JPH0350372B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a grounded tank type puffer type gas shield and breaker which compresses arc extinguishing gas by a piston and cylinder device during the circuit breaker tripping operation. It is something.

(Technical Background of the Invention) With the recent increase in high voltage and capacity in power systems, the short-circuit current that must be immediately cut by a circuit breaker increases rapidly, and the short-circuit current that is applied to a circuit breaker after the current is interrupted is rapidly increasing. Voltages also tend to increase. Generally, arc-extinguishing gas is compressed by a cylinder and piston,
In puffer-type gas shields and disconnectors that spray gas onto an arc that occurs between contacts, the arc-extinguishing gas is heated by the energy generated from the arc when it passes through the arc, and flows downstream as hot gas. Sprayed. This hot gas contains electrode vapor and decomposition products generated by the reaction between these and the arc-extinguishing gas, and due to the non-uniform density due to the gas flow, the dielectric strength of this hot gas is higher than that of the gas at rest. causes a decrease in This phenomenon has been a drawback for the purpose of increasing the shearing performance per unit. Therefore, one way to improve the insulation performance is to improve the flow path on the downstream side so that the high-temperature gas flow is not guided to areas where the electric field strength is high. Figure 1 shows a conventional example of an arc extinguishing chamber for a grounded tank type puffer type or disconnector. The arc-extinguishing gas compressed by the puffer piston 5 and puffer cylinder 6 is blown through the insulating nozzle 3 onto the arc 8 generated between the fixed arc contact 2 and the movable arc contact 4. Arrows indicate gas flow. The arc-extinguishing gas that has passed through the arc 8 turns into hot gas as described above, and is exhausted from the exhaust port A attached to the base of the fixed current-carrying contact 1 into a wider tank interior space. In such a conventional structure, the hot gas flows through the fixed arc contact mounting portion 9 as shown by the arrow in FIG.
The direction of the flow changes along , resulting in a direction towards the tank wall 7, so that under high voltage conditions,
A flash fault 10 often occurs from the vicinity of the corner of the fixed arc contact attachment part 9, where the electric field strength is stronger than that of the surrounding area, to the tank 7, resulting in a drawback that the shearing performance cannot be improved.

(Object of the Invention) The present invention has been made in view of the above points, and its purpose is to prevent flash shorting to the tank even if a high-temperature gas flow is blown to the above-mentioned fixed arc contact attachment part. After the current is cut off,
An object of the present invention is to obtain a grounded tank type puffer type gas shield and disconnector which improves the withstand voltage characteristics between a fixed contact side component and a tank.

(Embodiment of the Invention) Next, the present invention will be described based on an embodiment shown in FIG. 2, in which the same parts as in FIG. 1 are denoted by the same reference numerals. FIG. 2 shows a cross section around the fixed contact and fixed arc contact attachment parts, with a movable part on the right side (not shown). 1a is a shield that covers a fixed current-carrying contact 1b in the case of a circuit breaker with a large current, and forms a fixed electrode portion together with a fixed arc contact 2 disposed within this contact 1b. In addition, when the energizing current is small and the fixed energizing contact 1b is not required, the above-mentioned fixed energizing contact 1
The part b is used as a shield that electrically covers the fixed arc contactor 2. The fixed arc contactor 2 can be treated as a fixed electrode. 20
are these shield 1a and fixed current-carrying contact 1b
This is the member to which the is attached. The mounting member 20, fixed current-carrying contact 1b, and shield 1a act as a shielding member for the fixed (arc) contact 2. The mounting member 20 is made of a plurality of metal pieces arranged such that the distance B from the central axis 12 of the fixed arc contact 2 to the outermost part thereof decreases toward the fixed arc contact mounting part 9. Pillar making 1
1 to the fixed arc contact mounting portion 9. In addition, the outer diameter A of the fixed arc contact mounting portion 9
and the outer diameter B of the larger of the member 20 or the shield 1a, so that the following relationship is maintained.

