KR101881573B1 - Sensor for measuring of electric power - Google Patents

Abstract

A power measurement sensor according to an embodiment of the present invention includes a power line for supplying power, partition parts of a plurality of folds, located outside the power line, and a coil which is located outside the partition parts of a plurality of folds and transmits a current flowing in the power line to the outside through the current induced by a magnetic field radiated from the power line. Each partition part of a plurality of folds is intermittently located on a virtual closed curve surrounding the power line and includes two or more partitions shielding an electric field radiated in a direction toward an arc of the power line from a center axis of the power line. Accordingly, the present invention can prevent the reduction of current measurement accuracy.

Description

SENSOR FOR MEASURING OF ELECTRIC POWER

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power measurement sensor, and more particularly, to a power measurement sensor that measures a current of power supplied through a power line.

In the case of a power generator, it may be important to deliver maximum power to a load that consumes power. To this end, impedance matching between the power generator and the load consuming power may be important. When the power consuming load includes the plasma processing chamber, it may not be simple to deliver maximum power to such a load because the conditions of the load change in real time. There is thus a need for an impedance matcher that can match impedances that vary in real time in the plasma processing chamber.

Figure 1 is a diagram of a typical plasma system for measuring input power and transferring maximum power to a plasma processing chamber through impedance matching.

Referring to Figure 1, a plasma system 101 may include an impedance matcher 120 between a plasma process chamber 110 and a power source 130 to match an impedance that varies in real time in a plasma process chamber 110 have. The impedance matcher 120 may include a sensing unit 122, an impedance matching unit 124, and a controller 126 as shown in FIG.

When power is applied from the power supply 130 to the plasma system 101, the applied power may pass through the impedance matcher 120 before reaching the plasma processing chamber 110.

First, the voltage and current of the applied power can be measured through the sensing unit 122, and a control signal for impedance matching is generated from the control unit 126 referring to the voltage and current measured from the sensing unit 122 .

Thereafter, the impedance matching unit 124 receives the control signal generated from the control unit 126 and adjusts the capacitor and the inductor value to implement the impedance matching. An implementation of the impedance matching may be to supply the maximum power to the plasma processing chamber 110.

2 is a view showing a sensing unit through a general coaxial cable.

Here, the coaxial cable includes a cover 210 provided on the outer side, an outer core 220 having a certain thickness of a cylindrical structure, an inner core 240 having a certain radius a at the center thereof And an insulator 230 may be provided between the outer core 220 and the inner core 240.

These coaxial cables are less attenu- ated to high frequencies and thus may be suitable for broadband transmission. In general, polyethylene may be filled as the insulator 230, but in the case of thick coaxial cables, a disk-shaped spacer may be inserted. Further, in the case of a coaxial cable used in a high temperature environment, Teflon can be charged.

The sensing part applied to a general coaxial cable is such that an insulator 230 is disposed between the inner core 240 and the outer core 220 of the coaxial cable and the sheath 210, the outer core 220, and the insulator 230 and a toroidal coil 260. The toroidal coil 260 may be formed of a circular metal tube 250 and a toroidal coil 260,

The principle of measuring the voltage and current of electric power flowing in the inner core 240 of the coaxial cable is as follows. The voltage of the electric power flowing in the inner core 240 can be measured through a potential difference between the inner core 240 by the circular metal pipe 250 around the inner core and the ground. The current of the electric power flowing in the inner core 240 can be measured through the coil 260 responsive to the electromagnetic wave radiated from the inner core 240.

The sensing part applied to the general coaxial cable as described above is not separated from the electric field by the circular metal plate 250 for measuring the voltage of the inner core 240 in which the coil 260 for measuring the electric current transmits electric power, There may be a problem that voltage coupling occurs.

It is an object of the present invention to provide a power measuring apparatus and method for measuring a voltage and a current from a power line and a power measuring sensor for preventing a decrease in the accuracy of current measurement due to occurrence of voltage coupling through an electric field, .

According to an aspect of the present invention, there is provided a power measurement sensor including: a hole through which a power line for supplying electric power passes; a plurality of partition walls located outside the power line; And a coil which is located outside the partition and transmits a current induced by a magnetic field radiated from the power line to the outside, wherein each of the plurality of partition walls is intermittently located on a virtual closed curve surrounding the power line And at least two partition walls that shield the electric field radiated from the center axis of the power line toward the arc of the power line.

In an embodiment, the power line may provide power to a plasma processing chamber that utilizes plasma.

The power line may further include an insulating layer located outside the power line and blocking the power line from being in contact with oxygen.

In an embodiment, the hypothetical closed curve may include the shape of a circle.

