JPH0353525Y2 - - Google Patents

Description

[Detailed description of the invention] "Industrial Application Field" This invention relates to electrical equipment for transmitting and receiving electricity used in substations, etc., which uses hollow bushings for connections with overhead power transmission lines.

"Prior Art" Fig. 3 shows an example of a gas circuit breaker with a conventional structure.The right half of the circuit breaker is omitted because it is almost the same as the left half. , a hollow bushing 2, a cutoff part 3, a conductor 4 that penetrates the hollow bushing 2 and connects the cutoff part 3 and the external wire, and a conductor 4 supported at one end by the terminal block 1.
A support insulator 6, a tank 7, and a current transformer 8 that support the opposite end of the block and also support the fixed contact part 5 of the cutoff part 3.
It consists of etc. Reference numeral 9 denotes a lead-in portion provided in the tank 7 for mounting the current transformer 8. In the space sealed by the tank 7 and the hollow bushing 2,
It is filled with an insulating medium 10 such as SF6 or a mixed gas of SF6, which is also effective in interrupting current. Further, reference numeral 11 denotes a shield metal fitting, which relieves the electric field strength at the support metal fitting 13 of the hollow bushing 2. In other words,
Since the supporting metal fitting 13 of the hollow bushing 2 has an edge-shaped part 14 with high electric field strength, it is better to provide the shielding metal fitting 11 even if the insulation distance is sacrificed a little, and the size can be reduced, which is advantageous in terms of design. is large.

"Problems that the invention attempts to solve" In the conventional structure explained in Figure 3,
Since the shielding fitting 11 is arranged at a remote distance from the conductor 4 for insulation, the inner diameter of the hollow bushing 2 becomes large, which in turn increases the size and weight of the hollow bushing 2 itself, impairing economic efficiency. It's also summer. Further, along with this, the current transformer 8 has to be installed outside the enlarged lead-in portion 9, and the current transformer 8 also becomes large, reducing economic efficiency. That is, not only is the inner diameter dimension of the current transformer 8 restricted;
Since the current transformer 8 detects the induced current due to the current flowing through the conductor 4, the inductive effect decreases as the distance from the conductor 4 increases, so it is necessary to increase the number of windings to compensate for this, making it even larger. This results in an increase in weight. In addition, since the conductor 4 is supported between the terminal block 1 and the support insulator 6 at two points that are widely separated, instability in terms of strength and dimensional accuracy is unavoidable. Furthermore, since the insulating medium 10 in the hollow bushing 2 is in communication with the blocking part 3, the insulating medium 10 in the hollow bushing 2 has no choice but to be transported in one piece, which may be subject to restrictions such as road transportation.

"Means for Solving the Problem" A condenser bushing is arranged concentrically inside the hollow bushing at a position where the mounting part is approximately flush with the support fitting at the lower end of the hollow bushing, and one end of the condenser bushing is The condenser cone portion protrudes upwardly from the support fitting at the lower end of the hollow bushing, and the outer periphery of the condenser cone portion at the other end of the condenser bushing,
This is due to the placement of a current transformer inside the tank.

Embodiment FIG. 1 shows one phase of a gas circuit breaker showing an embodiment of the present invention, and the right half is omitted because it is substantially the same as the left half. A detailed explanation will be given below, but some of the parts that are the same as those in the conventional system are given the same reference numerals as those in FIG. 3, and a part of the explanation will be omitted. The circuit breaker has a hollow bushing 2
2. Consists of a disconnection section 3, a capacitor bushing 15, a conductor 16 connecting the capacitor bushing 15 and the terminal block 1, a connecting conductor 17 connecting the capacitor bushing 15 and the disconnection section 3, a current transformer 21, etc. There is. Tank 27 and hollow bushing 22
The hollow portion sealed with the like is filled with an insulating medium 10. A feature of the present invention is the use of a capacitor bushing 15. That is, the condenser bushing 15 is located approximately concentrically inside the hollow bushing 22, and the mounting portion 18 is located on the inside of the hollow bushing 22.
The support fitting 23 is located concentrically and in the vicinity of the inner side of the support fitting 23. Further, the capacitor cone portion 19 on the upper side of the capacitor bushing 15 protrudes in the upper end direction beyond the support fitting 23 portion, and is connected to the outer periphery of the condenser cone portion 20 at the lower end of the capacitor bushing 15 and a current transformer in the tank 27. 21 are arranged. Since the outermost circumference of the condenser cone 20 has almost the same potential as the ground, the current transformer 21
can be placed close to the condenser cone 20 in the tank 7. As a result, the current transformer 21 is small;
The reduced weight improves economic efficiency, and the retracting portion 9 shown in FIG. 3 is no longer necessary, and the tank 27 is also simplified, making it possible to further reduce costs. Although the dimensions of the condenser cone 19 are longer than those of the conductor 4 in the conventional structure shown in FIG. Since this is not necessary, the inner diameter of the hollow bushing 22 becomes smaller as a result. Therefore, hollow bushing 2
2 can also be miniaturized and is economical. In addition, since the conductor 16 is supported by the terminal block 1 and the capacitor bushing 15 which are close to each other, there is no need to worry about strength and dimensional accuracy is stable. Furthermore, since the connecting conductor 17 is supported by the capacitor bushing 15, the supporting insulator 6 shown in FIG. 3 may be omitted in some cases. Furthermore, since the insulating medium 10 can be divided into two parts by the attachment part 18 of the capacitor bushing 15, by separating the hollow bushing 22 during transportation, it is possible to do it outside the limits of the Road Traffic Act. It is. Note that insulating medium 1
If 0 is not divided, communication can be easily established by drilling a hole in the mounting portion 18 of the condenser bushing 15.

