Circuit breaker with arc eliminator and power receiving/distributing equipment using same

Abstract

Power receiving/distributing equipment is composed of a switchgear incorporated for each major electric path section, wherein, when arc fault occurs on an electric path to which a circuit breaker is connected, a high-speed closing device closes to detour arc current so as to flow to a ground conductor, thereby eliminating arc at a fault electric path portion. The high-speed closing device is connected to one pole or both poles of a breaking portion of the circuit breaker, and is incorporated into an insulating support member on a corresponding pole electric path so as to be able to be drawn as a whole.

Claims

1. A circuit breaker with arc eliminator, comprising a closing device which, when an arc fault occurs on an electric path to which the circuit breaker is connected, closes to cause arc current to detour via a body ground contact provided to the circuit breaker and flow to a ground conductor, thereby eliminating arc at a fault electric path portion, wherein the closing device is connected to one pole or both poles of a breaking portion of the circuit breaker, and is incorporated into an insulating support member on a corresponding pole electric path, the closing device being assembled in a detachable manner from the insulating support member with the insulating support member formed as an insulating case-shaped component by casting or molding, the closing device configured to be replaceable after use, and the circuit breaker is formed in a drawer type as a whole.

2. The circuit breaker with arc eliminator according to claim 1, wherein the closing device is formed integrally with the insulating support member by casting.

3. The circuit breaker with arc eliminator according to claim 1, wherein in the closing device, a current-conduction connection portion with an electric path conductor portion of the circuit breaker has an insertion-type configuration, so as to allow the closing device to be replaced in a state in which the insulating support member formed as the insulating case-shaped component is fixed to the circuit breaker.

4. Power receiving/distributing equipment, comprising: a switchgear having a circuit breaker with arc eliminator incorporated therein for each of major electric path sections, the circuit breaker including a closing device which, when an arc fault occurs on an electric path to which the circuit breaker is connected, closes to cause arc current to detour via a body ground contact provided to the circuit breaker and flow to a ground conductor, thereby eliminating arc at a fault electric path portion, wherein the closing device is connected to one pole or both poles of a breaking portion of the circuit breaker, and is incorporated into an insulating support member on a corresponding pole electric path, the closing device being assembled in a detachable manner from the insulating support member with the insulating support member formed as an insulating case-shaped component by casting or molding, the closing device configured to be replaceable after use, and the circuit breaker is formed in a drawer type as a whole.

5. The power receiving/distributing equipment according to claim 4, wherein the switchgear is for a bus portion and is composed of a circuit breaker with arc eliminator of both-side type in which closing devices are connected to both poles of the breaking portion of the circuit breaker, and another switchgear is composed of a circuit breaker with arc eliminator of one-side type in which the closing device of the other switchgear is connected to one pole of the breaking portion of the circuit breaker of the other switchgear.

6. The power receiving/distributing equipment according to claim 4, wherein the switchgear is for a bus portion, and another switchgear is composed of a circuit breaker with arc eliminator of both-side type in which closing devices are connected to both poles of the breaking portion of the circuit breaker of the other switchgear.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a single-line connection diagram showing an example of power receiving/distributing equipment using a circuit breaker with arc eliminator, according to embodiment 1 of the present invention.

(2) FIG. 2 is a diagram showing a single-line-diagram symbol of a circuit breaker with arc eliminator (one-side type) according to embodiment 1 of the present invention.

(3) FIG. 3 is a structure conceptual diagram of the circuit breaker with arc eliminator (one-side type) according to embodiment 1 of the present invention.

(4) FIG. 4 is a diagram showing a single-line-diagram symbol of a circuit breaker with arc eliminator (both-side type) according to embodiment 1 of the present invention.

(5) FIG. 5 is a structure conceptual diagram of the circuit breaker with arc eliminator (both-side type) according to embodiment 1 of the present invention.

(6) FIG. 6 is a single-line connection diagram showing an example of power receiving/distributing equipment using a circuit breaker with arc eliminator, according to embodiment 2 of the present invention.

(7) FIG. 7 is a diagram showing a single-line-diagram symbol of a circuit breaker with arc eliminator (one-side type) according to embodiment 2 of the present invention.

(8) FIG. 8 is a structure conceptual diagram of the circuit breaker with arc eliminator (one-side type) according to embodiment 2 of the present invention.

(9) FIG. 9 is a diagram showing a single-line-diagram symbol of a circuit breaker with arc eliminator (both-side type) according to embodiment 2 of the present invention.

(10) FIG. 10 is a structure conceptual diagram of the circuit breaker with arc eliminator (both-side type) according to embodiment 2 of the present invention.

