KR-102961768-B1 - Depositable grounding apparatus for high voltage cable of underground distribution transformer

Abstract

The present invention relates to a grounding mechanism for a high-voltage cable of an underground distribution transformer, wherein a connection terminal connected to an arc rod of an elbow connector is provided inside a body, a cable is connected to the connection terminal, and a grounding wire connection means or an earth grounding means is provided on the cable. Grounding of underground power distribution lines can be easily performed by inserting and connecting a body to the elbow connector of a high-voltage cable, and reliable grounding can prevent component burnout and electric shock accidents.

Inventors

• 최재용
• 동은주
• 이규찬

Assignees

• 한국전력공사

Dates

Publication Date

20260513

Application Date

20240912

Claims (1)

1. An insulating body that is inserted and coupled to an elbow connector of a high-voltage cable; A connection terminal installed inside the above body, which is electrically connected to the arc rod of the elbow connector when the body is inserted into the elbow connector; Cable connected to the above connection terminal; A connecting member made of a conductive material connected to the other end of the above cable; A grounding rod made of a conductive material that is driven into the ground through a through hole formed in the above-mentioned connecting member to form a ground; A mounting part that is inserted and coupled to a parking stand installed on the inner separation wall of the enclosure of an underground distribution transformer at the rear end of the above body to support the above body; and A disc-shaped head portion formed at the top of the body of the grounding rod and pressed against the connecting member; Includes, A coupling hole is formed axially in the above-mentioned connection terminal, into which the arc rod of the elbow connector is inserted and coupled, and A grounding mechanism for a high-voltage cable of a mountable underground distribution transformer, wherein a fixing part is formed protruding radially inward and inserted into a locking groove formed on the arc rod of an elbow connector in the above coupling hole.

Description

Depositable grounding apparatus for high voltage cable of underground distribution transformer The present invention relates to a grounding mechanism for a high-voltage cable of an underground distribution transformer, and more specifically, to a grounding mechanism for a high-voltage cable of an underground distribution transformer that is connected to the high-voltage side cable of the underground distribution transformer to ground the distribution line. Typically, in Korea, the electricity produced by power plants such as hydroelectric, thermal, and nuclear power plants has a voltage of approximately 10,000 to 50,000 volts. This generated current is stepped up to 154,000 volts or 345,000 volts at a high-voltage substation and then sent to a low-voltage substation. At the low-voltage substation, the voltage is reduced to 22,000 to 66,000 volts and transmitted to a transformer near the consumer. Finally, the current is reduced to 220 volts at the transformer near the consumer and supplied to the consumer. Transmission and distribution lines for supplying electricity from power plants to consumers consist of overhead line sections where wires are connected via steel towers, utility poles, etc., and underground line sections where wires are buried underground. Recently, underground line construction is frequently carried out in urban areas for aesthetic and safety reasons. In the underground line system described above, transformers are not installed on top of utility poles but are typically installed in a box shape on the sidewalk along the road. Such transformers are also commonly referred to as ground transformers. As shown in FIG. 1, the underground distribution transformer (10) is structured such that a ‘transformer body (not shown)’ (hereinafter referred to as ‘transformer’) is installed inside a rectangular box-shaped enclosure (11) having a door (12) on the front. Inside the above enclosure (11), there is a partition wall that separates the space containing the transformer and the space in front thereof, and the partition wall is divided into a high-pressure side wall (13) and a low-pressure side wall (14). A bushing insert (not shown) electrically connected to the high-voltage current input terminal of a transformer is installed on the high-voltage side wall (13), and a high-voltage cable (16) connected to the current supply side underground line is connected to the bushing insert via an elbow connector (15). In addition, a parking stand (17) is installed on the high-pressure side wall (13) so that an elbow connector (15) separated from the bushing insert can be placed thereon. A low-pressure side terminal (18) is installed protruding from the low-pressure side wall (14), and a low-pressure cable (19) connected to the underground line on the consumer side is connected to the low-pressure side terminal (18). Accordingly, the current is input to the transformer through the high-voltage cable (16), and the reduced secondary current flows along the low-voltage cable (19) and the underground line connected to the consumer side to be supplied to each consumer. Meanwhile, for the repair or replacement of a transformer, the underground line where the transformer is installed is first de-energized, and subsequently, the de-energized underground line is grounded to prevent potential electric shock accidents. Grounding of the underground power line can be performed using the high-voltage cable (16), but there is a problem that a dedicated grounding device for the high-voltage cable (16) is not currently provided. Therefore, at the site, a non-standard grounding method is used in which the elbow connector (15) is separated from the bushing insert, the arc rod inside the elbow connector (15) is separated using an L-wrench, another arc rod from which the arc extinguishing part has been removed is reinstalled in the elbow connector (15), and the arc rod and the grounding wire are connected with copper binding or bare copper wire. As described above, since non-standard grounding methods are used, there are many cases where the grounding condition is poor, and consequently, equipment damage such as burnout of transformers or elbow connectors (15) occurs, and there is a problem that the risk of electric shock accidents is ever-present. FIG. 1 is an external perspective view of a typical underground distribution transformer. Figure 2 is a cross-sectional view of an elbow connector connected to a high-voltage cable of an underground distribution transformer. FIG. 3 is a configuration diagram of a grounding mechanism for a high-voltage cable of an underground distribution transformer according to the present invention. FIG. 4 is a drawing illustrating another embodiment of a grounding mechanism for a high-voltage cable of an underground distribution transformer according to the present invention. The present invention is susceptible to various modifications and may have various embodiments, and specific embodiments are