JPH0628126B2 - Closed switch - Google Patents

Description

The present invention utilizes the internal pressure of an arc short circuit to reduce the arc energy when an arc short circuit occurs in a switch,
The present invention relates to a closed switch having a mechanism that short-circuits a short-circuit bar when the pressure relief valve is opened.

(Prior art) When a short-circuit accident occurs inside a closed high-voltage switch that uses air or insulating gas as an insulating and extinguishing medium, the pressure inside the switch rises due to this short-circuit accident and the switch is deformed. Then, it releases hot gas to the outside or explodes.

Therefore, a pressure relief valve, etc. is provided in advance on the side wall of the switch, and as the internal pressure rises, the pressure relief valve is deformed or operated to break the seal of the switch and release pressure from the location, preventing deformation or explosion of the switch. I'm out.

(Problems to be Solved by the Invention) However, the size of the pressure relief valve is limited to some extent because it must be hermetically closed at all times and there is a space for the switch. Moreover, when an internal short circuit accident occurs in the switch, the short circuit arc continues until the circuit breaker on the power supply side of the switch breaks. Therefore, a considerable amount of high-temperature gas is generated, which may damage the switch, and the high-temperature gas released to the outside of the switch may cause damage to passersby and the like.

Therefore, the present invention provides a switch that reduces the arc energy of a short-circuit arc that occurs during such an internal short-circuit accident and prevents damage to equipment and damage to passersby due to long-term generation of high-temperature gas. It is intended for.

(Means for Solving the Problem) Therefore, according to the present invention, in a closed switch having a normally closed pressure release valve that opens a pressure release port by an internal pressure equal to or higher than a certain value, three types of power source side and load side are provided. Each short-circuit contact piece is provided from the conductor that leads to the electrode of each phase, and one short-circuit bar that can contact the three-phase short-circuit contact piece on the power supply side and the other short-circuit contact piece that can contact the three-phase short-circuit contact piece on the load side A short-circuit bar is provided, each of these short-circuit bars is supported by an operating plate, and this operating plate and the pressure release valve are integrally connected by an operating pestle, and the pressure release valve uses a bullet to close the pressure release port. When the pressure relief valve is energized and the pressure relief valve is closed, each short-circuit bar separates from each short-circuit contact piece, and when the pressure relief valve opens, each short-circuit bar contacts each short-circuit contact piece. It is equipped with a lock mechanism that locks it when it comes into contact with.

(Operation) If a short circuit occurs in this switch and an arc occurs, the pressure in the switch rises. When this internal pressure rises above a certain value, the pressure relief valve opens the pressure relief port, and hot gas is discharged from the pressure relief port to the outside of the switch. The short-circuit bar moves with the movement of the pressure control valve, and the short-circuit contact pieces of the three-phase power supply side or the three-phase short-circuit contact pieces of the load side come into contact with each short-circuit bar. Locked in contact. As a result, the arc is extinguished because the arc short circuit transitions to the metal short circuit.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

Three-phase bushings 2, 2'are provided on one side wall of the closed switch main body 1 on the power supply side and the load side, respectively, and a cable is provided on the outside of the switch main body 1 of each of these bushings 2 or 2 '. The connection terminals 3 and 3'are connected to each other, and the conductor 4 is connected to each bushing 2 or 2'inside the switch body 1. Corresponding three-phase conductors 4 and 4'on the power supply side and the load side
Is guided to an opening / closing contact mechanism section 5 in the switch body 1, and can be freely contacted and released in the opening / closing contact mechanism section 5. Further, a pressure relief port 6 is provided on one side wall of the switch body 1 between the power source side bushing 2 and the load side bushing 2 ', and the pressure relief port 6 is provided with an outer peripheral edge 6a, and The pressure release port 6 is covered with a lattice plate 7. Further, the lattice plate 7 has a hole at the center thereof, and the operating punch 8 is slidably inserted through the hole. A pressure relief valve 9 is fixed to the outer end of the operating pestle 8 projecting outward of the switch body 1, and the pressure relief valve 9 abuts the outer peripheral edge 6a of the pressure relief port 6 to close the pressure relief port 6. It can be opened freely. An operating plate 10 is fixed to the inner end of the operating rod 8 located inside the switch body 1 of the operating rod 8. A spring spring 11 is provided on the outer periphery of the operating rod 8 between the operating plate 10 and the lattice plate 7, and the pressure release valve 9 is constantly urged by the spring spring 11 to keep the outer peripheral edge of the pressure releasing port 6.
6a is pressed to close the pressure release port 6. Short-circuit bars 12 and 12 'are provided on both sides of the operating plate 10, and short-circuit contact pieces 13 are projectingly provided so as to face the short-circuit bar 12 from the conductors 4 of the three phases and three phases on the power source side, respectively. Side short-circuit contact piece 1 so as to face the short-circuit bar 12 'from the conductors 4'of each of the three phases.
3'is protruding.

