JP3277499B2 - Disconnector - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disconnecting switch, and more particularly to a disconnecting switch for supplying a large current to a power generating main circuit of a power plant.

[0002]

2. Description of the Related Art FIG. 7 is a front view showing a partial cross section and an external structure of a conventional disconnector of this type, FIG. 8 is a plan view of FIG.
FIG. 9 is a sectional view taken along the line IX-IX of the jacket in FIG. In the drawing, reference numeral 1 denotes a cylindrical fixed finger contact attached to a movable side conductor 2 forming one side of an electric circuit, and 3 denotes a cylindrical fixed contact attached to a fixed side conductor 4 forming the other side of the electric path. It is arranged so as to face the finger contact 1 at a distance. Reference numeral 5 denotes a cylindrical movable finger contact which is provided so as to operate inside the fixed finger contact 1 in the axial direction and electrically contacts and separates the fixed finger contact 1 and the fixed contact 3, and 6 operates the movable finger contact 5. The feeding mechanism is built in the movable-side conductor 2. Reference numeral 7 denotes an operating device for generating an operating force for operating the movable finger contact 5, and 8 denotes an insulating rod for transmitting the operating force generated by the operating device 7 to the feeding mechanism 6, and these 1 to 8 form a disconnecting portion. . Reference numeral 9 denotes a jacket, which is formed of a body 10 having a substantially concentric cylindrical shape covering each of the contacts 1, 3, and 5 and having an opening 10a for inspection, and an inspection lid 11 which closes the opening 10a and is detachable from the body 10. Have been. Reference numeral 12 denotes a fixture for holding down the inspection lid 11 and attaching the inspection lid 11, which is made of a metal material. 1
3 is a seat welded to the edge of the body of the opening 10a, 14 is a bolt for fixing the fixture 12 to the seat 13, 15 is a packing for increasing airtightness between the body 10 and the inspection lid 11, and 16 is a fixture 12
A stopper 17 for preventing the pressing of the conductors 2 is an insulating support for supporting the conductors 2 and 4 from the jacket 9. FIG. 10 shows an example of a single-line diagram of a power plant to which the disconnector is applied.
18 is a generator, 19 is a phase separation bus, 20 is a circuit breaker, 21
Is a disconnector and 22 is a main transformer.

Next, the operation will be described. The power generated by the operating device 7 operates the movable finger contact 5 attached to the feeding mechanism 6 in the axial direction via the insulating rod 8 to open and close the electric circuit. When the movable finger contact 5 is closed and an electric circuit is formed, the current from the phase separation bus 19b flows through the movable side conductor 2 to the fixed finger contact 1 to the movable finger contact 5 to the fixed contact 3 to the fixed side conductor 4, and the connected phase It flows with the separation bus 19c. on the other hand,
Similar to the phase-separated bus, a current that cancels magnetic flux due to a current flowing in the conductor is induced in the jacket 9. The jacket current flows in the axial direction and has almost the same magnitude as that of the conductor current, with a phase slightly delayed by 180 °. The body 10 of the jacket 9 is made of an aluminum material having high conductivity in order to pass a jacket current. Normally, the jacket current A ₁ is
In the case of the jacket 9, the current density becomes high near the opening 10a of the body 10 as shown in the model of the jacket current in FIG. Further, the eddy current A ₂ under the influence of the enveloping current A ₁ is also induced in the inspection lid 11. Particularly in a portion where the current density of the jacket current A ₁ is high, the eddy current A ₂
Are concentrated on the circumferential end of the inspection lid 11.

Further, when the opening 10a is closed by the inspection lid 11, when the attachment 12 is attached to the inspection lid 11, the fitting 12 covers the surface of the inspection lid 11 at the tip. Inspection cover 1 after the part to be pressed against 11a
1, the body 10 as shown in FIG.
Seat 13-Fixture 12-Inspection lid 11-Fixture 12-Seat 13
An electric circuit such as the body 10 is formed, and the jacket current A ₁
May shunt and current may flow through the above route. The press-contact portion of the coating film 11 with the inner stopper 16 has a large contact surface, so that it is difficult to peel off. The inspection lid 11 corresponds to the opening 10a which is large enough to inspect and care for the contacts inside the disconnector, and is made of a lightweight aluminum plate having a thickness of about 4 mm in consideration of workability. Material is used.

