JPH05184043A - Cable head for connecting instrument - Google Patents

Abstract

PURPOSE:To permit the DC pressure resistance test of a cable line without impressing any high DC voltage on instruments by a method wherein a circuit is intercepted during charging a test voltage on the cable line and the intercepted part of the circuit is filled with insulating gas. CONSTITUTION:A cable head is provided with a cable connecting terminal A and a power charging terminal B. A conductor extracting rod 13 is provided in a bushing 11 and an electrically connecting member 15, connecting the cable connecting terminal A with the conductor extracting rod 13 electrically, is provided so as to be insertable into and extractable out of the bushing 11. Upon the DC pressure resistance test of the cable line 20, a space 10, generated by extracting the electric connecting member 15 out of the bushing 11, is filled with insulating gas introduced from the inside of an instrument. As a result, the conductor extracting rod 13 is intercepted electrically from the cable connecting terminal A and a testing DC voltage is impressed on only the cable line 20. According to this method, the DC pressure resistance test of the cable line 20 can be effected without impressing any high DC voltage on the instruments.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device connecting cable head for connecting a cable line and a device.

[0002]

2. Description of the Related Art When connecting high voltage equipment such as GIS (gas insulation circuit breaker) with a cable line, the following structure is generally adopted. FIG. 4 shows a side view of a conventional device and a device-connecting cable head. In the figure, a device 1 is, for example, a high voltage device such as the above-mentioned GIS, and a cable line 4 is connected to a wall surface 2 thereof via a bushing 3. The internal device 5 of the device 1 is electrically connected to the bushing 3 via a bus bar 6. The inside of the device 1 is insulated by an insulating gas 7 such as sulfur hexafluoride. Before installing such equipment, the equipment 1
It is necessary to perform an electrical test of the entire device after the bushing 3 and the like have been attached, in addition to individually performing an electrical test of the cable and the cable line 4. In this case, the cable line 4
A so-called alternating current (AC) withstand voltage test or the like is performed through which a test alternating voltage is applied.

[0003]

By the way, generally, the cable line 4 has an extremely large electrostatic capacity as compared with the device 1 and the like. Therefore, the so-called direct current (DC) withstand voltage test, in which a high direct current voltage is applied, can more accurately capture the electrical characteristics of the cable line 4. However, when the DC withstand voltage test is performed after connecting the cable line 4 to the device 1, the following problems occur. That is, the inside of the device 1 is filled with the insulating gas 7, but a considerable amount of dust is suspended in the insulating gas 7. Therefore, when a direct current high voltage is applied to the bus bar 6 and the like through the cable line 4, the dust is intensively attached to the inside of the device according to the so-called electrostatic precipitator principle. Therefore, this may reduce the insulation performance. For this reason, conventionally, there has been a problem that it is difficult to perform a DC withstand voltage test on the cable line 4 after being attached to the device 1. The present invention has been made in view of the above points, and a device connection cable that enables a DC withstand voltage test of a cable line connected to a device while preventing a DC voltage from being applied inside the device. The purpose is to provide a head.

[0004]

A first aspect of the present invention is a cable for receiving a terminal end of a cable line electrically connected to a device mounted on a wall surface of a device filled with an insulating gas. A connection end and a power supply end for receiving the end of a power supply cable for applying a test voltage to the cable line through the bushing are provided, and the internal circuit of the device is provided inside the bushing. An electric connection member for electrically connecting between the conductor withdrawing rod and the cable connection end portion connected to is arranged, and disconnecting the electric connection by the electric connection member by mounting the power supply cable to the power supply end portion, The present invention relates to a cable head for device connection, wherein an insulating gas is introduced from the inside of the device. A second invention of the present invention is a device connection characterized in that an insulating gas is introduced from the inside of the device to the vicinity of the electric connection member in the use state of the device in which the cable line and the device are electrically connected by the electric connection member. Cable head.

