JP2523905B2 - Switch - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a switch, and more particularly to a switch suitable for a pole switch used in a power distribution system.

[Conventional technology]

As a switch for a pole used in a conventional power distribution system, for example, as described in Japanese Patent Laid-Open No. 61-99226, a pair of three-phase switches on both sides on the same horizontal axis of a container are used. Each bushing is attached, and between the pair of bushings in the container, there are provided three phases of disconnection parts configured in the insulating mold so as to open and close on the above-mentioned horizontal line. It is known to use a contact type contact for electrical connection between a pair of bushings.

[Problems to be Solved by the Invention]

As described above, the conventional pole switch has a configuration in which the blocking portion is arranged between the pair of horizontally arranged bushings so as to be opened and closed in the coaxial direction. Therefore, the pole switch is long in the axial direction of the bushings. I'm running. For this reason, the support structure must be solid, which is not desirable as a pole switch placed on a power pole.

An object of the present invention is to provide a switch which can reduce the outer dimensions.

[Means for solving the problem]

The present invention, in order to achieve the above object, a case,
A pair of bushings provided facing the case, a circuit breaker disposed in the case between the pair of bushings and having a pair of separable contacts, and a case breaker for driving the circuit breaker. One end is connected to the provided operating device and the end of the circuit breaker, and the other end is bent and extended in opposite directions along the direction perpendicular to the opening and closing direction of the contactor of the circuit breaker to form the bushing. And a connected conductor.

[Action]

According to the switch of the present invention, since the opening / closing axis of the breaker is changed, the dimension of the bushing in the switch can be shortened. As a result, the switch can be downsized.

〔Example〕

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a vertical sectional front view of a switch according to an embodiment of the present invention, in which a case 1 is supported by a power distribution pole. A blocking unit 10 is formed in the case 1. The case 1 comprises a main body 1a and a bottom plate 1b, and the bottom plate 1b is attached to the main body 1a in a watertight manner. A pair of bushings 5a and 5b are attached to the main body 1a on substantially the same horizontal axis. This pair of bushings 5
In a vertical direction that is substantially orthogonal to the horizontal line connecting a and 5b, a blocking unit 10, which will be described in detail later, is arranged so as to open and close in that direction. Both terminals of the breaker 10 are insulated spacers 3a, 3
Embedded in b. The both terminals are connected to one ends of the insulated cables 4a and 4b for electric power, respectively. The other ends of the insulated cables 4a and 4b are bent, and the breaker 1
It is extended in the opposite direction so as to be orthogonal to the opening / closing operation direction of 0 and is connected to the bushings 5a and 5b. Therefore, the size of the case 1 in the height direction can be reduced so as to contact the insulated cables 4a and 4b. When a conductor is used instead of this insulated cable, it is necessary to raise the case 1 in order to secure the insulation distance.

Both ends of the blocking portion 10 are supported by the case 1 via fixed supports 9a and 9b, respectively. As a result, the blocking unit 10
Is held at the position shown in the figure and has a supporting strength against an electromagnetic force described later. The fixed support 9a is located on the opposite side of the bushing 5a electrically connected to the terminal at the same side end of the breaker 10, and is formed substantially parallel to the bushing 5a.
An electromagnetic force Fa generated by the arrangement of the cutoff portion 10, the insulated cable 4a, and the bushing 5a is received in the compression direction. Further, the fixed support 9b is located on the opposite side of the bushing 5b electrically connected to the terminal at the same side end of the breaking portion 10 and is formed substantially parallel to the bushing 5b, and the breaking portion 10 and the insulated cable 4b.
Force Fb generated by the positional relationship between the
Is received in the compression direction.

The current transformer 7 that surrounds the insulated cable 4a is formed by utilizing the space inside the case 1 that exists on the side of the breaker 10 inside the case 1.
As can be seen from FIG. 2, the zero-phase current transformer 6 surrounding the insulated cables 4a for three phases is arranged, and the zero-phase transformer 8 having one end connected to the bushing 5b is arranged. All of these are fixed to the insulating hermetic container 2 of the blocking section 10.