DESCRIPTION OF EMBODIMENTS

Embodiment 1

(11) FIG. 1 is a single-line connection diagram showing an example of a circuit breaker with arc eliminator and power receiving/distributing equipment using the same, according to embodiment 1 for carrying out the present invention, and more specifically, a single-line connection diagram showing a power distribution circuit example on the secondary side of a transformer.

(12) In FIG. 1, 2 denotes a circuit breaker with arc eliminator (one-side type) in which a high-speed closing device for arc eliminator is mounted on one side of the breaking point of the circuit breaker so that an arc eliminator can be provided on three-phase electric paths from a transformer 1 to the breaking point of the circuit breaker. 200 denotes a switchgear on which the circuit breaker 2 with arc eliminator is mounted such that the circuit breaker 2 with arc eliminator can be inserted and detached. 3 denotes a circuit breaker with arc eliminator (both-side type) in which high-speed closing devices for arc eliminator are provided on both sides of the breaking point of the circuit breaker so that arc eliminators can be provided on three-phase electric paths on both sides of the breaking point of the circuit breaker. 300 denotes a switchgear on which the circuit breaker 3 with arc eliminator is mounted such that the circuit breaker 3 with arc eliminator can be inserted and detached. 4 denotes a circuit breaker with arc eliminator (one-side type) in which a high-speed closing device for arc eliminator is mounted on one side of the breaking point of the circuit breaker so that an arc eliminator can be provided on three-phase electric paths from the breaking point of the circuit breaker to the load side. 400 denotes a switchgear on which the circuit breaker 4 with arc eliminator is mounted such that the circuit breaker 4 with arc eliminator can be inserted and detached.

(13) FIG. 2 is a single-line-diagram symbol indicating the circuit breaker 2 with arc eliminator (one-side type). FIG. 3 is a structure conceptual diagram of the circuit breaker 2 with arc eliminator (one-side type).

(14) In FIG. 2 and FIG. 3, 2a denotes a breaking portion, 2a1 denotes an inter-pole insulator of the breaking portion, and 2b denotes a high-speed closing device, as disclosed in, for example, Patent Document 1. The device is downsized by vacuum insulation technology exhibiting high insulation performance, and has dimensions corresponding to the insulation distance in the atmosphere. 2b1 denotes an insulator of the high-speed closing device, which is formed integrally with the high-speed closing device 2b by casting insulation, whereby electric path portions of the circuit breaker 2 such as the breaking portion 2a, the inter-pole insulator 2a1 thereof, and an insertion contact conductor 2d are insulated and strength for mechanically supporting them is ensured. As the casting insulation material, in view of mechanical strength and an electric property, a thermosetting resin such as epoxy resin is used. However, another resin or thermoplastic resin may be used. Instead of integrally forming the high-speed closing device 2b and the insulator 2b1 by casting, the insulator 2b1 for the high-speed closing device 2b may be formed as an insulating case-shaped component by casing or molding, and the high-speed closing device 2b may be attached to the inside thereof in a detachable manner. In this case, in replacement after operation of the high-speed closing device, only the high-speed closing device 2b needs to be replaced, and thus there is an advantage that the insulator 2b1 can be used again. In the case of integral casting as shown in Non-Patent Document 1, the structure is simple, but it is necessary to integrally replace and discard the high-speed closing device 2b and the insulator 2b1.

(15) One side of the high-speed closing device 2b is electrically and mechanically connected by a fastening member such as a bolt to the electric path conductor 2d (in FIG. 3, on the lower side) connected to one pole of the breaking portion 2a. The other side of the high-speed closing device 2b is a ground conductor circuit 2c and is connected to a body ground contact 2c1 of the circuit breaker 2 with arc eliminator so that fault current is conducted from a ground conductor 2c3 of the switchgear to the ground through a ground terminal 2c2 provided to a circuit breaker compartment of the switchgear. The ground conductor circuit 2c (2c1, 2c2, 2c3) has a current-conduction capacity for short-time conduction current and current-conduction time that are compliant with the standard of switchgear or circuit breaker such as IEC (International Electrotechnical Commission), and is connected to the high-speed closing device 2b by attachable/detachable fastening means such as a bolt. Here, 2c1 and 2c2 are formed as sliding contacts.

(16) When arc fault occurs on an electric path connected to the circuit breaker 2, the high-speed closing device 2b closes to detour the arc current to flow to the ground conductor circuit 2c, thereby eliminating the arc at the fault electric path part, and thus the high-speed closing device 2b needs to be replaced per one closing operation.

