JPS5963623A - Breaking device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power cutoff device, and particularly to a power cutoff device in which a buffer type cutoff portion and a vacuum cutoff portion are connected in series.

The problem of short-circuits in power systems continues to increase as demand for electricity increases and supply sources become more concentrated and unevenly distributed, and plans are being made for UHV power transmission and DC power transmission with a rated voltage of 1000 kV. Accordingly, the responsibility placed on a good power circuit breaker is to increase the breaking capacity and increase the voltage. In recent years, buffer-type gas circuit breakers filled with 3 1+ gas, which has excellent insulation and arc-extinguishing properties, have become mainstream as high-voltage, large-capacity circuit breakers. Due to its quick arc-extinguishing properties, the breaking capacity per unit is 300 kV.
It has reached 50kA, and the combination of this unit has reached 50kA.
50kV63kA 2-point cut, 1100kV63kA 4
Point cutting is also possible.

However, the interruption resistance of a buffer type gas breaker is affected by the rate of change in current at the zero point of the flow (di/dt) and the rate of rise in the restart voltage immediately after current interruption (dv/dt).Currently, di/dt is 30~40A/, c+
s, dv/di of 10 to 15 and ■/μs is considered to be the maximum per unit, and depending on the combination,
The limits of performance appear below these values. In particular, when used for DC cutoff, di/dt
It is assumed that dv/dt may exceed 50A/μS, and if dv/dt is large, there is a high probability that the new year will be a success if thermal breakdown occurs at a voltage of several kV to several tens of kV or less within a few microseconds after the current is cut off. , the limit of the thermal breakdown characteristics is determined by this thermal breakdown.

In order to improve this thermal breakdown characteristic, in buffer type gas breaker, a capacitor is inserted in parallel in the breaker part to
/dt is often made gentler. However, inserting a capacitor in parallel to the breaker
In terms of insulation reliability, ゛ is a negative value compared to thick 1, so if a capacitor is installed, the capacitance should be as small as possible (for example, to improve the voltage division ratio in a multi-point circuit breaker). capacity) is desired.

On the other hand, vacuum breakers have high di/dt and dv/dt
50A/μS Karama 2L has a performance that can withstand
It is said that it can withstand a di/dt of 50 to 20 OA/μS, and even a dv/rlt of 5 to 1°kV/μS. However, with current vacuum breaker technology, the occurrence of restriking cannot be avoided due to structural reasons, so it is considered a turning point to develop an ultra-high pressure vacuum breaker.

Therefore, a buffer type gas breaker and a high d i/d
A breaker has been proposed in which a vacuum breaker exhibiting sufficient insulation recovery characteristics with respect to t is connected in series to take advantage of the characteristics of each. An example of this is shown in FIG.

This breaker has two containers 2 and 3 that are airtightly partitioned by an insulating spacer 1, with a nozzle-type breaker 4 in one container 2 and a vacuum breaker 5 in the other container 3. It is installed. The buffer type breaker 4 is composed of a fixed contact 6, a movable contact 7, a buffer cylinder 8, an insulating nozzle 9, a piston 10, a piston support fitting 11, etc. The piston support fitting 11 is an insulating support. 12 and is connected to the center conductor 13 of the bushing. The movable contactor 7 is operated from the outside via an insulated operating rod 14, a lever 15, etc. , the vacuum interrupter 5 includes a fixed contact 16, a movable contact 1T, and a vacuum container 1.
It consists of 8th grade. The vacuum container 18 is composed of an insulating cylinder 19, a fixed contact side terminal 20, a movable contact side terminal 21, a bellows 22, and the like. The bellows 22 is attached so as to protrude inside the vacuum container 18.

The movable contact (1)ll terminal 21 is supported by an insulating support 23 and connected to the center conductor 24 of the bushing.

The movable contactor 17 is operated from the outside via an insulated operating rod 25 and a reno 26.

The buffer type breaker 4 and the vacuum breaker 5 are connected in series so that the fixed contacts 6 and 16 of each are directly connected.1, each container 2.3 is filled with SF6 gas. The gas pressure inside container 3 is lower than that inside container 2. This is to protect the bellows 22 of the vacuum breaker 5. In this breaker, the initial part of the recovery voltage after current interruption is set such that the vacuum breaker 5 makes most of the voltage negative, and the buffer type breaker 4 bears the voltage increase after that. For this reason, a nonlinear resistor 27 is connected in parallel to the vacuum breaker 5, and a capacitor 28 is connected in parallel to the buffer type breaker 4. In order to prevent the insulating spacer 1 from being damaged by the emitted high-temperature gas, a guide 29 made of an insulator is provided around the fixed contact 6 of the buffer type breaker 4.

