WO2018212210A1

WO2018212210A1 - Breaker and switch gear

Info

Publication number: WO2018212210A1
Application number: PCT/JP2018/018847
Authority: WO
Inventors: 進小鶴; 堀之内　克彦
Original assignee: 三菱電機株式会社
Priority date: 2017-05-17
Filing date: 2018-05-16
Publication date: 2018-11-22
Also published as: DE112018002541T5; JP6714948B2; JPWO2018212210A1

Abstract

When a 3-phase AC current is passed through a breaker, the effects of radiation and convection from the conductor surface varies according to the conductor, increasing the cost of heat dissipation design. Therefore, the present invention is provided with: electrical path conductors (2a, 3a, 4a) of three phases; breaking units (100) provided to each of the electrical path conductors of three phases, the breaking units (100) cutting off a current flowing when a short circuit occurs; and a high-speed grounding device (102) connected in order to ground the breaking units (100) when a short circuit occurs. The electrical path conductors are disposed so that the distance therebetween varies.

Description

Circuit breaker and switchgear

The present application relates to a circuit breaker and a switch gear, and more particularly to an arrangement structure of conductors housed in the circuit breaker and the switch gear.

・ Low-voltage, medium-voltage, or high-voltage power distribution facilities are indispensable equipment systems such as buildings and factories as a social infrastructure for power supply and demand. The safety and reliability are fully considered not only for manufacturers but also for installation work and general operation and maintenance. However, a fault such as a ground fault or a short circuit may occur due to the insulation function of the electric circuit being impaired due to the invasion of small animals or foreign objects, insulation deterioration due to aging, or equipment damage due to earthquakes. Particularly in the case of an internal short circuit of a closing device such as a switchgear, a large current arc is generated, and the vicinity of the arc becomes a plasma state of about 10,000 to 20,000 degrees. Therefore, the surrounding metal and the insulator are partially vaporized, and the insulating gas such as air around the arc expands instantaneously and the inside of the apparatus becomes extremely high pressure. Since the switchgear in which an internal short-circuit accompanied by such an arc has occurred is severely damaged, in recent years, the arc is eliminated by grounding the three-phase circuit within a few milliseconds after the occurrence of the internal short-circuit. A circuit breaker with a grounding device that suppresses the influence of a short circuit is disclosed (see, for example, Patent Document 1).

International Publication No. WO2015 / 178160

In the circuit breaker shown in Patent Document 1, the conductors that are three-phase electric paths are usually arranged at equal intervals, and the conductor located in the middle is arranged from the conductor surface when a three-phase alternating current is applied. The temperature rise is the highest compared to the other two phases due to the radiation and convection effects. Therefore, it is necessary to perform a heat dissipation design that suppresses the temperature rise of the conductor.
This application is for solving such a problem, and it aims at providing the circuit breaker which can suppress the influence from the radiation | emission from a conductor surface, and a convection.

The circuit breaker disclosed in this application is
Provided in each of the three-phase circuit conductors, each of the three-phase circuit conductors, and a high-speed grounding input device that is connected to ground the interrupting part in the case of a short circuit, the interrupting part that interrupts the current flowing in the event of a short circuit,
The distance between the first phase and second phase circuit conductors is Lrs,
The distance between the second and third phase circuit conductors is Lst,
The distance between the third phase and the first phase circuit conductor is Ltr,
The distance between the first phase circuit conductor and the ground metal is Lre,
The distance between the second phase circuit conductor and the ground metal is Lse,
The distance from the third phase circuit conductor to the ground metal is Lte,
When
Lrs> Ltr
Lst> Ltr
Ltr> Lre
Ltr> Lse
Ltr> Lte
The three-phase circuit conductors are disposed so that the high-speed grounding device is provided in the first-phase circuit conductor and the third-phase circuit conductor.

According to the circuit breaker disclosed in the present application, it is possible to suppress the influence of convection and radiation when energizing current generated by the proximity of the conductor, and the cost of heat dissipation design of the circuit breaker. Become. In addition, the number of high-speed ground input devices can be reduced, and the reliability when operating the high-speed ground input device is improved.

It is a perspective view of the circuit breaker of Embodiment 1. It is a structure conceptual diagram of the circuit breaker of Embodiment 1. It is a single line connection figure which shows the circuit breaker of Embodiment 1. FIG. It is explanatory drawing explaining the arrangement | positioning of the three-phase conductor in the circuit breaker of Embodiment 1. FIG. FIG. 4 is a structural conceptual diagram of a switchgear according to a second embodiment.

