KR20210043857A - Low voltage distribution box of underground location type and method for operating thereof - Google Patents

Abstract

The present invention relates to an underground buried-type dual power low-voltage distribution box and an operation method thereof, comprising: one or more branch circuit breakers (140) connected to a load side main line; and a main circuit breaker (130) connected to two busbars on a power supply side, and provided with a circuit and a switch (131) for connecting or disconnecting the branch circuit breaker (140) to at least one of the two busbars on the power supply side. The present invention has an advantage of being able to strengthen a supply capacity of the low-voltage system by operating in an underground low-voltage line loop method and expanding a supply range.

Description

Underground buried double power low voltage distribution box and its operation method {LOW VOLTAGE DISTRIBUTION BOX OF UNDERGROUND LOCATION TYPE AND METHOD FOR OPERATING THEREOF}

The present invention relates to an underground buried double power low-voltage distribution box, and more particularly, installed in the secondary or intermediate transformer of an underground low-voltage distribution line, and used for branching and separating a fault section of a branch line or a loop lead-in line with another transformer. It relates to an underground buried type dual power low voltage distribution box and its operation method.

Low-voltage distribution boxes for underground distribution lines are not highly utilized due to on-site installation space restrictions (ground installation), and are designed to connect only one power supply, so in the event of a breakdown of a transformer on the ground, a loop line with a nearby transformer can be formed. There is no function.

Moreover, it is a principle to install one low-voltage distribution box for each trunk line, but it is practically difficult to install a low-voltage distribution box that additionally serves as an auxiliary role because it is difficult to install ground equipment in places where there are many restrictions on the installation space of ground equipment such as downtown areas.

In addition, due to the nature of the low-voltage distribution box, there is a risk of a short circuit when submerged, and because it has a lower weight than other ground equipment, it is more susceptible to vehicle collisions, so the field utilization is not high.

Patent Document 1: Registered Patent Publication No. 1824338 (registered on January 25, 2018)

An object of the present invention is an underground buried double power low-voltage distribution box that minimizes power outage complaints by configuring an underground low-voltage line as a loop line, increases power supply reliability, and has a waterproof function and is buried in the basement to increase its utilization, and It is to provide a method of operation.

According to the features of the present invention for achieving the above object, the present invention is connected to at least one branch breaker connected to the load-side trunk line and two power-side busses, and the branch breaker is connected to at least one of the two power-side busses. It includes a main breaker provided with a circuit and a switch to connect or disconnect.

The at least one branch circuit breaker and the main circuit breaker are provided in the distribution box body and the distribution box body, the load-side trunk line is provided on the distribution box body and at least one trunk line connection part for connecting the load-side trunk line to the branch breaker, and the power-side two bus bars are connected to the main It includes first and second bus connections for connecting to the circuit breaker, respectively.

The distribution box body is composed of a lower surface and a side wall, and has a structure in which the upper cover is opened.

And a circuit breaker operation unit disposed on the bottom surface of the upper cover or inside the upper cover to enable operation of the main circuit breaker and the branch circuit breaker.

And a low-voltage cable connected to the trunk line connection portion to connect the load-side trunk line to the branch breaker, and connected to the first and second bus line connection portions to connect the power-side two bus lines to the main breaker.

The low voltage cable is connected to the trunk line connection portion and the first and second bus line connection portions by a lead wire connection method.

The low-voltage cable is inserted into the trunk connection part and the first and second bus connection parts, and is connected to the trunk connection part and the first and second bus connection parts in an internal connection method in which a waterproof cap is applied to close a gap.

The distribution box body is a non-metallic material and is formed of a flame retardant material.

The distribution box body has a size and volume that can be installed in a low-voltage connection box for trunk lines.

The switch is a 3-way switch, and the 3-way switch connects or opens the 1 circuit and 2 circuits, which are two bus lines on the power side, and selectively connects 1 and 2 circuits, which are two bus lines on the power side, with the load side trunk circuit. Works to connect.

