JP6680228B2 - DC circuit breaker - Google Patents

Description

    The present invention relates to a DC circuit breaker used in a circuit to which a relatively high DC voltage is applied, such as a solar power generation system.

In a solar power generation system, a large number of power generation elements are connected in series to form a solar cell string, so there are several DC circuit breakers provided in the site that connects the solar cell string to equipment such as an inverter. A high DC voltage of 100 to over 1000 V is applied. In order to cut off the DC high-voltage current, two poles of different circuit breakers are connected by electric wires, and a plurality of contacts are connected in series (for example, refer to Patent Document 1).
In addition, it is known to connect the terminal portion with a shorting bar such as a copper plate instead of the electric wire in order to save a space for connecting two different poles with an electric wire. However, when connecting with a copper plate or the like, generally, the surface area decreases and Since the amount of heat decreases, the temperature of the terminal portion rises as compared with the case of connecting an electric wire, and the trip characteristics of the DC circuit breaker may not be satisfied. For this reason, it is known to provide a radiation fin on the copper plate to increase the surface area and prevent a decrease in the amount of heat radiation (see, for example, Patent Document 2).

JP, 2005-8110, A EP2645486A1

  In a conventional DC circuit breaker, when wiring is performed using a copper plate, the cross-sectional area is larger than when wiring is performed between the terminals with an electric wire, and the electrical resistance is reduced. There was the problem of becoming difficult.

  The present invention has been made in order to solve the above problems, and obtains a DC circuit breaker in which current limiting performance does not deteriorate even when different terminal portions of two poles are connected by a shorting bar such as a copper plate. Is.

A DC circuit breaker according to the present invention includes a base, at least two fixed contacts provided on the base and having fixed contacts, and a movable contact having movable contacts that come into contact with and separate from the fixed contacts. An arc-extinguishing device that is provided corresponding to both contacts and that consists of an arc-extinguishing plate that is also provided on the tip side of the movable contact, and that is provided between the arc-extinguishing device and the terminal to exhaust the shut-off gas that is generated when shutting off. And a barrier curtain that is provided on the terminal side of the barrier and that normally closes the exhaust hole and does not close the exhaust hole when shut off, and a short circuit that connects two adjacent terminals. A bar, a heat radiation fin provided on the short-circuit bar and having a fin portion and a pedestal portion composed of a plurality of fins, a terminal cover for covering the terminal, the short-circuit bar, and the heat radiation fin, and a terminal cover provided on the terminal cover for discharging the terminal and the terminal. It is obtained by a arc wall for partitioning between the fins.
Is.

  According to the circuit breaker of the present invention, since the arc cover that separates the power-source-side terminal and the heat-radiating fin is provided in the terminal cover that covers the power-source-side terminal, the short-circuit bar, and the heat-radiating fin, different 2-pole power-source-side terminals can be provided. It is possible to obtain a DC circuit breaker in which the current limiting performance does not deteriorate even when connected by a short-circuit bar.

It is a front view which shows the DC circuit breaker in Embodiment 1 of this invention. It is a front view which shows the state which removed the terminal cover in the DC circuit breaker shown in FIG. It is sectional drawing which followed the XX line in FIG. It is a principal part front view which shows the connection conductor unit of the DC circuit breaker in Embodiment 1 of this invention. FIG. 5 is an enlarged front view of an essential part in which an essential part A shown in FIG. 4 is enlarged. It is explanatory drawing which showed the cross section of the principal part typically in order to demonstrate the condition at the time of interruption | blocking about the DC circuit breaker shown in FIG. It is a front view which shows typically the state which attached the direct-current circuit breaker in Embodiment 2 of this invention sideways. It is a top view which shows typically the state which mounted the direct-current circuit breaker in Embodiment 2 of this invention sideways. It is a front view which shows the short circuit bar of the DC circuit breaker of FIG. It is sectional drawing which followed the YY line in FIG. It is a front view which shows the radiation fin of the DC circuit breaker in Embodiment 2 of this invention. It is a bottom view of the radiation fin shown in FIG. It is explanatory drawing for demonstrating attachment of the terminal cover of the DC circuit breaker in Embodiment 2 of this invention. It is explanatory drawing for demonstrating the attachment process of the radiation fin shown in FIG. It is explanatory drawing for demonstrating fixation of the radiation fin shown in FIG. It is explanatory drawing for demonstrating the direction of the radiation fin when the direct-current circuit breaker in Embodiment 2 of this invention is attached sideways. It is explanatory drawing for demonstrating the direction of a radiation fin when the direct-current circuit breaker in Embodiment 2 of this invention is attached to a vertical direction.

