JPH01304627A - Gas insulation electric equipment - Google Patents

Abstract

PURPOSE:To effectively and surely restrain surge in a breaker and to obtain a reliable and cheap structure by manufacturing a shield installed around a high voltage conductor from a structure comprising a ferromagnetic material. CONSTITUTION:Structures 7a, 7b surrounding fixed electrodes 2a, 2b as high voltage conductor members and a movable electrode 3 are formed from those of amorphous metal powder having iron or cobalt as the main component hardened with epoxy resin. An one turn voltage generated around the structures 7a, 7b is evenly applied to the surfaces of the structures 7a, 7b which are not brought into contact with the fixed electrodes 2a, 2b, and therefore, a long insulation distance is obtained. The structures 7a, 7b have thus surge restraining effects while maintaining conventional forms and electric field alleviation effects. Since the insulation of one turn voltage generated in the structure comprising a ferromagnetic material is maintained with a long distance, it is possible to surely restrain surge.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to gas insulated equipment, and provides a method for suppressing high frequency surges generated when a gas insulated disconnect switch is operated. related to gas insulated electrical equipment.

(Prior Art) Gas-insulated switchgears have been widely used in recent years as switchgears for high-voltage circuits used in substations.

This gas-insulated switchgear has a busbar, circuit breaker, disconnect switch, and other attached equipment housed in a grounded metal container, which is highly stable, inert, and nonflammable. It is odorless and harmless, and is insulated and maintained with an insulating gas such as SF, gas, which has a dielectric strength 2 to 3 times that of air, and is used as a switching device for a high-voltage circuit.

Such devices generally have a coaxial structure, and surges generated within the device propagate with almost no attenuation. It is a well-known fact that high-frequency surges are generated in gas-insulated switchgear due to the operation of disconnectors and circuit breakers. In particular, when operating a disconnector, a surge voltage occurs whose wave crest rises in 3 to 5 ns, and the maximum peak value of the following high-frequency vibration of several MHz is more than twice the peak value of the continuous operating voltage (2,0 ρU or more). It is possible. There are examples of dielectric breakdown accidents in oil bushings caused by the sharp wave crest of this surge, and ground faults caused by the arc between the poles of a disconnector and a grounded metal container due to the peak value of the surge. There have been reported cases of this happening. Furthermore, these surges are induced into the grounding system of the gas-insulated switchgear, causing various radio wave interference and destruction of low-voltage control circuits. Therefore, it is necessary to suppress the high frequency surge generated within the gas insulated switchgear by some means.

As one method for suppressing high frequency surges generated when operating a disconnector, a method shown in FIG. 3 is proposed in Japanese Patent Laid-Open No. 61-66510. That is, this figure is a cross-sectional view of the vicinity of the contact of a disconnector installed in a gas-insulated electric device, and 1 in the figure is a grounded metal container, 2a.

Reference numeral 2b denotes a fixed electrode that keeps sliding with the movable electrode 3 and is in electrical contact with it. The fixed electrode 2a and the movable electrode 3 have a structure that allows them to come into contact with and separate from each other, so that they can be connected or separated. Inside the grounded metal container 1,
Filled with insulating gas, fixed electrodes 2a, 2b,
The movable electrode 3 is kept insulated. A ferromagnetic ring 5 is installed around the outer periphery of the fixed electrode 2a, a shield 6a is provided on the outside of the ferromagnetic ring 5, and a gap g is formed between the fixed electrode 2a and the fixed electrode 2a.

A shield 6b is also installed outside the fixed electrode 2b. The large inductance component of the ferromagnetic ring 5 absorbs surges and reduces disconnector surges.

(Problems to be Solved by the Invention) In the conventional example shown in FIG. Prevents it from flowing. Therefore, when the fixed electrode 2a and the movable electrode 3 are separated, an arc 8 is formed, and a disconnector surge occurs, a large voltage is applied to the gap g, and the streamer that has expanded before the arc 8 is formed changes direction. , shield 6a
Therefore, there is a risk that dielectric breakdown will occur between the shield 6a and the movable electrode 3. In this state, the ferromagnetic ring 5 does not play any role and no surge suppressing effect can be obtained.

Furthermore, the surge suppression effect is proportional to the amount of magnetic material, but
In this conventional example, a shield 6a is further installed outside the ferromagnetic ring 5, and since a mounting mechanism for both of them is also required, which is not shown in FIG.
It cannot be said that the space in the vicinity of is being used effectively.

The present invention has been made in view of the above circumstances, and aims to provide gas-insulated electrical equipment that can effectively and reliably suppress disconnector surges, has a highly reliable, compact, and inexpensive structure. purpose.

[Structure of the invention]

(Means for Solving the Problems) The present invention has been made to achieve the above objects, and
The present invention is characterized in that a shield installed surrounding a high voltage conductor for the purpose of alleviating the electric field is made of a structure made of a ferromagnetic material.

