KR20180087100A - Circuit breaker for direct current - Google Patents

Abstract

The present invention provides a direct current circuit breaker, preventing current limiting performance even though a terminal unit with different two poles is connected to a short circuit bar like a copper plate. The present invention comprises: a base (11); at least two fixated contactors (27) arranged on the base (11) and having fixated contact points (21); an actuating contactor (23) having an actuating contact point (22) coming into contact with and being separated from the fixated contact points (21); an arc extinguishing device (50) composed of a plurality of arc extinguishing plates (51) surrounding both contact points (21, 22) and the fixated contactor (23); power side terminals (24) connected to the fixated contactors (27); an opening wall dividing a gap between the power side terminals (24); a short circuit bar (71) connected to two adjacent terminals among the power side terminals (24); a heat dissipating fin (72) arranged in the short circuit bar (71) and having a fin part (72a) composed of a plurality of fins and a base part (72b); a terminal cover (73) covering the power side terminals (24), the short circuit bar (71) and the heat dissipation fin (72); and an arc wall (73a) arranged on the terminal cover (73) to divide the power side terminals (24) from the fin.

Description

{CIRCUIT BREAKER FOR DIRECT CURRENT}

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

In the photovoltaic power generation system, a plurality of power generation elements are connected in series to constitute a solar cell string. Therefore, in the DC circuit breaker provided at a site where a solar cell string is connected to a device such as an inverter, A direct current high voltage of 1000V seconds or more is applied. In order to cut off the DC high voltage current, the two different poles of the breaker are connected by a wire, and a plurality of contacts are connected in series (see, for example, Patent Document 1).

It is also known to connect the terminal portions with short bars such as copper plates instead of wires in order to omit space for connecting the two poles with different wires. Generally, when connected with a copper plate or the like, And the temperature of the terminal portion rises as compared with the case of wire connection, and the trip characteristic of the DC circuit breaker may not be satisfied. For this reason, it is known to provide a heat dissipating fin on the copper plate to increase the surface area, thereby preventing a decrease in the amount of heat dissipation (see, for example, Patent Document 2).

Patent Document 1: JP-A-2015-8110 Patent Document 2: European Patent Publication No. EP 2645486 A1

In the conventional DC circuit breaker, when the wiring is made of a copper plate, the cross-sectional area is wider than that between the terminals by the electric wire, so that the electric resistance is reduced and the interruption current at the time of short circuit becomes large, .

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems as described above, and it is an object of the present invention to provide a DC circuit breaker which does not deteriorate the current limiting performance even when two terminal portions of different polarities are short-

A DC circuit breaker according to the present invention comprises a base, a movable contact provided on the base, having at least two stationary contacts having fixed contacts, movable contacts having contact and openings with the stationary contacts, An arc extinguishing device which is provided in correspondence with the both contacts and which is formed of a arc extinguishing plate provided on a side of the front end of the movable contactor and an arc extinguishing device which is provided between the arc extinguishing device and the terminal, A barrier curtain which is provided on the terminal side of the barrier and which closes the exhaust hole in the normal case and does not block the exhaust hole in the case of shutting off; A terminal cover covering the terminal, the short-circuiting bar, and the heat-radiating fin, and a terminal cover provided on the terminal cover, Is provided, it is provided with a terminal and a heat-arc (arc) wall (壁) dividing between the.

According to the wiring breaker of the present invention, since the arc wall dividing the power-side terminal and the heat-radiating fin is provided in the terminal cover covering the power-side terminal, the short-bar and the heat-radiating fin, even if the two terminals of the power- It is possible to obtain a DC circuit breaker whose performance is not deteriorated.