Embodiment 1.
1 is a front view showing a DC circuit breaker according to Embodiment 1 of the present invention, FIG. 2 is a front view showing a DC circuit breaker with a terminal cover removed, and FIG. 3 is a line XX in FIG. FIG. 4 is a sectional view taken along the line, FIG. 4 is a front view of an essential part showing the connecting conductor unit of the DC circuit breaker according to the first embodiment of the present invention, and FIG. 5 is an enlarged view of an essential part A of FIG. 6 is a schematic diagram for explaining the interruption of the DC circuit breaker according to the first embodiment of the present invention.

  As shown in FIG. 1 to FIG. 3, the DC circuit breaker 101 is configured using a housing 10 including a base 11 and a cover 12 which are made of an insulating material. On the base 11, the circuit breaking units 20 for the number of poles are arranged at intervals, and on the upper part of the circuit breaking unit 20, an opening / closing mechanism unit 30 having a known toggle link mechanism is arranged. The cover 12 covers the circuit breaker unit 20 of each pole on the base 11 and the opening / closing mechanism section 30, and the operation handle 31 of the opening / closing mechanism section 30 projects from the handle window hole 12 a of the cover 12.

  The circuit breaker units 20 of the respective poles are configured to be the same as each other, and the crossbar 32 is arranged on the base 11 so as to be common to the circuit breaker units 20 of the respective poles and orthogonal to the circuit breaker units 20 of the respective poles. To be done. The crossbar 32 is rotated about its axis by the opening / closing mechanism section 30, and each movable contact 23 in the circuit breaker unit 20 of each pole is attached thereto. When the crossbar 32 rotates about its axis, the movable contacts 23 of the circuit breaker unit 20 of each pole are simultaneously rotated, and the rotation of the movable contact 23 fixes the movable contact 22. The contact 21 is contacted and opened. The opening / closing mechanism unit 30 includes a known toggle link mechanism, and includes a known trip bar 33 driven by a trip device 40.

  The circuit breaker unit 20 of each pole has a power source side terminal 24 provided on the base 11, a fixed contactor 27 extending from the power source side terminal 24 and having a fixed contact 21, and a contact and a separation of the fixed contact 21. And a movable contact 23 which is provided at one end thereof and which is rotatably held by a crossbar 32. The movable contact 23 is connected to the movable contact 23 through a movable contact holder 26. The tripping device 40, the load-side terminal 25 extending from the tripping device 40, and the arc-extinguishing plate 51 that is provided on the tip side of the movable contact 23 and that surrounds both the contacts 21 and 22 and that is generated at the time of interruption. And an arc extinguishing device 50 for extinguishing the arc. Further, between the arc extinguishing device 50 and the power source side terminal 24, a barrier 60 having an exhaust hole 60a (shown in FIG. 6) for exhausting a blocking gas generated at the time of shutting off, and the power source side terminal 24 side of the barrier 60 are provided. There is provided a barrier curtain 61 which is normally provided to block the exhaust hole 60a, and is closed by the blocking gas to block the exhaust hole 60a when shut off.

  The fixed contact 21 and the movable contact 22 constitute an open / close contact for opening / closing the electric path. When the movable contact 22 contacts the fixed contact 21, the electric circuit between the terminals 24 and 25 is turned on, and when the movable contact 22 is separated from the fixed contact 21, the electric circuit between the terminals 24 and 25. Turns off. At this time, the arc generated between the movable contact 22 and the fixed contact 21 is extinguished by the arc extinguishing device 50.

  The cutoff gas generated when the arc generated between the movable contact 22 and the fixed contact 21 is extinguished is opened on the side farther from the power supply side terminal 24 in the barrier curtain 61 by the gas pressure, and the DC circuit breaker 101 of the DC circuit breaker 101 is opened from the exhaust hole 60a. Released to the outside.