In the embodiment, one circle in which one of the partition portions is located may have a concentric circle having a different diameter from another circle in which the other partition portion is located.

In an embodiment, each of the at least two barrier ribs may have a constant distance from the adjacent barrier ribs.

In an embodiment, the coil may comprise a toroidal form surrounding the power line.

In an embodiment, the voltage of the power line may be measured through a voltage sense line connected to the power line.

In an embodiment, the apparatus may further include the hole, the support member supporting the power line, the plurality of partition walls, and the coil.

In an embodiment, the coil may include a toroidal shape that penetrates the support several times and surrounds the power line.

In an exemplary embodiment, the plurality of partition walls may include three first partition walls located on the one circle, and three second partition walls located on another circle having a larger diameter than the one circle, Three second partitions may shield an electric field radiated from the central axis of the power line in a direction toward the arc of the power line through the non-continuous section of the three first partition walls.

In an embodiment, the shielding of the electric field may include a central angle of a arc formed by a second partition wall of one of the three second partition walls and another second partition wall adjacent to the first partition, a difference between the radius of the one circle and the radius of the other circle, May be determined according to the length of the barrier rib in a direction parallel to the power line.

In an embodiment, the central angle, the difference and the length may be calculated through an I-V decoupling ratio investigation.

The effect of the power measurement sensor according to the present invention will be described below.

According to at least one of the embodiments of the present invention, in measuring the voltage and the current from the power line, it is possible to prevent the accuracy of the current measurement from decreasing due to the occurrence of the voltage coupling through the electric field when measuring the current .

Figure 1 is a diagram of a typical plasma system for measuring input power and transferring maximum power to a plasma processing chamber through impedance matching.
2 is a view showing a sensing unit through a general coaxial cable.
3 is a view illustrating a power measurement sensor according to an embodiment of the present invention.
4 is a view illustrating a power measurement sensor according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals are used to designate identical or similar elements, and redundant description thereof will be omitted. The suffix "module" and " part "for the components used in the following description are given or mixed in consideration of ease of specification, and do not have their own meaning or role. In the following description of the embodiments of the present invention, a detailed description of related arts will be omitted when it is determined that the gist of the embodiments disclosed herein may be blurred. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. , ≪ / RTI > equivalents, and alternatives.

Terms including ordinals, such as first, second, etc., may be used to describe various elements, but the elements are not limited to these terms. The terms are used only for the purpose of distinguishing one component from another.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The singular expressions include plural expressions unless the context clearly dictates otherwise.

In the present application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a component, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

3 is a view illustrating a power measurement sensor according to an embodiment of the present invention.

3, the power measurement sensor 301 may include a hole through which a power line 310 for supplying power is passed, a plurality of pillar portions 326 to 328 and 336 to 338 located outside the power line, And may include coils 360 that are located outside the multiple-layer partition walls 326 to 328 and 336 to 338 and that transfer the current induced by the magnetic field radiated from the power line 310 to the outside.

In particular, the power line 310 may be a power line 310 that supplies power to a plasma processing chamber that utilizes the plasma.

A detailed description of each of the multiple-layer partition portions 326 to 328 and 336 to 338 is as follows.

Each of the multiple-layer partition portions 326 to 328 and 336 to 338 may be intermittently located on imaginary closed curves 322 and 332 surrounding the power line 310. That is, any one of the partition walls (e.g., 326 through 328) includes at least two intermittent partition walls (e.g., 326 through 328) on any one imaginary closed curve (e.g., 322) can do.

As shown in Figure 3, the dual-structured partitions 326 to 328 and 336 to 338 included in the two imaginary closed curves 322 and 332 are directed from the central axis of the power line 310 to the arc of the power line Lt; RTI ID = 0.0 > direction. ≪ / RTI >

The reason why the electric field radiated in the direction from the center axis of the power line 310 toward the arc of the power line must be shielded in measuring the electric current supplied through the power line 310 is as follows.

First, the current flowing in the power line 310 to be measured is a current flowing in the longitudinal direction of the power line 310, and the measurement of the current flowing in the power line 310 can be performed through electromagnetic induction.

Specifically, the measurement of the current through electromagnetic induction can be performed through a coil 360 in the form of a toroidal enclosing power line 310. This can be explained by Lenz's law and right handed screw rule (Ampere's law).

Lenz's law is the law of electromagnetic induction issued by the German scientist Heinrich Friedrich Emil Lenz (1804-1865) in 1834. The current generated by the electromagnetic induction can flow in a direction that hinders the change of the magnetic flux. Here, the magnetic flux can be 'the number of lines of magnetic force passing through a certain plane'. This Lentz law can be said to be the law of inertia that appears in electromagnetic science, 'Nature hates sudden change.'