[0005]

Since conventional breaker of this type [0008] is constructed as described above, recent single machine capacity of the generator is increased, the envelope current A ₁ becomes large, access covers with it 11 eddy current a ₂ is increased, the temperature rise by induction heating, and temperature rise is superimposed due to local heat generation of the inspection lid 11 due to the diversion of the enveloping current a ₁ flowing through the fixture 12 through the inspection lid 11, There have been cases where the temperature rise in other jacket parts is significantly higher. For this reason, the allowable current value of the disconnector is restricted, and in order to improve the current capacity of the disconnector, it is necessary to increase the size of the entire disconnector and to easily respond to recent demands for downsizing the switch. There was a problem that it could not be done.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an abnormal heat generation of an inspection cover due to a jacket current can be suppressed, and a disconnector which can be downsized in the same rated current range can be obtained. The purpose is to:

[0007]

Means for Solving the Problems Claim 1 according to the present invention.
The disconnecting switch is formed by a pair of cylindrical contacts provided at the end of the conductor and spaced apart from each other and a movable contact interposed between the contacts and operating in the opposite direction to open and close the electric circuit by contacting and separating with the contact. A disconnecting portion, a trunk portion that covers the disconnecting portion in a substantially concentric cylindrical shape and has an opening for inspection, an inspection lid for closing the opening of the trunk portion, and one end side fixed to the trunk portion near the opening in this state. And a cover formed by a fitting which is attached by pressing the surface of the inspection lid at the other end. The inspection lid is made of stainless steel, and the inspection lid and the fitting are electrically connected. It is formed in an insulated state.

According to a second aspect of the present invention, there is provided a disconnector according to the first aspect, wherein an electrical insulation state between the inspection lid and the attachment is obtained by laying an insulating sheet on a surface of the inspection lid to be pressed. Things.

According to a third aspect of the present invention, there is provided the disconnector according to the first aspect, wherein the electrical insulation between the inspection lid and the fixture is provided with an insulator at the tip of the fixture. .

According to a fourth aspect of the present invention, there is provided the disconnector according to the first aspect, wherein the electrical insulation state between the inspection lid and the fixture is obtained by converting the fixture itself into an insulator.

[0011]

In the disconnector according to the present invention, the inspection lid of the outer cover is made of stainless steel, thereby suppressing eddy current flowing through the inspection lid and a rise in temperature associated therewith. In addition, since the inspection lid and the body are electrically insulated from each other by the jacket, the shunt of the jacket current is cut off to suppress local heat generation.

Further, an insulating sheet on the surface of the inspection lid is interposed between the inspection lid and the mounting member, so that the inspection lid and the body are electrically insulated.

Further, an insulator at the tip of the mounting member is interposed between the inspection lid and the mounting tool, and electrically insulates the inspection lid from the body.

Further, the mounting member made of an insulating material makes the inspection lid and the body electrically insulated.

[0015]

【Example】

Embodiment 1 FIG. Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing an inspection cover part in a jacket of a disconnector in a first embodiment of the present invention, and FIG. 2 is a line II- in FIG.
It is sectional drawing which followed II. In the figure, 9, 10, 1
Nos. 2 to 16 are the same as in the prior art, and a description thereof will be omitted. 23
Is an inspection lid made of stainless steel and has a plate thickness of 11
Is almost equivalent to Reference numeral 24 denotes an insulating sheet such as Teflon fixed to the edge surface of the inspection lid 23 by screwing or bonding.

Next, the operation will be described. By changing the inspection lid 23 from stainless steel to aluminum in the related art, the resistivity of the inspection lid 23 is increased, and eddy current due to the jacket current is suppressed, so that induction heating is moderated and a temperature rise is suppressed. In addition, since the insulating sheet 24 is interposed between the fixture 12 and the inspection lid 23, the electrical contact is eliminated, the shunt of the jacket current is eliminated, and the local heat generation due to the Joule loss at the contact portion is eliminated. FIG. 3 shows an experimental result at the time of applying a current of, for example, 25 kA, which proves this fact.
(A) shows measurement points a to h, and (B) shows measurement values obtained by comparing the conventional example with the first embodiment. By suppressing the temperature rise value at each point in this way, the size of the disconnector at the same rated current value can be reduced, and the size of the jacket increases due to the increase in the current value. An optimally sized disconnector can be obtained without any consideration.

Embodiment 2 FIG. In the first embodiment, the inspection lid 23 is provided with the insulating sheet 24 in order to eliminate the electrical contact between the inspection lid 23 and the fixture 12. However, as shown in FIG. An insulator, here an insulating sheet 25, may be attached to the tip of the fixture 12 using bolts 26 and nuts 27. Further, the insulating sheet 25 may be attached by tape or by adhesion. Further, the mounting fixture 12 as shown in FIG.
An insulator having a hole 28a into which the tip of the wire can be inserted may be an insulating cap 28 here.

Embodiment 3 FIG. Further, in the first and second embodiments, the structure in which the electrical contact is eliminated on the tip side of the metal fitting 12 is shown. However, as a third embodiment, as shown in FIG. , Stepped washer 30
May be used so as not to make electrical contact between the fixture 12 and the seat 13.