The current transformer 7 described above is used to open the circuit breaker by detecting an overcurrent generated when a short circuit accident occurs. The zero-phase current transformer 6 has a role of detecting a zero-phase current in the event of a ground fault on the load side and opening the circuit breaker 10 via the ground fault protection relay. The zero-phase transformer 8 detects the zero-phase voltage at the time of a ground fault,
It has the role of determining the direction of the ground fault from the phase with the zero-phase current via the directional ground fault relay, and opening and closing the circuit breaker 10 in the case of a load side accident.

As shown in FIG. 5, the shutoff unit 10 includes a common hermetically sealed container 2 in which SF ₆ gas or the like is enclosed. The hermetically sealed container 2 plays a role of suppressing the adverse effect of the arc of the peripheral equipment. An insulating nozzle 12, which will be described in detail later, is integrally formed and housed in the hermetic container 2 for three phases. A plan view of an insulating spacer 3a for sealing both ends of the common hermetic container 2 is shown in FIG. 6. As shown in the drawing, a plurality of holes 11 for mounting bolts to the hermetic container 2 are provided in the periphery, and a central portion is provided. Insulated cables 4a for three phases are embedded in. The insulated cable 4a includes an insulating coating 26 and a center conductor 25.

FIG. 5 shows the breaker 10 for one phase, in which the fixed contact 13 is connected to the central conductor 25 of the insulated cable 4b, while
The movable contact 14 is connected to the central conductor 25 of the insulated cable 4a via a spray piston 17, a current collector 18, and a spray cylinder 16. Self-extinguishing chamber 2 at the contact part of both contacts 13, 14.
The insulating nozzle 12 forming 0 is slidable by the first throat portion 22 slidably closed in the center by the movable contactor 14 and the suction piston 15 connected to the movable contactor 14. It has the 2nd throat part 23 closed up to. The second throat portion 23 forms a suction cylinder with respect to the suction piston 15, and the suction device constituted by both of them forms a movable contactor.
It has a suction chamber 21a whose volume is increased by the opening / closing operation of 14 to generate a negative pressure. The spray cylinder 16 and the spray piston 17 constitute a spray buffer device having a spray buffer chamber 21b. Further, the self-extinguishing chamber 20 formed up to the first throat portion 22 of the insulating nozzle 12 and the movable contact 14 constitutes a main part of the thermal buffer device. An electrically operated operating lever 24 is connected to the spray cylinder 16 connected to the movable contactor 14. The operating lever 24 is connected to an operating main shaft 27 as shown in FIG. One end of the operation main shaft 27 is connected to an operation mechanism 29, and the other end is led out of the case 1 and a status display needle 28 is attached. Thereby, the state of the shutoff unit 10 can be determined from the state display hand 28.

The configuration of the operating mechanism 29 described above will be described with reference to FIGS. 2 and 3, the operation main shaft 27 is connected to a lever 42 via a lever 40 and a link 41. A closing side lever 44 is attached to the shaft 43 of the lever 42. An elongated hole 45 is provided on one side of the closing-side lever 44. The pin 46 and the plunger 47 engaged with the slot 45
And are linked by a link 48. The plunger 47 is pulled down by the excitation of the excitation coil 49 against the reset spring 50 in the drawing shown in FIG. Also,
A spring 51 for opening the blocking portion 10 is connected to the other side of the closing lever 44 described above. When the plunger 47 is attracted by the exciting coil 49, the lever 40, the link 41, the lever
The operation main shaft 27 is rotated by 42 and the closing side lever 44
Thereby, the spring 51 is stretched. Fig. 4 shows the operating mechanism 29
This shows a mechanism for holding the opening of the breaking portion 10 by means of the lever. This mechanism holds the extension of the spring 5 and the lever side hook 53 and the plunger side hook provided on the operating force transmission lever 52 provided on the shaft 43 of the lever 42. A latch portion 55 constituted by 54, an opening plunger 56 connected to the plunger side hook 54 for opening the latch portion 55, and an opening coil 57 thereof. By energizing the opening coil 57 and attracting the opening plunger 56, the lever side hook 53 rotates and the engagement of the latch portion 55 is released.

Next, the operation of one embodiment of the above-mentioned switch of the present invention will be described.

