KR20120108660A - Gas insulated switchgear - Google Patents

Abstract

PURPOSE: A gas insulated switchgear is provided to open and close a current by individually driving a disconnector and an earthing switch using a manipulator. CONSTITUTION: An insulated switchgear(1) includes a first conductor(20) and second conductors(30). The first and second conductors are respectively connected to first and second insulators(11,12). The second conductor is arranged in the direction perpendicular to the first conductor. An earthing switch and a disconnector of a manipulator(100) are contacted to an earthing fixing point(ES1) and a connector fixing point(DS1), respectively.

Description

Gas Insulated Switchgear

The present invention relates to a gas insulated switchgear, in particular, has a compact configuration while satisfying the various requirements of the user, and to individually reduce the operation of the disconnecting device and the grounding switch to reduce the driving force and the generation of metallic foreign matter.

In general, the gas insulated switchgear is to form a certain internal space inside the case to install a breaker, but to provide sufficient extinguishing action by filling the inner space with an insulating gas, such as SF ₆ , an inert gas with excellent insulation strength. .

The gas insulated switchgear is a circuit breaker (CB) that serves to cut off a current (load current) in the event of an accident such as opening or closing a load or an earth or short circuit in a power transmission, distribution system or electric circuit, Ground switchgear to remove residual voltage and current remaining in switchgear for maintenance inspection of gas insulated switchgear, and excitation of no-load transformer Appliances such as disconnectors, which must have the capability of opening and closing current and charging current or loop current of lines or buses, are provided.

Further, the opening and closing operation of the disconnector is executed when the breaker or other switch is in a disconnected state, i.e., in a no-load current state, and is used for isolation or connection change of a circuit for checking a line or the like.

Also, the method of implementing the ground switch and disconnector as a single assembly is called a 3-position switchgear or a 3-way switchgear, and implements a mechanical interlock between the ground switch and the disconnector. .

The conventional gas insulated switchgear having a three-position switchgear connects a lever, a link, and a disconnector-ground switch mover to a rotating shaft inside the enclosure by a pin to move the disconnector-ground switch mover simultaneously. It is a structure that converts the rotational movement of the lever into the linear movement of the mover, and the force always acts at a constant angle with respect to the movement direction of the mover by the rotation of the lever.

Therefore, by simultaneously driving the disconnector-ground switch mover, even when only the operation of any part of the disconnector side or the ground switch side is required, the mover simultaneously drives the driving force according to unnecessary movement, and there is a high possibility of metal foreign matter generation. Accordingly, there is a problem that the probability of occurrence of an insulation accident increases.

Accordingly, the present invention has been made to solve the above-mentioned general problems, and an object of the present invention is to provide a compact structure by opening and closing a current by individually driving a disconnector and a ground switch through an actuator operated by one drive shaft. The present invention provides a gas insulated switchgear that can reduce the occurrence of metallic foreign matters and respond appropriately to various requirements of the user.

Solution to Problem The present invention for achieving the above object, a plurality of first conductors and a plurality of first conductors are connected to the first insulator and are arranged in the enclosure, the plurality of second conductors spaced apart from the first conductors A second insulator disposed in a direction orthogonal to the first insulator while being connected to the first insulator,

Manipulators are connected to the first conductors, and the enclosure is configured by independent compartments by first and second insulators.

A ground fixed contact is formed in the enclosure, and a disconnector fixed contact is formed on the second conductor side, so that the ground mover and the disconnector mover of the manipulator are respectively connected to the ground fixed contact and the disconnector fixed contact by the rotational movement of the insulating rod. It is characterized by what is configured to be in contact.

In addition, in the present invention, the first and second insulators are formed in parallel at intervals inside the enclosure, and a plurality of first and second conductors connected to the first and second insulators are provided, respectively. The conductors are arranged with manipulators connected,

The first conductors and the second conductors are arranged in a straight line with each other, the enclosure is composed of independent compartments by the first and second insulators,

Ground fixed contacts are formed in the enclosure, and disconnector fixed contacts are formed at the ends of the second conductors, so that the ground movers and the disconnector movers of the manipulator are rotated on an insulating rod provided with the ground fixed contacts and disconnectors. It is another technical feature to be configured to contact each of the stationary contacts.