Embodiment 1 FIG.
1 is a perspective view of the circuit breaker according to the first embodiment, FIG. 2 is a conceptual diagram of the structure of the circuit breaker (both sides) according to the first embodiment, and FIG. 3 is a single line connection showing the circuit breaker according to the first embodiment. 4 and 4 are explanatory diagrams for explaining the arrangement of the three-phase conductors in the circuit breaker according to the first embodiment. In the description of the first embodiment, the names of the three phases are R phase, S phase, and T phase.
1 and FIG. 2, a breaker 100, an interelectrode insulator 101, a high-speed ground input device 102, and an insulator 103 of a high-speed ground input device are disposed inside the circuit breaker 1. The insulator 103 is cast-insulated integrally with the high-speed grounding thrower 102, or a high-speed grounding thrower is assembled in its interior as an insulating case-like part produced by casting or molding, and is detachable. May be.

The high-speed ground thrower 102 is a plug-in thrower provided with a plug contact portion 102c, and has a structure in which a portion that needs to be replaced after the operation at the time of arc generation can be detached from the breaker body. One end portion 102b of the high-speed grounding input device 102 is electrically and mechanically fastened with a fastening member such as a bolt to the end portion of the R-phase circuit conductor 2b connected to the pole 100a on one side of the interrupting portion 100. . The other end of the R-phase circuit conductor 2b is a contact 20b having an insertion contact structure. The other end 102a of the high-speed earthing device 102 is a grounding conductor circuit 104 which is connected to the main body grounding contact 104a of the circuit breaker 1 and via a grounding terminal 104b provided in the circuit breaker chamber of the switchgear. A short-circuit current is applied from the ground conductor 104c of the switch gear to the ground. The grounding conductor circuit 104, the main body grounding contact 104a, the grounding terminal 104b, and the grounding conductor 104c have a short-time energization current and energization time according to switchgear standards such as IEC (International Electrotechnical Commission) and circuit breakers. The high-speed grounding input device 102 is fastened by fastening means such as bolts that can be attached and detached. However, the main body ground contact 104a and the ground terminal 104b are in sliding contact.

In addition, one end 105b of the high-speed earthing device 105 is electrically and mechanically fastened by a fastening member such as a bolt and an R-phase circuit conductor 2a that is connected to the pole 100b on the other side of the breaker 100. Yes. The other end portion 105 a is connected to the main body ground contact 104 a of the circuit breaker 1 by a ground conductor circuit 104 and is configured in the same manner as the high-speed ground input device 102. The blocking unit 100 is disposed in a vacuum and is usually called a vacuum valve.
When the arc is generated in the electric circuit to which the circuit breaker 1 is connected, the high-speed

ground input devices

102 and 105 configured as described above are turned on to bypass the arc current and flow to the ground conductor circuit 104 to extinguish the arc. The circuit breaker 1 includes wheels 106 and can be pulled out from the operating position to the disconnect position within the switch gear.

As shown in the single-line connection diagram of the circuit breaker of FIG. 3, the high-speed grounding device 102 is disposed on the R-

phase circuit conductors

2b and 2a, and the T-

phase circuit conductors

4a and 4b are also grounded at high speed. A thrower is placed. However, a high-speed grounding device is not disposed on the S-

phase circuit conductors

3a and 3b. Next, the arrangement of the R-phase, T-phase, and S-phase circuit conductors in the circuit breaker will be described with reference to FIG.
In FIG.
The distance between the circuit conductors of the R-phase circuit conductor 2b and the S-phase circuit conductor 3b is Lrs,
The distance between the circuit conductors of the S-phase circuit conductor 3b and the T-phase circuit conductor 4b is Lst,
The distance between the circuit conductors of the T-phase circuit conductor 4b and the R-phase circuit conductor 2b is Ltr,
The distance between the R-phase circuit conductor 2b and the ground metal is Lre,
The distance between the S-phase circuit conductor 3b and the ground metal is Lse,
When the distance between the T-phase circuit conductor 4b and the ground metal is Lte,
Lrs> Ltr
Lst> Ltr
Ltr> Lre
Ltr> Lse
Ltr> Lte
The R-phase circuit conductor 2b, the S-phase circuit conductor 3b, and the T-phase circuit conductor 4b are arranged so that That is, when the insulation strength between the TR phases is the weakest among the insulation strength between the RS phases, the insulation strength between the ST phases, and the insulation strength between the TR phases, and a short circuit occurs between the phases. In addition, it is possible to prevent the arc generated when the TR phase is short-circuited from reaching the S phase and causing a three-phase short circuit of the R-ST phase. In general, the energy of the two-phase short circuit is 87% of that of the three-phase short circuit. Here, the ground metal refers to the casing of the circuit breaker 1, but may be a metal case, a metal plate, a metal cover, or the like connected to the ground shielding the circuit conductor.