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 state in which the terminal cover is removed from the DC circuit breaker shown in Fig. 1. Fig.
3 is a cross-sectional view taken along the line X-X in Fig.
4 is a front view of a main part showing a connecting conductor unit of a DC circuit breaker according to Embodiment 1 of the present invention.
5 is an enlarged front view of a main portion enlarged in a main portion A shown in Fig.
Fig. 6 is an explanatory diagram schematically showing a cross section of a main portion for explaining a situation when the DC circuit breaker shown in Fig. 3 is cut off. Fig.
7 is a front view schematically showing a state in which the DC circuit breaker is mounted in the lateral direction in the second embodiment of the present invention.
8 is a top view schematically showing a state in which the DC circuit breaker according to the second embodiment of the present invention is mounted in the lateral direction.
Fig. 9 is a front view showing a short-bar of the DC circuit breaker of Fig. 7; Fig.
10 is a cross-sectional view taken along the line Y-Y in Fig.
11 is a front view showing a heat dissipation fin of the DC circuit breaker according to the second embodiment of the present invention.
12 is a bottom view of the heat dissipation fin shown in Fig.
13 is an explanatory view for explaining the mounting of the terminal cover of the DC circuit breaker in the second embodiment of the present invention.
Fig. 14 is an explanatory diagram for explaining the mounting of the heat dissipation fin shown in Fig. 13;
Fig. 15 is an explanatory diagram for explaining fixing of the heat dissipation fin shown in Fig. 13;
16 is an explanatory view for explaining the direction of the heat radiation fin when the DC circuit breaker according to the second embodiment of the present invention is mounted in the lateral direction;
17 is an explanatory view for explaining the direction of the heat radiation fin when the DC circuit breaker according to the second embodiment of the present invention is mounted in the longitudinal direction.

Embodiment 1

Fig. 1 is a front view showing a DC circuit breaker according to a first embodiment of the present invention, Fig. 2 is a front view showing a DC circuit breaker with a terminal cover removed, Fig. 3 is a cross- Fig. 5 is an enlarged view of a main portion of the main portion A shown in Fig. 4, Fig. 6 is an enlarged view of a main portion of the main portion of the DC circuit breaker according to the first embodiment of the present invention, Fig. Fig. 7 is a schematic view for explaining a case where the DC circuit breaker of the first embodiment is cut off.

As shown in Figs. 1 to 3, the DC circuit breaker 101 is configured by using a case 10 made up of a base 11 and a cover 12 formed of an insulating material. On the base 11, circuit disconnecting units 20 as many as the number of poles are arranged with an interval therebetween, and on the upper part of the circuit interrupting unit 20, an opening / closing mechanical unit (not shown) having a known toggle link mechanism 30 are disposed. The cover 12 covers the circuit breaker unit 20 and the opening and closing mechanism 30 of each pole on the base 11 and the operation handle 31 of the opening and closing mechanism 30 is engaged with the handle window hole 12a.

The crossbar 32 is common to the circuit breaker unit 20 of each pole and is connected to the circuit breaker unit 20 of each pole so as to be orthogonal to the circuit breaker unit 20 of each pole. . This crossbar 32 is pivoted by the opening and closing mechanism 30 about its axis so that the movable contacts 23 of the circuit breaker unit 20 of each pole Respectively. The movable contacts 23 of the circuit breaker units 20 of the respective poles are rotated at the same time when the crossbar 32 rotates about its axial center and the movable contacts 22 Contact with the fixed contact 21 and open. The opening / closing mechanism 30 is formed by a known toggle link mechanism and includes a known trip-bar 33 which is driven by the trip device 40.

The circuit breaker unit 20 of each pole includes a power source side terminal 24 provided in the base 11, a fixed contact 27 extending from the power source side terminal 24 and having a fixed contact 21, A movable contact 22 which contacts and opens with the fixed contact 21, a movable contact 23 which is provided at one end of the movable contact 22 and is rotatably held by the crossbar 32, A trip device 40 connected to the contact 23 through the movable contact holder 26 and a load side terminal 25 extending from the trip device 40 and a load side terminal 25 provided on the tip side of the movable contact 23, And an SOH apparatus 50 for extinguishing an arc generated at the time of interruption by the SOHO plate 51 surrounding the two contacts 21 and 22. A barrier 60 having an exhaust hole 60a (shown in FIG. 6) for exhausting a shielding gas generated at the time of interruption and a barrier 60a for exhausting the barrier gas generated at the time of interruption are formed between the SOH apparatus 50 and the power source- The barrier curtain 61 is provided on the side of the power source side terminal 24 of the power source side terminal 24 of the power source side terminal 60 of the power source side terminal 60 have.

