JPS60189130A - Composite type 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] [Field of Application of the Invention] The present invention relates to a composite type circuit breaker in which a gas circuit breaker and a vacuum circuit breaker are connected in series. Relating to a shutoff device.

[Background of the Invention] The short-circuit capacity of power systems continues to increase as demand for electricity increases and supply sources become more concentrated and unevenly distributed. Accordingly, the responsibility placed on power disconnectors is to increase the breaking capacity and increase the voltage per unit.

In recent years, buffer-type gas circuit breakers using SF6 gas, which has excellent insulation and arc-extinguishing properties, have been the mainstream of high-voltage, large-capacity circuit breakers. However, the interrupting characteristics of buffer type gas circuit breakers are significantly affected by the rate of current change near the current zero point (di/dt) and the rate of increase in transient recovery voltage (dV/di) immediately after current interruption, and the continuous current When becomes large,
Short-range line failure (SLF) is a severe problem for dv/dt.
Failure of one interruption in the form of thermal breakdown occurs due to interruption duty or interruption operation including transient recovery voltage (ITR, V)'Th of high frequency component generated due to the power side bus condition of the circuit breaker. do. This is a phenomenon called thermal breakdown, which is a phenomenon that results in failure of interruption because the insulation of the arc's thermal history immediately before the interruption of the current does not recover.

In a gas circuit breaker, the arc diameter tends to become very small in the region where the instantaneous current value is small just before the current zero point, and therefore the center temperature of the arc maintains a very high value even when the current is small. Therefore, the thermal history of the arc remains even immediately after the current zero point.

In a gas circuit breaker using SF or gas, failure to shut off due to thermal breakdown in a large current region is the limit of illumination.

On the other hand, vacuum circuit breakers have extremely excellent insulation recovery characteristics, and failure to disconnect is not due to the thermal breakdown described above, but is due to an increase in electric field strength that leads to insulation breakdown once the insulation has recovered. be. However, vacuum circuit breakers have difficulty increasing the voltage per unit, and the limit is 72 to 84 kV per point.

In creating a high-voltage, large-capacity circuit breaker, the characteristics of gas circuit breakers, whose performance is determined by thermal breakdown, and the characteristics of vacuum circuit breakers, whose performance is determined by dielectric breakdown, are mutually complementary. The use of gas circuit breakers and vacuum circuit breakers in series has been known for some time. For example, Japanese Patent Publication No. 40-6658 discloses its basic structure, and
No. 128527, JP-A-57-36733, JP-A-5
6-76128 discloses a parallel element connection technique for regulating voltage sharing when a gas circuit breaker and a vacuum circuit breaker are disconnected in series. All of these embodiments have a structure in which the arc contact part is fully energized in the closed state, and is suitable for use in small systems with a rated current of 2000 amperes, but for large currents of 4000 amperes or more. However, problems such as heat generation and welding occur at the contact portion. The ninth publication, Japanese Unexamined Patent Publication No. 57-55022, discloses an embodiment in which a gas circuit breaker and a vacuum circuit breaker are each provided with a main contact for energization.

However, in this embodiment, it is necessary to provide a wipe device on the vacuum cut-off part side to adjust the stroke between the movable contact of the vacuum cut-off part and the movable side energizing main contact, so the number of parts is large and the structure is The drawback is that it is complicated and large.

Therefore, a technique as shown in FIG. 1 has been devised (Japanese Patent Application No. 170986/1986). In this embodiment, a buffer type cutoff section 4 and a vacuum cutoff section 5 are housed in one container 41, and the container 41 is filled with SFg gas. The buffer type cutoff section 4 and the vacuum cutoff section 5 are electrically connected in series. A fixed side energizing contact 42 is attached to the movable contact side end plate 21 of the vacuum cutoff section 5 and extends through the outside of the vacuum cutoff section 5 to the 75 sofa-shaped cutoff section. These 42 fixed-side energizing contacts are cylindrical in shape, with the vacuum cutoff section 5 housed inside. On the other hand, the buffer cylinder 8 of the buffer type disconnection section 4 is provided with a movable side energizing contact 43 that comes into contact with the fixed side energizing contact 42 in the closed state. With this configuration, in the closed state, the center conductor 1 of one bushing
3-screws) 7 Support fitting 11 - Histone 10 - Buffer cylinder 8 - Movable side energizing contact 43 - Fixed side energizing contact 42 - Movable contact side terminal 21 - Electrification passes through the center conductor 24 of the other bushing A stream will flow. Since the energizing contacts 42 and 43 can have a large contact area, it is possible to maintain a stable energizing state without generating heat or welding at the contact portions even when the rated energizing current is sufficiently large.