In the three-phase AC voltage,

Because of the relationship
Ltr> √3 × Lre
Ltr> √3 × Lse
Ltr> √3 × Lte
Then, the R-phase circuit conductor 2b and the ground metal, and the S-phase circuit conductor 3b and the ground metal, rather than the short circuit between the R-S phase, the S-T phase, or the T-R phase circuit conductor. Since there is a high possibility that a ground fault will occur between or between the T-phase circuit conductor 4b and the ground metal, it is possible to reduce the influence on other devices when a short circuit occurs. In general, the ground fault energy is smaller than the inter-phase short-circuit energy.

In addition, since the electric conductors with low insulation strength between the TR phases are arranged, as described in FIG. 3, the high-

speed grounding devices

102 and 105 are attached to the R-phase electric conductor 2b and the T-phase electric conductor 4b. Even if a short circuit between the circuit conductors occurs, the configuration of the circuit conductor is such that only the short circuit between the T-phase and the R-phase is required, so that a high-speed grounding input device for three phases is unnecessary, and the cost can be reduced.

Furthermore, if the failure rate of the high speed grounding insertion unit mounted on one phase and p, failure rate P ₃ when fitted with a high-speed ground insertion unit in all three phases of the path conductors,
P ₃ = 1- (1-p) ³
Become whereas, failure rate P ₂ of the high speed grounding insertion unit mounted only path conductors of two phases,
P ₂ = 1- (1-p) ²
It becomes. As a result, if the failure rate p of the high-speed grounding device is constant, the failure rate can be suppressed and the reliability can be improved by attaching the high-speed grounding device only to the two-phase circuit conductor.

In addition, arrangement | positioning of the electrical path conductor shown in FIG. 4 shows an example, and is not limited to the arrangement configuration of a figure. In FIG. 4, the arrangement between the

circuit conductors

2 b, 3 b, 4 b of one phase of the both-side circuit breaker has been described, but the same arrangement configuration is applied to the

circuit conductors

2 a, 3 a, 4 a of the other phase. You may design. Normally, as described above, since the temperature rise of the S-phase circuit conductor is the highest, the S-phase circuit conductor is kept away from the T-phase and R-phase circuit conductors, and Ltr is minimized. If there is a margin in the temperature rise of the S-phase circuit conductor,
(1) Lrs is minimized and high-speed grounding devices are installed on the R-phase and S-phase circuit conductors.
(2) Lst is minimized and a high-speed grounding device is installed on the S-phase and T-phase circuit conductors.
It is also good.

Embodiment 2. FIG.
FIG. 5 is a conceptual diagram of the structure of the switchgear according to the second embodiment, where (a) is a front view and (b) is a side cross-sectional view.
The internal configuration of the switch gear 1000 will be described with reference to FIG. The interior of the ground metal casing 6 is partitioned into a plurality of compartments. The circuit breaker compartment 7 houses the circuit breaker 1 described in the first embodiment, and the circuit breaker 1 can be pulled out from the front side. On the rear wall of the circuit breaker compartment 7,

disconnections

8a and 8b of the main circuit are fixedly provided at a predetermined interval in the vertical direction. The upper left part of the circuit breaker compartment 7 is a control device compartment 9 in which a control device (not shown) is accommodated.

On the back side of the circuit breaker compartment 7 is a bus compartment 12 in which a three-phase bus 10 is supported by a support insulator 11 and is provided with a disconnection portion 8a and a bus 10 connected to one end of the circuit breaker. Are connected to and stored in a branch conductor 13 made up of an R-phase branch conductor 13R, an S-phase branch conductor 13S, and a T-phase branch conductor 13T. As in the first embodiment,
L ₁ rs is the distance between the conductors of the R-phase branch conductor 13R and the S-phase branch conductor 13S.
The distance between the conductors of the S-phase branch conductor 13S and the T-phase branch conductor 13T is L ₁ st,
When the distance between the conductors of the T-phase branch conductor 13T and the R-phase branch conductor 13R is L ₁ tr,
L ₁ rs> L ₁ tr
L ₁ st> L ₁ tr
The R-phase and T-phase branch conductors are connected to a high-speed ground input device 14 disposed above the bus compartment 12.

Behind the bus compartment 12 is a cable compartment 18 in which the load-side cable 15 is accommodated. The load side conductor 16 is also accommodated in the cable compartment 18. The load side conductor 16 includes an R phase load side conductor 16R, an S phase load side conductor 16S, and a T phase load side conductor 16T. As in the first embodiment,
The distance between the conductors of the R-phase load-side conductor 16R and the S-phase load-side conductor 16S is L ₂ rs,
The distance between the conductors of the S-phase load-side conductor 16S and the T-phase load-side conductor 16T is L ₂ st,
When the distance between the conductors of the T-phase load side conductor 16T and the R-phase load side conductor 16R is L ₂ tr,
L ₂ rs> L ₂ tr
L ₂ st> L ₂ tr
It is arranged so that.