The low voltage distribution box is connected to a transformer, and the low voltage distribution box connected to the transformer is connected to a second low voltage distribution box connected to a nearby second transformer to form a loop line,

When the transformer fails, power may be supplied through the low voltage distribution box connected to the second low voltage distribution box of the second transformer to supply power to the load side.

The low voltage distribution box includes a main breaker and a branch breaker, and one circuit of the main breaker of the low voltage distribution box is connected to a transformer, and the second circuit of the main breaker is connected to a second low voltage distribution box of the second transformer. The branch circuit breaker may be connected to the load-side trunk line, and may be selectively connected to at least one of the first circuit and the second circuit of the main circuit breaker.

The low-voltage distribution box may be buried underground and connected to the second low-voltage distribution box.

The low-voltage distribution box of the present invention has an effect of minimizing blackout complaints by configuring an underground low-voltage line as a loop line, increasing power supply reliability, and increasing its utility by embedding it in the basement with a waterproof function.

In addition, the low-voltage distribution box of the present invention has the effect of reinforcing the supply capability of the low-voltage system by eliminating the installation space through the underground burial method, improving the urban environment, and expanding the supply range through the underground low-voltage line loop method.

1 is a conceptual perspective view showing a dual power low voltage distribution box according to an embodiment of the present invention.
2 is a conceptual diagram showing an example in which a dual power low voltage distribution box according to an embodiment of the present invention is installed in a low voltage junction box for trunk lines.
3 and 4 are views showing an example in which a low-voltage cable according to an embodiment of the present invention is connected to a distribution box body by a lead wire connection method.
Figure 5 is a block diagram showing the circuit wiring inside the dual power low voltage distribution box according to an embodiment of the present invention.
6 is a view showing a circuit breaker operation unit according to an embodiment of the present invention.
7 is a block diagram showing a method of operating a dual power low voltage distribution box according to an embodiment of the present invention.
8 is a circuit wiring diagram inside a low voltage distribution box showing an example of a method of operating a dual power low voltage distribution box according to an embodiment of the present invention.
9 is a block diagram showing a circuit wiring inside a dual power low voltage distribution box according to another embodiment of the present invention.
10 is a block diagram showing a state in which one circuit and two circuits are opened in the circuit wiring inside the dual power low voltage distribution box according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The dual power low voltage distribution box (hereinafter referred to as'low voltage distribution box') of the present invention is connected to a transformer and buried underground. The low-voltage distribution box buried underground may form a loop by connecting to a second low-voltage distribution box connected to a nearby second transformer.

As shown in FIG. 1, the low-voltage distribution box 100 has a structure in which the upper cover 120 is coupled to the distribution box body 110 so that there is no risk of flooding even if it is buried underground. The distribution box body 110 has a bottom surface and a side wall integrally formed so that the top is opened, and the top cover 120 is composed of a lid-type top cover capable of maintaining airtightness. The upper cover 120 may be connected to the upper one side of the distribution box body 110 by a hinge 125 to open the inside of the distribution box body 110 in a rotating manner. The upper cover 120 is provided with a fixing device so as not to close by itself after opening.

The distribution box body 110 is provided with a circuit breaker (MCCB) therein. The rated breaking capacity of the circuit breaker is more than 30kA at AC 220/380V, and a adjustable circuit breaker is used to change the rated current, and the adjustable range can be the same as the standard of the existing low voltage distribution box.

1 and 5, a circuit breaker (MCCB) includes a main circuit breaker 130 and one or more branch circuit breakers 140. The distribution box body 110 includes bus connections 111 and 112 for connecting to the main circuit breaker 130 and trunk connection parts 113, 114, 115 and 116 for connecting to the branch circuit breakers 140 on the outer surface. In the embodiment, four branch breakers 140 are provided.

As shown in FIG. 1, the bus connection parts 111 and 112 are composed of a first bus connection part 111 and a second bus connection part 112 in order to connect two power-side lines. The trunk connection parts 113, 114, 115, and 116 are composed of first to fourth trunk connection parts 113, 114, 115, and 116 for connecting to the four trunk lines on the load side.

