JP2670279B2 - Breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial application field) The present invention relates to a circuit breaker having a large capacity and a reduced number of series breaking points.

(Prior Art) Conventionally, a gas circuit breaker of 500 KV or more, which is required to suppress the closing overvoltage to a low level, has at least two break points in series, so the insulation recovery characteristic of the closing resistance contact that is installed in parallel with this is generally used. There was enough margin.

However, in recent years, in gas circuit breakers with rated voltage of 420KV and 550KV class, the number of series contacts has been further reduced, and one-point break has appeared in the same rated voltage class. When the number of series breaking points in this class becomes 1 point, the closing resistance switching contact connected in parallel with this breaking section also becomes 1 point, making it difficult to restore the insulation prior to the breaking section when the contact is opened. Come on.

(Problems to be solved by the invention) A high-voltage (420KV, 550KV) class single-break circuit breaker accelerates the insulation recovery speed between its poles, so that the fixed side of the breaker moves forward as well as the movable side. It is effective to retreat and accelerate the opening speed between the poles.

In the circuit breaker having such a structure, it becomes difficult to obtain a characteristic that the interelectrode insulation recovery speed of the closing resistance switching contact mounted in parallel with the circuit breaker is sufficiently higher than the insulation recovery speed of the main circuit breaker that is the current circuit breaker. The main breaking part side cannot be surely cut off, and there is a possibility of ignition on the closing contact side.

The purpose of the present invention is to make the insulation recovery characteristic of the closing resistance contact at the time of opening sufficiently earlier than that of the main breaking portion to surely perform the current interruption at the main breaking portion, and at the same time, at the time of closing, which is the purpose of the closing resistance contact. It is intended to provide a circuit breaker that can be reliably executed in consideration of the characteristic to be input prior to the main breaking section.

[Structure of the Invention] (Means for Solving the Problems) The present invention is arranged in a tank filled with an insulating gas so as to face a pair of electrode portions, and both the pair of electrode portions are closed by an opening / closing operation mechanism. In the circuit breaker that moves forward together and retracts back and forth toward Hingaiji, the box housing the wipe spring is fixed to each of the pair of electrode sections moving forward or backward, and the opposite sides of the box Is always displaced in the direction of the gap by the wipe spring, the main breaking part is opened first when the main breaking part is pulled out, and the pair of closing resistance contacts that are closed before the main breaking part are closed. It is characterized by being provided facing each other.

(Operation) In the present invention, when the circuit breaker is pulled out, the closing resistance contact is opened early so that the insulation recovery speed of the closing resistance contact is sufficiently faster than that of the main breaking section. And a predetermined resistance energizing time is secured.

(Embodiment) The present invention will be described below with reference to an embodiment shown in FIG. 1 and FIG. First, in FIG. 1, a fixed-side cutoff section 2 and a movable-side cutoff section 3 are coaxially arranged inside a gas tank 1 filled with SF ₆ gas.

The fixed-side cut-off portion 2 is configured by mounting a fixed-side main conducting portion 5 on the fixed-side conducting portion 4 in a sliding contact manner, and providing a fixed electrode 6 on the fixed-side main conducting portion 5. An external lead-out terminal conductor 7 is connected to the fixed current-carrying portion 4, and two closing resistors 8a and 8b are fixed to the inner wall of the gas tank 1 via an insulator 9 as shown in the figure. One of the closing resistors 8a
Further, the rod 10 on the opposite side of the fixed electrode 6 is inserted so as to move in sliding contact with the axial movement of the fixed main energizing portion 5.

The movable-side blocking unit 3 is configured by providing a movable rod 11 with a puffer cylinder 12, and further providing a movable electrode 13 and an insulating nozzle 14 for inserting and cutting the fixed electrode 6 at the tip thereof. By moving the movable rod 11 in the axial direction as described later, the puffer cylinder 12 comes into contact with the contactor 15 and then slides the piston 16 to compress or expand the insulating gas in the puffer chamber 17.

The movable electrode 13 of the movable blocking unit 3 is axially retracted by the insulating operation rod 18 via the movable rod 11 to perform blocking and closing operations with the fixed electrode 6. The movable electrode 13 and the movable rod 11 include a contact 15 and a piston 16.
It is electrically connected to the movable-side current-carrying portion 20 via the support base 19, and the external lead-out terminal conductor 21 is led out from the movable-side current-carrying portion 20.

Further, a link mechanism 22 is provided in the movable-side energizing section 20. That is, the levers 24, 24 'are rotatably attached to the support bases 23, 23' with a pin, and one end of the levers 24, 24 'is hinged to the movable rod 11 by the levers 25, 25', and the levers 24, 24 '.
Lever 26, 26 'is provided at the other end of the. However, the tips of the insulating rods 27, 27 'connected to the levers 26, 26' of the lever mechanism 22 are connected to the stationary main energizing portion 5 of the stationary breaker 2. Therefore, the fixed-side main energization unit 5 is the movable-side energization unit 20.
Link mechanism 20 and insulating rods 27 and 2
Moved axially via 7 '.