If configured as in 1.1, high di/dt and dv
However, in the above-mentioned breaker, when the breaker is in the closed state, the contact parts of the buffer-type breaker and the vacuum breaker If part are The energizing current will flow through the
Since the contact area of this contact portion cannot be increased, the current level is limited to about 3000 A at most. Therefore, the 5-pin current carrying current is 4000. A and 8000
A. If the current is further 1200 OA, it is conceivable to separately provide current-carrying contacts in each of the buffer type breaker and the vacuum breaker. However, since the buffer type breaker has a short stroke, and the contacts are in contact with each other by butt, the contact of the vacuum breaker (arc-extinguishing Providing current-carrying contacts that need to be opened in advance of the ruptures described above has the disadvantage of making the structure extremely complicated.Therefore, in the case of □It was considered difficult to do so.

Furthermore, recently, a structure in which a buffer type breaker and a vacuum breaker are connected in series, each provided with an energizing contact, has been proposed. An example is shown in FIG. This breaker also includes an insulating spacer 1, a container 2 on the high gas pressure side, a container 3 on the low gas pressure side, a buffer type breaker 4, and a vacuum breaker 5. In this device, the fixed contacts 6.16 of the buffer type breaker 4 and the vacuum breaker 5 are placed on the outside.
The movable contacts 7, 17 are respectively arranged on the inside, and an insulated operating rod 30 for operating the two movable contact ears 17 is arranged in the central part. In other words, the arrangement is reversed from that in FIG.

A fixed side energizing contact 31 is provided on the fixed contact 6 side of the buffer type breaker 4, and a movable side energizing contact 32 is provided on the buffer cylinder 8. Further, a fixed 9111 energizing contact 33 is provided on the fixed contact 16 side of the vacuum breaker 5, and a movable energizing contact 34 is provided on the movable contact 17 side.
are provided for each. The movable current-carrying contact 34 on the side of the vacuum breaker 5 has a stroke thicker than the movable contact 17 of the vacuum breaker 5, and has a stroke that is larger than that of the movable contact 17 of the vacuum breaker 5, and is designed to open faster than the vacuum breaker 5. It is designed to be driven by the wipe device 35. Therefore, in this breaker, when in the closed state, the bushing center conductor 13 - the support metal fitting 36 - the fixed side current-carrying contact 31 -
Movable side energizing contact 32 - Puff cylinder 8 - Slide contact 37 - Intermediate structure 38 - Slide contact 39 - Movable side energizing contact 34 - Fixed side energizing contact 33 - Support fitting 4 - Bushing center conductor 24 Most of the current flows through the path K.

In this way, in the breaker shown in FIG. 2, the STB current flows through the energizing contacts, which have a larger contact area than the contacts in the buffer type breaker and the vacuum breaker. be able to.

However, in the above-mentioned breaker, it is necessary to provide a wipe device on the vacuum breaker side to adjust the stroke between the movable contact of the vacuum breaker and the movable 1i1+ energizing contact, which reduces the number of parts. Many of them have the disadvantage of being cumbersome in structure and large in size. Further, the fact that there are two contact portions of the current-carrying contact that may become a heat source due to poor contact also causes a decrease in reliability.

SUMMARY OF THE INVENTION An object of the present invention is to provide a breaker device that overcomes the drawbacks of the prior art described above, has a simple structure, is highly reliable, and can carry a large current.

In order to achieve this object, the present invention provides a breaker device in which a buffer type breaker and a vacuum breaker are connected in series so that their fixed contact sides are directly connected. A fixed-side energizing contact extending through the outer periphery of the true wall breaker and extending to the buffer-type breaker is attached to the side terminal, and comes into contact with the fixed-side energizing contact when the buffer cylinder of the buffer-type breaker is in the inserted state. It is characterized by the provision of a movable side energizing contact.

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIG.

In this breaker device, a buffer type breaker 4 and a vacuum breaker 1 part 5 are housed in one container 41, and the container 41 is filled with SF6 dregs. Buffer type breaker 4
The vacuum cutoff section 5 and the vacuum cutoff section 5 are connected in series so that the respective solid W contacts 6 and 16 are directly connected, similar to the one shown in FIG.