In the drawing, the first bus connection part 111 and the second bus connection part 112 are arranged one circuit on the left and right side walls of the distribution box body 110, and the first to fourth trunk connection parts 113, 114, 115, 116 are the distribution box body 110. 2 lines are placed on the front and rear side walls.

The first and second bus connection parts 111 and 112 and the first to fourth trunk connection parts 113, 114, 115, and 116 may be arranged in the order of A, B, and C, respectively, and may be given different colors to facilitate identification.

The distribution box body 110 is a non-metallic material and is formed of a flame retardant material. Alternatively, the distribution box body 110 may be formed of a flame retardant material and may be insulated. The distribution box body 110 may have an external ground terminal through which a leakage current can flow.

As shown in FIG. 2, the distribution box body 110 may be installed in the low-voltage junction box 10 for trunk lines so that there is no risk of flooding and connected to a transformer (reference numerals 1 and 1a in FIG. 7). The distribution box body 110 has a size and volume that can be installed in the low-voltage junction box 10 for trunk lines.

For example, the distribution box body 110 has a size and volume that can be installed in the low-voltage junction box 10 for trunk lines of 500×750×650 (width×length×height, mm). It can be installed by constructing a secured pouring type box.

Two power-side buses (1 circuit and 2 circuits shown in FIG. 5) for connecting to the main breaker 130 are connected to the first and second bus connection parts 111 and 112, respectively, and the first to fourth trunk connection parts 113, 114, 115, and 116 ), the load-side trunk line for connecting with each branch breaker 140 is connected.

The low voltage cables 160 are connected to the first and second bus connection parts 111 and 112 and the first to fourth trunk connection parts 113, 114, 115, and 116, respectively. The low voltage cable 160 is connected to the first and second bus connection portions 111 and 112, respectively, and connects the two power buses to the main circuit breaker 130. In addition, the low voltage cable 160 is connected to the first to fourth trunk connection portions 113, 114, 115, and 116, respectively, to connect the load-side trunk line to each branch circuit breaker 140.

The low voltage cable 160 may be connected to the first to fourth trunk connection parts 113, 114, 115, and 116 and the first and second bus connection parts 111 and 112 in a lead wire connection method. In the lead wire connection method, a watertight-treated lead wire is included in the low-voltage distribution box 100, and the low-voltage cable 160 is connected from the outside of the distribution box body 110 with a resin type connecting material or a bolt type connecting material. In this case, it is possible to connect the branch circuit during operation.

For example, as shown in Figs. 3 and 4, the first bus connection 111 has a bushing 111a that is watertight and protrudes to the outside, and a bushing 111a is fitted to the low-voltage cable 160. A connection sleeve 163 having a groove 163a is provided, and the connection sleeve 163 may have a structure connected to the conductor 161 of the low-voltage cable 160 in a press-fitting manner.

When the connection sleeve 163 is coupled with the bushing 111a of the first bus connection part 111, the low-voltage cable 160 of the above structure connects the outer periphery of the first bus connection part 111 to the tip of the low-voltage cable 160. The provided insulating material cover portion 165 may be tightly wrapped to maintain watertightness.

In another embodiment, although not shown, the low-voltage cable 160 is inserted into the first to fourth trunk connection portions 113, 114, 115, and 116 and the first and second bus connection portions 111, 112, respectively, and an internal connection that covers a gap by covering a waterproof cap In this manner, the first to fourth trunk line connecting portions 113, 114, 115, and 116 and the first and second bus connecting portions 111 and 112 may be connected, respectively.