[0005]

The cable head is provided with a cable connection end A for connecting the cable line 20 and a power application end B for connecting the power application cable 30. In addition, a conductor withdrawing rod 13 connected to the internal circuit of the device is provided in the bushing 11, and an electrical connecting member 15 for electrically connecting the conductor withdrawing rod 13 and the cable connecting end portion A is arranged in the bushing 11 so as to be insertable and withdrawable.
During the DC withstand voltage test of the cable line 20, the insulating gas 16 is introduced from the inside of the device into the space created by withdrawing the electrical connection member 15. As a result, the conductor lead-out rod 13 and the cable connection end A are electrically disconnected from each other, and a DC test voltage is applied only to the cable line 20. If the insulating gas 16 is taken in from the inside of the device through the valve, the required minimum amount can be used.

[0006]

The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 shows an embodiment of a cable head for device connection of the present invention, in which (a) is a longitudinal sectional view thereof. Further, FIG. 3B is a vertical cross-sectional view of the cable head before mounting the electric connecting member 15. In the figure, the wall surface 2 of the device
A bushing 11 is fixed to the shaft via a fixing bolt 12. One end of the bushing 11 on the left side in the drawing penetrates a through hole 2A provided in the wall surface 2 of the device and projects into the device. Further, inside the bushing 11, a conductor pull-out rod 13 connected to the internal circuit of the device is provided. Further, an internal electrode 14 for electrically connecting with a cable line or a cable for charging, which will be described later, is arranged in the central portion of the bushing 11. The internal electrode 14 has a through hole 14a at the upper end.

Below the bushing 11, FIG.
A cable connection end A for receiving the end of the cable line 20 described with reference to FIG. On the right side of the bushing 11, a power supply cable 30 for applying a test voltage to the cable line 20 via the bushing 11.
Is provided for receiving the end of the power supply. This power-charging cable 30 is fixed to the power-charging end B of the bushing 11 by using a protective case 31. Further, a stress cone 32 is fitted on the insulator of the power charging cable 30 for reinforcing the insulation. The cable terminating configuration of the power charging cable 30 is the same as the terminating configuration of the conventional general high-voltage cable, and further detailed description will be omitted.

Here, in the cable head for device connection of the present invention, the conductor withdrawing rod 13 of the bushing 11 is used.
A tapered hollow portion 10 is provided between the inner electrode 14 and the internal electrode 14. An electric connection member 15 as shown in FIG. 1B is fitted into the hollow portion 10. As shown in FIG. 1B, the electrical connecting member 15 has a small diameter portion on the left side and a large diameter portion on the right side in the figure. This electrical connection member 15 is
It is composed of a tapered conductor corresponding to the hollow portion 10, and a spring-shaped contactor 15A is provided in the small diameter portion and the large diameter portion thereof.
Are provided respectively. This electrical connection member 15 is
As shown in FIG. 2, when it is fitted into the hollow portion 10 of the bushing 11, the contactor 15A provided in the small diameter portion is fitted into the recess of the conductor pull-out rod 13 and makes electrical contact. In addition, the contactor 15 provided on the large-diameter portion of the electrical connection member 15
A electrically contacts the inner wall surface of the through hole 14a of the internal electrode 14. As a result, the conductor extraction rod 13 and the internal electrode 1
An electrical connection with 4 is secured.

The fitted electrical connection member 15 is a fixing member 1.
Fixed at 7. The fixing bracket 17 is composed of a lid screwed into the through hole 14 a of the internal electrode 14. In that case, the blind end 40 is fitted into the charging end B and sealed by the lid 46. During such work, the valve 19 shown in FIG. 1 is closed to prevent the insulating gas from flowing out from the inside of the device.