  Next, the connection conductor unit 70 will be described. The connecting conductor unit 70 has a short-circuit bar 71 that electrically connects two different poles of the DC circuit breaker 101, a fin portion 72a including a plurality of fins, and a pedestal portion 72b that holds the fin portion 72a. A metal radiating fin 72 fixed on the upper side, a power source side terminal 24, a short-circuit bar 71, and a resin-made terminal cover 73 for covering the radiating fin 72, and a mounting screw 74 for fixing the short-circuit bar 71 and the radiating fin 72. It consists of and.

  The terminal cover 73 includes an arc wall 73a that partitions the terminal 24 on the power source side and the radiation fin 72, a first ventilation hole 73b formed on the power source side for heat radiation, and a top surface 73e side of the terminal cover 73 for heat radiation. It has a second ventilation hole 73c formed in the side and a third ventilation hole 73d formed in the side surface. The arc wall 73a extends from the pedestal portion 72b to the short-circuit bar 71 side.

  As shown in FIGS. 4 and 5, the terminal cover 73 is provided with the first ventilation holes 73 b at positions corresponding to the spaces between the fins of the heat radiation fin 72. Thereby, the short-circuit bar 71 and the heat radiation fin 72 can be enlarged in a state where the space distance between the short-circuit bar 71 and the heat radiation fin 72 and the outer surface of the terminal cover 73 is maintained, and the heat radiation amount in the limited space can be increased. You can increase.

  Next, the breaking operation of the DC circuit breaker 101 will be described. When a current of a predetermined value or more flows through the circuit breaker unit 20, the trip device 40 rotates and pushes the trip bar 33, whereby the opening / closing mechanism unit 30 is driven and the movable contact 23 is rotated. The rotation of the movable contact 23 causes the movable contact 22 to separate from the fixed contact 21. The arc generated when the movable contact 22 is opened tends to be maintained at the shortest distance between the fixed contact 21 and the movable contact 22. The generated arc is divided into short arcs by the plurality of arc extinguishing plates 51 made of magnetic steel plates that form the arc extinguishing device 50, a voltage drop occurs, and the arc voltage for maintaining the arc rises. When the arc voltage becomes higher than the power supply voltage, the arc will be extinguished.

Next, by extending the arc wall 73a from the pedestal portion 72b to the short-circuit bar 71, the arc wall 73a is surrounded by the top surface of the terminal cover 73, the arc wall 73a, the interphase wall of the power source side terminal portion, and the power source side terminal 24. The operation of the stored buffer space 62 (shown in FIG. 6) will be described.
In the conventional DC circuit breaker, if a short-circuit bar having a reduced resistance is used to prevent the temperature from rising above the electric wire, the breaking current at the time of short-circuit also increases. As a result, the conductive blocking gas containing metallic vapor evaporated by the heat of the arc at the time of breaking increases, so that the arc generated at the time of breaking propagates through this conductive breaking gas and extends from the movable contact 22 to extend to the short-circuit bar. It will reach the radiating fins.

  In this embodiment, as shown in FIG. 6, since the buffer space 62 is provided, the arc and conductive blocking gas generated at the time of breaking push the barrier curtain 61 open, and the buffer space 62 is discharged from the exhaust hole 60a. Is discharged to. At this time, the barrier curtain 61 opens on the top surface 73e side, so the arc and the conductive blocking gas are discharged to the first space 62a sandwiched between the barrier curtain 61 and the top surface 73e, and then to the arc wall 73a. The path is blocked, and the space between the arc wall 73a and the barrier curtain 61 is passed to reach the second space 62b on the power supply side terminal 24 side in the buffer space 62.

  As described above, when the arc and the conductive cutoff gas are discharged from the exhaust hole 60a, when passing through the terminal cover 73 and the first space 62a surrounded by the resin member which is the interphase wall of the power source side terminal portion. A cooling gas is generated from these resins to cool itself and the arc is throttled by this cooling gas, so that the arc voltage increases and the breaking current is limited. Therefore, when the arc and the conductive cutoff gas reach the power supply side terminal 24, the cutoff is completed, and the arc does not reach the power supply side terminal 24.

  A second ventilation hole 73c is provided on the top surface 73e of the terminal cover 73. However, since the second ventilation hole 73c has a diameter sufficiently smaller than that of the exhaust hole 60a, the arc and the conductive cutoff gas can be cut off. Is blocked by the cooling gas generated from the terminal cover 73, and the cooling gas blocks the second ventilation hole 73c, so that the cooling gas does not pass through the second ventilation hole 73c.

