JPS63284727A - Switch tower - Google Patents

Abstract

PURPOSE:To make a switch tower small-sized, simplify the cable connection work, and reduce the cost by incorporating operation power supply transformers in a gas switch in the switch tower storing a high-voltage cable direct-coupled high-voltage automatic switch, its control box, and the operation power supply transformers. CONSTITUTION:An SF6 gas-sealed automatic switch 2 storing transformers 4, 4 is arranged in the outer box of a power distribution board. A control box 3 is provided on the side of the outer box 1, a high-voltage main circuit direct- coupled terminal 7 is connected to the terminal section of the switch 2 via a high-voltage main circuit bushing 5. The high-voltage main circuit direct- coupled terminal 7 incorporates a connection terminal 7a, one end of which is connected to a main terminal 5b in the high-voltage main circuit bushing 5 for connection to the switch 2, and the other end is connected to a high- voltage main circuit cable 6. The structure and work to extract an operation circuit cable for a transformer from the high-voltage main circuit bushing 5 are thereby not required, the connection work is simplified, and a switch tower can be made small-sized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a switch tower with an operating power supply transformer inside.

[Conventional technology]

There is an increasing demand for undergrounding overhead power distribution lines for reasons such as urban environmental improvement and disaster prevention.

The block diagram shown in FIG. 5 shows an underground power distribution system developed by the applicant and others. In the figure, SS is a substation, and M is a main switch tower that is normally open but is turned on to accommodate power from other substations in the event of an accident.
B is the branch switch tower used at the branch point from the main line to the layer side, H is the relay to the next layer side, the lead-in point to the high-voltage consumer, and the transformer for low-voltage consumers such as general households. The roof switch tower used as the lead-in point to the base Tr is shown.

Switch towers are equipped with automatic switches, depending on the type mentioned previously.
Built-in control box, remote control slave unit, connection terminal box, etc.

This power distribution system takes the conventional sectional switch system underground and goes even further by adopting remote III control.
This is an attempt to automate the process.

In general, high-voltage cable direct connection type switchboards used in such switch towers have a structure in which the live parts of high-voltage equipment are completely insulated and not exposed for safety reasons, and the insulating jacket is equipped with an earth shield. It has a structured structure.

Figures 6 and 7rI! I is a front view and a side view showing the arrangement of equipment in a typical switch tower. As shown in these figures, the switch tower typically contains SFs within the outer box 21.
Gas filled automatic switch 22 and control box 23 that controls it
The control circuit in the control box 23 houses an operating power transformer 24 for obtaining operating power from the main circuit side. The switch is equipped with a main circuit bushing 25, and as shown in FIG.
A main terminal 25b is formed at the tip of the main current portion 25a, and a side terminal 25c is provided laterally from the middle of the main current portion 25a. A direct connection terminal 27 of the high voltage main circuit cable 26 is connected to the main terminal 25b.
A direct connection terminal 29 of the high voltage operating circuit cable 28 is connected to the bypass terminal 25c. A direct connection terminal 30 is provided at the other end of the operating circuit cable 28, and is connected to the high voltage side (-
connected to the next side) terminal. 27a is a terminal for voltage detection.

FIG. 9 shows the internal structure of the gas-filled automatic switch 22. In the figure, 31 is a movable contact, 32 is a fixed contact, 33 is a drive arm, 34 is a main shaft, and 35 is a current collecting contact.

[Problem that the invention seeks to solve]

In such a conventional switch tower housing an operating power transformer, as shown in FIG.
6, the high voltage main circuit bushing 2 of the switch
It is necessary to provide a bypass terminal 25C to connect the operating circuit cable having a direct connection terminal 29 to the terminal 5, or to separately provide a high-voltage pull-out bushing exclusively for the operating circuit.
Requires complex structure. Further, since the operating circuit cable required for connection has direct connection terminals 29 at both ends, processing of the terminals requires highly specialized technology and is expensive. Furthermore, a large space is required for connecting the cable.

As mentioned above, in an underground power distribution system, each switch tower is installed on a walkway or the like above ground to facilitate maintenance and inspection. This switch tower is required to be as small as possible so as not to greatly block the field of view or become an obstruction to traffic.

Therefore, the present invention aims to reduce the size of such a switch tower,
The purpose is to simplify cable connection work and reduce costs.

[Means for solving problems]

In order to achieve this object, the switch tower of the present invention houses a high-voltage automatic switch directly connected to a high-voltage cable, its control box, and an operating power transformer, in which the operating power transformer is connected to a gas switch. It is characterized by having a built-in

〔Example〕

Hereinafter, the present invention will be specifically described based on embodiments shown in the drawings. FIGS. 1 and 2 are a front view and a side view showing the arrangement of equipment in this embodiment, and the outer box 1 of the switchboard is an SF with a built-in transformer 4.4.