In addition, in the closed state, the contact 16 of the vacuum cutoff section 5.
17 is short-circuited, and most of the current flows through the contact parts of the current-carrying contacts 42 and 43, so the current-carrying capacity of the contacts 16 and 17 of the vacuum cut-off part 5 is insufficient. In both cases, there is no concern about heat generation or welding, and the force for applying contact force is small, and the operating force for rational operation is small.

The shutoff operation is performed as follows. First, the current-carrying contacts 42 and 43 are opened. At this time, the contact 7.9 of the buffer type cut-off part 4 and the contact 16.17 of the vacuum cut-off part 5
Since the contact state is maintained, the current-carrying contact 42.4
No arc occurs when 3 is released. Next, the buffer-type cutoff section is opened, followed by the vacuum cutoff section.

However, in this structure, the vacuum cut-off part 5 is arranged on the fixed contact side 6 of the buffer-type cut-off part 4, so when the current is cut off, the high-temperature scum blown out from the buffer-type cut-off part i4 is transferred to the vacuum cut-off part 5. will be sprayed on. Therefore, it is clear that the insulation between the fixed contact side end plate 20 of the vacuum cutoff section 5 and the fixed side energizing contact 420 is threatened, and that the creeping dielectric strength voltage of the insulator container 19 of the vacuum cutoff section 5 is reduced. became.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a composite shutoff device with excellent insulation performance by preventing high-temperature gas blown from a buffer-type shutoff section from blowing against a vacuum shutoff section.

[Summary of the invention]

In order to achieve this object, the present invention provides a composite shutoff device in which a buffer type cutoff part and a vacuum cutoff part are connected in series, in which the vacuum cutoff part and the movable contact side of the buffer type mirror cutout part are directly connected. On the fixed contact side end plate of the vacuum cutoff section,
A fixed-side current-carrying contact that passes through the outside of the vacuum cut-off part and extends to the buffer-type cut-off part is attached, and a movable-side current-carrying contact that contacts the fixed-side current-carrying contact in the closed state is attached to the buffer cylinder of the buffer-type cutoff part. It is characterized by the provision of a contactor.

[Embodiments of the invention]

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

This cutoff device has a buffer type cutoff section 4 and a vacuum cutoff section 5 housed in one container 41, and there are 8 traps in the container 41.
Filled with Fe waste. In the buffer type circuit breaker 4 and the vacuum cutoff section 5, each movable contact 6 and 16 is connected to the movable contact side end plate 20. of the vacuum cutoff section. The piston support fitting 11, the piston 10, and the buffer cylinder 8 are electrically connected in series. A cylindrical fixed-side energizing contact 50 disposed on the outer periphery of the buffer cylinder 8 of the buffer-type cut-off part 4 is supported and fixed on the fixed-contact side end plate 21 of the vacuum cut-off part 5, and is electrically connected. A current-carrying contact support fitting 51 is attached for this purpose.

On the other hand, the buffer cylinder 8 has the above-mentioned one in the closed state.
A movable-side energizing contact 52 that contacts the mlm measuring contact 50 is provided. 52 movable side energizing contacts,
The outer circumference of the buffer cylinder 8 has a structure that has a diameter larger than the outer diameter of the buffer cylinder, and in the open state,
A gap is created between the outer periphery of the buffer cylinder and the fixed side energizing contact 52 to maintain electrical insulation.