  According to the present embodiment, since the resin terminal cover 73 has the arc wall 73a that partitions the power source side terminal 24 and the heat radiation fin 72, the arc and the conductivity discharged from the exhaust hole 60a at the time of interruption. The shutoff gas is guided to the top space 73e of the terminal cover 73, the arc wall 73a, and the wall of the cover 12 surrounding the power supply side terminal, which is surrounded by the first space 62a surrounded by the resin member, and forms the first space 62a. Since it is cooled by the cooling gas generated from the resin, the current limiting performance is not deteriorated.

  Further, since the terminal cover 73 has the arc wall 73a that partitions the power source side terminal 24 and the heat radiation fin 72, it is possible to prevent the conductive heat cutoff gas generated when the current is cut off from touching the heat radiation fin 72. it can.

  Further, by extending the arc wall 73a from the pedestal portion 72b to the short-circuit bar 71, the cut-off gas is reliably shielded, and the short-circuit bar whose resistance is lowered so as not to raise the temperature of the electric wire causes a short circuit. It is possible to prevent the ground fault to the top plate by cooling the conductive gas having an increased size (reduced current limiting performance) in this buffer space.

  Further, since the first ventilation hole 73b and the second ventilation hole 73c are provided on the power source side and the top surface side of the terminal cover 73, it is possible to radiate heat without accumulating heat in the terminal cover 73.

Embodiment 2.
FIG. 7 is a front view schematically showing a state in which the DC circuit breaker according to the second embodiment is laterally attached, FIG. 8 is a top view schematically showing the DC circuit breaker shown in FIG. 7, and FIG. 10 is a front view showing a short-circuit bar of the DC circuit breaker of FIG. 10, FIG. 10 is a cross-sectional view taken along the line YY in FIG. 9, and FIG. 11 is a front view showing the radiation fins of the DC circuit breaker according to the second embodiment. 12 is a bottom view of the radiation fin shown in FIG. 11, FIG. 13 is an explanatory view for explaining the mounting of the terminal cover, FIG. 14 is an explanatory view for explaining the mounting of the terminal cover, and FIG. 15 is shown in FIG. FIG. 16 is an explanatory view for explaining the fixing of the heat radiation fins, FIG. 16 is an explanatory view for explaining the direction of the heat radiation fins when the DC circuit breaker is mounted sideways, and FIG. 17 is a vertical direction for mounting the DC circuit breaker. For explaining the direction of the heat radiation fin It is a bright view.
The connecting conductor unit 80 of the DC circuit breaker 102 according to the present embodiment has a shaft portion on the pedestal portion 82b so that the DC circuit breaker 102 can be radiated without stagnation of heat even when the DC circuit breaker 102 is mounted sideways. Is provided so that the fin portion 82a can be rotated by 90 degrees.

  As shown in FIGS. 7 and 8, the DC circuit breaker 102 is attached so that the direction of the power supply side terminal-the load side terminal is horizontal. As compared with the state shown in FIG. 2 of the first embodiment, the heat radiation fin 82 can be rotated by 90 degrees. Further, as shown in FIG. 8, the third ventilation holes 83d formed on the side surface side are provided at positions corresponding to the fin portions 82a.

Next, a method of rotating the radiation fin 82 will be described with reference to FIGS.
The connection conductor unit 80 has a short-circuit bar 81 having a circular shaft groove 81a, and a radiation fin 82 having a square recess 82c and an insertion rib 82d inserted into the shaft groove 81a.
Further, as shown in FIG. 13, the terminal cover 83 has a fixing rib 83e, a fixing spring 84, and a fixing block 85 having a shape that fits into the recess 82c. Other configurations are the same as those in the first embodiment, and thus the description thereof will be omitted.

  As shown in FIG. 13, in the DC circuit breaker 102, first, the insertion rib 82d of the radiation fin 82 is inserted into the circular shaft groove 81a to position the short-circuit bar 81 and the radiation fin 82. At this time, since the insertion rib 82d can freely move in the circular shaft groove 81a, the heat radiation fin 82 can rotate with respect to the short-circuit bar 81. After that, as shown in FIG. 14, when the terminal cover 83 is attached, the fixing block 85 is fitted into the recess 82 c, so that the terminal cover 83 restricts the rotation of the heat radiation fin 82 and the heat radiation fin 82 with respect to the short-circuit bar 81. Is pressed. By further pushing the terminal cover 83 from this state, as shown in FIG. 15, the terminal cover 83 is fixed to the cover 12, and the fixing spring 84 presses the radiating fin 82 to fix the radiating fin 82.

