JP2008067596A - Switchgear for power distribution - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a switchgear for power distribution that can enhance reliability by expanding protection range to enable short-circuit protection of the entire loads side including circuit breakers. <P>SOLUTION: Circuit breakers 11 arranged in series, current transformers 12, and a zero-phase current transformer 10 are configured in unit, which are mounted on a carrier 14 and accommodated in an incoming switchboard 1. A switchgear unit 9 for power distribution is contactably and separably comprised of a conductor at power supply side 20 and conductors on load side 33, 34. The zero-phase current transformer 10 is arranged at power supply side of the circuit breakers 11 side. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a distribution switchgear constituted by arranging a circuit breaker, a current transformer and a zero-phase current transformer in series.

  As is well known, the switchgear for power distribution is configured by arranging a circuit breaker, a current transformer (instrument current transformer) and a zero-phase current transformer in series. A vacuum circuit breaker is used as the circuit breaker, and a surge absorber is usually provided.

  Such a power distribution switchgear is configured as a unit and mounted on a carriage so as to be housed in a power distribution board. By moving the carriage or moving the unit on the rail, the power supply side conductor and the load side conductor can be contacted and separated. Such a power distribution switchgear is described, for example, in Patent Documents 1 and 2 below.

Japanese Utility Model Publication No.7-11813 JP 2003-189422 A

  Prior art distribution switchgear has a zero-phase current transformer on the load side of the circuit breaker. For this reason, there is a problem that the ground fault detection on the circuit breaker side including the circuit breaker on the power source side of the zero-phase current transformer cannot be performed and the reliability is lowered.

  An object of the present invention is to provide a switchgear for power distribution that can protect the grounding of the entire load side including the circuit breaker and can expand the protection range to improve the reliability.

A feature of the present invention is that a circuit breaker, a current transformer, and a zero-phase current transformer are housed in a power distribution board, and the circuit breaker is configured to be connected to and separated from a power supply side conductor and a load side conductor. In the device
The zero-phase current transformer is disposed on the power supply side of the circuit breaker, and the current transformer is disposed on the load side,
The circuit breaker, current transformer and zero-phase current transformer are configured as a unit, and are mounted on a carriage and housed in a distribution board, and a power supply side terminal and a load side terminal arranged in parallel in the vertical direction are the power supply side conductor and The load-side conductor is configured to be freely connected to and separated from the load-side conductor, and is horizontally attached to the circuit breaker. The zero-phase current transformer surrounds the power-side terminal, and the current transformer surrounds the load-side terminal. When the side on which the power supply side terminal and the load side terminal are disposed is the rear side of the carriage and the opposite direction is the front side, the circuit breaker is disposed on the front side of the carriage, and the rear of the carriage. The zero-phase current transformer and the current transformer are arranged in parallel in a vertical direction on the side, and the power supply side terminal and the load side terminal are respectively connected to the power supply side conductor and the load side by moving the carriage. Horizontally away from conductor And two vertical frames fixed in the vertical direction from the carriage are provided on the carriage, and a zero-phase current transformer mounting bracket is provided on one side in the vertical direction of the two vertical frames, and A current transformer mounting bracket is provided on the other side, the zero phase current transformer having the above-described arrangement is mounted on the zero-phase current transformer mounting bracket, and the current transformer having the above-described arrangement is mounted on the current transformer mounting bracket. Is in being installed and removed .

Another feature of the present invention is that the zero-phase current transformer is a racetrack-type racetrack type zero-phase current transformer that surrounds the three-phase power supply side terminals of the circuit breaker with a single iron core. It is to be configured as .

  In the present invention, since the zero-phase current transformer is disposed on the power source side of the circuit breaker, the ground fault protection of the entire load side including the circuit breaker can be performed, so that the protection range can be expanded and the reliability can be improved.