FIG. 7 shows the circuit breaker 10 constituting the switch of the present invention in a closed state, and in this state, the operating mechanism 29 shown in FIG.
When the opening coil 57 is excited, the opening plunger 56 is attracted and the operating main shaft 27 is rotated via the lever 40, the link 41, and the lever 42. When the operation lever 24 is rotated counterclockwise in FIG. 7 by the rotation of the operation main shaft 27, an arc A is generated as the movable contact 14 and the fixed contact 13 are separated as shown in FIG. Due to the energy of the arc A, the gas pressure in the self-extinguishing chamber 20 is increased, while the suction chamber 21a generates a negative pressure as the volume increases. During this operation, the volume of the spray buffer chamber 21b is reduced as the spray cylinder 16 moves to the left.
Since the slit 31 is formed at 6, the gas pressure in the spray buffer chamber 21b does not increase. When the shut-off operation further proceeds, the movable contactor 14 passes through the first throat portion 22 as shown in FIG. 9, so that the gas in the self-extinguishing chamber 20 whose pressure is increased by the arc 40 becomes a negative pressure and becomes a suction chamber. It forms a gas stream flowing into 21a. When the large current is cut off, the pressure increase in the self-extinguishing chamber 20 due to the arc A causes a sufficient spraying, whereby the current is cut off, and when the small current is cut off, the self-extinguishing chamber 20 is pressed. However, due to the negative pressure in the suction chamber 21a, the self-extinguishing chamber 20
A gas flow from the is formed and good blocking performance is obtained.
However, for the interruption of the current in the intermediate region, the self-extinguishing chamber 20
It is not possible to expect a sufficient increase in pressure in the suction chamber 21a, and the pressure rises in the suction chamber 21a due to the gas that has flowed in before the extinction of arc is completed, and effective spraying cannot continue. Although it can be seen in the container, the interruption part of this embodiment is also improved in this respect. That is, as shown in FIG. 9, at the end of the suction operation in which the negative pressure of the suction chamber 21a is impaired, the slit 31 of the spray cylinder 16 passes the spray piston 17 and the gas in the spray buffer chamber 21b is compressed, and the movable contact A gas flow that acts on the arc A is formed through the hollow portion 19 of the child 14, and the arc is extinguished by this gas flow. In this way,
A switch having stable breaking performance from a small current region to a large current region can be obtained.

FIG. 10 is a circuit diagram of the power distribution system. The circuit breaker 32a provided in the substation 35a is a trip coil via a fault detection relay 37 and a cooperation timer 38 when a fault current is detected by the current transformer 36. Give a command to 39 to perform the shutoff operation.
A plurality of pole-mounted switches 33a, 33b, 33c are connected to the distribution system between the substation 35a and the substation 35b.

FIG. 11 is a time chart explaining an example of a ground fault accident section locating system.

Now, in the distribution system of FIG. 10, a ground fault accident 34 occurs at time t _1.
Of the current transformer 36a of the circuit breaker 32a of the substation 35a.
Detects this, and the accident detection relay 37 operates at time t ₂ ,
The cooperation timer 38 delays the time from t ₂ to t ₃ by about 3 seconds, and at time t ₃ , the trip coil 39 is excited to break the circuit breaker 32.
At a time t ₄ , a circuit is opened, and at time t ₅ , the circuit is shut off. Therefore, the current caused by the ground fault accident 34 is cut off, and then at time t ₆
Opens the switch 33b. In this way, the switch has 3
It is necessary to consider the influence of electromagnetic force due to the flow of the ground fault current of about a second. As described above, since the switch has the structure shown in FIG. 1, it has sufficient strength against this electromagnetic force. That is, as shown in the figure, when the vertical length of the insulated cable 4b is L and the magnetic field due to the ground fault current i is B, the electromagnetic force F generated is F = BiL (1) It occurs in the arrow direction. However, since the fixed supports 9a and 9b are provided in the same direction, the electromagnetic force as the compressive force can be easily received by the fixed supports 9a and 9b.

After the above-described interruption operation, when sequentially introduced in the order of the circuit breaker 32a, switches 33a, 33b, the previous accidents continues, as Figure 12, switch 33b fault current at time t ₇ with introduction of At 34, the current transformer 36 detects again and the accident detection relay 37 is activated. Then, according to the control system of the system, the switch 33
A cutoff command is immediately given to b, and the short-circuit current is cut off at time t ₈ . At this time, the switch 33b is the breaking unit 1 shown in FIG.
An operation of 0 shows good breaking performance.

