JPS6134808Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a capacitor-type voltage transformer using an insulating gas as the main dielectric for use in gas-insulated switchgear.

In recent years, gas insulated switchgear has been increasingly used from the viewpoint of downsizing substations and improving aesthetics. In order to measure the voltage of the live parts of this gas-insulated switchgear, a capacitor-type voltage transformer using an insulating gas as the main dielectric is used.

FIG. 1 shows an example of a conventional configuration. 1 is a grounded metal container, and 2 is a bus bar which is a live part. 3 is an electrode placed between the container 1 and the bus bar 2 forming the main capacitor _C1 . 4 is a disconnector, and this fixed side contact 4b is connected to the bus bar 2. 4a
indicates a disconnector movable contact, which is driven by the operating device 4c. Reference numeral 6 denotes an earthing switch, and its operating device 6b is arranged to face a fixed electrode 6a of the earthing switch. 7 is a lead wire bushing whose one end is connected to the electrode 3, 9 is a voltage dividing capacitor having a capacitance _C2 , and 8 is a voltage divided by the main capacitor _C1 and the voltage dividing capacitor 9 having a capacitance _C2 . This is an amplifier that takes power as input. Depending on the performance of the amplifier 8, the divided voltage of the electrode 3 is determined in each case, and the capacitance of the main capacitor _C1 is determined by the divided voltage. The dielectric material of the main capacitor C ₁ is a gas with a relative dielectric constant of ~1, but using other dielectric materials such as oil in the gas-insulated switchgear is expensive due to the construction.
Also, it is undesirable because it hinders downsizing.
In order to obtain the necessary capacitance C ₁ , the longitudinal direction of the electrode 3 axis can be adjusted appropriately, but if the capacitance C ₁ of the main capacitor is large, the electrode 3 will be longer than necessary, resulting in a reduction in the size of the switchgear. This will hinder the development of For this reason, the distance between the electrode 3 and the bus bar 2 is shortened to the limit that is permissible in terms of insulation, so that a large main capacitor C ₁ can be obtained without increasing the dimension of the electrode 3 in the axial longitudinal direction.

Therefore, in general, the electric field at the electrode 3 and bus bar 2 portions constituting the main capacitor _C1 is higher than other portions. Furthermore, when the charging current switching of the disconnector 4 and the induced current switching of the grounding switch 6 shown in FIG. Generally, the first method is
As shown in the figure, the gas is divided by insulating spacers 5, and care is taken to provide a clean atmosphere of gas in the portion that constitutes the main capacitor _C1 . For this reason, the insulating spacer 5 is required, which hinders the miniaturization of the device and also has the disadvantage of increasing the cost.

Therefore, this proposal was developed in view of the above points, and the purpose is to obtain a capacitor-type voltage transformer for gas-insulated switchgear that eliminates the need for insulating spacers, reduces the size of the device, and allows for inexpensive manufacture. shall be.

Hereinafter, an explanation will be given with reference to an embodiment of the present invention shown in FIGS. 2 and 3. In FIGS. 2 and ₃ , the same parts as in FIG. The electrode 3 is provided with a slit 10.

By configuring in this way, the disconnector 4,
Arc products and the like generated by the current switching of the earthing switch 6 float in the gas, enter the high electric field portion of the electrode 3 and the main capacitor C ₁ of the bus bar 2, and tend to accumulate on the surface of the electrode 3. However, since the electrode 3 is provided with a slit 10, dust such as arc products between the electrode 3 and the bus bar 2 floats in the high electric field area and enters the weak electric field area of the slit 10, which leads to the space between the electrode 3 and the case 1. Since the divided voltage of the capacitor transformer is generally low, the electric field strength between the electric field 3 and the case 1 is very weak, and the arc products that have entered this part are held in this state.

This state is shown in FIG. The arc product is 1
1.

By configuring as above, the main capacitor
In the high electric field portion constituting _C1 , dust such as arc products is captured by the slit 10 provided in the electrode 3 and kept clean, so there is no risk of dielectric breakdown caused by dust such as arc products.

Therefore, since the electrodes constituting the main capacitor of the capacitor-type voltage transformer can be provided in the same gas compartment as the disconnector, grounding device, etc., the insulating spacer 5 for the gas compartment is not required, and the gas insulated switchgear is used. It can be downsized, the structure can be avoided from becoming complicated, and it can be manufactured at low cost.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a conventional device, and FIGS. 2 and 3 are configuration diagrams and explanatory diagrams of essential parts of an embodiment of the present invention. 1... Metal container, 2... Bus bar, 3... Electrode, 4
... Disconnector, 5 ... Insulating spacer, 6 ... Earthing switch, 7 ... Drawer bushing, 8 ... Amplifier, 9
...Voltage dividing capacitor C ₂ , 10 ... Slit, 1
1...Arc product.

Claims (1)

[Scope of utility model registration request] A switch that is filled with an insulating gas and generates an arc product, and a bus conductor connected to the switch is housed in a grounded metal container of a gas-insulated switchgear, which is housed in the same gas compartment as the switch. In a capacitor-type potential transformer, an electrode forming a main capacitor between the bus bar and the bus bar is arranged in the metal container concentrically with the bus bar and at the shortest allowable distance from the bus bar in terms of insulation. A capacitor-type voltage transformer for a gas insulated switchgear, characterized in that the electrode is provided through a slit for collecting dust from arc products generated in a gas compartment housing the switch.