JP4895943B2 - Ground switchgear - Google Patents

Description

  The present invention relates to a gas insulated ground switchgear.

Conventionally, in a power plant, a substation, etc., a ground switch is used for grounding a main circuit at the time of equipment inspection or power supply grounding or as a ground insulation terminal for various measurements. In a conventional earthing switch, for example, grounding or insulation is performed by bringing a stationary contact and a movable contact into and out of contact with each other in a container filled with an insulating medium such as SF ₆ gas (see Patent Document 1). reference).

Japanese Patent Laid-Open No. 6-119852 JP-A-6-335125

  In the ground switch, when the movable contact and the stationary contact are separated from each other, an arc is generated between the two contacts, and the insulation performance is deteriorated. As a method for extinguishing such an arc, for example, a heat puffer method can be adopted. In the thermal puffer system, the insulating gas heated and pressurized by the arc energy is accumulated in the puffer chamber, and the arc is extinguished by blowing a high-pressure insulating gas to the arc in the vicinity of the current zero point. However, the thermal puffer system has excellent arc extinguishing performance when the breaking current is large and the arc energy is large, but when the breaking current is small, the pressure rise in the puffer chamber is not sufficient, so that sufficient arc extinguishing performance is realized. There is a problem that it is difficult.

  In addition, in the conventional gas circuit breaker, which is different from the ground switch, a magnetic drive type gas circuit breaker is known in which the arc is extinguished by rotating the arc by magnetism or the like, even when the interruption current is small. It is used to demonstrate high arc extinguishing performance. For example, in the gas circuit breaker described in Patent Document 2, in the configuration including the fixed contact connected to the main circuit and the movable contact contacting and separating from the fixed contact, the vicinity of the fixed contact, that is, the main contact A permanent magnet is provided in the circuit portion, and the current is interrupted by making the arc behave by the magnetism generated by the permanent magnet. However, in the conventional gas circuit breaker described in Patent Document 2, the location where the permanent magnet is disposed is the main circuit portion, and the permanent magnet is disposed around the location where the permanent magnet is located. Easy to be affected. Therefore, there has been a problem that the magnetism of the permanent magnet is deteriorated due to the influence of arc heat, and the interruption performance is lowered.

  This invention is made | formed in view of the above, Comprising: It aims at providing the earthing switchgear which has the deterioration of the interruption | blocking performance by arc heat, and has the high interruption | blocking performance stably over a long period of time.

  In order to solve the above-described problems and achieve the object, a ground switchgear according to the present invention includes a fixed contact in a tank filled with an insulating gas, and a movable that can be reciprocated with respect to the fixed contact. A grounding switch that performs grounding or separation by contacting and separating the fixed contact and the movable contact, and a permanent magnet on the movable contact side with respect to the fixed contact The arc is extinguished by causing an arc generated between the fixed contact and the movable contact to behave by a magnetic field of the permanent magnet.

  According to the present invention, since the permanent magnet is provided on the movable contact side with respect to the stationary contact, the permanent magnet is disposed away from the arc generation location around the contact point. Since the magnetic deterioration of the magnet is reduced, and hence the deterioration of the interruption performance due to arc heat is reduced, the high interruption performance can be maintained stably over a long period of time.

  Embodiments of a ground switch according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view showing a configuration of a ground switchgear according to Embodiment 1 of the present invention, and is a diagram showing an arrangement configuration in a separated state.

As shown in FIG. 1, in the ground switchgear of the present embodiment, a main circuit tank 1 and a ground switchgear tank 4 having a smaller diameter than the main circuit tank 1 are provided at one end of the main circuit tank 1. The adapter 6 is connected coaxially. The ground switchgear tank 4 is grounded as a tank for the ground switchgear, and the main circuit tank 1 is a tank that accommodates the main circuit part. The main circuit tank 1 and the ground switchgear tank 4 are filled with an insulating gas made of, for example, SF ₆ gas.

  For example, a cylindrical fixed contact (contact) 2 connected to a conductor 3 which is a part of the main circuit section is provided inside the main circuit tank 1. A shield 7 is attached to the conductor 3 so as to cover it.

  A movable contact 5 that can be reciprocally driven in the axial direction by a driving device (not shown) is provided in the ground opening / closing device tank 4, and the movable contact 5 contacts and is separated from the fixed contact 2. That is, the movable contact 5 has a shape that can be inserted into the fixed contact 2, contacts the fixed contact 2 by moving to the fixed contact 2 side, and separates by moving to the opposite side. Further, for example, a cylindrical contact 9 that collects current from the movable contact 5 is connected to the movable side auxiliary conductor 8 connected to the inner peripheral surface of the ground switchgear tank 4. The inner diameter of the contact 9 is slightly larger than the outer diameter of the movable contact 5, and its axis is aligned with the axis of the movable contact 9. The movable contact 5 reciprocates so as to penetrate the cylindrical contact 9 in the axial direction, and the tip of the contact 9 is slidably in contact with the movable contact 5.