  The switchgear for power distribution comprises a circuit breaker, a current transformer, and a zero-phase current transformer as a unit and is mounted on a carriage and housed in a power distribution board. The unit is configured to be able to contact and separate from the power supply side conductor and the load side conductor by moving the carriage. The zero-phase current transformer is arranged on the power supply side of the circuit breaker, and the current transformer is arranged on the load side of the circuit breaker. As the zero-phase current transformer, a racetrack type zero-phase current transformer is used in which a single iron core surrounds the three-phase power supply side terminal of the circuit breaker. The unit is equipped with a surge absorber.

  FIG. 1 shows an embodiment of the present invention. FIG. 1 is a side view showing the overall configuration, and shows an example in which two power distribution opening / closing units are stacked in the vertical direction.

  In FIG. 1, the distribution board 1 is partitioned by a partition plate 2, the front side on the right side in the figure forms a circuit breaker chamber 3, and the back side on the left side in the figure forms a cable chamber 4. A door 5 having a handle 6 is provided on the front side of the power distribution board 1. Two ground fault (overcurrent) protection relays 7 a and 7 b are attached to the door 5.

  In the circuit breaker chamber 3, two support plates 8a and 8b fixed to the partition plate 2 are arranged. The two power distribution opening / closing units 9a and 9b are placed on the support plates 8a and 8b. The distribution switching unit 9 includes a zero-phase current transformer (ZCT) 10, a vacuum circuit breaker (VCB) 11, a current transformer 12, and a surge absorber (SA) 13 for protection from external lightning surge. The vacuum circuit breaker (VCB) 11 includes a circuit breaker (vacuum valve) 11a and an operation unit 11b. In addition, although the circuit breaker chamber 3 is provided with a terminal block that is electrically connected to the outside of the distribution board 1, the illustration is omitted.

  The two power distribution opening / closing units 9a and 9b are mounted on the carriage 14, respectively. The distribution opening / closing units 9a, 9b are provided with a control device 15 on the front side, and a handle 16 for pulling out the distribution opening / closing unit 9 in the front direction (right direction in the drawing). The power distribution opening / closing units 9a and 9b are fixed by a lock pin (not shown) in the state shown in the drawing, and when pulling in the front direction, the lock pin is removed and the handle 16 is pulled.

  The arrangement relationship of the zero-phase current transformer (ZCT) 10, the vacuum circuit breaker (VCB) 11, the current transformer 12 and the surge absorber 13 constituting the two power distribution switching units 9a and 9b is as shown in FIG. ing. A zero-phase current transformer 10, a vacuum circuit breaker 11, and a current transformer 12 are arranged in series, and the zero-phase current transformer 10 is arranged on the power supply side of the circuit breaker 11. The current transformer 12 is disposed on the load side of the circuit breaker 11, and a surge absorber 13 is connected to the load side of the circuit breaker 11.

As shown in FIG. 2, the power source side of the zero-phase current transformer 10 is connected to the power source conductor 20 via a connection fitting 17 such as a clip, and the load side of the current transformer 12 is connected to the load side via the connection fitting 17. Connected to conductor. Since the zero-phase current transformer 10, the vacuum circuit breaker 11, and the current transformer 12 arranged in series are attached to the unit 9, when the unit 9 is pulled out in the front direction, the power source side conductor 20 and the load side conductor are not connected. The connection is interrupted.
The two distribution opening / closing units 9a and 9b are stacked in the vertical direction, and as is apparent from the figure, the positional relationship between the power source side and the load side of the circuit breaker 11 in the two units 9a and 9b adjacent in the vertical direction is It is configured to have a vertically symmetrical arrangement. In addition, the positional relationship between the current transformer 12 and the zero-phase current transformer 10 in the two units 9a, 9b is configured to be vertically symmetrical.

  The cable chamber 4 is provided with a power supply side conductor unit 20 that is molded and insulated. As shown in FIG. 7, the power supply side conductor unit 20 is configured by connecting the same phases of three-phase vertical conductors 22R, 22S, and 22T to three-phase horizontal conductors (copper strips) 21R, 21S, and 21T. As shown in FIG. 8, the vertical conductor 22 has a recess formed in the center, and is configured so that the upper end 22 a and the lower end 22 b are exposed from the mold material 23 when the mold conductor 23 is mold-insulated.