Concretely, when the current flowing in the conductor (power line) 310 around the coil 360 approaches the direction toward the coil 360, the magnetic flux passing through the end face of the coil 360 (the " can do. At this time, the current induced in the coil 360 may flow in a direction that interferes with the increase of the magnetic flux passing through the end face of the coil 360. Conversely, if the current flowing in the conductor (power line) 310 around the coil 360 is moved away from the coil 360, the magnetic flux passing through the end face of the coil 360 can be reduced. At this time, the current induced in the coil 360 can flow in a direction that interferes with the reduction of the magnetic flux passing through the end surface of the coil 360, like the former.

The right-hand rule is the law of the direction of the magnetic field corresponding to the current and current published by the French physicist Andre-Marie Ampere (1775-1836).

The direction of the magnetic field corresponding to the current and the current direction at that time around the conductor (coil) 360 through which the current flows can not point in a direction parallel to each other. If the current flows in a straight line, the magnetic field can be placed in a circle around it. Between these two directions, there can be the same relationship as the relationship between the direction of rotation of the right-hand screw and the direction of travel.

When the direction of the flowing linear current is made to correspond to the traveling direction of the right screw, the direction of the magnetic field corresponding to the current can correspond to the rotating direction of the right screw at this time. This correspondence is the right-hand rule.

Or, this can be called the right-hand rule. According to the right-hand rule, when the right-hand thumb points to the direction of the current, a circular magnetic field in the direction of holding the wire (coil) 360 as the other finger can be positioned. That is, the direction of the thumb can correspond to the advancing direction of the right screw, and the direction of the restrained finger can correspond to the direction of rotation of the right screw.

In addition, even when a current flows along an arbitrary closed curve (coil) 360 without flowing through a straight line, the right-hand rule can be applied to a small conductive element on the closed curve.

For example, when a constant current flows through a circular conductor (coil) 360, and virtually dividing the circular conductor into finer lengths, it can be seen as if a current flows in a straight line with respect to the divided minute conductor elements . Accordingly, the right-hand rule can be applied to each minute conductor element.

When a current flows along an arbitrary closed curve (coil) 360, the magnetic field at all points can be obtained by superpositioning the direction and size of the magnetic field together. It can be formulated as Biot-Savart's law.

With respect to the center of the circular conductor (coil) 360 through which the current flows, the magnetic field can be positioned in the direction indicated by the thumb when the remaining finger is wound by subtracting the thumb in the direction of the current. This is the right-hand rule for the circular conductor.

The power measurement sensor according to the present invention measures the electric current flowing through the power line through the above-described Lenz's law and the right-hand rule, and the measurement can be implemented through the coil 360 of the toroidal form.

However, there may be some cautions. According to the results of Maxwell's equations, the electric field and the magnetic field are always orthogonal and coexist. Therefore, in order to measure the current in the longitudinal direction of the power line 310 of the power supplied through the power line 310, the power measurement sensor according to the present invention measures the current in the direction from the central axis of the power line 310 toward the arc of the power line, It may be necessary to shield the electric field.

Accordingly, the power measurement sensor according to the present invention may include a double-walled partition wall as a specific example corresponding to the multiple-layered partition wall portions 326 to 328 and 336 to 338, and these double- The electric current flowing in the electric power line can be precisely measured since the electric field radiated in the direction from the central axis of the power line to the arc of the power line can be shielded.

The power line 310 may include a conductor including at least one of copper (Cu), aluminum (Al), gold (Au), silver (Ag), and iron (Fe). The conductivity of the power line 310 may decrease if the power line 310 including the conductor is oxidized with oxygen.

The reduced-conductivity power line 310 may reduce the efficiency of the power measurement sensor. To prevent this, the power measurement sensor may further include an insulation layer 312 located outside the power line 310 and blocking the contact of the power line 310 with oxygen.

Here, the voltage of the power supplied through the power line 310 may be measured through the voltage sensing line 340 connected to the power line 310. At this time, the voltage sensing line 340 may be directly connected to the power line 310. As shown in FIG. 3, the voltage sensing line 340 may be connected to the outside through one of the barrier ribs 338.

The power measurement sensor according to the present invention may further include a power line 310, a plurality of partition partitions 326 to 328 and 336 to 338 and a support part 350 for supporting the coil 360, And in this case the coil 360 may extend through the support 350 several times and may include a toroidal shape surrounding the power line 310.

The voltage and current of the power supplied through the power line 310 may be input to the controller (not shown) through the voltage sensing line 340 and the coil 360. 1, a control unit (not shown) may generate a control signal for impedance matching with reference to the input voltage and current. Thereafter, the impedance matching unit (not shown) receives the control signal generated from the control unit (not shown) and adjusts the capacitor and the inductor value to implement the impedance matching.