A<B An example of the structure of this pillar 11 is shown in FIG. 3 in a cross section viewed from the direction indicated by the two-dot chain arrow 13 in FIG.
FIG. 3a shows a case where the cross section of the column 11 is approximately circular, b,
c is approximately oval, d is approximately fan-shaped or triangular, and e is approximately oval. The corners of these pillars 11 are all rounded.

(Effects of the Embodiment) With the above configuration, hot gas is blown near the fixed arc contact mounting portion 9, which is not much different from the conventional example as shown by the arrow in FIG. In particular, by using the pillar 11, a part of the pillar 11 is
Since the hot gas is exhausted outside the gap between the pillar 11 and the column 11, the amount of hot gas blown onto the mounting portion 9 is reduced. Furthermore,
Since the outer diameter of the fixed arc contact attachment portion 9 can be configured to be small, the attachment portion 9 to the tank 7 can be configured to have a small outer diameter.
It is possible to sufficiently lower the electric field of the tank 7, and it is possible to provide a grounded tank type puffer type gas shield and disconnector with excellent withstand voltage characteristics between the fixed contact side component and the tank 7 after the current is interrupted. .

In addition, in the embodiment, the central axis 1 of the fixed arc contact
2, the pillars 11 are drawn symmetrically and with the same shape, but even if asymmetrical pillars with different cross-sectional shapes are combined, each pillar will have a different distance from the central axis 12 to the outermost side. You can leave it on.

(Overall Effects) As explained above, according to the present invention, a shielding member that covers the fixed electrode electrically around the central axis of the fixed electrode whose one side is fixed to the fixed electrode mounting member is attached to the outer periphery of the fixed electrode. The shield member is disposed near the tip and supported by a plurality of pillars so that the distance from the central axis of the shield member to the outermost diameter of the shield member located at the outermost side decreases toward the fixed electrode mounting member. Since the outer diameter of the fixed electrode mounting member is made smaller than the diameter of the shield member, the amount of hot gas blown onto the fixed electrode mounting member can be reduced, and the outer diameter of the fixed electrode mounting member can be reduced. Since the structure can be made small, the electric field of the mounting member can be made sufficiently low, and it is possible to provide a grounded tank type puffer type gas shield and disconnector with excellent withstand voltage characteristics.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing a conventional example, Fig. 2 is a sectional view of a fixed contact side portion showing an embodiment of the present invention, and Figs. It is a sectional view showing an example. 2...Fixed arc contactor, 3...Insulated nozzle,
4...Movable arc contactor, 5...Puff puff piston, 6...Puff puff cylinder, 7...Tank, 8
...Arc, 9...Fixed arc contact mounting part, 1
0...Senkou, 11...Pillar, 12...Central axis, 20
...Mounting parts.

Claims (1)

[Claims] 1. Arc-extinguishing gas in the cylinder is compressed by the cutting action of the movable electrode, and the arc is blown by spraying this gas onto the arc generated between the movable electrode and the fixed electrode. In the case where the cut section is housed in a grounded tank, a shield member for electrically covering the fixed electrode is arranged near the outer peripheral tip of the fixed electrode, and the shield member is placed at a distance from the central axis of the fixed electrode. The fixed electrode is supported on the fixed electrode mounting member via a plurality of pillars that are arranged so as to decrease toward the fixed electrode mounting member to which one side of the fixed electrode is fixed, and the outer diameter of the fixed electrode mounting portion is is smaller than the outer diameter of the shield member, and the gas is exhausted from between the pillars. 2. The grounded tank puffer type gas shield disconnector according to claim 1, wherein the cross-sectional structure of the pillar is approximately circular or approximately oval. 3 The cross-sectional structure of the pillar is approximately triangular or fan-shaped,
The grounded tank type puffer type gas shield and disconnector according to claim 1, wherein the corners are rounded. 4. The grounded tank puffer type gas shield disconnector according to claim 1, wherein the shield member has a fixed current-carrying contact attached to the inside of the shield, and the fixed electrode is a fixed arc contact.