JPH02303310A - High voltage electric apparatus - Google Patents

Abstract

PURPOSE:To absorb surges effectively by attaching a ring-shaped surge absorbing member, which consists of magnetic substance or high dielectric material and surrounds the periphery of a vessel, to the periphery of the vessel. CONSTITUTION:Vessels 1, 2, and 3 are connected with each other through insulating spacers 7, and insulating gas 4 such as SF6 gas, or the like is filled, and then conductors 5 and 6 are inserted, being insulated and supported by the insulating spacers 7. Ring-shaped surge absorbing members 11, 12, 13, and 14 surrounding the peripheries of the vessels are attached to the peripheries of the vessels 1, 2, and 3, respectively. These surge absorbers are the ones that magnetic substance such as amorphous alloy, ferrite, etc., or high dielectric material such as barium titanate, etc., is made in core shapes. The surge voltage, which is induced by the reflection of surges arising at the joints between the vessels, is absorbed by the surge absorbing members 11-14.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a high-voltage electrical device that suppresses switching surges.

(Conventional technology) Gas-insulated switchgear takes advantage of the excellent insulation performance and arc-extinguishing ability of SF6 gas to be used in new circuit switches, circuit breakers, grounding devices, and instrument transformers necessary for switching operations in power transmission and substations, etc. , lightning arresters, etc. are housed in a sealed container, connected by high-voltage conductors, and these devices are supported and fixed by insulating supports called spacers. With the increase in the capacity of power transmission and distribution systems and the increasing quality of electricity, high-voltage electrical equipment used in power transmission and substations and switchyards is required to have higher voltage, higher current capacity, and higher reliability. However, gas insulated switchgear is now widely put into practical use as a device that satisfies these requirements.

In power systems, disconnectors, circuit breakers, grounding devices, etc. are opened and closed for the purpose of switching systems, inspecting equipment, or eliminating accidents. Overvoltage occurs. The magnitude of this overvoltage can reach several times the operating voltage and may occur on the creepage of spacers supporting high voltage conductors, SFs, gas spaces, or power cables connected to gas insulated switchgear, transformers, etc. There was a possibility that this could lead to an insulation breakdown accident. In addition, the occurrence of surges can cause problems such as malfunction of control equipment installed around the equipment and noise intrusion into broadcast waves and communication systems, which is a major problem that needs to be solved.

Conventionally, in order to suppress this overvoltage, for example, IEEE
Trans, on Power and System
ms, Vol, PAS-104, NO, 5, pH9
9 (May, 1985), there is a method of suppressing overvoltage by matching impedance at the middle or end of a gas-insulated bus, and a method of suppressing surge energy by applying a resistor to the surface of a metal container. Attempts are being made to absorb it.

(Problem to be solved by the invention) However, the frequency component of overvoltage is a high frequency ranging from several tens of kHz to several tens of MHz, and
Since the z-shape differs depending on individual circuit conditions, there are problems in that it is difficult to set matching conditions, and it takes time for the surge to propagate to the surge absorber, making it impossible to effectively absorb the surge. Further, under normal operating conditions, there is a problem in that the loss of the dielectric inserted for the purpose of suppressing surges and the heat generated by the resistor lead to increased loss or heating of the equipment. Furthermore, when installing the device, it is necessary to install it inside the container, which increases the size of the device.

The present invention was proposed to solve the above-mentioned drawbacks, and prevents insulation breakdown accidents, prevents malfunctions of peripheral equipment, and prevents malfunctions of peripheral equipment by suppressing overvoltage that occurs when switching on and off without increasing the internal dimensions of the equipment. Another object of the present invention is to provide high-voltage electrical equipment that can eliminate communication interference.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, in the present invention, a ring-shaped surge absorbing member made of a magnetic material or a highly dielectric material and circulating around the outer periphery of the container is attached to the outer periphery of the container. .

(Function) With this configuration, the surge absorption member can effectively absorb surges, and the reliability of the device against surges can be improved without increasing the internal dimensions of the device.