A fixed-side energizing contact 42 extending through the outer periphery of the vacuum breaker 5 to the buffer type breaker 4 is attached to the movable contact thin J terminal 21 of the vacuum breaker 5 . This fixed side energizing contact 42 has a cylindrical shape, and has a shape in which the vacuum breaker 5 is housed inside. On the other hand, the buffer cylinder 8 of the buffer type breaker 4 is provided with a movable energizing contact 43 that comes into contact with the fixed energizing contact 42 in the closed state. In this embodiment, the outer circumferential surface of the tip of the buffer cylinder 8 is directly connected to the movable side energizing contact 43.
However, the movable side energizing contact 43 may be provided protrudingly from the tip of the buffer cylinder 8. Also,
A bellows 22 provided between the movable part and the fixed part of the vacuum breaker 5 is provided so as to protrude to the outside of the vacuum container 18 .

The rest of the configuration is the same as that in Figure 1 except that the nonlinear resistor and capacitor are not installed.
Corresponding parts are given the same reference numerals and their explanations will be omitted.

With the above configuration, in the closed state, the center conductor 13 of one bushing - the piston support fitting 11 - the piston IO - the buffer cylinder 8 - the movable side energizing contact 43 - the fixed side energizing contact 42 - the movable contact child side) r1°
The energizing current will flow along the center conductor 24 of the M1 section 1--the other bushing.

Since the energizing contacts 42 and 43 can have a large contact area, even when the energizing current is sufficiently large in a steady state, heat generation and welding do not occur at the contact parts (a stable energizing state can be maintained). .Furthermore, the fixed side energizing contact 42
extends from the movable contact side terminal 21 of the vacuum breaker 5 to the movable side of the buffer type breaker 4 through the outer periphery of the vacuum breaker 5. Therefore, in the closed state, the contact 16 of the vacuum breaker 5 Since the contact portions 16 and 17 of the vacuum breaker portion 5 are short-circuited, the current flowing in the steady state flows through the contact portions of the current-carrying contacts 42 and 43, which have a large current carrying capacity. Even if the energizing capacity of the 17 is not sufficient, there is no risk of heat generation or melting. It is possible to use a smaller force.

This is also convenient for housing the vacuum interrupter 5 within the cylindrical fixed-side energizing contact 42. Furthermore, the shunt current also flows through the contacts 6 and 7 of the buffer-type breaker 4 and the tangential parts of the contacts 16 and 17 of the vacuum shield 1υi part 5.
However, since this portion does not generate heat even if the contact resistance is large, it is possible to freely select a material with low wear and tear as the contact that generates an arc, which is advantageous in terms of device setting d1.

The shutoff operation is performed as follows. When the cut-off operation begins, the current-carrying contacts 42 and 43 are first opened. At this time, since the contact 6.7 of the buffer-type breaker 4 and the contact 16.17 of the vacuum breaker maintain their contact state, an arc occurs when the current-carrying contact 42.4i opens ν1. There's nothing to do. Next, the contacts 6 and 7 of the buffer-type breaker 4 are opened, and then the two contacts 6. The separation distance of γ becomes sufficiently large, and the pressure inside the buffer cylinder 8 becomes sufficiently high, so that the dielectric strength between the contacts 6 and 1 immediately after the current is interrupted can withstand the voltage applied to all points of the breaker. Once reached, the contact 16.1 of the vacuum interrupter 5
7 is released. By doing this, immediately after the current with a large di/dt is interrupted, the transient recovery voltage is applied to both the buffer type breaker and the vacuum breaker, but the di/dt
Due to its thermal history, the recovery of the insulation 1iIIF between the electrodes of the buffer-type breaker is insufficient after the first period in which a large current is interrupted (the impedance is in a low state.On the other hand, the vacuum breaker has a buffer-type Since the speed of insulation recovery is faster than that of the spear 1 part, the impedance between the poles becomes thicker. Therefore, immediately after the current is interrupted, especially for a period of about 0 to 10 μs, the transient recovery voltage is low due to the impedance relationship. It will be applied to the vacuum breaker.Also, the partial pressure to the buffer type breaker side is large (if thermal breakdown is about to occur, the impedance on the buffer type breaker side will drop rapidly, so the voltage sharing will be The vacuum breaker side automatically becomes thicker (becomes thicker).The dielectric strength of the buffer type breaker recovers significantly after passing through the performance-determining region due to thermal breakdown, so even if dielectric breakdown occurs on the vacuum breaker side, , the buffer type breaker will not lead to dielectric breakdown.

In addition, in the above-mentioned new shield, the buffer type cutoff part and the vacuum cutoff part are housed in the same container, so the gas pressure around the vacuum cutoff part is the same as that of the buffer type cutoff part, and the bellows 1.1: A larger gas pressure is applied to the bellows than in the case of the first bellows, but since this bellows is installed so as to protrude to the outside of the vacuum container as described above, ), it is in a compressed state, that is, in a state where its strength against gas pressure is high, so it can be supported under high gas pressure.