The internal connection method is a method of separating the upper cover 120 and the circuit breaker operation unit to be described later and connecting them in the internal circuit, and the first to fourth trunk connection parts 113, 114, 115, 116 and the first and second busbars from the outside of the distribution box body 110 After inserting the low voltage cable 160 through the connection parts 111 and 112, respectively, the first to fourth trunk connection parts 113, 114, 115, 116 and the first and second bus connection parts 111, 112 are covered with a waterproof cap according to the standard, and the low voltage cable 160 ) And the distribution box body 110 is a method of closing the gap. In the internal connection method, the connection between the low voltage cable 160 and the internal circuit uses a bolt type. In the case of the internal connection method, there is a disadvantage in that the entire circuit must be separated from the power supply even when the branch circuit is connected, but there is an advantage of reducing the volume of the low voltage distribution box because there is no lead wire.

As shown in FIG. 5, the circuit breaker (MCCB) provided in the interior of the distribution box body 110 includes a main circuit breaker 130 and one or more branch circuit breakers 140.

In the embodiment, one main breaker 130 is provided and four branch breakers 140 are provided. The main breaker 130 is connected to the power-side two buses, and a circuit and a switch 131 for connecting or separating the branch breaker 140 to at least one of the two power-side buses are provided. Four branch breakers 140 are connected to the load-side trunk line.

The switch 131 of the main breaker 130 applies a 3-way switch. The 3-way switch can operate to selectively connect or open the 1 circuit and 2 circuits, which are two bus lines on the power side, and selectively connect the 1 and 2 circuits, which are two bus lines on the power side, with the load side main line circuit.

One circuit of the main breaker 130 may be connected to a transformer, and two circuits may be connected to a low voltage distribution box of a nearby transformer.

The 3-way switch includes a connection point (a) that connects one circuit and the load side, a connection point (b, d) that connects one circuit and two circuits, and an OFF point (c) that opens one and two circuits.

A total of 5 switches are installed with one 3-way switch on the power side and 4 breakers on the load side. Each standard must be capable of accommodating a maximum load of 500kVA of ground transformer in the case of the power side, and the load side may use 2 circuits of 630A and 2 circuits of 400A, which may be the same as the standard of the existing low voltage distribution box.

The power-side 3-way switch operates in three modes: circuit 1 (power 1), circuit 2 (power 2), and open, and load switching operation between circuit 1 (power 1) and circuit 2 (power 2) is up to 30 cycles. It takes place within (Cycle).

6, the low-voltage distribution box 100 includes a circuit breaker operation unit 150. The circuit breaker operation unit 150 enables the operation of the main circuit breaker 130 and each branch circuit breaker 140. The circuit breaker operation unit 150 is disposed on the bottom of the upper cover 120 or inside the upper cover 120, and opens the upper cover 120 to enable the operation of the main circuit breaker 130 and each branch circuit breaker 140. do.

The circuit breaker operation unit 150 includes an operation unit for operating the input (ON) and opening (OFF) of 1 circuit (power 1) and 2 circuits (power 2) of the main circuit breaker 130, and the closing (ON) of each branch circuit breaker 140. ) And one or more operating units for operating (OFF).

As shown in (a) of FIG. 7, the existing underground low-voltage line system constitutes a dendritic line from the transformer to the end, and the area requiring high reliability can configure an open ring system with different transformers (T). have. However, it is difficult to construct a loop line with the existing low-voltage distribution box (D).

However, as shown in (b) of FIG. 7, the dual power low-voltage distribution box of the present invention is buried underground and can be operated by configuring a low-voltage loop line.

The operation method of the dual power low-voltage distribution box is to connect the low-voltage distribution box 100 to the transformer 1, and the second low-voltage distribution box 100a connected to the low-voltage distribution box 100 connected to the transformer 1 and the nearby second transformer 1a. It can be connected to the loop (loop) line. In addition, when the transformer 1 fails, power may be supplied to the load side by receiving power through the low voltage distribution box 100 connected to the second low voltage distribution box 100a of the second transformer 1a.

For example, assuming that the transformer 1 is broken, long-term corrections due to replacement and repair cause customer complaints and waste of social costs of the low-voltage system. At this time, the problem can be solved by supplying temporary power to the low voltage distribution box 100 of the broken transformer 1 through the second low voltage distribution box of the adjacent second transformer 1a.