The stationary contact 21 and the movable contact 22 constitute an open / close contact for opening and closing a circuit. When the movable contact 22 is brought into contact with the fixed contact 21, the electric circuit between the both terminals 24 and 25 is turned on. When the movable contact 22 is released from the fixed contact 21, The electric circuit between the terminals 24 and 25 is turned off. At this time, the arc generated between the movable contact 22 and the stationary contact 21 is extinguished by the SOH apparatus 50.

The shield gas generated when the arc generated between the movable contact 22 and the fixed contact 21 is extinguished is opened at the side far from the power source side terminal 24 of the barrier curtain 61 by the gas pressure, And is discharged out of the DC circuit breaker 101 from the exhaust hole 60a.

Next, the connection conductor unit 70 will be described. The connecting conductor unit 70 includes a shorting bar 71 for electrically connecting two different poles of the DC circuit breaker 101 and a base portion 72a for holding the fin portion 72a and the fin portion 72a A metal heat sink 72 that is fixed on the shorting bar 71 with the heat sink 72a and the heat sink 72b covering the power source side terminal 24 and the shorting bar 71, A terminal cover 73 and a mounting screw 74 for fixing the shorting bar 71 and the heat radiating fin 72. [

The terminal cover 73 has an arc wall 73a dividing the power source side terminal 24 and the heat radiating fin 72 and a first vent hole 73b opened to the power source side for heat dissipation and a terminal cover 73 A second ventilation hole 73c opened to the side of the top surface 73e, and a third ventilation hole 73d opened to the side. The arc wall 73a extends from the base portion 72b to the shorting bar 71 side.

As shown in Figs. 4 and 5, the terminal cover 73 is provided with the first ventilation hole 73b at a position corresponding to the space between the fins of the heat-radiating fin 72. [ Thus, the short-circuit-bar 71 and the heat-radiating fin 72 are made larger in a state in which the space distance between the short-circuit-bar 71 and the heat-radiating fin 72 is kept at a space distance from the outer surface of the terminal cover 73 So that the amount of heat radiation in a limited space can be increased.

Next, the breaking operation of the DC circuit breaker 101 will be described. When a current equal to or greater than a predetermined value flows through the circuit breaker unit 20, the trip device 40 rotates and releases the trip-bar 33, so that the opening / closing mechanism 30 is driven to rotate the movable contactor 23. The movable contact 22 is opened from the fixed contact 21 by the rotation of the movable contact 23. An arc generated when the movable contact 22 is opened tries to keep the shortest distance between the fixed contact 21 and the movable contact 22. The generated arc is divided into short arcs by a plurality of small arc plates 51 made of magnetic steel plates constituting the arc furnace 50, so that 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 is extinguished.

Next, the arc wall 73a is extended from the base portion 72b to the shorting-bar portion 71, whereby the surface of the terminal cover 73, the arc wall 73a, the interphase wall of the power- And the buffer space 62 (shown in Fig. 6) surrounded by the power supply side terminal 24 will be described.

In the conventional DC circuit breaker, when a short-bar which has lowered the resistance to lower the temperature than the electric wire is used, the cut-off current at the time of short circuit becomes large. As a result, since the conductive shield gas containing the metallic vapor evaporated by the heat of the arc at the time of interruption also increases, the arc generated at the time of interruption is extended from the movable contact 22 through this conductive shield gas And reaches the heat-dissipating pin of the short-circuiting bar.

6, since the buffer space 62 is provided, the arc curtain and the conductive shielding gas generated at the time of interruption push the barrier curtain 61 to open from the exhaust hole 60a to the buffer And is discharged into the space 62. At this time, since the side of the top surface 73e of the barrier curtain 61 is opened, the arc and conductive blocking gas is discharged into the first space 62a between the barrier curtain 61 and the top surface 73e, A path is blocked in the arc wall 73a and the space between the arc wall 73a and the barrier curtain 61 is connected to the second space 62b on the side of the power source side terminal 24 in the buffer space 62 .