On the other hand, as shown in FIG. 1 (a), when the charging cable 30 is attached to the charging end B, the insulating gas 16 is injected into the hollow portion 10 of the bushing 11. The insulating gas 16 is, for example, sulfur hexafluoride, and is introduced into the hollow portion 10 via a pipe 18 and a valve 19 attached to the wall surface 2 of the device. That is, no special tank or gas equipment is used to inject the insulating gas 16, and the insulating gas already used for the insulation inside the equipment is used as it is. When the hollow portion 10 is filled with the insulating gas 16 in this manner, even when a high DC voltage is applied to the internal electrode 14, a creeping short circuit on the inner wall surface 10A of the hollow portion 10 is prevented, and dielectric breakdown is prevented. be able to. That is, by filling the hollow portion 10 with the insulating gas 16 at a predetermined pressure,
A constant withstand voltage characteristic can be obtained.

The terminal portion of the charging cable 30 is shown in FIG.
As shown in (a), a plug 36 is attached which can be easily electrically connected by inserting the insulator 33 into the exposed conductor 34 by peeling it off. On the outer circumference of the plug 36, a contactor 36A is provided as with the electrical connection member 15. Therefore, by inserting the charging cable 30 into the through hole 14a of the internal electrode 14, the plug 36
The electrical connection with the internal electrode 14 is completed via.
A tulip contact 21 for receiving the end of the cable line 20 and making an electrical connection with the end of the cable line 20 is provided below the internal electrode 14.

FIG. 2 shows a vertical sectional view of the bushing in a normal use state after the DC withstand voltage test as described above is completed. As shown in the figure, the cable connection end A of the bushing 11
An end portion 24 connected to the conductor of the cable line 20 is inserted into the cable, and a tulip contact 21 makes an electrical connection with the internal electrode 14. The cable line 20 is fixed to the lower end of the bushing 11 by a protective case 23, and a stress cone 22 is fitted on the insulator to reinforce the insulation. The other cable terminating structures are the same as the configuration generally used in the past, like the cable 30 for charging.

On the other hand, when the power application cable 30 is not attached, the blind plug 40 is fitted in the power application end B as shown in FIG. Electrode plates 41 and 42 are provided on the high pressure side and the low pressure side of the blind plug 40, respectively, and the other portions are made of insulating rubber 43. In addition, the voltage applying end B is hermetically sealed by the lid 46 and the bolt 45. A spring 44 is inserted between the lid 46 and the recess of the electrode plate 42, and the spring 44 presses the blind plug 40 against the tapered inner wall surface of the charging end B of the bushing 11. In this state, the electrical connection member 15 described above with reference to FIG. 1B is fitted into the tapered hollow portion 10 of the bushing 11.

The device connecting cable head of the present invention having the above-mentioned structure is used as follows. FIG. 3 shows an operation explanatory diagram in the use state of the device connection cable head of the present invention. FIG. 3A is an operation explanatory diagram in the DC withstanding voltage test, and FIG. 3B is an operation explanatory diagram in a normal use state.
In FIG. 3 (a), when a DC high voltage is applied to the cable line 20 using the charging cable 30 and a DC withstand voltage test is performed, as shown in FIG. 1 (a), The power application cable 30 is attached to the power application end B. Further, the cable line 20 is mounted as shown in FIG. Then, the valve 19 is opened in the hollow portion 10 of the bushing 11 to fill the insulating gas 16. In this state, a high DC voltage is applied to the cable line 20 from the charging cable 30. On the other hand, for the conductor pull-out bar 13,
The high DC voltage is cut off by the insulating gas 16, and the high DC voltage is not applied inside the device.

On the other hand, after the DC withstand voltage test is completed, the valve 19
Is closed, and the electric connection member 15 is fitted into the hollow portion 10 as shown in FIG. Then, the blind plug 40 is attached. As a result, the cable line 20 and the conductor extraction rod 1
3 is electrically connected via the electric connection member 15. Therefore, the normal use as described above with reference to FIG. 2 becomes possible.