(17) 2e denotes a support insulating member which electrically and mechanically supports the other pole of the breaking portion 2b and the electric path conductor (in FIG. 3, on the upper side) 2d connected to the other pole. The outer shape and the attachment structure of the support insulating member 2e are the same as the dimensions and the attachment structure of the insulator 2b1 of the high-speed closing device. The ends (in FIG. 3, right ends) of the upper and lower electric path conductors 2d are, for example, tulip contacts configured to be able to be inserted and detached with respect to electric path terminals (not shown) of the switchgear. 2f denotes wheels provided for facilitating movement of the circuit breaker 2 with arc eliminator inside the switchgear 200 or the like.

(18) Although not shown, a circuit breaker with arc eliminator (one-side type) in which a high-speed closing device is provided to the electric path conductor (in FIG. 3, on the upper side) connected to the other pole of the breaking portion can also be formed by only reassembling members and adding a ground-side conductor, and thus can be selected as appropriate in accordance with the configuration of the power receiving/distributing equipment.

(19) FIG. 4 is a single-line-diagram symbol showing a circuit breaker 3 with arc eliminator (both-side type). FIG. 5 is a structure conceptual diagram of the circuit breaker 3 with arc eliminator (both-side type).

(20) This circuit breaker 3 with arc eliminator is a both-pole type in which high-speed closing devices 3b are provided at both poles of a breaking portion 3a. The configuration of each part is the same as that of the one-side type described in FIG. 2 and FIG. 3, and the description thereof is omitted.

(21) Next, application of the circuit breaker with arc eliminator will be described.

(22) On the assumption in which, by any possibility, arc fault will occur in the power receiving/distributing equipment, a power receiving/distributing equipment plan is made so as to maximize the operation rate of the power receiving/distributing equipment until recovery from the fault. In this case, in order to minimize the power stop range and minimize the power stop period including equipment recovery work after fault when the electric path portion where occurrence of arc fault is assumed, and the corresponding electric path section, are separated from the other normal electric paths, it is necessary to make a plan for placing the switchgear 1, considering the part where a general high-speed closing device of an individual attachment type is to be placed, and considering the space and the attachment structure for placing the high-speed closing device.

(23) However, by using the circuit breaker with arc eliminator according to the present invention, it becomes possible to provide high-speed closing devices for all the electric paths of the switchgear by only selecting the circuit breaker with arc eliminator. In the case of making a perfect plan, by applying the circuit breakers with arc eliminator to all the circuit breakers, the high-speed closing devices for arc eliminator can be provided for all the electric paths without omission.

(24) In the case of adding an arc eliminator function to the power receiving/distributing equipment that does not have an arc eliminator function for the purpose of reducing damage upon fault and minimizing running loss, it is only necessary to replace each circuit breaker with the circuit breaker with arc eliminator.

(25) Next, the case where fault occurs in the power receiving/distributing equipment will be described.

(26) When arc fault (indicated by F1) occurs on an electric path in the switchgear 400 for feeder in FIG. 1, a protection system works so that a protection relay (not shown) and an arc detection device (not shown) operate to transmit a drive signal to the circuit breaker 4 with arc eliminator on the electric path, thereby separating the electric path in the fault section, and thus localizing and minimizing damage.

(27) In a general protection system using a protection relay, a period of about 100 milliseconds at earliest elapses from occurrence of fault until the relevant circuit breaker operates to separate the fault section. In the case where large fault current flows in a circuit of the equipment having a large equipment capacity and a small fault impedance, arc energy due to the arc fault is great, and therefore, even if the fault continues during only about 100 milliseconds or even if the switchgear has such an internal arc proof structure as to allow pressure release to be performed in about ten and several milliseconds after the occurrence of fault, due to explosive increase in the pressure in the switchgear compartment, melting and evaporation of metal materials composing conductors and the compartment, burning and evaporation of insulating materials, and the like, significant damage is caused to, as well as this switchgear compartment, the adjacent switchgear compartments, the adjacent devices, and the like. However, the arc eliminator function is provided which, by operating the high-speed closing device by the arc detection device, grounds the electric path on which the fault occurs, in several milliseconds after the occurrence of arc fault, and detours the fault current to the ground circuit, thereby eliminating the fault arc, thus achieving such a switchgear that is hardly damaged even after the fault has finished.

(28) Since it is desirable that the operation of the high-speed closing device at this time should be as quick as possible, simple structure performance that allows only one operation is used in order to achieve downsizing and high-speed operation. Therefore, the high-speed closing device 2b is to be replaced with new one after the fault is eliminated.