In the case of this embodiment, the opening and closing of the switch is performed by the above-mentioned switching contact mechanism section
Conductors 4 and 4'are brought into contact with each other or separated from each other. Then, as shown in FIG. 3, a short circuit occurs in the switch body 1 and the arc 1
When 4 occurs, the internal pressure in the switch body 1 rises, and when this internal pressure exceeds a predetermined constant value, the pressure release valve 9 is pushed against the force of the spring spring 11 and the operating punch 8 is pushed to the switch body 1 Sliding outwardly, the pressure release valve 9 separates from the outer peripheral edge 6a of the pressure release port 6 and projects outward, and the pressure release port 6 is opened. As a result, the high temperature gas in the switch body 1 is discharged to the outside from the pressure release port 6 through the large number of through holes of the lattice plate 7. At the same time, the actuating plate 10 provided at the inner end of the actuating pestle 8 also moves, and the short-circuit bars 12, 12 'on both sides
Respectively contact the short-circuit contact piece 13 of each phase of the three phases on the power supply side or the short-circuit contact piece 13 'of each phase of the three phases on the load side. As a result, a phase short circuit occurs on the power supply side or the load side, the arc short circuit shifts to a metal short circuit, and the arc 14 is extinguished. Then, the internal pressure in the switch body 1 drops.

Once the short-circuit contact piece 13 or 13 'and the short-circuit bar 12 or 12' are brought into contact with each other, the short-circuit contact piece 13 or 13 'is locked by a force such as a spring or a magnetic force of the lock mechanism, so that the contact is maintained. On the other hand, the breaker of the substation detects the ground fault current due to the short circuit accident of the switch and opens it after a certain time. The operator then repairs or replaces the switch.

(Effects of the Invention) In the present invention, when a short-circuit accident occurs in the switch, the short-circuit bar is brought into contact with each of the short-circuit contact pieces on the power supply side and the load side by interlocking with the opening operation of the pressure-release port of the pressure-release valve due to an increase in internal pressure. The short-circuit bar and the short-circuit contact pieces are locked in a contact state. As a result, the arc short circuit is transferred to the metal short circuit and the arc energy is quickly extinguished. Therefore, it is possible to prevent the explosion of the high temperature gas due to the occurrence of the arc, and to prevent the danger to the passersby etc. due to the damage of the equipment inside the switch body and the large discharge of the high temperature gas to the outside of the switch body.

Also, since each short-circuit bar and each short-circuit contact piece are locked in contact with each other, even if the breaker on the power supply side is turned on and retransmitted, the relevant switch is still in phase short circuit, so it is easy to find an accident. is there.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is a sectional view of the present invention, and FIG. 2 is an explanatory view showing the relationship between the three-phase short-circuit contact piece and the short-circuit bar of the present invention in the state of FIG. FIG. 3 is a sectional view showing an operating state of the present invention when a short-circuit arc occurs, and FIG. 4 is an explanatory view showing a relationship between the three-phase short-circuit contact piece and the short-circuit bar of the present invention in the state of FIG. . In the figure, 1 is a switch body, 2 is a bushing, 4 and 4'are conductors, 6 is a pressure release port, 8 is an operating punch, 9 is a pressure release valve, 10 is an operating plate, 1
1 is a spring spring, 12 and 12 'are short-circuit bars, and 13 and 13' are short-circuit contact pieces.

Claims (1)

[Claims] 1. A power source side in a closed switch which is provided with a normally closed pressure release valve which uses air or insulating gas as an insulating and extinguishing medium and which opens a pressure release port by an internal pressure of a certain value or more. And a short-circuit contact piece is provided from each of the conductors that lead to the three-phase electrodes on the load side, one short-circuit bar that can be freely contacted with the three-phase short-circuit contact piece on the power supply side, and the three-phase short-circuit contact piece on the load side. The other short-circuit bar that can be freely contacted is provided, and each of these short-circuit bars is supported by an operating plate, and this operating plate and the above-mentioned pressure release valve are integrally connected by an operating pestle. Each short-circuit bar is separated from each short-circuit contact piece when the pressure relief valve is closed, and each short-circuit bar contacts each short-circuit contact piece when the pressure relief valve is opened. Is equipped with a locking mechanism that locks each short-circuit contact piece when it comes into contact with it. Switch to.