In addition, in the present invention, the first and second insulators are arranged in parallel at intervals inside the enclosure, and a plurality of first and second conductors connected to the first and second insulators are provided, respectively. The conductors are arranged with manipulators connected,

The first conductors and the second conductors are arranged in a straight line with each other, the enclosure is composed of independent compartments by the first and second insulators,

Ground fixed contacts are formed in the enclosure, and disconnector fixed contacts are formed at ends of the second conductors so that the ground movers and the disconnector movers in the manipulator are connected to the ground fixed contacts by the rotational movement of the insulating rod. Each of which is in contact with the disconnecting stationary contacts,

Another technical feature is that the ground movable contacts are further formed on one side of the disconnector fixed contacts on the second conductors, and the ground movers are disposed to contact the ground movable contacts at intervals thereon.

In addition, the present invention is provided with the first and second insulators arranged parallel to each other at intervals inside the enclosure, the first and second conductors connected to the first and second insulators, respectively. The manipulator is arranged connected to the first conductor,

The first conductor and the second conductor are not arranged in a straight line with each other and disposed in parallel with a step,

A ground fixing contact is formed in the enclosure, and a disconnector fixing contact is formed at an end of the second conductor so that the ground mover and the disconnector mover of the manipulator are connected to the ground fixed contact and the disconnector fixed contact by a rotational movement of the insulating rod. It is another technical feature that each is configured to be in contact.

Insulation posts are supported on one side of the manipulator and one side of the second conductor, respectively.

In addition, the present invention is provided with a first conductor and a second conductor inside the enclosure, the first conductor is disposed connected to the manipulator,

The first conductor and the second conductor are not arranged in a straight line with each other and arranged in parallel with a step,

A ground fixing contact is formed in the enclosure, and a disconnector fixing contact is formed at an end of the second conductor so that the ground mover and the disconnector mover of the manipulator are connected to the ground fixed contact and the disconnector fixed contact by the rotational movement of the insulating rod. In contact with each other,

Another technical feature is that an insulating post is supported on one side of the manipulator and one side of the second conductor.

In addition, the first conductor and the second conductor have a structure connected or integrated to the manipulator and the disconnector fixed contact through the first and second conductors, respectively.

As described above, the present invention can realize the compact structure of opening and closing the current by reducing the driving force by separately driving the disconnecting device and the grounding switch through a manipulator operated by one drive shaft, and reducing the occurrence of metallic foreign substances. Therefore, insulation accident can be prevented.

In addition, the present invention implements various arrangement structures through structures such as conductors, manipulators, insulators, and insulation posts provided in the enclosure, thereby effectively responding to various needs of users.

1 is a schematic view showing a gas insulated switchgear according to an embodiment of the present invention.
Figure 2 is a schematic diagram showing a gas insulated switchgear according to another embodiment of the present invention.
Figure 3 is a schematic diagram showing a gas insulated switchgear according to another embodiment of the present invention.
Figure 4 is a schematic diagram showing a gas insulated switchgear according to another embodiment of the present invention.
5 is a schematic diagram schematically showing a gas insulated switchgear according to another embodiment of the present invention.
Fig. 6 is a plan view of Fig. 5. Fig.
7 is a perspective view illustrating a structure of a manipulator applied to the insulated switchgear of FIGS. 1 to 6.
8 is a schematic diagram showing another structure of the manipulator of FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

In describing the embodiment according to the present invention, the insulated switchgear shown in FIGS. 1 to 3 is a three-phase collective structure, and the insulated switchgear shown in FIGS. 4 and 5 and 6 is a single phase separated structure.

1 is a schematic view showing an insulated switchgear according to an embodiment of the present invention. As shown in the drawing, the insulated switchgear 1 according to an embodiment of the present invention has a three-phase collective structure and includes an enclosure ( The first conductors 20 and the second conductors 30, which are respectively connected to the first and second insulators 11, 12 arranged in the enclosure 10, are provided. Manipulators 100 to be described later are connected (or integrated) to one conductor 20 based on FIGS. 7 and 8.

A plurality of first and second conductors 20 and 30 are each connected to the first and second insulators 11 and 12 in a group (only two are shown in the drawing for convenience).

In addition, although the first and second conductors 20 and 30 connected to the first and second insulators 11 and 12 are not shown in detail, both sides of the first and second insulators 11 and 12 are shown. Each side has a structure connected to each other through a fastening member or the like.