Further, in the present invention, there is provided a resistance contact portion 28 which performs an opening / closing operation in conjunction with the fixed-side blocking portion 2 and the movable-side blocking portion 3. That is, the fixed side contact 29 is attached to the box body 31 attached to the fixed side main energizing section 5 via the insulator 30 by a wipe spring.
Provided with 32, movable contact 33 is a puffer cylinder
It is provided with a wipe spring 35 in a box body 34 provided in 12. The fixed contact 29 is connected to the closing resistor 8b by the flexible wire 36.
Terminal. FIG. 3 shows the relationship between the resistance contact section 28 and the fixed-side cutoff section 2. That is, the fixed energization part 4 and the fixed-side main energization part 5 have a cylindrical shape surrounding the closing resistor 8a, and the box 31 of the resistance contact part 18 is arranged in the notch. The fixed current-carrying part 4 is supported by the gas tank 1 with an insulator 37. The fixed-side main energization part 5 is moved in the axial direction by an insulating rod 27.

Next, the operation of the circuit breaker of the present invention thus configured will be described. In FIG. 1, when a trip command is input to an operating mechanism (not shown), the movable electrode 13 of the movable blocking section 3 is linked to the fixed electrode 6 of the fixed blocking section 2 by the movement of the operating rod 18. By the movement of the mechanism 22, each of them is moved in the backward direction to start the separating operation. In this case, in the main breaking portion, the fixed electrode 6 and the movable electrode 13 are in sliding contact with each other and slide over several tens of mm while energizing, and the main breaking portion is not separated during this.

On the other hand, in the resistance contact portion 28, the fixed contact 29 and the movable contact 33 are both wiped by the springs 32 and 35. Therefore, the spring is set to a high opening speed of the fixed side electrode 6 and the movable side electrode 13 of the main breaking portion. 32, 35 could not follow, it opened before the main cutoff, and the insulation was restored at a high speed. When the main blocking portion is separated, a sufficiently high dielectric strength is maintained. Therefore, the current is reliably cut off by the main breaker.
Then, in the final process of the breaking stroke, the fixed contact 29 and the movable contact 33 of the resistance contact portion 28 are pushed out to the interelectrode side by the respective buses 32 and 35 as shown in FIG.

On the other hand, during the closing operation, when a closing command is similarly input to the operation mechanism section that is not fixed, the main blocking sections of the fixed-side blocking section 2 and the movable-side blocking section 3 and the resistance contact section 28 cause the operating rod 18 and The closing operation is started via the link mechanism 22. In this case, since the contacts 29 and 33 of the resistance contact portion 28 are pushed out by the springs 32 and 35 as shown in FIG. 2, the contacts 29 and 33 are applied prior to the fixed side electrode 6 and the movable side electrode 13 of the main breaking portion. . The fixed electrode 6 and the movable electrode 13 of the main interrupting section are mutually turned on a predetermined time after the turning on of the resistance contact section 28.

Since the resistors 8a and 8b are closed in the system during the closing time difference between the resistance contact portion 28 and the main breaker, the overvoltage when the breaker is closed is effectively suppressed. Further, since the rod 10 on the opposite side of the fixed electrode 6 of the main breaking portion is supported by the resistor 8a during sliding, the energization amount of the resistance current and the displacement of the rod 10 and the fixed-side main conducting portion 5 can be comprehensively controlled. Can be made smaller.

[Effects of the Invention] As described above, according to the present invention, even in a circuit breaker in which the breaking capacity increases and the inter-electrode separation speed and the insulation recovery speed are very fast, the closing overvoltage is relatively simple. Can be suppressed.

[Brief description of the drawings]

1 and 2 are sectional views showing the circuit breaker of the present invention in a closed state and an external state, and FIG. 3 is an enlarged sectional view of a fixed side circuit breaker of the circuit breaker of the present invention. 2 …… Fixed side breaking part 3 …… Movable side breaking part 5 …… Fixed side main energizing part 6 …… Movable electrode 8a, 8b …… Making resistor 10 …… Rod 11 …… Movable rod 12 …… Puffer cylinder 13 ... Movable electrode 16 ... Piston 17 ... Puffer chamber 18 ... Operation rod 22 ... Link mechanism 27 ... Insulating rod 28 ... Resistive contact part 29 ... Fixed contact 33 ... Movable contact 32,35 ... Spring

Claims (1)

(57) [Claims] 1. An opening / closing operation in which a pair of electrode portions are arranged in a tank filled with an insulating gas so as to face each other, and both of the pair of electrode portions are moved forward by the opening / closing operation mechanism at the time of closing and retracted by the opening / closing operation. In the circuit breaker for carrying out the above, the box body in which the wipe spring is housed is fixed to each of the pair of advancing or retreating electrode portions, and the main breaking portion is constantly displaced in the pole direction by the wipe springs on the respective opposite sides of the box body. And a pair of closing resistance contacts that are opened prior to the main breaking portion when the main breaking portion is closed and that are closed before the main breaking portion is closed.