When the arc and conductive shielding gas is discharged from the exhaust hole 60a and then passes through the first space 62a enclosed by the resin member such as the terminal cover 73 and the phase wall of the power source side terminal portion, And the arc is narrowed by the cooling gas. Therefore, the arc voltage rises and the interruption current becomes cold. Therefore, when the arc and the conductive shielding gas reach the power source side terminal 24, the cutoff is completed and the arc does not reach the power source side terminal 24. [

The second ventilation hole 73c is provided on the ceiling surface 73e of the terminal cover 73. The second ventilation hole 73c has a hole diameter sufficiently small as compared with the ventilation hole 60a, The blocking gas is blocked by the cooling gas generated from the terminal cover 73 and the cooling gas does not pass through the second ventilation hole 73c because it blocks the second ventilation hole 73c.

The terminal cover 73 made of resin has the arc wall 73a that divides the power source side terminal 24 and the heat radiation fins 72 so that the arc discharged from the exhaust hole 60a And the conductive shielding gas are guided to the first space 62a surrounded by the resin member such as the ceiling surface 73e of the terminal cover 73, the arc wall 73a and the wall of the cover 12 surrounding the power source side terminal And is cooled by the cooling gas generated from the resin forming the first space 62a, so that the current flow performance is not deteriorated.

Since the terminal cover 73 has the arc wall 73a that divides the power supply side terminal 24 and the heat dissipation fin 72 between the power supply side terminal 24 and the heat dissipation fin 72, Can be prevented.

By providing the arc wall 73a extending from the base portion 72b to the shorting-bar 71, it is possible to reliably shield the shielding gas and to reduce the resistance of the shielding- It is possible to cool the conductive gas (deterioration of the current-flow performance) in this buffer space at the time of short-circuit by the bar to prevent grounding to the top plate.

Since the first ventilation hole 73b and the second ventilation hole 73c are provided on the power source side and the ceiling side of the terminal cover 73, heat can be radiated without generating heat retention within the terminal cover 73. [

Embodiment 2 Fig.

Fig. 7 is a front view schematically showing a state in which the DC circuit breaker in the second embodiment is mounted in the lateral direction, Fig. 8 is a top view schematically showing the DC circuit breaker shown in Fig. 7, Fig. 10 is a cross-sectional view taken along the line Y-Y in Fig. 9, Fig. 11 is a front view showing a heat dissipation fin of the DC circuit breaker in the second embodiment, Fig. 12 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, Fig. 15 is a cross- Fig. 16 is an explanatory view for explaining the direction of the heat dissipation fin when the DC circuit breaker is mounted in the lateral direction, Fig. 17 is an explanatory view for explaining the fixing of the heat dissipation finIt is an explanatory view for explaining the directions.

The connecting conductor unit 80 of the DC circuit breaker 102 in the present embodiment is provided on the base portion 82b so as to be able to dissipate heat without causing any heat stagnation even when the DC circuit breaker 102 is laterally mounted And a shaft portion is provided so that the pin portion 82a can be rotated 90 degrees.

As shown in Figs. 7 and 8, the DC circuit breaker 102 is mounted such that the direction of the power supply side terminal-the load side terminal is horizontal. In the state shown in Fig. 2 of Embodiment 1, the heat radiating fin 82 is rotatable in a state rotated by 90 degrees. In addition, as shown in Fig. 8, the third ventilation hole 83d opened to the side is provided at a position corresponding to the space between the fin portions 82a.

Next, a method of rotating the heat dissipation fin 82 will be described with reference to Figs. 9 to 12. Fig.

The connecting conductor unit 80 includes a shorting bar 81 having a circular shaft groove 81a and an insertion rib 82d inserted into the square recess 82c and the shaft groove 81a And a heat dissipation fin (82).

13, the terminal cover 83 has a fixing block 85 having a shape for fitting the fixing rib 83e, the fixing spring 84, and the concave portion 82c . Other configurations are the same as those of the first embodiment, and a description thereof will be omitted.