In the embodiment according to the present invention, it turns out that the manipulator 100 has a structure of FIG.

For example, one first insulator 11 is disposed at intervals in the vertical direction, and the first conductors 20 are connected to each other, and two second insulators 12 are disposed at intervals in the horizontal direction. Two conductors 30 are connected.

In other words, the second conductors 30 are orthogonal to the first conductors 20, and the enclosure 10 is composed of separate sections by the first and second insulators 11 and 12. .

In addition, the ground fixed contact ES1 is formed in the enclosure 10, and the disconnector fixed contact DS1 is formed in the second conductor 30, so that the ground mover 700 and the disconnector mover of the manipulator 100 are formed. 600 is in contact with the ground fixed contact ES1 and the disconnector fixed contact DS1, respectively.

FIG. 8 schematically illustrates a manipulator 100 having a structure different from that of FIG. 7, similarly to FIG. 7, a disconnector fixed contact DS1 contacting the disconnector mover 600 moving in the manipulator 100 is a disconnector. (DS), and the ground mover 700 and the disconnector fixed contact DS1 form the ground breaker ES.

FIG. 2 is a schematic view showing another embodiment of the present invention, similarly to FIG. 1, having a three-phase package structure, in which the first and second insulators 11 and 12 are parallel to each other at intervals in the enclosure 10. The plurality of first conductors 20 and the second conductors 30 are connected to the first and second insulators 11 and 12, respectively.

In other words, the first and second conductors 20 and 30 connected to the first and second insulators 11 and 12 have a symmetrical structure.

In addition, the connection structure of the first conductors 20 and the second conductors 30 to the first and second insulators 11 and 12, respectively, is similar to that described with reference to FIG. And 2 are fastened and connected to both sides of the insulators 11 and 12.

In addition, in FIG. 2, the first conductors 20 and the second conductors 30 are arranged in a straight line with each other, and the enclosure 10 is a compartment separated by the first and second insulators 11 and 12. It consists of.

In addition, the manipulator 100 is connected to or integrated with the first conductor 20 as in the embodiment illustrated in FIG. 1.

In addition, the ground fixed contact ES1 is formed at the enclosure 10 side, and the disconnecting device fixed contact DS1 is formed at the end of the second conductor 30 so that the ground switch ES and the disconnecting device ES of the manipulator 100 are formed. DS is in contact with the ground fixed contact ES1 and the disconnector fixed contact DS1, respectively.

3 is a schematic view showing another embodiment of the present invention, having a three-phase package structure, similar to FIG. 2, with the first and second insulators 11 and 12 spaced apart in the enclosure 10, respectively. Are arranged in parallel, the first conductors 20 and the second conductors 30 are arranged in a straight line with each other, the enclosure 10 is composed of independent compartments by the first and second insulators 11 and 12, The manipulator 100 is connected or integrated with the first conductor 20.

In other words, the first and second conductors 20 and 30 respectively connected to the first and second insulators 11 and 12 have symmetrical structures.

In addition, in FIG. 3, the ground fixed contact ES1 is formed at the enclosure 10 side, and the disconnecting device fixed contact DS1 is formed at the end of the second conductor 30 so that the grounding operation within the manipulator 100 is performed. The ruler 700 and the disconnector mover 600 are in contact with the ground fixed contact ES1 and the disconnector fixed contact DS1 according to the operation described below with reference to FIGS. 7 and 8, respectively.

In addition, a ground movable contact ES2 is formed on one side of the disconnector fixed contact DS1 on the second conductor 30, and the ground mover 40 is disposed at an upper portion thereof with a gap therebetween.

Thus, when the ground mover 700 of the manipulator 100 is drawn out and contacts the ground fixed contact ES1, the ground is formed on the first conductor 20 side, and at this time, the ground mover 40 separately installed As a result, the second conductor 30 may be grounded by contacting the ground movable contact ES2 provided on the second conductor 30.

1 to 3, since the three-phase package structure is described, the manipulator 100 is also provided in proportion to the number of phases.

In addition, Figure 4 is a schematic diagram showing another embodiment of the present invention, having a single-phase separated structure, the first and second insulators 11, 12 are arranged in parallel to each other at intervals inside the enclosure (10). The first and second conductors 20 and 30 are connected to the first and second insulators 11 and 12, respectively.