As can be seen from the above description, the switch shown in FIG.
It has sufficient strength against an electromagnetic force due to a short circuit current of about 3 seconds and has a short circuit current interruption capability.

FIG. 13 is a vertical sectional front view showing a switch according to another embodiment of the present invention, and the same components as those in FIG. 1 are designated by the same reference numerals. In this figure, the symbol P indicates a utility pole. In this embodiment, the opening / closing direction of the shutoff unit 10 is horizontal, and the pair of bushings 5a, 5b are pulled out in a substantially vertical direction. Therefore, the directions of the electromagnetic forces Fa and Fb due to the short circuit current i,
Since it coincides with the gravity direction of the blocking portion 10, the fixed supports 9a and 9b can be made simpler than in the case of FIG. Although one end of each of the fixed supports 9a and 9b is fixed to the sealed container 2 made of an insulating material of the breaking portion 10 in any of the embodiments, it is fixed to the other portion of the breaking portion if it is electrically insulated. You may fix it.

Although the current transformers 6 and 7 are fixed to the container of the shutoff portion 10 in the above-described embodiment, they may be provided at the bushing portion in the case 1.

As described above, in the embodiment of the present invention, since the shutoff portion that opens and closes in the direction substantially orthogonal to the drawing direction by bushing is provided, the switch can be downsized, its supporting structure can be simplified, and the appearance can be improved. The above is also effective. In addition to supporting both ends in the axial direction of the blocking section with fixed supports,
Since the fixed supporting portion receives the electromagnetic force, it is possible to easily obtain the switch which is strong against the electromagnetic force while shortening in the pulling-out direction of the bushing.

Further, in the present invention, since the blowing buffer device for compressing the blowing gas at the end of the operation of the blowing device is added, it is possible to obtain a stable blowing action from a small current region to a large current region and obtain a stable interruption performance. it can.

〔The invention's effect〕

According to the present invention, since the shutoff portion is arranged in the case so that the opening / closing operation shaft is provided in the direction substantially orthogonal to the drawing direction by bushing, the dimension of the case in the bushing drawing direction can be shortened. As a result, the switch can be downsized.

[Brief description of drawings]

FIG. 1 is a vertical sectional front view of an embodiment of a switch according to the present invention,
1 is a sectional view taken along the line II-II in FIG. 1, and FIG. 3 is a sectional view taken along the line III-III in FIG. 2, showing the configuration of the operating device.
FIG. 4 is a front view showing a closing and holding mechanism of an operating device used in the present invention, and FIG. 5 is a vertical cross-sectional front view showing in an enlarged manner a breaking part used in the switch of the present invention shown in FIG. FIG. 7 is a top view of the shutoff portion shown in FIG. 5, FIGS. 7 to 9 show the operation of the shutoff portion, FIG. 7 shows the closed state, and FIG. 8 shows the initial state of opening the open circuit. , FIG. 9 shows the state in the latter half of the open circuit. FIG. 10 is a circuit diagram of a power distribution system including an embodiment of a switch according to the present invention, and FIGS. 11 and 12 are time charts of respective devices of the power distribution system shown in FIG. 10 by a short-circuit fault location system. FIG. 13 is a vertical sectional front view showing another embodiment of the switch of the present invention. 1 ... Case, 2 ... Insulated container, 3a, 3b ... Insulation spacer, 4a, 4b ... Insulated cable, 5a, 5b ... Bushing, 6,8 ... Zero-phase current transformer, 7 ... Ventilator, 9a, 9b ... Fixed support, 10 ... Breaking part.

Claims (1)

(57) [Claims] 1. In a switch connected to a distribution line, a case, a pair of bushings provided so as to face the case, and arranged in the case so as to be substantially orthogonal to a line connecting the pair of bushings. A breaking unit having a pair of separable contacts, a breaking unit operating mechanism provided in the case to drive the breaking unit, and one end connected to each end of the breaking unit. A switch comprising: an insulating cable having its ends bent and extending in opposite directions along a direction perpendicular to the contact opening direction of the breaking unit and connected to the bushing.