In addition, compared to the two-component type, the current-carrying contact has only one contact portion, so there is no risk of malfunctions due to poor contact, and high reliability can be achieved. In addition, the current-carrying contact short-circuits both the buffer-type breaker and the vacuum breaker at once, and is opened and closed by the movement of the buffer cylinder. This eliminates the need for a wiping device, which reduces the number of parts, simplifies the structure, and downsizes the structure, which not only reduces costs (but also improves reliability from this point of view).

FIG. 4 shows another embodiment of the invention. In this cause,
The same or equivalent parts as in FIG. 3 are given the same reference numerals.

This embodiment differs from the one shown in FIG. 3 in that a capacitor 28 is connected in parallel to the buffer type breaker 4, and a nonlinear resistor 27 is connected in parallel to the vacuum breaker 5.

The capacitor 28 is constructed by cutting out a part of the fixed side energizing contact 42 and connecting the fixed contact side terminal 20 of the vacuum breaker 5 (which is also the fixed contact side terminal of the buffer type breaker 4) and the buffer type breaker 4. The n1 non-linear resistor 21 is inserted between the fixed contact side terminal 20 of the vacuum breaker 5 and the fixed side energizing contact 42. The non-linear resistor 27 is particularly preferably one whose main component is zinc oxide. Since the interelectrode voltage of the vacuum breaker is low (from several kV to several tens of kV), the nonlinear resistance 2
7 is small (and can be placed inside the fixed-side current-carrying contact 42).

According to this embodiment, most of the initial part of the transient recovery voltage of the current interrupt is applied to the vacuum interrupt by the capacitor 28 inserted in parallel with the buffer type interrupt. On the other hand, the recovery voltage increases,
Once the voltage limit of the non-linear resistor 27 is exceeded, all higher voltages will be applied to the buffer type breaker.

Therefore, there is an advantage that the current carrying capacity can be increased by fully utilizing the characteristics of the vacuum breaker and the buffer type breaker.

As explained above, according to the present invention, in a breaker device in which a buffer-type breaker and a vacuum breaker are connected in series, a current-carrying contact is provided that short-circuits both breaker parts at once, so that the current-carrying capacity can be reduced. In addition to being able to increase the size, the current-carrying contact has only one contact portion and does not require a wiping device, which has the advantage that the structure is simple and compact, and reliability is improved.

[Brief explanation of the drawing]

1 and 2 are longitudinal sectional views, respectively, showing a conventional breaker, and FIGS. 3 and 4 are longitudinal sectional views, respectively, showing a breaker according to an embodiment of the present invention. 4... Buffer type breaker, 5... Vacuum breaker, 6... Fixed contact, 7... Group movable contact, 8... Buffer cylinder, 16...
Group/Fixed contact, 17...Movable contact, 18.
...Vacuum container, 21.Old...Movable contact side terminal, 22.Old...Bellows, 27.....Nonlinear resistance, 28.....Capacitor, 41. Old container, 4
2...Fixed side energizing contact, 43...Curved/possible i
Contact for side energization.

Claims (1)

[Claims] 1. A buffer-type breaker and a vacuum breaker are connected in series with their fixed contact sides facing directly, and a movable contact hand of the vacuum breaker is provided. A fixed-side energizing contact extending through the outer periphery of the vacuum breaker to the para-border-type breaker is attached to the side terminal, and when the fixed-side energizing contact is inserted into the panzer cylinder of the buffer-type breaker, the fixed-side energizing contact A movable side current-carrying contact is provided. Sha rupture ■゛, characterized by. 2. In the 104th range of %π'tN, the breaker device is characterized in that the stationary side energizing contact is a cylindrical body that accommodates the vacuum shield m1 inside. 3. Claims In scope 1 or 2, the vacuum breaker is housed in the same gas pressure vessel as the buffer type breaker, and the bellows provided between the movable part and the identification part of the vacuum breaker is housed in the vacuum vessel. A breaker, characterized in that the breaker is mounted so as to protrude from the vacuum breaker. 4. Claims @ 1 In any one of the first to third claims, the fixed contact of the vacuum breaker A breaker device characterized in that a non-linear resistance is connected between the side terminal and the fixed side energizing contact.
□ In the breaker, a non-linear resistance is connected between the fixed contact side terminal of the vacuum breaker part and the fixed side energizing contact, and a capacitor is connected in parallel with the pack-a-type breaker part. Device~.