JPH0537462Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a split type current transformer installed in a high-voltage electrical circuit.

[Conventional technology]

A conventional high-voltage split current transformer has a structure in which the split core is insulated from both the high-voltage side and the low-voltage side when it is attached to a high-voltage circuit.

[The problem that the idea aims to solve]

In the above-mentioned conventional high-voltage split type current transformer, when an electric wire, that is, the primary conductor 3 is inserted through the window hole 2 of the current transformer 1 as shown in FIG. 3, the dielectric breakdown voltage decreases and the split type core 4 Corona discharge 5 occurs between the primary conductor 3, which is not only dangerous, but also causes problems such as failure of the current transformer.

The object of the present invention is to provide a high-voltage split current transformer that can solve the above-mentioned conventional problems.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a split-type current transformer installed in a high-voltage line, with a specific resistivity of 10 ³ to 10 between the inner surface of the window hole of the current transformer and the abutting end of the split-type core. A connection surface made of a high resistance material of about 10 ⁹ Ωcm, such as electrostatic paint, is provided, and this connection surface electrically connects the creeping surface between the primary conductor and the core.

[Effect]

In the above-mentioned high-voltage split current transformer, the primary conductor and the mating ends of the split core are connected using a high-resistance material, so almost the entire high voltage is applied between the core and the core winding. A predetermined breakdown voltage can be provided. Electrostatic paint has a resistance of several tens of MΩ, so it is not dangerous, and even if partial peeling occurs, the resistance around the peeled part is higher than the insulation resistance between the creeping parts of the peeled part, so the entire voltage is applied to the peeled part. Regardless, no corona discharge occurs.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Reference numerals 12 and 13 represent a pair of core cases, which form a window hole 14 through which an electric wire passes, and are divided along the diameter line. It is molded into
Reference numerals 15 and 16 indicate split cores built into the cases 12 and 13, which are made of, for example, a plurality of laminated thin plates, and have butt ends 17, 17 of one core 15 and butt ends 18, 18 of the other core 16. Use ones that are butted together so that they interlock with each other.
Reference numeral 19 indicates an electrostatic paint coating surface which is applied to the core case 12 so as to electrostatically connect the inner surface of the window hole 14 and the abutting ends 17, 17 of the split core 15, and 20 indicates the core case 13. The electrostatic coating surface is coated to electrostatically connect the inner surface of the window hole 14 and the abutting ends 18, 18 of the split core 16, and these electrostatic coatings include, for example, 10 Use paints with a specific resistivity of ³ to ^{10 9} Ωcm. The electrostatic paint coating surface 19 is provided not only on a part of the divided surface of the core case 12 as shown in FIG. 2, but also on the front part of the divided surface. The electrostatic paint application surface 20 may also be provided on a part of the divided surface of the core case 13, or may be provided on the entire divided surface. Note that the electrostatic paint coating surfaces 19 and 20 may be replaced with an electrostatic tape or other material. Coils 21 and 22 are wound around the split cores 15 and 16.

[Effect of idea]

Since the present invention is constructed as described above, when a high-voltage line electric wire is inserted through the window hole of the current transformer, corona discharge is prevented from occurring between the electric wire and the abutting end of the split core. Since most of the high voltage is applied between the core and the coil, it is possible to withstand high voltage as designed. Electrostatic paint has a high electrical resistance value of several tens of MΩ, so even if problems such as paint peeling occur in some areas, the voltage applied there is low and is shared, so no corona discharge occurs.

[Brief explanation of the drawing]

Figures 1 and 2 show an embodiment of the present invention, where Figure 1 is a sectional view, Figure 2 is a diagram showing the dividing surface of the core case, and Figure 3 is a diagram showing a conventional high-pressure divided type modification. It is a figure which shows the state which inserted the electric wire into the window hole of a sink. 14... Window hole, 15, 16... Split type core, 1
9, 20... Electrostatic paint application surface, 21, 22... Coil.

Claims (1)

[Scope of utility model registration request] In split-type current transformers installed in high-voltage electrical circuits, there is a specific resistivity between the inner surface of the window hole through which the primary conductor of the current transformer is inserted and the butt end of the split-type core.
A high-voltage split current transformer characterized by having a high-resistance connection surface of approximately 10 ³ to 10 ⁹ Ωcm on the case.