  The adapter 6 has a disk shape in which a hole having a size through which the movable contact 5 can penetrate is provided at the center, and the diameter of the hole provided in the adapter 6 is smaller than the inner diameter of the ground switchgear tank 4. That is, the adapter 6 extends in the radial direction toward the axis so that its end in the direction toward the axis is closer to the axis than the inner peripheral surface of the ground switchgear tank 4. A partition wall is formed so as to partially separate 1 and the ground switchgear tank 4. An end surface on the axis line side of the adapter 9 surrounds the outer periphery of the movable contact 5.

  Since the electric field around the movable contact 5 becomes higher due to the current flowing when energized, it is necessary to shield such a high electric field. In the present embodiment, as described above, the adapter 6 is extended on the axis side so as to surround the movable contact 5 in the circumferential direction. Therefore, by forming the adapter 6 from, for example, a metal material, the function as a shield can be achieved. Can be granted.

  An arc-driven permanent magnet 10 is embedded at the tip of the adapter 6 on the axis line side. The shape of the permanent magnet 10 is, for example, a ring shape, and is disposed so as to surround the outer periphery of the movable contact 5. The permanent magnet 10 is installed on the movable contact 5 side with respect to the positional relationship between the movable contact 5 and the fixed contact 2. Alternatively, the permanent magnet 10 is provided not on the main circuit part side but on the ground side, and is disposed so as to be away from the contact point between the movable contact 5 and the fixed contact 2.

  Next, the operation of the present embodiment will be described. The conductor 3 is connected to the fixed contact 2, the movable contact 5, and the contact 9 by driving the movable contact 5 in the direction of the fixed contact 2 and bringing the movable contact 5 and the fixed contact 2 into electrical contact, and is grounded. It becomes a state. In order to shift from the grounded state to the separated or insulated state, the movable contact 5 is driven to the movable side to be separated from the fixed contact 2. At this time, an arc is generated between the movable contact 5 and the fixed contact 2. In the magnetic field generated by the permanent magnet 10, the arc receives a driving force in a direction orthogonal to the current flowing through the arc and the direction of the magnetic field, and behaves such as rotating and stretching according to the direction of the magnetic field. As a result, the arc is cooled and the insulation performance is restored.

  According to the present embodiment, the permanent magnet 10 is embedded in the adapter 6 provided on the movable contact 5 side, so that the permanent magnet 10 is placed on the ground side and away from the arc generation location around the contact. Therefore, the permanent magnet 10 is less susceptible to deterioration due to arc heat. Moreover, since the permanent magnet 10 is embedded in the adapter 6, the influence of heat caused by the arc current and the influence of the electromagnetic field are further reduced. Thus, the magnetic deterioration of the permanent magnet 10 due to the influence of the arc heat is reduced, and there is an effect that high interruption performance can be maintained stably over a long period of time. For example, as in the case of the gas circuit breaker described in Patent Document 2, in the prior art, the permanent magnet is installed not on the ground side but on the main circuit side closer to the arc generation location. It was in a state where it was exposed to a high temperature due to heat, and the permanent magnets were unavoidably deteriorated. In the present embodiment, by selecting the permanent magnet 10 having a high magnetic field strength, the permanent magnet 10 can obtain the same arc driving effect as the permanent magnet 10 is located away from the arc generation location. Can be avoided.

Embodiment 2. FIG.
FIG. 2 is a cross-sectional view showing a configuration of a ground switchgear according to Embodiment 2 of the present invention. In the first embodiment, the adapter 6 that connects the main circuit tank 1 and the ground switchgear tank 4 also has a function as a shield for the movable contact 5, but in this embodiment, the adapter 11 has only a tank connection function. And the shield 13 is separately installed. In the following, in the description of FIG. 2, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 2, the shield 13 branches off from the movable auxiliary conductor 12 connected to the inner surface of the ground switchgear tank 4, and the shield 13 is arranged so that the contact 9 is disposed inside the shield 13. Covers the outer surface of the contact 9. Further, since the movable contact 5 is reciprocated in the axial direction so as to penetrate the inside of the cylindrical contact 9, the shield 13 is provided so as to cover at least a part of the movable contact 5. The shield 13 has a function of shielding a high electric field generated around the movable contact 5.