13, in the DC circuit breaker 102, first, the insertion rib 82d of the heat dissipation fin 82 is inserted into the circular shaft groove 81a, and the short-circuit-bar 81 and the heat dissipation fin 82 As shown in Fig. At this time, since the insertion rib 82d can freely move within the circular shaft groove 81a, the heat dissipation fin 82 can rotate with respect to the shorting-bar 81. [ 14, when the terminal cover 83 is mounted, the fixing block 85 is fitted into the concave portion 82c, so that the rotation of the heat radiating fin 82 by the terminal cover 83 The heat dissipation fins 82 are pressed against the shorting bars 81. In this way, 15, the terminal cover 83 is fixed to the cover 12 and pressed against the heat radiating fin 82 by the fixing spring 84 (as shown in Fig. 15) And the heat radiating fins 82 are fixed.

Thus, the heat dissipation fin 82 can be rotated by 90 degrees, so that even when the direction of the power supply side terminal-load side terminal of the DC circuit breaker 102 shown in FIG. 16 is mounted in the horizontal direction, the DC circuit breaker 102 The lengthwise direction of the fin portion 82a of the heat radiating fin 82 can be set to be the vertical direction even when the direction of the power source side terminal and the load side terminal of the heat radiating fin 82 is mounted in the vertical direction, It is possible to radiate heat without generating heat.

In the present embodiment, since the concave portion 82c and the fixing block 85 are square, the heat radiating fins 82 can be fixed at 90 degrees. The shapes of the concave portion 82c and the fixing block 85 may be the same regardless of whether the shape is a square or an octagon or the like rotated 90 degrees.

According to the present embodiment, by making the shaft groove 81a circular, the heat radiating fin 82 can be rotated, and the direction of the pin can be easily changed in accordance with the mounting direction of the DC circuit breaker 102. [

Even in a situation where an impact or the like is externally applied to the DC circuit breaker 102 by the shaft groove 81a and the insertion rib 82d and the force of the fixing spring 84 temporarily weakens, The positional deviation can be prevented.

Further, by making the shapes of the fixing block 85 and the recess 82c square, the heat radiation fins can be rotated by 90 degrees.

Since the terminal cover 83 is provided with the third ventilation hole 83d at the position corresponding to the space between the pins of the pin portion 82a, the terminal cover 83 can radiate heat without generating heat retention within the terminal cover 83. [

The heat radiating fins 82 can be rotated and fixed according to the mounting direction of the DC circuit breaker 102 by fixing the terminal cover to the cover 12 so that the mounting of the DC circuit breaker 102 It is possible to allow heat dissipation independent of the direction.

10: case, 11: base,
12: cover, 12a: window hole for handle,
20: circuit breaking 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, 31: operation handle,
32: crossbar, 33: trip-bar,
40: Trip device, 50: Loop device,
51: Soho edition, 60: Barrier,
60a: exhaust hole, 61: barrier curtain,
62: buffer space, 62a: first space,
62b: second space, 70: connecting conductor unit,
71: short-bar, 72: heat dissipation pin,
72a: pin portion, 72b: base portion,
73: Terminal cover, 73a: Arc wall,
73b: first ventilation hole, 73c: second ventilation hole,
73d: third ventilation hole, 73e: ceiling surface,
74: mounting screw, 101: DC circuit breaker.

Claims (4)

A movable contact having a base, at least two fixed contacts provided on the base and having fixed contacts, movable contacts provided corresponding to the fixed contacts and having movable contacts that come into contact with and open the fixed contacts, An arc extinguishing device which is provided corresponding to the movable contact and which is formed of a so-called arc plate provided on the front end side of the movable contactor, a terminal connected to the stationary contactor, A barrier having an exhaust hole for exhausting a generated blocking gas and a barrier curtain provided on the terminal side of the barrier for blocking the exhaust hole and not blocking the exhaust hole when shut- , A short-bar which connects two adjacent terminals of the terminals, and a pin portion and a base portion which are provided in the short- The thermally activated pin and the terminal, the short-bar, and is provided with the terminal cover, the terminal cover covering the heat dissipation fin, a DC circuit breaker having an arc wall dividing between the terminal and the heat radiating fins. The method according to claim 1,
Wherein the arc wall extends from the base to the short-bar side. The method according to claim 1 or 2,
And the heat radiating fins are rotated 90 degrees around an axis provided in the short-circuiting bar. The method according to claim 1 or 2,
Wherein the terminal cover is provided with a ventilation hole at a position corresponding to a space between the pins of the heat radiation fins.

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