In this case, the first conductor 20 and the second conductor 30 are not arranged in a straight line with each other, but are disposed in parallel with each other with a step.

In addition, the manipulator 100 is connected or integrated with the first conductor 20.

In addition, the grounding fixed contact ES1 is formed at the enclosure 10 side, and the disconnecting device fixed contact DS1 is formed at the end of the second conductor 30 so that the ground mover 700 and the disconnecting device of the manipulator 100 are movable. The ruler 600 is in contact with the ground fixed contact ES1 and the disconnector fixed contact DS1, respectively.

5 is a schematic view showing another embodiment of the present invention, and FIG. 6 is a plan view of FIG.

5 has a single phase separation type structure, the first conductor 20 and the second conductor 30 are arranged in parallel with each other with a step, and the manipulator 100 is connected to the first conductor 20 ( Or integrated).

However, the first conductor 20 and the second conductor 30 may be arranged without a step.

In addition, the grounding fixed contact ES1 is formed in the enclosure 10, and the disconnecting device fixed contact DS1 is formed at the end of the second conductor 30.

In addition, the first conductor 20 and the second conductor 30 do not have one long conductor when the length of the first conductor 20 and the second conductor 30 is long, and extends the length by connecting the first and second conductors 21 and 31. It has a structure provided.

In more detail, the first conductor 21 connected to the first conductor 20 is connected to the manipulator 100, and a disconnecting device fixed contact DS1 is formed at an end of the second conductor 31. It can have

In addition, the first and second conductors 20 and 30 and the first and second conductors 21 and 31 may have a structure in which the first and second conductors 20 and 30 and the first and second conductors 21 and 31 are coupled using bolts or spiral contact springs. It may have a coupling structure.

In addition, as shown in FIG. 6, an insulating post 110 is supported on one side of the manipulator 100, and an insulating rod 120 rotatable by a motor (not shown) on the opposite side of the manipulator 100. ) Is connected to the structure, and as the insulating rod 120 rotates, the drive gear 300 of the manipulator 100 described below rotates.

In addition, an insulation post 130 is also provided on the second conductor 30 side, and an insulation post 130 may be provided on the side surface of the second conductor 30 or the second conductor 31.

In other words, in the exemplary embodiment of FIG. 5, unlike the exemplary embodiment illustrated in FIGS. 1 to 4, the first and second insulators 11 and 12 are not provided, thereby reducing the cost of the apparatus. Do.

In addition, the insulating rod 120 and the insulating posts 110 and 130 may be applicable to the embodiment shown in FIGS. 1 to 4. Therefore, the ground mover 700 and the disconnector mover 600 of the manipulator 100 may contact and release the ground fixed contact ES1 and the disconnector fixed contact DS1, respectively, by the rotational movement of the insulating rod 120. It is intended to be structured.

On the other hand, Figure 7 is a perspective view showing another structure of the manipulator 100 applied to the gas insulated switchgear shown in Figures 1 to 6, as shown in the figure, the manipulator 100, the main body 200, The driving gear 300 includes a first driven gear 400, a first rack gear 420, a second driven gear 500, and a second rack gear 520.

 Opening parts 210 corresponding to the disconnecting unit DS and the ground switch ES may be formed at both sides of the main body 200, respectively. Here, the disconnecting unit (DS) side and the ground switch (ES) side opening 210 may be arranged at various angles (θ) depending on the structure within a range that does not interfere with the mechanism operation.

The drive gear 300 is a shaft 310 rotatably installed in the main body 200 in the form of a pinion gear, and an external manipulator for transmitting a driving force to the shaft 310 outside the main body 200. Not shown) is provided separately.

That is, the drive gear 300 is selectively in both directions such that the drive gear 300 is positioned in any one of the disconnector DS, the ground switch ES, or the neutral position (the position of disconnecting all connections) by the driving force of the external manipulator (not shown). Rotate

In other words, the driving gear 300 has a rotational direction determined by an operation of an external manipulator, and selectively rotates to the disconnector DS side or the ground switch ES based on the determined rotational direction.