(Function) The shield is an absolutely necessary component for its original purpose of alleviating the electric field, and making it from magnetic material is
At the same time as electric field mitigation, it also has the effect of suppressing surges, making effective use of the space inside the grounded metal container. In addition, the one-turn voltage generated around the magnetic material can be uniformly distributed over the shield surface, resulting in a long insulation distance, and at the same time, the shield is designed to have the optimal shape from an electric field perspective. Even if a one-turn voltage is generated in this portion, electric field concentration will not occur and reliability will not deteriorate.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a front sectional view showing one embodiment of the present invention,
Components in the figure that are the same as those in FIG. 3 will be described with the same reference numerals.

In the present invention, the shields 6a and 6b of the conventional example shown in FIG.
Instead, structures 7a and 7b made of a ferromagnetic material are installed. The structures 7a and 7b are structures in which amorphous metal powder containing iron or cobalt as a main component is hardened with epoxy resin.

In FIG. 3, the shields 6a and 6b are ferromagnetic rings 5
Even if it is not installed, it should be installed,
By installing the structures 7a and 7b made of ferromagnetic material, no extra space is required within the grounded metal container. Furthermore, the space inside the shields 6a and 6b that are originally installed can be used 100%.

1 generated around the structures 7a and 7b made of ferromagnetic material.
This is because the turn voltage is uniformly applied to the surfaces of the structures 7a and 7b that are not in contact with the fixed electrodes.

A long insulation distance can be obtained. Therefore, the electric field is
The arc 8 is no longer concentrated in the gap g, and the arc 8 does not move to the structure 7a. In addition, structures 7a, 7
b is originally designed to have an optimal shape in terms of electric field, and without requiring a new electric field design for this part, it is possible to provide a surge suppressing effect while maintaining the conventional shape.

Epoxy resin has a large dielectric constant and also contains amorphous metal powder, which is a conductor, so the apparent dielectric constants of the structures 7a and 7b are as follows.

It gets even bigger. Therefore, the structures 7a and 7b can sufficiently play the original role of mitigating the electric field.

According to this embodiment, the space within the grounded metal container can be used effectively, and an effective surge suppressing effect can be provided without changing the size of the gas-insulated electrical equipment from the conventional size. In addition, since insulation for one turn voltage generated in a structure made of a single ferromagnetic material can be maintained over a long distance, surge suppression can be reliably carried out, and at the same time reliability can be improved. Furthermore, since surge suppression devices can be installed without changing the design of conventional gas-insulated electrical equipment, there is no need for extra design and it can be manufactured at low cost. Equipment can also be equipped with surge suppression functionality by simply replacing parts.

Another possible method is to solidify the structures 7a and 7b with amorphous alloy powder using conductive epoxy.

In this structure, the electric field relaxation effect is caused by the structure 7a,
This is not due to the large dielectric constant of 7b.

This is due to the resistance that the structures 7a and 7b have.

In one embodiment of the present invention, a shield installed near the contact of the disconnector is considered, but the present invention is not limited to this shield. For example, as shown in FIG. 2, a shield 7 installed at a portion connecting a high voltage conductor 9 connecting a disconnector (not shown) and the main bus to a high voltage conductor 11a of the main bus is made of a ferromagnetic material. A similar effect can be obtained even if the structure is manufactured.

〔Effect of the invention〕

According to the present invention, it is possible to provide a disconnector surge suppressing function without changing the design of the gas-insulated electrical equipment, and without significantly changing the size of the gas-insulated electrical equipment from conventional equipment.

In addition, by simply replacing parts, existing gas edge electric equipment can be made to have a disconnector surge suppressing effect.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a gas insulated electric device near a contact point showing one embodiment of the present invention, FIG. 2 is a partial cross-sectional view of a gas insulated electric device showing another embodiment of the present invention, and FIG. 3 is a conventional FIG. 1... Grounded metal container 2a, 2b... Fixed electrode, 3... Movable electrode, 4... Insulating gas,
5... Ferromagnetic ring, 6a, 6b... Shield, 7, 7a, 7b... Structure made of ferromagnetic material, 8
...Arc, 9, lla, llb, 1lc - high voltage conductor. 10...Insulating spacer. Agent Patent Attorney Noriyuki Ken Yudo Daishimaru Ken Figure 1 Figure 2

Claims (3)

[Claims] (1) In gas-insulated electrical equipment in which a high-voltage current-carrying member is placed in a grounded metal container filled with insulating gas, the shield installed surrounding the high-voltage current-carrying member is a structure made of a ferromagnetic material. Gas insulated electrical equipment characterized by being manufactured by. (2) The gas-insulated electric device according to claim 1, wherein the structure made of a ferromagnetic material is made by hardening powder of a magnetic material such as an amorphous metal with an insulating resin such as an epoxy resin. (3) The gas-insulated electric device according to claim 1, wherein the structure made of a ferromagnetic material is made by solidifying powder of a magnetic material such as an amorphous metal with a resistive resin such as a conductive epoxy resin.