The disconnecting portion 8b connected to the other end of the circuit breaker 1 and the cable 15 are provided with an R-phase load-side conductor 16R and a T-phase load-side conductor 16T via a current transformer 17 in the middle. The S-phase load-side conductor 16 </ b> S is directly connected to the cable 15 without going through the current transformer 17. The cable 15 is pulled out of the switchgear 1000 and connected to another power device.
Thus, as in the first embodiment, the arrangement of the branch conductors and load conductors of each phase is configured such that the distance between the S-phase conductor and the other-phase (R-phase, T-phase) conductor is increased. Therefore, the effects of convection and radiation when energizing current, which occur when the conductors of the R and S phases and between the conductors of the S and T phases are close to each other, are suppressed, and a heat dissipation structure as a switchgear is achieved. It becomes possible to make it cheaper.

Note that the internal configuration of the switchgear 1000 shown in FIG. 5 is an example, and is not limited to the arrangement shown in the figure. In FIG. 5, the circuit breaker compartment 7 that houses the circuit breaker 1, the bus compartment 12, the cable compartment 18, and the control equipment compartment 9 may be provided, but the cable compartment 18 may not be provided, and other configurations may be used.

Although this application describes various exemplary embodiments and examples, various features, aspects, and functions described in one or more embodiments may be applied to particular embodiments. The present invention is not limited to this, and can be applied to the embodiments alone or in various combinations.
Accordingly, countless variations that are not illustrated are envisaged within the scope of the technology disclosed herein. For example, the case where at least one component is deformed, the case where the component is added or omitted, the case where the at least one component is extracted and combined with the component of another embodiment are included.

1: Circuit breaker, 2a, 2b: R-phase circuit conductor, 3a, 3b: S-phase circuit conductor, 4a, 4b: T-phase circuit conductor, 6: Housing, 7: Breaker compartment, 8a, 8b: Disconnection part, 9: Control equipment compartment, 10: Busbar, 11: Support insulator, 12: Busbar compartment, 13: Branch conductor, 14: High-speed grounding device, 15: Cable, 16: Load side conductor, 17: Current transformer , 18: cable compartment, 100: breaker, 101: interelectrode insulator, 102, 105: high-speed grounding device, 103: insulator, 104: ground conductor circuit, 106: wheel, 1000: switchgear

Claims

Provided in each of the three-phase electric circuit conductor, the three-phase electric circuit conductor, a blocking part that cuts off a current that flows during a short circuit, and a high-speed grounding input device that is connected to ground the blocking part during the short circuit,
The distance between the first phase and second phase circuit conductors is Lrs,
The distance between the second and third phase circuit conductors is Lst,
The distance between the third phase and the first phase circuit conductor is Ltr,
The distance between the first phase circuit conductor and the ground metal is Lre,
The distance between the second phase circuit conductor and the ground metal is Lse,
The distance from the third phase circuit conductor to the ground metal is Lte,
When
Lrs> Ltr
Lst> Ltr
Ltr> Lre
Ltr> Lse
Ltr> Lte
The three-phase circuit conductors are arranged so that the high-speed grounding thrower is provided in the first-phase circuit conductor and the third-phase circuit conductor. Circuit breaker to do.
The circuit breaker of claim 1,
Ltr> √3 × Lre
Ltr> √3 × Lse
Ltr> √3 × Lte
Circuit breaker characterized by being.
A circuit breaker that cuts off a current that flows in the case of a short circuit, a three-phase branch conductor that connects the breaker and a bus, and a high-speed ground input device that is connected to the branch conductor and connected to ground the branch conductor in the case of a short circuit Prepared,
Let L 1 rs be the distance between the branch conductors of the first phase and the second phase,
Let L 1 st be the distance between the second and third phase branch conductors,
Let L 1 tr be the distance between the branch conductors of the third phase and the first phase,
When
L 1 rs> L 1 tr
L 1 st> L 1 tr
The three-phase branch conductors are arranged so that the high-speed grounding thrower is provided in the first-phase branch conductor and the third-phase branch conductor. Switch gear to play.
A circuit breaker that interrupts a current that flows during a short circuit, a load-side conductor of three phases that connects the circuit breaker and a load;
The distance between the load-side conductors of the first phase and the second phase is L 2 rs,
The distance between the load side conductors of the second phase and the third phase is L 2 st,
The distance between the load-side conductors of the third phase and the first phase is L 2 tr,
When
L 2 rs> L 2 tr
L 2 st> L 2 tr
The three-phase load-side conductors are arranged so that the first-phase load-side conductors and the third-phase load-side conductors are connected to a current transformer. And switchgear.