(Example) An example of the present invention will be described below with reference to FIG. The containers 1.2.3 are connected via insulating spacers 7. Further, the containers 1, 2.3 are filled with an insulating gas 4 such as SF8 gas, and high voltage conductors 5, 6 are inserted therethrough while being insulated and supported by insulating spacers 7.

A switch 8 such as a disconnector or a circuit breaker is disposed between the high voltage conductors 5 and 6.

Furthermore, ring-shaped surge absorbing members 11, 12, 13, 14 are attached to the outer peripheries of the containers 1, 2.3, respectively, and extend around the outer peripheries of the containers.

This surge absorbing member 11, 12, 13, 14 is a core made of a magnetic material such as an amorphous alloy, ferrite, or zinc oxide element, or a highly dielectric material such as barium titanate, and has a low loss with respect to the operating frequency. There is no such thing.

When the disconnector or circuit breaker is opened or closed, a switching surge voltage called a re-electromotive voltage is generated between the poles of the switch 8.

The magnitude of this surge voltage is determined by the system voltage, equipment characteristics, and circuit conditions, and can reach several times the operating voltage. In addition, the frequency components included are several tens of kiloliters.
It is characterized by a high frequency ranging from several tens of MHz to zz. The generated surge voltage propagates through the high voltage conductors 5 and 6 as well as the container 1, but if the container is divided into 1 and 2 or 1 and 3 as in this embodiment, the surge voltage Impedance・
Reflection occurs here because they are different. In this case, a larger surge voltage may be induced. However, if the surge absorbing members 11 and 12 are attached to the outer circumferential surface of the container as in this embodiment, high frequency loss occurs here and the surge energy is absorbed. That is, it becomes possible to suppress the occurrence of surges.

As described above, according to this embodiment, the surge absorbing member 11.
By attaching 12.13.14 to the outer periphery of the container, it is possible to suppress the generation of surge without increasing the dimensions of the internal equipment, so it is possible to suppress the generation of surges without increasing the dimensions of the internal equipment, so it is possible to suppress the generation of surges without increasing the dimensions of the internal equipment. It is possible to prevent problems such as insulation breakdown accidents of cables and transformers connected to the equipment, malfunction of control equipment installed around the equipment, and noise intrusion into broadcast waves and communication systems.

FIG. 2 shows another embodiment of the invention. In this embodiment, surge absorbing materials 20, 21, and 22 are wrapped around the outer periphery of the containers 1, 2.3 in the form of sheets. The surge absorbing members 20, 21, and 22 are made of a material such as an amorphous alloy that has no loss at operating frequencies and only generates loss at surges.

FIG. 3 is an example in which the present invention is applied to the bushing 30 attachment portion. In this case, the impedance change of the device is large, and therefore a larger reflected wave is generated, but by attaching the surge absorbing member 11 according to the present invention to such a location, the surge can be absorbed and suppressed. A similar effect can be obtained by applying it to the cable head where the power cable is attached, or to the end of the high voltage conductor. Further, the present invention is also effective when applied to a part or all of a container for a busbar of a gas insulated switchgear as shown in FIGS. 4 to 7. Furthermore, when the present invention is applied to a three-phase all-in-one disconnection bus, the loss with respect to the operating voltage is further reduced and it is more effective.

〔Effect of the invention〕

As explained above, in the present invention, a ring-shaped surge absorbing member made of a magnetic material or a high dielectric material and circulating around the outer circumference of the container is attached to the outer periphery of the container, so that surges can be effectively absorbed and It is possible to provide high voltage electrical equipment with improved reliability against surges without increasing the size.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a high-voltage electrical device showing one embodiment of the present invention, and FIGS. 2 to 7 are cross-sectional views of high-voltage electrical equipment showing other different embodiments of the present invention. 1, 2. 3... Container, 4... Insulating gas,
5.6...High voltage conductor, 7...Insulating spacer,
8... Switch, 11.12.13, 14.20, 21.22... Surge absorbing member, 30... Bushing. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] A high-voltage electrical device in which a high-voltage conductor is inserted into a container with insulated support, and a ring-shaped surge absorbing member made of a magnetic material or a highly dielectric material is attached to the outer periphery of the container. .