The present invention is not limited to the above embodiments. When the cable connection end portion A and the charging end portion B are provided on the bushing 11, their positions and numbers may be arbitrary. Also,
The shapes of the conductor lead-out rod 13 and the electric connecting member 15 may be freely changed within the range where the above-mentioned object is achieved. For example, the electric connecting member 15 may have various structures such as a switch-like member inserted between the conductor lead-out rod 13 and the internal electrode 14 and a member for opening and closing the gap. In either case, in order to prevent the DC voltage from being applied to the inside of the equipment during the test of the cable, the insulating gas
Any structure can be used as long as 6 can be injected.

When the electric connecting member is a knife switch or a switch that opens and closes a gap, many voids are formed in the vicinity of the periphery of the electric connecting member. Therefore, it is preferable to ensure electrical insulation even in the use state of the device in which the cable line and the device are electrically connected.
For this purpose, it is preferable to open the valve again after the start of use of the device so that the insulating gas is introduced around the electrical connection member.

[0018]

As described above, according to the cable head for device connection of the present invention, an electric connection member for electrically connecting the conductor draw-out rod and the cable connection end portion is provided inside the bushing, and the power supply cable is provided. While the test voltage is being applied to the cable line by using, the circuit is cut by removing the electrical connection member, etc. and the insulating gas is filled in the circuit cut part, so a high DC voltage is applied to the equipment. The DC withstand voltage test of the cable line can be carried out without doing so. As a result, during the DC withstand voltage test of the cable line,
High DC voltage is applied inside the device, and there is no risk of dust adhering to the inner wall of the device. In addition, by introducing insulating gas from the inside of the equipment to the bushing side through a valve, equipment such as a gas cylinder is not required, and testing can be performed using the minimum required insulating gas, which improves workability. , Has an excellent effect in terms of economy. In addition, by checking and cleaning the hollow portion of the bushing 11 when attaching or detaching the electrical connecting member, it is possible to maintain high electrical characteristics and further improve reliability.

[Brief description of drawings]

1A and 1B show an embodiment of a cable head for device connection of the present invention, in which FIG. 1A is a vertical cross-sectional view thereof, and FIG. 1B is a vertical cross-sectional view of a cable head for device connection at a preparation stage of a DC withstand voltage test. is there.

FIG. 2 is a vertical cross-sectional view of the cable head for device connection of the present invention during normal use.

FIG. 3 is an operation explanatory view of the device connection cable head of the present invention.

FIG. 4 is a vertical cross-sectional view of a conventional general device and a cable head.

[Explanation of symbols]

 2 Wall surfaces of equipment 10 Hollow part 11 Bushing 15 Electrical connection member 16 Insulating gas 20 Cable line 30 Cable for power distribution A Cable connection end B B Power distribution end

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI Technical display location H02G 1/06 Q 7373-5G (72) Inventor Masaki Ikuta Toshiba Town, Fuchu City, Tokyo Toshiba Fuchu Factory (72) Inventor Nobuyuki Sema 2-1-1 Oda Sakae, Kawasaki-ku, Kawasaki-shi, Kanagawa Showa Electric Wire & Cable Co., Ltd.

Claims (2)

[Claims] 1. A bushing attached to a wall surface of a device filled with an insulating gas, a cable connecting end for receiving an end of a cable line electrically connected to the device, and the cable through the bushing. A line is provided with a power-supply end for receiving the end of a power-supply cable that applies a test voltage, and inside the bushing, a conductor pull-out rod connected to the internal circuit of the device and the cable connection end. An electric connection member for electrically connecting the parts is arranged, and the electric connection by the electric connection member is cut by mounting the power supply cable to the power supply end portion, and the circuit disconnection portion is connected from the inside of the device. A cable head for device connection, wherein the insulating gas is introduced. 2. A cable head for device connection, wherein an insulating gas is introduced from the inside of the device into the vicinity of the vicinity of the electrical connection member when the device is used for electrically connecting the cable line and the device with the electrical connection member. ..