circuit test position indicating that a gap between the contacts is opened in a predetermined gap is provided on the movable side energizing shaft. A vacuum valve having a pair of detachable contacts;
An insulating layer formed by molding an insulating material on the outer periphery of the vacuum valve;
A test method for a mold vacuum valve comprising a grounding layer provided on the outer periphery of the insulating layer,
Opening a predetermined gap between the pair of contacts;
After grounding the ground layer,
A test method for a mold vacuum valve, wherein a voltage is simultaneously applied to each of the contacts to perform an electrical test.   3. The mold vacuum valve testing method according to claim 2, wherein the voltages applied to the respective contacts have the same phase.   The test method for a mold vacuum valve according to claim 2, wherein the voltages applied to the respective contacts are out of phase by 120 degrees.   The test method for a mold vacuum valve according to claim 2, wherein the voltage applied to each contact is 180 degrees out of phase.

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