With the above configuration, in the closed state, the center conductor 13 of one bushing - the fixed contact side end plate 21 - the energizing contact support metal stem 51 - the fixed side energizing contact 50 - the movable side energizing Contact 52 - buffer cylinder 8't - movable current-carrying contact 53 of buffer-type cut-off section - fixed-side current-carrying contact 54 - buffer-shaped section fixed contact side end plate 55 - of the other bushing. A current will flow through the center conductor 24. Current-carrying contacts 50, 52 and 5
Since the contact area of 3.54 can be made large, it is possible to maintain a stable conduction state without generating heat or welding noise at the contact portion even when the current flowing in the steady state is sufficiently large. Further, the fixed-side energizing contact 54 is connected to the vacuum cut-off portion 5
Since it extends from the fixed contact side end plate 21 to the movable side of the buffer type cut-off part, the contact parts of the contacts 16 and 17 of the vacuum cut-off part 5 are short-circuited in the closed state, thereby preventing current flow in the steady state. #1 Tondoga energizing contact 50
．． 52, there is no concern about heat generation or welding even if the current carrying capacity of the contacts 16 and 17 of the vacuum cutoff part 5 is insufficient, and the force for applying the contact force is small. Furthermore, since the contact area only needs to be small, the vacuum connecting section can be made small and require less operating force.

A shunt current also flows through the contact parts of the contacts 16 and 17 of the vacuum interrupter 5, but since this current is small, heat generation due to contact resistance is not a problem, so materials with low wear and tear are used as the contacts where arcing occurs. This is advantageous in terms of equipment design, as it allows the user to freely select materials that do not require consideration of welding.

The shutoff operation is performed as follows. An operating device (not shown) drives the insulating operating rod 60 downward in the figure.
Then, the buffer cylinder shaft 64 connected by the link 61, the lever 62, and the link 63 operates. Then, first, the energizing contacts 50.52 and 53.54
is released. At this time, the contactor 6 of the buffer type interrupting part 4,
7 and the contacts 16 and 17 of the vacuum cut-off part 5 are fully in contact, so the energizing contacts 50, 52 and 53° 5
4, no arc occurs when they open. Next, the contacts 6.7 of the buffer-shaped S-section 4 are opened. The vacuum cutoff section 5 starts the full cutoff operation when the movable contact 170 rod 65 and the insulated operating rod 60 have passed the determination distance L'kd, and the buffer type gas circuit breaker opens and then opens. It is preferable to -r. By doing this,
After interrupting a large current of di/+lt, a transient recovery voltage is applied to both the buffered interrupter and the vacuum interrupter, but d
Immediately after cutting off a current with a large i/dt, the dielectric strength voltage recovery between the electrodes of the buffer type disconnection section is not sufficient due to its thermal history.
Its impedance is in a low state. On the other hand, in the vacuum cut-off section, the speed of insulation recovery is faster than in the buffer-type cut-off section, so the impedance of the four stages becomes large. Therefore, immediately after the current is disconnected, especially for a period of about 0 to 10 μs, a transient recovery voltage is applied to the vacuum cutoff section due to the impedance relationship. After the performance-determining range due to thermal breakdown has passed, the dielectric strength of the buffer-type cut-off part recovers significantly (-<), so even if the vacuum cut-off part side has dielectric breakdown, the buffer-type cut-off part will not suffer dielectric breakdown. do not have.

In addition, in the above-mentioned interrupting device, during the current interrupting process, between the fixed side energizing contact 50 and the buffer cylinder/- cylinder 8,
The voltage between the electrodes of the vacuum cut-off part is applied, but the fixed-side current-carrying contact 50 and the buffer cylinder 8 are arranged in a substantially coaxial cylindrical shape, and the high-temperature gas blown from the buffer-type cut-off part comes into contact with them when the current is cut off. It is preferable in terms of insulation design because it does not spray between the wires. Further, since the vacuum cutoff part can be arranged on the movable side of the buffer cutoff part, it is possible to eliminate the concern that the high temperature gas blown from the buffer type cutoff part will lower the external creeping dielectric strength voltage of the insulating cylinder of the vacuum cutoff part.