The present invention has been explained above using a gas circuit breaker as an example, but the present invention can also be applied to other transmission systems using hollow bushings.
It can also be applied to electrical equipment for receiving power. As an example, a case where the present invention is applied to a gas insulated switchgear will be explained with reference to FIG. FIG. 2 shows the connecting portion of the gas insulated switchgear to the overhead line, and the same parts as those in FIG. 1 are given the same reference numerals and redundant explanation will be omitted. In FIG. 2, transportation constraints are avoided, and operation is made more economical by eliminating duplication, such as having gas pressure management in two locations, one in the hollow bushing 22 and the other in the tank 27, due to the division of the insulating medium 10. In order to achieve this, the insulating medium 10 is divided into two by the condenser bushing 15, and the piping
and an on-off valve 25 to enable communication. However, whether or not to divide the insulating medium 10 into two is as follows.
This should be decided based on the overall specifications.

``Effects of the invention'' - Small hollow bushings can be used, making the equipment lighter and more economical.

- Since current detection using induced current becomes easy, a small current transformer can be applied, which is economical and reduces the weight of the equipment.

- The tank structure is simplified and economical.

- The strength and dimensional accuracy of the conductor that passes through the hollow bushing is improved.

- Since the hollow bushing can be configured to be freely separable, restrictions during transportation can be removed.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing an example in which the present invention is applied to a gas circuit breaker, Fig. 2 is a cross-sectional view showing an example of application to a gas-insulated switchgear, and Fig. 3 is a cross-sectional view showing an example of a conventional structure. be. In the figure, 10 is an insulating medium, 15 is a capacitor bushing, 16 is a conductor, 18 is a mounting part, 19, 20 is a capacitor cone part, 21 is a current transformer, 22 is a hollow bushing, 23 is a support fitting, 24 is piping, 25 is an opening/closing part, and 27 is a tank.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A transmission consisting of a hollow bushing through which a conductor connected to an external electric wire passes and is filled with an insulating medium, and a tank that houses the main equipment and is filled with an insulating medium; In an electrical device for receiving power, a capacitor bushing having a mounting portion substantially in the same plane as a support fitting at the lower end of the hollow bushing is disposed inside the hollow bushing concentrically, and a capacitor cone portion at one end of the capacitor bushing is arranged. An electrical device for transmitting and receiving power, comprising: a current transformer that protrudes upward from the support fitting at the lower end of the hollow bushing and is disposed on the outer periphery of the condenser cone portion on the other end of the condenser bushing and within the tank; 2. The electrical equipment for transmitting and receiving power according to claim 1 of the utility model registration claim, characterized in that SF6 gas or a mixed gas of SF6 is used as the insulating medium filled in the hollow bushing and the tank. 3. Electrical equipment for power transmission and reception according to claims 1 and 2 of the utility model registration, characterized in that the hollow bushing communicates with an insulating medium filled in a tank housing the main equipment. 4. Utility model registration request for a condenser bushing, characterized in that the insulating medium is divided into two parts: the tank housing the main equipment and the hollow bushing, and the insulating medium can be communicated with each other through piping and a shut-off valve. Electrical equipment for power transmission and reception as described in scope 1 and 2.