  An arc-driven permanent magnet 10 is embedded at the tip of the shield 13 on the fixed contact 2 side. The shape of the permanent magnet 10 is, for example, a ring shape, and is disposed so as to surround the outer periphery of the movable contact 5. Moreover, the said front-end | tip part in which the permanent magnet 10 is embed | buried is located in the tank connection part in which the adapter 11 is arrange | positioned about the axial direction, and the permanent magnet 10 of this Embodiment is the permanent magnet of Embodiment 1. It is set up in the same place. Therefore, the installation location of the permanent magnet 10 is on the movable contact 5 side with respect to the positional relationship between the movable contact 5 and the fixed contact 2. Alternatively, the permanent magnet 10 is provided not on the main circuit part side but on the ground side, and is disposed so as to be away from the contact point between the movable contact 5 and the fixed contact 2.

  In the present embodiment, the arrangement of the permanent magnet 10 is the same as that of the first embodiment except that the permanent magnet 10 is embedded in the tip of the shield 13 instead of the adapter 11. Has the same effect as. That is, the permanent magnet 10 is less likely to be deteriorated by arc heat because the permanent magnet 10 is disposed on the ground side and away from the arc generation site around the contact. Therefore, the magnetic deterioration of the permanent magnet 10 due to the influence of the arc heat is reduced, and there is an effect that high interruption performance can be maintained stably over a long period of time.

Embodiment 3 FIG.
FIG. 3 is a cross-sectional view showing a configuration of a ground switchgear according to Embodiment 3 of the present invention. In the first embodiment, the permanent magnet 10 is embedded in the adapter 6. However, in the present embodiment, the permanent magnet 10 is fixed to the surface of the adapter 6 on the fixed contact 2 side and covered with the insulating member 15. ing. In FIG. 3, the same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 3, the adapter 14 has the same shape as the adapter 6 of FIG. 1, and has a tank connection function and an electric field blocking function as a shield, as in the first embodiment. A permanent magnet 10 coated with an insulating member 15 is fixed to the surface of the adapter 14 on the axis side and on the surface of the fixed contact 2. The location of the permanent magnet 10 is almost the same as in the first or second embodiment, and therefore the location of the permanent magnet 10 is movable with respect to the positional relationship between the movable contact 5 and the fixed contact 2. It is the contact 5 side. Alternatively, the permanent magnet 10 is provided not on the main circuit part side but on the ground side, and is disposed so as to be away from the contact point between the movable contact 5 and the fixed contact 2.

  According to the present embodiment, as in the first and second embodiments, the magnetic deterioration of the permanent magnet 10 due to the influence of the arc heat is reduced, and the high interruption performance can be maintained stably over a long period of time. Play. Further, since the permanent magnet 10 is fixed to the surface of the adapter 14 without being embedded in the adapter 6 of the first embodiment or the shield 13 of the second embodiment, it is easy to install the magnet 10. Become.

  As described above, the ground switchgear according to the present invention can be suitably used for a gas-insulated ground switchgear used in a power plant, a substation, or the like.

It is sectional drawing which shows the structure of Embodiment 1 of the earthing | grounding switchgear which concerns on this invention. It is sectional drawing which shows the structure of Embodiment 2 of the earthing | grounding switchgear which concerns on this invention. It is sectional drawing which shows the structure of Embodiment 3 of the earthing | grounding switchgear concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main circuit tank 2 Fixed contact 3 Conductor 4 Grounding switchgear tank 5 Movable contact 6, 11, 14 Adapter 7, 13 Shield 8, 12 Movable side auxiliary conductor 9 Contact 10 Permanent magnet 11 Adapter 15 Insulation member

Claims (5)

In a tank filled with an insulating gas, a fixed contact and a movable contact that can be driven back and forth with respect to the fixed contact are provided, and the fixed contact and the movable contact are brought into and out of contact with each other. In a grounding switchgear that performs grounding or separation,
A permanent magnet is provided on the movable contact side with respect to the fixed contact,
An earthing switchgear comprising: extinguishing the arc by causing an arc generated between the fixed contact and the movable contact to behave by a magnetic field of the permanent magnet. The tank
A first tank in which a contact point between the fixed contact and the movable contact is located and a main circuit unit connected to the fixed contact and the fixed contact is accommodated;
A second tank on the ground side in which the movable contact is accommodated when the opening operation is completed;
The first tank and the second tank are coaxially joined, and the end in the direction toward the axis is extended so as to be closer to the axis than the inner peripheral surface of the second tank. And an adapter provided with a hole through which the movable contact can pass,
With
The grounding switchgear according to claim 1, wherein the permanent magnet is provided at the end of the adapter.   The grounding switchgear according to claim 2, wherein the permanent magnet is embedded in the adapter.   The grounding switchgear according to claim 2, wherein the permanent magnet is provided on the adapter surface on the fixed contact side and is covered with an insulating member. An electric field shield provided to cover at least a part of the outer periphery of the movable contact;
The grounding switchgear according to claim 1, wherein the permanent magnet is provided at a tip of the electric field shield on the fixed contact side.

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