In this case, the power connection between the faulty transformer 1 and the low voltage distribution box 100 is cut off, and the second low voltage distribution box and the load side are connected so that a temporary current is supplied to the trunk line of the load side. In addition, when the temporary system capacity is exceeded, it is possible to select and operate only important loads through operation of the load-side branch circuit of the low-voltage distribution box 100.

Specifically, as shown in Fig. 8, the low-voltage distribution box 100 includes a main breaker 130 and a branch breaker 140, and one circuit of the main breaker 130 of the low-voltage distribution box 100 is a transformer (Fig. 7 is connected to the reference numeral 1), and the two circuits of the main circuit breaker 130 are connected to the second low-voltage distribution box 100a of the second transformer (reference numeral 1a in FIG. 7 ). In addition, the branch breaker 140 of the low voltage distribution box 100 is connected to the load-side trunk line, and is selectively connected to at least one of the first circuit and the second circuit of the main circuit breaker 130.

The transformer and the low-voltage distribution box are connected in one circuit, the low-voltage distribution box and the second low-voltage distribution box are connected in two circuits, and the second low-voltage distribution box and the second transformer are connected in one circuit and operated.

If the transformer is fixed during this process, the connection between the 1st and 2nd circuits of the low voltage distribution box is opened (OFF), and the connection between the 2nd circuit and the load-side trunk line is maintained in an ON state. The connection between the 1st circuit and 2nd circuit of the second low-voltage distribution box and the 1st circuit and the load-side trunk line maintains an ON state.

Accordingly, while supplying power from the second transformer to the load side through the second low-voltage distribution box, the low-voltage distribution box connected to the faulty transformer may receive temporary current from the second low-voltage distribution box and supply power to the load side.

Since the low-voltage distribution box is buried underground and connected to the second low-voltage distribution box, it is possible to expand the low- to medium-voltage line protection facilities by eliminating the installation space, improving the urban environment, and improving the reliability of power supply.

In addition, the low-voltage distribution box installed in the ground may form a loop system of a low-voltage line and temporarily supply it to the load side by temporarily supplying it to the load side when a transformer breaks down, thereby solving civil complaints for a long time outage.

In addition, the above-described dual power low voltage distribution box can enhance the supply capability of the low voltage system by expanding the supply range in the underground low voltage line loop method.

Meanwhile, as another embodiment, as shown in FIG. 9, the low-voltage distribution box 100 ′ may be configured with a switch of the main circuit breaker 130 in the form of a rotary switch 130a.

Specifically, the low-voltage distribution box 100' includes a main breaker 130 and a branch breaker 140, and one circuit of the main breaker 130 of the low-voltage distribution box 100' is connected to the transformer and the branch breaker 140 And, the two circuits of the main breaker 130 are connected to the second low-voltage distribution box (reference numeral 100a in Fig. 7) of the second transformer (reference numeral 1a in Fig. 7), and the first circuit and the second circuit of the main breaker 130 May be connected or opened by manipulation of the rotary switch 130a.

The rotary switch 130a of the main circuit breaker 130 may selectively open one circuit and two circuits by rotation, and may selectively connect or open the branch circuit breaker 140 to one or two circuits.

9 is a state in which the rotary switch 130a connects one circuit and two circuits, and FIG. 10 is a state in which the rotary switch 130a opens one and two circuits. In FIG. 9, the branch breaker 140 is connected to one circuit and two circuits, and in FIG. 10, the branch breaker 140 is connected to one circuit.

The present invention has been disclosed in the drawings and in the specification, the best embodiments. Here, specific terms have been used, but these are only used for the purpose of describing the present invention and are not used to limit the meaning or the scope of the present invention described in the claims. Therefore, the present invention will be understood by those of ordinary skill in the art that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical scope of the present invention should be determined by the technical idea of the appended claims.