The input operation is performed as follows. When the insulating operating rod 60 is driven upward in the drawing by an operating device (not shown), the contacts 16 and 17 of the vacuum interrupter 5 come into contact first. At this time, the buffer-type cut-off part side still maintains a sufficient withstand voltage, so no direct current flows when the vacuum cut-off part is turned on. Next, the contacts 6.7 of the buffer-type cut section 4 are turned on, and finally the current-carrying contacts 50, 52 and 5 are turned on.
3.54 is closed and the closing operation is completed. therefore,
With this structure, the large current at the time of application only reaches one contact ff of the contacts 16 and 17 of the vacuum interrupter 5, but only during the period from when the buffer type interrupter is applied until the current-carrying contact is applied. After that, most of the superposition flows through the energizing contact section. Therefore, welding does not occur between the contacts of the vacuum interrupter, which is preferable in terms of the input force of the vacuum interrupter and the design of the contact material.

FIG. 3 shows another embodiment of the invention. In this diagram,
The same or equivalent parts as in FIG. 2 are given the same reference numerals.

This embodiment differs from the one in FIG. From the end plate 55 supporting and fixing the child 6,
This is through the insulating support 70. By adopting this structure, the fixed contact side end plate 2 of the vacuum cutoff section 5
The connecting portion 71 with the fixed-side current-carrying contact 50 only needs to have sufficient electrical conduction capacity, and should have mechanical strength like the current-carrying contact support metal fitting 51 shown in FIG. Since it is no longer necessary, there are design advantages in terms of size, structure, and placement.

〔Effect of the invention〕

As explained above, according to the present invention, in a composite type breaker device in which the movable contacts of the buffer type breaker and the vacuum breaker are connected in series, the energizing contact of each breaker is The structure opens and closes by the operation of the buffer-type interrupter, which increases the current carrying capacity and completely improves the reliability of the insulation of the current-carrying contact and the outer periphery of the vacuum interrupter container, making it easier to close the vacuum interrupter. Benefits include freedom in selecting force-reducing contact material.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view showing a conventional composite shutoff device;
FIG. 3 is a longitudinal sectional view of a composite shutoff device shown as an embodiment of the present invention. 4... Buffer type cutoff section, 5... Vacuum cutoff section, 6.
... Fixed contact, 7... Movable contact, 8... Buffer cylinder, 16... Fixed contact, 17... Movable contact, 18... Vacuum container, 20... Fixed contact Child side end plate, 21... Movable contact side end plate, 41... Container, 5
o...Fixed side energizing contact, 52...Movable side energizing contact, 53...Movable side energizing contact, 54...Fixed side energizing contact, 55...Fixed contact Child side end plate, 70
...Insulating support. Agent Patent Attorney Akio Takahashi Continued from page 1 0 Inventor: Yes 1) Hiroshi 3-1-1 Saiwaimachi, Hitachi City Hitachi Research Laboratory, Hitachi, Ltd.

Claims (1)

[Scope of Claims] 1. A buffer-type cut-off part and a vacuum cut-off part are connected in series so that their movable contact sides are directly connected, in which a fixed contact-side end plate of the vacuum cut-off part is A fixed-side current-carrying contact extending to the buffer cut-off portion through the outside of the vacuum cut-off portion is attached 1, and when the fixed-side current-carrying contact and A composite type interrupting device characterized by being provided with a movable side energizing contact that comes into contact. 2. In claim 1, the fixed-side energizing contact is connected to the buffer cylinder of the buffer-type interrupting part.
1. A composite shutoff device characterized by having a cylindrical body that is concentric. 3. In the scope of special WFNN requirements, item 1 or 2, the fixed side energizing contact is supported and fixed from the fixed contact side end plate of the buffer type interrupting part via an insulating material support. A complex type shutoff device characterized by: 4. In any one of claims 1 to 3, a fixed-side energizing contact extending from the fixed contact-side end plate of the buffer-type cut-off part to the pack cylinder is attached, and in the closed state. , A composite type interrupting device characterized in that a movable side energizing contact that comes into contact with the fixed side energizing contact is provided in all buffer cylinders.