Of course, when the disconnection of the disconnecting device (DS) and the ground switch (ES) is disconnected, the drive gear 300 is rotated to a neutral position that is not connected. Accordingly, three positions can be selected by one manipulator. As shown in FIG. 7, the first driven gear 400 is installed with the shaft 310 to rotate in engagement with the drive gear 300, and the main body 200. It is installed to be located adjacent to the disconnector (DS) side opening 210. Since the first driven gear 400 has a form of a pinion gear, the first driven gear 400 rotates in a direction opposite to the rotation direction of the drive gear 300.

The first rack gear 420 is engaged with one side of the first driven gear 400, and moves to one side according to the rotational direction of the first driven gear 400. It is connected to or disconnected from the contact. In other words, it is connected to or disconnected from the contact point of the disconnector DS through the disconnector DS side opening 210.

Here, the first rack gear 420 and the second rack gear 520 is assembled to the disconnector mover 600 and the ground mover 700 of the disconnector DS or the ground switch ES, respectively. desirable.

 On the other hand, the second driven gear 500 is installed in the shaft 310 to rotate in engagement with the drive gear 300 and the ground switch (ES) side, the opening portion (ES) side opening of the main body 200 ( 210 is installed adjacent to. That is, the second driven gear 500 is formed of the same pinion gear as the first driven gear, and rotates in the opposite direction to the rotation direction of the drive gear 300. The second rack gear 520 is engaged with one side of the second driven gear 500, and moves to one side according to the rotational direction of the second driven gear 500, and one end in the longitudinal direction of the ground switch is closed. It is connected to or disconnected from the contact.

In other words, the ground switch ES is connected to or disconnected from the contact point of the ground switch ES through the opening 210.

The first rack gear 420 and the second rack gear described as described above may be arranged at various angles θ according to the structure so that there is no mutual interference. For example, when the first rack gear 420 is installed vertically, the second rack gear 520 may be installed horizontally.

On the other hand, the above-described drive gear 300 may be integrally provided with a first guide member 320 forming a circumferential surface with a radius of rotation between the first driven gear 400 and the second driven gear 500.

In addition, one surface of the first driven gear 400 and the second driven gear 500 may have a corresponding circumferential surface so that the outer circumferential surface of the first guide member 320 may slide in one direction along the inner circumferential surface. The second guide member 410 and the third guide member 510 having protruding shapes are respectively formed.

That is, the first guide member 410 is further extended to the outside to form a circumferential surface having a larger diameter than the outside of the drive gear 300. The first guide member 320 may be any one of the second guide member 410 and the third guide member 510 according to the rotation direction (disconnector DS or ground switch ES) of the drive gear 300. Optionally guided to one.

In addition, the drive gear 300 may be formed with a cutout portion 340 positioned between the first driven gear 400 and the second driven gear 500 in a neutral position. That is, the first guide member 320 may be fixedly positioned by the connecting member 330 having a length on the shaft 310 through the cutout 340.

The first rack gear 420 and the second rack gear 520 described above are arranged so that one end of the first rack gear 420 and the second rack gear 520 are separated from the contact point of the disconnector DS and the ground switch ES when the driving gear 300 is in the neutral position. Is located.

At this time, both ends of the rotation direction (length direction) of the first guide member 320 is preferably in close contact with the inner peripheral surface of the second guide member 410 and the third guide member 510.

As described above, the manipulator 100 of the present invention drives only one of the disconnector DS and the ground breaker ES and fixes the other, so that the disconnector DS drive and the ground breaker ES drive device are respectively. Can be driven independently In addition, it is possible to maintain a neutral position to disconnect both the disconnecting device (DS) and the ground breaker (ES), it is possible to drive all three positions with one manipulator.

As a result, it is possible to drive the disconnector (DS), the grounding switch (ES) or the neutral position all with one manipulator, and the structure is simple, changing the rotational movement of the lever (LEVER) to the linear movement by the gear The independent operation of the) side and the breaker (DS) side can reduce the frequency of operation, reduce the occurrence of metal foreign substances, prevent the accident of high-voltage circuit breaker, and improve the quality.

In addition, by allowing the drive device connecting the disconnector DS and the drive device connecting the earth breaker ES to be driven independently, the input can be minimized, and either of the earth breaker ES or the disconnector DS The remaining part can be stably held by the guide member while one part is in operation.