As described above, since the radiation fin 82 can rotate 90 degrees, the DC circuit breaker shown in FIG. 17 is installed even when the power supply side terminal and the load side terminal of the DC circuit breaker 102 shown in FIG. 16 are mounted horizontally. Even when the direction of the power supply side terminal-the load side terminal of 102 is the vertical direction, the longitudinal direction of the fin portion 82a of the heat radiation fin 82 can be set to be the vertical direction, and heat is accumulated in the terminal cover 83. It is possible to radiate without heat.
Further, in the present embodiment, since the concave portion 82c and the fixing block 85 have a square shape, the radiation fin 82 can be fixed every 90 degrees. The shapes of the recess 82c and the fixing block 85 need not be square, but may be the same even if they are rotated by 90 degrees, such as an octagon.

  According to the present embodiment, by making shaft groove 81a circular, radiation fin 82 can be rotated, and the direction of the fin can be easily changed according to the mounting direction of DC circuit breaker 102. .

  Further, even when the DC groove breaker 102 is externally impacted by the shaft groove 81a and the insertion rib 82d and the force of the fixing spring 84 is temporarily weakened, the radiation fin is prevented from falling off or being displaced. be able to.

  Further, by making the fixing block 85 and the concave portion 82c have a square shape, it is possible to rotate and attach the radiation fins by 90 degrees.

  Further, since the terminal cover 83 is provided with the third ventilation holes 83d at positions corresponding to the fins of the fin portion 82a, it is possible to radiate heat without generating heat retention in the terminal cover 83.

  By fixing the terminal cover to the cover 12, the radiating fins 82 can be rotated and fixed according to the mounting direction of the DC circuit breaker 102. Therefore, one radiating fin depends on the mounting direction of the DC circuit breaker 102. Not radiating heat can be enabled.

10 housing, 11 base, 12 cover, 12a handle window hole,
20 circuit breaker unit, 21 fixed contact, 22 movable contact,
23 movable contact, 24 power supply side terminal, 25 load side terminal,
26 movable contact holder, 27 fixed contact,
30 opening / closing mechanism section, 31 operation handle, 32 cross bar, 33 trip bar,
40 trip device, 50 arc extinguishing device, 51 arc extinguishing plate,
60 barrier, 60a exhaust hole, 61 barrier curtain,
62 buffer space, 62a first space, 62b second space,
70 connecting conductor unit, 71 short-circuit bar,
72 radiating fins, 72a fin portion, 72b pedestal portion,
73 terminal cover, 73a arc wall,
73b 1st ventilation hole, 73c 2nd ventilation hole, 73d 3rd ventilation hole,
73e Top surface, 74 mounting screw,
101 DC circuit breaker.

Claims (4)

  A base, at least two fixed contacts provided on the base and having fixed contacts, and a movable contact provided corresponding to the fixed contacts and having movable contacts that come into contact with and separate from the fixed contacts. An arc-extinguishing device provided corresponding to the both contacts, the arc-extinguishing plate being provided on the tip side of the movable contactor, a terminal connected to the fixed contactor, the arc-extinguishing device, and the arc-extinguishing device. A barrier that is provided between the terminals and has an exhaust hole for exhausting a blocking gas generated when shutting off, and a barrier that is provided on the terminal side of the barrier, normally closes the exhaust hole, and shuts off the exhaust hole when shutting off. A barrier curtain that is not closed; a short-circuit bar that connects two adjacent terminals of the terminals; a heat-dissipating fin that is provided on the short-circuit bar and has a fin portion and a pedestal portion that include a plurality of fins; Short circuit Chromatography, and a terminal cover that covers the heat radiation fins, provided in the terminal cover, the DC circuit breaker and a arc wall for partitioning between the terminal and the heat dissipating fins.   The DC circuit breaker according to claim 1, wherein the arc wall extends from the pedestal portion to the short-circuit bar side.   The DC circuit breaker according to claim 1 or 2, wherein the radiation fin rotates 90 degrees about an axis provided in the short-circuit bar.   4. The DC circuit breaker according to claim 1, wherein the terminal cover is provided with ventilation holes at positions corresponding to between the fins of the heat radiation fin.

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