  The power supply side conductor unit 20 is attached to the attachment member 25. The attachment member 25 is formed in a rectangular shape and attached to the partition plate 2, and the internal space forms a conductor processing chamber 26. The conductor processing chamber 26 is provided with a bushing 27 to which the zero-phase current transformer 10 of the unit 9a is connected and a bushing 28 to which the zero-phase current transformer 10 of the unit 9b is connected. Bushings 27 and 28 are provided for three phases. In addition, what is actually connected to the bushings 27 and 28 is the power supply side terminal of the circuit breaker 11 constituting the units 9a and 9b.

  The conductor 31 connected to the bushing 27 is connected to the upper end exposed portion 22 a of the vertical conductor 22, and the conductor 32 connected to the bushing 28 is connected to the lower end exposed portion 22 b of the vertical conductor 22.

  A bushing 29 to which the current transformer 12 of the unit 9a is connected and a bushing 30 to which the current transformer 12 of the unit 9b is connected are provided on the cable chamber 4 side of the partition plate 2. Bushings 29 and 30 are also provided for three phases. A load side conductor 33 is connected to the bushing 29, and a load side conductor 34 is connected to the bushing 30. The load side conductors 33 and 34 are partially omitted. In addition, what is actually connected to the bushings 29 and 30 is the load side terminal of the circuit breaker 11 constituting the units 9a and 9b.

  An inspection port (square hole) 35 of about 400 mm is formed in the lower part of the partition plate 2. The inspection port 35 is covered with a cover plate 36 formed of polyester resin or the like attached to the partition plate 2 with bolts. Also, a square hole inspection port 37 is formed in the ceiling plate of the cable chamber 4 and is covered with a cover plate 38.

  The power distribution opening / closing unit 9 is configured as shown in FIGS. 3 is a perspective view of the unit 9 viewed from the front side, FIG. 4 is a perspective view of the unit 9 viewed from the back side, FIG. 5 is a perspective view of the unit 9 removed from FIG. 4, and FIG. It is a disassembled perspective view.

  3 to 6, the unit 9 has a bar-shaped handle 16 attached to the front surface of the vacuum circuit breaker 11. The interruption part 11 a and the operation part 11 b of the vacuum circuit breaker 11 are mounted on the front side of the carriage 14. The blocking part 11a is formed by three insulating cylinders. The carriage 14 includes four wheels 39.

  Covers 42 are provided on the vertical frames 40 fixed on both sides of the operation unit 11 b of the circuit breaker 11. The cover 42 is bent horizontally in the opposite direction at the upper and lower ends. The instrument mounting plate 41 is fixed to the vertical frame 40, and the control instrument 15 is mounted on the instrument mounting plate 41.

  Two vertical frames 43 are fixed to the rear side of the carriage 14, and the vertical frame 40 and the vertical frame 43 are connected by a connecting frame 44. The surge absorber mounting bracket 45 is fixed to the connecting frame 44. The three surge absorbers 13 are attached to the mounting bracket 45.

  As shown in FIGS. 4 and 5, three power supply side terminals 47 on the upper side and three load side terminals 48 on the lower side are horizontally attached to the breaker 11 a of the breaker 11. A zero-phase current transformer mounting bracket 46 is provided above the two vertical frames 43. The zero-phase current transformer 10 is a racetrack type zero-phase current transformer that surrounds the three-phase power supply side terminal 47 of the circuit breaker 11 with one iron core, and is attached to the zero-phase current transformer mounting bracket 46 by bolting.