While the invention has been described for the embodiments of the invention based on the accompanying drawings for convenience, various modifications and variations are possible without departing from the scope of the technical idea of the present invention, such variations and modifications are claims of the invention Inclusion within is self-evident.

ES: Earthing Switch
DS: Disconnector
ES1: Ground fixed contact
ES2: Ground movable contact
DS1: Disconnector Fixed Contact
1: Insulated switchgear
10: enclosure
11: first insulator
12: second insulator
20: first conductor
21: first conductor
30: second conductor
31: second conductor
40: grounding mover
100: manipulator
110: Insulation Post
120: insulated rod
200:
210: opening
300: drive gear
310: axis
320: first guide member
330: connecting member
340: incision
400: first driven gear
410: second guide member
420: first rack gear
500: 2nd driven gear
510: third guide member
520: second rack gear
600: disconnector mover
700: grounding mover

Claims (7)

A second disposed in the enclosure and connected to the plurality of first conductors and the first insulator, the second conductors being orthogonal to the first insulator while being connected to the plurality of second conductors spaced apart from the first conductors; An insulator is provided,
Manipulators are connected to the first conductors, and the enclosure is configured by independent compartments by first and second insulators.
A ground fixed contact is formed in the enclosure, and a disconnector fixed contact is formed on the second conductor side, so that the ground mover and the disconnector mover of the manipulator are respectively connected to the ground fixed contact and the disconnector fixed contact by the rotational movement of the insulating rod. Gas insulated switchgear, characterized in that configured to be in contact.
The first and second insulators are formed to be parallel to each other at intervals inside the enclosure, and a plurality of first and second conductors connected to the first and second insulators are provided, respectively. Connected and placed,
The first conductors and the second conductors are arranged in a straight line with each other, the enclosure is composed of independent compartments by the first and second insulators,
Ground fixed contacts are formed in the enclosure, and disconnector fixed contacts are formed at the ends of the second conductors, so that the ground movers and the disconnector movers of the manipulator are rotated on an insulating rod provided with the ground fixed contacts and disconnectors. Gas insulated switchgear, characterized in that configured to be in contact with each of the fixed contacts.
The first and second insulators are arranged in parallel at intervals inside the enclosure, and a plurality of first and second conductors connected to the first and second insulators are provided, respectively, and the first conductors are provided with a manipulator. Connected and placed,
The first conductors and the second conductors are arranged in a straight line with each other, the enclosure is composed of independent compartments by the first and second insulators,
Ground fixed contacts are formed in the enclosure, and disconnector fixed contacts are formed at ends of the second conductors so that the ground movers and the disconnector movers in the manipulator are connected to the ground fixed contacts by the rotational movement of the insulating rod. Each of which is in contact with the disconnecting stationary contacts,
A ground insulation contact is formed on one side of the disconnector fixed contact points on the second conductors, and a ground mover contacting the ground movable contacts at intervals is further disposed. .
The first and second insulators are arranged in parallel to the inside of the enclosure, and the first and second conductors are connected to the first and second insulators, respectively. The manipulator is arranged connected to the first conductor,
The first conductor and the second conductor are not arranged in a straight line with each other and disposed in parallel with a step,
A ground fixing contact is formed in the enclosure, and a disconnector fixing contact is formed at an end of the second conductor so that the ground mover and the disconnector mover of the manipulator are connected to the ground fixed contact and the disconnector fixed contact by a rotational movement of the insulating rod. Gas insulated switchgear, characterized in that configured to be in contact with each other.
The method according to any one of claims 1 to 4,
And an insulation post is supported on one side of the manipulator and one side of the second conductor.
A first conductor and a second conductor are provided inside the enclosure, and the first conductor is connected to the manipulator and disposed.
The first conductor and the second conductor are not arranged in a straight line with each other and arranged in parallel with a step,
A ground fixing contact is formed in the enclosure, and a disconnector fixing contact is formed at an end of the second conductor so that the ground mover and the disconnector mover of the manipulator are connected to the ground fixed contact and the disconnector fixed contact by the rotational movement of the insulating rod. In contact with each other,
Gas insulation switchgear characterized in that the insulating post is supported on one side of the manipulator and one side of the second conductor.
The method of claim 6,
And the first conductor and the second conductor are connected to or integrated with the manipulator and the disconnector fixed contact through the first and second conductors, respectively.

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