100: low pressure distribution box 110: distribution box body
111a: bushing 120: upper cover
125: hinge 111,112: bus connection
113,114,115,116: trunk line connection
130: main breaker 140: branch breaker
150: circuit breaker control unit 160: low voltage cable
161: conductor 163: connection sleeve
163a: groove 165: cover portion
1: transformer 1a: second transformer
10: low voltage junction box for trunk line 100a: second low voltage distribution box

Claims (14)

One or more branch breakers connected to the load-side trunk line; And
A main circuit breaker connected to the power-side two bus lines and having a circuit and a switch for connecting or separating the branch breaker to at least one of the two power-side bus lines;
An underground buried type dual power low voltage distribution box including a. The method according to claim 1,
A distribution box body including the one or more branch circuit breakers and the main circuit breaker;
One or more trunk line connecting portions provided on the distribution box body and configured to connect the load-side trunk line to the branch circuit breaker; And
First and second bus bar connection units provided on the distribution box body and configured to connect two power buses to the main circuit breaker, respectively;
An underground buried type dual power low voltage distribution box including a. The method according to claim 2,
The distribution box body is composed of a lower surface and a side wall, and an upper cover is opened in an underground buried type dual power supply low voltage distribution box. The method of claim 3,
An underground buried type double power low-voltage distribution box including a circuit breaker operation unit disposed at the bottom of the upper cover or inside the upper cover to enable the operation of the main circuit breaker and the branch circuit breaker. The method according to claim 2,
An underground buried double power supply low voltage including a low voltage cable connected to the trunk connection part to connect the load-side trunk line to the branch breaker, and connected to the first and second bus connection parts to connect the two power buses to the main breaker Distribution box. The method of claim 5,
The low voltage cable is an underground buried type double power low voltage distribution box connected to the trunk line connection part and the first and second bus connection parts by a lead wire connection method. The method of claim 5,
The low-voltage cable is inserted into the trunk connection part and the first and second bus connection parts, and is connected to the trunk connection part and the first and second bus connection parts in an internal connection method in which a waterproof cap is covered to close the gap. Distribution box. The method according to claim 2,
The distribution box body is a non-metallic material and is formed of a flame-retardant material. The method according to claim 2,
The distribution box body is an underground buried double power low-voltage distribution box having a size and volume that can be installed in a low-voltage junction box for trunk lines. The method according to claim 1,
The switch is a 3-way switch,
The 3-way switch is
Connect or open the 1 circuit and 2 circuits, which are two bus lines on the power side,
An underground buried type dual power low voltage distribution box that operates to selectively connect one circuit and two circuits, which are two bus lines on the power side, to the main line circuit on the load side. The low voltage distribution box is connected to a transformer, and the low voltage distribution box connected to the transformer is connected to a second low voltage distribution box connected to a nearby second transformer to form a loop line,
A method of operating an underground buried double power low voltage distribution box in which power is supplied to a load side by receiving power through the low voltage distribution box connected to the second low voltage distribution box of the second transformer when the transformer fails. The method of claim 11,
The low voltage distribution box includes a main circuit breaker and a branch circuit breaker,
One circuit of the main breaker of the low voltage distribution box is connected to a transformer, and the second circuit of the main breaker is connected to a second low voltage distribution box of the second transformer,
The branch breaker of the low-voltage distribution box is connected to the load-side trunk line, and is selectively connected to at least one of one and two circuits of the main breaker. The method of claim 11,
The low-voltage distribution box is buried underground and connected to the second low-voltage distribution box. The method of claim 11,
The low voltage distribution box includes a main circuit breaker and a branch circuit breaker,
One circuit of the main breaker of the low voltage distribution box is connected to a transformer and a branch breaker, and the second circuit of the main breaker is connected to a second low voltage distribution box of a second transformer,
The operation method of the underground buried double power low voltage distribution box in which the one and two circuits of the main breaker and the branch breaker are connected or opened by operation of a rotary switch.

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