4 is a view illustrating a power measurement sensor according to another embodiment of the present invention.

Referring to FIG. 4, a virtual closed curve of the power measurement sensor according to the present invention may include a circle shape 422, 432. For example, a power measurement sensor may include two or more partition portions 426 to 428 and 436 to 438, in which case a virtual closed curve where each of the partition portions 426 to 428 and 436 to 438 is located And may include circular shapes 422 and 432 of different diameters. At this time, the two circles 422 and 432 of different diameters can have a concentric relationship with each other.

One partition wall portion 426 to 428 may include at least two partition walls 426 to 428. Each of the at least two barrier walls (e.g., 427) may have a constant distance d from the other barrier walls (e.g., 426, 428) adjacent thereto. In this case, the voltage sensing line 440 may penetrate one partition (e.g., 438) to extend outwardly.

Specifically, the power measurement sensor according to the present invention includes three first partition walls 426 to 428 located on one circle 422 and a second partition 432 on the other circle 432 having a larger diameter than one circle 422 Folded partition portions 426 to 428 and 436 to 438 having three second partitioning walls 436 to 438, respectively. At this time, the three second partitions 436 to 438 pass through the non-continuous section of the three first partition walls 426 to 428 to generate an electric field radiated from the central axis of the power line 410 toward the arc of the power line It can be shielded.

In this case, the shielding of the electric field is caused by the central angle of the arc formed by the second partition wall 438 of one of the three second partition walls 436 to 438 and the other second partition wall 437 adjacent thereto, And the length H in a direction parallel to the power line 410 of the first bank 426 or the second bank 436. In this case,

On the other hand, the optimal values for the center angle (?), The difference in radius (D), and the length (H) can be calculated by examining the I-V decoupling ratio.

On the other hand, the sensing part applied to a general coaxial cable may have a problem that a coil for measuring a current is not insulated with respect to an electric field and a circular metal plate for measuring the voltage of the power line, so that voltage coupling occurs.

However, according to the power measurement sensor of the present invention, when measuring the voltage and the current from the power line, it is possible to prevent the occurrence of the voltage coupling through the electric field and to increase the accuracy of the current measurement .

The foregoing detailed description should not be construed in any way as being restrictive and should be considered illustrative. The scope of the present invention should be determined by rational interpretation of the appended claims, and all changes within the scope of equivalents of the present invention are included in the scope of the present invention.

Claims (13)

A hole through which a power line supplying electric power passes;
A plurality of partition walls positioned outside the power line; And
And a coil disposed outside the plurality of partition walls and transmitting a current induced by a magnetic field radiated from the power line to the outside,
Wherein each of the plurality of partition walls comprises:
And at least two partition walls that are intermittently located on a virtual closed curve surrounding the power line and that shield an electric field radiated from a central axis of the power line toward a circular arc of the power line. .
The method according to claim 1,
The power line
Wherein the power is supplied to a plasma processing chamber utilizing plasma.
The method according to claim 1,
Further comprising an insulating layer located outside the power line, the insulating layer interrupting contact of the power line with oxygen.
The method according to claim 1,
The hypothetical closed curve,
And a shape of a circle.
5. The method of claim 4,
One circle in which one of the partition walls is located,
And the other one of the plurality of partition walls is concentric with the other circle having a different diameter from each other.
The method according to claim 1,
Wherein each of the at least two partition walls comprises:
Wherein the distance between the adjacent partition walls is constant.
The method according to claim 1,
Wherein:
And a toroidal form surrounding said power line.
The method according to claim 1,
And a voltage sensing line connected to the power line for transmitting the voltage of the power line to the outside.
The method according to claim 1,
Further comprising: a hole provided in the hole, the power line, the plurality of partition walls, and a support for supporting the coil.
10. The method of claim 9,
Wherein:
Wherein the power measurement sensor includes a toroidal shape that passes through the support several times and surrounds the power line.
6. The method of claim 5,
The multi-layered partition wall portion
Three first partition walls located on the one circle; And
And three second partitions located on another circle having a larger diameter than the one circle,
The three second partition walls may be formed in a substantially rectangular shape,
And shields an electric field radiated from a central axis of the power line in a direction toward an arc of the power line through the non-continuous section of the three first partition walls.
12. The method of claim 11,
The shielding of the electric field,
A center angle of the arc formed by the second barrier rib of one of the three second barrier ribs and the adjacent second barrier rib,
The difference between the radius of one circle and the radius of the other circle, and
And the length of the first partition or the second partition in a direction parallel to the power line.
13. The method of claim 12,
The center angle, the difference,
IV < / RTI > decoupling ratio.

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