  A current transformer mounting bracket 49 is provided below the two vertical frames 43. The current transformer 12 is arranged at the two-phase load side terminal 48 in the three-phase load side terminal 48 of the circuit breaker 11 and attached to the current transformer mounting bracket 49. When the two vertical frames 43, the connecting frame 44, the mounting brackets 45, 46, 48, etc. are removed, the equipment arrangement is as shown in FIG. 5, and when disassembled, it is as shown in FIG.

  The switchgear for power distribution according to the present invention is configured as described above, but the circuit breaker, current transformer, and zero-phase current transformer are housed in the power distribution board, and the circuit breaker is freely connected to and separated from the power supply side conductor and the load side conductor. Since the zero-phase current transformer is arranged on the power supply side of the circuit breaker, the ground fault protection of the entire load side including the circuit breaker can be performed, so the protection range can be expanded and the reliability can be improved. .

  In the above-described embodiment, the circuit breaker, the current transformer, and the zero-phase current transformer have a unit configuration, so that the size can be reduced.

  In the above embodiment, the zero-phase current transformer is arranged on the power source side of the circuit breaker. However, both the current transformer and the zero-phase current transformer may be arranged on the power source side of the circuit breaker '. Of course. Also, the zero-phase current transformer may be elliptical or circular instead of a racetrack, and three meter current transformers are arranged in each phase of the power supply side terminal of the circuit breaker, and the zero-phase current transformer is generated by the three-phase combined output. Obviously, the current may be detected.

  In the above-described embodiment, the circuit breaker is an example of a vacuum circuit breaker. However, it goes without saying that the same effect can be obtained by using an air circuit breaker, a hydraulic circuit breaker, a gas circuit breaker, or the like.

  Further, although the power supply side conductor unit is formed by mold insulation, it is obvious that the power supply side conductor unit may be a cable, an insulated wire, a powder baking coating insulation, a heat shrinkable tube insulation, or the like.

    FIG. 9 shows another embodiment of the present invention. The embodiment of FIG. 9 shows a schematic connection diagram in which the zero-phase current transformer 10, the vacuum circuit breaker 11, and the current transformer 12 arranged in series are dispersedly arranged on the power distribution board 1 without being unitized.

  In FIG. 9, connecting fittings 17 are arranged on the power supply side and the load side of the vacuum circuit breaker 11, and only the circuit breaker 11 is connected to and separated from the power supply side conductor 20 and the load side conductor. Thus, even if the zero-phase current transformer 10, the circuit breaker 11, and the current transformer 12 are arranged in a distributed manner, the same effect as in the first embodiment can be obtained.

  FIG. 10 shows another embodiment of the present invention. In the embodiment shown in FIG. 10, the circuit breaker chamber 3 of the distribution board 1 is configured to be slidable to the front side so that the inspection space 50 is secured. The slide of the circuit breaker chamber 3 can be constituted by a guide rail, for example. In order to enter the inspection space 50, the inspection port 51 formed in the ceiling plate by pulling out the circuit breaker chamber 3 and the inspection port 35 provided in the lower part of the partition plate 2 are used.

  When a plurality of power distribution boards are arranged in a row, an inspection space (inspection passage) 50 as shown in FIG. 11 is formed. In addition, although the inspection channel | path 50 is formed over the whole panel, it is also possible to form the inspection channel | path 50 by pulling out only the distribution board required for the inspection in a panel.

  In the embodiment of FIG. 10, when the inspection of the distribution board is necessary, the necessary inspection space can be secured in the distribution board, so that the inspection space on the back and side of the distribution board is not required, and the rear and side surfaces of the distribution board are removed. It can be installed on the wall of the building, etc., and the installation area can be reduced. In particular, it is effective when a plurality of power distribution boards are arranged in a row.