A gas-filled automatic switch 2 is arranged. A control box 3 is installed on the side of the outer box 1, and a high voltage main circuit direct connection terminal 7 is connected to a terminal portion of the switch 2 via a high voltage main circuit bushing 5. The high voltage main circuit direct connection terminal 7 has a built-in connection terminal 7a as shown in FIG. 3, one of which is connected to the main terminal 5b in the high voltage main circuit bushing 5 for connection to the switch 2
The high voltage main circuit cable 6 is connected to the other end. 7b is a terminal for voltage detection.

FIG. 4 shows an example of the interior and structure of the automatic switch 2 having a built-in transformer 4. As shown in FIG. In the figure, 11 is a movable contact, 12 is a fixed contact, 13 is a drive arm, 14 is a main shaft, and 15 is a current collecting contact. As shown in Fig. 4, the switch case 2
A partition plate 2b is provided to partition the inside of a into upper and lower parts, and a lower chamber 2C is provided.
The contact portion is housed in the upper chamber 2d, and the operating transformer 4 is housed in the upper chamber 2d, and each is filled with gas. In the main circuit bushing 5.5 on the power supply side and the load side, the tip 5a of the conductive part in the bushing and the fixed contact side terminal and the movable contact side terminal are connected with a conductive material. The operating wire 17.1 is inserted from the movable side and fixed side terminals through the bushing 16.16 that passes through the partition plate 2b.
7 to operate the primary side (high voltage side) terminals 4a, 4 of the transformer.
Connect to a. Secondary side (low voltage side) terminal 4b of the transformer,
4b, an operating circuit power supply line 19, 19 is drawn out to the outside via a low-voltage operating circuit bushing 18 that passes through the case 2a. Since the bushings 16, 16 are located in the gas-filled chamber, the operating wires, the bushings 16, etc. can be of simple construction, with sufficient insulation to withstand high pressure, and of simple construction. Since the inside of the case 2a is a gas-filled chamber and the pressure is low, the bushing 18 may have a simple structure in terms of insulation. However, a structure that takes gas sealing measures into consideration is required.

Because the transformer is built into the gas switch, the materials of the parts that make up the transformer are designed to minimize the generation of miscellaneous gases that would deteriorate gas characteristics, and to ensure that they are not affected by gas or decomposition gas. We have selected products suitable for use in gas, and have also taken measures such as controlling the moisture contained in the gas in the gas switch and installing gas adsorbents to remove decomposed gas and unnecessary gas.

〔Effect of the invention〕

As explained above, in the present invention, the operating power transformer is housed inside the gas-filled switch. This eliminates the need for the structure and work of pulling out the transformer operating circuit cable from the bushing of the high-voltage main circuit. In other words, the switch main circuit bushing can omit the side terminal for drawing out the high-voltage operation circuit, so there is no need for a complicated structure like in the past, and a small bushing for the low-voltage circuit is sufficient for the operation circuit. The terminal structure can also be simple, for example, an amplifier terminal connection. Therefore, the connection work can be simplified and the material cost can be reduced. In addition, the connection with the transformer terminal is made inside the gas-filled interior, which improves insulation, allows for a smaller connection space, and improves connection reliability.

As described above, the size of the switch case can be reduced, and a switch tower suitable for an underground power distribution system can be provided.

[Brief explanation of drawings]

Fig. 1 is a front view showing the arrangement of equipment in an embodiment of the present invention, Fig. 2 is a side view thereof, Fig. 3 is a sectional view of the main circuit bushing simplified in the present invention, and Fig. 4 is the present invention. 5 is a block diagram of an underground power distribution system proposed by the applicant, and FIG. 6 is a front view showing the arrangement of equipment in a conventional switch tower. 7 is a side view thereof, FIG. 8 is a sectional view of a conventional main circuit bushing, and FIG. 9 is a diagram of the internal structure of a conventional automatic switch. ■ = Outer box 2: Gas-filled automatic switch 2a: Switch case 2b: Partition plate 2C: Lower chamber 2d: Upper chamber 3: Control box 4: Primary side terminal of operation power transformer 4a 4h; Secondary side terminal 5 : High voltage main circuit bushing 6: Cable 7: Direct connection terminal for high voltage main circuit 8: Movable contact 9: Fixed contact 10: Drive arm 11: Main shaft 12: Current collector contact 13; Drive arm 14: Main shaft
15: Current collector contact 16: Bushing 17; Operation wire 18: Bushing for low voltage operation circuit 19: Operation circuit power supply line Patent applicant: Togami Electric Manufacturing Co., Ltd. (and 2 others) Agent: Masu Kobori (and 2 others) Figure 1 r! Figure 3 Figure 4 il 2 ■

Claims (1)

[Claims] 1. A switch tower housing a high-voltage automatic switch directly connected to a high-voltage cable, its control box, and an operating power transformer, characterized in that the operating power transformer is built into the gas switch.