Embodiment 4 FIG. Further, even if the electric circuit between the inspection lid 11 and the body part 10 is cut off by making the fixture 12 itself a strong insulating member (not shown) such as reinforced plastic, the same as in the above embodiment. Effects can be obtained.

Further, in each of the above embodiments, the description has been given of the case where the disconnector is symmetrical. However, a phase separation bus having a configuration in which a CT or the like is inserted from an inspection port may be used, and the same effect as in the above embodiment can be obtained.

[0021]

As described above, according to the first aspect of the present invention, a pair of cylindrical contacts provided at the ends of the conductor and opposed to each other and spaced apart from each other and operate in the opposite direction with the contacts interposed therebetween. A disconnecting part formed by a movable contact that opens and closes an electric circuit when approaching and separating from the body, a body part covering the disconnecting part in a substantially concentric cylindrical shape and having an opening for inspection, and an inspection for closing the opening of the body part In a disconnector having a cover and a fitting formed by fixing the one end to the body near the opening and mounting the tip of the other end by pressing the surface of the inspection lid in this state, a material of the inspection lid is provided. Is made of stainless steel and the inspection lid and the mounting fixture are formed in an electrically insulated state, so that eddy currents flowing through the inspection lid and the accompanying temperature rise are suppressed, and the branch current of the jacket current is cut off to reduce local heat generation. Can be suppressed, and small in the same rated current range. The effect of reduction is capable disconnector is obtained.

According to a second aspect of the present invention, in the first aspect, the insulating sheet is laid on the surface of the inspection lid to be pressed, so that the insulating sheet is interposed between the inspection lid and the mounting member, and the inspection lid and the body are provided. The parts can be electrically insulated.

According to a third aspect of the present invention, in the first aspect, an insulating material is provided at a tip of the mounting fixture.
An insulator at the tip of the fixture is interposed between the inspection lid and the fixture, and the inspection lid and the body can be electrically insulated.

According to the fourth aspect of the present invention, in the first aspect, since the attachment itself is made of an insulating material, the inspection cover and the body can be electrically insulated by the attachment.

[Brief description of the drawings]

FIG. 1 is a plan view showing an inspection cover with a jacket of a disconnector according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is an explanatory view showing an experimental result for verifying the effect of the first embodiment.

FIG. 4 is a cross-sectional view illustrating a main part of a fixture for an inspection lid according to a second embodiment of the present invention.

FIG. 5 is a perspective view showing an insulating cap used as a fixture for an inspection lid in Embodiment 2 of the present invention.

FIG. 6 is a cross-sectional view illustrating fixing of a fixture for an inspection lid according to a third embodiment of the present invention.

FIG. 7 is a front view showing a partial cross section and an external configuration of a conventional disconnector.

FIG. 8 is a plan view showing an external configuration of a conventional disconnector.

FIG. 9 is a sectional view taken along line IX-IX in FIG.

FIG. 10 is a single-line diagram showing an example of a device configuration of a power plant.

FIG. 11 is a model diagram of a conventional jacket current and eddy current.

FIG. 12 is a model diagram of a shunt current flowing through a conventional inspection lid.

[Explanation of symbols]

1 fixed finger contact, 2 movable side conductor (one side conductor), 3 fixed contact, 4 fixed side conductor (other side conductor), 5 movable finger contact, 9 jacket, 10
Body, 10a opening, 12 fittings, 23 inspection lid,
24 Insulation sheet, 25 Insulation sheet (insulator), 28
Insulating cap (insulator).

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01H 33/28-33/59 H01H 31/02

Claims (4)

(57) [Claims] 1. A pair of cylindrical contacts provided at an end of a conductor and opposed to each other and spaced apart from each other, and a movable contact interposed between the contacts and operated in the facing direction to open and close an electric circuit by contact and separation with the contacts. A body part having a substantially concentric cylindrical shape covering the disconnection part and having an opening for inspection, an inspection lid for closing the opening of the body part, and a body near the opening at one end side. And a cover formed by a fixture fixed at the other end and having the other end pressed against the surface of the inspection lid in this state, the inspection lid is made of stainless steel and the inspection lid is made of stainless steel. A disconnector, wherein the inspection lid and the attachment are formed in an electrically insulated state. 2. The disconnector according to claim 1, wherein an electrical insulation state between the inspection lid and the fixture is obtained by laying an insulating sheet on a surface of the inspection lid to be pressed. 3. The disconnector according to claim 1, wherein the inspection lid and the fixture are electrically insulated from each other by providing an insulator at a tip of the fixture. 4. The disconnector according to claim 1, wherein the electrical insulation between the inspection lid and the fixture is obtained by converting the fixture itself into an insulator.