1 is an overall configuration side view showing an embodiment of the present invention. It is a schematic connection diagram of the power distribution switching unit according to the present invention. It is the perspective view seen from the front side of the switching unit for power distribution by the present invention. It is the perspective view seen from the back side of the switching unit for power distribution by this invention. It is the perspective view which removed the frame from FIG. It is a disassembled perspective view of the switching unit for power distribution by this invention. It is an example block diagram of the insulated conductor unit by this invention. It is sectional drawing of an example structure of the insulated conductor unit by this invention. It is a schematic connection diagram of the switch unit for power distribution which shows the other Example of this invention. It is a block diagram which shows the other Example of this invention. It is explanatory drawing of the other Example shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Power distribution board, 2 ... Partition board, 3 ... Circuit breaker room, 4 ... Cable room, 5 ... Door, 6 ... Handle, 8 ... Support plate, 9 ... Distribution switch unit, 10 ... Zero phase current transformer, 11 DESCRIPTION OF SYMBOLS ... Vacuum circuit breaker, 12 ... Current transformer, 13 ... Surge absorber, 20 ... Power supply side conductor unit, 14 ... Dolly, 47 ... Circuit breaker power supply side terminal, 48 ... Circuit breaker load side terminal.

Claims (8)

In a power distribution switchgear in which a circuit breaker, a current transformer and a zero-phase current transformer are housed in a power distribution board, and the circuit breaker is configured to be freely connected to and separated from a power supply side conductor and a load side conductor.
The zero-phase current transformer is disposed on the power supply side of the circuit breaker, and the current transformer is disposed on the load side,
The circuit breaker, current transformer and zero-phase current transformer are configured as a unit, and are mounted on a carriage and housed in a distribution board, and a power supply side terminal and a load side terminal arranged in parallel in the vertical direction are the power supply side conductor and The load-side conductor is configured to be freely connected to and separated from the load-side conductor, and is horizontally attached to the circuit breaker. The zero-phase current transformer surrounds the power-side terminal, and the current transformer surrounds the load-side terminal. When the side on which the power supply side terminal and the load side terminal are disposed is the rear side of the carriage and the opposite direction is the front side, the circuit breaker is disposed on the front side of the carriage, and the rear of the carriage. The zero-phase current transformer and the current transformer are arranged in parallel in a vertical direction on the side, and the power supply side terminal and the load side terminal are respectively connected to the power supply side conductor and the load side by moving the carriage. Horizontally away from conductor And two vertical frames fixed in the vertical direction from the carriage are provided on the carriage, and a zero-phase current transformer mounting bracket is provided on one side in the vertical direction of the two vertical frames, and A current transformer mounting bracket is provided on the other side, the zero phase current transformer having the above-described arrangement is mounted on the zero-phase current transformer mounting bracket, and the current transformer having the above-described arrangement is mounted on the current transformer mounting bracket. A switchgear for power distribution, characterized in that is attached and removed . 2. The zero-phase current transformer according to claim 1, wherein the zero-phase current transformer is configured as a racetrack-type racetrack type zero-phase current transformer that surrounds the three-phase power supply side terminals of the circuit breaker with a single iron core. Power distribution switchgear. Oite to claim 1, wherein the current transformer for power distribution switchgear, characterized in that disposed on the load side terminal of the 2-phase in the load-side terminals of the three-phase circuit breaker. Oite to claim 1, the other two vertical frames provided in the circuit breaker, the continuous frame the surge absorber mounting bracket is provided, the two two vertical frames with vertical frame of said other A switch frame for distribution , wherein a surge absorber is attached to the surge absorber mounting bracket, and the surge absorber is connected to the load side of the circuit breaker. . Oite to claim 1, power distribution switchgear, characterized in that said circuit breaker is a vacuum circuit breaker. Oite to claim 1, wherein the power supply side conductor power distribution switchgear, characterized in that it is in the insulated conductor unit configuration is insulated is combined with the horizontal conductor and vertical conductor. Oite to claim 1, power distribution switchgear, characterized in that two of said units are staked in the vertical direction. Oite to claim 1, wherein the zero-phase current transformer is arranged on the power supply side of the circuit breaker, the current transformer instead of being placed on the load side, the zero-phase current transformer and current transformer Both of these are arranged on the power supply side of the circuit breaker .

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