(29) Since the power receiving/distributing equipment using the circuit breaker with arc eliminator according to the present invention is configured as described above, on the assumption that arc fault will occur in the power receiving/distributing equipment by any possibility, it is possible to simply and easily perform design in equipment planning for minimizing running loss in that case. In addition, it is possible to perform, in a simple manner and at low cost, modification for adding the arc eliminator function to the existing equipment. Thus, an effect of shortening the power stop period due to the equipment modification and reducing the modification cost is obtained.

(30) Further, it is possible to easily provide the arc eliminator function with fine mesh on the entire electric paths in the power receiving/distributing equipment, without enlarging the size of the equipment.

(31) In addition, replacement work after the high-speed closing device has operated due to occurrence of arc fault can be easily performed, and equipment recovery can be swiftly performed after the arc fault has been eliminated. Therefore, the power stop period is shortened and running loss is reduced.

(32) Here, the case where the high-speed closing device is replaced per one operation has been shown as an example. In this case, since the replacement will be performed at a high frequency, the effect of the present embodiment can be exerted to the maximum extent. However, as a matter of course, even in the case where it is not necessary to replace the high-speed closing device per one operation, for example, the case where the high-speed closing device is to be replaced per two operations or three or more operations, the effect of the present embodiment can be obtained.

Embodiment 2

(33) FIG. 6 to FIG. 10 show a circuit breaker with arc eliminator and power receiving/distributing equipment using the same, according to embodiment 2.

(34) FIG. 6 is a single-line connection diagram showing an example of the circuit breaker with arc eliminator and the power receiving/distributing equipment using the same, according to embodiment 2 for carrying out the present invention. As shown in FIG. 7 to FIG. 10, circuit breakers 20, 30, 40 with arc eliminator according to embodiment 2 are circuit breakers with arc eliminator of a type in which the high-speed closing device is inserted, and thus are a modified type so that only the high-speed closing device portion which needs to be replaced after operation upon arc fault can be mounted and detached with respect to the circuit breaker body.

(35) 20g in FIG. 8 denotes an insertion contact portion, which forms an insertion-type contact structure in which a lower electric path 20d of the circuit breaker 20 and a high-speed closing device 20b are attachable and detachable with each other as in, for example, a tulip contact. In this case, an insulator 20b1 for the high-speed closing device is formed as a cast or molded product having a case shape, instead of being integrated with the high-speed closing device 20b by casting.

(36) An insertion contact portion 30g in FIG. 9 also has the same structure as the insertion contact portion 20g, and forms an insertion-type contact structure that allows attachment and detachment as in a tulip contact or the like. The other configuration is the same as that described in embodiment 1.

(37) In the present embodiment 2, as compared to embodiment 1, recovery work is further facilitated, so that the power stop period for recovery is further shortened, thus providing an effect of further reducing running loss.

Embodiment 3

(38) In the circuit breaker with arc eliminator and the power receiving/distributing equipment using the same as described in embodiment 1 and embodiment 2, the circuit breaker with arc eliminator (one-side type) and the circuit breaker with arc eliminator (both-side type) are selectively used in accordance with the electric path sections. However, all the circuit breakers may be the circuit breakers with arc eliminator (both-side type). In this case, equipment planning is further facilitated, and if the high-speed closing device at the bus portion (in FIG. 1 or FIG. 6 shown as an example, there is only one high-speed closing device for bus) has operated, another feeder circuit breaker can be used as substitute. Thus, recovery from fault is further facilitated, and an effect of shortening the power stop period in recovery is provided.

(39) It is noted that, within the scope of the present invention, the above embodiments may be freely combined in part or whole, or each of the above embodiments may be modified or simplified as appropriate.

DESCRIPTION OF THE REFERENCE CHARACTERS

(40) 1 transformer 2 circuit breaker with arc eliminator (one-side type) 2a, 3a, 20a, 30a breaking portion 2a1, 3a1, 20a1, 30a1 inter-pole insulator of breaking portion 2b, 3b, 20b, 30b high-speed closing device 2b1, 3b1, 20b1, 30b1 insulating support member for high-speed closing device 2c, 3c, 20c, 30c ground conductor circuit 2c1, 3c1, 20c1, 30c1 ground contact 2c2, 3c2, 20c2, 30c2 ground terminal conductor (switchgear attachment) 2c3, 3c3, 20c3, 30c3 ground conductor (switchgear attachment) 2d, 3d, 20d, 30d electric path conductor 2e, 3e, 20e, 30e support insulating member 2f, 3f, 20f, 30f wheel 3 circuit breaker with arc eliminator (both-side type) 4 circuit breaker with arc eliminator (one-side type) 200, 300, 400 switchgear 20 insertion-type circuit breaker with arc eliminator (one-side type) 30 insertion-type circuit breaker with arc eliminator (both-side type) 20g, 30g insertion contact portion